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Biomedical subjects

B Becker

Publications and source records attributed to B Becker.

At least 109 records · Page 6Linked to original sources
PubMed1991

[Osteosynthesis of the clavicle. Indications, surgical technique, results].

The osteosynthesis of the clavicle should be the exception and should only be indicated in the case of complicated fractures. The high rate of pseudoarthrosis given in medical literature, is due to errors in indication, selection of implants and in surgical techniques. Procedures like intramedullar wiring, axial screwing and single cerclage-wire suture are unsuited for osteosynthesis of the clavicle. After osteosynthesis of the clavicle we have found exceptional positive results, with respect to functional, radiological and after subjective evaluation, at a low rate of complication without any consequences occurring in the years to come. These results show, that mainly good or even excellent success can be achieved, at a limited indication, combined with careful surgery and a standardized surgery procedure of osteosynthesis of the clavicle.

Adolescent↗
PubMed1990

Neurologic, computed cranial tomographic, and magnetic resonance imaging abnormalities in patients with small-cell lung cancer: further follow-up of 6- to 13-year survivors.

To determine the subsequent evolution of neurologic, neuropsychologic, and intracranial anatomic findings in long-term survivors of small-cell cancer, we repeated an evaluation done 4 years previously in patients 6 to 13 years after treatment. Fifteen patients were reevaluated with a history and physical examination, mental status examination, neuropsychologic testing, computed cranial tomographic (CCT) scans, and magnetic resonance imaging (MRI). All but one was ambulatory and none were institutionalized. Thirteen of 15 had neurologic complaints, 10 of 15 had an abnormal neurologic examination, seven of 14 had an abnormal mental status examination, 12 of 14 had abnormal neuropsychologic testing, 12 of 15 had abnormal CCT scans, and seven of 15 had white-matter abnormalities on MRI scans. No dramatic decline in performance status, functional status, neurologic symptoms, or neurologic examination occurred in these patients with 4 years of additional follow-up. More patients showed a decline in mental status examinations and neuropsychologic testing than demonstrated improvement. Anatomic studies showed no dramatic changes in the CCT scans and MRI confirmed these findings. From these data we conclude that there is a slow decline in neuropsychologic function in some of the patients surviving more than 6 years from a diagnosis of small-cell lung cancer. The anatomic abnormalities documented by CCT scans and MRI are more frequent in patients with abnormal neuropsychologic function.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Topical 8-bromo-cyclic GMP lowers intraocular pressure in rabbits.

The topical application of 8-bromo-3'-5'-cyclic guanosine monophosphate (8BrcGMP) produces significant decreases in intraocular pressure (IOP) in rabbit eyes. Maximum effects are obtained with a 4% concentration, and IOP is reduced significantly (P less than 0.001) between 30 and 240 min after administration of the agent. The decrease in IOP occurs without significant change in tonographic outflow facility. A significant further decrease in IOP can be induced by topical 8BrcGMP in rabbits whose IOP has been lowered by the systemic administration of the carbonic anhydrase inhibitor acetazolamide.

Acetazolamide↗
PubMed1990

[A new method for determination of nicotinic acid in plasma].

A new and sensitive method for the detection of nicotinic acid in plasma is described. Human or rat plasma-samples from pharmacological or pharmacokinetic studies are lyophilized and extracted with methanol. After removal of the solvent the residue is converted with N-Methyl-N-trimethylsilyltrifluoracetamide to the trimethylsilylester of nicotinic acid, separated by vpc and detected with a mass selective detector via the fragment 180 amu. 6-Methyl-nicotinic acid is used as internal standard (fragment 194 amu). With this method a detection limit of 100 ng/ml plasma is reached.

Animals↗
PubMed1989

Identification of 3-deoxy-manno-2-octulosonic acid, 3-deoxy-5-O-methyl-manno-2-octulosonic acid and 3-deoxy-lyxo-2-heptulosaric acid in the cell wall (theca) of the green alga Tetraselmis striata Butcher (Prasinophyceae).

The main constituent of the cell wall complex carbohydrate of the scaly green alga Tetraselmis striata Butcher is shown to be 3-deoxy-manno-2-octulosonic acid (42%). In addition two other 2-keto-sugar acids are present, namely, 3-deoxy-5-O-methyl-manno-2-octulosonic acid (7%), the first methylated derivative of 3-deoxy-manno-2-octulosonic acid found in nature, and 3-deoxy-lyxo-2-heptulosaric acid (11%). The characterization of the three 2-keto-sugar acids has been carried out on the corresponding methyl ester methyl glycosides using GLC-MS and 500-MHz 1H-NMR spectroscopy, and on the corresponding reduced alditol acetates using GLC-MS. Other monosaccharides occurring in the cell wall are D-galacturonic acid (14%), D-galactose (4%), D-gulose (2%), D-glucose (1%) and L-arabinose (1%).

Cell Wall↗
PubMed1989

Topical timolol administration reduces the incidence of glaucomatous damage in ocular hypertensive individuals. A randomized, double-masked, long-term clinical trial.

We conducted a randomized, double-masked, long-term clinical trial to determine whether topical timolol therapy was effective in delaying or preventing the onset of glaucomatous damage in moderate-risk ocular hypertensive subjects. In 62 patients, one eye was chosen randomly to receive timolol therapy twice daily while the fellow eye received placebo. During the course of the study, the mean +/- SD difference in intraocular pressure between the timolol-treated and the placebo-treated eyes was 2.3 +/- 2.6 mm Hg. Reproducible visual field loss developed in 4 timolol-treated eyes and 10 placebo-treated eyes. Progressive optic disc cupping was noted in 4 timolol-treated and 8 placebo-treated eyes. Using a computerized image analysis system, the mean +/- SD increase in optic disc pallor during the course of the study was 0.86% +/- 2.4% in the timolol-treated eyes as opposed to 1.80% +/- 3.6% in the placebo-treated eyes. This study provides evidence that lowering intraocular pressure by medical treatment reduces the incidence of glaucomatous damage in ocular-hypertensive individuals.

Administration, Topical↗
PubMed1989

Atrial natriuretic peptides. Effects on intraocular pressure, cGMP, and aqueous flow.

We report a significant decrease in intraocular pressure after intravitreal injection of atrial natriuretic peptide (AP). There is also an increase in cGMP in iris-ciliary body preparations after exposure to physiologic concentrations of AP in vitro. We present evidence that after intravitreal AP administration there is a decrease in aqueous humor flow associated with the decrease in intraocular pressure. The changes in aqueous humor flow were estimated by automated fluorophotometry and aqueous humor ascorbate concentrations.

Animals↗
PubMed1989

Breakdown of the blood--aqueous barrier in the rabbit eye by infrared radiation.

Breakdown of the blood-aqueous barrier was produced by infrared radiation (IR) at a heat flux from 24 to 44 J/cm2 in pigmented, but not in albino rabbits. Blood-aqueous barrier breakdown was inhibited by indomethacin and ketamine/xylazine anesthesia mixtures, but not by [D-Trp2,D-Pro7,9]-substance P. The degree of blood-aqueous barrier breakdown could be controlled by IR flux. Two models for accurate determination of the heat flux are presented.

Albinism↗
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↗