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Biomedical subjects

M Weiss

Publications and source records attributed to M Weiss.

At least 361 records · Page 20Linked to original sources
PubMed1995

Increased amniotic fluid divalent cation concentration in preeclampsia.

Hypocalciuria due to reversibly enhanced tubular calcium reabsorption in preeclampsia has been previously described. As the fetus is exposed in utero to the toxemic environment, its kidney function may be similarly affected. We therefore evaluated the amniotic fluid (AF) concentrations of Ca2+, Mg2+, Zn2+, and Na+ in relation to creatinine in 12 preeclamptic women, 9 pregnant women with chronic hypertension, and 12 control pregnant women. Our data reveal an increased AF Ca2+, Mg2+, and Zn2+ to creatinine ratio in preeclampsia 451 +/- 283; 164 +/- 94; 787 +/- 124 Eq/mol, respectively) as compared with chronic hypertension (256 +/- 141; 94 +/- 46; 504 +/- 124 Eq/mol, respectively), and normal controls (274 +/- 132; 83 +/- 19; 477 +/- 124 Eq/mol, respectively; p < 0.05). Na+ concentration did not vary significantly among the three groups. It is suggested that the higher AF divalent cation concentration in preeclampsia may be due to lower maternal urinary excretion thereby increasing the fetal divalent cation load.

Adult↗
PubMed1995

Stereoselective suppression of neutrophil function by ketamine?

The effects of the commercially available ketamine preparation (Ketanest), the ketamine racemate and of the two enantiomers, the R(-)-racemate and the S(+)-racemate, as well as its drug-free solvent were examined by N-formyl-methionyl-leucyl-phenylalanine-(FMLP)- and zymosan-induced oxygen radical production of polymorphonuclear cells (PMN). The racemate and the two enantiomers of ketamine suppressed FMLP- and zymosan-induced chemiluminescence of PMN in a dose-dependent fashion to the same extent. Therefore suppression of chemiluminescence of PMN by ketamine does not result from a specific receptor interaction.

Cell-Free System↗
PubMed1995

[Studies of facilities with increased abortion rates in cattle].

Cases of abortions in cattle were investigated using several different laboratory procedures. The purpose was to collect information on an individual animal and on a herd basis that would allow a correct etiological diagnosis and also the institution of prophylactic measures. The cause of the abortion was diagnosed in 30% of the cases and in 16.3% of the herds. Due to the complexity of the problem, there is no routine diagnostic procedure that can universally be recommended and applied. There was no association between the number of tests performed or the number of herd mates included in the diagnostic work-up and the diagnostic success rate. In order to make a more efficient use of the diagnostic procedures, a better understanding of the mechanisms leading to abortion, on an individual animal basis and on a herd basis, is required.

Abortion, Veterinary↗
PubMed1995

Spontaneous regression of hepatocellular carcinoma.

Spontaneous regression of cancer is a rare phenomenon seldom described in patients with hepatocellular carcinoma. A case of spontaneous regression of hepatocellular carcinoma is reported and compared with the reports published in the English literature. A 52-yr-old man presented with biopsy-proven hepatocellular carcinoma, which was considered to be unresectable at initial laparotomy. The tumor subsequently regressed without specific treatment, as assessed radiologically and by normalization of a previously elevated alpha-fetoprotein level. At repeat laparotomy 14 months after initial diagnosis, intraoperative ultrasound failed to disclose a hepatic mass, and multiple biopsies showed no evidence of malignancy. To date, only nine case reports of apparently spontaneous regression of hepatocellular carcinoma have been published in the English literature. Clinical characteristics discriminating these patients from less fortunate patients with hepatocellular carcinoma could not be identified. The mechanisms underlying this intriguing phenomenon remain unknown.

Biopsy↗
PubMed1995

Elder abuse and neglect: how to recognize warning signs and intervene.

Elder mistreatment, whether abuse or neglect, can be classified as physical, psychological, or financial/material. Several types of mistreatment may occur simultaneously. Abuse occurs across all socioeconomic, racial, and religious lines. Risk factors include a history of mental illness or alcohol/drug abuse, a family history of violence, isolation of the victim, and recent stressful events in the life of the victim or abuser. For the physician the patient workup includes a careful history and physical exam, including cognitive evaluation. Ask about living arrangements, financial status, social supports, and emotional stressors. If possible, observe the interaction between the patient and family member or caregiver. Helpful resources include your state's Office of Protective Services and the American Medical Association's recently published guidelines for diagnosis and treatment of elder abuse and neglect.

Aged↗
PubMed1995

Paradoxical blockade of beta adrenergically mediated inhibition of stimulated eosinophil secretion by salmeterol.

Salmeterol (SALM) is a long-acting beta 2 adrenoceptor agonist that causes prolonged relaxation of airway smooth muscle. To determine whether this agent also causes prolonged inhibition of stimulated eosinophil secretion, we studied interactions between SALM and albuterol (ALB) in inhibiting eosinophil peroxidase (EPO) secretion in human eosinophils in vitro. Peripheral blood eosinophils were isolated from 18 human volunteers by negative immunoselection, and secretion of EPO was elicited with 10(-6) M formyl-met-leu-phe (fMLP) + 5 micrograms/ml cytochalasin B (CytB) in aliquots of 10(5) cells. Eosinophils were pretreated with either 10(-8) M ALB, 10(-8) M SALM or SALM + ALB for 5 min to 18 hr at 37 degrees C. Pretreatment with ALB for 5 min caused inhibition of stimulated secretion of EPO to 783 +/- 210 ng/10(6) cells vs. 1475 +/- 286 ng/10(6) cells for eosinophils not treated with ALB (P < .05; n = 5). Inhibition of EPO secretion caused by ALB was sustained for 30 min (924 +/- 160 ng/10(6) cells; P < .05 vs. fMLP + CytB; n = 5). By contrast, SALM had no inhibitory effect on fMLP-induced secretion after incubation for 5 min to 18 hr. In cells obtained from four separate isolations, pretreatment with 10(-8)M SALM before addition of ALB blocked the inhibition of EPO release caused by 10(-8)M ALB alone (486 +/- 28 ng/10(6) cells for ALB alone vs. 902 +/- 32 ng/10(6) cells for SALM + ALB; P < .01; n = 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1995

Aggressive behaviour as a cause of psychiatric admission: a comparison between schizophrenic and affective disorder patients.

One hundred and fifty-six subjects were randomly chosen from 1,560 patients admitted to two psychiatric hospitals in Israel during 1991. The subjects' files were retrospectively studied to determine whether aggressive behaviour was the reason for psychiatric admission. We examined the relationship between aggressive behaviour, major psychiatric disorders (schizophrenia and affective disorder) and demographic variables (sex, age, family status and education). We also studied the monthly distribution of aggression throughout the year and the correlation to daily photoperiod duration. Forty-six per cent of the admissions related to aggressive behaviour. Schizophrenic patients were overly represented in the aggressive group. The monthly distribution of aggressive behaviour differed between schizophrenic and affective disorder patients. While the latter showed a seasonal pattern of aggressiveness, with a statistically significant peak during spring and winter, schizophrenic aggressive patients were distributed equally throughout the year. No statistically significant correlation was found between the incidence of aggression and the photoperiod duration.

Adult↗
PubMed1994

An early haematopoietic defect in mice lacking the transcription factor GATA-2.

Blood cell development relies on the expansion and maintenance of haematopoietic stem and progenitor cells in the embryo. By gene targeting in mouse embryonic stem cells, we demonstrate that the transcription factor GATA-2 plays a critical role in haematopoiesis, particularly of an adult type. We propose that GATA-2 regulates genes controlling growth factor responsiveness or the proliferative capacity of early haematopoietic cells.

Anemia↗
PubMed1994

Reduction of the incidence of rejection by adjunct immunosuppression with photochemotherapy after heart transplantation.

In this study, photochemotherapy (PCT) was used for adjunct immunosuppression in the first six months after heart transplantation (HTx). Fifteen patients after orthotopic HTx were included in the study; all received standard triple-drug immunosuppression including cyclosporine, azathioprine and glucocorticoids, but no adjunct therapy with mono- or polyclonal antibodies. The patients were divided into three groups: group I served as control with no additional treatment; group II received adjunct treatment with 10 courses of PCT (single-day treatments); and group III received 20 PCT courses since it was given each time on two consecutive days. PCT was started in both groups on day one after HTx; it was applied with a higher frequency in the early postoperative period and thereafter continued at four-week intervals for a total of 6 months. The photopheresis method for PCT included extracorporeal UVA irradiation of mononuclear cells that were treated with the photosensitive drug 8-methoxypsoralen (8-MOP) and subsequently retransfused to the patient. A new liquid form of 8-MOP was added directly to the buffy coat, resulting in reliable and sufficient drug levels in the cell suspension during the irradiation period; problems caused by oral application due to unpredictable variations in gastrointestinal absorption were thus prevented. Analysis of the total numbers of acute rejection episodes (AREs) within the first four weeks after HTx revealed a more impressive decrease by double PCT (group III, 3 AREs) than by single PCT (group II, 5 AREs) in comparison with the control (group I, 6 AREs). Over the total observation time (mean: 9.6 months), however, both PCT schedules reduced the total number of AREs observed in the control group (20 AREs) equally by more than 50% (9 AREs each in groups II and III) (P = 0.007). Furthermore, PCT treated patients had significantly fewer infections (6 infections in each group) than control group patients (15 infections) (P = 0.026); this, however, may be accounted for by the higher number of acute rejections in the control group and consequent increase in unspecific immunosuppression treatment. Our results suggest that PCT is a safe and effective method of adjunct immunosuppression that can be applied early in the postoperative period; it reduces the number of rejection episodes and does not increase the risk of infections.

Adult↗
PubMed1994

CNRS defended.

Explore the source record for details and available documents.

France↗
PubMed1994

A comparison of clinical, pathological and radiological findings with magnetic resonance imaging studies of lymphomas in patients with Sjögren's syndrome.

In the past few years a variety of papers on magnetic resonance imaging (MRI) of the salivary glands have been published, mainly focusing on the evaluation of salivary gland tumors. More recently, non-tumorous lesions have also been examined with this imaging technique. In Sjögren's syndrome (SS) a characteristic inhomogeneous pattern with a "honeycomb-like" appearance of the parotid gland tissue has been shown in the T2-weighted sequence. This study shows MRI findings in four cases of intraglandular lymphoma occurring in patients with SS. Four patients with suspected lymphomas were examined with MRI, following which all lesions were either biopsied or removed. This enabled us to correlate clinical, radiological and pathological findings. Results indicate that MRI is a useful imaging tool in the detection of intraglandular lymphatic infiltrates, although it is not possible to distinguish morphologically between a localized lymphatic infiltrate and an early stage malignant lymphoma. Nevertheless, MRI is considered to be a valuable non-invasive method for deciding whether or not to perform a biopsy. Due to the excellent soft tissue differentiation obtained, it is also helpful for the surgeon to plan and perform a successful biopsy with minimal risk to the facial nerve.

Aged↗
PubMed1994

Capillary leak syndrome associated with elevated IL-2 serum levels after allogeneic bone marrow transplantation.

The pathophysiological mechanisms involved in the development of a spontaneous systemic capillary leak syndrome (CLS) are unknown. In contrast, CLS is a well-known side effect of high-dose interleukin-2 (IL-2) therapy in solid tumors. We report on a patient who developed CLS with high serum levels of endogenous IL-2 under immunosuppressive therapy for chronic graft-versus-host disease (GvHD) after allogeneic bone marrow transplantation (BMT). Generalized edema persisted for 10 weeks. The condition resolved after antibiotic therapy of a septic shock with beta hemolyzing streptococci group A. Thus, a latent infection may alter cytokine homeostasis and may cause CLS in BMT patients.

Adult↗
PubMed1994

Stereotactic core needle biopsy of mammographic breast lesions as a viable alternative to surgical biopsy.

BACKGROUND: Stereotactic needle biopsy technique has received considerable attention as a possible alternative to surgical biopsy of nonpalpable breast lesions. The exact role of this procedure in the management of mammographic breast lesions has not yet been accurately defined. METHODS: Data have been collected prospectively on 416 patients over an 8-month period (January 1992 through August 1992). Of 416, 356 patients underwent only stereotactic breast biopsy with a 14-gauge needle. Sixty patients underwent stereotactic breast biopsy followed by surgical biopsy. Based on mammographic findings before biopsy, lesions were classified as benign (24%), likely benign (49%), malignant (2%), likely malignant (6%), and indeterminate (19%). The number of core biopsy specimens obtained from each patient ranged from one to six. RESULTS: The specimen was considered adequate in 98% of cases. Complications were minimal. The tissue diagnosis was benign in 92% and malignant in 8% of patients. In those patients undergoing surgical and stereotactic biopsy, 57 of 60 had matching histopathological results, representing an agreement rate of 95% (p < 0.001). The three patients whose histopathological results did not match had malignant diagnoses on stereotactic biopsy that were subsequently not identified in the modified radical mastectomy specimen because the entire focus of malignancy was removed by the several passes made by the core needle during biopsy. No patient had a negative stereotactic biopsy result in whom malignancy was later detected by surgical biopsy. CONCLUSIONS: This study indicates excellent agreement between surgical and stereotactic needle biopsy findings. Stereotactic biopsy with a 14-gauge needle could obviate the need for surgical biopsy in certain women with radiologically benign, likely benign, and indeterminate lesions.

Algorithms↗
PubMed1994

Lung preservation with Euro-Collins, University of Wisconsin, Wallwork, and low-potassium-dextran solution. Université++ Paris-Sud Lung Transplant Group.

Using isolated rat lungs, we compared prevention of ischemia-reperfusion injury provided by flushing the lungs with modified Euro-Collins solution (EC), University of Wisconsin solution (UW), low-potassium-dextran solution (LPD), or Wallwork solution (WA). After 4 hours' and 6 hours' cold ischemia, reperfusion injury was assessed on the basis of changes in filtration coefficients (Kfc) and pressure-flow curves, characterized by the slope of the curves (incremental resistance) and the extrapolation of this slope to zero flow (pulmonary pressure intercept [Ppi]). After 4 hours, Kfc and Ppi were higher with EC than with UW, LPD, and WA, and the incremental resistance was higher with EC and UW. After 6 hours, Kfc and incremental resistance Ppi were higher with LPD than with WA. Because ischemia-reperfusion injury is associated with decreased endothelial synthesis of prostacyclin and nitric oxide, we tested whether the addition of prostacyclin or the nitric oxide precursor L-arginine to WA would improve preservation. The Kfc and Ppi were lower with both treatments. In conclusion, ischemia-reperfusion injury was best prevented by using WA. The favorable effect of prostacyclin or L-arginine emphasizes the role played by endothelial dysfunction in ischemia-reperfusion injury.

Adenosine↗
PubMed1994

Haemopoietic cell renewal in radiation fields.

Space flight activities are inevitably associated with a chronic exposure of astronauts to a complex mixture of ionising radiation. Although no acute radiation consequences are to be expected as a rule, the possibility of Solar Particle Events (SPE) associated with relatively high doses of radiation (1 or more Gray) cannot be excluded. It is the responsibility of physicians in charge of the health of astronauts to evaluate before, during and after space flight activities the functional status of haemopoietic cell renewal. Chronic low level exposure of dogs indicate that daily gamma-exposure doses below about 2 cGy are tolerated for several years as far as blood cell concentrations are concerned. However, the stem cell pool may be severely affected. The maintenance of sufficient blood cell counts is possible only through increased cell production to compensate for the radiation inflicted excess cell loss. This behaviour of haemopoietic cell renewal during chronic low level exposure can be simulated by bioengineering models of granulocytopoiesis. It is possible to define a "turbulence region" for cell loss rates, below which an prolonged adaptation to increased radiation fields can be expected to be tolerated. On the basis of these experimental results, it is recommended to develop new biological indicators to monitor haemopoietic cell renewal at the level of the stem cell pool using blood stem cells in addition to the determination of cytokine concentrations in the serum (and other novel approaches). To prepare for unexpected haemopoietic effects during prolonged space missions, research should be increased to modify the radiation sensitivity of haemopoietic stem cells (for instance by the application of certain regulatory molecules). In addition, a "blood stem cell bank" might be established for the autologous storage of stem cells and for use in space activities keeping them in a radiation protected container.

Aerospace Medicine↗
PubMed1994

Do barbiturates impair zymosan-induced granulocyte function?

PURPOSE: The dose-response relationship of commercially available preparations of methohexital, pentobarbital, phenobarbital, and thiopental and their respective drug-free solutions on granulocyte function was investigated to evaluate whether suppression of neutrophil chemiluminescence is mediated by the barbiturates themselves or by their drug-free solutions. Furthermore, it was assessed whether suppression of chemiluminescence is due to an interaction mainly with neutrophils or to free radical scavenging. METHODS: The dose-response effects of the four barbiturates on granulocyte function were tested by zymosan-induced neutrophil chemiluminescence and, in addition, in a cell-free chemiluminescence system. RESULTS: Methohexital and pentobarbital did not influence zymosan-induced neutrophil chemiluminescence, whereas phenobarbital and thiopental decreased neutrophil chemiluminescence in a dose-dependent fashion. Nonphysiological osmolality (531 mosmol/kg) caused this impaired neutrophil chemiluminescence at the greatest concentration of phenobarbital. Thiopental solely suppressed neutrophil chemiluminescence drug specifically. Because thiopental also reduced chemiluminescence generated in a cell-free system, free radical scavenging might contribute to the impaired neutrophil chemiluminescence observed with thiopental. CONCLUSIONS: With the exception of thiopental, barbiturates do not impair oxygen radical production during phagocytosis of neutrophils.

Cell-Free System↗