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Biomedical subjects

M Beck

Publications and source records attributed to M Beck.

At least 271 records · Page 15Linked to original sources
PubMed1990

Molecular approaches to enteroviral diagnosis in idiopathic cardiomyopathy and myocarditis.

Enteroviruses are thought to be etiologic agents in some cases of human myocarditis and dilated cardiomyopathy. Murine models of acute coxsackievirus B3 myocarditis implicate coxsackie B viruses as possible causes of human myocarditis. Indirect evidence implicating enteroviruses as causative agents in human heart disease derives from serologic studies. More recently, direct evidence for enteroviral presence in diseased human heart tissues has been obtained by nucleic acid hybridization analyses. Although the data suggest that enteroviral infections may be associated with 18% to 50% of cases of myocarditis or dilated cardiomyopathy, or both, causality has not been established. Unanswered questions remain regarding the specific identity of the enteroviral genomes detected in the human heart and the potential for enteroviruses to persist in the heart.

Cardiomyopathies↗
PubMed1989

Expression of the human chondrocyte phenotype in vitro.

We report a culture scheme in which human epiphyseal chondrocytes lose their differentiated phenotype in monolayer and subsequently reexpress the phenotype in an agarose gel. The scheme is based on a method using rabbit chondrocytes. Culture in monolayer allowed small quantities of cells to be amplified and provided a starting point to study expression of the differentiated human chondrocyte phenotype. The cells cultured in monolayer produced type I procollagen, fibronectin, and small noncartilaginous proteoglycans. Subsequent culture in agarose was associated with the acquisition of typical chondrocyte ultrastructural features and the synthesis of type II collagen and cartilage-specific proteoglycans. The switch from the nonchondrocyte to the differentiated chondrocyte phenotype occurred under these conditions between 1 and 2 wk of agarose culture and was not necessarily homogeneous throughout a culture. This culture technique will facilitate direct investigation of human disorders of cartilage that have been addressed in the past by alternative approaches.

Cell Differentiation↗
PubMed1989

Mumps vaccine L-Zagreb, prepared in chick fibroblasts. I. Production and field trials.

Leningrad-L3 Mumps Vaccine virus has been further attenuated by adaptation and passage on SPF chick embryo fibroblast cell cultures. This new mumps strain has been designated L-Zagreb and has been used to prepare mumps vaccines which meet the WHO requirements. Observations during both the field trial period prior to registration and during the later use of the vaccine showed that the few reactions observed were mild and that seroconversion was obtained in 88-98% of vaccines. The morbidity of mumps in Croatia declined more than tenfold after the introduction of the new vaccine. During a mumps epidemic, vaccine efficiency was calculated to be 97-100%.

Animals↗
PubMed1989

A prospective study on the lack of development of antisperm antibodies in women undergoing intrauterine insemination.

To test the hypothesis that intrauterine insemination with washed spermatozoa induces antisperm antibody formation, we measured serum antisperm antibody levels by the Immunobead technique in a population of women receiving exogenous gonadotropins. Antibody levels were measured before therapy (baseline) and then serially during subsequent stimulation cycles, for a maximum of six cycles. Twenty-eight patients underwent intrauterine insemination; each patient served as her own control. An additional 25 patients were treated with exogenous gonadotropins but did not undergo intrauterine insemination; they served as external controls. Antisperm antibody levels in women who underwent concomitant intrauterine insemination were compared with levels in those who did not. Of the 53 enrolled patients, 18 completed six treatment cycles, and 35 achieved pregnancy before six cycles. Forty-five patients (85%) had less than 10% Immunobead binding, six (11%) had binding between 10% and 25% (mean 16%, range 14% to 20%), and two had binding greater than 25% (28% and 42%, respectively). Mean binding was similar (less than 10%) in the intrauterine insemination and external control groups. Eighteen patients conceived in the intrauterine insemination group and seventeen in the control group. Of patients who conceived, all but one had less than 10% Immunobead binding at the time of conception (mean 1.6 months). In patients who did not conceive, there was no difference in Immunobead binding between control and intrauterine insemination groups after 6 months of therapy. Our data do not support the hypothesis that serum antisperm antibody levels, as detected by Immunobead binding, will increase in menotropin-stimulated women undergoing intrauterine insemination over a prolonged treatment period.

Adult↗
PubMed1989

An evaluation of volumes and concentrations of lidocaine in human inferior alveolar nerve block.

The purpose of this study was to evaluate, with the electric pulp tester, the anesthetic efficacy of 1.8 ml of 2% lidocaine with 1:100,000 epinephrine, 3.6 ml of 2% lidocaine with 1:200,000 epinephrine, and 1.8 ml of 4% lidocaine with 1:100,000 epinephrine in human inferior alveolar nerve block. Thirty subjects randomly received each of the solutions at three successive appointments. The first molar, canine, lateral incisor, and contralateral canine were tested with the pulp tester at various time intervals up to 55 min. Complete anesthesia was defined as an 80/80 reading with the pulp tester. No significant differences in anesthetic success or failure were found among the three solutions. Potential anesthetic problems (failure, noncontinuous anesthesia, slow onset, and short duration) occurred in 43 to 57% of the molars, in 43 to 60% of the canines, and in 57 to 80% of the lateral incisors. Complete anesthesia in the mandible is a meaningful clinical problem.

Adult↗
PubMed1989

An in vivo comparison of the step-back technique versus a step-back/ultrasonic technique in human mandibular molars.

This study compared the in vivo debridement efficacy of the step-back preparation versus a step-back/ultrasound preparation in the mesial root canals of vital human mandibular molars. Group 1 consisted of 15 teeth prepared with a step-back technique using intermittent irrigation with 5.25% sodium hypochlorite. Group 2 consisted of 23 teeth prepared with a step-back technique as in group 1 followed by 3 min of ultrasonic instrumentation (Cavi-Endo) using 5.25% sodium hypochlorite (30 ml per min). Group 3 consisted of 21 teeth which were uninstrumented and served as controls. Following extraction and histological preparation, the 1- and 3-mm levels of the canal and isthmus were evaluated for percentage of tissue removal using a compensating polar planimeter. At the 3-mm level, there were no statistical differences in canal or isthmus cleanliness between the step-back group and the step-back/ultrasound group. At the 1-mm apical level, statistical analysis indicated that the step-back/ultrasonic technique was superior to the step-back technique in canal (99.6% versus 88%) and isthmus (86% versus 10%) cleanliness.

Adult↗
PubMed1989

[Biogenic amines in the digesta of swine].

Concentrations of amines were analysed in the digesta of piglets and fattening pigs after refining using an aminoacid-analyser. Feed contained only small amounts of putrescine. In the stomach histamine, tyramine, putrescine and cadaverine were nearly equally distributed, whereas in the colon cadaverine presented the main part. Piglets with 24% CP had in stomach/small intestine/hindgut 4.2/10.2/9.6 mmol, with 18% CP-/5.5/4.9 mmol amines/kg DM digesta. Fattering pigs showed in jejunal digesta from 2.1 to 8.7 mmol, in the caecum 1 to 4.8 mmol and in the colon 0.2 to 2.2 mmol amines/kg DM. Increasing CF-contents and bactericide supplements in the diet lowered amine concentration in all gut sections not significantly.

Animal Feed↗
PubMed1989

Effect of calcium lactate in erosion and S. mutans in rats when added to Coca-Cola.

Thirty-six Sprague Dawley rats, 22 days of age, were divided randomly into three groups of 12 each and housed in a programmable feeder. The three experimental groups received either Coca-Cola (CC), Coca-Cola with calcium lactate (CC-CaL), or distilled water. The programmable feeder was set to deliver 17 equal volumes of fluid per day with each feeding period lasting between 80-90 min. All groups were given Diet MIT 305 in one premeasured amount per 24 hr period (ad libitum). The pH of the CC with calcium lactate was adjusted to match the CC without calcium lactate by the addition of citric and phosphoric acids. The test period lasted five weeks. Each week, the food and fluid consumed and the weight gain were measured. Erosion of the teeth was scored by the method of Restarski et al. (1945). ANOVA indicated that there was a significant difference in the amount of erosion among groups. A Newman-Keuls analysis showed that the mean erosion score of the CC group was significantly greater (P less than 0.05) than that of the CC-CaL and distilled water groups (54.2 +/- 0.12; 0.0275 +/- 0.0123; 0.132 +/- 0.070, respectively). There was no significant difference in erosion between the CC-CaL and distilled water groups. There was no difference in the amount of food and fluid consumed among the group of rats. In conclusion, calcium lactate added to CC resulted in significantly reduced tooth erosion in rats.

Analysis of Variance↗
PubMed1988

Newly synthesized proteoglycans in pseudoachondroplasia.

In an attempt to elucidate the biochemical defect in pseudoachondroplasia, proteoglycan metabolism was investigated in cartilage from a patient with the dominant form of this condition. Iliac-crest cartilage was radioactively labeled with 35S-sulfate and the newly synthesized proteoglycans examined for their hydrodynamic size and glycosaminoglycan composition. The banding pattern of the purified proteoglycans was analyzed by gel-electrophoresis using large pore polyacrylamide-agarose. We found a normal chain-length of glycosaminoglycans and a normal ratio of chondroitin-6-sulfate to chondroitin-4-sulfate. The proteoglycans were not enriched in keratan sulfate. Gel electrophoretic analysis of the proteoglycans disclosed a banding pattern comparable to that of two normal controls. In contrast to the findings of other authors no differences between the proteoglycans of pseudoachondroplastic and normal cartilage were detected.

Achondroplasia↗
PubMed1988

The task-force approach to solving radiology problems.

A task force approach to resolving radiology problems has been used successfully at Hartford Hospital. The involvement of nursing, medical staff, and other ancillary personnel has resulted in the solution of issues common to all hospitals and imaging departments, including problems in patient scheduling, transportation, monitoring, and preparation. Sharing of issues and ideas and the development of direct lines of communication have brought about beneficial change and contributed to quality patient care.

Communication↗