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Biomedical subjects

B Becker

Publications and source records attributed to B Becker.

At least 37 records · Page 2Linked to original sources
PubMed1989

Tumorigenicity testing of various cell substrates for production of biologicals.

The data presented in this paper confirm earlier findings that the antithymocyte globulin (ATG) treated newborn Wistar rat is more sensitive than the nude mouse in allowing the metastatic potential of a cell substrate to be displayed. Several human neoplastic cell lines such as HeLa, FL, Hep-2, KB and WiDr cells as well as monkey kidney cell lines such as Vero and BSC-1 cells, which failed to metastasize in nude mice, formed metastases in ATG-treated newborn rats. Earlier studies on the tumorigenicity of Vero monkey kidney cells were extended to various passage levels of BSC-1 aneuploid and CV-1 diploid monkey kidney cells in order to establish the effect of prolonged in vitro culture on the oncogenic potential of African green monkey kidney cells. It was found that BSC-1 and CV-1 cells--like Vero cells--showed increased tumorigenicity in the rat model with increasing cell passage. Cells of all three cell lines passaged 146 to 257 times formed invasive adenocarcinomas in the muscle (inoculation site) of the animals. Considering the passage levels, at which the adenocarcinomas appeared and lung metastases were detected, the malignant potential was most pronounced in CV-1 cells, followed by Vero cells and was lowest in BSC-1 cells. Results obtained from the in vitro tumorigenicity assay of cell colony formation in soft agar confirmed the rat test results: increased cell passage of all three monkey kidney cell lines resulted in higher cell colony formation. The in vitro chick embryo skin culture assay was found unsuitable for the differentiation of various passage levels of these cell lines.

Animals↗
PubMed1988

Intraocular pressure response to topical dexamethasone as a predictor for the development of primary open-angle glaucoma.

In a retrospective study we reviewed the records of 788 subjects who had been corticosteroid tested with 0.1% dexamethasone four times daily to one eye for six weeks. All subjects had normal kinetic visual fields and optic nerve heads in both eyes at the time of testing and were followed up for a minimum of five years. Some subjects had normal baseline intraocular pressures whereas others were considered to have ocular hypertension. Of 276 individuals who were high corticosteroid responders (intraocular pressure greater than 31 mm Hg during dexamethasone administration), 36 (13.0%) developed glaucomatous visual field loss during the follow-up period. Only nine of 261 individuals (3.4%) who were intermediate responders (intraocular pressure 20 to 31 mm Hg during dexamethasone administration) and none of 251 individuals who were low responders (intraocular pressure less than 20 mm Hg during dexamethasone administration) developed glaucomatous visual field loss. However, the ability of the intraocular pressure response to dexamethasone to predict the development of glaucomatous visual field loss was not as good as the predictive power of a multivariate model that included patient age, race, baseline intraocular pressure, baseline outflow facility, baseline cup/disk ratio, and systemic hypertension.

Adult↗
PubMed1988

A comparison of viruses infecting two different Chlorella-like green algae.

Five plaque-forming viruses (Pbi viruses) of the unicellular, eukaryotic, exsymbiotic Chlorella-like green alga strain Pbi were isolated from fresh water collected in Germany. The viruses were compared to two previously characterized plaque-forming viruses (NC64A viruses) of Chlorella strain NC64A. The Pbi viruses do not infect Chlorella NC64A and vice versa. Like the NC64A viruses the Pbi viruses are large polyhedron with a diameter of 140 to 150 nm, are chloroform sensitive, have many structural proteins, and have large dsDNA genomes of at least 300 kb. However, the Pbi viruses are serologically distinct from the NC64A viruses. The five Pbi virus genomes contain 5-methylcytosine, which varied from 14.2 to 43.1% of the cytosine, and two of them also contained N6-methyladenine. DNAs from the Pbi viruses hybridized poorly with the two NC64A virus DNAs and they have a higher guanine plus cytosine content (ca. 46%) than the NC64A virus DNAs (ca. 40%).

Base Composition↗
PubMed1987

Object relations ego deficits in bulimic college women.

Two types of bulimic (purging and restricting) and two types of non-bulimic (binging or normal) eating patterns were reported by 547 undergraduate women who also were assessed for ego function deficits on the four subscales of the Bell Object Relations Inventory. As predicted by psychoanalytic theory, the two bulimic subgroups appeared significantly more pathological on the Insecure Attachment subscale, which identifies ambivalent interpersonal relations and fear of object loss. When the four groups were ranked according to severity of type of eating disorder, a linear increase in group means and in the proportion of high scoring subjects was found on Insecure Attachment and also on the Egocentricity subscale, which indicates suspicious and manipulative attitudes toward others. Results are interpreted to support theories that relate eating disorders to disturbances in object relations ego functioning.

Adolescent↗
PubMed1986

A scale for the assessment of object relations: reliability, validity, and factorial invariance.

Factor analysis of the Bell Object Relations Inventory items produced four subscales interpreted to be underlying dimensions of object relations. Replication factor analysis confirmed the factor structure. Subscales had high internal consistency and were free of age, sex, or social desirability response bias. Subscales had low intercorrelations with Brief Psychiatric Rating Scale (BPRS) sum scores, Global Assessment Scale scores, and most BPRS symptoms. Subscales appear to represent common features of personality and to sample a domain that is distinct from symptomatology, but related to variations in psychopathology. Percentage of high scoring subjects and subscale mean values are compared for seven criterion groups. High scores were least frequent among community active adults and most frequent among borderlines. Selected findings from the group comparisons are discussed to illustrate the potential of the instrument for empirical examination of theoretical assumptions about the object relations ego function and its components.

Adult↗
PubMed1986

In vitro studies on steroid metabolism by gonadal tissues from ambisexual teleosts. II. Conversion of [14C]androstenedione by the heterologous gonadal tissues of the protandric sea bream Pagellus acarne (Risso).

The heterologous gonadal tissues of the protandric sea bream Pagellus acarne were incubated with [14C]androstenedione in vitro. The tissues were taken from two males, an inverting specimen, and a female in early April. Although the testicular tissue regresses in the inverting fish the rate of 11 beta-hydroxylation in the male part of the gonad is at least as high as in the homologous portion of the "pure" male. No difference was found in the enzymatic pattern between the ovarian part of the inverting animal and that of the female. There is, however, a striking distinction in the metabolic activities of the pooled ovarian parts from two males and the homologous tissues from the inverting and female animals. They concern mainly the activities of 11 beta-hydroxylase and 17 beta-HSD. Moreover, ring A-reduction and the ratio of 5 alpha/5 beta-reduced metabolites differ considerably from the corresponding gonadal tissues taken from the inverting and the female specimen. The possible physiological meaning of these findings remains to be elucidated.

Animals↗
PubMed1986

Neuropsychological consultation in psychiatric practice.

A specialty area with historical roots in behavioral neurology as well as experimental and clinical psychology, clinical neuropsychology offers a unique contribution to psychiatric practice in the form of consultation regarding cognitive, perceptual, and motor functioning. Using quantified, standardized, and repeatable measures, this comprehensive assessment can be helpful in identifying cortical dysfunction, in measuring decline or recovery, and in assessing response to treatment.

Alcoholism↗
PubMed1985

The significance of thermotolerance after 41 degrees C hyperthermia: in vivo and in vitro tumor and normal tissue investigations.

We have investigated the development of thermotolerance in both tumors and normal tissues after 41 degrees C for durations as brief as 15 minutes. The murine RIF tumor, treated by both local radiofrequency and systemic methods, was assayed for thermotolerance by both tumor growth and cell survival analyses. The murine leg and ear, treated by conductive methods, were assayed using pre-defined tissue damage scoring systems. All of these treatments quickly induced substantial levels of thermotolerance. In the tumor studies using local heating, RIF mean diameter doubling time decreased from 17.8 days to a minimum of 13.0 days with a 9 hr interval between 41.0 degrees C for 15 minutes and 44.0 degrees C for 30 minutes (9 hr D1-D2); cell survival increased from 1.2 X 10(-2) to 3.4 X 10(-1) (same interval). Both assays showed some degree of tolerance present immediately after 41.0 degrees C for 15, 30 or 60 minutes (0 hr D1-D2). In the tumor studies using systemic heating, the kinetic pattern of the induced tolerance was similar to that observed after local heating. In the leg studies, 41.0 degrees for 30 minutes increased the time at 45 degrees C necessary to induce a specified level of tissue damage (mean score of 7) by a maximum of 1.8 times (24 hr D1-D2). The kinetic pattern was similar to that for the tumors. In the ear studies, 41.0 degrees C for 30 minutes increased the time at 45 degrees C necessary to induce ear necrosis in 50% of animals by a maximum of 3.5 times (48 hr D1-D2). The peak tolerance level occurred later for the ears, which have a lower normal temperature of 28-30 degrees C, than for the tumors or legs. These results indicate that: thermotolerance can begin to appear in tumors during treatment if hyperthermia sessions involve initial low thermal exposures (near 41 degrees C) for 15 minutes or longer; thermotolerance can develop in tumors after systemic heating and occurs with a kinetic pattern similar to that following local heating; and normal tissues also can develop high levels of thermotolerance after similar thermal exposures.

Animals↗
PubMed1985

Neurologic, neuropsychologic, and computed cranial tomography scan abnormalities in 2- to 10-year survivors of small-cell lung cancer.

In order to evaluate the relationship between neurologic function and cranial irradiation, 20 patients treated on National Cancer Institute (NCI) small-cell lung cancer (SCLC) trials who were alive and free of cancer 2.4 to 10.6 years (median, 6.2) from the start of therapy were studied. All were tested with a neurologic history and examination, mental status examination, neuropsychologic testing, and review of serial computed cranial tomography (CCT) scans. Fifteen patients had been treated with prophylactic cranial irradiation (PCI), two patients with therapeutic cranial irradiation, and three received no cranial irradiation. All patients but one were ambulatory and none were institutionalized. Fifteen patients (75%) had neurologic complaints, 13 (65%) had abnormal neurologic examinations, 12 (60%) had abnormal mental status examinations, 13 (65%) had abnormal neuropsychologic testing, and 15 (75%) had abnormal CCT scans. Compared with those given low-dose maintenance chemotherapy during PCI using 200 to 300 rad per fraction, patients who were given high-dose induction chemotherapy during the time of cranial irradiation or large radiotherapy fractions (400 rad) were more likely to have abnormal mental status examinations (6/6 v 4/9) and abnormal neuropsychologic tests (6/6 v 4/9), but no major difference in CCT findings was present. CCT scans in the majority of cases (11/18) showed progressive ventricular dilatation or cerebral atrophy up to 8 years after stopping therapy. We conclude neurologic abnormalities are common in long-term survivors of SCLC, and may be more prominent in patients given high-dose chemotherapy during cranial irradiation or treated with large radiotherapy fractions. The CCT scan abnormalities are common and progressive years after prophylactic cranial irradiation and chemotherapy are stopped.

Adult↗
PubMed1985

Patients with small-cell lung cancer treated with combination chemotherapy with or without irradiation. Data on potential cures, chronic toxicities, and late relapses after a five- to eleven-year follow-up.

We assessed the outcome in 252 patients with small-cell lung cancer 5 to 11 years after treatment with combination chemotherapy, with or without chest and cranial irradiation, in National Cancer Institute therapeutic trials from 1973 through 1978. Twenty-eight patients (11%) survived free of cancer for 30 months or more. Fourteen patients remain alive without evidence of cancer beyond 5 years (range, 6.4 to 11.3 years), and 7 patients have returned to a lifestyle similar to that before diagnosis. The other 14 patients who were cancer-free at 30 months have developed cancer or died; 6 patients had a relapse, 4 developed or died from non-small-cell lung cancer, and 4 died of unrelated causes. A few patients with small-cell lung cancer (5.6%) may be cured. Thirty-month, cancer-free survival is insufficient to show a cure. Although late toxicities are troublesome, they do not outweigh the benefits of prolonged survival and potential for cure with modern aggressive therapy in small-cell lung cancer.

Adult↗
PubMed1985

Cellular sensitivity to glucocorticoids in patients with POAG. Steroid receptors and responses in cultured skin fibroblasts.

The question of a generalized hypersensitivity to corticosteroids in primary open-angle glaucoma (POAG) was investigated using cultured skin fibroblasts from patients with POAG and age-matched controls. Nuclear binding of (3H)-dexamethasone was performed to evaluate possible changes in the glucocorticoid receptors. Cortisol effects on (3H)-thymidine uptake into the cells were investigated as a measure of the cellular sensitivity to corticosteroids. When POAG and control groups were compared, no significant differences (P less than 0.05) were found for either the number or affinity of glucocorticoid receptors (POAG: Kd = 6.1 +/- 1.0 nM, Rt = 94 +/- 13 sites/cell X 10(3); control: Kd = 5.5 +/- 1.6 nM, Rt = 124 +/- 20 X 10(3) sites/cell) or for cortisol effects on thymidine uptake (POAG: C50 = 83 +/- 38 nM; control: C50 = 80 +/- 34 nM). Use of epidermal growth factor (EGF) resulted in an increased steroid sensitivity in some cell lines, but again no differences between POAG and control groups were detected. These results suggest that a generalized cellular hypersensitivity to glucocorticoids is not intrinsic to POAG. It is possible that environmental alterations and/or endogenous factors may influence the steroid responses observed in these patients.

Adult↗
PubMed1985

Maturation of Rb+ and PAH accumulation by rabbit anterior uvea and choroid plexus.

In vitro accumulation of radioactive para-aminohippuric acid (3H-PAH) and rubidium (86Rb+) by the anterior uvea, ciliary processes, and the choroid plexus was evaluated in tissues from newborn and various aged rabbits. Accumulation of PAH was present in the anterior uvea at 1 day of age (tissue to media ratio, T/M, of 2.1 +/- 0.2) and remained at this level for the first 14 days of life. Accumulation did not rise to adult levels until 21 days of age (T/M 5.5 +/- 0.6). Rubidium accumulation in the anterior uvea, a measure of Na+, K+-pump activity, was higher than adult values 6 hr after birth (T/M25.2 +/- 0.9). Activity remained elevated through day 28 and did not fall to adult levels until day 60 (T/M 13.4 +/- 0.6). Accumulation studies on isolated ciliary processes were similar to those obtained from anterior uveal tissue. Daily subcutaneous injections of penicillin (300,000 units/kg/day) for 1 week had no effect on anterior uvea PAH accumulation (penicillin T/M was 1.7 +/- 0.1 and saline control T/M was 2.0 +/- 0.2). Accumulation of either 3H-PAH or 86Rb+ by the choroid plexus was present 1 day after birth in amounts that were similar to adult values and did not change during the 90 days of testing.

Aminohippuric Acids↗
PubMed1984

Age-dependency of alpha- and beta-adrenoceptors on thrombocytes and lymphocytes of asthmatic and nonasthmatic children.

Among the possible mechanisms which may cause wheezing or asthmatic episodes a genetically determined beta-adrenoceptor blockade and a hyperresponsiveness of alpha-adrenoceptors has been postulated. Evidence to support this hypothesis stems from an increased bronchial sensitivity to beta-blockers, a reduced formation of cyclic AMP in response to beta-adrenergic stimulation and enhanced alpha-adrenergic responses in asthmatic subjects. The recent development of techniques for measuring the specific, high-affinity binding of radiolabeled alpha- and beta-adrenergic antagonists made it possible to study alpha- and beta-adrenoceptors in vitro. Based upon the assumption that a change in the number and/or affinity of adrenergic receptors might be a general phenomenon, we have performed alpha- and beta-receptor binding studies on lymphocytes and platelets from wheezing infants and asthmatic children as well as of infants, children, and adults not suffering from these diseases. Using 125[I]-cyanopindolol (ICYP) and 3[H]-yohimbine (HYOH) as highly specific ligands for alpha- and beta-adrenoceptors, the following results were obtained: Lymphocytes and platelets from control subjects and asthmatics bound similar amounts of ICYP and HYOH and thus showed no differences either in the number or the affinity of alpha- and beta-adrenoceptors. Lymphocytes and platelets of wheezing and nonwheezing infants also bound the same amounts of the radioligands. In asthmatic children receiving 4 X 2 puffs salbutamol beta-adrenoceptors were down-regulated and this may mimic beta-adrenoceptor blockade. When subjects were divided into four categories according to age (0-5, 5-10, 10-20 years, adults) the number of beta-adrenoceptor binding sites showed an age-dependent increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

In vitro studies on steroid metabolism by gonadal tissues from ambisexual teleosts. I. Conversion of [14C]testosterone by males and females of the protogynous wrasse Coris julis L.

Gonadal tissue of females, and primary and secondary males of the protogynous wrasse Coris julis were incubated with labeled [14C]testosterone. The large majority of metabolic products consisted of free, neutral steroids. Marked 11 beta-hydroxylation was restricted to testes from secondary males. 5 beta-Reduction of ring A was predominant in both types of males, whereas ovarian tissue from normal females produced a larger share of 5 alpha-androstanes. The metabolic products of ovaries from females that were injected with testosterone 7 days before incubation were similar to those of untreated females, although the ratio of 5 alpha/5 beta reduced steroids was changed toward the "male type".

Acetylation↗
PubMed1984

The dyskinetic cilia syndrome in childhood. Modifications of ultrastructural patterns.

The syndrome of cilia dyskinesia is known as a heterogenous ciliary dysfunction caused by morphological defects of the dynein arms, the nexin links, the radial spokes and by the transposition of microtubules. Supernumerary tubules have been regarded as acquired morphological defects on the background of other bronchopathies. The report of a 9-year-old girl with the clinical signs of ciliary dyskinesis is considered to be an attribution to the clinical and pathological features of this syndrome. The girl's history of chronic bronchopulmonary infections and nasal polyposis resistant to therapy made her suspected to be ill of Kartagener's syndrome. The results of ultrastructural investigations of the mucosa from ciliated epithelium revealed a ciliary structural defect in the bronchi as well as in the nose and the sinuses with supernumerary microtubular doublets and singles, a decentration of the central tubules and shortened dynein arms. The regularity of the electron optical abnormalities implicates a systemic disorder of ciliated epithelium, which is to be summarized to the syndrome of cilia dyskinesis.

Bronchi↗
PubMed1984

Central effects of thyrotropin-releasing hormone and arginine vasopressin on intraocular pressure in rabbits.

Administration of either thyrotropin-releasing hormone (TRH) or arginine vasopressin (a-VP) into the rabbit third ventricle elevated intraocular pressure (IOP). IOP was increased 3.6 mmHg 45 min after TRH (10 ng/0.1 ml) administration and increased 6.4 mmHg 45 min following delivery of a-VP (5 micrograms/0.1 ml). Outflow facility and episcleral venous pressure were not altered by either agent. Estimated aqueous humor flow 45 min after third ventricle administration was increased 66% after TRH and 91% after a-VP delivery. Posterior chamber aqueous humor ascorbate was reduced 60 min after TRH administration. Pretreatment with either systemic or topical atropine prevented the TRH or a-VP induced increase in IOP. Body temperature (BT), which was unaltered after TRH administration, was elevated by third ventricle delivery of a-VP. The a-VP induced increase in BT was blocked by systemic pretreatment with either indomethacin or atropine.

Animals↗
PubMed1984

[Pulmonary dysplasia in infancy. Pathogenesis, pneumologic course studies and therapy possibilities].

Some premature and mature newborns who require intermittent positive airway pressure (IPPV) and high oxygen concentrations for respiratory distress syndrome develop characteristic damage of bronchi and bronchioles termed broncho-pulmonary dysplasia (BPD). According to the radiographic findings the changes are categorized into four progressive stages. Stage 1 describes a radiographic feature with a pattern of fine, faint granularity as it is characteristic for the hyaline-membrane-syndrome. Stages 2 to 4 represent diffuse interstitial emphysema, a bubbly appearance of the lung, atelectasis and a progressive fibrosis. Electronmicroscopic investigations of bronchial imprints could demonstrate a rarefication of the cilia and a ciliary damage which took the form of compound cilia. In addition, a marked increase of goblet cells in the bronchial mucosa as well as a metaplasia of the epithelial cells was present. These findings may be a prerequisite for chronic infections, and perpetuate a cycle which may result in chronic obstructive airway disease. The significance of bronchial and bronchiolar injury in children with BPD is said to be due to IPPV, high inspiratory oxygen concentrations, high fluid intake, vitamin E deficiency or an increased intrapulmonary pressure secondary to a patent ductus arteriosus. When pulmonary mechanics were measured in a baby-body-plethysmograph a high pulmonary resistance and a low dynamic compliance occurred at the first investigation after IPPV or oxygen administration. On re-examination there was a strong tendency to normalisation of x-ray findings and pulmonary mechanics, depending upon the time which elapsed between ventilation and re-examination. Current therapy has to be symptomatic and may include secretolytics, glucocorticoids and bronchodilators. The preventive interventions have to take into consideration ventilation techniques, restrictions in O2 and fluid intake.

Bronchi↗