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Biomedical subjects

B Kaplan

Publications and source records attributed to B Kaplan.

At least 19 recordsLinked to original sources
PubMed1992

Isolation and purification of amyloid protein A by sodium dodecyl sulphate polyacrylamide gel electrophoresis and reversed-phase high-performance liquid chromatography.

Sodium dodecyl sulphate polyacrylamide gel electrophoresis and reversed-phase high-performance liquid chromatography (HPLC) were used consecutively for the isolation of amyloid protein A (protein AA) from amyloid fibrils. Highly purified protein AA was obtained and determined by electrophoretic and amino acid analyses. The heterogeneity of protein AA was shown by HPLC. The isoforms of protein AA had different hydrophobicities, although they were equal in size and similar in amino acid composition. Compared with the conventional amyloid separation procedure (gel permeation chromatography), this technique is rapid, requires only small amounts of amyloid fibrils and may provide new information on amyloid proteins.

Amino Acids↗
PubMed1992

Effect of EGF on the corneal wound healing of alloxan diabetic mice.

We identified the local treatment effect of epidermal growth factor on corneal wound healing of alloxan diabetic mice. The corneal wounds were induced by 0.5 M NaOH solution on the corneal surfaces of the diabetic and non-diabetic groups. The local epidermal growth factor solution (100 ng ml-1) was dropped in 5-microliters aliquots into the eye twice a day. The corneal wounds were measured daily for 15 days and examined histologically at the end of 15th day of experimental period. The results indicated that topical epidermal growth factor treatment of diabetic and non-diabetic mice greatly improved the incidence of healing of wounded corneas.

Administration, Topical↗
PubMed1992

Human papillomavirus types and cervical squamous intraepithelial lesions that recur after cold-knife conization.

The purpose of this study was to analyze the HPV types and histological margins of cervical squamous intraepithelial lesions (SILs) treated by cold-knife conization and to correlate this with recurrent disease. Of 203 cone biopsies done for SILs primarily because the entire lesion could not be visualized at colposcopy, follow-up information was available for 85 cases. Of these 85 cases, biopsy-proven recurrences were documented for 10 (12%) women. In the SILs which recurred after conization, the lesion was noted on the surgical margin in 7/10 (70%) cases. In contrast, SILs that did not recur after cold-knife conization were detected on the surgical margin in only 12% of cases. In 7 of the recurrences, the HPV type detected in the pretreatment SIL was the same as that detected in the SIL that occurred after conization. In the other 3 recurrences, one of either the primary or recurrent SILs was HPV positive and the other corresponding lesion HPV negative. It is concluded that detection of a SIL on the surgical margin is a marker for recurrent disease and that recurrences are often associated with the same HPV type as that noted in the pretreatment SIL.

Biopsy↗
PubMed1992

Treatment of pyoderma gangrenosum with clofazimine.

We report a case of pyoderma gangrenosum in a 80-year-old woman suffering from ulcerative colitis and treated with clofazimine. Significant improvement was evident within 5 days following commencement of therapy, complete healing occurred after only 4 weeks of treatment.

Aged↗
PubMed1992

On the mechanism of impaired distal acidification in hyperkalemic renal tubular acidosis: evaluation with amiloride and bumetanide.

It has been postulated that a distinctive type of hyperkalemic distal renal tubular acidosis (DRTA), referred to as voltage-dependent DRTA, results from diminished potassium and hydrogen ion secretion in the distal nephron, which is due to a suboptimal voltage (lumen negative) as a result of impaired sodium reabsorption. To test for the presence of a voltage-dependent DRTA, we used amiloride (20 mg oral, single dose) and bumetanide (2 mg oral, single dose) to inhibit and to stimulate voltage-dependent potassium and hydrogen ion secretion, respectively. Eighteen patients with hyperkalemic DRTA and seven controls with a comparable degree of renal impairment were studied. Patients were subdivided in two groups on the basis of their ability to lower their urine pH during spontaneous acidosis. Patients in Group I lowered their urine pH to the level of controls (5.29 +/- 0.06 and 5.37 +/- 0.11, respectively) whereas patients in Group II could not lower their urine pH below 5.5 (6.38 +/- 0.11). Patients in Group I and Group II had a similar degree of metabolic acidosis and hyperkalemia whereas controls had neither acidosis or hyperkalemia. Most patients in Group II and all patients in Group I had low plasma aldosterone levels. The administration of amiloride resulted in an increase in urine pH and a decrease in potassium excretion in all three groups. The finding that amiloride, presumably by obliterating the transtubular voltage as a result of blockade of sodium transport, inhibited potassium excretion to about the same extent in both groups of patients and in controls argues against the existence of a voltage-dependent defect. Bumetanide produced a fall in urine pH below 5.5 and an increase in potassium excretion in controls and Group I patients. In Group II patients, bumetanide failed to elicit a fall in urine pH below 5.5 but resulted in an increase in potassium excretion similar to that seen in controls and Group I patients. These findings suggest that a derangement other than a voltage-dependent defect is responsible for the inability, characteristic of Group II patients, to lower their urine pH. It was concluded that the impairment in urinary acidification observed in patients with this subtype of hyperkalemic DRTA is due to a defect in collecting tubule hydrogen secretion that results from H+ ATPase dysfunction rather than from a voltage-dependent defect.

Acidosis, Renal Tubular↗
PubMed1992

Enhanced urinary albumin excretion after 35 weeks of gestation and during labour in normal pregnancy.

This study reports on the urinary albumin to creatinine ratio during normal pregnancy, with special emphasis on the pre-delivery and labour periods. Albumin was determined in single voided urine specimens obtained from healthy non-pregnant women (n = 16) and healthy pregnant women (n = 203; Groups A and B, 133 females examined during clinic visits and presentation at obstetric department; Group C, 70 females examined during labour) by radioimmunoassay (RIA). The mean ratio (+/- SD) for albumin/creatinine (A/Cr) in non-pregnant women was 1.46 +/- 0.32 mg mmol-1 Cr. Thus, 2.10 mg mmol-1 Cr (mean+2 SD) was considered to be the upper limit of normo-albuminuria. During pregnancy, 73% of the women (97 out of 133, Groups A and B) excreted less than or equal to 2.10 mg mmol-1 Cr. During the first 35 weeks of gestation, 30 of 34 pregnant women (88%) excreted less than or equal to 2.10 mg mmol-1 Cr, the mean being 0.93 +/- 0.64 mg mmol-1 Cr (median 1.0 mg mmol-1). During 36-42 weeks of gestation, the median A/Cr was 1.93 mg mmol-1 Cr (range 0.43-12.16) and 32 of 99 (32%) had values greater than 2.10 mg mmol-1 Cr, an increase of more than two-fold (p less than 0.031) compared with the first 35 weeks. During labour, 61% of non-haematuric urines (33 of 54, Group C) were greater than 2.10 mg mmol-1 Cr, being 125% greater (p less than 0.006) than that observed during pregnancy. Thus in normal pregnancy, A/Cr is increased during the late period of pregnancy and during labour.

Adolescent↗
PubMed1992

Clinical and laboratory work-up prior to hormone replacement therapy in postmenopausal women.

In a retrospective study on 100 female patients (mean age 52 years), with a menopause lasting for 3.5 years, referred to the Menopausal Clinic of Beilinson Medical Center, we studied the pretreatment, clinical and laboratory work-up before administration of hormone replacement therapy (HRT). The work-up consisted of clinical and medical examination and history. Mammography is a necessary test for malignancy exclusion, and also the assessment of lipid metabolism. Pap smear is not so important since cervical cancer is a rare event in Jewish women and pelvic sonography cannot be a decisive diagnostic tool for ruling out malignancy. We conclude that HRT for prevention of osteoporosis and cardiovascular disease should be administered in a menopausal clinic by a gynecologist, after performing a few tests: confirmation of menopause by follicle-stimulation hormone (FSH) and E2, excluding malignancy by mammography, and confirmation of normal lipid metabolism.

Clinical Protocols↗
PubMed1992

[Intrauterine device, the best method for spacing births in breastfeeding mothers].

Twenty-nine breastfeeding women, with a mean age of 36.5 years, were fitted with an IUD, Nova T or Multi load 375, at an average time of 3.6 months after delivery. Insertion at this time was easy, without dilatation, pain or bleeding. During a follow up of 18 months, the IUD has to be discontinued in one woman (3.4%) because of excessive menstrual bleeding, at a time when she was no more fully breastfeeding. The continuation rate was 96.56%, as compared to only 82% for a general population of 216 women fitted with IUD at the same period after delivery and followed up for the same period of time. The IUD is in our opinion the birthspacing method of choice for breastfeeding mothers.

Adult↗
PubMed1992

Response to head-up tilt in cramping and noncramping hemodialysis patients.

Hemodialysis-associated skeletal muscle cramps are generally ascribed to a reduction in plasma volume, but during this procedure, it is not known how volume contraction results in cramps. To elucidate this mechanism, we compared responses to one hour of 60 degrees head-up tilt in 8 patients who cramped during no more than one-sixth of their dialyses and in 8 patients who cramped at least half the time. Age and recumbent blood pressure were similar in each group, but more patients with frequent cramps had diabetes underlying their renal failure (p = 0.013) and had been dialyzed for less than 3 years (p = 0.020). Baseline plasma renin activity and plasma norepinephrine and arginine vasopressin concentrations were similar in both groups, except plasma renin activity in one patient with frequent cramps, which was 15 times higher than in the other patients. After tilting, systolic blood pressure fell an average of 17% in patients who cramped infrequently (p = 0.0031) but only 10% in frequently cramping patients. The ratio of tilt/recumbent norepinephrine levels exceeded 1.5 in 7 patients with frequent cramps but was less than this in 6 patients who cramped infrequently (p = 0.020). One of the 2 infrequently cramping patients with a ratio above 1.5 was the only individual to have a normal renin response to tilt. We propose that cramps are prone to occur during hemodialysis in patients whose sympathetic nervous system response to volume stress is partially intact but is not modulated by concurrent activation of the renin-angiotensin system.

Adult↗
PubMed1992

The bone sparing effect of oral contraceptive use in non-smoking women.

In a group of 30 women, mean age 23.7 years, we have examined the urinary calcium: creatinine ratio (Ca:Cr) as an indicator of bone resorption, before and 6.8 months after oral contraceptive (OC) use. Fasting Ca:Cr decreased significantly during OC use, being more pronounced in nonsmokers. We agree with those who propose the use of OC in women also after 35 years of age, in view of their good effect on bone density.

Adolescent↗
PubMed1991

Primary central nervous system lymphoma in acquired immune deficiency syndrome. A clinical and pathologic study with results of treatment with radiation.

Primary central nervous system (CNS) lymphoma occurs frequently in patients with the acquired immune deficiency syndrome (AIDS). Seventeen patients with AIDS and biopsy-proven CNS lymphoma were treated with whole-brain radiation. At presentation, most patients were severely debilitated from previous AIDS-related illnesses. Patients generally had focal neurologic symptoms such as seizures and paralysis. Headaches and mental status changes, often noticed after hospital admission, seldom brought our patients to seek medical attention. Computed tomography (CT) scan showed low-density, contrast-enhancing, mass lesions with variable amounts of peritumor edema. Size, location, and pattern of contrast enhancement of the lesions varied. No specific pattern was seen that could be used to distinguish between CNS lymphoma, toxoplasmosis, or other CNS diseases that occur in patients with AIDS. Biopsy results showed angiocentric, high-grade, large cell tumors with frequent necrosis. Immunohistochemical analysis showed B-cell phenotype with small amounts of T-cells, presumably reactive. All patients received irradiation to the whole brain with parallel opposed fields. A variety of doses and treatment regimens were used. Mean survival was only 72 days. Survival was longer in patients with higher pretreatment Karnofsky scores. The correlation between dose and survival was not significant. At completion of therapy, most patients showed improvement in Karnofsky score and had partial improvement in neurologic symptoms. CNS lymphomas in patients with AIDS are responsive to radiation. Posttreatment CT scans showed regression of tumors. Autopsy examinations showed regression of tumors, but also showed concurrent CNS infections, AIDS encephalopathy, and radiation-induced changes within the normal CNS tissue. Opportunistic infections rather than cerebral herniation or uncontrolled lymphoma was the most common cause of death.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Separation of proteins by consecutive sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and reversed phase high performance liquid chromatography.

A procedure for the preparative separation of proteins was developed by using consecutively sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) and reversed phase high performance liquid chromatography (HPLC). The proteins were separated by SDS-PAGE and afterwards extracted from the gel. The extracted proteins were separated from SDS and other small molecular weight contaminants on a Fractogel TSK HW-40 (F) column in acidic aqueous acetonitrile. The proteins eluted from the Fractogel column were fractionated by HPLC. The identity and purity of the recovered proteins was confirmed by SDS-PAGE analysis.

Chromatography, Gel↗