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Biomedical subjects

M Bamshad

Publications and source records attributed to M Bamshad.

42 records · Page 3Linked to original sources

Cohabitation alters vasopressin innervation and paternal behavior in prairie voles (Microtus ochrogaster).

The density of vasopressin-immunoreactive (AVP-ir) fibers in the lateral septum and lateral habenular nucleus is lower in prairie vole fathers--which display paternal behavior under natural conditions-than in sexually naive males. To see if these changes occur before or after the birth of pups, and whether they are related to changes in paternal behavior, we tested paternal responsiveness and measured AVP-ir fiber density in the lateral septum, lateral habenular nucleus, medial preoptic area, and paraventricular nucleus of the thalamus of sexually naive males and females (0P) and breeding pairs that were sacrificed shortly after mating (3P); during early (13P); or late gestation (21P); or after the birth of pups (6PP). Paternal responsiveness was increased in 3P males and reached a plateau in 13P males. AVP-ir fiber density did not change in the medial preoptic area and the paraventricular nucleus of the thalamus. The fiber density in the lateral septum and lateral habenular nucleus was affected differently in males and females. Among males, 3P animals had the lowest fiber density, while 13P and 6PP animals had an intermediate, and 0P and 21P animals the highest fiber density, whereas among females, no differences in fiber density were found. A second experiment showed that the decrease in fiber density in 3P males could be induced by cohabitation with an unfamiliar female but not by an unfamiliar male nor by relocation to a novel cage. The changes in AVP-ir fiber density shortly after mating suggest that these fibers may be involved in paternal responsiveness as well as in various other social behaviors that change after mating.

Amygdala↗

A gene for distal arthrogryposis type I maps to the pericentromeric region of chromosome 9.

Club foot is one of the most common human congenital malformations. Distal arthrogryposis type I (DA-1) is a frequent cause of dominantly inherited club foot. Performing a genomewide search using short tandem repeat (STR) polymorphisms, we have mapped a DA-1 gene to the pericentromeric region of chromosome 9 in a large kindred. Linkage analysis has generated a positive lod score of 5.90 at theta = 0, with the marker GS-4. Multiple recombinants bracketing the region have been identified. Analysis of an additional family demonstrated no linkage to the same locus, indicating likely locus heterogeneity. Of the autosomal congenital contracture disorders causing positional foot deformities, this is the first to be mapped.

Arthrogryposis↗

Sex and species differences in the vasopressin innervation of sexually naive and parental prairie voles, Microtus ochrogaster and meadow voles, Microtus pennsylvanicus.

To study whether central systems that are implicated in functions associated with reproduction show different changes in males and females that become parental, the central vasopressin (AVP) innervation was compared in two species of voles: prairie voles, in which males and females provide parental care, and meadow voles, in which only females provide parental care. For both species, the densities of AVP-immunoreactive (AVP-ir) fibers in the lateral septum, lateral habenular nucleus, medial preoptic area and paraventricular nucleus of the thalamus were compared in males and females that were sexually inexperienced or had become parents 6 days before sacrifice. The lateral septum and lateral habenular nucleus presumably receive their projections from the bed nucleus of the stria terminalis and medial amygdaloid nucleus, while the other two areas presumably receive their projections from the suprachiasmatic nucleus. Differences between sexually naive and parental animals were found only in the presumed projections of the bed nucleus of the stria terminalis and medial amygdaloid nucleus. In both species, AVP-ir fiber densities in the lateral habenular nucleus and the lateral septum were much greater in males than in females regardless of parental state. In prairie voles, AVP-ir fiber density in the lateral septum and lateral habenular nucleus was reduced in parental males, while no differences were found in females. In parental meadow voles, the AVP-ir fiber density in the lateral septum did not show changes, while the fiber density in the lateral habenular nucleus was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Acute upper airway obstruction in rheumatoid arthritis of the cricoarytenoid joints.

We have reported two cases of acute, life-threatening upper airway obstruction due to previously unrecognized rheumatoid arthritis of the cricoarytenoid joints with severe acute and chronic deformities of the larynx. Attempted endotracheal intubation with the rigid laryngoscope failed in each case, resulting in the need for emergency tracheostomy. We recommend the use of the fiberoptic bronchoscope for elective or emergency endotracheal intubations in patients with severe rheumatoid arthritis involving the cervical spine and the larynx.

Acute Disease↗

Identical mutations in NOG can cause either tarsal/carpal coalition syndrome or proximal symphalangism.

PURPOSE: To identify the gene causing tarsal/carpal coalition syndrome (TCC). METHODS: Individuals from three kindreds with TCC and normal hearing were used to map TCC and screen for mutations in Noggin (NOG). RESULTS: Three different missense mutations in NOG were found. Two of these mutations are identical to mutations previously reported to cause proximal symphalangism (SYM1). CONCLUSIONS: TCC is allelic to SYM1, and at least two different mutations in NOG can result in either TCC or SYM1 in different families. This finding suggests that phenotypic differences between these conditions are caused by epistatic modifiers of NOG.

Abnormalities, Multiple↗