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Biomedical subjects

S Barrick

Publications and source records attributed to S Barrick.

7 recordsLinked to original sources
PubMed2004

Alterations in P2X and P2Y purinergic receptor expression in urinary bladder from normal cats and cats with interstitial cystitis.

Purinergic mechanisms appear to be involved in motor as well as sensory functions in the urinary bladder. ATP released from efferent nerves excites bladder smooth muscle, whereas ATP released from urothelial cells can activate afferent nerves and urothelial cells. In the present study, we used immunohistochemical techniques to examine the distribution of purinoceptors in the urothelium, smooth muscle, and nerves of the normal cat urinary bladder as well as possible changes in the expression of these receptors in cats with a chronic painful bladder condition termed feline interstitial cystitis (FIC) in which ATP release from the urothelium is increased. In normal cats, a range of P2X (P2X(1), P2X(2), P2X(3), P2X(4), P2X(5), P2X(6), and P2X(7)) and P2Y (P2Y(1), P2Y(2), and P2Y(4)) receptor subtypes was expressed throughout the bladder urothelium. In FIC cats, there is a marked reduction in P2X(1) and loss of P2Y(2) receptor staining. Both P2X(3) and P2Y(4) are present in nerves in normal cat bladder, and no obvious differences in staining were detected in FIC. Smooth muscle in the normal bladder did not exhibit P2Y receptor staining but did exhibit P2X (P2X(2), P2X(1)) staining. In the FIC bladder smooth muscle, there was a significant reduction in P2X(1) expression. These findings raise the possibility that purinergic mechanisms in the urothelium and bladder smooth muscle are altered in FIC cats. Because the urothelial cells appear to have a sensory function in the bladder, it is possible that the plasticity in urothelial purinergic receptors is linked with the painful bladder symptoms in IC.

Adenosine Triphosphate↗
PubMed2002

Altered urinary bladder function in mice lacking the vanilloid receptor TRPV1.

In the urinary bladder, the capsaicin-gated ion channel TRPV1 is expressed both within afferent nerve terminals and within the epithelial cells that line the bladder lumen. To determine the significance of this expression pattern, we analyzed bladder function in mice lacking TRPV1. Compared with wild-type littermates, trpv1(-/-) mice had a higher frequency of low-amplitude, non-voiding bladder contractions. This alteration was accompanied by reductions in both spinal cord signaling and reflex voiding during bladder filling (under anesthesia). In vitro, stretch-evoked ATP release and membrane capacitance changes were diminished in bladders excised from trpv1(-/-) mice, as was hypoosmolality-evoked ATP release from cultured trpv1(-/-) urothelial cells. These findings indicate that TRPV1 participates in normal bladder function and is essential for normal mechanically evoked purinergic signaling by the urothelium.

Acetic Acid↗
PubMed2001

Chronic inflammation with increased human immunodeficiency virus (HIV) RNA expression in the vaginal epithelium of HIV-infected Thai women.

Thai residents have a greater risk of heterosexual transmission of human immunodeficiency virus (HIV) than do US residents. To analyze host factors associated with heterosexual transmission, vaginal epithelial biopsies from HIV-seropositive Thai and US women were evaluated for tissue virus load and histologic makeup. In all, 84% of Thai and 14% of US women exhibited a chronic inflammatory T cell infiltrate in the vaginal epithelium. In Thai tissue, the infiltrate was associated with elevated levels of HIV RNA in the epidermis. Uninfected Thai women also had vaginal epithelial inflammation. Inflammation did not correlate with sexually transmitted diseases or HIV disease stage. The higher rates and increased risk of heterosexual transmission in Thailand may be due to chronic inflammation at the site where the virus is transmitted, which leads to the accumulation of activated T cells. Such cells might act as targets for initial viral infection and subsequently as reservoirs that support efficient transmission.

Adult↗
PubMed1999

Performance of the Affymetrix GeneChip HIV PRT 440 platform for antiretroviral drug resistance genotyping of human immunodeficiency virus type 1 clades and viral isolates with length polymorphisms.

The performance of a silica chip-based resequencing method, the Affymetrix HIV PRT 440 assay (hereafter referred to as the Affymetrix assay), was evaluated on a panel of well-characterized nonclade B viral isolates and on isolates exhibiting length polymorphisms. Sequencing of human immunodeficiency virus type 1 (HIV-1) pol cDNAs from clades A, C, D, E, and F resulted in clade-specific regions of base-calling ambiguities in regions not known to be associated with resistance polymorphisms, as well as a small number of spurious resistance polymorphisms. The Affymetrix assay failed to detect the presence of additional serine codons distal to reverse transcriptase (RT) codon 68 that are associated with multinucleoside RT inhibitor resistance. The increasing prevalence of non-clade B HIV-1 strains in the United States and Europe and the identification of clinically relevant pol gene length polymorphisms will impact the generalizability of the Affymetrix assay, emphasizing the need to accommodate this expanding pool of pol genotypes in future assay versions.

Acquired Immunodeficiency Syndrome↗
PubMed1977

Clinical and pathogenetic studies of Medical Lake macaque virus infections in cynomolgus monkeys (simian varicella).

The Medical Lake macaque (MLM) virus produced varicelliform eruptions in cynomolgus monkeys. Not all experimentally infected monkeys developed overt disease; viremia was found, and specific antibodies were detected. Specific lesions were found in skin, lymph nodes, and spleen. Focal inflammatory lesions were present in liver, pancreas, and lung (after intratracheal instillation of virus). MLM virus was recovered from these and other organs. The temporal movements of MLM virus in and out of primary and secondary target organs remained partially unsolved. MLM virus is related to the Wu strain of varicella virus.

Animals↗
PubMed1975

The pathogenesis of simian varicella virus in cynomolgus monkeys.

The MLM herpesvirus is infectious for cynomolgus monkeys. The disease in this species, possibly modulated by preinoculation antibody resembles human varicella. Virus has been recovered from blood during the early incubation period, and from liver, lymph nodes, kidney, bladder and urine during the eruptive period of infection. The major target organs were skin and liver; specific pathological changes developed in both. Appropriate antibody responses, including those to Herpesvirus varicellae followed infections mounted by parenteral inoculation of cynomolgus monkeys.

Animals↗