Particulate Fractions of Neisseria gonorrhoeae

Passage of gonococcal cells through a Ribi cell fractionator produced a mixture of protoplasm and cell particulates, the latter being separable in sucrose solutions. Separation of these particulates resulted in the detection of objects identified as cell walls and "plasts." The latter objects had an average diameter of 1.00 +/- 0.05 mum and consisted of spatially oriented granules surrounded by a membrane-like structure only. Cell wall structures were not observed with these plasts. Plasts were morphologically stable in distilled water and at low pH values. Although 50% more pressure was required to rupture plasts than whole cells, plast morphology was destroyed by organic solvents. Whole cell and plast morphology was examined by electron and phase microscopy, and certain correlations were made between structure and morphological stability. Cell wall antiserum reactivities were quantitatively different for plasts and cell walls. Serological reactivities of plasts were separable by sonic oscillation and differential centrifugation of the sonically treated material.

Localization of the high and low affinity [3H]ryanodine binding sites on the skeletal muscle Ca2+ release channel

The Ca2+ release channel of skeletal muscle sarcoplasmic reticulum is modulated in a biphasic manner by the plant alkaloid ryanodine and there are two distinct binding sites on this channel for ryanodine. The Ca2+ release channel is a homotetramer with a subunit of 5037 amino acids. The ability of sarcoplasmic reticulum membranes to bind [3H]ryanodine to the high affinity site is lost upon proteolysis with trypsin. [3H]Ryanodine, however, bound before proteolysis remains bound after trypsin digestion. If the high affinity site is first occupied with [3H]ryanodine and then 100 microM ryanodine is added to occupy the low affinity sites, almost all of [3H]ryanodine bound to the high affinity site remains bound after proteolysis. Proteolysis causes the solubilized Ca2+ release channel containing bound [3H]ryanodine to undergo four discrete shifts in sedimentation (30 S-->28 S-->26 S-->19 S-->14 S). Polypeptides having apparent molecular masses of 76, 66, 56, 45, 37, and 27 kDa can be identified in the 14 S complex. The 76-, 56-, 45-, and 27-kDa polypeptides have been partially sequenced from the NH2 terminus. In addition, the 76-, 66-, and 27-kDa fragments are recognized by an antibody to the last 9 amino acids at the carboxyl terminus of the skeletal muscle ryanodine receptor and the 76-, 66-, and 37-kDa fragments are recognized by an antibody to a peptide matching the sequence 4670-4685. The 56-kDa and the 45-kDa fragments are not Ca2+ release channel fragments. Both high and low affinity ryanodine binding sites are found in the 14 S complex and are, therefore, most likely located between Arg-4475 and the carboxyl terminus.

Replication of Colorado tick fever virus within human hematopoietic progenitor cells

Significant neutropenia, as well as thrombocytopenia and a mild anemia, occurs in patients infected with Colorado tick fever virus. In this study, human bone marrow CD34+ cells and KG-1a cells, a human hematopoietic progenitor cell line, were infected in vitro with Colorado tick fever virus. The time course and morphological appearance of viral replication in human progenitor cells were similar to those seen in erythroblasts and in HEL cells and suggest one possible mechanism for the clinical hematologic findings.

Congenital 21-hydroxylase deficiency as a new deletion mutation. Detection in a proband during subsequent prenatal diagnosis by HLA typing and DNA analysis

A child with 21-OH-def whose 9 weeks' pregnant mother was referred for prenatal diagnosis was found upon very careful histocompatibility testing to lack expression of any of his father's HLA antigens on his peripheral blood lymphocytes. The possibility of alternative paternity was considered to be extremely unlikely after additional genetic marker tests. The conclusion that the affected child's disease resulted from inheritance of a maternal CYP21B (21-OH) deletion and a de novo deletion in the paternal chromosome 6 segment that includes both the CYP21B (21-OH) and HLA genes was confirmed by subsequent DNA analysis using 21-OH, C4, DPB, and PCH6 probes. The presence of a heterozygous RFLP for DPB, the absence of a deletion for either CYP21B (21-OH) or C4 genes, and the presence of a paternal HLA antigen haplotype on the fetal cells additionally indicated that the fetus lacked the same deletion and could be predicted to be completely normal.

Electrophysiological analysis of the neural circuitry underlying opiate effects in the nucleus accumbens septi

Systemically administered opiates inhibit or excite spontaneously active single units of the nucleus accumbens septi (NAS) but do not affect fimbria-evoked NAS responses. However, microinjections of morphine to the dopamine cell bodies of the ventral tegmental area (VTA-M) do inhibit these evoked responses. Since systemic heroin can reverse the inhibitory effect of VTA-M on the fimbria-evoked NAS responses, systemic opiates might exert actions on other brain regions that oppose the inhibitory effect of VTA-M on the NAS. Evidence is provided indicating that this opposing action can arise from opiate actions at the ventral subiculum of the hippocampus.

Gamma interferon induces detectable serological and functional expression of DR and DP but not DQ antigens on cultured amniotic fluid cells

Cultured amniotic fluid cells, which are used for HLA typing studies for the prenatal diagnosis of HLA linked diseases and for prenatal determination of paternity, usually contain mixtures of fibroblastic and epithelioid cells. Cells of both types lack constitutive expression of HLA class II antigens, but these can be induced by pretreatment with gamma interferon. Both serological and functional studies indicate that detectable levels of DR and DP but not DQ antigens can be thereby induced. DR and DP cannot, however, be induced on chorionic villus cells.

The use of Epstein-Barr virus transformation for the establishment of class II positive cord blood cells for use in analysis of maternal sera

The use of Epstein-Barr virus transformed cord blood cells to detect maternal antibodies to neonatal class II DR and DQ antigens and to allotype the reacting cells is described.

HLA typing used with cultured amniotic and chorionic villus cells for early prenatal diagnosis or parentage testing without one parent's availability

Like fetal fibroblasts and amniotic fluid cells, cultured chorionic villus cells can also be HLA typed with selected typing sera after preincubation with gamma interferon to promote better antigen expression. A modified procedure now in use would also allow any of these cell types to be tested for the presence or absence of all known HLA A,B,C, and DR antigens with standard preplated typing trays. This procedure was used to confirm that an on-going pregnancy had resulted from the successful in vitro fertilization and implantation of an anonymous donor's ovum and could also be of major use in rape or artificial insemination cases when the identity of the possible father(s) is not known.

Mixed lymphocyte reactions for individuals with phenotypic identity for specific HLA-B,DR determinants: the role of linkage disequilibrium and of specific DR and other class II determinants

Although many patients who might benefit from therapeutic bone marrow transplantation lack HLA identical sibling donors, results from many centers now indicate that transplants involving donors other than identical siblings have been successful in a substantial number of cases. Most of these cases were selected because cells from the patient and donor were compatible in mixed lymphocyte culture. We have previously shown that the prediction of mixed lymphocyte culture nonreactivity by HLA-B,DR matching is far more successful if the matched donors shared antigen combinations known to possess significant positive linkage disequilibrium. We now also show that cells from donors with unrelated haplotypes having the specific DR determinants DR1, DR2, and DR3 are more likely than cells from donors with other haplotypes to be mutually compatible in mixed lymphocyte culture. However, even cells from donors with haplotypes with the highest levels of positive linkage disequilibrium frequently show significant mutual stimulation which can, in selected family studies, be attributed to determinants like SB that map between HLA-D/DR and GLO.

Absence of HLA association or linkage for variations in sensitivity to the odor of androstenone

Sensitivity to the odor of 5-androst-16-en-3-one (androstenone), a testosterone metabolite, shows wide variations among unrelated individuals. Analysis of correlations in sensitivity between monozygotic twin pairs, dizygotic twin pairs, and nontwin sib pairs now shows that at least a portion of this variation is genetically determined. However, although data from some mouse studies have suggested a relationship between olfaction and the murine histocompatibility system (H-2), we were unable to demonstrate any role of the human HLA system in explaining the wide individual variations in human sensitivity to androstenone. An additional analysis of HLA antigens among 61 human mating pairs also provided no evidence that HLA phenotypes play a role in human mating preference. These data fail to support a role for the human HLA system in the recognition of an odorant of potential biological significance.

HLA genotypes and HLA-linked genetic markers in Italian patients with classical 21-hydroxylase deficiency

HLA genotype and HLA-linked marker data for 40 unrelated patients from central Italy and 2 unrelated patients from Sardinia with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OH-def) were analyzed. The results confirm that the HLA-linked 21-OH-def gene is associated with several different HLA determinants and complete HLA haplotypes, although the only determinant with significantly increased frequency was the complement C2 allele C2B. The HLA antigens B8 and DR3 were found in significantly decreased frequencies. The haplotype A3, Cw6, Bw47, BfF, DR7, which is exceptionally rare in the general population but which has been found in many other 21-OH-def patients from diverse geographical origins, was also found in one of the Italian patients. This and other HLA haplotype associations found among the Italian patients may represent mutations that have occurred on HLA haplotypes with genetic linkage disequilibrium or, alternatively, may represent mutations that have not yet had time to become randomly associated with different HLA complex determinants. The marked negative associations with B8 and DR3 could, however, result from an interaction between the gene products of the HLA complex and the 21-OH-def phenotype.

Diagnosis of toxoplasmosis by electron microscopic fine-structural analysis

The analysis of fine structures by electron microscopic examination of ultrathin tissue sections permitted a diagnosis of toxoplasmosis in a fatal human case that would have gone undiagnosed by conventional methods. Examination of histologically prepared sections revealed organisms that were morphologically nondiagnostic. Fine-structural analysis showed the organisms to be 3 x 2 micrometer in size, to contain few micronemes, to contain as many as nine rhoptries, to possess an apical conoid, and to multiply by endodyogeny. The features corresponded to those observed in fine-structural analyses of Toxoplasma gondii grown in animals by Scholtyseck and Mehlhorn. Fine-structural analysis can be a valuable adjunct in the diagnosis of toxoplasmosis.