Biomedical subjects
Publications and source records attributed to D M McCarthy.
Why do (NZB x NZW)F1 mice develop an autoimmune lupus-like syndrome? The second exons of the class II genes of NZB and NZW are identical to their counterparts of H-2d and H-2u haplotypes. Several lines of evidence suggest that this allows the production of a mixed haplotype molecule, I-E alpha dE beta z, and that this molecule plays a key role in the development of autoimmunity.
Rhizopus oryzae was the causative organism in a fatal case of rhinocerebral and then pulmonary mucormycosis in a patient cured of her underlying leukaemia by bone marrow transplantation. We discuss the risk factors involved and the need for maintaining a high index of suspicion of fungal infection in the late post-transplant period.
We reviewed ten hands in nine patients who had enzymatic fasciotomy for Dupuytren's contracture, with an average follow-up of 6.5 years. While all patients were initially satisfied with the results, the disease recurred quite rapidly to pre-operative levels in seven patients over the subsequent two to three years.
Physicians using nonsteroidal anti-inflammatory drugs (NSAIDs) are concerned that effective anti-inflammatory doses cause few gastrointestinal side effects. Among the causes of discontinuing therapy, upper gastrointestinal symptoms and the development of 'ulcer' complications are major concerns; endoscopic findings in asymptomatic users are not. Initial symptoms, poorly correlated with endoscopic findings, are relieved by anti-ulcer drugs and ameliorate with time of NSAID use in most patients. Symptoms accompanied by epigastric tenderness, or unrelieved by H2 antagonists, or resulting in cessation of NSAID therapy are more predictive of underlying ulcers. Complications probably arise in several ways, including as hemorrhages due to interference with platelet function, and as complications due to exacerbations of underlying ulcer disease or of ulcers caused by the NSAIDs. Pathogenesis and effective prophylaxis (yet to be established) may therefore vary in different patients, a clinical dilemma.
DAB486IL-2 is a genetically engineered fusion protein consisting of a portion of diphtheria toxin fused to human IL-2. It is specifically cytotoxic for tumor cells which bear high-affinity IL-2 receptors (IL-2R). DAB389IL-2 is a similarly constructed hybrid protein which is smaller than DAB486IL-2 and is slightly more potent in vitro. We have developed a murine model of IL-2R-expressing malignancy to study the in vivo efficacy of these genetically engineered cytotoxins. Following intravenous administration of CP3 cells, C57BL/6 mice develop tumors which are lymphatic in distribution. When mice are injected i.v. with 10(6) CP3 cells, 90% of the animals show signs of observable tumor by day 10 to 20; death occurs in 50% of untreated animals by day 30. Intravenous treatment of mice with DAB486IL-2 (10 micrograms daily for 10 days), beginning 24 hr after administration of CP3 cells, increases mean survival time by approximately 50%. In comparative studies, DAB389IL-2 is more potent in vivo than DAB486IL-2, with approximately 90% of treated animals with no evidence of tumor at 60 days. The mechanism of action of tumor inhibition by DAB486IL-2 is specific, since treatment of animals which have IL-2R-negative EL4 tumors has not resulted in increased survival time. In addition, treatment of such tumors with DAglu53B486IL-2, a fusion protein which can bind to the IL-2R but is incapable of inhibiting protein synthesis, is ineffective.
Explore the source record for details and available documents.
Helicobacter pylori infection with active gastritis is comparably common in non-steroidal anti-inflammatory drug (NSAID) users and controls. The prevalence of active acute gastritis and its severity relate to H. pylori infection and not to use or non-use of NSAIDs. In individual patients active gastritis may deteriorate during long-term NSAID therapy but is rare in aspirin users. Among NSAID users those with H. pylori gastritis appear to have more dyspeptic symptoms, repeated intolerance to different NSAIDs, and often a history of ulcer disease. For current ulcers, NSAID use, chemical gastritis, and active gastritis due to H. pylori are independent risk factors. For gastric ulcer the risks are additive. For duodenal ulcer only H. pylori is a clearly defined risk factor: duodenal ulcers may not occur in H. pylori-negative NSAID users. In gastroduodenal mucosa NSAIDs may augment acute inflammation caused by H. pylori, and inflammation may exacerbate the biochemical injury to these tissues caused by NSAIDs.
Research in epidemiology and related fields highlights three factors contributing to a high prevalence of complications of ulcer disease in the elderly, namely anti-inflammatory drugs (aspirin and NSAIDs), type B gastritis due to H. pylori infection, and smoking; these factors also increase the prevalence of both GU and DU. The major dangers with ulcer disease arise from continued exposure to the causative risk factors, absent or insidious symptoms, difficulties in diagnosis, late presentations, high rates of complications (often the presenting features), high preoperative and perioperative mortality, and serious postoperative morbidity (especially in smokers). Empiric therapy and the use of diagnoses such as nonulcer dyspepsia invite additional hazards. Once diagnosed and adequately treated, ulcers in the elderly behave similarly to those in younger subjects matched for risk factors, and they respond well to treatment. In high-risk elderly patients without previous or active ulcer disease, misoprostol may be used to prevent gastric ulcers; other benefits of the drug await clarification. In those with previous or active ulcer disease, H2-antagonists given long-term in higher doses appear preferable. Side effects of antiulcer drugs are rarely serious and are easily managed by dose reductions or changes in products. The major benefits to the management of ulcers in the elderly come from increased vigilance on the part of physicians.
Megakaryocyte growth-promoting activity (MK-GPA) was scored on a scale of 0-3 in the serum of 23 patients up to 120 d following bone marrow transplantation (BMT) for leukaemia. Nine of 19 allografts and two of four autografts had thrombocytopenia requiring platelet transfusion more than 30 d after BMT. There was a close correlation between MK-GPA and platelet count. MK-GPA reached a maximum before day 30 after BMT but remained elevated in patients with persisting thrombocytopenia secondary to poor engraftment, graft-versus-host disease (GVHD) or relapse. Recent platelet transfusion did not suppress serum MK-GPA. Two of four patients undergoing autologous BMT for acute myeloid leukaemia (AML) showed delayed platelet recovery and persistence of MK-GPA in the serum. Seven further AML remission marrows were tested for megakaryocyte production before or after autologous BMT, using pooled sera with known MK-GPA activity. Megakaryocyte generation was reduced before BMT and absent in post transplant samples. This failure of MK production was not corrected by T-cell depletion or by the presence of adherent cells from normal marrow. We conclude that thrombocytopenia after BMT is associated with an appropriate increase in MK-GPA levels in response to a reduction in the megakaryocyte pool rather than the platelet pool, and that persisting thrombocytopenia after autologous BMT is due to decreased numbers of available megakaryocyte precursors.
Explore the source record for details and available documents.
Nonsteroidal anti-inflammatory drugs (NSAIDs) cause acute diffuse injury to the gastroduodenal mucosa, and also cause chronic focal ulcers that may bleed or perforate without warning symptoms. Acute and chronic lesions are distinct, are pathogenetically different, respond differently to drugs, and require different management strategies. The principal rationale for antiulcer therapy in NSAID users is to prevent or reduce potentially fatal outcomes; to date no evaluated drug meets this criterion for efficacy. Antacids and H2-receptor antagonists, based on open uncontrolled studies, appear to heal both gastric and duodenal ulcers, and maintain them healed during continued NSAID use; larger gastric ulcers show delayed healing with conventional doses of H2-receptor antagonists during NSAID therapy. No such delay occurs with omeprazole therapy. The suggests that if NSAID-associated gastric ulcers are treated with H2-receptor antagonists, larger doses should be given for longer periods. In patients with no pre-existing ulcer disease, H2-receptor antagonists given prophylactically prevent duodenal but not gastric ulcers; sucralfate does the same. In individuals without peptic ulcer disease taking NSAIDs, misoprostol, given as prophylaxis, reduces the development of gastric ulcers; its beneficial effects on ulcer healing or symptoms during continued NSAID therapy, or its ability to prevent duodenal ulcers or ulcer complications, are not established. Because of diarrhea, the 400 micrograms/day dosage is recommended, especially in the elderly.
Explore the source record for details and available documents.
Normal blood mononuclear cells incubated in the presence of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in suspension culture showed increased differentiation to adherent macrophages. The effect was specific to 1,25-(OH)2D3 as the closely related metabolite 25-hydroxyvitamin D3 did not increase macrophage numbers. Giant multinuclear cells were observed in increased numbers in 1,25-(OH)2D3-treated cultures. However this effect was not specific to 1,25-(OH)2D3 but due to cell crowding as these cells were also plentiful when cultures without 1,25-(OH)2D3 were incubated at high cell densities. Increased numbers of macrophages were seen after six days of incubation; this effect of 1,25-(OH)2D3 occurred also if the mononuclear cells were depleted of T-cells or exposed to X-irradiation at doses up to 25Gy. Addition of 1,25-(OH)2D3 to cultures in semi-solid media did not, however, increase the numbers of monocyte-macrophage colonies. These results suggest that the target cell for 1,25-(OH)2D3 is of the monocyte-macrophage lineage and is at a relatively late stage of maturation.
STUDY OBJECTIVE: To evaluate criteria of positivity for and usefulness of both the secretin and calcium gastrin-provocative tests in patients with the Zollinger-Ellison syndrome. DESIGN: Prospective trial in consecutive patients. SETTING: Referrals to a clinical research center. PATIENTS: Consecutive sample of 80 patients with the Zollinger-Ellison syndrome. INTERVENTION: Kabi-secretin (2 U/kg body weight) given by intravenous bolus and calcium gluconate (10%) (54 mg/kg.h [5 mg/kg.h of calcium]) given by continuous intravenous infusion for 3 hours. Serum gastrin measured at -15, and -1 minutes before, and 2, 5, 10, 15, 20, and 30 minutes after secretin, or every 30 minutes for 3 hours during the calcium infusion. Serum calcium and serum gastrin were measured simultaneously during the calcium infusion. MEASUREMENTS AND MAIN RESULTS: There was no significant difference in the responses of patients with different extents or locations of the tumor, presence or absence of multiple endocrine neoplasia, type-I, or with fasting gastrin less than or greater than 1000 pg/mL. In patients with fasting gastrin of less than 1000 pg/mL, the sensitivity of the secretin test using the criterion of an increase in gastrin of at least 110 pg/mL was 93% (CI, 76% to 99%) and for an increase of 200 pg/mL it was 85% (CI, 66% to 96%), (P greater than 0.05). With the calcium infusion test, the sensitivity using the criterion of an increase of 395 pg/mL was 43%, (CI, 23% to 66%) and for an increase of 50% was 74% (CI, 52% to 90%), (P less than 0.01). The calcium infusion test was positive in 33% of patients with a negative secretin test. With the secretin test, 75% of patients had a positive response by 5 minutes, 95% by 10 minutes, 100% by 15 minutes, and 6% only at 2 minutes. With calcium infusion, patients had positive responses at 120 to 180 minutes. CONCLUSIONS: The secretin test is preferred over the calcium test because of its greater sensitivity and simplicity. The recommended criteria are a 200 pg/mL increase for the secretin test and a 395 pg/mL increase for the calcium test. The calcium test should be reserved for patients having a negative secretin test, gastric acid hypersecretion, and a strong clinical suspicion of the Zollinger-Ellison syndrome.
The (NZB x NZW)F1 mouse strain develops a syndrome of accelerated autoimmunity including severe renal disease and early death. Evidence suggests that class II molecules play a central role in this process. Previous studies have suggested that the NZW strain contributes at least one gene to the development of accelerated autoimmunity that is linked to the H-2 complex, and antibodies to murine class II molecules have been used to ameliorate disease in (NZB x NZW)F1 mice. We therefore wished to sequence the class II molecules from NZW mice to identify any unique sequences that may contribute to disease development. We constructed oligonucleotide primers corresponding to the 5' and 3' regions of the second exon of class II genes from a variety of haplotypes, and used these primers in a polymerase chain reaction to sequence the second exon of the NZW I-A alpha, I-A beta, and I-E beta genes. We report that the second exons of NZW I-A alpha, I-A beta, and I-E alpha are identical to their counterparts of the previously sequenced u haplotype, and that the second exon of NZW I-E beta is identical to its counterpart from u except for a single base change that results in a substitution of arginine for threonine at amino acid 72. This base and amino acid are identical to those found at the same positions in the s haplotype.
The immunosuppressive effects of the sedative drug thalidomide have been utilised in a variety of immune disorders. In the present study, 6 patients were treated who developed graft-versus-host disease (GvHD) following allogeneic bone marrow transplantation (BMT) with thalidomide and in a dose range of 200-600 mg daily. Two of 3 patients with chronic GvHD showed clear improvement, whereas none of the 3 patients with acute GvHD derived unequivocal benefit. Although based on a small number of patients, these data suggest that thalidomide may find a useful place in the therapy of GvHD, perhaps specifically in the chronic form of this disorder.
PURPOSE: The purpose of this work was to evaluate the proposed usefulness of a standard meal-stimulated gastrin provocative test in: (1) distinguishing Zollinger-Ellison syndrome (ZES) from antral syndromes; (2) localizing duodenal gastrinomas; or (3) suggesting that patients with multiple endocrine neoplasia type I (MEN-I) may have an increased incidence of antral syndromes. PATIENTS AND METHODS: Seventy-four consecutive patients with ZES referred to the National Institutes of Health were studied prospectively. The extent and location of gastrinomas, acid secretory studies, and the presence or absence of MEN-I were determined and correlated with the results of the gastrin response to standard meal provocative testing. RESULTS: For patients with fasting serum gastrin levels less than 1,000 pg/mL (n = 43), only 44% had a less than 50% increase over the pre-meal value, which is reported to be the typical response in ZES, and 40% had a 50% to 99% increase. Furthermore 16% had a 100% or greater increase, 9% a 150% or greater increase, and 5% a 200% or greater increase, which overlaps with values reported to be characteristic of 98%, 92%, and 46% of patients with antral syndromes. Results did not differ for patients with or without MEN-I, depend on the extent of the gastrinoma (duodenal versus pancreatic gastrinomas), the presence of previous gastric surgery or type of gastric surgery, or for patients with fasting serum gastrin concentrations greater than or equal to 1,000 pg/mL or less than 1,000 pg/mL. studies of four patients before and after resection of the gastrinoma, who prior to surgery had a greater than 100% increase in gastrin secretion after the meal, demonstrated that all patients had a less than 100% increase postoperatively even though no gastric resection was done. CONCLUSIONS: Approximately half of the patients with ZES have a greater than 50% increase in serum gastrin concentration following a standard test meal and one fifth have a 100% or greater increase. Therefore, they cannot be distinguished on this basis from patients with antral syndromes. The increased serum gastrin level after the meal in these patients with ZES appears to be due to the gastrinoma. Furthermore, the current study provides no evidence for the proposals that antral syndromes are more common in patients with MEN-I, that gastric surgery affects the meal response in patients with gastrinomas, or that the meal test is useful in localizing duodenal gastrinomas.