Restricted tissue expression pattern of a novel human rasGAP-related gene and its murine ortholog

The mammalian rasGAPs constitute a group of widely expressed proteins involved in the negative regulation of ras-mediated signaling. In this study we have isolated a novel human gene, RASAL (Ras GTPase-activating-like) and its murine ortholog, MRASAL which are most similar to the GAP1 family of rasGAP proteins, based upon the presence and organization of specific conserved domains. Full-length human and murine mRNA sequences are predicted to encode 804 and 799 amino acid polypeptides, respectively. Sequence analysis of these two proteins revealed the presence of two N-terminal calcium-dependent phospholipid binding C2 domains, a conserved GAP related domain (GRD) and a C-terminal pleckstrin homology (PH) domain. Northern blot and mRNA in situ hybridization analyses indicate that RASAL, in contrast to other mammalian rasGAP proteins, has a limited expression pattern; RASAL is highly expressed in the follicular cells of the thyroid and the adrenal medulla and expressed at lower levels in brain, spinal cord and trachea. Human RASAL has been localized by radiation hybrid mapping to chromosome 12q23-24.

Surface analysis of human plasma fibronectin adsorbed to commercially pure titanium materials

Protein binding on metallic implant surfaces, such as titanium, is governed by the physico-chemical nature of the metallic surface. Human plasma fibronectin (HPF) is an important matrix glycoprotein that mediates cell and protein attachment to each other or to the extracellular matrix present during wound healing. The objective of this study was to investigate the adsorption of HPF onto polished commercially pure titanium (cpTi) by using atomic force microscopy (AFM) and electron spectroscopy for chemical analysis (ESCA) and to measure the resultant surface contact angle before and after HPF binding. Two types of cpTi disks, one highly polished in our laboratory (HSS) and one commercially prepared (31), were reacted with HPF solutions of varying concentrations (1 microg/mL-10 ng/mL). ESCA survey spectra of samples coated with 1 microg/mL of fibronectin showed an increase in organic nitrogen and carbon compared with uncoated controls. Contact angle measurements of HSS and 31 cpTi disks showed no significant difference in average contact angle (36.3 degrees +/- 3.5 and 39.1 degrees +/- 3.1) despite differences in local root mean square (RMS) surface roughness (4.45 +/- 0.46 nm and 22.37 +/- 4.17 nm) as measured by AFM. Images obtained by AFM showed that 31 specimens were more irregular, with large parallel polishing grooves. Adsorbed HPF appeared in a globular form with an average length of 16.5 +/- 1.0 nm, a height of 2.5 +/- 0.5 nm, and a width of 9.6 +/- 1.2 nm. Fibronectin coating on both HSS and 31 cpTi specimens resulted in a significant increase in hydrophobicity compared to uncoated specimens. These results indicate the significance of HPF on cpTi and may explain how cpTi implants function in situ.

Transabdominal intra-amniotic endoscopic assessment of previable premature rupture of membranes

OBJECTIVE

Our purpose was to describe the endoscopic characteristics of the site of rupture in vivo in patients with spontaneous premature rupture of membranes.

STUDY DESIGN

Patients with preterm premature rupture of membranes between 16 and 26 weeks of gestation, without evidence of intra-amniotic infection, and with a normal karyotype underwent transabdominal endoscopic examination of the amniotic cavity. Subsequently, an amniopatch of a combination of platelets and cryoprecipitate to seal the membrane defect was administered. The study was approved by the Institutional Review Board of St. Joseph's Hospital in Tampa, Florida, and all patients gave written informed consent.

RESULTS

Four patients underwent endoscopic examination and amniopatch administration; three had spontaneous preterm premature rupture of membranes, and in the other the membranes ruptured after an early amniocentesis. The location of the site of rupture was over the internal os in the 3 cases with spontaneous preterm premature rupture of membranes. This area was normal in the patient with iatrogenic preterm premature rupture of membranes. The longer the time between preterm premature rupture of membranes and fetoscopy, the larger and less defined was the site of rupture. The amniopatch restored amniotic integrity for a maximum of 72 hours.

CONCLUSIONS

This is the first in vivo endoscopic visualization of the site of spontaneous rupture of membranes from within the uterine cavity. The defect is located over the internal cervical os in patients with spontaneous preterm premature rupture of membranes. There appear to be time-related changes in the morphologic characteristics of the site of rupture. Endoscopic visualization of the site of rupture has the potential for improving our understanding of spontaneous preterm premature rupture of membranes and in the development of possible therapeutic alternatives.

Selecting keywords: helping others find your article

Keywords or indexing words help the intended audience of your article both directly and indirectly. Directly, they help the reader identify the topics covered. Indirectly, they help indexers identify the subject headings used in journal indexes and databases. This article reviews the indexing process, provides a step-by-step way of identifying keywords for your article, and identifies some common pitfalls to avoid.

Mitochondrial DNA sequencing of shed hairs and saliva on robbery caps: sensitivity and matching probabilities

Sequencing of mitochondrial DNA (mtDNA) has been used for human identification based on teeth and skeletal remains. Here, we describe an amplification system for the mtDNA control region (D-loop) suited for the analysis of shed hair, which constitutes the most common biological evidence material in forensic investigations. The success rate was over 90% when applied to evidence materials such as shed hair, saliva stains and saliva on stamps. The analysis of evidence materials collected from three similar robberies revealed the presence of mtDNA sequences identical to those of the suspects in the three crimes. The use of mtDNA control region sequences for individual identification was evaluated. The probability of identity by chance for the mtDNA types of the suspects in the robberies was found to vary between Pr = 0.017 - < 0.0017, depending on the reference population used, emphasizing the need for large population databases to obtain the appropriate estimate.

Complications of use of intrauterine devices among HIV-1-infected women

BACKGROUND

A WHO expert group and the International Planned Parenthood Federation recommend against use of intrauterine devices (IUDs) in HIV-1-infected women based on theoretical concerns about pelvic infection and increased blood loss. We investigated whether the risk of complications after IUD insertion is higher in HIV-1-infected women than in non-infected women.

METHODS

649 (156 HIV-1 infected 493 non-infected) women in Nairobi, Kenya, who requested and met local eligibility criteria for insertion of an IUD were enrolled. We gathered information on IUD-related complications, including pelvic inflammatory disease, removals due to infection, pain, or bleeding, expulsions, and pregnancies at 1 and 4 months after insertion. Patients' HIV-1 status was masked from physicians.

FINDINGS

Complications were identified in 48 of 615 women (11 [7.6%] HIV-1-infected women, 37 [7.9%] non-infected). Incident pelvic inflammatory disease (two [1.4%] HIV-1 infected, one [0.2%] non-infected) and infection-related complications (any tenderness, removal of IUD for infection or pain; ten [6.9%] HIV-1 infected, 27 [5.7%] non-infected) were also rare and similar in the two groups. Complication rates were similar by CD4 (immune) status. Multivariate analyses suggested no association between HIV-1 infection and increased risks for overall complications (odds ratio 0.8 [95% CI 0.4-1.7]) or infection-related complications (1.0 [0.5-2.3]), adjusted for marital status, study site, previous IUD use, ethnic origin, and frequency of sexual intercourse, but a slight increase cannot be ruled out.

INTERPRETATION

Our data suggest that IUDs may be a safe contraceptive method for appropriately selected HIV-1-infected women with continuing access to medical services.

Contrasting effects of ultraviolet A1 and ultraviolet B exposure on the induction of tumour necrosis factor-alpha in human skin

Ultraviolet B (UVB) irradiation of the skin causes immunosuppression which is relevant to the induction of skin cancer. The mechanism of this immunomodulation is unclear but various regulatory molecules have been implicated, including cis-urocanic acid (cis-UCA) and the cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin 10 (IL-10). Whether ultraviolet A (UVA) induces similar changes has not been investigated fully. We studied the effect of in vivo UVB and long-wave UVA (UVA1) exposure on the induction of TNF-alpha, IL-10 and cis-UCA in human skin. Volunteers were irradiated with three minimal erythema doses (MED) of UVB or UVA1. At different times after irradiation, suction blisters were raised from irradiated and from non-irradiated (control) skin. The TNF-alpha and IL-10 protein concentration, and the percentage of cis-UCA in the blister fluid, were then determined. UVB irradiation of human skin led to a rapid and significant increase in TNF-alpha concentration in suction-blister fluid, with maximal values 6 h after irradiation (n = 6, P < 0.05). In contrast, UVA1 irradiation led to a decrease in TNF-alpha concentration in the suction-blister fluid compared with non-irradiated skin, with the lowest values 6 h after irradiation (n = 6, P < 0.05). Both UVB and UVA1 exposure of the skin induced a slight increase in IL-10 concentration. However, the increase in IL-10 was only significant after UVB irradiation (UVB, n = 6, P < 0.05; UVA, n = 7, P < 0.1). As previously shown, both UVB and UVA1 result in the photo-isomerization of trans-UCA and an increased percentage of cis-UCA was found in the suction-blister fluid. Thus the results show differential effects of UVB and UVA1 irradiation on the induction of immunoregulatory molecules, which may help to explain the variation in immune responses after UVB and UVA1 exposure of human skin.

Phenotypic characterization and analysis of allogeneic T cell responses in ZAP-70 dominant negative transgenic mice

Antigen stimulation of T cells results in a series of biochemical events including the interaction of both SH2 domains of ZAP-70 with phosphorylated ITAMS on the T cell receptor. In order to study the physiological relevance of decreasing native ZAP-70-SH2 interaction in vivo, we generated transgenic mice expressing a T cell-specific, dominant negative form of ZAP-70 consisting of only the tandem SH2 domains (ZAP-NC). Phenotypically, these animals had a comparable distribution of lymphocyte subsets in the thymus and spleen compared with the wild-type (WT) controls. However, examination of peripheral blood revealed a slow but progressive decrease in the number of lymphocytes, particularly CD4+ cells, with age (17% reduction by 3 months, 58% reduction by 6 months). Allogeneic responses were then evaluated in vitro as well as in vivo using a subcutaneous sponge matrix implant. Although spleen cells cultured for 4 days in vitro with alloantigen developed normal functional responses, allogeneic responses generated in vivo within a subcutaneous sponge matrix were impaired. This was characterized by a depression in cytotoxic T lymphocyte (CTL) activity, a 82% reduction in the frequency of helper T cells, and a 78% reduction in the capacity of sponge-infiltrating lymphocytes to produce IL-2 in response to secondary antigen stimulation. These results indicate that although overt lymphocyte development and in vitro function were unremarkable, expression of a truncated ZAP-70 affected the in vivo survival of peripheral lymphocytes and altered the in vivo generation of functional activity to alloantigen.

Overexpression of the angiogenic factor platelet-derived endothelial cell growth factor/thymidine phosphorylase in psoriatic epidermis

Considerable evidence indicates that the microvascular changes observed in psoriasis are a result of angiogenesis. Vascular proliferation is driven by the local production of molecules which have angiogenic activity. Platelet-derived endothelial cell growth factor/thymidine phosphorylase (PDECGF/TP) is a potent angiogenic factor active in in vivo angiogenesis assays and overexpressed in several tumour types. We have demonstrated by ribonuclease protection analysis a consistently high degree of PDECGF/TP mRNA production in lesional psoriatic skin, while immunohistochemical studies revealed strong PDECGF/TP immunoreactivity in lesional epidermis, with nuclear staining present in basal keratinocytes and cytoplasmic immunoreactivity in suprabasal layers. Non-lesional skin showed minimal PDECGF/TP mRNA production and weak epidermal immunostaining. These results indicate a potential role for PDECGF/TP in the pathophysiology of psoriasis, and reveal a target for antiangiogenesis therapy in the treatment of this disease.

Cryptic self-incompatibility in tristylous Decodon verticillatus (Lythraceae)

There is growing evidence that many self-compatible plants control the level of self-fertilization with postpollination processes that give a siring advantage to cross pollen over self pollen through "cryptic self-incompatibility" (CSI). Previous marker-gene experiments with self-compatible, tristylous Decodon verticillatus (Lythraceae) have demonstrated a siring advantage to cross pollen, though the extent to which this advantage results from prezygotic discrimination vs. early acting inbreeding depression is not clear. Here, we provide evidence that prezygotic mechanisms are involved in this siring advantage by comparing pollen tube numbers at various times following cross- and self-pollination conducted in a natural population. In the 24 h following pollination, cross pollen yielded almost twice as many pollen tubes at various positions in the style compared to self pollen. After 36 and 48 h, the difference between pollen types had disappeared, suggesting that the advantage to cross pollen results from differences in the rate of pollen germination and;clor tube growth rather than pollen tube attrition. Comparison of tube numbers after legitimate vs. illegitimate cross-pollination did not reveal any difference, suggesting that D. verticillatus possesses CSI unrelated to heteromorphic self- and intramorph-incompatibility found in other heterostylous members of the Lythraceae. CSI resulting from differential pollen tube growth may minimize geitonogamous selfing when cross pollen is abundant, while maximizing fecundity when cross pollen is scarce due to local clonal spread.

A guide to noninvasive intermittent ventilatory support

Patients who use home-based medical technologies, such as noninvasive intermittent ventilatory support, may require hospitalization on units where the staff is unfamiliar with this type of equipment. Consequently, acute care clinicians need resources so they can provide safe care to these patients. This article provides background information about noninvasive intermittent ventilatory support, presents a case study to illustrate key aspects of each type of support, and provides quick reference tables to assist acute care clinicians in managing this technology.