Identification of loci determining susceptibility to the lethal effects of amyloid precursor protein transgene overexpression

Phenotypes produced by expression of human amyloid precursor protein (APP) transgenes vary depending on the genetic background of the mouse. FVB/N mice overexpressing human APP695 develop a central nervous system disorder and die prematurely, precluding development of Abeta peptide amyloid plaques. 129S6 mice are resistant to the lethal effects of APP overexpression, allowing sufficient levels of Abeta expression for the development of amyloid plaques and age-dependent memory deficits. To identify the genes that determine susceptibility or resistance to APP we analyzed crosses involving FVB/NCr and 129S6.Tg2576 mice that overexpress 'Swedish' mutant (K670N, M671L) APP695. APP transgene-positive FVB129S6F1 (F1) mice are resistant to the lethal effects of APP overexpression, so FVBxF1 backcross and F2 intercross offspring were produced. Analysis of age of death as a quantitative trait revealed significant linkage to loci on proximal chromosome 14 and on chromosome 9; 129S6 alleles protect against the lethal effects of APP. Within the chromosome 14 interval are segments homologous to regions on human chromosome 10 that have been linked to late onset Alzheimer's disease or to levels of Abeta peptide in plasma. However, analysis of plasma Abeta peptide concentrations at 6 weeks in backcross offspring produced no significant linkage. Similarly, elevation of human Abeta peptide concentrations by expression of mutant presenilin transgenes did not increase the proportion of mice dying prematurely, suggesting that early death reflects effects of APP or fragments other than Abeta.     

Recurrent diffuse lipomatosis of the neck--a case report

Diffuse lipomatosis is a rare disorder of adipose tissue occurring in young people . It has a predilection for trunk and proximal extremities where it presents as poorly circumscribed overgrowth of fatty tissue. Definite diagnosis is established by histological examination of tumor. Though it attains extensive size and has a high tendency to recur, the clinical course is benign.     

Patterns of coverage of psychiatric emergencies

A massive change in the detection of psychiatric cases in the emergency room was recorded when pattern of coverage was changed from "on-call" basis to "continuous physical presence" of psychiatry residents in the emergency room.     

Prostaglandin E1-induced Catalepsy in the Rat: Role of Putative Neutrotransmitters

Prostaglandin E₁ (PGE₁) produced dose-related catalepsy in rats when administered intracerebroventricularly. PGE₁ induced catalepsy was significantly inhibited after pretreatment with pharmacological agents known to attenuate central serotonergic and cholinergic activity. It was also inhibited by PGF₂ and naloxone. On the contrary, treatments enhancing central dopaminergic activity also reduced the cataleptic effect of PGE₁. The results suggest that PGE₁ induces catalepsy in rats by modulating activity of central neurotransmitters.