PubMed Health⌕ Search

Biomedical subjects

J Becker

Publications and source records attributed to J Becker.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Biostimulation of wound healing in rats by combined soft and middle power lasers].

For some time now, the combined soft- and middle-power laser has been used for treating wounds and various skin diseases, but its effect has not yet been confirmed in experiments on animals. For this reason, a controlled test on the effect of this laser on wound healing in rats was conducted. In 16 rats, 3-cm long skin incisions were made on the wall of the abdomen and then sutured using standard surgical technique with 5 stitches. Eight rats were then treated with laser light, the other 8 receiving a control treatment. The wounds were photographed on the 1st, 2nd, 3rd, 5th, 8th and 15th postoperative day. The photographs were shown to 10 doctors who rated the wounds from 1 to 4 on the basis of the criteria inflammation and adaptation. While the wounds of the laser group were not judged to be significantly better than those of the control group in terms of inflammation, adaptation was judged to be significantly better in the laser-treated group. This effect was particularly evident at the beginning of treatment (3rd day: average rating of laser group: 1.68; S = 0.32; control group: 2.41; S = 0.53; analysis of variance parameters for repeated measurements: p = 0.027 less than 0.05). These results demonstrate that in all probability the combined soft- and middle-power laser promotes the closing of wounds in rats, especially in the first postoperative days, while there is no positive effect on inflammation.

Animals↗
PubMed1990

Correlation between EEG spectral parameters and an educational evaluation.

EEG spectral parameters were computed in a group of children with different degrees of difficulty in learning to read and write. For statistical analyses, Z-transformed values according to normative age-regression equations were used to control the age effects. Canonical Correlation Analysis between absolute power in different bands and the categories of the educational evaluation (good, regular, poor and very poor) showed that more delta was probably related to a poor evaluation and more alpha in occipital areas to a good one. MONOVA also showed highly significant differences in the absolute power in many leads between children with different evaluations. As children with a poor evaluation very frequently had antecedents of risk factors related to brain damage and were from a low socioeconomic status, and both factors have been shown to affect absolute power, it may be that the differences observed were due to these causes. However, relative power correlated more with the learning problems. Children with minor difficulties, with no antecedents and with good socioeconomic status had more theta in almost all leads than children with a good evaluation and with the same characteristics. Children with a poor, or very poor, evaluation had more delta in left frontal and temporal areas (F3, F7 and T3) which may reflect underlying cerebral dysfunction of these regions directly involved in reading and writing processes.

Child↗
PubMed1990

Brainstem evoked potentials in learning disabled children.

Averaged brainstem auditory responses (BAER) were recorded using left and right ear stimulation with clicks of 90 dBs in two groups of primary school children (control and learning disabled). A linear multiple regression model was used in an attempt to demonstrate the effects of sex, high risk factors related to brain damage and learning disability on the evoked responses. Sex showed a strong influence in the latencies of the first five peaks, with girls having shorter latencies. Risk factors had an effect on the latency of peak V, the I-V interval and the V/I amplitude ration, but only when the left ear was stimulated. Learning disability had no significant influence according to this analysis. Multivariate test of complete homogeneity showed highly significant differences between LD and control boys when the left ear was stimulated and between control and LD girls when the right ear was stimulated. Principal component analyses revealed differences between the two groups: the BAER components of the control subjects showed a minor source of variance when the right ear was stimulated. A contrary effect was observed in LD children. Such differences might be related to ear preference and hemispheric dominance.

Acoustic Stimulation↗
PubMed1990

Early activation of heat shock genes in H2O2-treated Drosophila cells.

Drosophila cells of a diploid clone derived from line Kc were treated with 1 mM H2O2 for 1 to 20 minutes. Dot blot and Northern blot analysis of RNAs extracted from control and treated cells showed that the transcriptional activation of the 6 heat-shock genes tested was early, and maximal within 5 minutes of H2O2 treatment. Analysis of the kinetics of induction of the heat-shock proteins (hsps) after an exposure to H2O2 of 2 or 5 minutes, followed by removal, suggests that this brief treatment was sufficient to trigger the synthesis of all the hsps, which was maximal 1.5 to 3h after this short H2O2 treatment.

Animals↗
PubMed1990

Characterization and purification of DNA-RNA complexes related with 1731 and copia-like transposable elements in a Drosophila cell line.

DNA-RNA complexes were characterized and purified in a Drosophila melanogaster cell line. Such duplexes were shown to be specific of 1731 and other "copia-like" transposable elements. DNA-RNA complexes were purified through a Sephadex G-75 column from a global nucleic acid preparation or from a total RNA fraction prior to DNA-A and RNA-A treatment. They incorporated both labelled thymidine and uridine and their resistance or sensibility to enzymes or chemicals was consistent with that being expected with such hybrid molecules. From that intermediate form of reverse transcription, the resulting labelled cDNAs were obtained and were shown to be homologous to different drosophila "copia-like" transposable elements. These results suggest that most of the "copia-like" transposable elements were amplified through a reverse transcription pathway in Drosophila melanogaster.

Animals↗
PubMed1990

Development of an immunoenzymometric assay for alpha 1-microglobulin and measurement of its serum concentration in normal and HIV-infected persons.

alpha 1-Microglobulin was purified from urine to a purity of 97.7% in a yield of 25.8%, and was used to produce antibodies in sheep. These antibodies, purified by affinity chromatography, were used to develop a rapid one-step and a two-step immunoenzymometric assay (IEMA). The equilibrium in the reaction between solid phase-adsorbed antibodies and antigen and between the antigen and enzyme-labelled antibodies was attained within 30 and 100 min, respectively. The one-step IEMA permits a good differentiation of low alpha 1-microglobulin concentrations after 30 min reaction time. Its detection limit is 0.35 micrograms/l, and its measurement range is between 0.5 and 100 micrograms/l. The IEMA correlates well with radial immunodiffusion (r = 0.973). The mean alpha 1-microglobulin serum concentration in women is insignificantly lower (33.2 mg/l) than in men (36.1 mg/l). In both sexes the alpha 1-microglobulin concentration increases with age. HIV-infected symptomless men have a significantly lower (15.9 mg/l) alpha 1-microglobulin concentration in serum than normal persons, whereas in AIDS patients it is significantly higher (45.5 mg/l).

Acquired Immunodeficiency Syndrome↗
PubMed1990

[IgA nephropathy (Berger's disease). Our experience in 78 cases].

We studied 78 patients with a diagnosis of IgA nephropathy. Renal biopsy was indicated in 69 patients by the presence of macroscopic hematuria (52%), microhematuria or proteinuria (22%), nephrotic syndrome (10%), severe hypertension with microhematuria or renal failure (14%) or nephritic syndrome (1%). Nine were healthy subjects being studied as live kidney donors. An association with IgG and/or IgM was present in 92% of patients. Serum IgA was elevated in 36% of patients. Hypertension was present in 30% and decreased renal function in 29%. Patients with serum creatinine above 1.5 mg/dl tended to be older (33.8 vs 28.7 years) and to have hypertension (52% vs 19%). Among 25 patients followed for more than 12 months renal function remained stable in 44%, deteriorated in 20% and 36% developed renal failure. The latter was associated to older age, hypertension, absence of macroscopic hematuria and nephrotic syndrome. The 9 live donors had no clinical manifestations of renal disease. Thus, IgA nephropathy is a highly variable clinical entity, both in its manifestations and its prognosis. An asymptomatic course is demonstrated in some subjects.

Adolescent↗
PubMed1990

[Double blind biometric study on postoperative effects of analgesics].

A double blind trial to study the effects of analgetics was carried out in patients suffering from pain after third molar osteotomy. 204 patients were evaluated after random allocation to treatment with paracetamol 500 mg and paracetamol 500 mg plus codeine 30 mg. Statistical evaluation revealed a tendency for better analgesia using the combination of paracetamol and codeine. For further studies an exact stratification for sex and age is necessary. Sample sizes of 150 patients are necessary for each parameter.

Acetaminophen↗
PubMed1989

Alpha 1-adrenergic stimulation causes Mg2+ release from perfused rat liver.

The possibility that Mg2+ mobilization is stimulated in perfused liver by alpha 1-adrenergic agonists was studied by measuring Mg2+ release in response to 0.5 and 20 microM phenylephrine. During preperfusion exogenous Mg2+ was added to the medium to give 1.2 mM. 5 min before starting the addition of phenylephrine the infusion of exogenous Mg2+ was stopped. Mg2+ in the perfusate leaving the liver was measured by atomic absorption spectroscopy. Analysis of the Mg2+ decay curves with two exponential models indicated that phenylephrine caused dose-dependent Mg2+ release from perfused rat livers.

Animals↗
PubMed1989

Melanotic neuroectodermal tumor of infancy: report of two cases.

Melanotic neuroectodermal tumor of childhood is a rare lesion, but its presentation appears to be quite characteristic and a clinical diagnosis may be made with some confidence. Although this is an extremely rapidly growing, aggressive tumor, local excision appears to be adequate for cure.

Dentigerous Cyst↗
PubMed1989

The effect of subliminal oedipal and competitive stimulation on dart throwing: another miss.

Silverman and his associates have reported that subliminal presentation of oedipally relevant competitive stimuli can modify dart-throwing performance in male subjects. This study replicated their paradigm, but also examined the effects on performance of nonoedipal competitive stimuli. Our results failed to support Silverman's. Both types of subliminally presented competitive stimuli failed to have any systematic effect on dart-throwing performance.

Adolescent↗
PubMed1989

Acute radiodermatitis from occupational exposure to iridium 192.

Industrial radiography using the man-made radioisotope iridium 129 is commonplace in the southern states. Despite established procedures and safeguards, accidental exposure may result in typical acute radiodermatitis. We have presented a clinical example of this phenomenon.

Acute Disease↗
PubMed1989

Oral hairy leukoplakia: observations in 95 cases and review of the literature.

Oral hairy leukoplakia (HL) was observed in 25.4% of 373 HIV-seropositive patients (n = 95). 87 were men of an average age of 37.1 yr, 8 were women (30.3 yr). 71.6% of the patients were male homosexuals. At initial diagnosis of HL the majority of cases was classified as CDC IVc1 (45.3%) and CDC II (22.1%). Average CD4/CD8 ratio (n = 19) was 0.24 with a range of 0.04-1.0. Thirty biopsies of HL revealed some of the histologic features thought to be characteristic. In only 20 of 30 biopsies EB-virus-specific-capsid antigen was detected. The problems of clinical and histological diagnosis of HL are discussed. Further strict criteria are necessary in order to define HL more distinctly.

Adult↗
PubMed1989

Yeast Hsp70 RNA levels vary in response to the physiological status of the cell.

Yeast Hsp70 genes constitute a multigene family in which at least five of the nine members are heat inducible. Hsp70 RNA levels also vary dramatically during stationary arrest and sporulation. During growth to stationary phase, SSB1-SSB2 and SSC1 RNAs decreased in abundance as cell density increased. In contrast, SSA1-SSA2 RNA levels increased before the diauxic shift and then decreased as cells approach stationary phase. SSA3 RNA was detected only after the diauxic shift and accumulated to high levels as cells entered stationary phase. This accumulation was reversed by addition of glucose. Studies with cyr1 mutants indicated that SSA3 RNA accumulation is stimulated by decreasing intracellular cyclic AMP concentrations. When cells were incubated in sporulation medium, most Hsp70 RNAs, with the exception of SSA1-SSA2 RNA, decreased in abundance. This finding contrasted with the SSA1-SSA2 pattern observed during growth to stationary phase. SSA3 RNA was not detected during growth in acetate-based medium but accumulated after several hours. SSA3 RNA accumulation was higher in sporulating cells than in nonsporulating cells and was reversed by addition of glucose.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1989

Changes in plasma epinephrine concentration after dental infiltration anesthesia with different doses of epinephrine.

To define the cardiovascular risk as a result of epinephrine in local anesthetic solutions used in dental anesthesia, we measured the plasma epinephrine levels, the mean arterial brachial pressure (MAP), and heart rate for 15 min, after infiltration anesthesia in the area buccal to the upper permanent left lateral incisor and canine. For this purpose, 12 dental student volunteers received 2.0 mL 2% lidocaine with and without 20 or 80 micrograms epinephrine, in a double-blind cross-over trial. --Plain lidocaine solution cause no significant changes in the parameters under study when compared with the baseline values. --Lidocaine with 20 micrograms epinephrine caused a sustained doubling of the plasma epinephrine concentration two min after injection, and at the same time, a slight but significant (p less than 0.05) decrease in MAP. Two min and 45 s after injection, the heart rate increased by four beats/min when compared with the baseline rate. --Lidocaine with 80 micrograms epinephrine caused a doubling of the basal plasma epinephrine value as early as one min and 25 s after injection, and a ten-fold increase above the basal value at the end of the observation period (15 min). The heart rate increased significantly (p less than 0.01) by five beats/min above the baseline value starting two min after injection, and rose to a maximum of 13 beats/min until the end of the observation period. The time-point of the decrease in MAP was earlier, but the amount of the decrease equaled that measured after submucosal injection of 20 micrograms epinephrine with 40 mg lidocaine.

Adult↗