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Biomedical subjects

M Kotler

Publications and source records attributed to M Kotler.

At least 163 records · Page 9Linked to original sources
PubMed1982

Hypocalcemia in critically ill patients.

Hypocalcemia is an important metabolic problem in critical care medicine. To determine the frequency of this problem and the patient subsets at risk, a retrospective study of a large series of ICU patients was performed. During the study period, 259 patients were admitted to the ICU, of whom 210 (81%) had a serum calcium (Ca++) measured. Of these 210 patients, 135 (64%) were hypocalcemic (serum Ca++ less than 8.5 mg/dl) and 75 (36%) were normocalcemic. Serum albumin concentration was less than 3.5 g/dl in 70% of the hypocalcemic patients who hd albumin measured, suggesting that the ionized Ca++ concentration may have been normal in many of these patients. On the other hand, 32% of the hypocalcemic patients were alkalotic (pH greater than or equal to 7.45) which indicates that ionized Ca++ levels may have been low because Ca++ binding to protein increases with alkalosis. Gastrointestinal bleeders and postabdominal surgery patients were more likely to have low total serum Ca++ whereas cardiac and neurosurgical patients were more likely to have a normal total serum Ca++ (p less than 0.05). Ionized Ca++ was calculated in 36 of the normocalcemic and 80 of the hypocalcemic patients. The hypocalcemic group had significantly lower ionized Ca++ levels when compared to those of the normocalcemic group (p less than 0.001). Patients with low serum Ca++ values spent a longer time in the ICU (p less than 0.01), had an increased incidence of renal failure and sepsis (p less than 0.01), had an increased mortality rate (p less than 0.001), and received a greater number of blood transfusions (p less than 0.001) than patients in the normocalcemic group. It is concluded that: (1) hypocalcemia is a frequent finding in critically ill patients; (2) determining ionized Ca++ levels is useful because many ICU patients have alterations in both arterial pH and serum albumin levels; (3) hypoalbuminemia, sepsis, red cell transfusions, and renal failure are predisposing factors for hypocalcemia; and (4) hypocalcemic patients do less well clinically than normocalcepatientsmic patients.

Calcium↗
PubMed1981

Theiler's murine encephalomyelitis virus group includes two distinct genetic subgroups that differ pathologically and biologically.

The intracellular development and RNA composition of Theiler's murine encephalomyelitis virus (TMEV) isolates were determined by electron microscopy, sucrose gradient centrifugation, and RNase T1 fingerprinting. Replication of FA virus, a virulent strain of TMEV, was characterized by the appearance of viral crystalline arrays in the cytoplasm of infected cells. In contrast, cells infected with the less virulent isolates (WW, TO4, BeAn 8386, and Yale) showed no crystalline arrays; instead, virions were found to be arranged between two layers of membranes in the cytoplasm of infected cells. Analysis of the RNAs of TMEV isolates showed that the RNAs were single-stranded molecules having sedimentation coefficients of 35S. RNase T1 fingerprinting of TMEV RNA revealed that striking differences between the virulent and less virulent TMEV isolates existed. Moreover, base composition analysis of RNase T1-resistant oligonucleotides of two TMEV isolates which represented the two subgroups indicated that there were no substantial oligonucleotides common to both subgroups. Based on these findings and the known difference in virulence, we suggest that the TMEV group contains two genetically district subgroups of viruses.

Animals↗
PubMed1979

Retrovirus-like particles in EBV-negative Burkitt's lymphoma cell line but not in EBV-DNA-positive lines from patients with ataxia telangiectasia and Down's syndrome.

Retrovirus-like particles can be recovered by arginine deprivation from the BJAB-1 Epstein-Barr virus (EBV) negative cell line derived from an African patient with typical Burkitt's lymphoma. These particles resemble retroviruses in their morphology and in their physicochemical properties. Particles with a similar morphology were obtained from derivative cell lines established by infecting BJAB-1 cells with EBV. On the other hand, retrovirus-like particles could not be induced in EBV-DNA-positive lymphoblastoid cell lines derived from non-leukaemic patients with ataxia telangiectasia and Down's syndrome and from a patient with infectious mononucleosis.

Ataxia Telangiectasia↗
PubMed1978

Simultaneous production of mouse endogenous virus and Rous sarcoma virus by Schmidt-Ruppin virus infected mouse cells.

Schmidt-Ruppin Rous sarcoma virus infected chick cells injected into newborn C3H/f mice gave rise to tumours at the site of inoculation. These tumours were transplantable in adult C3H/f mice and were able to induce tumours in the wing of adult Leghorn chickens. Tumour cells from the 18th passage in mice were used to establish a cell line in tissue culture (C3HSR). These cells released C-type virus particles that produced foci and were able to propagate in chick cells. Cloning of the C3HSR cells demonstrated that the same cell expressed both avian and murine antigens. Mouse cells infected with virus released by C3HSR cells produced murine leukaemia virus-like particles as revealed by the reverse XC syncytial test and by immunofluorescence tests.

Animals↗
PubMed1975

Oncornavirus-like particles released from arginine-deprived human lymphoblastoid cell lines.

Type-C RNA tumor virus particles were released from three different human lymphoblastoid cell lines after incubation in arginine-deficient medium. The released virus-like particles were characterized by (a) their ability to band in sucrose gradients at a density of 1.16-1.18 g/ml; (b) the presence of an RNA-directed DNA polymerase activity resembling that of the oncornaviruses; and (c) isolation of cores that band at a density of 1.26-1.27 g/ml in sucrose gradients. Examination of the arginine-deprived human lymphoblastoid cell line strain P3HR-1 by electron microscopy revealed the presence of C-type particles in the intracellular spaces.

Arginine↗
PubMed1975

Transformation of cultured human embryonic fibroblasts by oncornavirus-like particles released from a human carcinoma cell line.

A fibroblast-like cell culture was established from a stomach biopsy of a patient with metastatic adenocarcinoma. One of the cultures, at the 6th passage level, left unattended for a month at 37 degrees, produced numerous foci of epithelioid cells. Upon subculturing, an epithelioid cell line, designated HCCL (human carcinoma cell line), was established. The HCCL cells released particles possessing the characteristics of oncornaviruses: density 1.175 g/ml, cores with a density of 1.22-1.26 g/ml, high-molecular-weight RNA (60-70S) and RNA-instructed DNA polymerase activity (deoxynucleosidetriphosphate:DNA deoxynucleotidyltransferase, EC 2.7.7.7). Inoculation of particles released from HCCL cells into cultures of human embryo muscle fibroblasts resulted in the appearance of foci of transformed cells.

Carcinoma↗
PubMed1975

A study of the dynamic relations between the mitral valve echogram and phasic mitral flow.

Echocardiographically recorded mitral valve motion was compared with phasic transmitral flow in 17 open chest dogs. The normal mitral valve opening started with the onset of mitral flow and reached its full excursion while flow was still accelerating. Complete valve opening occurred .044 sec (plus or minus .002 sem) before peak flow, during which time an average of 17.6 percent of total mitral filling volume had passed through the valve. In contrast to the opening movement, the closing motion of the anterior mitral valve cusp lagged behind the deceleration of mitral flow. The E-F phase of the mitral valve echogram started while mitral flow was still increasing and resulted from a combined posterior motion of the cusp and the ring. The E-F slope of the normal valve was found to decrease with reduced cardiac output. The amplitude of the anterior cusp excursion did not reflect the amount of mitral flow. Prolonged P-R interval may induce a mid-diastolic reversal of mitral flow which, in turn, may be accompanied by partial or complete valve closure, occurring before the onset of ventricular contraction. Such premature closure of the mitral valve may be accompanied by a certain amount of regurgitant flow.

Animals↗
PubMed1972

Reverse transcriptase-containing particles induced in rous sarcoma virus-transformed rat cells by arginine deprivation.

Incubation of rat cells transformed by Rous sarcoma virus (RSV) in an arginine-deficient medium resulted in accumulation of particles in the culture medium. Such particles did not appear when the transformed rat cells were incubated in a complete medium nor in the medium of primary rat cells which were incubated either in arginine-deficient or complete media. The particles which were released from the arginine-deprived transformed rat cells resemble C-type particles in their properties. These particles band in sucrose gradients at a density of 1.16 g/ml and contain 35S ribonucleic acid (RNA) molecules and a reverse transcriptase activity. Analysis of the cytoplasm of transformed and primary rat cells, deprived and undeprived of arginine, revealed the presence of reverse transcriptase-containing particles which banded in sucrose gradients at a density of 1.14 g/ml. These particles differed from the particles released into the medium by the arginine-deprived RSV-transformed rat cells. The deoxyribonucleic acid (DNA) molecules synthesized in vitro by the reverse transcriptase present in the particles isolated from the medium of arginine-deprived cells hybridized to RSV RNA, whereas the DNA synthesized by the cell-bound enzyme had no homology to RSV RNA.

Animals↗