Properties of the reaction center of the thermophilic purple photosynthetic bacterium Chromatium tepidum

Reaction centers were purified from the thermophilic purple sulfur photosynthetic bacterium Chromatium tepidum. The reaction center consists of four polypeptides L, M, H and C, whose apparent molecular masses were determined to be 25, 30, 34 and 44 kDa, respectively, by polyacrylamide gel electrophoresis. The heaviest peptide corresponds to tightly bound cytochrome. The tightly bound cytochrome c contains two types of heme, high-potential c-556 and low-potential c-553. The low-potential heme is able to be photooxidized at 77 K. The reaction center exhibits laser-flash-induced absorption changes and circular dichroism spectra similar to those observed in other purple photosynthetic bacteria. Whole cells contain both ubiquinone and menaquinone. Reaction centers contain only a single active quinone; chemical analysis showed this to be menaquinone. Reaction center complexes without the tightly bound cytochrome were also prepared. The near-infrared pigment absorption bands are red-shifted in reaction centers with cytochrome compared to those without cytochrome.     

Influence of Physical Disruption on Growth of Attached Bacteria

Attached bacterial populations cultured without an exogenous carbon source or grown in conjunction with attached diatoms incorporated [³H]thymidine at a rate between four and five times lower than that of replicate bacterial populations which were dispersed before being assayed.     

Aspergillus myositis in a patient with a myelodysplastic syndrome

We present the case of an elderly man who, while being treated with corticosteroids for a myelodysplastic syndrome, developed myositis of the calf due to Aspergillus fumigatus. Despite therapy with amphotericin B the myositis failed to resolve and he died. At autopsy, a localized necrotizing myositis of the right calf was found with no evidence of disseminated Aspergillus infection. Myositis in the setting of disseminated candidiasis or cryptococcosis has been previously reported. This case is unique in that it is the first reported case of localized fungal myositis and of myositis caused by Aspergillus.     

Development of the nervous system of the pluteus larva of Strongylocentrotus droebachiensis

Summary Development of the nervous system of the pluteus larva of Strongylocentrotus droebachiensis was investigated using indirect immunofluorescence with antibodies against dopamine, GABA, and serotonin, and glyoxylic acid-induced fluorescence of catecholamines. Serotonergic cells first appear in full gastrulae; dopaminergic and GABAergic cells are present in early four-arm plutei. The number of neurons and the complexity of the nervous system increases through development of the pluteus. In the pluteus the dopaminergic component of the nervous system includes a ganglion in the lower lip of the mouth and a pair of ganglia at the base of the post-oral arms which extend axons along the base of the circumoral ciliary band. The distribution of cells visualized by glyoxylic acid-induced fluorescence is similar to that of dopaminergic cells. GABAergic neurons occur in the upper lip and in the wall of the esophagus. Serotonergic neurons are present in the lower lip; the pre-oral hood contains an apical ganglion which extends axons along the base of the epidermis overlying the blastocoel. The dopaminergic and GABAergic components of the nervous system are associated with effectors involved in feeding and swimming. The serotonergic component is not associated with any apparent effectors but may have a role in metamorphosis.     

ReducedS-adenosylmethionine: Protein-lysineN-methyltransferase activity (protein methylase III) in shiverer mutant mouse brain

Mice with the dysmyelinating mutation shiverer were studied by measuring the activity of two protein methylases and myelin marker enzymes in the brain. It was observed thatS-adenosylmethionine: protein-lysineN-methyltransferase (protein methylase III, EC. 2.1.1.43) activity is significantly reduced in phenotypically affected homozygous shiverer (shi/shi) mutant mouse brain compared to the unaffected heterozygous littermate brain. This reduction in enzyme activity is manifested mainly by reduced formation of trimethyllysine during the in vitro methylation of histone. In contrast, myelin marker enzymes such as 2,3-cyclic nucleotide 3-phosphohydrolase and 5-nucleotidase as well asS-adenosyl-methionine: protein-carboxylO-methyltransferase (protein methylase II, EC. 2.1.1.24) activities were not significantly affected in these strains of mice.     

Acquisition of a brief behavioral experience in the presence of neuron-specific and D2-CAM/N-CAM-specific antisera

The effect of intraventricular infusion of D2-CAM/N-CAM directed antibodies prior to the acquisition of a passive-avoidance paradigm is described. The antisera used in this study were the neuron specific anti-BPM and a D2-CAM/N-CAM specific serum, anti-D2. Anti-BPM reliably inhibited paradigm acquisition when recall was ascertained at 24 and 48 hours and no effect was noted with absorbed anti-BPM or in sham-operated animals. This effect was time-dependent and no inhibition of memory formation was noted when the antiserum was administered at 6 and 10 hours after training. In contrast, infusion of anti-D2 had no effect on paradigm acquisition. These findings are discussed in relation to the potential synaptogenic events associated with memory formation.     

Application of a new method for detecting the phenotype of target binding cells

Summary A new method was developed for detecting the phenotype of target binding cells (TBC) in a single-cell assay system. This methodology was evaluated during a clinical trial of recombinant interferon alfa-2a (rIFN alfa-2a) for the treatment of 10 metastatic renal cell carcinoma patients. Total TBC with K562 targets, HNK-1+ TBC, and HLA-DR+ TBC were quantitated during rIFN alfa-2a therapy. A significantly increased proportion of lymphocytes bound to target cells on day 9 of therapy bore the HNK-1 marker. This proportion subsequently declined to pretreatment levels. Total TBC paralleled the rise and fall in HNK-1+ TBC. HLA-DR+ TBC binding to targets remained constant and low throughout therapy. These findings suggest that rIFN alfa-2a early in therapy (day 9) caused the recruitment of additional HNK-1+ cells into binders. However, with continued therapy, this proportion reverts to pretreatment levels. The results of this clinical trial served to illustrate the ability of the modified single-cell assay system to detect TBC phenotype.Supported in part by Hoffman-La Roche, NIH grant CA 12582, and Jonsson Comprehensive Cancer Center grant CA 15866Dr. Figlin is a recipient of an American Cancer Society Junior Faculty Fellowship-JFCF 762-A     

Assignment of the prealbumin (PALB) gene (familial amyloidotic polyneuropathy) to human chromosome region 18q11.2–q12.1

Summary The assignment of the human prealbumin (PALB) gene to chromosome region 18q11–q12.1 has been achieved using a human genomic probe in the study of human-mouse somatic cell hybrids and by in situ hybridization. Because familial amyloidotic polyneuropathy was reported previously to be due to a mutation in prealbumin, it can be inferred that the gene for this disorder also maps to 18q11.2–q12.1.