Impact of the ''Back to Sleep'' campaign on sudden infant death syndrome in Minnesota

Diffuse axonal injury (DAI) was diagnoses according to axonal reaction proved as balls by Palmgren's silver impregnation and axonal lesions by immunohistochemical investigation of ubiquitin and low molecular weight neurofilaments (68 kD). Diffuse axonal injury was found in 16 cases from a group of 36 persons deceased of craniocerebral trauma (44%). Diagnosis was based on the presence of axonal retraction balls in 15 cases; the balls showed also a striking positivity with antibodies against ubiquitin and low molecular neurofilaments as well. In the last patient who died 10 hours after a head injury, too early for axonal retraction balls to be formed, diagnosis of DAI could be settled because of the presence of axonal swellings immunohistochemically positive for ubiquitin and neurofilaments. A control groups of 6 persons after sudden death showed both axonal widenings and swellings but their immunohistochemistry was negative. Immunohistochemical methods of proving ubiquitin and low molecular weight neurofilaments represent substantial contribution to diagnosis of diffuse axonal injury. Earlier phase of axonal lesions than in simple histology can be observed and histological diagnosis of axonal injury independently confirmed.     

Excessive breast self-examination among first-degree relatives of newly diagnosed breast cancer patients. High-Risk Breast Cancer Consortium

The influence of the primary antibody, the fixative, and the antigen unmasking technique on the method sensitivity of immunohistochemistry as a method for the identification of viral hemorrhagic septicemia (VHS) virus in paraffin-embedded specimens of naturally infected rainbow trout (Oncorhynchus mykiss) was examined. Fish (200-300 g) were collected during an outbreak of VHS. Parallel specimens from liver, spleen, kidney, and brain were fixed by immersion in 10% phosphate-buffered formalin, periodate-lysine-paraformaldehyde (PLP), Bouin's fluid, or absolute ethanol. Virus cultivation was also performed on parallel specimens, and the virus titer (TCID50/ml) was determined. Purified nucleocapsid protein (N-protein) of the virus was incorporated in an artificial antigen substrate polymerized bovine serum albumin), fixed as described above, and embedded in paraffin wax. Microwave unmasking was performed on formalin-, PLP-, and Bouin's fluid-fixed specimens. The presence of virus peptides in situ or N-protein in the artificial antigen substrates was visualized using an immunohistochemical method based on alkaline phosphatase or peroxidase and one polyclonal and five monoclonal polypeptide-specific antibodies. VHS virus was identified in situ in specimens with high virus titers (10(7-8) TCID50/ml) regardless of the fixative and without the need of an unmasking procedure. A pronounced masking effect was observed for the cross-linking formalin and PLP fixatives. Regardless of the primary antibodies used, there was a significantly higher epidemiologic sensitivity (the proportion of virus positive samples that tested positive by immunohistochemistry) using ethanol and Bouin's fluid compared with formalin and PLP (P < 0.05). At 10(5) TCID50/ml, the average sensitivity reached 0.5, and at > or = 10(6) TCID50/ml, sensitivity was 0.9. Unmasking procedures showed a moderate effect and did not result in significantly higher epidemiologic sensitivity (P = 0.17), There was great variation for the different monoclonal antibodies/antigens and fixatives. Sensitivity studies on antigen substrates were in accordance with results of in situ studies that showed the highest sensitivity for ethanol and Bouin's fluid. Virus cultivation was more sensitive than immunohistochemistry. This study showed that the fixative and the primary antibody both influence method sensitivity and that VHS virus antigens concealed during fixation are difficult to reexpose. Immunostaining for VHS virus should be performed with monoclonal antibodies specific for the N-protein, and tissue samples should be fixed in either ethanol or Bouin's fluid. Immunohistochemistry is specific but is less sensitive than virus cultivation. Immunostaining for VHS virus can be a valuable supplement to virus cultivation during acute outbreaks of disease.     

Stress and dominance in a social fish

Many aspects of reproductive physiology are subject to regulation by social interactions. These include changes in neural and physiological substrates of reproduction. How can social behavior produce such changes? In experiments reported here, we manipulated the social settings of teleost fish and measured the effect (1) on stress response as reflected in cortisol production, (2) on reproductive potential as measured in production of the signaling peptide, gonadotropin-releasing hormone, and (3) on reproductive function measured in gonad size. Our results reveal that the level of the stress hormone cortisol depends critically on both the social and reproductive status of an individual fish and on the stability of its social situation. Moreover, the reproductive capacity of an individual fish depends on these same variables. These results show that social encounters within particular social contexts have a profound effect on the stress levels as well as on reproductive competence. Social behavior may lead to changes in reproductive state through integration of cortisol changes in time. Thus, information available from the stress pathway may provide socially relevant signals to produce neural change.     

Quantitation of human cytomegalovirus (HCMV) DNA in cerebrospinal fluid by competitive PCR in AIDS patients with different HCMV central nervous system diseases

The current study was designed to quantitate human cytomegalovirus (HCMV) DNA in cerebrospinal fluid (CSF) of persons with AIDS with specific HCMV-related CNS disease. DNA present in CSF obtained from AIDS patients was initially detected by a qualitative PCR procedure and then quantitated using a competitive PCR assay. In a group of 21 AIDS patients with HCMV-related CNS disease, 12 patients with HCMV polyradiculopathy had a mean +/- SEM of 11,982 +/- 4,480 copies/microliters in their CSF compared to 1,747 +/- 929 for 9 patients with HCMV encephalitis p = 0.017). Of the 14 patients with > 1,000 copies/microliters of HCMV DNA in CSF, 11(79%) had HCMV polyradiculopathy including all 3 with > 10,000 copies/microliters. Ganciclovir treatment of 3 patients with HCMV-related CNS disease was associated with a decline in HCMV DNA detectable within CSF. These data indicate that quantities of HCMV DNA in CSF are higher in persons with HCMV-related polyradiculopathy than encephalitis, and that quantitation of HCMV DNA can be useful in monitoring antiviral therapy.     

Antigenic structure of soluble herpes simplex virus (HSV) glycoprotein D correlates with inhibition of HSV infection

Soluble forms of herpes simplex virus (HSV) glycoprotein D (gD) block viral penetration. Likewise, most HSV strains are sensitive to gD-mediated interference by cells expressing gD. The mechanism of both forms of gD-mediated inhibition is thought to be at the receptor level. We analyzed the ability of different forms of soluble, truncated gD (gDt) to inhibit infection by different strains of HSV-1 and HSV-2. Strains that were resistant to gD-mediated interference were also resistant to inhibition by gDt, thereby suggesting a link between these two phenomena. Virion gD was the major viral determinant for resistance to inhibition by gDt. An insertion-deletion mutant, gD-1(delta 290-299t), had an enhanced inhibitory activity against most strains tested. The structure and function of gDt proteins derived from the inhibition-resistant viruses rid1 and ANG were analyzed. gD-1(ridlt) and gD-1(ANGt) had a potent inhibitory effect on plaque formation by wild-type strains of HSV but, surprisingly, little or no effect on their parental strains. As measured by quantitative enzyme-linked immunosorbent assay with a diverse panel of monoclonal antibodies, the antigenic structures of gD-1(rid1t) and gD-1(ANGt) were divergent from that of the wild type yet were similar to each other and to that of gD-1 (delta 290-299t). Thus, three different forms of gD have common antigenic changes that correlate with enhanced inhibitory activity against HSV. We conclude that inhibition of HSV infectivity by soluble gD is influenced by the antigenic conformation of the blocking gDt as well as the form of gD in the target virus.     

Rancinamycins I, II, III and IV structural studies

Rancinamycins are secondary metabolites produced by Streptomyces lincolnensis in a sulfur-depleted culture medium. The structures (except stereochemistry) of the main components of the rancinamycin-complex were determined by the use of IR, UV, PMR, and CMR spectra.