Relationship quality moderates the effect of social support given by close friends on cardiovascular reactivity in women

We examined the role of the type of support provided, gender of support provider, and relationship quality in predicting how social support might influence cardiovascular reactivity during acute stress in women. A group of 88 women received either emotional, instrumental, or no support from a close female or male friend while performing a series of speech tasks. Results suggest that the effectiveness of social support for women depended primarily on the quality of the friendship (i.e., purely positive, or ambivalent). More specifically, women who interacted with a female, ambivalent friend had the largest changes in diastolic blood pressure, total peripheral resistance (TPR), and pre-ejection period compared to the other conditions. Furthermore, receiving emotional support from a purely positive friend was related to lower increases in cardiac output (CO) compared to a no-support condition. In contrast, receiving emotional support from an ambivalent friend was related to larger increases in CO and only small changes in TPR when compared to individuals in the no-support condition. These data are discussed in light of the psychosocial processes underlying social support effects in women, and the importance of a more comprehensive view of how close relationships influence cardiovascular function. This research was generously supported by Grant1 R01 MH58690-01 from the National Institute of Mental Health awarded to Bert N. Uchino.     

Identification of vaccine candidate peptides in the NcSRS2 surface protein of Neospora caninum by using CD4+ cytotoxic T lymphocytes and gamma interferon-secreting T lymphocytes of infected holstein cattle

Previously, our laboratory showed that Holstein cattle experimentally infected with Neospora caninum develop parasite-specific CD4+ cytotoxic T lymphocytes (CTL) that lyse infected, autologous target cells through a perforin-granzyme pathway. To identify specific parasite antigens inducing bovine CTL and helper T-lymphocyte responses for vaccine development against bovine neosporosis, the tachyzoite major surface proteins NcSAG1 and NcSRS2 were targeted. In whole tachyzoite antigen-expanded bovine T-lymphocyte lines, recombinant NcSRS2 induced potent memory CD4+- and CD8+-T-lymphocyte activation, as indicated by proliferation and gamma interferon (IFN-gamma) secretion, while recombinant NcSAG1 induced a minimal memory response. Subsequently, T-lymphocyte epitope-bearing peptides of NcSRS2 were mapped by using overlapping peptides covering the entire NcSRS2 sequence. Four experimentally infected cattle with six different major histocompatibility complex (MHC) class II haplotypes were the source of immune cells used to identify NcSRS2 peptides presented by Holstein MHC haplotypes. NcSRS2 peptides were mapped by using IFN-gamma secretion by rNcSRS2-stimulated, short-term T-lymphocyte cell lines, IFN-gamma enzyme-linked immunospot (ELISPOT) assay with peripheral blood mononuclear cells, and 51Cr release cytotoxicity assay of rNcSRS2-stimulated effector cells. Four N. caninum-infected Holstein cattle developed NcSRS2 peptide-specific T lymphocytes detected ex vivo in peripheral blood by IFN-gamma ELISPOT and in vitro by measuring T-lymphocyte IFN-gamma production and cytotoxicity. An immunodominant region of NcSRS2 spanning amino acids 133 to 155 was recognized by CD4+ T lymphocytes from the four cattle. These findings support investigation of subunit N. caninum vaccines incorporating NcSRS2 gene sequences or peptides for induction of NcSRS2 peptide-specific CTL and IFN-gamma-secreting T lymphocytes in cattle with varied MHC genotypes.     

Examination of Streptococcus mutans for immunoglobulin G Fc reactivity.

Representative strains of oral streptococci were tested for Fc immunoglobulin G (IgG) reactivity by two different techniques, agglutination of rabbit-IgG sensitized sheep erythrocytes and uptake of human and rabbit 125I-radiolabeled IgG. None of the S. mutans serotypes a through e reacted with the Fc region of either human or rabbit IgG. Additionally, other streptococci such as S. sanguis, S. salivarius, S. faecalis, and S. mitis failed to show appreciable Fc reactivity as assayed by these techniques. The group A, C, and G streptococci, previously shown to possess Fc reactivity, proved to be reactive in these experiments, as did a protein A-containing strain of Staphylococcus aureus.     

Trends in HIV prevalence among public sexually transmitted disease clinic attendees in the Western region of the United States (1989-1999)

OBJECTIVES: Using data from anonymous unlinked testing of routinely collected sera, trends in HIV are compared among sexually transmitted disease patients in 4 Western urban centers. METHODS: Between 1989 and 1999, remnant sera obtained for routine syphilis testing from 256,819 patient visits to Denver, Los Angeles, San Francisco, and Seattle clinics were tested for HIV antibodies in an unlinked survey. HIV antibody test results were linked to anonymous demographic and risk information abstracted from the medical record. RESULTS: Overall cumulative HIV seroprevalences among women and among men who had sex exclusively with women were < or = 2%, declined over time, and did not exceed 8% among those who injected drugs. In contrast, cumulative HIV seroprevalences among men who have sex with men ranged from 13% in Seattle to 30% in San Francisco and declined a mean of 2.1% (95% CI, 1.6, 2.6) to 2.8% (CI 2.6, 3.1) per year, after adjustment. CONCLUSIONS: HIV infection declined over time across counties. Relative levels of HIV differed little by demographic and behavioral risk group despite differences in the severity of each county's epidemic. Because of the unique contribution of unlinked serosurveillance studies in monitoring these trends, their reinstitution in high-risk settings should be considered.     

Fornix transection impairs conditional visuomotor learning in tasks involving nonspatially differentiated responses.

Rhesus monkeys learned a series of conditional visuomotor associations involving two-dimensional "objects" that instructed one of three responses: tapping a touch screen, steady contact with the screen for a brief period, or steady contact for a longer period. Relative to controls, fornix-transected monkeys were impaired in the acquisition of new associations and in the retention of preoperatively learned ones. These findings challenge the view that the hippocampal system participates in associative learning only when spatial information is relevant to either the stimulus or the response.     

Intertubular growth in pure seminomas: associations with poor prognostic parameters

Clinical stage I seminomas are effectively treated with surgery raising concerns as to when to give adjuvant radiation therapy given the risk of secondary malignancies. A recent randomized trial found tumor size and rete testis invasion to be the strongest predictors of relapse in clinical stage I seminomas. These 2 parameters may be surrogate measures of tumor volume. Intertubular seminoma (ITS) of the testis describes the presence of neoplastic germ cells within the interstitium of the testis. These cells are detected away from the main macroscopic mass. Because ITS can infiltrate in a 3-dimensional fashion, it may also represent a measure of tumor volume not usually noted in standard pathology reporting. The goal of this study was to determine the incidence of ITS in pure seminomas and its association with other prognostic parameters. One hundred twenty consecutive pure seminomas surgically removed between 1998 and 2003 were evaluated. ITS was defined as the presence of an interstitial or intertubular growth pattern of tumor cells, which was noncontiguous with the main tumor and present at least 3 high-power fields away from the tumor mass. The average tumor size was 3.4 cm. Of the entire cohort of patients, which included pathological stages T1 through T3, 11% had invasion through the tunica albuginea, 51% had rete testis invasion, 51% had lymphovascular invasion, 93% had associated intratubular germ-cell neoplasia, and 36% had ITS. ITS was significantly associated with rete testis invasion ( P = .001). Logistic regression analysis looking at ITS, tumor size, patient age, and lymphovascular invasion revealed that only ITS was associated with rete testis invasion (RR, 4.1, P < .0001). ITS is present in a significant proportion of pure seminomas and has a significant association with rete testis invasion. The presence of ITS may therefore be an important prognostic factor, not only because it alters the calculated size of the tumor but also because it has an association with rete testis invasion.     

Fuel kinetics during intense running and cycling when fed carbohydrate

On two occasions, six well-trained, male competitive triathletes performed, in random order, two experimental trials consisting of either a timed ride to exhaustion on a cycle ergometer or a run to exhaustion on a motor-driven treadmill at 80% of their respective peak cycling and peak running oxygen (VO_2max) uptakes. At the start of exercise, subjects drank 250 ml of a 15 g·100 ml^–1 w/v [U-¹⁴C]glucose solution and, thereafter, 150 ml of the same solution every 15 min. Despite identical metabolic rates [VO₂ 3.51 (0.06) vs 3.51 (0.10) 1·min^–1; values are mean (SEM) for the cycling and running trials, respectively], exercise times to exhaustion were significantly longer during cycling than running [96 (14) vs 63 (11) min; P < 0.05]. The superior cycling than running endurance was not associated with any differences in either the rate of blood glucose oxidation [3.8 (0.1) vs 3.9 (0.4) mmol· min^–1], or the rate of ingested glucose oxidation [2.0 (0.1) vs 1.7 (0.2) mmol· min^–1] at the last common time point (40 min) before exhaustion, despite higher blood glucose concentrations at exhaustion during running than cycling [7.0 (0.9) vs 5.8 (0.5) mmol·1^–1; P < 0.05]. However, the final rate of total carbohydrate (CHO) oxidation was significantly greater during cycling than running [24.0 (0.8) vs 21.7 (1.4) mmol C₆·min^–1; P < 0.01]. At exhaustion, the estimated contribution to energy production from muscle glycogen had declined to similar extents in both cycling and running [68 (3) vs 65 (5)%]. These differences between the rates of total CHO oxidation and blood glucose oxidation suggest that the direct and/or indirect (via lactate) oxidation of muscle glycogen was greater in cycling than running.     

Class II defective avian sarcoma viruses: Comparative analysis of genome structure

The genomes of class II avian sarcoma viruses PRCII, PRCII-p, PRCIV, and Fujinami sarcoma virus (FSV), were studied by oligonucleotide fingerprinting, heteroduplex mapping, and nucleic acid hybridization. All of these viruses are genetically defective and have a small RNA genome between 4.5 and 6.1 kilobases (kb) in length. They contain helper-related sequences at both the 5′- and 3′-ends, but most of the retroviral sequences in the middle of the genome are deleted. In place of this deleted information, a contiguous stretch of transformation-specific sequences, termed fps, is found. These putative oncogenic sequences are about 1.2 kb in PRCII, and those in PRCII-p and PRCIV are roughly 2.9 kb. From the analysis of oligonucleotides, it appears that the fps sequences of PRCII represent a subset of those of PRCII-p. Most of the additional sequences present in PRCII-p but absent from PRCII are at the 5′-half of fps. The helper-related sequences in PRCII and PRCII-p are almost indistinguishable, except that PRCII-p contains slightly more retroviral information at the 3′-end of the genome. Therefore, it is possible that PRCII has been derived by deletion from PRCII-p. By contrast, PRCII-p and PRCIV were found to contain identical fps sequences, but their helper-related sequences have diverged substantially. These two sarcoma viruses either represent two independent isolates or, if derived from a single isolate, they have undergone extensive mutation and recombination with diverse avian retroviruses. FSV was found to differ to a greater extent from other class II sarcoma viruses in both helper-related and fps sequences. The difference in fps sequences is localized in the 5′-half of that region. Considering the variation in fps among all members of class II avian sarcoma viruses, it appears that the 3′-half of that genetic region is more conserved than the 5′-half.