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Biomedical subjects

A Brand

Publications and source records attributed to A Brand.

At least 235 records · Page 13Linked to original sources
PubMed1990

Clonal B-cell populations in patients with idiopathic thrombocytopenic purpura.

Idiopathic thrombocytopenic purpura (ITP) may be associated with other autoimmune diseases and the development of lymphoproliferative malignancies. In Sjögren's disease, Graves' disease, and essential mixed cryoglobulinemia, which are also associated with the development of B-cell neoplasia, clonal B-cell expansions have been detected. Eleven patients with ITP were investigated for the presence of a clonal excess (CE) using kappa-lambda flow cytometry and DNA analysis for rearrangement of immunoglobulin heavy and light chain genes in blood and/or spleen lymphocytes. In 10 of 11 patients, clonal B-cell populations were found by one or both tests. In three of these patients, oligoclonal B-cell populations were suggested by the combined findings. In all four patients with a small paraproteinemia, the isotype was confirmed by either flow cytometry or DNA rearrangement analysis. Our data suggest that the oligoclonal expansions are not restricted to CD5+ B cells, as in the majority of patients this subset was below the detection level of flow cytometry or DNA rearrangement analysis. None of the patients developed clinical manifestations of malignant lymphoma during a follow-up period of 10 to 44 months after sampling. We conclude that clonal excess populations of B cells are not a unique feature of malignant lymphoma, but may occur in autoimmune diseases, suggesting a benign (oligo)clonal B-cell proliferation.

Adult↗
PubMed1990

[Biotechnology in perspective].

Biotechnology is a collective term for a large number of manipulations of biological material. Fields of importance in stock-keeping include: (1) manipulation of reproductive processes; (2) genetic manipulation of macro-(farm) animals and micro-organisms and (3) manipulation of metabolism. Fitting in biotechnological findings in breeding-stock farming has repercussions in several fields such as the relationship between producers and the ancillary and processing industries, service industries, consumers and society as a whole. The use of biotechnical findings will also require further automation and adaptation of farm management. Biotechnology opens up a new area and new prospects for farm animal husbandry. These can only be regarded as positive when they take a permanent development of the entire section into account.

Animal Husbandry↗
PubMed1990

Rejection of bone-marrow graft by recipient-derived cytotoxic T lymphocytes against minor histocompatibility antigens.

A female patient showed rejection of a T-lymphocyte-depleted bone-marrow graft from her phenotypically HLA-identical father. Before bone-marrow transplantation, there was strong recipient anti-donor cellular cytotoxic reactivity directed against several minor histocompatibility (mH) antigens, including the male-specific H-Y antigen. After conditioning treatment, no recipient anti-donor cytotoxic activity could be detected, and good graft function was shown a month after transplantation. Thereafter, however, graft function deteriorated rapidly, while recipient-derived anti-donor cellular cytotoxic reactivity, against similar mH antigens, reappeared. The recipient-derived cytotoxic T lymphocytes could completely inhibit growth of donor haemopoietic progenitor cells both before and after bone-marrow transplantation. Thus, cytotoxic T lymphocytes can survive very intensive conditioning regimens, and residual recipient cytotoxic T lymphocytes directed against mH antigens expressed on donor haemopoietic progenitor cells may cause graft rejection after HLA-identical T-lymphocyte-depleted bone-marrow transplantation.

Adult↗
PubMed1990

Increased numbers of circulating haematopoietic progenitor cells after treatment with high-dose interleukin-2 in cancer patients.

Immunotherapy with recombinant interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells has been applied to patients with metastatic cancers for its antitumour activity. In the present study we investigated the effects of in vivo administration of IL-2 (3 x 10(6) U/m2/d, continuously i.v.) on haematopoiesis. Six patients with disseminated renal cell carcinoma, treated with IL-2 and LAK cells, were monitored for the numbers of white blood cells and circulating haematopoietic progenitor cells (HPC). During IL-2 treatment lymphopenia developed, followed by lymphocytosis after discontinuation of IL-2 infusions. IL-2 administration also resulted in neutrophilia and eosinophilia. Absolute numbers of circulating HPC declined markedly during IL-2 treatment. However, after completing IL-2 infusions, the numbers of circulating erythroid (BFU-E), myeloid (CFU-GM) and multipotential progenitor cells (CFU-GEMM) strongly increased, reaching a maximum after 5 d (day 10 from the start of IL-2 treatment). This increase did not result from repeated leucaphereses, since patients treated with IL-2 alone showed a similar response. In comparison with pretreatment levels the pool of circulating HPC expanded about 20-fold. This study illustrates that IL-2 treatment has a biphasic effect on the frequency of circulating BFU-E, CFU-GM and CFU-GEMM, causing a decrease during IL-2 infusion, followed by an increase after IL-2 administration. The total number of progenitor cells harvested by four consecutive leucaphereses is in the range that is commonly used for peripheral blood stem cell autografting.

Carcinoma, Renal Cell↗
PubMed1990

Management of severe hemolytic disease with ultrasound-guided intravascular fetal transfusions.

Between January 1987 and March 1989, 22 fetuses with severe hemolytic disease were treated with 64 ultrasound-guided intrauterine intravascular transfusions. Eighteen infants survived and are doing well. In 12 fetuses, hydropic changes were present at the first transfusion; 9 of these survived. In 8 of the 10 fetuses with a gestational age less than 26 weeks, intrauterine treatment was successful.

Blood Transfusion, Intrauterine↗
PubMed1990

High-dose intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy: a double-blind, placebo-controlled, crossover study.

We discontinued high-dose intravenous immunoglobulin treatment (IVIg) in 7 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) who seemed to have responded to IVIg. After discontinuation of treatment, all 7 patients deteriorated. We then randomized the patients to IVIg or placebo (albumin) treatment in a double-blind crossover study. The clinical condition of all patients improved after IVIg and did not improve after placebo treatment. The mean time lapse from the end of the trial treatment to the occurrence of deterioration was 6.4 weeks after treatment with IVIg and 1.3 weeks after treatment with placebo. This selected group of patients with CIDP had a beneficial response to IVIg.

Adult↗
PubMed1990

Effect of severity of systemic signs during the acute phase of experimentally induced Escherichia coli mastitis on milk production losses.

The objectives were to describe the systemic signs during the acute phase of experimental Escherichia coli mastitis and to relate these with losses in milk production during the reconvalescent period. Eleven cows, 20 to 30 d postpartum, were inoculated with 10(4) cfu of E. coli O157 in rear quarters. Heart rate, rectal temperature, frequency and amplitude of rumen contractions, plasma Zn and Fe concentrations, and counts of E. coli were used to monitor severity of disease during the acute phase. Areas under curves of clinical parameters, plasma Zn and Fe concentrations, and counts of E. coli were calculated during 36, 120, and 125 h postinoculation, respectively. Areas under curves of milk production were calculated during 21 d postinoculation. Losses in total daily milk production were related positively with areas under curves of heart rate, rumen amplitude, counts of E. coli in secreta from inoculated quarters, and plasma Zn and Fe concentrations. These parameters may prove suitable to establish an accurate prognosis for returning to milk production cows suffering from acute or peracute E. coli mastitis and to evaluate efficacy of drugs in experimental mastitis.

Acute Disease↗
PubMed1990

Preinfection functions of blood polymorphonuclear leukocytes and the outcome of experimental Escherichia coli mastitis in the cow.

The relationship between preinfection functions of blood neutrophils and outcome of experimental Escherichia coli mastitis was studied in 11 cows. Random migration, chemotaxis, phagocytosis, and chemiluminescence by neutrophils were determined in white blood cell suspensions, and in purified neutrophil suspensions. The course of E. coli mastitis (10(4) E. coli 0:157 in rear quarters) was monitored using clinical parameters, counts of E. coli in mastitic secretion, and milk production. Regressions were calculated for areas under curves of these parameters and preinfection activities of neutrophils. Chemiluminescence by nonstimulated neutrophils in white blood cell suspensions was negatively correlated with counts of E. coli in secretion and with losses in milk production. The chemotactic differential in white blood cell suspensions minus the chemotactic differential in purified suspensions of neutrophils referred to as delta varied from -.66 to +.50, indicating, respectively, inhibition and stimulation of chemotactic activity of neutrophils in white blood cell suspensions. Delta correlated negatively with counts of E. coli in mastitis secretion, inhibition of the amplitude of rumen contractions, and losses in milk production. We hypothesize that a factor in white blood cell suspensions may be involved in the down-regulation of the migratory response of neutrophils during E. coli mastitis.

Animals↗
PubMed1990

Population dynamics of bulk milk somatic cell counts.

The population dynamics for bulk milk SCC in 27,000 Dutch dairy farms was studied over 6 yr; SCC declined markedly in 1984 and 1985. This coincided with the introduction of the quota system in the European Community. The CV of SCC was .36, ranging from .15 to .89. Month of year had a significant effect on SCC with the highest SCC in October and the lowest in April. The dynamics of the annual SCC were modeled with a state transition model. Farmers managing herds with a fairly low SCC (less than 450,000) had a reasonable chance to remain in these states. Herds with a higher annual SCC were much more variable. The model simulated, the potential reactions of the farmers to the decrease of the SCC limit from 750,000 to 500,000 starting January 1, 1989. The simulations showed a further decrease in mean annual SCC, although the number of farms in the category with a very low SCC (less than 150,000) is not likely to increase. In all simulations an increased number of farmers will receive a penalty due to the more strict regulations of the European Community.

Animals↗
PubMed1990

Growth of Escherichia coli in milk from endotoxin-induced mastitic quarters and the course of subsequent experimental Escherichia coli mastitis in the cow.

The objective of this study was to assess growth of Escherichia coli in milk from endotoxin-induced mastitic quarters and to relate the in vitro findings to the course of experimental E. coli mastitis. Whole and skim milks from 24 rear quarters of 12 cows were inoculated with E. coli 0:157 and incubated at 38 degrees C. Growth of E. coli 0:157 was not inhibited in milk collected from rear quarters immediately prior to endotoxin infusion. However, growth inhibition occurred in all but one whole mastitic milk samples collected from mastitic quarters 18 h after infusion of .1 mg of endotoxin. Skim milk samples from mastitic quarters were bactericidal in four cows (7 quarters), whereas growth occurred in skim mastitic milk from 17 quarters of nine cows. Rear quarters of all cows were inoculated with 10(4) cfu of E. coli 0:157 19 h after the quarters had been infused with endotoxin. Clinical parameters and milk production were monitored during 36 h and 21 d, respectively. None of the inoculated quarters developed signs of inflammation, and secreta from inoculated quarters were bacteriologically negative after 48 h. Therefore, growth-inhibitory property of skim milk from endotoxin-induced quarters was apparently not a suitable parameter to monitor differences in susceptibility to E. coli mastitis.

Animals↗
PubMed1990

Risk factors for clinical mastitis in herds with a low bulk milk somatic cell count. 1. Data and risk factors for all cases.

The incidence rate of clinical mastitis in 125 herds with a low annual bulk milk SCC (less than 150,000 cells/ml) was modeled using a Poisson regression model. The rate of clinical mastitis was significantly associated with some variables that increased the exposure to environmental microorganisms: poor cubicle cleanliness increased the mastitis rate; rubber mats in cubicles were associated with a higher incidence; and drinking water from sources other than public water also increased the rate of mastitis. Other variables may be associated with host resistance: an increasing percentage of cows leaking milk increased the rate of mastitis; postmilking teat disinfection was associated with a higher incidence of clinical mastitis; and a high frequency of cubicle disinfection was also associated with more mastitis. Three other variables were associated with the rate of mastitis: breed (Holstein-Friesian had a lower incidence than the Meuse-Rhine-Yssel breed); use of sugar beet pulp in the ration increased the mastitis rate; and in herds with high milk production a higher incidence of mastitis was observed. These items are discussed in respect to their causal relation to clinical mastitis.

Animals↗
PubMed1990

On the down-regulation of cross-bridges occurring as changes in the cycling rate during tonic smooth muscle contractions.

As regards cross-bridge down-regulation, the following statements may summarize the results of our experiments: 1) The time course of cross-bridge down-regulation is the initial high turn-over rate followed by a continuous retardation without any distinct loss in force generation. These mechanisms allowed a rapid force development and an improvement in force maintenance. 2) Cross-bridge down-regulation was seen in the tracheal preparation of both the rat and the guinea pig. As indicated by the greater time constants of the post-vibration force recovery, the cross-bridge cycling rate seems to be distinctly lower in the guinea pig than in the rat trachea. 3) Cross-bridge down-regulation only occurs in smooth muscle preparations with intact cell membranes. This result would seem to hint that the sarcoplasmatic calcium concentration and/or the intactness of the cell membrane might be essential for producing cross-bridge down-regulation. 4) The recovery from cross-bridge down-regulation requires a rest period of more than 10s. The cross-bridges remain down-regulated during this time even after an increase in the sarcoplasmatic calcium concentration which was induced by a subsequent stimulus. This result indicates that changes in the sarcoplasmatic calcium cannot explain all the problems arising during cross-bridge down-regulation.

Acetylcholine↗
PubMed1990

Painless acute pancreatitis subsequent to anticholinesterase insecticide (parathion) intoxication.

Painless acute hemorrhagic pancreatitis, manifested only by an ileus, is described in two of nine patients after ingestion of parathion, a poisonous anticholinesterase insecticide. Other investigators have shown in animal experiments that parathion increases pancreatic intraductal pressure and stimulates pancreatic secretion. Such described cases may be designated pathologically as clinical examples of acute obstruction pancreatitis. Hemoperfusion is usually chosen to treat parathion intoxication, but carries the risk of causing hemorrhages in acute hemorrhagic pancreatitis. Clinically, it is therefore important to determine, by way of enzyme estimations and imaging procedures, whether acute pancreatitis has occurred following parathion intoxication, so that the prognosis for the poisoned patient is comprehensive enough and the antidated measures applied do not aggravate the pancreatic condition.

Acute Disease↗
PubMed1989

Lymphokine-activated killer cell functions in patients with leukemic B-lymphoproliferative diseases.

Nine patients with leukemic B-lymphoproliferative diseases (B-LPD) were evaluated for development of in vitro recombinant interleukin-2 (rIL-2)-activated killer (LAK) cells. B-cell cultures were established from peripheral blood mononuclear cells (PBMNCs) containing 63% +/- 29% malignant cells. Short-term cultures were tested after 5-day activation with 500 U rIL-2/mL. Long-term cultures were maintained for 4 to 6 weeks by weekly addition of 500 U rIL-2 and autologous irradiated feeder cells. In the first week, the cells decreased considerably in the long-term cultures but thereafter cells proliferated (mainly T cells) on the average 300-fold (range 30- to 1,000-fold). In the short-term cultures, there was a 36% reduction of malignant B cells. In long-term cultures, B cells were reduced from 63% to 8%; three cultures still contained greater than 15% B cells. The CD16-positive cell percentage was comparable in both types of cultures and ranged from 2% to 17%. Effector cells lysing the natural killer (NK)-sensitive cell line K562 could be induced in all patients. Except in patients with chronic lymphocytic leukemia (CLL) and high malignant cell numbers, NK activity was already restored after 5 days. Optimal NK activity was obtained after 1.5 to 2.5 weeks. LAK cells killing NK-resistant lymphoma cell lines showed optimal activity after 2 to 3 weeks of culture. However, LAK cells killing greater than 10% of autologous malignant cells were obtained in only one third of the patients. The discrepancy between strong cytolytic activity against the NK-sensitive (K562) target cells obtained in all patients and the cytotoxic activity against NK-resistant cell lines contrasts with the poor development of LAK cells against autologous tumor cells. This discrepancy does not appear to be explained by soluble inhibitory factors released during the tumor cultures, as allogeneic LAK cells were not inhibited by supernatants from patients' cultures. Further investigations are warranted to reveal cell-mediated inhibition by tumor cells or suppressor cells.

Antigens, CD↗
PubMed1989

Natural course of atrial septal aneurysm in children and the potential for spontaneous closure of associated septal defect.

Atrial septum aneurysm (ASA), usually involving the region of the fossa ovalis, has rarely been described in children. In this study, the incidence and natural course of this anomaly were prospectively evaluated in 3,500 children referred for echocardiographic examination. ASA was found in 35 patients, 19 female and 16 male (1.0%). Patients were 6 years of age or younger at the time of diagnosis and 18 were neonates. None of the 750 children with normal echocardiograms had ASA. The most common associated lesion was atrial septal defect (ASD), which occurred in 24 of the 35 patients (69%). Other associated cardiac lesions were ventricular septal defect in 10, pulmonary stenosis in 5, patient ductus arteriosus in 4 and coarctation or interruption of the aorta with subaortic membrane in 2. No clinical complications were associated with ASA. Six patients with complex heart disease died. When associated with ASD, the direction of the ASA motion and that of the shunt found by Doppler echocardiography were similar. Fourteen patients with ASD were followed for 0.5 to 4 years. In 8 the ASD closed and in 6 the ASA disappeared. In 6 patients the ASD and ASA persisted until the end of the follow-up (p less than 0.01). Thus, the incidence of ASA in children in this series was higher than previously presumed and usually was associated with other cardiac anomalies, mainly ASD. In children, ASA tends to disappear with age and may have a role in spontaneous closure of associated ASD.

Abnormalities, Multiple↗