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Biomedical subjects

B Grossmann

Publications and source records attributed to B Grossmann.

16 recordsLinked to original sources
PubMed2006

Segmental duplication associated with evolutionary instability of human chromosome 3p25.1.

Fluorescence in situ hybridization (FISH) of human bacterial artificial chromosome (BAC) clones to orangutan metaphase spreads localized a breakpoint between human chromosome 3p25.1 and orangutan chromosome 2 to a <30-kb interval. The inversion occurred in a relatively gene-rich region with seven genes within 500 kb. The underlying breakpoint is closely juxtaposed to validated genes, however no functional gene has been disrupted by the evolutionary rearrangement. An approximately 21-kb DNA segment at the 3p25.1 breakpoint region has been duplicated intrachromosomally and interchromosomally to multiple regions in the orangutan and human genomes, providing additional evidence for the role of segmental duplications in hominoid chromosome evolution.

Animals↗
PubMed2005

Disruption of TCBA1 associated with a de novo t(1;6)(q32.2;q22.3) presenting in a child with developmental delay and recurrent infections.

A boy with developmental delay, particularly of speech, a distinct face, antineutrophil cytoplasmic antibodies, and recurrent infections was found to have an apparently balanced de novo t(1;6)(q32.3;q22.3) translocation. Fluorescent in situ hybridisation with BAC/PAC clones and long range polymerase chain reaction products assessed in the human genome sequence localised the chromosome 1 breakpoint to a 9.8 kb segment within a hypothetical gene, LOC388735, and the chromosome 6 breakpoint to a 12.8 kb segment in intron 4 of the T-cell lymphoma breakpoint-associated target 1 (TCBA1) gene. Disruption and/or formation of TCBA1 fusion genes in T cell lymphoma and leukaemia cell lines suggests a role for this gene in tumorigenesis. The isolated mouse Tcba1 gene shows 91% amino acid sequence similarity with human TCBA1. It is expressed in fetal and adult brain and with lower levels in liver and testis. The human gene has been reported to be expressed exclusively in brain and thymus. Reduced TCBA1 expression in brain and thymus may explain at least some of the symptoms in this patient. It is concluded that germline alterations of the TCBA1 gene are associated with developmental delay and typical physical features.

Amino Acid Sequence↗
PubMed2005

Genomic structure and paralogous regions of the inversion breakpoint occurring between human chromosome 3p12.3 and orangutan chromosome 2.

Intrachromosomal duplications play a significant role in human genome pathology and evolution. To better understand the molecular basis of evolutionary chromosome rearrangements, we performed molecular cytogenetic and sequence analyses of the breakpoint region that distinguishes human chromosome 3p12.3 and orangutan chromosome 2. FISH with region-specific BAC clones demonstrated that the breakpoint-flanking sequences are duplicated intrachromosomally on orangutan 2 and human 3q21 as well as at many pericentromeric and subtelomeric sites throughout the genomes. Breakage and rearrangement of the human 3p12.3-homologous region in the orangutan lineage were associated with a partial loss of duplicated sequences in the breakpoint region. Consistent with our FISH mapping results, computational analysis of the human chromosome 3 genomic sequence revealed three 3p12.3-paralogous sequence blocks on human chromosome 3q21 and smaller blocks on the short arm end 3p26-->p25. This is consistent with the view that sequences from an ancestral site at 3q21 were duplicated at 3p12.3 in a common ancestor of orangutan and humans. Our results show that evolutionary chromosome rearrangements are associated with microduplications and microdeletions, contributing to the DNA differences between closely related species.

Animals↗
PubMed2000

Conservation of the deleted-in-azoospermia-like-1 (DAZL1) gene structure in old world monkeys points to a homologous function of DAZL1 in this primate class.

We isolated the complete deleted-in-azoospermia-like-1 (DAZL1) gene of the old world monkey Macaca fascicularis (tentatively designated as MafaDAZL1) and compared its sequence structure to that of the other DAZL1 genes isolated so far. In addition to the homologous RNA recognition motif (RRM domain), we only identified a high conservation of the Mafa-DAZL1 coding region to the mammalian DAZL1 genes (i.e. mouse: Dazl1; and human: DAZL1) and to that of Xenopus (xdazl). Only in the primates, Macaca fascicularis and human, sequences and lengths of the 5' and 3' untranslated DAZL1 gene structures (UTRs) displayed a similar conservation as their coding regions (i.e. 91-94%). Both belong to the primate class of old world monkeys evolutionarily separated 36-55 million years ago (1). The strong conservation of the complete DAZL1 gene structure in both primate species suggests a similar control and maturation pathway of DAZL1 transcripts in the germ line of old world monkeys and also indicates a homologous function of the DAZL1 RNA-binding protein in this primate class.

3' Untranslated Regions↗
PubMed1999

[Tubero-pustular demodicosis].

A 38-year-old female patient suddenly developed an unusual tuberous, pustular tumor on her chin. On the basis of clinical pattern, histological and microbiological investigations the diagnosis of demodicosis was established. Histological investigation revealed follicular cysts and a chronic granulomatous perifolliculitis with many of Demodex folliculorum. A large number of mites could be also identified by microscopy of smears from pustules. No cellular or humoral immunological defects, tumours nor systemic disorders were found. After oral therapy with steroids and metronidazole, the lesions improved rapidly.

Adult↗
PubMed1993

Hawaii's near-universal health insurance--lessons learned.

To date, Hawaii is the only state to have implemented near-universal health insurance. The cornerstone of this program is the country's only requirement that employers provide health insurance for all employees who work at least 20 hours per week. Combined with low unemployment, voluntary modified community rating by health insurers, and expanded Medicaid and Medicare, this employer mandate has been part of a patchwork mechanism that insures upwards to 95 percent of the state's population. Indeed, by adding a state-sponsored gap group-insurance program, Hawaii may now insure in excess of 95 percent of its population. The program has generated good health outcomes, good consumer satisfaction, and relatively modest overall health care expenditures. But for all that near-universal insurance provides, there is still a great need for community-based preventive and primary care programs with outreach and family support services. In addition, traditionally underserved populations continue to be at increased risk. Both funding reform and continued infrastructure development must occur to achieve universal access to care.

Cost-Benefit Analysis↗
PubMed1991

A stochastic branching model with formation of subunits applied to the growth of intestinal crypts.

The intestinal epithelium is one of the most rapidly regenerating tissues in mammals. Cell production takes place in the intestinal crypts which contain about 250 cells. Only a minority of 1-60 proliferating cells are able to maintain a crypt over a long period of time. However, so far attempts to identify these stem cells were unsuccessful. Therefore, little is known about their cellular growth and selfmaintenance properties. On the other hand, the crypts appear to exhibit a life cycle which starts by fission of existing crypts and ends by fission or extinction. Data on these processes have recently become available. Here, we demonstrate how these data on the life cycle of the macroscopic crypt structure can be used to derive a quantitative model of the microscopic process of stem cell growth. The model assumptions are: (1) stem cells undergo a time independent supracritical Markovian branching process (Galton-Watson process); (2) a crypt divides if the number of stem cells exceeds a given threshold and the stem cells are distributed to both daughter crypts according to binomial statistics; (3) the size of the crypt is proportional to the stem cell number. This model combining two different stochastic branching processes describes a new class of processes whose stationary stability and asymptotic behavior are examined. This model should be applicable to various growth processes with formation of subunits (e.g. population growth with formation of colonies in biology, ecology and sociology). Comparison with crypt data shows that intestinal stem cells have a probability of over 0.8 of dividing asymmetrically and that the threshold number should be 8 or larger.

Animals↗
PubMed1989

Molecular probes for the detection of Kluyveromyces marxianus chromosomal DNA in electrophoretic karyotypes of intergeneric protoplast fusion products.

Random genomic DNA fragments from Kluyveromyces marxianus were cloned in order to identify chromosomal bands in pulsed field electrophoresis patterns of intergneric hybrid strains which were obtained by protoplast fusion. Molecular hybridization data indicated that the K. marxianus parental strain might be triploid, and it showed strong chromosome length polymorphism. We analyzed the karyotype of two Saccharomyces cerevisiae/K. marxianus hybrid strains (St. 1.St.46) with our DNA probes and with a Ty1 specific probe. We found indications for recombinational events which lead to the formation of hybrid chromosomal DNA molecules.

Blotting, Southern↗