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B Davidson

Publications and source records attributed to B Davidson.

At least 91 records · Page 5Linked to original sources
PubMed1997

Angiogenesis in uterine cervical intraepithelial neoplasia and squamous cell carcinoma: an immunohistochemical study.

Changes in vascular patterns aid in the colposcopic diagnosis of cervical neoplasia. We have studied vessels in 50 cases of normal cervix, cervical intraepithelial neoplasia (CIN I, II, III), and invasive carcinoma by two markers, Von-Willebrand factor (VWF) and ulex europaeus lectin I. With both markers, an increase in microvessel counts parallel to neoplastic progression was seen, with highest counts observed in CIN III. Average counts for ulex lectin and VWF increased from approximately 6 vessels per field in normal cervices to 15 vessels per field in CIN III. For each diagnostic group, comparable numbers of vessels were stained by both markers, with a slight preponderance of VWF in invasive carcinomas and of ulex lectin in noninvasive lesions. No correlation was found between microvessel count and human papilloma virus (HPV) by in situ hybridization. We conclude that enhanced microvessel density occurs in cervical neoplasia. The vessels are mostly blood vessels, not lymphatics. Therefore, the role of enhanced microvessel density in tumor spread remains to be proven.

Carcinoma, Squamous Cell↗
PubMed1997

An algorithm for pulmonary screening of military pilots in Israel.

BACKGROUND: Medical screening is used routinely to qualify and classify candidates for pilot training. The respiratory system assumes even greater importance owing to the increased stress of flying high-performance aircraft in a hostile environment characterized by high altitude, varying acceleration ("G" forces), and the possibility of rapid decompression. Any respiratory dysfunction may threaten the pilot's health, flight safety, and completion of the mission. Only those candidates with the highest psychophysical score are accepted to undergo special aeromedical screening. Physical suitability is an important factor in the selection and classification of candidates for flight training programs, and pulmonary function testing is central within this screening protocol. METHODS: We developed a respiratory algorithm for this unique screening process. The algorithm represents a practical and efficient approach for large-scale screening of healthy candidates for flight training. The algorithm deals with the major pulmonary health problems encountered in a previously screened healthy population aged 17 to 25 years. If by anamnesis, physical examination results, or baseline spirometry findings there is reason to suspect a respiratory problem that could emerge to endanger the pilot's life, a specially designed evaluation is performed according to the algorithm. We explain, step by step, the basis for each suggested test in order to reach a decision (operational specifications). The pulmonary function studies we recommend are reasonably priced and can be easily and reliably performed by regular medical staff technicians. The major justification for performing pulmonary function studies in a healthy population that has already gone through a preliminary medical screening and has been found fit is to identify occult or latent abnormalities. These abnormalities may have no or minimal clinical expression under ordinary circumstances but, under the stress of flight during the ensuing 5 to 10 years, may produce serious limitation in function. RESULTS: Two cases, seen in the Air Force Medical Center, are presented to illustrate how the algorithm is implemented. The algorithm has been in use for more than 5 years, and has been applied to the screening of several thousand candidates. Follow-up of the accepted candidates has not revealed any significant defects in the decision-making process. CONCLUSION: Use of the algorithm is highly cost-effective since it allows for nonspecialist physicians to carry out pulmonary screening and involves the pulmonary specialist only infrequently, ie, when a particularly complicated and/or borderline case is encountered. It is our contention that a similar algorithm would be useful in many other settings where large-scale screening is required.

Adolescent↗
PubMed1996

Monoclonal antibodies against eosinophils in liver allograft rejection.

There has been recent interest in eosinophils as a histological diagnostic marker of liver allograft rejection. However, the reliability of counting eosinophils in sections stained with hematoxylin and eosin (H&E) has not been evaluated previously. We quantified eosinophils in 10 day-5 protocol liver biopsy specimens in 10 patients. The control groups were 5 patients with cytomegalovirus infection, 5 patients with obscure liver dysfunction, and 6 patients with HCV infection. Eosinophil count was assessed using H&E and by specific monoclonal antibody staining using (1) an anti-ECP antibody (EG2) and (2) a monoclonal antibody against human eosinophil major basic protein (MBP) (BMK-13). The average percentage of the total inflammatory infiltrate of eosinophils in portal tracts was 9% in the moderate to severe rejection group as compared with 0.25% in the mild rejection group (P < .001) and 0% in the control group (P < .001). The eosinophil count decreased markedly after successful treatment of rejection. The H&E staining correlated with MBP+ the (BMK-13 immunoreactive) cells but were more numerous with BMK-13. BMK-13 also stained significantly more cells when compared with EG2 (P < .01). This difference may be because EG2 staining only activated eosinophils, whereas BMK-13 is a pan-eosinophilic maker, regardless of activation. This study confirms that eosinophils are a specific feature of acute cellular rejection and are an aid to its diagnosis. BMK-13 is a useful pan-eosinophilic marker that is more efficient in obtaining eosinophil count when compared with H&E.

Antibodies, Monoclonal↗
PubMed1996

Long-term immunosuppression without corticosteroids after orthotopic liver transplantation: a positive therapeutic aim.

Long-term treatment with corticosteroids after orthotopic liver transplantation (OLT) may cause adverse effects, particularly hypertension, diabetes, and bone disease. The results of steroid withdrawal from long-term immunosuppression in 114 patients after OLT was reviewed. Initial treatment was with corticosteroids, azathioprine, and cyclosporine A in 76.3% and with antithymocyte globulin in 17.5%. Corticosteroids were stopped in 96 patients (84.2%) during mean follow-up of 6.7 +/- 3.9 months, and acute rejection subsequently developed in 8. By comparison 7 of 18 patients, in whom corticosteroids were continued, developed acute rejection. Six of these had received blood group (ABO)-compatible nonidentical grafts. Rates for retransplantation in the steroid withdrawal and nonwithdrawal groups were 4.2% and 22.2%, respectively, and mortality in the two groups was 14.6% and 44.4%, respectively. Azathioprine was not given or withdrawn in 28 patients in the group from which corticosteroids were also withdrawn, with no adverse effect. Diabetes mellitus improved following corticosteroid withdrawal, but there was no improvement in hypertension. We conclude that corticosteroids can be safely withdrawn in the majority of patients after OLT.

Adrenal Cortex Hormones↗
PubMed1996

The effect of anesthesia type on needle localization breast biopsy: another point of view.

BACKGROUND: Efforts directed at early detection of breast cancer have resulted in an increased incidence of nonpalpable mammographic lesions that warrant excisional biopsy. The most common localization method is by use of the hook wire technique, or needle localization biopsy. Although much has been written about the localization technique, the impact of the method of anesthesia on the accuracy of the biopsy and especially on the completeness of the excision has not been clarified. PATIENTS AND METHODS: We studied 450 needle localization breast biopsies to determine whether the type of anesthesia (local versus general) influenced the accuracy and completeness of the biopsy. We compared 153 biopsies performed under local anesthesia to 297 done under general anesthesia. RESULTS: The use of local versus general anesthesia did not affect accuracy; however, it did determine the inability to achieve clean margins (27.6% versus 7.3%, respectively, P <0.02). It was more difficult to excise completely specimens located deeper than 3 cm in the breast, when the localizing needle travelled more than 3 cm, and when the lesions were of the microcalcification mammographic pattern. CONCLUSIONS: For lesions mammographically suspicious for malignancy, mainly those located deeper than 3 cm, general anesthesia is preferred.

Anesthesia, General↗
PubMed1996

Regional hyperthermic perfusion with cisplatin following surgery for malignant melanoma of the extremities.

BACKGROUND: The study was undertaken to review our experience in the treatment of extremity melanoma with hyperthermic isolated limb perfusion (HILP), using cisplatin as the chemotherapeutic agent. We also evaluated the best timing for regional lymph node dissection in relation to the perfusion. PATIENTS AND METHODS: Sixty patients with advanced malignant melanoma of the limbs were treated with HILP used mainly as an adjuvant treatment. There were 56 lower- and 4 upper-limb HILPs. Cisplatin was used at a dose of 20 mg/L of limb volume. Temperature at the tumor site was 39 degrees C to 40 degrees C. Postoperative complications, disease-free period, and time to recurrence were recorded. RESULTS: There were no deaths related to the procedure. Forty-seven percent of the patients developed local complications; most complications were minor and resolved within 60 days. The local complication rate was higher when HILP was performed shortly after or simultaneously with regional lymph node dissection. None of the patients had systemic complications. Mean survival time from treatment was 87.2 months. Currently, 35 patients (58%) are alive and free of disease 52.7 +/- 22.5 months after HILP. Twelve patients (20%) are alive with recurrent disease, of which 5 recurred locally. The average time (+/- standard error of the mean) to recurrence was 24.5 +/- 13.8 months after perfusion. CONCLUSIONS: HILP with cisplatin is a relatively safe procedure, which seems to increase locoregional control of advanced malignant melanoma of the extremity. Separating the timing of lymph node dissection from HILP by 6 to 8 weeks reduces the complication rate.

Aged↗
PubMed1996

Liver biopsy in liver transplantation: no additional risk of infections in patients with choledochojejunostomy.

BACKGROUND/AIMS: This study aimed to determine whether there is an increased infectious risk following liver biopsy in liver transplant patients with choledochojejunostomy. METHODS: We evaluated the incidence of liver-biopsy-related sepsis in a consecutive series of 27 patients who underwent choledochojejunostomy, either during the transplant procedure (17 patients) or later following biliary complications (10 patients). We evaluated another 138 patients as a control group who had orthotopic liver transplantation during the same period and underwent duct-to-duct anastomosis. All liver biopsies had routine, prior ultrasound evaluation to detect dilated biliary ducts. RESULTS: In the 27 patients who underwent choledochojejunostomy, 96 liver biopsies were performed: the sepsis rate was 3.12% per biopsy (n = 96) or 7.4% per patient (n = 27). However, despite a normal ultrasound, subsequent ERCP demonstrated biliary obstruction in one patient. Thus the rate of sepsis was 2.1% per biopsy or 3.7 per patient. In the control group 338 liver biopsies were performed: the sepsis rate was 1.5% per biopsy (n = 338) or 2.9% per patient (n = 138). The difference was not significant. All septic episodes had positive blood cultures for a single enteric microorganism, and all responded to antibiotics CONCLUSIONS: Our data do not suggest that liver-transplanted patients with choledochojejunostomy are more at risk of sepsis following liver biopsy, providing there is no "occult" biliary obstruction; therefore, they do not require prophylactic antibiotics as has been suggested by other authors.

Adolescent↗
PubMed1996

Endoscopic retrograde cholangiography in the diagnosis and endoscopic management of biliary complications after liver transplantation.

OBJECTIVE: Biliary reconstruction in orthotopic liver transplantation is increasingly being performed without T tube drainage. This increases the difficulty of diagnosing subsequent biliary tract problems, with a greater reliance placed on endoscopic retrograde cholangiopancreatography (ERCP) for the diagnosis of biliary tract complications. The usefulness of ERCP was evaluated in patients who underwent liver transplant where biliary reconstruction was not done with T tube drainage. DESIGN AND PARTICIPANTS: A retrospective study of the case notes of 90 patients who underwent liver transplantation, and in whom the biliary reconstruction was by end to end choledochocholedochostomy without T tube splintage. RESULTS: ERCP was performed as the primary procedure to investigate a suspected biliary complication in 30 patients (33%). The procedure was successful in 26 patients (87%), and showed a biliary stricture in 12 patients and a bile leak in six patients. ERCP was normal in seven patients and demonstrated dilated ducts alone in one patient. Six of the biliary strictures were successfully dilated endoscopically (50%), but none of the bile leaks resolved with endoscopic drainage. CONCLUSION: This study confirms the diagnostic role of ERCP post liver transplant. The therapeutic role requires clearer evaluation with a controlled trial.

Adolescent↗
PubMed1996

Treatment of acute gastroenteritis: too much and too little care.

This paper reviews the health services literature regarding care for gastroenteritis in children. United States health care utilization, use of oral rehydration therapy (ORT), and quality of care considerations are described. The literature suggests that some US children may receive too much care while others may not be getting enough and that physician practices continue to differ from expert recommendations.

Acute Disease↗
PubMed1996

Efficacy of glucose-based oral rehydration therapy.

OBJECTIVE: This article reviews and synthesizes evidence in the published literature on the safety and efficacy of oral rehydration therapy (ORT) among young children with pediatric gastroenteritis in developed nations. METHODOLOGY: We searched the literature for randomized, controlled trials comparing the safety and efficacy of ORT with intravenous (IV) rehydration treatment and/or oral rehydration solutions (ORSs) of different sodium content. We combined the failure rates of each set of studies in statistical meta-analyses and conducted tests of homogeneity of treatment effect over all the studies and for subgroups of children defined by the trial type, the sodium content of the ORS, and the setting of care. We also conducted a multivariate logistic regression on the probability of failure to determine the relative importance of these factors, controlling for other characteristics of the trials. Other outcomes were also tabulated and discussed. These include the relative incidence of hypernatremia and hyponatremia induced by treatment; weight gain; the volume, frequency, and duration of diarrhea; for inpatient trials, the length of stay; and for outpatient trials, rates of hospitalization. RESULTS: The evidence suggests that among pediatric patients with gastroenteritis in developed countries, failure of ORT, defined as the need to rehydrate children intravenously, is infrequent. We found a combined overall ORT failure rate of 3.6%. We found no statistically significant difference in failure rates by trial type or the sodium content of the ORS. However, we did find some supporting evidence for a lower failure rate among children treated in outpatient settings. In addition, compared with patients rehydrated intravenously, pediatric patients treated with ORT were not found to be at higher risk of iatrogenic hypernatremia or hyponatremia. The evidence from the literature fails to show a consistent trend in favor of either high- or low-sodium solutions for rehydration of pediatric patients. CONCLUSIONS: There seems to be a great potential for improving the medical treatment of children with acute gastroenteritis by the greater use of ORT.

Adolescent↗
PubMed1996

Acute Budd-Chiari syndrome treated by liver transplantation in a woman homozygous for factor V Leiden.

We describe the first case of Budd-Chiari syndrome due to homozygosity for factor V Leiden resulting in resistance to activated protein C. This is now recognized as the most common procoagulant disorder, and may account for many cases of Budd-Chiari syndrome previously though to be idiopathic or due to a latent myeloproliferative disorder. A further unique feature of this case is that the patient required orthotopic liver transplantation following failure of portacaval shunting and progressive hepatic necrosis. We demonstrated that liver transplantation resulted in correction of the serum coagulation abnormality; however, it is unlikely to have cured the disorder as platelet factor V would still be of the Leiden phenotype.

Acute Disease↗
PubMed1995

A recombinant bcl-x s adenovirus selectively induces apoptosis in cancer cells but not in normal bone marrow cells.

Many cancers overexpress a member of the bcl-2 family of inhibitors of apoptosis. To determine the role of these proteins in maintaining cancer cell viability, an adenovirus vector that expresses bcl-xs, a functional inhibitor of these proteins, was constructed. Even in the absence of an exogenous apoptotic signal such as x-irradiation, this virus specifically and efficiently kills carcinoma cells arising from multiple organs including breast, colon, stomach, and neuroblasts. In contrast, normal hematopoietic progenitor cells and primitive cells capable of repopulating severe combined immunodeficient mice were refractory to killing by the bcl-xs adenovirus. These results suggest that Bcl-2 family members are required for survival of cancer cells derived from solid tissues. The bcl-xs adenovirus vector may prove useful in killing cancer cells contaminating the bone marrow of patients undergoing autologous bone marrow transplantation.

Adenoviruses, Human↗
PubMed1994

Total abdominal perfusion (TAP) in the treatment of abdominal metastatic melanoma.

Total abdominal perfusion (TAP) is a recently described technique in which the abdominal organs are isolated from the systemic circulation and perfused by means of an external pump. Administering chemotherapy into the circuit provides higher locoregional drug exposure with lower systemic toxicity. Two patients with melanoma metastatic to the abdomen were treated using this technique. The first patient suffered from intractable upper gastrointestinal bleeding due to unresectable melanoma metastasis of the duodenum. He underwent TAP with melphalan and cisplatinum. His bleeding stopped and the tumor regressed. The patient's response lasted for 6 months. The second patient had an unresectable liver metastasis. She underwent TAP with melphalan and DTIC, resulting in a complete response with disappearance of the liver mass, which lasted until her death in 13 months. Our conclusion is that TAP should be considered as a technique for regional chemotherapy, which may be used in the treatment of unresectable metastatic melanoma of the abdomen.

Abdominal Neoplasms↗