Hydrogen sulfide production and fermentative gas production by Salmonella typhimurium require F0F1 ATP synthase activity

A previously isolated mutant of Salmonella typhimurium lacking hydrogen sulfide production from both thiosulfate and sulfite was shown to have a single mutation which also caused the loss of fermentative gas production and the ability to grow on nonfermentable substrates and which mapped in the vicinity of the atp chromosomal locus. The implication that F0F1 ATP synthase might be essential for H2S and fermentative gas production was explored. The phs plasmid conferring H2S production on wild-type Escherichia coli failed to confer this ability on seven of eight E. coli atp point mutants representing, collectively, the eight genes encoding the subunits of F0F1 ATP synthase. However, it did confer some thiosulfate reductase activity on all except the mutant with a lesion in the ATP synthase catalytic subunit. Localized mutagenesis of the Salmonella atp chromosomal region yielded 500 point mutants unable to reduce thiosulfate to H2S or to produce gas from glucose, but differing in the extents of their ability to grow on succinate, to perform proton translocation as measured in a fluorescence quenching assay, and to reduce sulfite to H2S. Biochemical assays showed that all mutants were completely devoid of both methyl viologen and formate-linked thiosulfate reductase and that N,N'-dicyclohexylcarbodiimide blocked thiosulfate reductase activity by the wild type, suggesting that thiosulfate reductase activity has an absolute requirement for F0F1 ATP synthase. Hydrogenase-linked formate dehydrogenase was also affected, but not as severely as thiosulfate reductase. These results imply that in addition to linking oxidation with phosphorylation, F0F1 ATP synthase plays a key role in the proton movement accompanying certain anaerobic reductions and oxidations.     

Pantophysin is a ubiquitously expressed synaptophysin homologue and defines constitutive transport vesicles

Certain properties of the highly specialized synaptic transmitter vesicles are shared by constitutively occurring vesicles. We and others have thus identified a cDNA in various nonneuroendocrine cell types of rat and human that is related to synaptophysin, one of the major synaptic vesicle membrane proteins, which we termed pantophysin. Here we characterize the gene structure, mRNA and protein expression, and intracellular distribution of pantophysin. Its mRNA is detected in murine cell types of nonneuroendocrine as well as of neuroendocrine origin. The intron/exon structure of the murine pantophysin gene is identical to that of synaptophysin except for the last intron that is absent in pantophysin. The encoded polypeptide of calculated mol wt 28,926 shares many sequence features with synaptophysin, most notably the four hydrophobic putative transmembrane domains, although the cytoplasmic end domains are completely different. Using antibodies against the unique carboxy terminus pantophysin can be detected by immunofluorescence microscopy in both exocrine and endocrine cells of human pancreas, and in cultured cells, colocalizing with constitutive secretory and endocytotic vesicle markers in nonneuroendocrine cells and with synaptophysin in cDNA-transfected epithelial cells. By immunoelectron microscopy, the majority of pantophysin reactivity is detected at vesicles with a diameter of < 100 nm that have a smooth surface and an electron-translucent interior. Using cell fractionation in combination with immunoisolation, these vesicles are enriched in a light fraction and shown to contain the cellular vSNARE cellubrevin and the ubiquitous SCAMPs in epithelial cells and synaptophysin in neuroendocrine or cDNA-transfected nonneuroendocrine cells and neuroendocrine tissues. Pantophysin is therefore a broadly distributed marker of small cytoplasmic transport vesicles independent of their content.     

Monitored outpatient management of mild gestational hypertension remote from term in teenage pregnancies

OBJECTIVE: Our purpose was to compare maternal and perinatal outcomes of teenage and adult pregnancies with mild gestational hypertension remote from term managed with an outpatient program. STUDY DESIGN: A matched cohort design was used. Maternal and perinatal outcomes of 60 teenage pregnancies with mild gestational hypertension remote from term were compared with 120 adult controls 20 to 42 years old. The groups were matched for race, gestational age, and proteinuria status at enrollment. All were monitored on an outpatient basis with four times daily automated blood pressure measurement and daily assessment of weight, proteinuria, and fetal movement. RESULTS: The mean gestational age at enrollment was 33.5 +/- 2.6 weeks for both groups (range 27 to 36 weeks). Only 60% of teenagers had a high school degree or equivalent compared with 76% of adults (p = 0.024). The teenagers were more likely than the adults to be of single marital status (75% vs 13%, p = 0.015). The mean gestational age at delivery (37.0 +/- 2.0 vs 37.0 +/- 2.2 weeks), mean pregnancy prolongation (23.5 +/- 19.0 vs 24.5 +/- 17.4 days), and mean birth weights (2915 +/- 669 vs 2879 +/- 678 gm) were not statistically different between the teenagers and adults (all p > 0.05). There were no stillbirths, neonatal deaths, or cases of eclampsia in either group. CONCLUSIONS: In spite of a study population characterized by limited education, single marital status, and young age at enrollment, monitored outpatient management of mild gestational hypertension remote from term in teenage pregnancies is associated with maternal and perinatal outcomes similar to those observed in adults.     

Bone mineral density in patients undergoing bone marrow transplantation for myeloid malignancies

Hitherto the biology of proteolysis in prokaryotes, particularly in archaea, is only poorly understood. We have used the tri-peptide vinyl sulfone inhibitor carboxybenzyl-leucyl-leucyl-leucine vinyl sulfone (Z-L3VS) to study the in vivo function of proteasomes in Thermoplasma acidophilum. Z-L3VS is a potent inhibitor of the Thermoplasma proteasome and is capable of modifying 75 to 80% of the proteasomal beta-subunits in cell cultures. Inhibition of proteasomes has only marginal effects under normal growth conditions. Under heat shock conditions, however, the effects of proteasome inhibition are much more severe, to the extent of complete cell growth arrest. These data suggest that other proteolytic systems may exist that can compensate for the loss of proteasome function in T. acidophilum.     

Structural consensus in ligand-protein docking identifies recognition peptide motifs that bind streptavidin

ALD affects a large segment of the population in the United States, both old and young, and men and women of all races and ethnicities. Many chronic diseases inevitably advance to a stage that results in significant respiratory impairment and disability. Although the causes of some of the diseases are known and the diseases may be preventable, the overall absolute burden of illness in the population is rising because of an enlarging population and newer therapeutic approaches. This is evident despite the lack of consistent and comparable data estimates for all diseases from national database resources. Where the data exist, it is evident that the cost related to the morbidity and mortality of these illnesses is substantial and consumes a significant proportion of health care expenditures. Both morbidity and mortality estimates, as well as cost estimates, are conservative and are likely underestimates of the true overall impact of ALD on the US economy.     

The involvement of the Golgi apparatus in the pathogenesis of amyotrophic lateral sclerosis, Alzheimer''s disease, and ricin intoxication

The purpose of this study was to assess the safety and feasibility of using standard and escalated doses of cyclophosphamide with doxorubicin, vincristine and prednisone (CHOP) plus granulocyte colony stimulating factor (G-CSF) to treat elderly patients who have advanced stage intermediate grade lymphoma. Consenting patients age > or = 65 years who had an acceptable performance status and adequate cardiac, renal and liver function were eligible for this Phase I study. G-CSF, 5 ug per kg, was given daily with each cycle from day 2 until neutrophil recovery of > or = 10 x 10(9)/L. Ten patients received standard CHOP; sequential cohorts of 5 patients were then to be given CHOP with cyclophosphamide doses of 900, 1050, 1200, and 1350 mg/m2. If 2 patients had dose limiting toxicity, cohorts were expanded to 10 patients; if 3 patients within a cohort had dose limiting toxicity, the previous dose level was considered the maximum tolerated dose of cyclophosphamide. Secondary outcomes were average relative received dose intensity, response, progression-free and overall survival, toxicity, hospitalizations and transfusions. Eight patients (80%) completed 6 cycles of standard CHOP plus G-CSF. Therapy was stopped prematurely in 2 patients due to pneumonia (1) and disease progression (1). Six of 11 patients (55%) given CHOP with cyclophosphamide 900 mg/m2 (CHOP-900) completed treatment. Therapy was stopped in 5 patients due to a toxic death from infection (1), cumulative fatigue (3), and pneumonitis (1). Further dose escalations were not attempted due to the inability to complete 6 treatment cycles in 45% of CHOP-900 cases. The received dose intensities of cyclophosphamide relative to standard CHOP measured over the actual time on therapy were 96% with standard CHOP and 115% with CHOP-900. At 3 years, progression free survival is 40% with standard CHOP and 82% with CHOP-900; overall survivals are 40% and 91% respectively. Neutropenia of < 1.0 x 10(9)/L occurred in 47% of treatment cycles with standard CHOP and in 77% with CHOP-900. In both groups, the mean duration of neutropenia was < 2 days. From these studies we conclude that, standard CHOP with G-CSF can be safely given to elderly patients. Escalating the dose of cyclophos