Serum- and bradykinin-induced calcium transients in familial Alzheimer's fibroblasts

The calcium-sensitive photoprotein, aequorin, was used to examine serum- and bradykinin-induced transient increases in free cytosolic calcium ions in skin fibroblasts from 10 individuals with early onset familial AD (FAD), including four who were biopsied before their clinical symptoms would allow a diagnosis of AD, 2 individuals with late onset FAD, 8 at-risk but nonsymptomatic individuals, and 13 controls. The data show that (a) among controls, the peaks of the calcium transients increase in height as a function of donor age; (b) transients induced by 10% serum, 10 nM bradykinin (BK) or 100 nM BK were generally lower in FAD fibroblasts, including those from donors in the early stages of the disease, than in age-matched control cells; (c) such transients are reduced in cells from a proportion of the nonsymptomatic, at-risk individuals. Thus, serum- and BK-induced calcium transients are reduced in fibroblasts from both early and more advanced stage FAD donors and perhaps even from donors who are presymptomatic carriers of the defective gene. The data also suggest that changes in calcium transients in FAD fibroblasts neither mimic nor exaggerate the effects of normal aging.     

Mutations in the COL1A2 gene of type I collagen that result in nonlethal forms of osteogenesis imperfecta

Although virtually all mutations that result in osteogenesis imperfecta (OI) affect the genes that encode the chains of type I procollagen, the effects of mutations in the COL1A2 gene have received less attention than those in the COL1A1 gene. We have characterized mutations in 4 families that give rise to different OI phenotypes. In three families substitutions of glycine residues by cysteine in the triple helical domain (a single example at position 259 and 2 families in which substitution of glycine at 646 by cysteine) have been identified, and in the fourth a G for A transition at position +4 in intron 33 led to use of an alternative splice site and inclusion of 6 amino acids (val-gly-arg-ile-leu-phe) between residues 585 and 586 of the normal triple helix. The relation between position of substitution of glycine by cysteine in the COL1A2 gene does not follow the pattern developed in the COL1A1 gene. To determine how COL1A2 mutations produce OI phenotypes, we have produced a full-length mouse cDNA into which we plan to place mutations and examine their effects in stably transfected osteogenic cells and in transgenic animals.     

Spontaneous fistula formation as a complication of relaxing incisions with suture placement for postkeratoplasty high astigmatism

A 39-year-old man had a corneal relaxing incision with corneal compression suture placement to correct more than 10 diopters of corneal astigmatism. A permanent fistula formed from the compression suture, resulting in a localized corneal pocket of aqueous that broke through the surface. The aqueous drained into the tear film, requiring major surgical repair.     

Results of renal transplantation in boys treated for posterior urethral valves

The results of renal transplantation in boys treated for posterior urethral valves were evaluated and compared with a matched control group. Patient and graft survival was equal in both groups, although serum creatinine levels were slightly higher in the posterior urethral valves group. Postoperative complications, such as urinary tract infections, occurred more frequently in the posterior urethral valves group. Urodynamic evaluation was performed before transplantation in 11 of 20 patients. Adequate treatment of bladder dysfunction, such as poor compliance and/or hyperreflexia, is essential in diminishing the risks of secondary graft damage due to severe bladder dysfunction.     

Virulence and viability of Yersinia pestis 25 years after lyophilization

When equal volumes of 6% lactose and a broth culture of Yersinia pestis were mixed before freezing, approximately 50% of the cells survived lyophilization and reconstitution on the following day. Concomitantly, the number of viable cells per 50% lethal dose increased from about 16 to 125 organisms. On subsequent storage of the lyophilized cells under vacuum in glass ampoules at 4 degrees C for 25 years, more than 25% of the cells remained viable. When stored cultures were assayed immediately after reconstitution, virulence for mice was significantly reduced (as many as 4,000 cells/50% lethal dose), but the virulence was fully restored when reconstituted cultures were held for 24 h at room temperature, or when a subculture was prepared in fresh medium.