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J Becker

Publications and source records attributed to J Becker.

At least 253 records · Page 14Linked to original sources
PubMed1987

HPV DNA detection in tumours of the head and neck: a comparative light microscopy and DNA hybridization study.

A series of 22 squamous cell carcinomas (4 cases grade 1; 11 cases grade 2; 7 cases grade 3) of the oral cavity (13 cases), (naso-)pharynx (5 cases) and larynx (4 cases) were studied by conventional light microscopy and filter (dot blot) hybridization for the detection of human papillomavirus (HPV) DNA. In 4 carcinomas, tumour-free tissue from the resection margins of the surgical sample was examined in addition to the tumour specimen. The same kind of investigation was carried out on 4 oral leukoplakias without dysplasia. All cases were thoroughly examined for HPV-associated cytopathic effects (koilocytosis). In all cases, material was obtained for DNA extraction followed by dot blot hybridization. DNA hybridization was carried out under stringent conditions with mixed probes of HPV 6/11 as well as HPV 16/18. Koilocytosis was observed in 10/22 carcinomas (45%, 4/4 G1 tumours, 6/11 G2 tumours, none out of 7 G3 tumours) and 3/4 leukoplakias. Koilocytosis always occurred at the tumour surface or the surface epithelium immediately adjacent to the tumour. HPV DNA was found in 8/22 carcinomas (36%, 2/4 G1 tumours, 5/11 G2 tumours, 1/7 G3 tumours). We observed HPV 16/18 infections in 3 cases and HPV 6/11 infection in 1 case. The other 4 cases were positive under relaxed conditions and, thus, could not be grouped into one of the examined types of HPV infections. In 4 carcinoma cases, tumour tissues and resection margins were examined. 3/4 cases showed concordant findings, i.e. in 2 cases tumour tissue and tumour-free mucosa (1-2 cm distant to the tumour) were positive for HPV, 1 case was negative in both samples. In 6/8 cases positive for HPV, HPV DNA detection corresponded to the observation of intensive koilocytosis. The leukoplakias were seen to harbour HPV DNA in 3 cases (1 case: HPV 6/11; 1 case: HPV 16/18; 1 case: positive under relaxed conditions). We did not observe HPV DNA in normal mucosal tissues. Our findings provide further evidence for the presence of HPV infections in tumours of the upper respiratory and digestive tract. Prospective studies now have to clarify the biological importance of HPV infections in this group of human cancer.

Adult↗
PubMed1987

Electroencephalographic characteristics of children with learning disabilities.

Normal, borderline and abnormal EEG findings were investigated in 122 children with no evidence of active neurological or psychiatric disorder, or perceptual or behavioral alterations. All children had a normal IQ. Sixty-one children had a good academic achievement (Controls) and 61 were considered as learning disabled (LD). The great majority of the children had pathological antecedents considered as risk factors for brain damage. The main findings observed were: Abnormal signs were significantly more frequent in LD than in control children. Atypical high amplitude alpha, and abnormal focal paroxysmal and nonparoxysmal activities were found only in LD children with risk factors. No significant differences in the resting EEG were found between presence or absence of pathological antecedents, or between males and females, when the children were compared as a group against the 4 EEG categories. Paroxysmal reactivity to eye-closure was only observed in children with a pathological history. Excessive response to hyperventilation (Grades II and III) was found significantly more frequently in girls than in boys.

Brain Damage, Chronic↗
PubMed1987

Foot care.

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Foot Diseases↗
PubMed1986

1731, a new retrotransposon with hormone modulated expression.

We report here the characterisation of 1731, a new copia-like element of Drosophila melanogaster. 1731 was first isolated in a screening for ecdysterone modulated genes. This element is about 4.6 Kb long and is flanked by two long terminal repeats (LTRs) 336 base pairs in length. The whole 1731 element is transcribed into polyA+ RNAs, and these transcripts decrease rapidly upon hormonal treatment. 1731 is moderately repeated in the fly genome and slightly amplified in Kc/cells where extrachromosomal circular forms are found. The LTRs were sequenced in one cloned copy of 1731 and show a structural organisation similar to that of several other copia-like elements and retroviral proviruses. Small nucleotide stretches, similar to those found in Mouse Mammary Tumor Virus LTRs and known to be important in its regulation by a steroid hormone, occur in 1731 LTRs.

Animals↗
PubMed1986

A rapid radiometric assay for measuring phagocytosis of Saccharomyces cerevisiae in macrophage cultures.

A new assay was developed to measure yeast phagocytosis in cultures of murine resident peritoneal macrophages. Saccharomyces cerevisiae was radiolabeled during exponential growth in nutrient broth supplemented with [3H]glucose. Following ingestion of the radiolabeled heat-killed yeast particles for 15 min, phagocytic capacities were measured in harvested macrophage lysates by liquid scintillation spectrometry. The new procedure compares favorably with light microscopic techniques and appears to be a more sensitive method for quantitating phagocytic function. Dose-response studies indicate, that over a wide range of dexamethasone concentrations, the radiometric procedure consistently measures greater inhibitory effects for the steroid induced suppression of phagocytosis.

Animals↗
PubMed1986

Immunofluorescent localization of type-V collagen as a fibrillar component of the interstitial connective tissue of human oral mucosa, artery and liver.

Polyclonal antibodies against native human type-V collagen were produced in rabbits and goats. Following purification, crossreaction of the antibodies with highly immunogenic peptides of basement membranes or the interstitial matrix was excluded on the basis of sensitive radioimmunoassays. These antibodies, when applied to cryostat sections of human oral mucosa, liver and arterial walls, never stained basement membranes as did antibodies against type-IV collagen or laminin. On the contrary, we observed delicate arborizing fibers in the interstitial compartment with extensions contacting structures such as subepidermal basement membranes. Arterioles contained a unilamellar sheath of longitudinally oriented fibers limited to the intimal layer. Larger arteries exhibited a multilamellar fibrous fluorescence over the whole intima, whereas the media showed a much weaker staining. The data identified type-V collagen as an interstitial fibrillar collagen rather than a basement membrane collagen, with a tissue pattern completely different from that of collagens types I, III, VI or fibronectin. A reinterpretation of the role of type-V collagen in connective tissue function is warranted.

Antibody Specificity↗
PubMed1986

Social support as a multifaceted concept: examination of important dimensions for adjustment.

Four commonly used operationalizations of the social support concept: network contact frequency, satisfaction with support (including nine dimensions), perceived availability of support, and use of support, were related to two measures of psychological adjustment (Beck Depression Inventory and Symptom Checklist-90) and to one measure of physical adjustment (Cornell Medical Index). Subjects were 68 45- to 85-year-old, highly stressed care-givers to spouses with Alzheimer's disease. Results indicate that of the four operationalizations, Satisfaction with Support was the only significant predictor of depression and general psychopathology. The set of four support variables showed the strongest relationship to depression level, next strongest to general psychopathology, and least to physical health. The satisfaction with nine social support dimensions related differentially to the types of adjustment. Results suggest the importance of specificity (sample, support operationalization, dimensions, adjustment measures) in social support research.

Adaptation, Psychological↗
PubMed1986

The immunohistochemical distribution of collagens type IV, V, VI and of laminin in the human oral mucosa.

The distribution of collagens type V (form AB2) and VI was investigated on cryostat sections of normal human oral mucosa by indirect immunofluorescence. For comparison, antibodies to fragments of type IV collagen and laminin were also used to delineate basement membrane containing structures. All antibodies used were raised against human proteins. Type V collagen appeared as a microfibrillar structure throughout the interstitium, apparently touching but not being present within epithelial or vascular basement membranes. Microfibrils in blood vessel walls were limited to the intimal layer. Pericellular areas were not specifically stained. Type VI collagen appeared as an almost amorphous stromal structure becoming more prominent and more fibrillar in the upper connective tissue papillae. Intense staining was observed in the media of blood vessels and around smooth muscle cells. A possible role of type VI collagen in tissue stabilization may be expected from this ubiquitous and abundant distribution. The findings identify types V and VI collagen as important structures in the oral mucosa and serve as a basis for understanding morbid changes.

Antibody Specificity↗
PubMed1986

[Effect of subpartal tocolysis on maternal cardiovascular parameters with subsequent cesarean section in general anesthesia].

The influence of subpartal beta-sympathicomimetic tocolysis on a subsequent Caesarean section with halothane as inhalational anaesthetic was examined in 42 pregnant women. Alterations in the heart rate, blood pressure and heart action during the operation were measured. 23 patients (group "bolus") received fenoterol monotherapy. In 19 patients (group "iv-tocolysis") fenoterol was combined with the cardioselective beta-1-blocking agent metoprolol. In comparison with these two groups, 25 pregnant women without tocolysis were examined as controls. There were only slight differences in heart rate and blood pressure between the three groups. Arrhythmias were registered in 42 percent of the cases, in most cases during light anaesthesia before delivery. Sinus tachycardias with a heart rate of 130 beats per minute or more were observed most frequently. Arrhythmias of ectopic origin and sinus bradycardias, however, were found seldom. The incidence of arrhythmias in the three groups during Caesarean section did not differ significantly. There was no evidence for an increased occurrence of arrhythmias following beta-sympathicomimetic tocolysis.

Adult↗
PubMed1986

Prevalence of dental caries and Streptococcus mutans in Meo of Northern Thailand.

The prevalence of dental caries was studied in 505 Meo, a minority of Northern Thailand, using the DMFT index. Plaque material from all patients was examined qualitatively for S. mutans. The DMFT (dmft) index score ranged between 1.69 and 7.06 with a mean of 2.17 +/- 3.24 for men and 3.45 +/- 3.72 for women. There was a statistical difference in caries prevalence between males and females (P less than 0.05). There was no statistical correlation between miang chewing and caries prevalence. Fluoride concentration of water samples was between 0.043 and 0.077 ppm F-. Of 505 plaque samples, 13.3% were positive for S. mutans, mostly of biotype I. Compared to other Northern Thai hill tribes and the Thai rural population, the Meo appear to have a higher dental caries prevalence rate.

Adolescent↗
PubMed1986

Inhibition of macrophage phagocytosis by Bacteroides fragilis in vivo and in vitro.

A number of investigators have provided experimental evidence for synergistic effects in mixed infections with Escherichia coli and Bacteroides fragilis. In vitro studies have suggested that competition for serum opsonins and diminished subsequent phagocytosis by polymorphonuclear leukocytes might explain these effects. In the present study we evaluated the effect of B. fragilis on macrophage phagocytosis. It was shown that peritoneal macrophages from mice injected intravenously 6 to 12 h earlier with 10(8) CFU of encapsulated B. fragilis were markedly suppressed in their phagocytic ability. Injections of laboratory-passaged, less-encapsulated B. fragilis, other bacteria, or latex particles were either not suppressive of macrophage phagocytosis or less effective. When peritoneal macrophages were treated in vitro for 24 h with the same challenge organisms prior to assessing their phagocytic capacity, encapsulated B. fragilis also proved significantly more suppressive than challenges with other organisms or latex particles. We conclude that suppression of macrophage phagocytosis by B. fragilis seems to be an important mechanism contributing to synergistic effects described for mixed aerobic and anaerobic infections.

Animals↗
PubMed1986

Immunohistochemical distribution of collagens types IV, V, and VI and of pro-collagens types I and III in human alveolar bone and dentine.

The aim of the present study was to characterize the composition of the organic matrix in alveolar jaw bone and dentine using antibodies against pro-collagens Types I and III and collagens Types IV, V, and VI. After demineralization of oral hard tissues in 0.2 N HCl, antigenicity was well preserved and the distribution of the pro-collagens and collagens could be demonstrated. Staining for pro-collagen Type I was prominent around osteoblasts and in pre-dentine, indicating active de novo synthesis of Type I pro-collagen. Pro-collagen Type I was ubiquitous but was less abundant in bone and dentine, whereas pro-collagen Type III was seen only in areas of bone remodeling, in peritubular spaces, and in pre-dentine. Type IV collagen was limited to the basement membranes of vessels in osteons and bone marrow. Type V collagen was detected neither in pre-dentine nor in bone. In contrast, Type VI collagen was found in dentine and bone, showing a faint but homogeneous staining which, similarly to pro-collagen Type III, was pronounced around osteoblasts and in pre-dentine, areas of active bone and dentine formation. This study showed that the organic matrix of dentine and bone contains Type VI as well as Type I collagen. Pro-collagen Type III (and to a lesser extent collagen Type VI) is transiently produced during new formation and remodeling of oral hard tissues, and disappears once the matrix calcifies. Type I pro-collagen qualifies as a general marker protein for increased osteoblastic activity. We conclude that immunostaining for the different collagen/pro-collagen types can be used to assess normal or abnormal stages of bone/dentine formation.

Adolescent↗
PubMed1986

Dream content after using visual inverting prisms.

All night sleep electroencephalograms were recorded in 10 healthy adults for 2 nights. On the second night all subjects were requested to be at the laboratory 5 hr. before their usual bedtime and were submitted to the same routine for performance on several visuomotor tasks; experimental subjects were required to use visual inverting prisms upon their arrival and during the performance of the tasks. Subjects were awakened 10 min. after each paradoxical sleep episode for dream collection. Dream content was significantly affected by the use of the inverting prisms: the presleep tasks and day-time activities were more frequently incorporated into the dreams of the experimental subjects. The dreams of the experimental group were more active and vividness was evaluated as lower by them than by the control subjects.

Adaptation, Psychological↗
PubMed1985

The hepatic response to Ca2+ is inhibited by Mg2+ and enhanced by phenylephrine or ouabain.

Net hepatic Ca2+ efflux, K+ uptake and glycogen breakdown in response to the alpha 1-adrenergic agonist phenylephrine were studied. Rat livers were perfused with CO2/bicarbonate-buffered solutions containing 10 microM Ca2+ and different amounts of Mg2+. K+-free medium and/or ouabain were used to block (Na+ + K+)-ATPase-dependent K+ uptake. In some experiments a sharp increase in extracellular Ca2+ concentrations was produced by infusing CaCl2 into the medium entering the liver. Perfusion with K+-free medium and ouabain enhanced the phenylephrine-induced Ca2+ efflux and diminished the glycogenolytic response, indicating a dissociation of Ca2+ release and glycogenolysis. Exogenous Ca2+ had practically no effect if livers were perfused with regular medium containing 1.2 mM Mg2+. In the presence of phenylephrine and if extracellular Mg2+ concentrations were lowered by omitting Mg2+ from the medium or by preperfusion with EGTA, exogenous Ca2+ was glycogenolytically effective and also produced a transient K+ uptake. Increased extracellular concentrations of Mg2+ inhibited the effects of exogenous Ca2+. In the presence of phenylephrine, higher concentrations of Mg2+ were needed than in the absence of alpha 1-adrenergic agonist to achieve a similar degree of inhibition. In one respect ouabain effects were comparable to those of phenylephrine: the glycoside also increased the metabolic response to exogenous Ca2+ and diminished the sensitivity towards Mg2+. Phenylephrine and ouabain may both enhance the permeability of plasma membranes for Ca2+.

Animals↗
PubMed1985

Quantitative analysis of immunocompetent cells in human normal oral and uterine cervical mucosa, oral papillomas and leukoplakias.

Using monoclonal antibodies reacting with T-cell subpopulations, Langerhans cells and macrophages, the number and distribution of cells of the immune system in normal oral and cervical mucosa was determined and statistically compared with that in oral papillomas and oral leukoplakias. Increased numbers of labelled cells were found in oral leukoplakias and particularly in oral papillomas. In the epithelium of all specimens, Langerhans cells and T-lymphocytes of the suppressor/cytotoxic phenotype as well as of the helper phenotype were seen. Suppressor/cytotoxic and helper T-lymphocytes were in equal numbers in the epithelium of oral papillomas, but were about 2:1 in all other lesions. In normal oral epithelium, macrophages were rare but were in greater numbers in leukoplakias and papillomas. In the connective tissue of all lesions, more labelled cells were present than in epithelium with T-lymphocytes predominant. Although Langerhans cells were rare in connective tissue, many were seen in oral papillomas.

Antibodies, Monoclonal↗