Nosocomial outbreak of extended-spectrum beta-lactamase-producing Salmonella isangi in pediatric wards

Since May 2000, extended-spectrum beta-lactamase-producing (ESBL) Salmonella Isangi were isolated from pediatric patients at a tertiary hospital. A total of 41 patients with positive cultures were reviewed, and the majority presented with gastroenteritis, fever, or both. One ESBL phenotype was noted in all isolates, and clonality was confirmed by pulsed-field gel electrophoresis. This is the first report of Salmonella sp. ESBL resistance in our hospital.

Differential roles of amygdaloid nuclei in the anxiolytic- and antidepressant-like effects of the V1b receptor antagonist, SSR149415, in rats

RATIONALE

SSR149415 ((2S, 4R)-1-[5-chloro-1-[(2,4-dimethoxyphenyl)sulfonyl]-3-(2-methoxyphenyl)-2-oxo-2,3-dihydro-1H-indol-3-yl]-4-hydroxy-N,N-dimethyl-2-pyrrolidinecarboxamide), the first selective nonpeptide vasopressin V1b receptor antagonist has been shown to induce antidepressant-and anxiolytic-like effects following systemic administration, whereas intraseptal infusion of the drug engender antidepressant-but not anxiolytic-like effects.

OBJECTIVES

Based on recent evidence that V1b receptors are located within the amygdaloid complex, a structure which is well known for its modulatory role of emotional processes, the possible involvement of the different amygdaloid nuclei in the anxiolytic- and/or antidepressant-like effects of SSR149415 was examined.

METHODS

Male Sprague-Dawley or Wistar rats were infused with SSR149415 into the central (CeA), the basolateral (BlA), or the medial (MeA) nucleus of the amygdala and tested 10 min after microinjection in the elevated plus-maze or the forced-swimming test, two models typically used for assessing the anxiolytic and antidepressant effects of drugs, respectively.

RESULTS

Microinjection of SSR149415 into the BlA (1-10 ng), but not into the CeA or the MeA, increased the percentage of time spent in the open arms of the elevated plus-maze, indicating anxiolytic-like effects. Furthermore, in the forced-swimming test, microinjection of the drug into the CeA (1, 10, and 100 ng), BlA (1-10 ng), or MeA (100 ng) decreased immobility, an effect which is indicative of an antidepressant-like action. Together, these findings indicate that while the antidepressant-like effects of SSR149415 are mediated by different amygdaloid nuclei, its anxiolytic-like effects appear to involve only the basolateral nucleus of the amygdala. Moreover, these results add further evidence to the role of extrahypothalamic vasopressinergic systems in the control of emotional responses.

Selective blockade of NK2 or NK3 receptors produces anxiolytic- and antidepressant-like effects in gerbils

There is a growing interest in the potential anxiolytic- and antidepressant-like effects of compounds that target neurokinin receptors. Since the structure and the pharmacology of the human neurokinin receptor resembles that of gerbils, rather than that of mice or rats, we decided to investigate the anxiolytic- and /or antidepressant-like effects of NK1 (SSR240600), NK2 (saredutant) and NK3 (osanetant) receptor antagonists in gerbils. It was found that saredutant (3-10 mg/kg, p.o.) and osanetant (3-10 mg/kg, p.o.) produced anxiolytic-like effects in the gerbil social interaction test. These effects were similar to those obtained with the V1b receptor antagonist SSR149415 (3-10 mg/kg, p.o.), diazepam (1 mg/kg, p.o.) and buspirone (10 mg/kg, p.o.). Fluoxetine and SSR240600 were devoid of effects in this test. In the tonic immobility test in gerbils, saredutant (5-10 mg/kg, i.p.) and osanetant (5-10 mg/kg, i.p.) produced similar effects to those observed with fluoxetine (7.5-15 mg/kg, i.p.), SSR149415 (10-30 mg/kg, p.o.) and buspirone (3 mg/kg, i.p.). Diazepam and SSR240600 were inactive in this paradigm. In conclusion, the present study indicates further that NK2 and NK3 receptor antagonists may have therapeutic potential in the clinical management of anxiety and depression.

Comparison of atazanavir with lopinavir/ritonavir in patients with prior protease inhibitor failure: a randomized multinational trial

OBJECTIVES

To compare change from baseline in HIV RNA and fasting low-density lipoprotein (LDL) cholesterol levels in protease inhibitor (PI)-experienced patients receiving unboosted atazanavir 400 mg once daily versus lopinavir 400 mg boosted with ritonavir 100 mg twice daily, with two nucleoside reverse transcriptase inhibitors (NRTIs). Secondary objectives included virologic response, CD4 cell count changes, other lipid changes, safety, and tolerability.

METHODS

Randomized, open-label, multinational, 48-week study in patients with one PI-regimen failure, HIV RNA > or = 1000 copies/mL, and CD4 count > or = 50 cells/mm3.

RESULTS

Three hundred patients were randomized; 290 treated (144 atazanavir, 146 lopinavir/ritonavir). Lopinavir/ritonavir resulted in a significantly greater reduction in HIV RNA than unboosted atazanavir (-2.02 vs -1.59 log10 copies/mL, p < 0.001) at week 48. Secondary efficacy endpoints also favored lopinavir/ritonavir; the differences in efficacy between regimens were also observed in secondary analyses comparing those subjects who were susceptible and those subjects who were resistant to their respective PIs at baseline. However, both regimens were equally effective in subjects who had no baseline NRTI mutations. From baseline to week 48, atazanavir resulted in either no change or decreases in fasting LDL cholesterol, total cholesterol, and fasting triglycerides (-6%, -2%, and +1%), whereas lopinavir/ritonavir resulted in increases (+3%, +12%, and +53%) (p < 0.05, all between-treatment comparisons). Fewer patients were administered lipid-lowering therapy in the atazanavir arm (6% vs 20% for lopinavir/ritonavir). Both regimens were safe and well tolerated.

CONCLUSIONS

While both treatments demonstrated good antiviral efficacy, relatively greater antiviral suppression was observed with lopinavir/ritonavir. In those patients with no NRTI mutations at baseline, both regimens demonstrated comparable virologic suppression. Atazanavir-treated patients demonstrated a superior lipid profile and required less frequent lipid-lowering treatment.

Associations of ambient illumination with mood: contribution of ophthalmic dysfunctions

Evidence suggests that ocular pathology could reduce light-stimulated neuronal signaling to the suprachiasmatic nuclei. This study investigated associations of ambient illumination with moods, while considering the contribution of ophthalmic dysfunctions. Seventy Black (59%) and White (41%) Americans participated in the study. Their average age was 68.27+/-5.97 years; 73% were women. Baseline data included: physical health, mood, and sociodemographics. Ophthalmic factors including visual acuity, visual field defects, intraocular pressure, vertical and horizontal cup-to-disk ratios, and nerve-fiber-layer thickness were assessed at SUNY Downstate's eye clinic. The following week, participants wore the Actiwatch-L at home to monitor ambient illumination and sleep. Cosine analyses were performed on the logarithm of measured illumination, yielding the mesor and acrophase of daily illumination exposure. Sleep was estimated with an automatic scoring algorithm. Of the sample, 25% reported visual impairment and 85% reported good to excellent health; 27% were visually impaired according to American criteria. Partial correlation analyses showed an inverse correlation of daily illumination levels to depressed mood [r(p)=-0.33, P<0.05], when age, sex, ethnicity, income, BMI, diabetes, hypertension, respiratory disease, and habitual sleep duration were controlled. With further control for ophthalmic factors, the magnitude and significance of the correlation diminished [r(p)=-0.26, NS]. Individuals receiving daily illumination later in the day reported more depressed moods [r(p)=0.36, P<0.01]; of note, this correlation was not significant after control for the covariates [r(p)=0.18, NS]. Regression analysis indicated that the ophthalmic factors explained 13% of the variance in depression. Our results show that both the level and timing of ambient illumination are associated with mood. Furthermore, they suggest that visual impairment has a mediating effect on the associations of ambient illumination with depression, supporting the notion that ocular pathology lessens the efficacy of daily illumination in promoting positive moods.

Comparison of the Antinociceptive Profiles of Gabapentin and 3-Methylgabapentin in Rat Models of Acute and Persistent Pain: Implications for Mechanism of Action

The anticonvulsant gabapentin (GBP) has been shown effective for the treatment of neuropathic pain, although its mechanism of action remains unclear. A recent report has suggested that binding to the alpha(2)delta subunit of voltage-gated calcium channels contributes to its antinociceptive effect, based on the stereoselective efficacy of two analogs: (1S,3R)3-methylgabapentin (3-MeGBP) (IC(50) = 42 nM), which is effective in neuropathic pain models; and (1R,3R)3-MeGBP (IC(50) > 10,000 nM), which is ineffective (Field et al., 2000). The present study was designed to further examine the profiles of GBP and 3-MeGBP in rat models of acute and persistent pain. Systemic administration of GBP or (1S,3R)3-MeGBP inhibited tactile allodynia in the spinal nerve ligation model of neuropathic pain, whereas (1R,3R)3-MeGBP was ineffective. The antiallodynic effect of GBP, but not (1S,3R)3-MeGBP, was blocked by i.t. injection of the GABA(B) receptor antagonist [3-[[(3,4-dichlorophenyl)methyl]amino]propyl](diethoxymethyl)phosphinic acid (CGP52432). Systemic GBP or (1S,3R)3-MeGBP also inhibited the second phase of formalin-evoked nociceptive behaviors, whereas (1R,3R)3-MeGBP was ineffective. However, both (1S,3R)3-MeGBP and (1R,3R)3-MeGBP, but not GBP, inhibited first phase behaviors. In the carrageenan model of inflammatory pain, systemic GBP or (1R,3R)3-MeGBP failed to inhibit thermal hyperalgesia, whereas (1S,3R)3-MeGBP had a significant, albeit transient, effect. Systemic (1S,3R)3-MeGBP, but not GBP or (1R,3R)3-MeGBP, also produced an antinociceptive effect in the warm water tail withdrawal test of acute pain. These data demonstrate that GBP and 3-MeGBP display different antinociceptive profiles, suggesting dissimilar mechanisms of antinociceptive action. Thus, the stereoselective efficacy of 3-MeGBP, presumably related to alpha(2)delta binding, likely does not completely account for the mechanism of action of GBP.

High-resolution sequence-based DPA1 typing identified two novel DPA1 alleles, DPA1*010303 and DPA1*0303, from a Kenyan population

We report here two novel DPA1 alleles, DPA1*010303 and DPA1*0303, identified from a Kenyan population during sequence-based HLA-DPA1 typing. Molecular cloning and sequencing of multiple clones confirmed that one of the new DPA1 alleles is identical to DPA1*010301 at exon 2, except for a single nucleotide substitution (ACG ACC) at codon 15. The new allele has been named by the WHO Nomenclature Committee as DPA1*010303. The second novel DPA1 allele is identical to DPA1*0301, except for a single nucleotide difference (GAA GAC) at codon 28 that changed the amino acid from Glu to Asp. The new allele has been named by the WHO Nomenclature Committee as DPA1*0303. Identification of the two novel DPA1 alleles reflects the genetic diversity of this East African population.

Introduction: Is viral shedding a surrogate marker for transmission of genital herpes?

Genital herpes, caused by either herpes simplex virus type 1 or 2 (HSV-1 and HSV-2), is a significant public health problem worldwide. It increases the risk of infection with HIV, upregulates HIV after infection and can be associated with serious morbidity and mortality. It is now known that clinical and subclinical viral reactivation with resultant shedding from anogenital mucosa occurs frequently, resulting in transmission during sexual contact. Sexual transmission of HSV infection is common, even between monogamous individuals. Antiviral therapy reduces the frequency and degree of viral shedding and lowers the transmission rate in discordant monogamous couples, although transmission can still occur in people prescribed antiviral therapy. These encouraging data raise important questions for the management of genital HSV infection, particularly with regard to the prevention of transmission. Although the quantity of virus present is clearly important in transmission of some viruses, it is not clear whether this is the case for HSV transmission. Ideally, a surrogate marker needs to be able to identify individuals with detectable amounts of virus, and differentiate them from individuals with detectable amounts of virus that are transmissible. The aim of this supplement is to explore the issues surrounding the validation of surrogate markers of transmission of HSV, using examples from other human viral diseases, and to review the available evidence. In the future, exploration of these issues may shed light on management and prevention strategies. In particular, the results may clarify what evidence is required to warrant prescribing a drug for reducing HSV transmission, and for which patient populations this strategy is appropriate.

HSV shedding

Viral shedding of HSV occurs frequently in infected individuals. HSV is shed asymptomatically from multiple anatomical sites and shedding, like exposure, is a significant risk for transmission. However, the relationship between shedding frequency, viral titer and transmission is unknown. HSV-2 shedding is affected by the site and time since acquisition of infection. The advent of sensitive PCR techniques has shown that the magnitude and frequency of viral shedding is higher than shown previously with viral culture techniques. It has also clearly demonstrated that suppressive (daily) antiviral therapy reduces clinical and subclinical reactivation rates, and has been successfully used in the prevention of recurrent oral and genital HSV infections. A recent study has demonstrated that daily antiviral therapy with valaciclovir can significantly reduce transmission of HSV-2 between discordant heterosexual couples in monogamous relationships.

HSV-2 transmission

A number of important risk factors for the acquisition of HSV-2 have been established including female gender, black or Hispanic ethnic origin, HIV infection, age, and increased number of sexual partners. Transmission is influenced by a number of biological factors such as sexual behavior, use of condoms, duration of relationships, and knowledge of a partner's serologic status. Vertical transmission (transmission of HSV from mother to neonate) is potentially life-threatening; neonatal HSV infection is associated with significant morbidity and mortality. The valaciclovir transmission study provides evidence that an antiviral agent can interrupt the transmission of a viral sexually transmitted disease between serologically discordant sexual partners. This review explores the importance of the cofactors that affect transmission, and makes recommendations on considerations for the prophylactic use of antiviral agents for the prevention of transmission in other patient populations.

Prevalence of BSE in cattle found dead, euthanased or emergency slaughtered on farms in western France in 2000, 2001 and 2002

The overall trend and the trend within birth cohorts of the prevalence of bovine spongiform encephalopathy (BSE) in cattle found dead, euthanased or emergency slaughtered on farms in the Bretagne, Basse Normandie and Pays de la Loire regions of France, during the periods from August 7 to December 22 in 2000, 2001 and 2002, were analysed by non-conditional logistic regression, adjusted for the region and for the type of animals. The overall prevalence of BSE during these three periods decreased from 2.71 per 1000 in 2000 to 1.41 per 1000 in 2001 and 0.42 per 1000 in 2002. The prevalence within birth cohorts started to decrease for the cohort born between July 1, 1995 and June 30, 1996 (cohort 95/96) and the trend was reinforced for cohort 96/97, suggesting that the exposure of animals to the BSE agent had started to decrease for animals born after July 1995, that is, one year before the ban on specified risk materials in meat and bone meal was implemented in France. However, considering that most of the animals would have been infected at between six and 18 months of age, the decrease may have been due, at least partly, to this control measure.

Lessons from HIV and hepatitis viruses

Surrogate markers are an important component in the process of investigating management and prevention strategies, and for increasing understanding of viral diseases. The importance of surrogate markers and applied statistical models is particularly true for HIV. For HIV infection, the development of such methods provides new approaches for evaluation of HIV therapies and vaccines, and for the study of HIV transmission and its pathogenesis. The complex natural history of hepatitis B infection demonstrates that viral load is not the only predictor of transmission of this virus; for hepatitis C infection, viral load per se is not a prognostic factor for disease progression, but cumulative viral load may affect the outcome, and therapy is aimed at eliminating active viral replication.

Endocrine tumors of the duodenum. A study of 55 cases relative to clinicopathological features and hormone content

BACKGROUND/AIMS

Study of prognosis of duodenal endocrine tumors.

METHODOLOGY

Retrospective study concerned 55 duodenal endocrine tumors discovered in biopsy or surgical specimens. Follow-up records available for 49 patients indicated that inconspicuous associated clinical manifestations were often found subsequently. Seven patients were classified as Zollinger-Ellison syndrome and seven as multiple endocrine neoplasia (6 MEN I and 1 MEN II).

RESULTS

Tumors were small (mean 1.28cm) and located preferentially in the first and second part of the duodenum. Fifty-four were well-differentiated and one poorly differentiated. Immunochemistry revealed 30 G-cell tumors (54.6%), 15 D-cell (27.3%), two plurihormonal (EC cell and G cell), and one GRH-cell, whereas seven could not be classified. Fifteen patients died (five in relation to their disease). Twenty-one had metastases (liver, nodes, lung), eight of whom are still alive.

CONCLUSIONS

Eighty-eight percent of duodenal endocrine tumors were gastrinomas, small plurifocal tumors and somatostatinomas preferentially located in the ampullar region and diagnosed because of hematemesis or icterus. Size is an important prognostic factor in determining whether surgery is required. The prognosis is better for D- and G-cell tumors than pancreatic endocrine tumors. Duodenal endocrine tumors in multiple endocrine neoplasia have a good prognosis, but can be associated with pancreatic plurihormonal tumors and metastases.

Interleukin-6 production and secretion by human parathyroids

Parathyroid hormone (PTH) stimulates osteoblasts to produce the proinflammatory cytokine interleukin-6 (IL-6), causing bone resorption. In patients with primary hyperparathyroidism, elevated serum levels of IL-6 normalize after resection of parathyroid tumours. Because IL-6 is also expressed in normal parathyroids and in other endocrine cells (adrenal and islet), we hypothesized that parathyroid tumours might contribute directly to the elevated serum IL-6 levels in patients with hyperparathyroidism. Immunohistochemistry identified IL-6, PTH, and chromogranin-A (an endocrine and neuroendocrine tumour marker) in normal, adenomatous and hyperplastic parathyroids. Using immunofluorescence and confocal microscopy, IL-6 co-localized with PTH and with chromogranin-A in parathyroid cells. All cultured parathyroid tumours secreted IL-6 at levels markedly higher than optimally stimulated peripheral blood mononuclear cells. Supernates from cultured parathyroids stimulated proliferation of an IL-6-dependent cell line, and anti-IL-6 MoAb abolished this stimulatory effect. IL-6 mRNA was documented in cultured parathyroid tumours, cultured normal parathyroids, fresh operative parathyroid tumours and fresh operative normal specimens. In conclusion, these data show that parathyroid tumours and normal parathyroids contain, produce and secrete IL-6. Our findings present a novel pathway by which human parathyroids may contribute markedly to IL-6 production and elevation of serum IL-6 levels in patients with hyperparathyroidism. The physiological relevance of IL-6 production by human parathyroids remains to be determined, but IL-6 secretion by parathyroid tumours may contribute to bone loss and to other multi-system complaints observed in these patients.

HIV Lipodystrophy Case Definition using Artificial Neural Network Modelling

Objective

A case definition of HIV lipodystrophy has recently been developed from a combination of clinical, metabolic and imaging/body composition variables using logistic regression methods. We aimed to evaluate whether artificial neural networks could improve the diagnostic accuracy.

Methods

The database of the case-control Lipodystrophy Case Definition Study was split into 504 subjects (265 with and 239 without lipodystrophy) used for training and 284 independent subjects (152 with and 132 without lipodystrophy) used for validation. Back-propagation neural networks with one or two middle layers were trained and validated. Results were compared against logistic regression models using the same information.

Results

Neural networks using clinical variables only (41 items) achieved consistently superior performance than logistic regression in terms of specificity, overall accuracy and area under the ROC curve. Their average sensitivity and specificity were 72.4 and 71.2%, as compared with 73.0 and 62.9% for logistic regression, respectively (area under the ROC curve, 0.784 vs 0.748). The discriminating performance of the neural networks was largely unaffected when built excluding 13 parameters that patients may not have readily available. The average sensitivity and specificity of the neural networks remained the same when metabolic variables were also considered (total 60 items) without a clear advantage against logistic regression (overall accuracy 71.8%). The performance of networks considering also body composition variables was similar to that of logistic regression (overall accuracy 78.5% for both).

Conclusions

Neural networks may offer a means to improve the discriminating performance for HIV lipodystrophy, when only clinical data are available and a rapid approximate diagnostic decision is needed. In this context, information on metabolic parameters is apparently not helpful in improving the diagnosis of HIV lipodystrophy, unless imaging and body composition studies are also obtained.

SSR591813, a novel selective and partial alpha4beta2 nicotinic receptor agonist with potential as an aid to smoking cessation

(5aS,8S,10aR)-5a,6,9,10-Tetrahydro,7H,11H-8,10a-methanopyrido[2',3':5,6]pyrano[2,3-d]azepine (SSR591813) is a novel compound that binds with high affinity to the rat and human alpha4beta2 nicotinic acetylcholine receptor (nAChR) subtypes (Ki = 107 and 36 nM, respectively) and displays selectivity for the alpha4beta2 nAChR (Ki, human alpha3beta4 > 1000, alpha3beta2 = 116; alpha1beta1deltagamma > 6000 nM and rat alpha7 > 6000 nM). Electrophysiological experiments indicate that SSR591813 is a partial agonist at the human alpha4beta2 nAChR subtype (EC50 = 1.3 micro M, IA =19% compared with the full agonist 1,1-dimethyl-4-phenyl-piperazinium). In vivo findings from microdialysis and drug discrimination studies confirm the partial intrinsic activity of SSR591813. The drug increases dopamine release in the nucleus accumbens shell (30 mg/kg i.p.) and generalizes to nicotine or amphetamine (10-20 mg/kg i.p.) in rats, with an efficacy approximately 2-fold lower than that of nicotine. Pretreatment with SSR591813 (10 mg/kg i.p.) reduces the dopamine-releasing and discriminative effects of nicotine. SSR591813 shows activity in animal models of nicotine dependence at doses devoid of unwanted side effects typically observed with nicotine (hypothermia and cardiovascular effects). The compound (10 mg/kg i.p.) also prevents withdrawal signs precipitated by mecamylamine in nicotine-dependent rats and partially blocks the discriminative cue of an acute precipitated withdrawal. SSR591813 (20 mg/kg i.p.) reduces i.v. nicotine self-administration and antagonizes nicotine-induced behavioral sensitization in rats. The present results confirm important role for alpha4beta2 nAChRs in mediating nicotine dependence and suggest that SSR591813, a partial agonist at this particular nAChR subtype, may have therapeutic potential in the clinical management of smoking cessation.

Does the density of lymphatic vascular space invasion affect the prognosis of stage Ib and IIA node negative carcinoma of the cervix?

Lymphatic vascular space invasion (LVSI) has been noted as a poor prognostic factor in many tumors. In some studies of carcinoma of the cervix, LVSI has been demonstrated to be independent of other prognostic factors. The aim of this study is to evaluate if, by a simple quantitative technique, the density of lymphatic invasion could be correlated with the risk of recurrence in node negative early stage carcinoma of the cervix. We analyzed the pathology and clinical course of 71 consecutive patients with stage IB and IIA carcinoma of the cervix treated primarily by radical hysterectomy and pelvic lymphadenectomy. All cases had negative nodes and adequate surgical margins. There were 67 patients suitable for evaluation. Tumour type, grade, stage and the dimensions of the tumor were recorded. The density of LVSI was categorized as absent (45%), mild (15%), moderate (33%) or severe (7%) depending on the number of lymphatic vascular spaces involved per high power field in the worst affected slide. The patients were followed for 2-8(1/2) years with a mean follow up of 4 years and 2 months. There were 13 recurrences and 7 deaths. All recurrences occurred in less than 2 years after surgery. The risk of recurrence was 40% for patients with extensive LVSI, 32% for moderate, 30% for mild and 3% if LVSI was absent. Only the presence of LVSI was associated with an increased risk of recurrence. The density of lymphatic invasion as represented by the number of lymphatic spaces occupied on the worst histological slide offered no further clinically useful information.