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Biomedical subjects

S Baumgartner

Publications and source records attributed to S Baumgartner.

54 records · Page 3Linked to original sources

Structure of two genes at the gooseberry locus related to the paired gene and their spatial expression during Drosophila embryogenesis.

The gooseberry (gsb) locus contains two closely linked genes, BSH9 and BSH4, which are structurally related to each other and to the paired (prd) gene. Sequence analysis of genomic DNA and cDNA shows that BSH9 and BSH4 can encode proteins of 427 and 452 amino acids, respectively. The structural homology between these two putative proteins and the prd protein consists essentially of two domains forming most of the amino-terminal halves of the proteins: the prd domain of 128 amino acids and a prd-type homeo domain of 60 amino acids, which is extended by 18 amino acids at its amino-terminal end. The temporal profiles of BSH9 and BSH4 transcripts, as characterized by Northern analysis, show a peak shortly after the peak of prd transcripts. The spatial distributions of BSH9 and BSH4 transcripts have been analyzed by in situ hybridization to whole-mount and sectioned embryos. BSH9 transcripts appear in the posterior ventrolateral part of each primordial segment throughout the embryo, including head and tail segments. Transcripts are initially restricted to the ectoderm, in which they arise as two spatially shifted and temporally delayed waves exhibiting double-segment periodicity and anteroposterior polarity. During germ-band extension, BSH9 is induced in the mesoderm in register with the ectoderm and neurectoderm and in the tail segments A9-A11. In contrast, BSH4 transcripts appear with a single-segment repeat, first, in the neurectoderm during germ-band extension and, later, in single neurons during neuronal differentiation. BSH9, BSH4, and prd are activated in cells that are in register along the anteroposterior axis of the embryo in the posterior parts of primordial segments comprising the posterior compartments of engrailed expression.

Age Factors↗

Conservation of a large protein domain in the segmentation gene paired and in functionally related genes of Drosophila.

Extending our search for homologous domains of the Drosophila paired gene, two closely linked genes at the gooseberry locus have been isolated. Both genes are expressed with a single segment periodicity but with different spatial and temporal expression patterns. While the transcripts of one gene appear earlier and are equally distributed between ectoderm and mesoderm, those of the second gene accumulate preferentially in neuroblasts. The similarity of these expression patterns to the 14-band pattern of the paired gene suggests a functional relationship. Such a functional link may be reflected in the two structurally homologous domains shared with the paired gene: a new type of homeo box extended by 18 amino acids at the 5' end, and a new domain, the paired box, consisting of a sequence of 128-135 amino acids. Thus, together with the PRD repeat, the paired gene contains at least three different domains, each defining a gene set thought to be important for development.

Animals↗

Structure of the segmentation gene paired and the Drosophila PRD gene set as part of a gene network.

The sequence of paired, a pair-rule gene required for segmentation in Drosophila, is presented. A search for genes with domains homologous to the paired gene was initiated and three homologues from a set of 12 were characterized with respect to temporal or spatial expression and sequence homologies. All four are transcribed in early development, one in the oocyte and during cleavage stages in the form of a gradient. In addition to the prd-specific his-pro repeat, some of the 12 genes contain M-repeats and two new types of homeo boxes not detectable by hybridization with the two known classes of homeo boxes. The observed linking of gene sets through combinations of homologies coding for protein domains is consistent with a general network concept of gene action.

Amino Acid Sequence↗

Cloning of the extra sex combs gene of Drosophila and its identification by P-element-mediated gene transfer.

A large region containing the extra sex combs (esc) gene of Drosophila has been cloned by microdissection from polytene chromosomes and chromosomal walking. Within this DNA, the segment comprising the esc gene has been narrowed down in several steps. First, a deletion of the esc gene, Df(2L)esc, defined a region of 380 kb. Then, a duplication carrying the esc gene, Dp(2;2)GYL, and a deletion not eliminating esc, Df(2L)prd, further reduced this region to 160 kb. Finally, because esc transcripts are expected to be present in follicles but absent in adult males, mapping of follicle and adult male transcripts limited the esc region to 10 kb. Rigorous proof that this DNA contained the esc gene was obtained by P-element-mediated transformation. We conclude that the 12 kb of DNA used for transformation include the esc gene as well as all flanking sequences required for its proper regulation in the female germ line.

Journal Article↗

Ocular effects of oral lithium in humans.

Thirteen healthy adult subjects, 34.2 +/- 7.4 years of age received oral lithium carbonate, 900 or 1200 mg daily for 10 days. Refraction, visual acuity, visual fields, corneal sensation, basal tear secretion, ocular motility, convergence amplitude, near point of convergence, Hertel exophthalmometry, pupillary reflexes, intraocular pressure, voluntary and pilocarpine-induced accommodation, and biomicroscopy and ophthalmoscopy of the anterior and posterior ocular segments were determined 4 days prior to starting lithium, 10 days after commencing lithium, and 14 days after discontinuing lithium. Some subjective visual or ocular complaints were reported, but no clinically or statistically significant change occurred in any parameter studied. There were slight, non-significant tendencies toward constriction of the measured visual field, reduction of voluntary and pilocarpine-induced accommodation, and reduction of near convergence amplitude while taking lithium; the former two were reversed when lithium was discontinued, the latter was not.

Accommodation, Ocular↗

Family admission policy in a child psychiatric unit.

The literature on residential admissions of whole families to psychiatric facilities is reviewed. Over the past decade, several child and family psychiatric centres have become the focus of innovative family admission programs. When a child or family presents with serious psychiatric problems, the availability of such programs dramatically increases the effective assessment and treatment options available. The benefits of a whole family admission policy are outlined and illustrated by a case example. In some cases, a brief family admission circumvents the need for a lengthy admission of the child alone. Disadvantages and contraindications are described. The adoption of a set of criteria and a specific policy for family admissions in a child psychiatric residential unit has challenged its organisational structure. The conceptual framework applied to requests for admission has broadened and been complemented by creative program development within the centre for children and families.

Adolescent↗

Refractive keratoplasty. Keratophakia in a nonhuman primate.

We performed 11 keratophakia procedures in a baboon (Papio cynocephalus) model using the same instruments and techniques that are presently clinically employed. We requested 10 diopters of correction in nine cases and 14 D in two cases. We were able to achieve a mean (+/- SD) keratometric steepening correction of 5.8 +/- 1.5 D using fresh and 9.3 +/- 5.0 D using prefrozen donor corneas. The overall change was 8.0 +/- 4.3 D. Morphologic results and corneal clarity were consistent with the excellent clinical results. The keratophakia lenticles were sparsely repopulated with keratocytes up to six months following surgery, but at 12 months, partial keratocyte repopulation of one lenticle did occur. We recommend that the baboon model be used for evaluation of all lamellar refractive surgical procedures.

Animals↗

[Physiological effects of needle guns on the hand-arm system].

Physiological effects and sensations of four air actuated needle-pistols of different constructions on the hand-arm-system were explored (n = 4). As no reliable standards of injurious effects are known, only comparative conclusions can be drawn. All parameters showed a significant diminution of vibration effects when using a machine constructed with a shock absorber.

Adult↗

Chronic granulomatous disease: effect of sulfamethoxazole/trimethoprim on neutrophil microbicidal function.

Normal and chronic granulomatous disease (CGD) neutrophils accumulated sulfamethoxazole (SMX) 3-fold and trimethoprim (TMP) 14-fold, possibly through a non-ionic diffusion and pH-partition mechanism. CGD neutrophils incubated with SMX/TMP after phagocytosis of S. aureus killed the bacteria. These findings explain the clinically observed beneficial effect of SMX/TMP in the treatment of infections in CGD and in other conditions characterized by impaired phagocyte microbicidal capacity.

Drug Therapy, Combination↗

Copper deficiency in the laying hen.

Copper deficiency in the laying hen resulted in anemia and the production of eggs which were abnormal in size and shape. Many of the eggs had shells which were wrinkled and rough in texture. There was also an increase in the number of shell-less eggs. Examination of malformed egg shells using the scanning electron microscope revealed ultrastructural changes in the mammillary layer of the shell. The effect of copper deficiency on shell formation was attributed to the shell membranes which were altered in color, appearance, and physical consistency. Amino acid analysis of the membranes indicated that the membranes from copper deficient hens were characterized by an increase in lysine content. This suggests that copper is necessary for the formation of lysine derived cross-links in a manner similar to that which occurs in connective tissue. The exact nature of these cross-links is unknown at this time.

Amino Acids↗

Dermatophytomycoses in children in rural Kenya: the impact of primary health care.

In a survey of 5780 children from 13 schools in rural Kisumu District (western Kenya) in 1993, a prevalence rate of dermatophytomycoses of 10.1% was found. Three-quarters of the affected children suffered from tinea capitis (prevalence rate 7.8%), caused by Microsporum audouinii var. langeronii, Trichophyton violaceum and Microsporum canis. In 1994, a dermatology programme within the primary health care system was started. Twelve community health workers (CHWs), trained in diagnosis and treatment of the most common skin diseases, carried out regular school visits once a week. All dermatophytomycoses, dry forms of tinea capitis included, were treated locally with Whitfield's ointment. In 1995 the prevalence rate of fungal skin infections in the same schools was found to be 9.3%; the difference to 1993 was not significant. Only tinea capitis, with a prevalence rate of 5.8%, showed a significant reduction (P < 0.05). Altogether, a distinctive improvement regarding the extent and the severity of dermatophytomycoses could be noticed. In the cultures from tinea capitis, Microsporum canis was not found to be present. Trained community health workers are capable of the diagnosis and treatment of fungal skin infections of children in rural areas, which leads to a reduction in the prevalence of tinea capitis.

Antifungal Agents↗

The diagnosis and management of the superior rectus suspension syndrome.

The diagnosis and management of patients having had superior rectus suspension procedures for the correction of blepharoptosis can be quite difficult. Patients who have had these procedures frequently present with a syndrome which included 1) history of an unknown type of ptosis surgery performed at least ten years ago, 2) good eyelid excursion, 3) minimal lid lag associated with marked lagophthalmos, 4) hypotropia, and 5) corneal scarring. One must evert the upper eyelid to demonstrate the pathognomonic adhesion between tarsus and the superior rectus muscle. The correct management of this condition is virtually impossible until the diagnosis is made. To correct the corneal and motility problems that result from superior rectus suspension procedures, the adhesion between the superior rectus muscle and the upper eyelid must be released. It is very easy to overlook this syndrome if one is unaware of its presentation. We present five patients who illustrate the superior rectus suspension syndrome.

Blepharoptosis↗

Racial variation in lung cancer.

Lung cancer claimed about 153,000 lives in 1994 in the United States. Despite research overall lung cancer survival has still not improved during the last 20 years, with 5-year relative survival remaining about 13%. In addition several epidemiologic and molecular studies showed a difference in the incidence of lung cancer in the three major races. The aim of our study was to investigate the variations of race in lung cancer patients, in order to identify potential risk factors linked to the different racial status. In this light we compared a 10 years lung cancer data of black population from Howard University Hospital, Washington D.C., U.S.A. and a 20 years data of white population from the Vienna University Hospital, Austria. Our results did not show any significant difference in mean age or tumor localization in both groups, but highlighted a remarkable difference in the incidence of the lung cancer histological types also according to the sex. In this respect it could be more successful to consider carcinogenesis like a protracted process of gene function deregulation in response to cell injury from exposure to genotoxic substances with individual specificity.

Adult↗