Search PubMed⌕ Search

Biomedical subjects

A Berman

Publications and source records attributed to A Berman.

At least 55 records · Page 3Linked to original sources
PubMed1995

Bone mineral density in a native population of Argentina with low calcium intake.

OBJECTIVE: To determine the bone mineral density (BMD) of a group of natives from Tafi del Valle, Argentina, to examine possible differences compared to other populations. METHODS: BMD of lumbar spine and proximal femur was evaluated by dual x-ray absorptiometry (DEXA), in volunteer natives of El Potrerillo y El Rincon (descendants of the Amaichas and Quilmes). Forty-seven women and 31 men between 20 and 80 years of age were assessed. Average daily intake of calcium, physical activity level, serum levels of 25-OH vitamin D (25-OH-D), calcium, phosphorus and alkaline phosphatase were also determined. RESULTS: Average calcium intake was 345 +/- 22.4 mg/day (mean +/- SD). The average sunlight exposure was 3.8 +/- 0.44 h. Degree of physical activity was moderate/hard (grade 4) to very hard (grade 6) in those 60 yrs of age or younger. Laboratory values were normal except for 25-OH-D levels, which were significantly greater in Tafi del Valle (26.8 ng/ml) than in Buenos Aires (20.7 ng/ml); (p < 0.05) BMD of the proximal femur of both sexes was significantly greater compared to the reference groups; Z score of the female population was femoral neck: +/- 0.64 (p < 0.05); Ward's triangle: +/- 0.64 (p < 0.001); trochanter: +/- 0.90 (p < 0.001). Among men, femoral neck: +/- 0.53 (p < 0.01); Ward's triangle: +/- 1.45 (p < 0.001); trochanter: +/- 0.95 (p < 0.001). No significant differences were observed in the lumbar spine BMD. The high physical activity required by the mountainous land of Tafi del Valle may be the cause of increased BMD at the proximal femur among these people. High values of vitamin D produced by increased sun exposure can lead to greater absorption of calcium despite low calcium intake. CONCLUSION: Greater physical activity, higher levels of vitamin D, and racial factors in the native population could explain the greater BMD seen in the proximal femur despite low calcium intake.

Absorptiometry, Photon↗
PubMed1994

Photoaffinity labelling of Plasmodium falciparum proteins involved in phospholipid transport.

Erythrocytes infected with mature-stage malaria parasites accumulate phospholipids from exogenous sources. We show that the transport of N-(7-nitrobenzy-2-oxa-1,3-diazol-4-yl)-1,2- dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (N-NBD-DPPE), from the erythrocyte membrane to the intracellular malaria parasite, is dependent upon metabolic energy. A photoreactive phospholipid analogue, N-[125I]iodo-4-azidosalicylamidyl-1, 2-dilauryl-sn-glycero-3-phosphatidylethanolamine (N-125I-ASA-DLPE), has been synthesised and used in an attempt to identify proteins involved in phospholipid trafficking in malaria-infected erythrocytes. This photoreactive probe was found to preferentially label a protein with an apparent molecular weight of 22 kDa. Photolabelling of the 22-kDa protein was enhanced upon ATP depletion of malaria-infected erythrocytes.

Adenosine Triphosphate↗
PubMed1994

Diurnal fluctuations in plasma ions and water intake of dairy cows as affected by lactation in warm weather.

The presumption that water, Na, K, and Cl homeostasis is affected by the initiation of lactation, especially in hot weather, was examined. The study was conducted using five Israel Holstein cows at 1 to 2 wk before parturition (period 1) and at 2 wk (initiation of lactation) and 7 wk (established lactation) postpartum (periods 2 and 3, respectively). In period 1, most water intake was related to feed (in the absence of overt Na or osmotic stimuli). In contrast, during lactation, drinking was probably a combined response to feed-related and hypertonicity stimuli. Diurnal fluctuations in plasma ions, frequency of drinking, and volume ingested at each drinking increased postpartum. In period 2, plasma ion concentrations still were regulated around mean values, which was not the case in period 3, during which large diurnal variation in mean values occurred. The lowest values and highest variabilities were recorded in period 3 at midday. With the transition from the dry period to lactation, plasma concentrations of Na and Cl were reduced and became more labile, but the relationships between them remained stable. Plasma K seemed to vary independently of the two other ions. The reduced homeostatic efficiency of plasma ions during early and established lactation in hot weather may have consisted of an accumulation of their deficiencies, enhanced excretion of K in sweat, and sequestration of Na and Cl in the rumen.

Animals↗
PubMed1993

Adhesion of mouse hepatocytes to type I collagen: role of supramolecular forms and effect of proteolytic degradation.

Mouse hepatocytes were found to adhere much stronger to intact native type I collagen than to native, telopeptide-devoid collagen. Removal of telopeptides (by pepsin treatment) caused disintegration of supramolecular collagen aggregates. Similar differences in hepatocyte adhesion were observed between oligomeric and monomeric collagens separated from intact native preparations. It was concluded that the more active cell binding to intact collagen is due to a higher binding affinity of hepatocytes to supramolecular (oligomeric) forms of type I collagen. Heat denturation did not affect cell adhesion to intact collagen but restored adhesion to telopeptide-devoid substrates. Cell adhesion to denatured collagen was RGD-dependent whereas adhesion to native substrates proved RGD-independent. These data provide the first evidence of the role of supramolecular arrangement and the effect of proteolytic degradation of type I collagen on its adhesive behavior.

Amino Acid Sequence↗
PubMed1993

Cytoreductive surgery prior to interleukin-2-based therapy in patients with metastatic renal cell carcinoma.

From May 1985 to December 1990, 93 patients with the clinical diagnosis of metastatic renal cell carcinoma and their primary tumor in place were evaluated for cytoreductive surgery as preparation for systemic therapy with regimens based on interleukin-2. These patients had typical sites of metastatic disease and manifestations of paraneoplastic syndromes. Patients underwent removal of the primary tumor, as well as debulking when this could be performed safely. Thirty-two percent of patients (30/93) had a second surgical resection in addition to their nephrectomy, frequently because of the large size of the primary tumor and its invasion of adjacent structures. Thirteen percent of patients (12/93) experienced postoperative complications. There were no perioperative mortalities. Forty percent of patients (37/93) who underwent nephrectomy could not be treated with immunotherapy, usually because of progression of disease. A preoperative ECOG status greater than or equal to 2 was the only significant risk factor associated with failure to undergo immunotherapy (P = 0.043). The response rate to immunotherapy in the 56 patients receiving interleukin-2 was 27 percent (4 CR, 11 PR).

Adolescent↗
PubMed1993

Suicidality in hospitalized adolescents: relationship to prior abuse.

The effects of admission status, prior abuse, and the frequency and duration of both physical and sexual abuse on measures of suicidality for a sample of 117 hospitalized adolescents were investigated. Having been abused was found to have a significant association with the number of previous suicide attempts and to interact with the variable of admission status in measures of suicide ideation.

Adolescent↗
PubMed1993

A mathematical model of oscillatory insulin secretion.

Insulin is secreted in sustained oscillatory fashion from isolated islets of Langerhans. This finding has led to the assumption of an underlying synchronizing process that coordinates insulin oscillations. This assumption was tested by developing a mathematical model of oscillatory insulin secretion in which we included degree of synchrony as a parameter. We first evaluated insulin oscillations in perifused isolated rat islets, using spectral analysis to determine their regularity and frequency. A parsimonious mathematical model was developed to account for these characteristics. The model postulates a group of secretory units discharging at discrete intervals with the same underlying period. Variation from two sources, phase differences between units (synchrony) and regularity within units, is introduced by adding two normally distributed random variables with standard deviations (Sg and Si, respectively) to the secretory period. Sets of 100 simulations for different values of Sg and Si were run. Results of the simulations suggest that the system tolerates a relatively large degree of asynchrony yet still demonstrates regularity of oscillations on spectral analysis. Comparison with perifusion data suggests that a moderate degree of asynchrony between islets can best account for the pattern of insulin oscillations observed. This model provides a theoretical basis for the study of mechanisms for insulin oscillations.

Adenoma↗
PubMed1993

Effect of heat stress on tonic and GnRH-induced gonadotrophin secretion in relation to concentration of oestradiol in plasma of cyclic cows.

Effects of acute and seasonal heat stress on tonic and GnRH-induced LH and FSH secretion were examined during the early follicular phase of the oestrous cycle of cows (n = 40). Prostaglandin F2 alpha was injected on day 11 +/- 1 of the oestrous cycle and on the next day blood samples were collected at intervals of 15-20 min for 14 h, and i.m. injection of GnRH was given after 7 h. Treatments compared were control versus acute heat stress during blood sampling in winter, and cooled versus chronic heat stress in summer. Before GnRH injection, chronic heat stress in summer did not affect basal concentrations of plasma LH, but did lower LH pulse amplitude. However, in cows with low plasma oestradiol (1.9 +/- 0.2 pg ml-1), the mean and basal concentrations and amplitude of tonic LH pulses were reduced by heat stress (3.1, 2.1 and 4.8 versus 1.9, 1.4 and 2.5 ng ml-1, respectively). In cows with high plasma oestradiol (6.3 +/- 0.5 pg ml-1), these parameters were not affected. In chronically heat stressed cows in summer, GnRH-induced increases in plasma LH and FSH concentrations were the same as in the cooled controls. However, in cows with low plasma oestradiol, mean concentrations of FSH in plasma (31.8 versus 25.5 ng ml-1), the peak of the GnRH-induced FSH and LH surge (FSH 47.4 versus 35.6 ng ml-1, LH 50.7 versus 37.3 ng ml-1) and the shape of the GnRH-induced FSH and LH curves (treatment by time interaction) were significantly lower in non-cooled versus cooled controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The urological manifestations of chronic granulomatous disease.

Chronic granulomatous disease is a rare disorder of phagocytic cell oxidative metabolism. Patients have recurrent infections with catalase positive organisms and granulomatous lesions throughout the body. The genitourinary tract can be an occult site of involvement. We reviewed the prevalence of urological abnormalities in 60 patients with chronic granulomatous disease. Chart review revealed that 23 of the 60 patients (38%) had urological manifestations. Seven patients had 10 ureteral strictures. Treatment of the granulomatous strictures with steroids caused at least a temporary decrease in size or a resolution of the granulomas and strictures with steroids caused at least a temporary decrease in size or a resolution of the granulomas and relief of the obstruction. Three patients had bladder granulomas and 1 had a urethral stricture. A total of 12 patients had urinary tract infections and 7 had altered renal function. Ten patients had other manifestations of genitourinary disease. Abnormalities in the urinary tract are relatively frequent. Risk factors include X-linked disease and low percentile weight. Genitourinary manifestations can cause significant morbidity in chronic granulomatous disease patients. A variety of therapies, including judicious use of steroids and gamma-interferon, are proving to be useful in the treatment of this disorder and in some cases they may offer a nonoperative alternative for relief of chronic granulomatous obstructive disease in these patients.

Female↗
PubMed1992

Chronic idiopathic hyperphosphatasia. Report of a case treated with pamidronate and a review of the literature.

We describe the case of a 38-year-old woman with 24 years of progressive skeletal deformities. Radiologic survey showed evidence of generalized skeletal involvement. She presented with secondary osteoarthritis, and her hands showed Heberden's and Bouchard's nodes. Light microscopic examination showed many reversed lines in the trabeculae and increased bone resorption and bone forming areas. On electron microscopic study there were intranuclear inclusions in the osteoclasts. To our knowledge, she is the oldest patient described in the English literature, and the first treated with (3-amino-1-hydroxypropilidene)-1,1 biphosphonate (Pamidronate). She showed a decrease in serum alkaline phosphatase, urinary hydroxyproline. Clinical variables showed good response to medication.

Adult↗
PubMed1991

Water, sodium, potassium, and chlorine metabolism of dairy cows at the onset of lactation in hot weather.

Water, Na, K, and Cl balances, blood plasma composition, and urine and fecal outputs were studied in 5 high yielding cows (greater than 30 kg/d milk) at 2 wk prepartum and at 2 and 7 wk postpartum during the summer in Israel. Cows were fed complete diets with electrolyte content exceeding dietary recommendations. Plasma volume, as assessed by hematocrit changes, was greater postpartum, probably due to increased heat load and water turnover. Milk secretion markedly increased electrolyte output, which was compensated for only partially by increased intake. This was associated with marked reduction of electrolyte losses in excreta, particularly that of Na and Cl. On the basis of urea excreted in the urine, it seems that the current practice of abruptly increasing protein content of the diet at the onset of lactation might reduce the efficiency of dietary protein utilization, compared with efficiency of protein utilization at a later stage of lactation. The need to excrete excessive N also adversely affected the water and electrolyte balances. At initiation of lactation, when DMI is still limited and hot weather obstructs its rapid increase, the current recommendations for electrolytes as a percentage of the ration do not meet the needs.

Animals↗
PubMed1991

Rheumatic manifestations in populations at risk for HIV infection: the added effect of HIV.

We assessed the frequency and variability of rheumatologic manifestations in 2 populations with similar risk factors for human immunodeficiency virus (HIV) infection, of which only one was affected. We studied 2 populations at risk for HIV infection (homosexual and intravenous drug users). Group A: 89 individuals carried the virus; and Group B: 80 individuals were HIV negative. In Group A (HIV+) 66.1% had rheumatic manifestations including arthralgias, Reiter's syndrome, arthritis, enthesitis, psoriatic arthritis, Sjögren's syndrome, myopathy, septic arthritis, and lupus-like illness. In contrast, in Group B (HIV-) only 2 had arthralgias, 2 Reiter's syndrome, and 1 rheumatoid arthritis. In summary, rheumatic complaints are common in patients with HIV, and HIV positivity confers an increased susceptibility in populations with similar risk factors for HIV infection.

Adolescent↗
PubMed1990

Localization of the von Hippel-Lindau disease gene to a small region of chromosome 3.

We studied 25 families with von Hippel-Lindau disease (VHL) to locate VHL more precisely on chromosome 3. We found that VHL was linked to RAF1, confirming previous observations, and to two polymorphic DNA markers, D3S18 and D3S191. Multipoint linkage analysis indicated that the most likely location for VHL was in the interval between RAF1 and D3S18. D3S18 was located at 3p26. Genetic heterogeneity was not detected in this panel of von Hippel-Lindau disease families. The polymorphic markers RAF1, D3S18, and D3S191 should be useful in identifying asymptomatic gene carriers in VHL families and in guiding efforts at gene isolation.

Chromosome Mapping↗
PubMed1990

Preparative cytoreductive surgery in patients with metastatic renal cell carcinoma treated with adoptive immunotherapy with interleukin-2 or interleukin-2 plus lymphokine activated killer cells.

A total of 63 patients with metastatic renal cell carcinoma with the primary kidney tumor in place was accepted as candidates for immunotherapy at the Surgery Branch of the National Cancer Institute. Of the 63 patients 54 underwent nephrectomy and 9 were treated with the primary kidney tumor in place. Many of the patients underwent associated procedures, such as regional lymphadenectomy (11), venacavotomy with extraction of tumor thrombus (9), hepatic resection (2), pulmonary wedge resection (2), cholecystectomy (2), splenectomy (2), distal pancreatectomy (1), omentectomy (1) and contralateral adrenalectomy (1). Of the 54 patients 20 were not able to enter therapy because of tumor-related (17) or other medical (3) reasons that developed between the operation and therapy, while 34 were able to receive immunotherapy postoperatively. The 20 patients who were treated with either high dose interleukin-2 or interleukin-2 plus lymphokine activated killer cells soon postoperatively (mean 2.1 months) were able to tolerate roughly the same amount of interleukin-2 as the 74 who had undergone nephrectomy before referral to our institute and who were treated for a mean of 22 months after nephrectomy. Further studies, including a prospective, randomized trial, will be required to define the role of nephrectomy in patients with advanced renal cell carcinoma before treatment with interleukin-2 based immunotherapies.

Carcinoma, Renal Cell↗
PubMed1990

Optic nerve involvement associated with the multiple evanescent white-dot syndrome.

Five patients presenting with signs and symptoms of primary optic nerve disease were, after careful examination, diagnosed as having the multiple evanescent white-dot syndrome. Optic nerve findings in these patients included disc edema, central visual loss, enlarged blind spots, and other optic nerve field defects. The subtlety of the white spots in some cases made the diagnosis difficult. Multiple evanescent white-dot syndrome should be considered in the differential diagnosis of young, healthy patients who present with unilateral or bilateral optic nerve dysfunction.

Adult↗