Comportamiento epidemiológico del VIH en Paraguay, 2017 / Epidemiological behavior of HIV in Paraguay, 2017

RESUMEN Introducción: El VIH no es solo un problema de salud pública, puesto que una vez generalizada, la epidemia tiene consecuencias de largo alcance para todos los sectores sociales y para el desarrollo mismo. Puede diezmar a la fuerza laboral, crear grandes cantidades de huérfanos, exacerbar la pobreza y la desigualdad, y ejercer una tremenda presión sobre los servicios sociales y de salud. Objetivo: Describir el comportamiento epidemiológico del VIH en Paraguay durante los meses de enero a diciembre del 2017. Material y Métodos: Estudio observacional, descriptivo de corte transversal, sobre los pacientes con VIH captados por el PRONASIDAdurante los meses de enero a diciembre del 2017. El análisis se realizó con STATA v.14.0, los datos se expresan en medidas de tendencia central y dispersión, y tabla de proporciones. Resultados: Fueron ingresados durante el 2017, 1443 casos reportados, de los cuales el 71,03% (102) fueron del sexo masculino, el 61,95% (894) fue de Asunción. La vía de transmisión fue 98,82% (1426) fue la sexual. El 35,22% (392) fueron caso de SIDA y el 3,53% (51) fallecieron durante el 2017. Conclusión: La epidemia sigue siendo concentrada en grupos de riesgo, con predominancia del sexo masculino, las características dé la población estudiada muestra que la mayoría son procedentes del Asunción y Central, la vía sexual continúa siendo la más frecuente vía de transmisión, en vista a lo anterior es importante implementar políticas y estrategias para mejorar la captación de pacientes, asimismo aumentar la promoción de la educación sexual en grupos de riesgos. Palabras clave: VIH; Sida; Paraguay; Grupos de Riesgo.

Introduction: HIV is not only a public health problem, because once it is widespread, the epidemic has farreaching consequences for all social sectors and for development itself. It can decimate the workforce, create large numbers of orphans, exacerbate poverty and inequality, and exert tremendous pressure on social and health services. Objective: To describe the epidemiological behavior of HIV in Paraguay during the months of January to December 2017. Material and Methods: An observational, crosssectional, descriptive study on HIV patients recruited by PRONASIDAduring the months of January to December 2017. The analysis was performed with STATA v.14.0; the data are expressed in measures of central tendency and dispersion, and proportions table. Results: 1443 reported cases were admitted during 2017, of which 71.03% (102) were male, 61.95% (894) were from Asuncion. The transmission route was 98.82% (1426) was sexual. 35.22% (392) were cases of AIDS and 3.53% (51) died during 2017. Conclusion: The epidemic continues to be concentrated in risk groups, with predominance of males, the characteristics of the studied population shows that the majority are from Asuncion and Central, the sexual route continues to be the most frequent route of transmission, in view of The foregoing is important to implement policies and strategies to improve the uptake of patients, also increase the promotion of sex education in risk groups. Keywords: HIV; AIDS; Paraguay; Risk Groups

Prevalencia de lesiones precursoras de cáncer de cuello uterino y antecedentes sexuales/reproductivos de indígenas de Caaguazú, Paraguay 2015-2017 / Prevalence of precursor lesions of cervical cancer and sexual/reproductive antecedents of natives of Caaguazú, Paraguay 2015-2017

Introducción: El cáncer de cuello uterino es una de las patologías más graves en la vida de las mujeres. Causó 266 000 muertes en mujeres por esta patología en el año 2012, un 85% en los países de ingresos bajos y medianos. Objetivo: Determinar la prevalencia de lesiones precursoras de cáncer de cuello uterino y antecedentes sexuales/reproductivos de indígenas de Caaguazú durante los años 2015 a 2017. Materiales y métodos: Se realizó un estudio observacional, descriptivo, de corte transversal con muestreo no probabilístico. Se estudió a indígenas que se encuentran registrados en el Programa de Patología Cervical. Los datos obtenidos se ingresaron en Microsoft Excel© 2016, para el análisis se utilizó STATA® 14.0. Los resultados fueron presentados en tablas y gráficos. Resultados: Ingresaron en el estudio 129 indígenas con una edad media de 26±10 años. La prevalencia de lesiones precursoras de cáncer de cuello uterino fue de 13,18%. Las lesiones más frecuentemente encontradas en orden de frecuencia fueron ASCUS 10,08%; CIN I 2,32%; CIN II 0,77%; no se observó CIN III, ni carcinoma in situ. Las edades en las que se presentaron con mayor frecuencia fueron entre 25 a 44 años en un 70,59%. El 58,8% de las que presentaron lesiones cervicales tuvo menarca< 12 años; 76,5% relaciones sexuales < 15 años y el 82,35 % son gran multíparas. Conclusión: La prevalencia de lesiones precursoras de cáncer de cuello uterino es similar a estudios de otros países y menor a algunos estudios que se realizaron en Paraguay en población no indígena. Se encontró mayor porcentaje de lesiones en las edades medias, menarca temprana, inicio precoz de vida sexual y en multíparas. Palabras clave: Lesión intraepitelial cervical; cáncer de cérvix; citología; Paraguay; Servicios de Salud del Indígena.

Introduction: Cervical cancer is one of the most serious pathologies in the life of women. It caused 266 000 deaths in women due to this pathology in 2012, 85% in low and middle income countries. Objective: To determine the prevalence of precursor lesions of cervical cancer and sexual/reproductive antecedents of natives of Caaguazú during the years 2015 to 2017. Materials and methods: An observational, descriptive, cross-sectional study with non-probabilistic sampling was carried out. Indigenous people registered in the Cervical Pathology Program were studied. The data obtained were entered in Microsoft Excel © 2016, STATA® 14.0 was used for the analysis. The results were presented in tables and graphs. Results: The study included 129 indigenous people with an average age of 26 ± 10 years. The prevalence of precursor lesions of cervical cancer was 13.18%. The most frequently found lesions in order of frequency were ASCUS 10.08%; CIN I 2.32%; CIN II 0.77%; no CIN III was observed, nor carcinoma in situ. The ages in which they occurred most frequently were between 25 and 44 years in 70.59%. 58.8% of those who presented cervical lesions had menarche <12 years; 76.5% sexual intercourse <15 years and 82.35% are large multiparous. Conclusion: The prevalence of precursor lesions of cervical cancer is similar to studies from other countries and less than some studies that were conducted in Paraguay in a non-indigenous population. A higher percentage of lesions was found in the middle ages, early menarche, and early onset of sexual life and in multiparous women. Keywords: Cervical intraepithelial lesion; cervical cancer; cytology; Paraguay; Indigenous Health Services.

Multidirectional lip-closing force in adults with mandibular deviation.

The purpose of this study was to investigate the relationship between multidi-rectional lip-closing force and facial soft tissue morphology in adults with mandibular deviation. Fifteen Japanese adults with mandibular deviation participated in this study. The deviation value was defined as the horizontal distance between soft tissue menton and the facial midline. The side of the soft tissue menton relative to the facial midline was defined as the deviated side and the opposite side as the non-deviated side. The signals of directional lip-closing force (DLCF) were investigated in 8 directions. Total lip-closing force (TLCF) was calculated by adding DLCFs in 8 directions. Correlations and differences between the variables were analysed statistically. Significant positive correlations between TLCF and DLCFs were determined in six directions with the exception of the horizontal direction. Significant positive correlations for seven pairs of opposing DLCFs were found. The lower non-deviated DLCF was smaller than the three pairs of opposing lip-closing forces. Negative significant correlation was found between the deviation value and the upper deviated DLCF (P < 0·05). In individuals with mandibular deviation, lip-closing force in the lower non-deviated direction was found to be smaller than the opposing lip-closing forces. When mandibular deviation was greater, the upper deviated lip-closing force was smaller.

Hydrogen sulfide-induced colonic mucosal cytoprotection involves T-type calcium channel-dependent neuronal excitation in rats.

Hydrogen sulfide (H(2)S) is generated from L-cysteine by certain enzymes including cystathionine-γ-lyase (CSE) and cystathionine-ß-synthase (CBS), and causes excitation of nociceptors mainly via activation of Ca(v)3.2 T-type Ca(2+) channels in the peripheral tissue, facilitating somatic and colonic pain. Here, we investigated whether sensory nerves and Ca(v)3.2 are involved in the H(2)S-induced mucosal cytoprotection against 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. Colitis was evaluated 3 days after intracolonic (i.c.) TNBS in the rat. Phosphorylation of ERK in the spinal dorsal horn was detected by immunohistochemistry. Protein expression of Ca(v)3.2 in the dorsal root ganglia (DRG) and of CSE and CBS in the colon was determined by Western blotting. Repeated i.c. NaHS significantly suppressed the TNBS-induced colitis in rats, an effect prevented by ablation of sensory nerves with repeated administration of capsaicin. Repeated pretreatment with T-type Ca(2+) channel blockers including ethosuximide significantly reduced the protective effects of repeated i.c. NaHS in the rats with TNBS-induced colitis. A single i.c. administration of NaHS induced ethosuximide-sensitive prompt phosphorylation of ERK in the spinal dorsal horn at T13 and L6-S1 levesl in the rats 1 day or 3 days after TNBS treatment, but not in naive rats. Ca(v)3.2 protein was upregulated in DRG 1 day after i.c. TNBS in rats, while CSE, but not CBS, protein was downregulated in the colon. Our findings suggest that luminal H(2)S causes excitation of sensory nerves most probably by activating Ca(v)3.2 T-type Ca(2+) channels that are upregulated in the early stage of colitis, leading to colonic mucosal cytoprotection in rats.

Biological activity of Helicobacter pylori components in mammalian cells: is it independent of proteinase-activated receptors?

To clarify the relationship between Helicobacter pylori (H. pylori), a risk factor for gastritis, peptic ulcer and gastric cancer, and proteinase-activated receptors (PARs) that contribute to inflammatory responses, we determined and characterized the biological activity of H. pylori components in the mammalian cells that express PARs. The activity of H. pylori extracts was assessed in distinct cell lines with high expression of PAR1 (RGM1 cells), PAR2 (A549 cells), or PAR2 and PAR4 (HCT-15 cells). A PAR1-activating peptide (AP), but not H. pylori extracts, caused prostaglandin E2 (PGE2) release in RGM1 cells. On the other hand, H. pylori extracts produced release of PGE2 and interleukin-8 (IL-8) in A549 and HCT-15 cells, respectively, as a PAR2-AP did. The activity of H. pylori extracts in A549 cells was not affected by a proteinase inhibitor or exposure to boiling, but abolished by inhibitors of lipopolysaccharide (LPS), IRAK-1/4 or NF-κB. The activity of H. pylori extracts in HCT-15 cells was partially suppressed by boiling or the proteinase inhibitor. In rat platelets that express PAR4 and PAR3, like a PAR4-AP, H. pylori extracts induced aggregation when assessed in platelet rich plasma, an effect unaffected by the proteinase inhibitor, but did not cause aggregation of washed rat platelets that responded to the PAR4-AP or thrombin. The present study thus shows the biological activities of H. pylori extracts in A549 and HCT-15 cells or rat platelets, and suggests that they are not mediated by any PAR-activating proteinases, but may involve the other pathogenic factors including LPS.

Inhibition of T-type calcium channels and hydrogen sulfide-forming enzyme reverses paclitaxel-evoked neuropathic hyperalgesia in rats.

Hydrogen sulfide (H2S), a gasotransmitter, facilitates pain sensation by targeting Ca(v)3.2 T-type calcium channels. The H2S/Ca(v)3.2 pathway appears to play a role in the maintenance of surgically evoked neuropathic pain. Given evidence that chemotherapy-induced neuropathic pain is blocked by ethosuximide, known to block T-type calcium channels, we examined if more selective T-type calcium channel blockers and also inhibitors of cystathionine-γ-lyase (CSE), a major H2S-forming enzyme in the peripheral tissue, are capable of reversing the neuropathic pain evoked by paclitaxel, an anti-cancer drug. It was first demonstrated that T-type calcium channel blockers, NNC 55-0396, known to inhibit Ca(v)3.1, and mibefradil inhibited T-type currents in Ca(v)3.2-transfected HEK293 cells. Repeated systemic administration of paclitaxel caused delayed development of mechanical hyperalgesia, which was reversed by single intraplantar administration of NNC 55-0396 or mibefradil, and by silencing of Ca(v)3.2 by antisense oligodeoxynucleotides. Systemic administration of dl-propargylglycine and ß-cyanoalanine, irreversible and reversible inhibitors of CSE, respectively, also abolished the established neuropathic hyperalgesia. In the paclitaxel-treated rats, upregulation of Ca(v)3.2 and CSE at protein levels was not detected in the dorsal root ganglia (DRG), spinal cord or peripheral tissues including the hindpaws, whereas H(2)S content in hindpaw tissues was significantly elevated. Together, our study demonstrates the effectiveness of NNC 55-0396 in inhibiting Ca(v)3.2, and then suggests that paclitaxel-evoked neuropathic pain might involve the enhanced activity of T-type calcium channels and/or CSE in rats, but not upregulation of Ca(v)3.2 and CSE at protein levels, differing from the previous evidence for the neuropathic pain model induced by spinal nerve cutting in which Ca(v)3.2 was dramatically upregulated in DRG.

Chelating luminal zinc mimics hydrogen sulfide-evoked colonic pain in mice: possible involvement of T-type calcium channels.

Luminal hydrogen sulfide (H(2)S) causes colonic pain and referred hyperalgesia in mice through activation of T-type Ca(2+) channels. To test a hypothesis that H(2)S might chelate and remove endogenous Zn(2+) that inhibits the Ca(v)3.2 isoform of T-type Ca(2+) channels, facilitating visceral nociception, we asked if intracolonic (i.col.) administration of Zn(2+) chelators mimics H(2)S-induced visceral nociception. Visceral nociceptive behavior and referred abdominal allodynia/hyperalgesia were determined after i.col. administration of NaHS, a donor for H(2)S, or Zn(2+) chelators in mice. Phospholylation of extracellular signal-regulated protein kinase (ERK) in the spinal cord was analyzed by immunohistochemistry. The visceral nociceptive behavior and referred abdominal allodynia/hyperalgesia caused by i.col. NaHS in mice were abolished by i.col. preadministration of zinc chloride (ZnCl(2)), known to selectively inhibit Ca(v)3.2, but not Ca(v)3.1 or Ca(v)3.3, isoforms of T-type Ca(2+) channels, and by i.p. preadministration of mibefradil, a pan-T-type Ca(2+) channel blocker. Two distinct Zn(2+) chelators, N,N,N',N'-tetrakis(2-pyridylmethyl)ehylenediamine (TPEN) and dipicolinic acid, when administered i.col., mimicked the NaHS-evoked visceral nociceptive behavior and referred abdominal allodynia/hyperalgesia, which were inhibited by mibefradil and by NNC 55-0396, another T-type Ca(2+) channel blocker. Like i.col. NaHS, i.col. TPEN caused prompt phosphorylation of ERK in the spinal dorsal horn, an effect blocked by mibefradil. Removal of luminal Zn(2+) by H(2)S and other Zn(2+) chelators thus produces colonic pain through activation of T-type Ca(2+) channels, most probably of the Ca(v)3.2 isoform. Hence, endogenous Zn(2+) is considered to play a critical role in modulating visceral pain.

A comparative study of the modified Sauvé-Kapandji procedure for rheumatoid wrist with and without stabilization of the proximal ulnar stump.

We compared the clinical and radiological results of the modified Sauvé-Kapandji procedure for 41 of 86 operated rheumatoid wrists with (n=22) and without (n=19) stabilization of the proximal ulnar stump with a slip of half the extensor carpi ulnaris tendon. Gender, age, and follow-up period were similar in the two groups. We found no difference clinically or on radiographs between the two groups other than better early postoperative pain relief in those stabilized. Stabilization of the proximal ulnar stump may not be necessary in the modified Sauvé-Kapandji procedure for rheumatoid wrists.

Novel antagonists for proteinase-activated receptor 2: inhibition of cellular and vascular responses in vitro and in vivo.

BACKGROUND AND PURPOSE: Proteinase-activated receptor 2 (PAR(2)) is a G-protein coupled receptor associated with many pathophysiological functions. To date, the development of PAR(2) antagonists has been limited. Here, we identify a number of novel peptide-mimetic PAR(2) antagonists and demonstrate inhibitory effects on PAR(2)-mediated intracellular signalling pathways and vascular responses. EXPERIMENTAL APPROACH: The peptide-mimetic compound library based on the structures of PAR(2) agonist peptides were screened for inhibition of PAR(2)-induced calcium mobilisation in human keratinocytes. Representative compounds were further evaluated by radioligand binding and inhibition of NFkappaB transcriptional activity and IL-8 production. The vascular effects of the antagonists were assessed using in vitro and in vivo models. KEY RESULTS: Two compounds, K-12940 and K-14585, significantly reduced SLIGKV-induced Ca(2+) mobilisation in primary human keratinocytes. Both K-12940 and K-14585 exhibited competitive inhibition for the binding of a high-affinity radiolabelled PAR(2)-ligand, [(3)H]-2-furoyl-LIGRL-NH(2), to human PAR(2) with K(i) values of 1.94 and 0.627 microM respectively. NFkappaB reporter activity and IL-8 production were also significantly reduced. Furthermore, relaxation of rat-isolated aorta induced by SLIGRL-NH(2) was inhibited competitively by K-14585. K-14585 also significantly lowered plasma extravasation in the dorsal skin of guinea pigs and reduced salivation in mice. CONCLUSIONS AND IMPLICATIONS: K-12940 and K-14585 antagonized PAR(2) competitively, resulting in inhibition of PAR(2)-mediated signalling and physiological responses both in vitro and in vivo. These peptide-mimetic PAR(2) antagonists could be useful in evaluating PAR(2)-mediated biological events and might lead to a new generation of therapeutically useful antagonists.

Hydrogen sulfide as a novel mediator for pancreatic pain in rodents.

OBJECTIVE: Hydrogen sulfide (H(2)S) is formed from l-cysteine by multiple enzymes including cystathionine-gamma-lyase (CSE) in mammals, and plays various roles in health and disease. Recently, a pronociceptive role for H(2)S in the processing of somatic pain was identified. Here, the involvement of H(2)S in pancreatic pain is examined. METHODS: Anaesthetised rats or mice received an injection of NaHS, a donor for H(2)S, or capsaicin into the pancreatic duct, and the expression of spinal Fos protein was detected by immunohistochemistry. Pancreatitis was created by 6 hourly doses of caerulein in unanaesthetised mice, and pancreatitis-related allodynia/hyperalgesia was evaluated using von Frey hairs. CSE activity and protein levels in pancreatic tissues were measured using the colorimetric method and western blotting, respectively. RESULTS: Either NaHS or capsaicin induced the expression of Fos protein in the superficial layers of the T8 and T9 spinal dorsal horn of rats or mice. The induction of Fos by NaHS but not capsaicin was abolished by mibefradil, a T-type Ca(2+) channel blocker. In conscious mice, repeated doses of caerulein produced pancreatitis accompanied by abdominal allodynia/hyperalgesia. Pretreatment with an inhibitor of CSE prevented the allodynia/hyperalgesia, but not the pancreatitis. A single dose of mibefradil reversed the established pancreatitis-related allodynia/hyperalgesia. Either the activity or protein expression of pancreatic CSE increased after the development of caerulein-induced pancreatitis in mice. CONCLUSIONS: The data suggest that pancreatic NaHS/H(2)S most probably targets T-type Ca(2+) channels, leading to nociception, and that endogenous H(2)S produced by CSE and possibly T-type Ca(2+) channels are involved in pancreatitis-related pain.

Luminal hydrogen sulfide plays a pronociceptive role in mouse colon.

OBJECTIVE: Given recent evidence that hydrogen sulfide (H(2)S), a gasotransmitter, promotes somatic pain through redox modulation of T-type Ca(2+) channels, the roles of colonic luminal H(2)S in visceral nociceptive processing in mice were examined. METHODS: After intracolonic administration of NaHS, an H(2)S donor, visceral pain-like behaviour and referred abdominal allodynia/hyperalgesia were evaluated. Phosphorylation of extracellular signal-regulated protein kinase (ERK) in the spinal dorsal horn was determined immunohistochemically. The whole-cell recording technique was used to evaluate T-type Ca(2+) currents (T-currents) in cultured dorsal root ganglion (DRG) neurons. RESULTS: Like capsaicin, NaHS, administered intracolonically at 0.5-5 nmol per mouse, triggered visceral nociceptive behaviour accompanied by referred allodynia/hyperalgesia in mice. Phosphorylation of ERK in the spinal dorsal horn was detected following intracolonic NaHS or capsaicin. The behavioural effects of intracolonic NaHS were abolished by a T-type channel blocker or an oxidant, but not inhibitors of L-type Ca(2+) channels or ATP-sensitive K(+) (K(ATP)) channels. Intraperitoneal NaHS at 60 micromol/kg facilitated intracolonic capsaicin-evoked visceral nociception, an effect abolished by the T-type channel blocker, although it alone produced no behavioural effect. In DRG neurons, T-currents were enhanced by NaHS. CONCLUSIONS: These findings suggest that colonic luminal H(2)S/NaHS plays pronociceptive roles, and imply that the underlying mechanisms might involve sensitisation/activation of T-type channels probably in the primary afferents, aside from the issue of the selectivity of mibefradil.

Selective growth of vertically aligned double- and single-walled carbon nanotubes on a substrate at 590 °C.

Vertically aligned double- and single-walled carbon nanotubes (DWNTs and SWNTs) were synthesized on a substrate at 590 °C by hot-filament chemical vapor deposition. An optimized combination of iron and aluminum layers as the catalyst resulted in iron particles ranging from 1-5 nm floating in an aluminum matrix after annealing. Selective synthesis of DWNTs and SWNTs from such particles was achieved by adjusting the dilution ratio of acetylene that was used as the source gas. The yield of DWNTs among all CNTs was as high as 81%, while that of SWNTs was almost 100%. The diameter distribution of DWNTs was narrow, with a standard deviation of about 12%.

Gastrointestinal roles for proteinase-activated receptors in health and disease.

It has been almost a decade since the molecular cloning of all four members of the proteinase-activated receptor (PAR) family was completed. This unique family of G protein-coupled receptors (GPCRs) mediates specific cellular actions of various endogenous proteinases including thrombin, trypsin, tryptase, etc. and also certain exogenous enzymes. Increasing evidence has been clarifying the emerging roles played by PARs in health and disease. PARs, particularly PAR1 and PAR2, are distributed throughout the gastrointestinal (GI) tract, modulating various GI functions. One of the most important GI functions of PARs is regulation of exocrine secretion in the salivary glands, pancreas and GI mucosal epithelium. PARs also modulate motility of GI smooth muscle, involving multiple mechanisms. PAR2 appears to play dual roles in pancreatitis and related pain, being pro-inflammatory/pro-nociceptive and anti-inflammatory/anti-nociceptive. Similarly, dual roles for PAR1 and PAR2 have been demonstrated in mucosal inflammation/damage throughout the GI tract. There is also fundamental and clinical evidence for involvement of PAR2 in colonic pain. PARs are thus considered key molecules in regulation of GI functions and targets for development of drugs for treatment of various GI diseases.

Dual modulation of the tension of isolated gastric artery and gastric mucosal circulation by hydrogen sulfide in rats.

To clarify roles of H2S in regulation of gastric circulation, we investigated effects of NaHS, a H2S donor, on tension of isolated rat gastric artery and gastric mucosal blood flow in rats. In the precontracted ring preparations, NaHS caused contraction and relaxation at low and high concentrations, respectively. The NaHS-induced vasorelaxation was only partially blocked by glibenclamide, a K+ (ATP) channel inhibitor. The contractile activity of NaHS disappeared by removal of the endothelium or by inhibition of nitric oxide synthase and the endothelium-derived hyperpolarizing factor (EDHF) pathways. Intravenous injection of NaHS caused transient increase followed by decrease in gastric mucosal blood flow in rats. Collectively, in the gastric artery, NaHS appears to cause relaxation through both K+ (ATP) channel-dependent and -independent pathways and contraction through inhibition of NO and EDHF pathways. Together with the in vivo results, our study implies that H2S plays multiple complex roles in regulation of gastric circulation.

Monophasic epithelial synovial sarcoma arising in the temporomandibular joint.

Synovial sarcoma is a mesenchymal spindle-cell tumour that occurs infrequently in the head and neck. It originates from unknown stem cells differentiating into mesenchymal and/or epithelial structures. Most synovial sarcomas are biphasic in character, consisting of epithelial and spindle-cell elements. Here is reported a case of monophasic epithelial synovial sarcoma arising in the temporomandibular joint. The tumour was of a predominantly epithelial pattern, although a minute area of sarcomatous cells was found. The primary mode of treatment was wide en-bloc excision. Two years after surgery, the patient died of hepatocellular carcinoma, but there was no evidence of synovial sarcoma recurrence.

Proteinase-activated receptors in the gastrointestinal system: a functional linkage to prostanoids.

Proteinase-activated receptors (PARs), G protein-coupled receptors, play critical roles in the alimentary system. Increasing evidence suggests that endogenous prostaglandins (PGs) mediate some of PARs' gastrointestinal functions. Systemic administration of the PAR1 agonist protects against gastric mucosal injury through PG formation in rats. PGs also appear to contribute, at least in part, to enhancement of gastric mucosal blood flow and suppression of gastric acid secretion by PAR1 activation. There is also evidence for involvement of PGs in modulation of gastrointestinal motility by PAR1 or PAR2. Importantly, modulation of ion transport by PAR1 or PAR2 in the intestinal mucosal epithelium is largely mediated by PGs. Studies using gastric and intestinal mucosal epithelial cell lines imply that the PAR1-triggered formation of PGs involves multiple signaling pathways including Src, EGF receptor trans-activation and activation of MAP kinases. Collectively, a functional linkage of PAR1 and/or PAR2 to PGs is considered important in the gastrointestinal system.

Stability of canine distemper virus (CDV) after 20 passages in Vero-DST cells expressing the receptor protein for CDV.

Isolates 007Lm, S124C and Ac96I and a Vero cell-adapted Onderstepoort strain of canine distemper viruses (CDV) were examined for stability after passages in Vero cells expressing the canine signaling lymphocyte activation molecule (dogSLAM, the intrinsic receptor to CDV). These viruses passage once in Vero cells expressing dogSLAM (Vero-DST) cells (original) and after 20 passages (20p) were compared by using sequence analyses and growth characteristics. All four strains of 20p grew well and were slightly better than their originals. The 20p viruses developed a cytopathic effect slightly lower than the original strains. A few changes in amino acids in the H gene were between the 20p and the original viruses, but the sites of changes were not specific. Fragments of P, M and L genes of all strains showed no nucleotide changes after the passages. These results showed that: (1) passages of CDVs in Vero-DST cells induced amino acid changes only in the H gene, not in the P, M and L genes, unlike in a previous study with Vero cells; (2) passages did not markedly affect the growth characteristics of every viral strain. These results indicate that Vero cells expressing canine SLAM allow the isolation and passaging of CDV without major changes in viral genes.

In vivo evidence that protease-activated receptors 1 and 2 modulate gastrointestinal transit in the mouse.

1. Protease-activated receptors (PARs) 1 and 2 modulate the gastric and intestinal smooth muscle motility in vitro. In the present study, we examined if activation of PAR-2 and PAR-1 could alter gastrointestinal transit in mice. 2. Intraperitoneal administration of the PAR-2-activating peptide SLIGRL-NH(2), but not the inactive control LSIGRL-NH(2), at 1 - 5 micromol kg(-1), in combination with the aminopeptidase inhibitor amastatin at 2.5 micromol kg(-1), facilitated gastrointestinal transit in a dose-dependent manner. The human PAR-1-derived peptide SFLLR-NH(2) and the specific PAR-1 agonist TFLLR-NH(2), but not the inactive control FSLLR-NH(2), at 2.5 - 10 micromol kg(-1), in combination with amastatin, also promoted gastrointestinal transit. 3. The Ca2+-activated, small conductance K+ channel inhibitor apamin at 0.01 micromol kg(-1) significantly potentiated the actions of SLIGRL-NH(2) and TFLLR-NH(2) at subeffective doses. 4. The increased gastrointestinal transit exerted by either SLIGRL-NH(2) at 5 micromol kg(-1) or TFLLR-NH(2) at 10 micromol kg(-1) was completely abolished by the L-type Ca2+ channel inhibitor verapamil at 61.6 micromol kg(-1). In contrast, the tyrosine kinase inhibitor genistein at 18.5 micromol kg(-1) failed to modify the effects of the agonists for PAR-2 or PAR-1. 5. These findings demonstrate that PAR-1 and PAR-2 modulate gastrointestinal transit in mice in vivo. Our data also suggest that the PAR-1-and PAR-2-mediated effects are modulated by apamin-sensitive K+ channels and are dependent on activation of L-type Ca2+ channels, but independent of tyrosine kinase. Our study thus provides novel evidence for the physiological and/or pathophysiological roles of PARs 1 and 2 in the digestive systems, most probably during inflammation.

Lipopolysaccharide-induced subsensitivity of protease-activated receptor-2 in the mouse salivary glands in vivo.

Protease-activated receptor-2 (PAR-2) acts as a modulator of multiple physiological/pathophysiological functions including salivary exocrine secretion. Given the supersensitivity of endothelial PAR-2 under endotoxaemia, we investigated if endotoxin/lipopolysaccharide (LPS) could alter the sensitivity of PAR-2 in the salivary glands. The in vivo salivation in response to i.v. administration of the PAR-2-activating peptide SLIGRL-NH2, but not of carbachol, gradually decreased 6-20 h after LPS administration in the mice. The LPS-induced hyporeactivity to the PAR-2 agonist was partially reversed by repeated administration of aprotinin, a non-specific protease inhibitor. PAR-2 mRNA levels in the salivary glands, as assessed by the semi-quantitative RT-PCR analysis, remained unchanged following LPS challenge. Our findings indicate that in contrast to the supersensitivity of endothelial PAR-2 as described previously, subsensitivity of PAR-2 in the salivary glands develops during the LPS-induced systemic inflammation, which might involve desensitisation of PAR-2 by endogenous proteases.