[Identification of new conserved and variable regions in the 16S rRNA gene of acetic acid bacteria and acetobacteraceae family]

The Acetobacteraceae family of the class Alpha Proteobacteria is comprised of high sugar and acid tolerant bacteria. The Acetic Acid Bacteria are the economically most significant group of this family because of its association with food products like vinegar, wine etc. Acetobacteraceae are often hard to culture in laboratory conditions and they also maintain very low abundances in their natural habitats. Thus identification of the organisms in such environments is greatly dependent on modern tools of molecular biology which require a thorough knowledge of specific conserved gene sequences that may act as primers and or probes. Moreover unconserved domains in genes also become markers for differentiating closely related genera. In bacteria, the 16S rRNA gene is an ideal candidate for such conserved and variable domains. In order to study the conserved and variable domains of the 16S rRNA gene of Acetic Acid Bacteria and the Acetobacteraceae family, sequences from publicly available databases were aligned and compared. Near complete sequences of the gene were also obtained from Kombucha tea biofilm, a known Acetobacteraceae family habitat, in order to corroborate the domains obtained from the alignment studies. The study indicated that the degree of conservation in the gene is significantly higher among the Acetic Acid Bacteria than the whole Acetobacteraceae family. Moreover it was also observed that the previously described hypervariable regions V1, V3, V5, V6 and V7 were more or less conserved in the family and the spans of the variable regions are quite distinct as well.

Information space receding horizon control

In this paper, we present a receding horizon solution to the optimal sensor scheduling problem. The optimal sensor scheduling problem can be posed as a partially observed Markov decision problem whose solution is given by an information space (I-space) dynamic programming (DP) problem. We present a simulation-based stochastic optimization technique that, combined with a receding horizon approach, obviates the need to solve the computationally intractable I-space DP problem. The technique is tested on a sensor scheduling problem, in which a sensor must choose among the measurements of N dynamical systems in a manner that maximizes information regarding the aggregate system over an infinite horizon. While simple, such problems nonetheless lead to very high dimensional DP problems to which the receding horizon approach is well suited.

Superficial angiomyxoma of the external ear not associated with Carney's complex: a case report

Superficial angiomyxomas are rare tumours and multiple tumours occurring in the external ear are invariably associated with Carney's complex. In the present study, a solitary superficial angiomyxoma was found in a 20 year old lady; and there was no evidence of any of the components of Carney's complex at the time of presentation or at the end of 2 years of follow-up, after the surgical excision of the tumour.

An epidemiological study on patients undergoing dacryocystorhinostomy

Dacryocystorhinostomy is performed in patients with naso-lacrimal duct obstruction to bypass the site of obstruction so as to relieve the patient of the irritating and socially embarrassing symptoms of epiphora. We discuss the various epidemiological aspects especially the vast difference by which the females out-number the males in patients undergoing DCR and the likely explanations for this difference in our study on 74 patients which underwent DCR in our institute.

Slide session, British Society for Haematology, 45th Annual Scientific Meeting, Manchester, 2005

Each year at the Annual Scientific Meeting of the British Society for Haematology, there is a slide session in which microscopic slides of six patients with haematological disorders are discussed by two experts. Further data and the final diagnosis are then provided. The slide session is presented here, as it occurred at the meeting.

Randomized, double-blind, placebo-controlled, short-term trial of ropinirole in restless legs syndrome

BACKGROUND AND PURPOSE

Restless legs syndrome (RLS) is a condition characterized by an urge to move the legs, usually accompanied by lower limb paresthesias. These symptoms worsen at rest, are relieved by activity, and are worse at night. Previous studies have suggested that dopaminergic drugs such as L-dopa and dopamine agonists, as well as benzodiazepines and opioids, can treat RLS successfully. The purpose of this study was to test the clinical efficacy of ropinirole, a D2/D3 agonist, in the treatment of RLS in a double-blind, short-term, placebo-controlled clinical trial.

PATIENTS AND METHODS

After undergoing successful open-label titration and dose adjustments with ropinirole for RLS symptoms over a period of 4 weeks, 22 RLS patients (mean age=50.8; mean duration of symptoms=26.1 years) were randomized to receive either placebo (n=13) or ropinirole (n=9) for 2 additional weeks. Outcome measures included assessment of periodic leg movements in sleep (PLMS) recorded with nocturnal polysomnography and RLS symptoms as assessed with the International Restless Legs Syndrome Study Group (IRLSSG) Rating Scale. Secondary outcomes included sleep macroarchitecture.

RESULTS

Results indicated that relative to placebo, ropinirole, at a mean dose of 1.4mg HS significantly decreased PLMS and RLS symptoms. Sleep macroarchitecture did not change. Side effects were typical of all dopamine agonists and were dose related. The majority of patients elected to continue treatment with ropinirole upon study completion.

CONCLUSIONS

Ropinirole successfully treated long-standing RLS and can be considered a viable short-term treatment for this condition.

Novel use of guanidinium isothiocyanate in the isolation of Mycobacterium tuberculosis DNA from clinical material

Nucleic acid amplification technologies offer great promise for the rapid, sensitive and specific diagnosis of tuberculosis. However, the isolation of inhibitor-free DNA from biological specimens is a bottleneck of the PCR assay. Here we describe a simple method for the isolation of PCR-amplifiable DNA of Mycobacterium tuberculosis from all types of samples of pulmonary and extrapulmonary origin tested. Briefly, it involves concentration of the bacilli by high-speed centrifugation, removal of PCR inhibitors by a wash solution containing guanidinium isothiocyanate and the release of bacterial DNA by heating in the presence of detergents and Chelex-100 resin. The entire process is accomplished within approximately 3 h. The method has been validated on 780 samples of human, bovine and guinea pig origin including sputum, cerebrospinal fluid, pulmonary fluids, pus, fine needle aspirate, tissue, blood and milk.

Diversity and coverage of structural sublibraries selected using the SAGE and SCA algorithms

It is often impractical to synthesize and test all compounds in a large exhaustive chemical library. Herein, we discuss rational approaches to selecting representative subsets of virtual libraries that help direct experimental synthetic efforts for diverse library design. We compare the performance of two stochastic sampling algorithms, Simulating Annealing Guided Evaluation (SAGE; Zheng, W.; Cho, S. J.; Waller, C. L.; Tropsha, A. J. Chem. Inf. Comput. Sci. 1999, 39, 738-746.) and Stochastic Cluster Analysis (SCA; Reynolds, C. H.; Druker, R.; Pfahler, L. B. Lead Discovery Using Stochastic Cluster Analysis (SCA): A New Method for Clustering Structurally Similar Compounds J. Chem. Inf. Comput. Sci. 1998, 38, 305-312.) for their ability to select both diverse and representative subsets of the entire chemical library space. The SAGE and SCA algorithms were compared using u- and s-optimal metrics as an independent assessment of diversity and coverage. This comparison showed that both algorithms were capable of generating sublibraries in descriptor space that are diverse and give reasonable coverage (i.e. are representative) of the original full library. Tests were carried out using simulated two-dimensional data sets and a 27 000 compound proprietary structural library as represented by computed Molconn-Z descriptors. One of the key observations from this work is that the algorithmically simple SCA method is capable of selecting subsets that are comparable to the more computationally intensive SAGE method.

Clinical and sensorimotor gating effects of ketamine in normals

The clinical similarities between PCP psychosis and schizophrenia have contributed importantly to the development of the glutamate hypothesis of schizophrenia. Sensory gating, as measured by prepulse inhibition of the acoustic startle reflex (PPI), is impaired in patients with schizophrenia. In animals, the noncompetitive NMDA antagonists PCP and ketamine disrupt PPI in a way that resembles the defect seen in schizophrenia. The purpose of this work is to investigate the modulation of sensory gating in humans by subanaesthetic doses of ketamine. 16 healthy male subjects received a 60-min infusion of ketamine (0.5 mg/kg) or normal saline on two separate days in a randomized double-blind crossover design. Clinical ratings and PPI were done during the infusion on both days. Ketamine produced robust clinical effects. Dissociative symptoms as measured by the CADSS increased from 0 +/- 0.0 to 29.3 +/- 14.3; negative symptoms (Affect Rating Scale) increased from 17.2 +/- 0.8 to 24.8 +/- 3.1; and total BPRS scores increased from 18.3 +/- 0.8 to 26.4 +/- 5.1. ANOVAs for these ratings were all significant at the p <.000 level, although BPRS increases were not in the range seen in decompensated schizophrenic patients. The amplitudes of the startle responses to pulse-alone stimuli were not significantly different on ketamine and placebo days. Ketamine did not cause disruption in PPI as expected. On the contrary, in the first block of the PPI session ketamine significantly enhanced PPI (ANOVA; F=6.15, p =.026). These results indicate that the clinical effects of ketamine are not coupled with schizophrenic-like disruption of PPI in normal controls.

Effects of smoking on acoustic startle and prepulse inhibition in humans

RATIONALE

Prepulse inhibition of the acoustic startle response (PPI) is a paradigm in which a startle response to an auditory stimulus is reduced when that stimulus is preceded by a lower intensity, non-startling stimulus (prepulse). PPI is used as an operational measure of sensorimotor gating in both humans and other mammals. Acute administration of nicotine enhances PPI in rats, an effect that has been recently demonstrated in humans.

OBJECTIVES

We compared PPI in 12 male smokers and 14 male non-smokers tested in four repeat startle sessions across 2 test days in order to examine further the effects of smoking and smoking withdrawal on acoustic startle and PPI.

METHODS

In a crossover design, the smokers smoked ad lib or abstained from smoking overnight prior to 9 a.m. testing. These 2 test days were in randomized order. On both days, smokers were immediately retested after smoking three cigarettes. Non-smokers were tested twice on each of 2 separate days.

RESULTS

Across sessions, the smokers had reduced startle to pulse alone stimuli in the first block of each session when compared to the non-smokers. The non-smokers had no change in gating across their four test sessions. For the smokers, the abstinence condition produced a non-significant reduction in PPI compared to that of the ad lib smoking day. During the smoking abstinence session, smokers had comparable gating to non-smokers. Smoking immediately after washout produced a significant improvement in PPI such that gating in the smokers exceeded that of the non-smokers.

CONCLUSION

Smoking after overnight washout from cigarettes enhanced sensorimotor gating compared to pre-smoking values and compared to gating in non-smokers.

Host-mediated juvenoids affect development and metamorphosis of endoparasitic wasp, Chelonus blackburni (Hymenoptera: Braconidae) and consequent morphogenetic derangements in its reproductive system

Juvenoids, applied topically on larvae of Corcyra cephalonica harbouring the larvae of the parasitoid, produce various types of developmental derangements in parasitoid C. blackburni. The deformed morphs, e.g., apparently normal adults, adultoids and prolonged larvae were developed at different rates by different doses of juvenoids. Larval and pupal mortality rates of the parasite were 6-13 and 4-8% respectively in different treatments. Deformities in reproductive system of the parasitoid were increased or decreased ovariole number, development of compound egg chamber and ill-developed ovariole.

Fatal atypical mycobacterial infection in a cardiac transplant recipient

A 37-year-old female underwent heart transplantation for giant cell myocarditis. The patient died within three-and-a-half months of cardiac transplantation. Postmortem specimens from the heart and lung showed multiple necrotizing granulomas with numerous acid-fast bacilli. Polymerase chain reaction done on both the postmortem samples confirmed the presence of atypical mycobacterial infection. This fatal case of atypical mycobacteriosis in a cardiac transplant patient is reported for its rarity.

Morphogenetic derangements in the reproductive system of Bracon hebetor, a beneficial parasitoid, bred on juvenoid treated host (Corcyra cephalonica) larvae

Effect of juvenoids (hydroprene and methoprene) on the ecto-parasite B. hebetor was investigated by rearing them upon the juvenoid treated ultimate instar host larvae of C. cephalonica. Emerged adultoid wasps of either sexes obtained from treated series showed anatomical deformities in the reproductive systems. Ill-developed ovaries with reduced length, terminally free ovarioles and abnormal testicular growth showing non-fusion of lobes were the important abnormal features. Data on measurements of male reproductive system, e.g., width (transverse axis) of testis, length of common vas deferens plus ejaculatory duct and length of accessory gland showed significant difference (P < 0.05) from control.

The association of suicide attempts and comorbid depression and substance abuse in psychiatric consultation patients

Substance abuse has been associated with attempted suicide and suicide. Few studies have examined the prevalence and associations of combined depression and substance abuse in suicide attempters. A chart review study of 1136 adult general hospital patients referred for psychiatric consultation between 1995 and 1998 was conducted to assess this further. Among 371 cases with self-harm, 311 (84%) attempted suicide. Suicide attempters were younger and diagnosed more often with comorbid substance abuse than patients without self-harm. Depressive disorders were found in 59% and substance abuse disorders in 46%. Comorbid depression and substance abuse was the most frequent category in suicide attempters, i.e., in 37%. Self-reported suicide intent was associated with increasing age, male gender, and comorbid depression and substance abuse. The suicide rate in suicide attempters was 322 per 100,000 patient-years, and 131 per 100,000 in consultation patients without self-harm. It is concluded that comorbid depression and substance abuse is associated with attempted suicide in psychiatric consultation patients. Suicide attempters should be thoroughly assessed for substance abuse. The increased suicide rate in psychiatric consultation patients with and without suicide attempts warrants further research.

Impaired prepulse inhibition of acoustic startle in schizophrenia

BACKGROUND

Schizophrenics show deficits in sensorimotor gating, as measured by prepulse inhibition of acoustic startle (PPI). The goal of this investigation is to further characterize PPI and habituation deficits in schizophrenia, and to examine whether differing subgroups of schizophrenics would show comparable PPI deficits.

METHODS

PPI was measured in 24 male schizophrenic subjects (9 acutely decompensated inpatients and 15 stable outpatients) and in 20 age-matched normal control subjects. Schizophrenic subjects were rated for positive and negative symptoms at the time of testing.

RESULTS

Schizophrenic subjects showed deficits in prepulse inhibition and habituation as compared to normal subjects. Similar latency facilitation was produced by the prepulse in both groups. Acutely decompensated inpatients and stable outpatients did not differ in percent PPI. PPI did not correlate with severity of positive or negative symptoms.

CONCLUSIONS

These results suggest that schizophrenic subjects have impaired central inhibitory mechanisms as measured by PPI, and support the hypothesis that periods of relative clinical remission are not accompanied by normalization of sensorimotor gating.

Bone marrow necrosis in paediatric patients

Necrosis of bone marrow is a very rare condition with a prevalence ranging from 0.15 to 7 percent. It is mostly not compatible with life. We diagnosed four cases of necrotic marrow out of 830 bone marrow aspirations done in last five years of time. All were paediatric patients having peripheral pancytopenia. Three out of four patients expired within one month of diagnosis.

Improved AMBER torsional parameters for the N-N rotational barrier in diacylhydrazines

The structure and rotational barrier for substituted diacylhydrazines are of significant interest given the role this functionality plays in peptidomimetics and ecdysone agonists, the latter of which have application as extremely selective insecticides. Ab initio calculations show that the lowest energy conformations are typically nonplanar with essentially perpendicular nitrogen lone pairs. Molecular mechanics calculations using the AMBER force field in MacroModel yield minima and rotational barriers that are both quantitatively and qualitatively inconsistent with the ab initio results. In this work the AMBER N-N rotational barriers for all configurations of the parent, methyl and di-methyl substituted diformylhydrazines have been fitted to MP2/6-31 + G relative energies. The resulting AMBER torsional parameters have been validated by calculating the rotational barriers for N-t-butyl substituted diformylhydrazine, dibenzoylhydrazine and an azadipeptide. In each case the new AMBER rotational barriers compare favorably with the corresponding MP2 calculated rotational barriers.

Nasal nitric oxide: a comparison of measurement techniques

Nasal nitric oxide measurement may be a surrogate marker of upper airway inflammation. There is, however, no standardized measurement technique; and this led us to examine measurement techniques for acceptability and reproducibility. In five subjects we examined the flow dependence of nasal NO. In 13 healthy volunteers, nasal NO was measured on-line by five methods: 1) Tidal nasal and oral breathing: NO sampling during exclusive nasal followed by exclusive oral tidal breathing; 2) Fixed flow exhalation: NO sampling during exclusive nasal followed by exclusive oral exhalation at 100 mL/second from total lung capacity; 3) Nasal-oral aspiration: air aspirated from the mouth via both nares at 100 mL/second with glottis closure; 4) Aspiration from one nares: air aspirated from one nares at 3.3 mL/second using nitric oxide analyzer sample line with velum closure; 5) Nasal Insufflation: NO sampled at one nares as air insufflated into the other nares at a flow of 100 mL/second with velum closure. Acceptability of all methods was assessed by subjects and technicians. Nasal NO concentration showed a significant inverse correlation with transnasal flow rate. All methods showed excellent reproducibility as assessed by the intraclass correlation coefficient except tidal breathing, which showed highly variable breath-to-breath NO levels, although mean breath values were reproducible. Mean nasal NO concentrations with methods 1, 2, 3, 4, and 5 were 32.1, 50.2, 62.8, 1381, and 60.0 ppb, respectively. Velum closure was not always achieved in methods 4 and 5, whereas methods 1 and 2 required separate nasal and oral procedures. Method 5 had reduced acceptability. NO concentrations were similar with methods that used the same airflow (2, 3, and 5). Nasal NO can be sampled in different ways with excellent reproducibility. In view of the flow dependence of nasal NO, it is vital to use a constant flow rate, and lower airway NO contribution must be excluded or subtracted. The fixed flow exhalation appears to be the preferred method as it is highly reproducible and acceptable.