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Biomedical subjects

R Lichtenberg

Publications and source records attributed to R Lichtenberg.

At least 19 recordsLinked to original sources
PubMed1997

Role of maximal oxygen consumption in establishment of heart transplant candidacy for heart failure patients with intermediate exercise tolerance.

Maximal exercise oxygen consumption (VO2max) was measured in patients with chronic congestive heart failure undergoing evaluation for heart transplantation. Although VO2max correlated with survival for the group as a whole, it did not demonstrate survival discrimination for patients in the intermediate range (VO2max = 12 to 17 ml/kg/min) and should therefore not be used as a benchmark test for determination of appropriateness for cardiac transplantation in this group of patients.

Adult↗
PubMed1995

High-resolution CT of mastoid sinus pneumocele with external auditory canal stenosis.

A 34-year-old man presented with tinnitus and conductive hearing loss. CT demonstrated an expansile, air-containing cavity contiguous with mastoid air cells, narrowing the external auditory canal. This is a case of symptomatic pneumocele resulting in an air collection beneath external canal lining, possibly related to an abnormality in mastoid fusion.

Adult↗
PubMed1994

Dyshematopoiesis in combined immune deficiency with congenital neutropenia.

This report describes a patient with combined immune deficiency associated with congenital neutropenia (CID/CN) and reports a partial characterization of his hematopoietic abnormalities. The CID/CN syndrome described is characterized by neutropenia and by deficiencies in B-lymphoid and T-lymphoid cell number and function. Red cell and platelet counts were normal. In vitro assays indicate that the myeloid lineage was developmentally arrested at the level of the committed monocyte/granulocyte progenitor (CFU-GM), while precursors to the CFU-GM progenitor were normal. In vitro studies showed that the defect in myeloid development was not corrected with G-CSF or GM-CSF. However, combinations of cytokines present in conditioned media from the T-cell lines MO or C5MJ, or defined multiple cytokine combinations containing IL-1, IL-3, GM-CSF, kit ligand, IL-6, and IL-9, restored myelopoiesis in-vitro. In contrast, C5MJ-conditioned media did not correct deficiencies in immune function in the patient's lymphocytes and accessory cells. No abnormalities in the production of G-CSF, GM-CSF, M-CSF, or IL-1 from the patient could be identified to account for the defects in myelopoiesis orimmune function.

B-Lymphocytes↗
PubMed1994

Anti-lipid A monoclonal antibodies and anti-LPS antiserum effects on limulus activity of LPS.

Anti-lipid A monoclonal antibodies (A78S1 and A523) and anti-LPS antiserum can decrease the mortality due to endotoxic shock in the newborn rat. However, in vitro LPS detoxification of anti-lipid A monoclonal antibodies is not known. Thus, we studied in vivo effects of A78S1 (IgG), A523 (IgM), and anti-LPS antiserum on Limulus activity. Anti-LPS antiserum decreased Limulus activity of S. enteritidis, E. coli and S. typhosa LPS. However, neither A78S1 nor A523 decreased the Limulus activity of E. coli and S. typhosa LPS. A78S1 or A523 incubation with S. enteritidis LPS at different doses (0.1 to 100 ng/ml) did not alter the Limulus activity. Perchloric acid treatment after LPS incubation with A78S1 or A523 significantly decreased Limulus activity. Therefore, antilipid A monoclonal antibodies (A78S1 and A523) can bind LPS, but do not decrease Limulus activity.

Animals↗
PubMed1993

Cardiovascular effects of lightning strikes.

OBJECTIVES: The purpose of this study was to investigate the effects of lightning strikes on the cardiovascular system. BACKGROUND: A lightning strike can attack its victims in one of three ways: direct hit, splash or ground strike. The cardiovascular system can be affected directly by mechanical or electrical trauma during a direct hit or can be indirectly affected through effects on the total body with extensive catecholamine release or autonomic stimulation. Reported effects include hypertension, tachycardia, nonspecific electrocardiographic (ECG) changes including prolongation of the corrected QT (QTc) interval, transient T wave inversion and myocardial necrosis with creatine kinase-MB (CK-MB) fraction release. METHODS: Nineteen victims from five separate lightning strikes were studied over a 2-month period. Each patient was evaluated by serial ECG, CK-MB determinations and echocardiography. RESULTS: The early (0 to 72 h) effects of lightning were demonstrated on the ECG by ST segment elevation consistent with acute current of injury, prolonged QTc interval with direct hits and nonspecific ST and T wave changes. On echocardiography, segmental or global ventricular dysfunction was seen, and pericardial effusion was also detected. During the intermediate (3- to 14-day) period, new and often marked ECG changes consistent with pericarditis or ischemia were seen. No new echocardiographic changes were detected, however, and the early abnormalities including severe left ventricular dysfunction with cardiogenic shock have reversed. The late (1 to 12 months) period revealed only one patient with long-term sequelae (recurrent pericarditis that persisted for 5 months). CONCLUSIONS: Unless both entrance and exit sites are limited to the lower limbs, direct and splash lightning strikes cause myocardial damage as assessed by abnormal serum enzyme determinations or abnormal echocardiographic findings. Only direct hits resulted in echocardiographic abnormalities or a prolonged QTc interval. The degree of myocardial injury can be severe with left and right ventricular ejection fraction < 15% and can be reversible.

Adult↗
PubMed1992

Ureteric obstruction by the right testicular vein: CT diagnosis.

The close relationship of the ureter and gonadal blood vessels is often clearly demonstrated by computed tomography (CT). A case of ureteral obstruction in a man possibly caused by the crossing testicular vein is presented. Unlike the ovarian vein syndrome in women, which is often related to pregnancy and/or venous thrombosis, no predisposing factors were found.

Adult↗
PubMed1990

Endotoxin and the hyperdynamic circulation of portal vein-ligated rats.

Humoral factors may be responsible for the hyperdynamic circulation seen in portal hypertension. Endotoxin, a peripheral arteriolar vasodilator, has been proposed to mediate this hemodynamic picture. We examined the pathogenic role of endotoxin in portal vein-ligated rats, a prehepatic portal hypertensive model with a well-developed hyperdynamic circulation. To this end, we (a) administered oral neomycin, a poorly absorbable antibiotic, at doses of 50 and 100 mg/day for 7 days and found no evident splanchnic hemodynamic effects of a 2-log-fold reduction of cecal aerobic bacterial flora as assessed by the radioactive microsphere technique in portal vein-ligated rats studied in the postanesthesia awake state; (b) assayed endotoxin in arterial samples using a quantitative limulus assay and found no evidence of endotoxinemia in PVL rats; (c) induced a state of endotoxin tolerance by repeated daily intraperitoneal injections of low-dose endotoxin and found no amelioration of the hyperdynamic state in portal vein-ligated rats. Our results do not support the hypothesis that endotoxin plays a major pathogenic role in the hyperdynamic circulation of this experimental model.

Ammonia↗
PubMed1989

Bromate poisoning.

Explore the source record for details and available documents.

Acute Kidney Injury↗
PubMed1989

[An epidemiological study of 1000 sterile couples].

Our purpose was to study the characteristics of our infertile population, to evaluate prognostic fertility parameters and to know our pregnancy rates. One thousand infertile couples were studied under a protocol by factors. We found the highest alteration in the ovarian factor (35%), followed by the tuboperitoneal factor (28%) and male factor (26%). The woman's age, the duration of infertility and multifactorial infertility (17.6%), were of prognostic importance. Our pregnancy rate of 61.4% compares with the reported in the literature. We believe that establishing an infertility protocol with a multidisciplinary approach, helps to a more precise diagnosis and more specific treatments with better results.

Adult↗
PubMed1984

Ovarian function following a single administration of depo-medroxyprogesterone acetate (DMPA) at different doses.

The effects of a single administration of depo-medroxyprogesterone acetate (DMPA) at different doses upon ovarian function was studied in a group of healthy ovulating Mexican women. Single doses of DMPA of 25, 50, 100, and 150 mg were intramuscularly administered. Ovarian function was assessed by the measurement of the serum levels of 17 beta-estradiol and progesterone in blood samples drawn twice weekly for 6 months after DMPA administration. The results disclosed that ovulation was inhibited in all cases for at least 3 months following DMPA administration even at the lowest dose, whereas the return of luteal function exhibited a significant positive correlation with the dose of DMPA administered. As expected, follicular activity preceded that of luteal function in all subjects. A correspondence between serum medroxyprogesterone concentrations and ovarian function was found. The overall data indicated that the currently used contraceptive formulation (150 mg) is well above the effective pharmacologic range, and suggested that the dose can be substantially reduced without losing its anovulatory potency.

Adolescent↗
PubMed1983

Sister-chromatid exchanges and cell kinetics in human and rabbit lymphocytes exposed in vivo and in vitro to 2-bromo-alpha-ergocryptine.

The possible mutagenic and DNA-synthesis inhibitory effects of 2-bromo-alpha-ergocryptine, a new semi-synthetic ergot alkaloid, was studied in human and rabbit lymphocytes exposed to it in vivo and in vitro. The analysis of SCE was mainly used to evaluate potential mutagenicity, and the mitotic and DNA-synthesis inhibition was explored by examining the proportions of first-, second- and third-division metaphases in the corresponding lymphocyte cultures. The results obtained show that 2-bromo-alpha-ergocryptine does not induce SCE in the cell systems tested, or structural chromosome aberrations in human lymphocytes in vivo. On the other hand, a marked mitotic inhibitory effect and associated cell kinetic changes could be clearly attributed to the drug, probably related to its cytotoxicity.

Animals↗
PubMed1981

Pharmacokinetics of ethynyloestradiol in women for different populations.

The pharmacokinetics of a dose of 50 microgram ethynyloestradiol administered orally was studied in fourteen centres. Absorption was rapid and the highest serum concentrations of total ethynyloestradiol were found in most subjects at 1 h and by 24 h concentrations were less than 250 pg/ml. Calculation of the half-lives for absorption, distribution and elimination showed wide variations between subjects, the half-life of elimination varying from 2.5 h to more than 30 h. Bioavailability as measured by the area under the serum ethynyloestradiol concentration-time curve also showed more than a ten-fold variation. Intra-centre differences in the various parameters measured were as large as the inter-centre differences.

Biological Availability↗