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D Bass

Publications and source records attributed to D Bass.

At least 37 records · Page 2Linked to original sources
PubMed1998

Hydrolysis of surfactant-associated phosphatidylcholine by mammalian secretory phospholipases A2.

Hydrolysis of surfactant-associated phospholipids by secretory phospholipases A2 is an important potential mechanism for surfactant dysfunction in inflammatory lung diseases. In these conditions, airway secretory phospholipase A2 (sPLA2) activity is increased, but the type of sPLA2 and its impact on surfactant function are not well understood. We examined in vitro the effect of multiple secretory phospholipases A2 on surfactant, including their ability to 1) release free fatty acids, 2) release lysophospholipids, and 3) increase the minimum surface tension (gammamin) on a pulsating bubble surfactometer. Natural porcine surfactant and Survanta were exposed to mammalian group I (recombinant porcine pancreatic) and group II (recombinant human) secretory phospholipases A2. Our results demonstrate that mammalian group I sPLA2 hydrolyzes phosphatidylcholine (PC), producing free fatty acids and lysophosphatidylcholine, and increases gammamin. In contrast, mammalian group II sPLA2 demonstrates limited hydrolysis of PC and does not increase gammamin. Group I and group II secretory phospholipases A2 from snake venom hydrolyze PC and inhibit surfactant function. In summary, mammalian secretory phospholipases A2 from groups I and II differ significantly from each other and from snake venom in their ability to hydrolyze surfactant-associated PC.

Animals↗
PubMed1998

Wernicke encephalopathy and beriberi during total parenteral nutrition attributable to multivitamin infusion shortage.

OBJECTIVE: Wernicke encephalopathy (WE) is an acute neurologic disorder characterized by a triad of ophthalmoplegia, ataxia, and mental confusion. WE is attributable to thiamine (vitamin B1) deficiency. Beriberi is the systemic counterpart of thiamine deficiency and often manifests in cardiovascular collapse. WE is usually associated with alcoholism and malnutrition. It has also been seen in people with gastrointestinal diseases with malabsorption. Patients who have received total parenteral nutrition (TPN) without proper replacement of thiamine have also developed WE. Since November 1996, there has been a shortage of multivitamin infusion (MVI). Many patients who were on chronic TPN with MVI ceased to receive the MVI and were converted to an oral form of the multivitamin. As a result, there have been several reports of children and adults on TPN who have developed WE as a result of thiamine deficiency. With this case report, we bring to attention the association of the MVI shortage and WE. Early diagnosis of WE is important, because if it is treated with thiamine in the acute stages, the neurologic and cardiovascular abnormalities can be reversed. CASE REPORT: We report a 20-year-old female patient with Crohn's disease who developed WE as a result of thiamine deficiency. She had Crohn's disease since age 9 years and was on chronic TPN. Two months before admission, MVI was discontinued in the TPN because of the shortage of its supply. An oral multivitamin tablet was substituted instead. She was admitted to the hospital for persistent vomiting. In the hospital, she continued to receive TPN without MVI, but continued taking an oral multivitamin preparation. Two weeks after admission, she developed signs of WE including diplopia, ophthalmoplegia, nystagmus, and memory disturbance. She also developed hypotension that was thought to be caused by beriberi. She was treated with 50 mg of intravenous thiamine. Within hours of the intravenous thiamine, her hypotension resolved. The day after the infusion, she no longer complained of diplopia, and her ophthalmoplegia had improved dramatically. Magnetic resonance imaging showed several areas of abnormally high signal on T2-weighted images in the brainstem, thalamus, and mamillary bodies. The topographic distribution of these changes was typical of WE. After 2 months, her mental status and neurologic status had recovered completely. CONCLUSION: WE and thiamine deficiency should be considered in all patients with malabsorption, malnutrition, and malignancies. WE from thiamine deficiency can occur as a result of cessation of MVI in the TPN infusion. Even if an oral multivitamin preparation is given instead of MVI, patients with malabsorption may not absorb thiamine adequately. Prompt diagnosis of WE is important because it is potentially fatal and readily treatable with thiamine supplementation. Early recognition of WE may be more difficult in children, because the classic triad of symptoms may not develop fully. Magnetic resonance imaging may be useful in these cases to confirm the diagnosis of WE. Because the shortage of MVI is expected to be a long-term, there are likely to be more cases of WE in the pediatric population of TPN-dependent children. Because there is no shortage of intravenous thiamine, it should be administered with TPN even if MVI is not available.

Administration, Oral↗
PubMed1997

Expression of mucosal homing receptor alpha4beta7 by circulating CD4+ cells with memory for intestinal rotavirus.

The integrin alpha4beta7 mediates lymphocyte binding to mucosal addressin cell adhesion molecule-1, and its expression defines lymphocytes capable of trafficking through the intestines and the intestinal lymphoid tissues. We examined the ability of discrete alpha4beta7(hi) and alpha4beta7- subsets of circulating memory phenotype (CD45RA-) CD4+ T cells to proliferate in response to rotavirus, a ubiquitous intestinal pathogen. alpha4beta7(hi) memory (CD45RA-) CD4+ T cells displayed much greater reactivity to rotavirus than alpha4beta7- memory or naive (CD45RA+) CD4+ T cells. In contrast, alpha4beta7- memory cells were the predominant population responsive to mumps antigen after intramuscular vaccination. Our results are consistent with the conclusion that natural rotavirus infection, an enteric pathogen, results in a specific circulating memory CD4+ response that is largely limited to the gut-homing alpha4beta7+ subpopulation. This phenotype is not shared with memory cells elicited by intramuscular immunization (shown here) or by skin contact allergens. The results support the hypothesis that gut trafficking memory CD4+ T cells comprise cellular memory for intestinal antigens and suggest that regulated expression of alpha4beta7 helps target and segregate intestinal versus systemic immune response.

Adult↗
PubMed1997

G(ee): a new hepatitis virus.

Hepatitis G virus (HGV) is a newly discovered virus of the flavivirus family. It has recently been identified by two independent laboratories. We review the discovery of this virus and summarize the molecular biology techniques that were employed to isolate and sequence HGV Although HGV can cause both acute and chronic hepatitis and is found in approximately 1% of U.S. blood donors, it is unclear whether HGV is a major cause of hepatic pathology. At present, it is difficult to screen blood donors for HGV routinely due to the unavailability of a reliable ELISA test, and so it is unclear what action blood banks should take regarding this virus. It is possible that HGV may be linked to extrahepatic diseases.

Flaviviridae↗
PubMed1996

Transfusion and cytomegalovirus-associated AIDS-defining disease in hemophiliacs. Hemophilia Malignancy Study.

BACKGROUND: Whether transfusion increases the risk of AIDS-defining cytomegalovirus (CMV) infection (CMV AIDS) in immunosuppressed patients is not known. Because of concerns about the risk of transfusion transmission of CMV and potential exposure to multiple strains of CMV through transfusion, the National Hemophilia Foundation recently recommended that CMV-negative blood be used in human immunodeficiency virus-positive hemophiliacs, regardless of their CMV serologic status. Although the multiple strains of CMV cause different CMV disease manifestations in transplant recipients, there are no data on CMV disease in human immunodeficiency virus-positive hemophiliacs. STUDY DESIGN AND METHODS: It was hypothesized that if the transmission of CMV through transfusion causes CMV disease in human immunodeficiency virus-positive hemophiliacs, then hemophiliacs with CMV AIDS would be more likely to have received transfusions than those with AIDS-defining disease not caused by CMV (non-CMV AIDS). The number and type of transfusions were evaluated in 334 hemophiliacs with AIDS (35 with CMV AIDS and 299 with non-CMV AIDS) enrolled in the multicenter Hemophilia Malignancy Study. RESULTS: There were no differences between hemophiliacs with CMV AIDS and those with non-CMV AIDS in age, type, and severity of hemophilia; the proportion receiving transfusions; or the mean number of units transfused. These findings persisted after correction for transfusion practice, (i.e., CMV-unscreened blood vs. CMV-negative and/or white cell-reduced blood). There was no difference between the groups in CMV lgG titers or in the proportion who were CMV seropositive, and there was no difference between these parameters in those who had received transfusion(s) and those who had not. CONCLUSION: Transfusion appears to have little, if any, effect on the development of CMV AIDS or CMV lgG seroprevalence in patients with hemophilia.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Comparative study of the role of serum levels of p53 antigen and its tumor cell concentration in colon cancer detection.

The role of serum levels of p53 antigen in detection of colon cancer was studied in different groups of cancer and noncancer patients and was compared with the results of immunohistochemical analyses. The p53 antigen was isolated from the human serum as a cytoplasmic fraction using the recently described new type of columns for affinity chromatography, gel fiberglass columns (Zusman and Zusman, 1995). Its concentration was detected by high performance liquid chromatography. The serum level of the p53 antigen significantly increased in cancer patients (3.6 mg ml(-1)) as compared to its concentration in patients with benign tumors (1.7 mg ml(-1)) or in patients with noncancer disorders (0.49 mg ml(-1)), and this was found to be a result of higher concentration of p53 protein in tumor cells. Coefficient of correlation between cellular concentration of p53 protein and its serum level was 0.44 in noncancer lesions and 0.48 in cancer patients. Serum levels of p53 antigen was shown to be highly active either in patients with noncancer lesions or in patients with cancer (r = 0.46 and 0.51 respectively), whereas the cell determination of p53 protein was effective only among noncancer patients (r = 0.61) but not in cancer patients (r = 0.22). The findings suggests that serum determination of p53 antigen can perhaps reveal this oncoprotein already in the early stages of cancer or even predict the putative development of cancer. The possibility to use the serum-levels of p53 antigen in the follow up patients with chronic diseases and to detect transformation of these diseases into cancer, or monitoring former cancer patients in order to detect as early as possible the incidence of recurrent cancer is discussed.

Antigens, Neoplasm↗
PubMed1995

Sexually transmitted diseases in children and evidence of sexual abuse.

During the period June 1989 to March 1991, laboratory evidence of sexually transmitted diseases (STDs) was found in 107 patients at the Red Cross War Memorial Children's Hospital in Cape Town. Data was available on 96 patients aged 23 months to 14 years (mean 75.9 months). Vaginal discharge was the most frequent presenting symptom (76%), particularly in those less than 5 years of age (90%). Although a history of abuse was not given on presentation in 62%, evidence of abuse was subsequently elicited in 67% of patients. Neisseria gonorrhoeae was the most common sexual pathogen (61 isolates, 8 penicillin resistant), followed by G vaginalis (17 isolates), Trichomonas vaginalis (7 infections), and T pallidum (9 TPHA positive, 5 with VDRL 1:4 or higher). Chlamydia trachomatis was demonstrated by immunofluorescence in 14 children. Multiple STDs were demonstrated in 10 patients. Although evidence of CSA was not found in all patients with STDs it was likely that the vast majority of patients had acquired these infections by CSA. Symptomatic prepubertal children with G vaginalis isolates should be investigated for CSA. Chlamydial immunofluorescence tests did not assist the diagnosis of CSA in children and should not be used, as they have no medicolegal significance.

Age Distribution↗
PubMed1995

The minimum alveolar concentration of isoflurane in patients undergoing bilateral tubal ligation in the postpartum period.

BACKGROUND: The minimum alveolar concentration (MAC) of volatile anesthetics is decreased during pregnancy, but MAC in the early postpartum period has not been reported. The aim of this study was to determine the MAC of isoflurane and to evaluate the relation between MAC and serum progesterone and beta-endorphin in patients after delivery. METHODS: Eight patients undergoing elective bilateral tubal ligation during general anesthesia in the early postpartum period (< 12 h postpartum) and eight patients undergoing this procedure in the late postpartum period (12-25 h postpartum) were studied. Eight patients undergoing bilateral tubal ligation more than 6 weeks after delivery served as control subjects. Anesthesia was induced with propofol and maintained with isoflurane in oxygen to a steady end-tidal concentration of 0.8-1.0 vol% for 10 min. Reaction to a standardized electric stimulation applied to the forearm was graded as positive (gross or delayed movement) or negative. By using the bracketing technique, the concentration of isoflurane was increased or decreased by 0.1 vol%, depending on the positive or negative responses. RESULTS: The MAC (mean +/- SD) in patients in the early postpartum period was significantly less (0.75 +/- 0.17 vol%) than that in control subjects (1.04 +/- 0.12 vol%; P < 0.01) and that in patients in the late postpartum period (0.95 +/- 0.2 vol%; P < 0.05). The difference in MAC values between late postpartum and control was not significant (P > 0.05). There was an inverse correlation between progesterone concentration postpartum and time after delivery (r = -0.527; P = 0.036), but P = 0.744). There was no correlation between plasma progesterone or beta-endorphin and MAC by multiple regression (r = 0.166; P = 0.950). CONCLUSIONS: Isoflurane MAC remains 28% less than normal within the 1st 12 h postpartum and then returns to normal 12-25 h after delivery.

Adult↗
PubMed1995

Child pedestrian injuries in the Cape metropolitan area--final results of a hospital-based study.

Over a 12-month period 430 children under 14 years of age presented to Red Cross War Memorial Children's Hospital in Cape Town having been injured as pedestrians, and 106 children who died from such injuries were registered at the regional state mortuary. Information about the circumstances surrounding injury was obtained from the parents or guardians of all children reporting to hospital and 48 (45.3%) of the fatalities. Analysis of results revealed a strong relationship between pedestrian injury and children playing or running errands in residential areas during daylight hours, particularly in the later part of the afternoon. Only 24.3% of all children were supervised by an adult at the time of injury. The pattern of behaviour described must be acknowledged in the planning of future road safety measures. The inconsistency of parental supervision highlights the need to include adults in educational and awareness campaigns.

Accidents, Traffic↗
PubMed1994

Antepartum corticosteroids: disease stabilization in patients with the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP)

OBJECTIVE: Our purpose was to evaluate the impact of antepartum administration of corticosteroids on the course of the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP) in pregnancies at 24 to 37 weeks' gestation. STUDY DESIGN: This prospective, randomized study was undertaken in 25 antepartum patients with atypical severe preeclampsia expressed as HELLP syndrome. Twelve pregnant women were randomized to receive double-dose dexamethasone (10 mg intravenously every 12 hours) until delivery, and 13 women were randomized to the control arm. Management and delivery decisions for all patients were based on a common protocol, with delivery undertaken for a deteriorating maternal or fetal condition. RESULTS: In the corticosteroid-treated group the maternal platelet count significantly increased (p = 0.006), whereas lactic dehydrogenase and alanine aminotransferase significantly decreased over time (p = 0.03 and p = 0.005) in comparison to the 13 women who did not receive corticosteroids. Maternal urinary output after entry into the study was significantly increased within hours after steroid administration versus the control group (p = 0.0006). The study entry-to-delivery interval (41 +/- 15 hours) was significantly longer in the group of steroid-treated women (p = 0.0068). CONCLUSIONS: Stabilization and significant improvement in the laboratory and clinical parameters associated with HELLP syndrome occurred in women who received high-dose antenatal corticosteroids, as measured by maternal platelet count, urinary output, lactic dehydrogenase, alanine aminotransferase, and postponement of delivery. We believe the findings of this investigation permit us to speculate that this therapeutic approach could enhance maternal-fetal care by postponing delivery of some previable fetuses, reduce the need for maternal transfusion of blood products, reduce neonatal morbidity or mortality from multiple systemic effects, and facilitate a safer transfer of the ill mother to a tertiary care site for optimal peripartal care.

Adolescent↗
PubMed1994

Prognostic factor analysis of central nervous system relapse in adult acute lymphoblastic leukemia. A Southeastern Cancer Study Group report.

A randomized clinical trial in adult ALL has previously shown a benefit for central nervous system prophylaxis (intrathecal methotrexate plus cranial irradiation) with respect to CNS relapse-free interval, and the long-term follow-up revealed that about 20% of the patients in this multicenter trial were long survivors, probably cured. Questions that were not addressed in the earlier reports concern the time to CNS relapse as the initial site of relapse and the prognostic factors associated with initial CNS relapse. Further analysis of the 62 evaluable randomized patients has shown that in every case with CNS relapse, time to any relapse and time to CNS relapse as the first event were the same. Multivariate analysis showed that, although CNS prophylaxis is a significant favorable prognostic factor with respect to CNS relapse over time, race (nonwhite is unfavorable) and splenomegaly (unfavorable) are more significant, albeit not well explained. Future trials should examine race and splenomegaly as well as other clinical and biologic features as potential prognostic factors for CNS relapse in adult ALL.

Adolescent↗
PubMed1994

Management of brain metastases: past, present, and future.

Brain metastasis is an important cause of morbidity and mortality in cancer patients. Because most of these patients die of systemic disease, the primary therapeutic goal is to improve the quality of life. Conventional therapy for brain metastases is usually whole-brain irradiation. Chemotherapy often results in regression of brain metastases in chemosensitive tumors. We review our institutional experience in the treatment of brain metastasis with both radiation and chemotherapy. In the future, improvement in the management of brain metastases will depend on improved chemotherapy, radiosensitizers, and radiotherapy techniques such as stereotactic radiosurgery.

Adult↗
PubMed1993

Combination chemotherapy with or without thoracic radiotherapy in limited-stage small-cell lung cancer: a randomized trial of the Southeastern Cancer Study Group.

PURPOSE: The primary objective of this randomized prospective study was to compare the survival of limited-stage small-cell lung cancer (SCLC) patients treated with chemotherapy alone or chemotherapy plus thoracic radiotherapy (TRT). A secondary objective was to determine the effect of consolidation chemotherapy on survival. PATIENTS AND METHODS: This multiinstitutional phase III study included 386 patients with limited-stage SCLC. All patients received cyclophosphamide 1,000 mg/m2, doxorubicin 40 mg/m2, and vincristine 1 mg/m2 (CAV) every 3 weeks for six cycles. Irradiated patients received 30 Gy in 10 fractions during weeks 1 and 2 of chemotherapy. Fifteen Gy in five fractions was administered during week 7 (total dose, 45 Gy). Following CAV, responding patients were randomized to receive two cycles of consolidation chemotherapy (cisplatin 20 mg/m2/d for 4 days plus etoposide 100 mg/m2/d for 4 days) or observation. RESULTS: Complete (46% and 38%; P = .14) and overall response rates (67% and 64%; P = .58) were not statistically significantly different. Although not significantly different, median (14.4 v 12.8 months) and 2-year survival (33% v 23.5%) rates favored the irradiated patients. Grade 4 hematologic toxicity was greater in irradiated patients (60% and 39%; P < .001). Patients given consolidation chemotherapy experienced superior median (21.1 v 13.2 months; P = .028) and 2-year survival (44% v 26%; P = .028) rates. CONCLUSION: The concurrent use of TRT and CAV chemotherapy as administered in this study failed to improve the survival of limited-stage SCLC patients compared with CAV alone. Life-threatening hematologic toxicities were more frequent with combined-modality therapy. The survival of limited-stage patients treated with CAV (with or without TRT) was improved with two cycles of cisplatin and etoposide consolidation therapy. Whether similar survival results could be achieved with cisplatin and etoposide alone requires additional study.

Adult↗