Immunohistochemical study of RhoC GTPase in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a disease with high mortality and morbidity. Metastasis is a significant prognostic factor of the OSCC patients. The Rho GTPases are signaling proteins that controls important cellular processes in various complex mechanisms involved in carcinogenesis. This study aimed to evaluate the expression pattern of RhoC in OSCC protein by immunohistochemistry in situ. Immunohistochemical reactions were performed for RhoC by the method of avitina-biotin-peroxidase activity in samples OSCC: well differentiated (BD, n=6), moderately differentiated (MD, n=24) and poorly differentiated (PD, n=13). The morphometry was taken by QuickScore (percentage and intensity of staining) and only intensity staining. There was no statistical difference (p>0.05) through none of the modes of morphometric analysis between BD, MD and PD. And the RhoC staining was not associated with the histopathologic grading (χ2 = 4.65, p>0.05). However, the morphological evaluation of immunostained for RhoC in cases BD, MD, PD OSCC, regardless of histopathologic grading. These results suggest that there is no correlation between the RhoC immunoexpression and histopathological grading of OSCC.

Anoxia-inducible endonuclease activity as a potential basis of the genomic instability of cancer cells.

Normal rat fibroblasts exhibit a staged response to anoxia which in several respects parallels processes activated in malignant tumor cells. We describe here a new element of the anoxic response, the induction by anoxia of a sequestered endonuclease activity. Such activity is elevated approximately 3-fold within anoxic fibroblasts and during Hirt DNA isolation is able to digest chromatin to produce a nucleosomal ladder. However, DNA is not measurably affected within intact cells, and cells retain complete viability as the endonuclease is induced. The anoxia-inducible endonuclease acts without specificity for DNA sequence. Trace leakage of this endonuclease into the nucleus has obvious potential to underlie the known propensity of anoxic cells to undergo amplification and may be associated with the break-related genomic instability of cancer cells.

Steroid receptors in epithelial ovarian carcinoma: relation to clinical parameters and survival.

Estrogen receptor (ER) and progestin receptor were measured in samples of tumors obtained at first laparotomy from 97 previously untreated patients suffering with a primary ovarian epithelial tumor, for whom a 3-year follow-up was available. The presence or absence of steroid receptors (threshold arbitrarily fixed at 10 fmol/mg of cytoplasmic protein) was determined by the dextran coated charcoal method and related to a number of patient characteristics such as the residual disease (cutoff, 2 cm), histological type, International Federation of Gynecologists and Obstetricians grade and stage, and age. Results were analyzed by univariate and multivariate methods. (a) The tumor ER positivity was associated with better survival; progestin receptor showed a similar trend but did not reach statistical significance. (b) After stratification for residual tumor the association ER positivity/better survival was still statistically significant in the subset of patients with residual tumor greater than 2 cm. (c) When the median survival times were considered it became apparent that progestin receptor absence nullified the effect associated with positive ER. (d) Multivariate analysis confirmed that among the variables considered the main determinants of prognosis were the size of the residual tumor, serous histological type, and positive ER.

Integration of biocontrol agents and food-grade additives for enhancing protection of stored apples from Penicillium expansum.

Forty-nine compounds currently used as additives in foods were tested in combination with three biocontrol agents, the yeasts Rhodotorula glutinis, Cryptococcus laurentii, and the yeastlike fungus Aureobasidium pullulans, to increase their antagonistic activity against Penicillium expansum, the causal agent of blue mold on apples. Twelve additives dramatically improved the antagonistic activity of one or more of the tested biocontrol agents. In a two-way factorial experiment with these selected additives the percentage of P. expansum rots on apples was significantly influenced by the antagonist and the additive as well as by their interaction. The combination of the biocontrol agents and some additives resulted in a significantly higher activity with respect to the single treatments applied separately, producing additive or synergistic effects. Some of the selected additives combined with a low yeast concentration (106 cells per ml) had comparable or higher efficacy than the biocontrol agents applied alone at a 100-fold higher concentration (10(8) cells per ml). Some organic and inorganic calcium salts, natural gums, and some antioxidants displayed the best results. In general, the effect of each additive was specific to the biocontrol isolate used in the experiments. Possible mechanisms involved in the activity of these beneficial additives and their potential application in effective formulations of postharvest biofungicides are discussed.

ras oncogene-induced transformation of a rat seminal vesicle epithelial cell line produces a marked increase of adenylate cyclase and protein kinase C activities.

Cells transformed by Kirsten murine sarcoma virus (Ki-MSV) have basal adenylate cyclase activity (AC) higher than control cells and comparable level of forskolin-stimulated AC activity. Moreover, a higher protein kinase C (PKC) activity was found to be present in the transformed cells. The molecular mechanism underlying the increase of AC activity was investigated. Our findings strongly suggest that this biochemical event is due to a marked decrease of the alpha i negative control of the enzyme, even though the alpha i of transformed cells appears to possess fully functional domains interacting with both the effector enzyme and the agonist-activated receptor.

Latex allergy: a review for the dental professional.

Reactions to latex products are reportedly occurring with an increased frequency both in patients and in health care providers. Natural rubber latex is found in numerous products, and adverse latex reactions range from contact dermatitis to life-threatening anaphylaxis. A complete understanding of the pathophysiology of latex allergy provides the foundation for the proper diagnosis and treatment of patients with latex allergy. This article provides the reader with a review of latex allergy and suggests strategies for the management of patients with latex hypersensitivity.

[The incidence of hepatitis B markers in pregnant women at their first consultation in metropolitan-area health centers, São Paulo, Brazil]. / Frequência de marcadores de hepatite B em gestantes de primeira consulta em centros de saúde de área metropolitana, São Paulo, Brazil.

Hepatitis B is a severe disease when acquired during the neonatal period. The identification of the infected pregnant women allows prevention of newborn infection by active and passive immunization soon after birth. We studied pregnant women in their first visit to eight different primary medical centers in Butantan, a subdistrict of S. Paulo city. 477 samples were tested for anti-HBc. From 44 (9.2%) anti-HBc positive samples, 2 (0.4%) were HBsAg positive and 37 (7.7%) were anti-HBs positive. A risk factor for hepatitis B could only be detected in 8 (18.9%) of the 44 anti-HBc positive samples.

Detection of hepatitis A antibodies by ELISA using saliva as clinical samples.

The possibility of detecting acute infection and immunity using body fluids that are easier to collect than blood, mainly in children, would facilitate the investigation and follow-up of outbreaks of hepatitis A (HAV). Our study was carried out to evaluate the detection of anti-HAV IgM, IgA and total antibodies in saliva using serum samples as reference. Forty three paired serum and saliva samples were analyzed. From this total, 24 samples were obtained from children and 1 from one adult during the course of acute hepatitis A; an additional 18 samples were obtained from health professionals from Adolfo Lutz Institute. The sensitivity to detect anti-HAV IgM was 100% (95%CI: 79.1 to 100.0%), employing saliva as clinical samples. In detecting anti-HAV IgA, the sensitivity was 80. 8% (95%CI: 60.0 to 92.7%) and for the total antibodies was 82.1% (95%CI: 62.4 to 93.2%). The specificity was 100% for each. The rate of agreement was high comparing the results of serum and saliva samples for detecting HAV antibodies. We conclude that saliva is an acceptable alternative specimen for diagnosing acute hepatitis A infection, and for screening individuals to receive hepatitis A vaccine or immunoglobulin.

Histidine degradation enzymes in rat liver: induction by high protein intake.

High protein dietary content stimulates urea formation in ureotelic animals but does not exert almost any effect on ammonia production from L-amino acids in vitro. L-histidine and L-threonine are the only amino acids which are most actively deaminated by ureotelic animals fed on a high protein diet. All the steps of L-histidine metabolism have been studied: it has been found that both the histidine transaminase pathway and the histidase pathway are stimulated. Glutamic acid is also a product of histidine catabolism through the histidase pathway, but its catabolism is unaffected by the dietary protein content. These data suggest the existence of independent mechanism controlling the catabolism of the two amino acids.

Low insulin concentrations stimulate in vitro the soluble guanylate cyclase activity of rat liver.

The soluble guanylate cyclase activity of rat liver appears to be stimulated in VITRO by insulin at pMolar concentrations, while proinsulin, denaturated insulin or desoctapeptide insulin, are not able to stimulate the studied enzymic activity. Corresponding concentrations of other peptide hormones such as corticotropin (ACTH) or glucagon, either in the absence or in the presence of bacitracin, do not show any effect on the investigated enzymic system. Insulin stimulation of the soluble guanylate cyclase is characterized by a significant increase in the Vmax together with a decrease of the apparent Km. Insulin at low concentrations doesn't affect the cyclic GMP hydrolyzing activity; conversely higher concentrations of the hormone, while exerting a less marked effect on the guanylate cyclase activity, inhibit the cyclic GMP hydrolyzing activity.

A survey of resident selection procedures in oral and maxillofacial surgery.

PURPOSE: This study was conducted to analyze the current procedures used in oral and maxillofacial surgery resident selection, to compare these selection procedures with those used 2 decades ago, to determine whether any differences exist in the selection procedures between 4-year certificate programs and programs that offer formal medical education, and to provide criteria to assist in the counseling of dental students on the application process for oral and maxillofacial surgery residencies. SUBJECTS AND METHODS: Questionnaires were sent to the 106 oral and maxillofacial surgery graduate training programs accredited by the American Dental Association. To provide for a more direct comparison to the study completed in 1976, the current questionnaire was developed, using the original survey as a model. It was divided into 5 sections: general information, information obtained from the formal application and letters of recommendation, the interview, the decision process, and a retrospective view of past decisions. The results were tabulated and the Pearson chi-square test was used to determine statistical significance when comparing the 4-year certificate programs to the programs that offer formal medical education. RESULTS: Seventy-one responses (75.5%) from nonmilitary programs were returned and analyzed. Thirty-nine responses represented dual-degree (MD) programs. Factors that were considered very important when judging a candidate's written application included dental school class rank (76.1%), dental school basic science grades (70.4%), and dental school clinical grades (63.4%). Dual-degree programs placed a greater emphasis on predental basic science grades (P < .01) and dental national board scores (P < .05). When asked about prior resident selection, 86.7% of the respondents said they would select 80% of their former residents again. In addition, 89.9% of the respondents were satisfied with their current selection process. CONCLUSIONS: The procedures used to select oral and maxillofacial surgery residents are relatively constant among programs. Although the dual-degree and 4-year certificate programs use the same criteria for resident selection, the dual-degree programs place greater emphasis on predental academic performance and on the results of the national dental boards. Criteria used 22 years ago to select residents are still applicable, but there has been a shift in the importance of some variables.

GTPase and transglutaminase are associated in the secretion of the rat anterior prostate.

We have found that in the secretion of rat anterior prostate, a hydrolyzing activity on GTP is present with a high affinity for the substrate; ATP, GDP, and ADP are not substrates for enzymatic activity. At the same time we have shown that GTP is a negative modulator for the well-known type IV transglutaminase activity present in the prostatic secretion. The hydrolyzing activity on GTP appears to be due to two molecular species: a high-molecular-weight GTPase, having electrophoretical mobility higher than 100 kDa, and a low-molecular-weight GTPase, of about 30 kDa. The two enzymatic activities are associated in the prostatic secretion with the transglutaminase (type IV). We describe an experimental procedure to separate them.

Expression of the hepatitis B virus surface antigen in mammalian cells using an Epstein-barr-virus-derived vector.

The hepatitis B virus surface antigen (HBsAg) gene, under control of the inducible mouse metallothionein I gene promoter, was inserted in an expression vector based on the Epstein-Barr virus (EBV). This vector was introduced into human cells by DNA transfection and clones were selected for their resistance to hygromycin B. The recombinant EBV vector replicates efficiently as an episome in human cells and approximately six copies per cell were found in one clone of hygromycin-B-resistant cells. These cells produce high levels of HBsAg in the presence of metals. The protein is mainly found in the cell medium, suggesting that the HBsAg is secreted from the cells.

Role of calcium in chloride secretion mediated by cAMP pathway activation in rabbit distal colon mucosa.

Effects of Ca2+ on adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion were investigated in intact mucosa and isolated crypt cells of rabbit descending colon. Addition of 10 microM prostaglandin (PG)E2 or forskolin to tissues incubated in Ca(2+)-free medium increased the size of short-circuit current (Isc) and Cl- secretion as estimated by unidirectional 36Cl flux measurements (net flux = -2.31 +/- 0.24 vs. -1.22 +/- 0.10 mueq.h-1.cm-2, n = 4, P < 0.001). Addition of 10 microM PGE2 to tissues incubated in 1.2 mM Ca2+ Ringer induced a 7-fold increase in mean cAMP level, whereas it produced an 11-fold increase in tissues exposed to Ca(2+)-free medium. Membrane preparations from whole mucosa incubated in Ca(2+)-free medium displayed a cyclic nucleotide phosphodiesterase activity significantly lower than controls (18.76 +/- 0.54 vs. 31.20 +/- 0.39 pmol cAMP. mg protein-1.min-1, means +/- SE, n = 4, P < 0.001). Ca2+ removal also affected adenylate cyclase (AC) responsiveness to agonists; AC activity increased in controls by 54 and 226% after stimulation with 10 microM PGE2 and forskolin, respectively, but it increased more (77 and 325%, respectively) after incubation in Ca(2+)-free solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis E virus immunoglobulin G antibodies in different populations in Campinas, Brazil.

The seroprevalence of anti-hepatitis E virus (HEV) antibodies was investigated by enzyme immunoassay in 205 volunteer blood donors, 214 women who attended a center for anonymous testing for human immunodeficiency virus (HIV) infection, and 170 hospital employees in Campinas, a city in southeastern Brazil. The prevalence of anti-HEV antibodies ranged from 2.6% (3 of 117) in health care professionals to 17.7% (38 of 214) in women who considered themselves at risk for HIV. The prevalence of anti-HEV antibodies in health care professionals was not significantly different from that in healthy blood donors (3.0%, 5 of 165) and blood donors with raised alanine aminotransferase levels (7.5%, 3 of 40). The prevalence of anti-HEV antibodies (13.2%, 7 of 53) in cleaning service workers at a University hospital was similar to that among women at risk for HIV infection. These results suggest that HEV is circulating in southeastern Brazil and that low socioeconomic status is an important risk factor for HEV infection in this region.