Cell salvage transfusion Health Dictionary

A generally slow growing malignant epithelial tumour, which has potential to invade and metastasise, especially if untreated.... basal cell carcinoma

See TRANSFUSION – Transfusion of blood.... blood transfusion

The smallest unit of living material that can function independently.... cell

A method of treating newborn infants with HAEMOLYTIC DISEASE. Blood is taken out of the baby through the umbilical vein and is replaced with the same quantity of blood from a donor that is compatible with the mother’s blood. The procedure is repeated several times to get rid of damaged cells while maintaining the infant’s blood volume and keeping its red cell count constant. (See also TRANSFUSION.)... exchange transfusion

Those embryonic cells with the potential to develop into ova (see OVUM) or spermatozoa (see SPERMATOZOON).... germ cell

See HYPERNEPHROMA.... renal cell carcinoma

Malignant tumour of squamous epithelium of skin, which generally spreads and metastasises.... squamous cell carcinoma

Stem CELLS develop a few days after an egg (ovum) is fertilised by a spermatozoon and starts developing to form an EMBRYO. These master cells are crucial to the development of a normal embryo. They contain a specialised ENZYME that gives them the facility to divide inde?nitely, developing into the many di?erent specialised cells that comprise the various tissues in the body – for example, skin, blood, muscle, glands or nerves.

In a highly signi?cant advance in research, a scienti?c team in the United States obtained stem cells from newly formed human embryos

– donated by women who had become pregnant after successful in vitro fertilisation – and successfully cultivated these cells in the laboratory. This achievement opened the way to replicating in the laboratory, the various specialised cells that develop naturally in the body. UK government legislation constrains the use of human embryos in research (see ETHICS) and the ethical aspects of taking this stem-cell culture technique forwards will have to be resolved. Nevertheless, this discovery points the biological way to the use of genetic engineering in selecting di?erentiated specialised cells from which replacement tissues could be grown for use as transplants to rectify absent or damaged tissues in the human body.

Research into potential use of stem cells has raised expectations that in the long term they may prove to be an e?ective regenerative treatment for a wide range of disorders including PARKINSONISM, ALZHEIMER’S DISEASE, type-2 diabetes (see under DIABETES MELLITUS), myocardial infarction (see HEART, DISEASES OF), severe burns, osteoporosis (see under BONE, DISORDERS OF) and the regeneration of blood to replace the need for BONE MARROW TRANSPLANT. Recent research has shown that adult stem cells may also be stimulated to produce new cell lines. If successful, this would eliminate the need to use embryos and thus resolve existing ethical dilemmas over the use of stem cells.... stem cell

See: ARTERITIS. ... giant cell arteritis

The administration of any ?uid into a person’s vein using a drip. This apparatus facilitates a continuous injection in which the ?uid ?ows by force of gravity from a suspended bottle, via a tube that is ?xed to a hollow needle inserted into a vein (usually in the front of the elbow). Saline solution, PLASMA and whole BLOOD (see below) are the most commonly administered ?uids. Saline is used to restore ?uid to a seriously dehydrated individual (see DEHYDRATION) and may be used as a temporary measure in SHOCK due to blood loss while the appropriate type of blood is being obtained for transfusion. Saline may also be useful as a way of administering a regular supply of a drug over a period of time. Plasma is normally used as a temporary measure in the treatment of shock until appropriately matched blood is available or if for any reason, such as for a patient with severe burns, plasma is preferable to blood.

Transfusion of blood is a technique that has been used since the 17th century – although, until the 20th century, with a subsequent high mortality rate. It was only when incompatibility of BLOOD GROUPS was considered as a potential cause of this high mortality that routine blood-testing became standard practice. Since the National Blood Transfusion Service was started in the United Kingdom (in 1946), blood for transfusion has been collected from voluntary, unpaid donors: this is screened for infections such as SYPHILIS, HIV, HEPATITIS and nvCJD (see CREUTZFELDT-JAKOB DISEASE (CJD)), sorted by group, and stored in blood-banks throughout the country.

In the UK in 2004, the National Blood Authority – today’s transfusion service – announced that it would no longer accept donations from anyone who had received a blood transfusion since 1980 – because of the remote possibility that they might have been infected with the PRION which causes nvCJD.

A standard transfusion bottle has been developed, and whole blood may be stored at 2–6 °C for three weeks before use. Transfusions may then be given of whole blood, plasma, blood cells, or PLATELETS, as appropriate. Stored in the dried form at 4–21 °C, away from direct sunlight, human plasma is stable for ?ve years and is easily reconstituted by adding sterile distilled water.

The National Blood Authority prepares several components from each donated unit of blood: whole blood is rarely used in adults. This permits each product, whether plasma or various red-cell concentrates, to be stored under ideal conditions and used in appropriate clinical circumstances – say, to restore blood loss or to treat haemostatic disorders.

Transfusion of blood products can cause complications. Around 5 per cent of transfused patients suffer from a reaction; most are mild, but they can be severe and occasionally fatal. It can be di?cult to distinguish a transfusion reaction from symptoms of the condition being treated, but the safe course is to stop the transfusion and start appropriate investigation.

In the developed world, clinicians can expect to have access to high-quality blood products, with the responsibility of providing blood resting with a specially organised transfusion service. The cause of most fatal haemolytic transfusion reactions is a clerical error due to faulty labelling and/or failure to identify the recipient correctly. Hospitals should have a strict protocol to prevent such errors.

Arti?cial blood Transfusion with blood from donors is facing increasing problems. Demand is rising; suitable blood donors are becoming harder to attract; the processes of taking, storing and cross-matching donor blood are time-consuming and expensive; the shelf-life is six weeks; and the risk of adverse reactions or infection from transfused blood, although small, is always present. Arti?cial blood would largely overcome these drawbacks. Several companies in North America are now preparing this: one product uses puri?ed HAEMOGLOBIN from humans and another from cows. These provide oxygen-carrying capacity, are unlikely to be infectious and do not provoke immunological rejections. Yet another product, called Oxygene®, does not contain any animal or human blood products; it comprises salt water and a substance called per?ubron, the molecules of which store oxygen and absorb carbon dioxide more e?ectively than does haemoglobin. Within 24 hours of being transfused into a person’s bloodstream, per?ubron evaporates and is harmlessly breathed out by the recipient. Arti?cial blood is especially valuable in that it contains no unwanted proteins that can provoke adverse immunological reactions. Furthermore, it is disease-free, lasts for up to three years and is no more expensive than donor blood. It could well take the place of donor blood within a few years.

Autologous transfusion is the use of an individual’s own blood, provided in advance, for transfusion during or after a surgical operation. This is a valuable procedure for operations that may require large transfusions or where a person has a rare blood group. Its use has increased for several reasons:

fear of infection such as HIV and hepatitis.

shortages of donor blood and the rising cost of units of blood.

substantial reduction of risk of incompatible transfusions. In practice, blood transfusion in the UK is

remarkably safe, but there is always room for improvement. So, in the 1990s, a UK inquiry on the Serious Hazards of Transfusion (SHOT) was launched. It established (1998) that of 169 recently reported serious hazards following blood transfusion, 81 had involved a blood component being given to the wrong patient, while only eight were the result of viral or bacterial infections.

There are three ways to use a patient’s own blood in transfusion:

(1) predeposit autologous donation (PAD) – taking blood from a patient before operation and transfusing this blood back into the patient as required during and after operation.

(2) acute normovalaemic haemodilution (ANH) – diluting previously withdrawn blood and thus increasing the volume before transfusion.

(3) perioperative cell salvage (PCS) – the use of centrifugal cell separation on blood saved during an operation, particularly spinal surgery where blood loss may be considerable.

The government has urged NHS trusts to consider the introduction of PCS as a possible adjunct or alternative to banked-blood transfusion. In one centre (Nottingham), PCS has been used in the form of continuous autologous transfusion for several years with success.

Exchange transfusion is the method of treatment in severe cases of HAEMOLYTIC DISEASE OF THE NEWBORN. It consists of replacing the whole of the baby’s blood with Rh-negative blood of the correct blood group for the baby.... transfusion

A columnar secretory cell occurring in the EPITHELIUM of the respiratory and intestinal tracts.

The cells produce the main constituents of MUCUS.... goblet cell

This is the basic cell from which all types of blood cells originate. Its appearance is believed to be similar to that of a LYMPHOCYTE.... haemopoietic stem cell

See NEURON(E).... nerve cell

A type of cell found in one highly malignant form of lung cancer. The cell is small and either oval or round. The nucleus stains darkly and the cytoplasm is sparse and di?cult to identify. Oat-cell, or small-cell, carcinoma of the bronchus is usually caused by smoking, and comprises around 30 per cent of all bronchial cancers. It responds to radiotherapy and chemotherapy but, because the growth has usually spread widely by the time it is diagnosed, the prognosis is poor. Results of surgery are unsatisfactory.... oat cell

That fraction of the blood’s total volume made up of red cells. The packed cell volume is found by centrifuging blood in a tube and measuring the depth of the column of red cells as a fraction of the whole column of blood. (See also HAEMATOCRIT.)... packed cell volume

See ERYTHROCYTES; BLOOD.... red blood cell

See OAT CELL.... small-cell carcinoma

A specialised white cell (lymphocyte) responsible for cell-mediated immunity. See also T-lymphocyte.... t-cell

Abnormal ERYTHROCYTES which are large and ‘?oppy’ and have a ringed appearance, similar to that of a target, when stained and viewed under the microscope. This change from normal may occur with iron-de?ciency ANAEMIA, liver disease, a small SPLEEN, haemoglobinopathies (disorders of HAEMOGLOBIN), and THALASSAEMIA.

A target cell is also a cell that is the focus of attack by macrophages (killer cells – see MACROPHAGE) or ANTIBODIES; it may also be the site of action of a speci?c hormone (see HORMONES).... target cell

See lymphocyte.... b-cell

See LEUCOCYTES.... white blood cell

The processes by which cells multiply. Mitosis is the most common form of cell division, giving rise todaughter cells identical to the parent cells.

Meiosis produces egg (see ovum) and sperm cells that differ from their parent cells in that they have only half the normal number of chromosomes.... cell division

A growth comprised of immature sperm cells in the male testis or of immature ova in the female ovary. A seminoma is one type of germ cell tumour (see testis, cancer of).... germ cell tumour

A type of cell that plays an important part in allergy.

In an allergic response, mast cells release histamine.... mast cell

See TRANSFUSION – Transfusion of blood.... autologous blood transfusion

A type of white blood cell that circulates through the body and is able to detect the presence of the foreign agents. Once exposed to an antigen on the agent, these cells differentiate into plasma cells to produce antibody.... b-lymphocyte (or b-cell)

A defence mechanism involving the coordinated activity of two subpopulations of TLymphocytes, helper T-Cells and killer T-Cells. Helper T-Cells produce a variety of substances that stimulate and regulate other participants in the immune response. Killer T-Lymphocytes destroy cells in the body that bear foreign antigens (e.g. cells that are infected with viruses or other microorganisms).... cell-mediated immunity

See TRANSFUSION.... continuous autologous transfusion

A method of autologous blood TRANSFUSION – using a patient’s own blood, salvaged during a surgical operation – instead of conventional blood-bank transfusion.... perioperative cell salvage

These have almost completely replaced BONE MARROW TRANSPLANT, used to treat malignancies such as LEUKAEMIA and LYMPHOMA for the past 20 years. The high doses of CHEMOTHERAPY or RADIOTHERAPY used to treat these diseases destroy the bone marrow which contains stem cells from which all the blood cells derive. In 1989 stem cells were found in the blood during recovery from chemotherapy. By giving growth factors (cytokines), the number of stem cells in the blood increased for about three to four days. In a peripheral-blood stem-cell transplant, these cells can be separated from the peripheral blood, without a general anaesthetic. The cells taken by either method are then frozen and returned intravenously after the chemotherapy or radiotherapy is completed. Once transplanted, the stem cells usually take less than three weeks to repopulate the blood, compared to a month or more for a bone marrow transplant. This means that there is less risk of infection or bleeding during the recovery from the transplant. The whole procedure has a mortality risk of less than 5 per cent – half the risk of a bone marrow transplant.... peripheral-blood stem-cell transplants

This procedure is sometimes used instead of blood TRANSFUSION. PLASMA – the ?uid part of blood from which the cells have been separated

– may be dried and in powder form kept almost inde?nitely; when wanted it is reconstituted by adding sterile distilled water. In powder form it can be transported easily and over long distances. Transfusion of plasma is especially useful in the treatment of SHOCK. One advantage of plasma transfusion is that it is not necessary to carry out testing of blood groups before using it.... plasma transfusion

The cells that produce the MYELIN sheath of the AXON of a medullated NERVE. They are wrapped around a segment of the axon, forming concentric layers.... schwann cell

See LYMPHOMA.... t-cell lymphoma

A form of anaemia growing into an acute social problem, affecting people of African, Asian, and Mediterranean origin. Thalassaemias are caused by defects of a gene that produces the globin part of haemoglobin. Such defects in the DNA can now be detected in the womb before birth. The name derives from sickle-shaped cells instead of circular red blood cells. Few sufferers survive beyond their 40th year.

Symptoms. Unhealthy pallor, listlessness, sore tongue, dizziness, vague aches and pains, rapid pulse and breathing, tinnitus, palpitation. The skull may be disproportionately large, resistance to infection feeble, chances of survival poor. This form of anaemia is linked with defective colour vision. Impaired liver function. Stunted growth, great pain. Sufferers have a higher risk of infection.

Malaria. Sufferers are less likely to die of malaria because their red cells do not support the growth of malaria parasites very well.

Carriers: Carriers of the sickle-cell gene can now be identified by a simple blood test.

Treatment. No specifics exist but supportive herbal treatment has been known to increase output of red cells and raise haemoglobin levels:– Red Clover flowers, Yellow Dock, Echinacea, Burdock, Wild Indigo, Gentian, Nettles, Birch leaves, Sage, Walnut leaves, Centaury, Gota Kola (Indian Pennywort). Alternatives:– Tea. Mix equal parts: Iceland Moss, Nettles, Red Clover flowers. 2 teaspoons to each cup boiling water; infuse 15 minutes; 1 cup morning and evening.

Decoction. Mix equal parts; Echinacea, Walnut leaves, Balm of Gilead buds; 1 teaspoon to each cup water gently simmered for 20 minutes. Half-1 cup, cold, 3 times daily, before meals.

Tablets/capsules. Sarsaparilla. Ginseng. Iceland Moss. Red Clover. Echinacea. Gentian.

Powders. Formula: Echinacea 1; Fringe Tree half; Ginseng half; White Poplar bark 1. Dose: 500mg (two 00 capsules or one-third teaspoon) thrice daily before meals.

Liquid extracts. Formula. Echinacea 2; Dandelion 1; Oat Husk (avena sativa) 1. Mix. Dose, 1-2 teaspoons before meals, in water or one of the above teas or decoctions.

Tinctures. Same combination. Dose: 2-3 teaspoons.

Dong quai. See entry.

Pollen. Claimed to be of value.

Diet. Dandelion coffee. Molasses. Desiccated liver. Calf liver, fresh. Green leafy vegetables contain chlorophyll, iron and folic acid. Cider vinegar. Dried beans, apricots and shellfish. Dandelion leaves in salads. Milk, eggs, meats, Soya. Carrot juice to increase red cells.

Supplements. Daily. Vitamin B12. Vitamin C, 1g; Folic acid 400mcg, Floradix. Of particular value: Vitamin E 400iu. Zinc.

Note: Those at risk should submit themselves for screening. The disease cannot be cured but can be controlled largely by orthodox measures and sometimes by natural medicine. ... anaemia: sickle cell

A growth composed of cells that produce various hormones. These cells, amine precursor uptake and decarboxylation (APUD) cells, occur in different parts of the body. Some tumours of the thyroid gland, pancreas, and lungs are cell tumours, as are a carcinoid tumour (see carcinoid syndrome) and phaeochromocytoma (a type of adrenal tumour).... apud cell tumour

The use of a person’s own blood, donated earlier, for blood transfusion. Autologous transfusion eliminates the slight but serious risk of contracting a serious infectious illness from contaminated blood. There is no risk of a transfusion reaction occurring as a result of incompatibility between donor and recipient blood. Up to 3.5 litres of blood can be removed and stored in several sessions at least 4 days apart and up to 3 days before planned surgery. Blood may be salvaged during surgery, filtered and returned to the circulation, reducing the need for transfusion of donated blood.... blood transfusion, autologous

Given three months to live, Jason Winters, terminal cancer patient, was suffering from infiltrating squamous cell carcinoma wrapped round his carotid artery. Refusing major surgery, he travelled the world in search of native remedies. He was able to contact people who put him on the track of Wild Violet leaves, Red Clover flowers (Trifolium pratense) and leaves of the Chaparral bush (Larrea divaricata). The story of how he infused them, together with a well- known spice, is dramatically recorded in his book “Killing Cancer”. After a spectacular recovery, remission has lasted for over 15 years and others have benefited from his experience.

Treatment by oncologist. ... cancer – squamous cell carcinoma

An inherited blood disease in which the red blood cells contain haemoglobin S, an abnormal type of haemoglobin. This crystallizes in the capillaries, making red cells sickle-shaped and fragile, and leading to haemolytic anaemia. The abnormal cells are unable to pass easily through tiny blood vessels. The blood supply to organs is blocked intermittently, causing sickle cell crises. The disease affects mainly black people.Symptoms usually appear after age 6 months, often beginning with painful swelling of the hands and feet. Chronic haemolytic anaemia causes fatigue, headaches, shortness of breath on exertion, pallor, and jaundice. Sickle cell crises start suddenly; they are sometimes brought on by an infection, cold weather, or dehydration, but may also occur for no apparent reason. The sufferer may experience pains (especially in the bones), blood in the urine (from kidney damage) or damage to the lungs or intestines. If the brain is affected, seizures, a stroke, or unconsciousness may result.

In some affected children, the spleen enlarges and traps red cells at a particularly high rate, causing a life-threatening form of anaemia. After adolescence, the spleen usually stops functioning, increasing the risk of infection in those affected.

Diagnosis is made from examination of a blood smear and electrophoresis.

Supportive treatment may include folic acid supplements, and penicillin and immunization to protect against infection.

Life-threatening crises are treated with intravenous infusions of fluids, antibiotics, oxygen therapy, and analgesic drugs.

If the crisis still does not respond, an exchange blood transfusion may be performed.

This may be done regularly for people who suffer frequent severe crises.... sickle cell anaemia

See blood transfusion, autologous.... transfusion, autologous

(APC) a cell, such as a *dendritic cell or a *macrophage, that processes antigen for presentation to a T lymphocytes (see helper T cell).... antigen-presenting cell

(blood corpuscle) any of the cells that are present in the blood in health or disease. The cells may be subclassified into three major categories, namely red cells (*erythrocytes); white cells (*leucocytes), which include granulocytes, lymphocytes, and monocytes; and *platelets (see illustration). The blood cells account for approximately 40% of the total volume of the blood in health; red cells comprise the vast majority.... blood cell

(echinocyte) a red blood cell (erythrocyte) with abnormal small thorny projections. See crenation.... burr cell

(perikaryon) the enlarged portion of a *neuron (nerve cell), containing the nucleus. It is concerned more with the nutrition of the cell than with propagation of nerve impulses.... cell body

a machine that aspirates blood lost during surgery and immediately spins, washes, and filters it for retransfusion back into the patient’s body (see autotransfusion). The process, called intraoperative cell salvage, is used in surgery that has significant blood loss, such as orthopaedic and vascular surgery and Caesarean section, and avoids the costs and risks of *allogeneic transfusion.... cell saver

molecules on the surface of cell membranes that are responsible for most cellular functions directly related to their immediate environment. Many have very precise functions of adhesion (see adhesion molecules), metabolic exchange, hormone reception, respiration, and immune reactions. Cell-to-cell exchanges involve specialized surface structures (junctions), which form a communicating nexus.... cell-surface molecules

(clear-cell adenocarcinoma) a variant of *adenocarcinoma that tends to arise from the kidneys or the female genital tract. In the latter case it is linked to intrauterine exposure to *diethylstilbestrol during the 1950s and 1960s and takes the form of a vaginal cancer, which can be treated by radical surgery followed by radiotherapy.... clear-cell carcinoma

a group of lymphomas in which abnormal T *lymphocytes are concentrated in the skin. The most common form is *mycosis fungoides.... cutaneous t-cell lymphoma

a type of T *lymphocyte that destroys cancerous cells, virus-infected cells, and *allografts. Cytotoxic T cells recognize peptide antigens attached to proteins that are encoded by the *HLA system.... cytotoxic t cell

a type of haemopoietic cell with specialized antigen-presenting functions. The head and neck are common sites for dendritic cell pathology. See antigen-presenting cell.... dendritic cell

see ovum.... egg cell

n. any of the gastrin-secreting cells of the stomach lining located predominantly in the gastric *antrum. Gastrin stimulates the production of gastric acid by parietal cells in the stomach. Increased G-cell activity is associated with the formation of duodenal ulcers and the *Zollinger-Ellison syndrome.... g-cell

any large cell, such as a *megakaryocyte. Giant cells may have one or many nuclei.... giant cell

an abnormal white blood cell that has the appearance of an immature lymphocyte with fine hairlike cytoplasmic projections around the perimeter of the cell. It is found in a rare form of leukaemia (hairy-cell leukaemia) most commonly occurring in young men.... hairy cell

a type of T *lymphocyte that plays a key role in cell-mediated immunity by recognizing foreign antigen on the surface of *antigen-presenting cells when this is associated with the individual’s *MHC antigens, having been processed by antigen-presenting cells. Helper T cells stimulate the production of *cytotoxic T cells, which destroy the target cells.... helper t cell

an androgen-producing tumour of the ovary found in older women and often resulting in *virilization. Such tumours are so called as they tend to occur around the area of the ovary where the blood vessels enter (the hilum). They are usually small and are treated by surgical removal, with resolution of most of the symptoms.... hilar cell tumour

a malignant tumour of the thyroid gland that arises from Hürthle (or Askanazy) cells, altered follicular cells of the gland that have large nuclei and stain deeply with eosin (these cells are also found in benign nodules and Hashimoto’s disease). Hürthle cell carcinoma is not as common as papillary, follicular, or anaplastic thyroid carcinomas (see thyroid cancer). [K. W. Hürthle (1860–1945), German histologist]... hürthle cell tumour

see luteinizing hormone.... interstitial-cell-stimulating hormone

a group of autoantibodies directed against components of the insulin-secreting beta cells of the pancreas. They are usually detectable in the blood of people presenting with type 1 diabetes. Antibodies against *glutamic acid decarboxylase (GAD) in the beta cells have become a more specific test for islet cell antibodies, to help confirm a diagnosis of type 1 diabetes.... islet cell antibodies

a new technique still under evaluation for curing type 1 *diabetes mellitus, which involves the injection of donated cells from the pancreatic *islets of Langerhans into the liver, where it is hoped they will seed and survive. The transplanted cells then take over insulin production from the recipient’s diseased pancreas.... islet cell transplantation

any tumour arising in a cell of the pancreatic *islets of Langerhans. These tumours, which include *insulinomas, *glucagonomas, and *somatostatinomas, form one of the two major subclasses of gastrointestinal neuroendocrine tumours, the other being the *carcinoid tumours.... islet cell tumour

overgrowth of cells of the *reticuloendothelial system. This includes disorders previously called histiocytosis X, including eosinophilic granuloma, Hand–Schüller–Christian disease, and Letterer–Siwe disease. [P. Langerhans (1847–88), German physician and anatomist]... langerhans cell histiocytosis

a long-lived lymphocyte that is formed following primary infection. It enables a faster and more robust immune response following a second exposure to the antigen.... memory cell

(NK cell) a type of *lymphocyte that is able to kill virus-infected cells and cancerous cells and mediates rejection of bone-marrow grafts. NK cells are a part of natural (or innate) *immunity. Their function is regulated by a balance between activating receptors, which recognize proteins on cancerous or virus-infected cells, and inhibitory receptors specific for certain molecules encoded by the *HLA system.... natural killer cell

see natural killer cell.

nm symbol for *nanometre.... nk cell

(NSCLC) any type of lung cancer other than *small-cell lung cancer. Such cancers include *adenocarcinoma of the lung, large-cell carcinomas, and squamous-cell carcinoma of the lung.... non-small-cell lung cancer

a posterior ethmoidal sinus air cell (see paranasal sinuses). They are surgically important because of their proximity to the optic nerve and internal carotid artery. [A. Onodi (1857–1919), Hungarian rhinolaryngologist]... onodi cell

a type of neuron found in the *cerebral cortex, with a pyramid-shaped cell body, a branched dendrite extending from the apex towards the brain surface, several dendrites extending horizontally from the base, and an axon running in the white matter of the hemisphere.... pyramidal cell

a large binucleate cell that is characteristic of *Hodgkin’s disease. [D. Reed Mendenhall (1874–1964), US pathologist; C. Sternberg (1872–1935), Austrian pathologist]... reed–sternberg cell

(Treg cell) a type of T *lymphocyte that suppresses immune responses.... regulatory t cell

a cell that is not undergoing division. See interphase.... resting cell

surgical measures to palliate the worst effects of a tumour but with no aim to effect a cure.... salvage procedure

(drepanocytosis) a hereditary blood disease that mainly affects people of African ancestry but also occurs in the Mediterranean region and reaches high frequencies in parts of Saudi Arabia and India. It occurs when the sickle-cell gene has been inherited from both parents and is characterized by the production of an abnormal type of *haemoglobin – sickle-cell haemoglobin (Hbs) – which precipitates in the red cells when the blood is deprived of oxygen, forming crystals that distort the cells into the characteristic sickle shape: this process is known as sickling. An excess of sickle cells in the circulation results in blockage of small blood vessels, producing episodes of severe pain (a sickle-cell crisis). Sickle cells are rapidly removed from the circulation, leading to anaemia and jaundice. There is no satisfactory treatment; the highest mortality is in childhood but some patients may live to an age of 60–70 years.

The carrier condition (sickle-cell trait) occurs when the defective gene is inherited from only one parent. It generally causes no symptoms but confers some protection from malaria, which accounts for the high frequency of the gene in malarious areas. If a general anaesthetic is to be given to a patient with this condition, the anaesthetist should be alerted.... sickle-cell disease

progressive renal disease developing in 5–8% of patients with *sickle-cell disease. Infarcts in the cortex can occur with sickle-cell crises and present with pain and haematuria. Acute or more insidious damage to the medulla will lead to a urinary concentrating defect and later to papillary necrosis and/or fibrosis. Occlusion of vessels within the glomerular capillary tuft leads to a secondary form of *focal segmental glomerulosclerosis and can present with the *nephrotic syndrome.... sickle-cell nephropathy

(SCLC) a type of bronchial carcinoma characterized by small cells (or oat cells), small round or oval cells with darkly staining nuclei and scanty indistinct cytoplasm. Small-cell carcinoma is usually related to smoking and accounts for about one-quarter of bronchial carcinomas; it carries a poor prognosis due to early distant spread, typically to bones, liver, and brain. Treatment is primarily with chemotherapy and radiotherapy and paraneoplastic symptoms (see paraneoplastic syndrome) from *ectopic hormone production are common. Compare non-small-cell lung cancer.... small-cell lung cancer

see Reed–Sternberg cell.... sternberg–reed cell

a type of T *lymphocyte that prevents an immune response by B cells or other T cells to an antigen.... suppressor t cell

a form of cancer that affects the urothelium, which lines the urinary collecting system of the kidney, ureters, bladder, and the proximal part of the urethra. It is the most common type of bladder cancer.... transitional cell carcinoma

see regulatory T cell.... treg cell

(TTTS) a condition in which communicating vessels in the shared placenta of monochorionic twins (see chorionicity) divert blood to one fetus (the recipient) from the other (the donor), resulting in one fetus with increased blood volume and one anaemic fetus. It complicates 15% of monochorionic twin pregnancies, and a system of ultrasound staging has been developed to assess the severity of the syndrome. TTTS is associated with a high perinatal mortality rate. There is significant morbidity and poor neurodevelopmental outcome in surviving infants due to complications of the disease itself and the high preterm birth rate that invariably accompanies this condition. A range of treatments, including *amnioreduction, *septostomy, and laser ablation of the communicating vessels, have led to an improvement in overall perinatal survival rates.... twin-to-twin transfusion syndrome