Role of Gene Xpert in smear negative pulmonary tuberculosis

BACKGROUND

Tuberculosis is a major health problem contributing to significant morbidity and mortality. Early diagnosis and treatment is the key for TB control. Sputum microscopy is a rapid and inexpensive test but due to low and variable sensitivity, many cases can be missed. Culture is considered to be the gold standard but is time consuming. Gene Xpert is a novel and rapid cartridge based nucleic acid amplification test (CBNAAT) that can be used for prompt diagnosis.

AIM

To compare the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Gene Xpert with culture in diagnosing tuberculosis in sputum smear negative patients.

METHODS

The study is a prospective observational study conducted from December 2017 to January 2019 on 189 patients, who were sputum smear negative but had signs and symptoms suggestive of tuberculosis. Their respiratory samples were taken (either sputum or bronchoalveolar lavage) and sent for Gene Xpert. The results were compared with culture, which was taken as the gold standard, and diagnostic accuracy was assessed.

RESULT

A total of 189 patients were included in the study. In 25 patients sputum was taken and in 164 patients BAL was taken (which included 22 patients in whom sputum Gene Xpert was negative but there was high clinical suspicion of tuberculosis). The sensitivity, specificity, PPV and NPV of Gene Xpert in diagnosing smear negative pulmonary tuberculosis was found to be 96.3%, 81.3%, 87.5% and 94.2% respectively.

CONCLUSION

Gene Xpert can be used as a rapid diagnostic tool in patients who are sputum smear negative but have clinical features highly suggestive of tuberculosis. It additionally helps in detecting rifampicin resistance. But every Gene Xpert positive case does not necessarily mean an active disease, therefore, past history of tuberculosis along with radiological signs of disease activity are to be considered. In case of negative Gene Xpert but high clinico-radiological suspicion of TB, patients should be followed up on regular intervals, while awaiting their culture.

Indian Guidelines on Nebulization Therapy

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

Germline ATM variants predispose to melanoma: a joint analysis across the GenoMEL and MelaNostrum consortia

PURPOSE

Ataxia-Telangiectasia Mutated (ATM) has been implicated in the risk of several cancers, but establishing a causal relationship is often challenging. Although ATM single-nucleotide polymorphisms have been linked to melanoma, few functional alleles have been identified. Therefore, ATM impact on melanoma predisposition is unclear.

METHODS

From 22 American, Australian, and European sites, we collected 2,104 familial, multiple primary (MPM), and sporadic melanoma cases who underwent ATM genotyping via panel, exome, or genome sequencing, and compared the allele frequency (AF) of selected ATM variants classified as loss-of-function (LOF) and variants of uncertain significance (VUS) between this cohort and the gnomAD non-Finnish European (NFE) data set.

RESULTS

LOF variants were more represented in our study cohort than in gnomAD NFE, both in all (AF = 0.005 and 0.002, OR = 2.6, 95% CI = 1.56-4.11, p < 0.01), and familial + MPM cases (AF = 0.0054 and 0.002, OR = 2.97, p < 0.01). Similarly, VUS were enriched in all (AF = 0.046 and 0.033, OR = 1.41, 95% CI = 1.6-5.09, p < 0.01) and familial + MPM cases (AF = 0.053 and 0.033, OR = 1.63, p < 0.01). In a case-control comparison of two centers that provided 1,446 controls, LOF and VUS were enriched in familial + MPM cases (p = 0.027, p = 0.018).

CONCLUSION

This study, describing the largest multicenter melanoma cohort investigated for ATM germline variants, supports the role of ATM as a melanoma predisposition gene, with LOF variants suggesting a moderate-risk.

Clinico-radiological profile of COVID-19 in Kashmiri population: A descriptive study

Aim

The purpose of our study was to assess the presentation of COVID-19 disease in terms of clinical and radiological features in our population.

Methods

64 RT-PCR documented COVID-19 patients were included in the study. Clinical, biochemical, and radiological data were collected and analyzed retrospectively from last week of March to 30^th April 2020.

Results

Out of the 64 patients, 38 (59.4%) were males, 44 (68.7%) had a history of contact with COVID-19 positive patient. 26.6%patients were in the age group of 21-30 years. 53.1% patients were asymptomatic while as cough and fever were the most common symptoms in 21.8 and 20.3% patients, respectively. Anosmia was present in four patients. Hypertension and hypothyroidism were the most common comorbid illnesses among the study population in 9.4% patients each. Lymphopenia was present in 38% of patients CRP was increased in 83% patients, LDH in 90.2%, and ferritin in 51.5% of patients. 17 (26.6%) patients had bilateral disease in CT. RUL was the most common lobe involved in 18 (28.1%) patients. GGO and consolidation were seen in 22 (34.45) and 13 (20.3%) patients, respectively. Vessel enlargement was observed in 11 (17.2%) patients. All five lobes were involved in 9 (14.1%) patients. Five patients developed severe disease with respiratory comprise; two of them eventually died.

Conclusion

The clinical and radiological characteristics of COVID-19 patients vary among different populations. Although there are no radiological features which seems to be characteristic of COVID-19, but CT helps in evaluation of the patients as many asymptomatic ones have some radiological findings suggestive of viral pneumonia.

Spectrum of chest CT manifestations of coronavirus disease (COVID-19): A pictorial essay

Coronavirus disease (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is an enveloped single-stranded RNA virus belonging to the family of betacoronaviruses. Chest computed tomography (CT) has helped us in understanding this new disease. Typical CT features of COVID-19 pneumonia are ground-glass opacities (GGO), crazy paving pattern and GGO with superimposed consolidation with a basal, posterior and peripheral lung predilection. Less commonly bronchial wall thickening, bronchial dilatation and pleural thickening are seen. Presence of pleural effusion, pericardial effusion and mediastinal lymphadenopathy is seen in severe cases. Reticulations, fibrous stripes, reverse halo sign and perilobular opacities are seen late (>2 weeks) in the course of illness. We aim to present a pictorial review of CT imaging findings in COVID-19 to illustrate the typical and atypical manifestations of this disease in a bid to familiarize radiologists with the myriad imaging manifestations of this disease.

Secondary solid cancer screening following hematopoietic cell transplantation

Hematopoietic stem cell transplant (HCT) recipients have a substantial risk of developing secondary solid cancers, particularly beyond 5 years after HCT and without reaching a plateau overtime. A working group was established through the Center for International Blood and Marrow Transplant Research and the European Group for Blood and Marrow Transplantation with the goal to facilitate implementation of cancer screening appropriate to HCT recipients. The working group reviewed guidelines and methods for cancer screening applicable to the general population and reviewed the incidence and risk factors for secondary cancers after HCT. A consensus approach was used to establish recommendations for individual secondary cancers. The most common sites include oral cavity, skin, breast and thyroid. Risks of cancers are increased after HCT compared with the general population in skin, thyroid, oral cavity, esophagus, liver, nervous system, bone and connective tissues. Myeloablative TBI, young age at HCT, chronic GVHD and prolonged immunosuppressive treatment beyond 24 months were well-documented risk factors for many types of secondary cancers. All HCT recipients should be advised of the risks of secondary cancers annually and encouraged to undergo recommended screening based on their predisposition. Here we propose guidelines to help clinicians in providing screening and preventive care for secondary cancers among HCT recipients.

Abstract P6-09-02: Improved clinical outcomes associated with vitamin D supplementation during adjuvant chemotherapy in patients with HER2+ non-metastatic breast cancer

Background

Vitamin D (VitD) supplementation decreases the risk of osteoporotic fractures in the elderly; however, its extraskeletal benefits, especially in the prevention and treatment of breast cancer, are less well-established. Many studies have shown an association of low VitD levels with higher cancer incidence, including breast cancer and poorer outcomes, but whether this association merely reflects a selection bias to healthier lifestyles, remains an area of controversy. We hypothesized that women with more aggressive HER2+ breast cancer would have improved clinical outcomes while on VitD supplements.

Methods

We performed a retrospective review of all patients (n = 300) given trastuzumab chemotherapy between 2006 and 2012 at UM/SCCC. We identified two groups of patients for comparison - those who received VitD supplementation (VD) during adjuvant chemotherapy (n = 130) or none (NVD) during adjuvant chemotherapy (n = 123). Patients who lacked sufficient records to clarify VitD supplement use, men, patients with de-novo-metastatic breast cancer, bilateral breast cancers, and patients without follow-up were excluded. Five-year disease-free survival (DFS) and overall survival (OS) were calculated. Univariate and multivariate analyses were performed using a Cox proportional hazards (CPH) model to evaluate the relationship between VD supplementation and death.

Results

The median age at diagnosis was 54 and 50 in the VD and NVD groups. In the VD group, the average VitD dose was 10,890 IU/wk, and the baseline and post-25-H VitD serum level was 35 and 41ng/ml, respectively. Descriptive analysis of the VD and NVD groups were as follows: postmenopausal (55.4%, 43.9%), tumor &lt;2cm (42.3%, 36.6%), no lymph node involvement (42.3%, 36.6%), LVI (46.4%, 33.3%), high nuclear grade (60%, 61.5%), HR+ (66.2%, 54.5%), African American race (4.6%, 9.8%), and BMI&gt;30 at end of chemotherapy (26.2%, 31.7%). At a median follow-up of 31 and 23 months, the estimated five-year DFS (69.4% vs. 44.7%, p = 0.009) and OS (97.5% vs. 85.6%, p = &lt;0.0001) were significantly superior in the VD group versus the NVD group. These differences remained significant after adjustment for age, ethnicity, menopausal state, tumor size, node positivity, LVI, high-grade tumor, HR+, and BMI&gt;30. Analysis showed an interaction between OS and ethnicity (African American = 0.008) and node positivity (p = 0.02) and near-significance for LVI (p = 0.07). Despite those confounding variables, VitD use remained significantly associated with improved OS (p = 0.003) and had a HR or 0.10 with a 95% CI of 0.02-0.45.

Conclusion

Our study suggests that Vitamin D supplementation in non-metastatic HER2 breast cancer patients is associated with improved DFS and OS, and the relationship remains significant after adjusting for potential confounding factors. It is unclear whether vitamin D supplementation might have pre-selected for HER2+ breast cancers with more favorable prognosis or synergized with anti-HER2 therapy. To our knowledge, this is the first study reporting improved outcomes associated with relatively high dose Vitamin D supplementation in the HER2+ breast cancer population. Further research is warranted to define the role of Vitamin D in breast cancer treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-09-02.

Hydroxyapatite-ceramic-coated femoral components in young patients followed-up for 16 to 19 years: an update of a previous report

In 2004 we described the ten-year prospective results of 38 total hip replacements using the Furlong hydroxyapatite-ceramic-coated femoral component in 35 patients < 50 years old. We have now reviewed the surviving 35 arthroplasties in 33 patients at a mean of 16 years (10.3 to 19.9). The mean age of the surviving patients at the time of operation was 41.3 years (26.0 to 49.0). Of these, eight have undergone revision of their acetabular component for aseptic loosening. None of the femoral components has had revision for aseptic loosening giving a survival rate of 100% at 16 years (95% confidence interval 89% to 100%). The Furlong hydroxyapatite-ceramic-coated femoral component gives excellent long-term survival in young and active patients.

A real-time approach to detect seal defects in food packages using ultrasonic imaging

The microbial integrity of many types of flexible food packages depends on a zero defect level in the fused seam seal. Human inspection for defects in these seals is marginal at best, and secondary incubation protocols are often used to spot packages with compromised integrity before releasing product for sale. A new type of inspection method has been developed and is being evaluated for robustness. The purpose of the study was to evaluate a new raster scanning geometry to simulate continuous motion, online ultrasonic inspection of the seal region in flexible food package seals. A principal engineering tradeoff of scanning inspection systems is between increased line speed that results from decreased spatial sampling (less acquired data to process) and decreased image quality. The previously developed pulse-echo Backscattered Amplitude Integral (BAI) mode imaging technique is used to form ultrasound images using the new scanning geometry. At an ultrasonic frequency of 22.9 MHz, 38- and 50-microm-diameter air-filled channel defects in all-plastic transparent trilaminate are evaluated. The contrast-to-noise ratio (CNR) of the processed BAI-mode image is used to quantify image quality as a function of spatial sampling. Results show seal defects (38- and 50-microm diameter) are still detectable for undersampled conditions, although image quality degrades as spatial sampling decreases. Further, it is concluded that the raster scanning geometry is feasible for online inspection.

Shape of the acromion: congenital or acquired--a macroscopic, radiographic, and microscopic study of acromion

Debate continues as to whether the differing shapes of the acromion are congenital or acquired. This has been investigated by neonatal cadaver study, adult cadaver study, radiographic study, magnetic resonance imaging study, or various other means. No one, to our knowledge, has investigated this by histologic study. A macroscopic and histologic study of 22 cadaveric shoulder joints was carried out to establish what, if any, developmental changes occur in the differing patterns of acromion. The cadaveric shoulders were dissected and examined macroscopically. All of the acromion processes were transected and photographed, and the histology of the anterior and inferior surfaces was studied. In all of the curved and hooked types of acromion, a common pattern of degeneration of collagen, fibrocartilage, and bone was observed, consistent with a traction phenomenon. None of the flat acromions exhibited these changes. Extensive histologic changes were noted on the anterior surface of acromion as compared to the inferior surface in curved or hooked acromion. We conclude that the different shapes of acromion are, therefore, acquired as a response to traction forces applied via the coracoacromial ligament and are not congenital in origin.

Sub-biochemical hypothyroidism: an exaggerated thyroid stimulating hormone response to thyrotrophin releasing hormone

BACKGROUND

The availability of sensitive and specific assays for evaluation of the thyroid axis has allowed definition of thyroid disorders at subclinical stage. This has almost obviated the use of thyrothrophin releasing hormone (TRH) study. We describe here a group of patients with minimal signs of hypothyroidism having normal thyroid function tests (T3, T4, thyroid stimulating hormone (TSH)) and have shown exaggerated TSH response to TRH.

MATERIAL AND METHODS

Total 82 subjects were studied. Of these, 11 were age and sex matched controls, and 71 were patients. In all subjects TSH and other thyroid assays (T3, T4, FT4) were done by immunoradiometric assay (IRMA), and radioimmunoassay (RIA) respectively. Thyroid antibody was carried out by haemagglutination method. Results were compared to age and sex related normal ranges. To further investigate the status of thyroid axis, TRH study was carried out using standard protocol.

RESULTS

Based on TRH study patients were grouped in three categories. Group 1 included 29 patients whose TSH response to TRH was normal. Group 2 included 20 patients with normal baseline TSH and exaggerated TSH response to TRH and Group 3 included 18 patients with baseline TSH in the range of 5 to 10 mu IU/ml and exaggerated TSH response to TRH. There was a significant difference to total T3 between group 1 and 3 (p < 0.05) but mean values were within normal limits. While no significant difference was observed in total T4 between controls and patient's group. Serum TSH values were high in group 3 as compared to controls and Group 1 and 2 (p < 0.0001). For Free T4 no statistical significance was observed between Group 1, 2 and 3. Thyroid antibodies were positive in 22.7% of patients in Group 2 and 33.33% in Group 3.

CONCLUSION

We conclude from the present study that even with sensitive TSH assays TRH study still has a role to mark the early stage of hypothyroidism. Those with a normal or upper normal TSH with exaggerated response to TRH are termed as sub-biochemical hypothyroidism and can be considered for thyroid replacement therapy.

Optimization of a hydrophobic solid-phase extraction interface for matrix-assisted laser desorption/ionization

Matrix-assisted laser desorption/ionization (MALDI) probe surfaces derivatized with octadecanethiol (C18) can be used as hydrophobic solid-phase extraction devices to isolate and desalt biopolymers directly on the probe surface. Using quantitative MALDI, it was possible to determine the approximate amount of peptide that bound to C18 surfaces and thus to calculate a surface density. It was determined that the amount of peptide bound at the probe surface was independent of the analyte concentration in the immersion solution (from high- to sub-ng ml-1 concentrations), but rather was dependent on the immersion time of the surface as it was exposed to the analyte. The capacity of C18-derivatized probes to bind biopolymers in fixed amounts frees the analyst from the necessity for adjusting analyte concentration through multiple step procedures such as serial dilution or vacuum drying. This time savings result in an overall increase in the efficiency of the MALDI technique.

Differential effects of estradiol and its analogs on cyclin D1 and CDK4 expression in estrogen receptor positive MCF-7 and estrogen receptor-transfected MCF-10AEwt5 cells

Estradiol stimulates the growth of a majority of human breast tumors containing the estrogen receptors (ERs), proteins that mediates estrogen function. Opposing effects of estradiol have been found in cells expressing endogenous ER and those containing a transfected ER. To understand the role of estradiol structure in diverse estrogenic responses related to cell cycle regulation, we evaluated the effects of estradiol and its analogs on cell cycle progression, and the expression of cyclin D1 and the cyclin dependent kinase 4 (CDK4) in ER-positive MCF-7 and ER-transfected MCF-10AEwt5 cells. Four analogs of estradiol, with a re-positioned or a deleted hydroxyl group, were used. Our results show that estradiol and all of the analogs facilitated cell cycle progression of MCF-7 cells. In contrast, only estradiol inhibited the cell cycle progression of MCF-10AEwt5 cells significantly. Western blot analysis revealed that cyclin D1 protein increased to the maximal level by 6 h after the initiation of cell cycle from G1 phase of MCF-7 cells. The least effective analog in inducing cyclin D1 was 3-hydroxyestratriene. However, this analog was most effective at inducing CDK4, contributing to its efficacy in facilitating MCF-7 cell cycle. In contrast to MCF-7 cells, the level of cyclin D1 protein was not influenced significantly by estradiol or its analogs in MCF-10AEwt5 cells. Sucrose gradient sedimentation analysis of ER from MCF-7 cells showed that the major peak of [3H]-estradiol bound to ER could be displaced by a 10-fold excess of unlabelled estradiol or any of the analogs. In contrast, several analogs were less effective than unlabelled estradiol in competitive displacement of [3H]-estradiol bound to ER from MCF-10AEwt5 cells. These data indicate that the induction of cyclin D1 is an important part of the growth stimulatory effects of estrogens in MCF-7 cells, but it may not be involved in growth inhibition of MCF-10AEwt5 cells. Our results also show that estrogenic compounds interact with ER from MCF-10AEwt5 cells with altered ligand binding affinity, possibly due to the absence or dysfunction of certain transcription factors or ER-associated proteins that co-regulate ER function.

Alprazolam-reinforced medication use in outpatients with anxiety

The reinforcing effects of alprazolam were investigated in 14 patients who had generalized anxiety or panic disorder, but were not current users/abusers of other psychoactive substances. Using a double-blind outpatient choice procedure, color-coded alprazolam (0.5 mg) and placebo capsules were provided to patients for use 'as needed' in the treatment of anxiety symptoms. Comparisons of alprazolam and placebo during a 2 week sampling period in which placebo and alprazolam were available sequentially revealed no significant differences on measures of medication usage or anxiety levels, although alprazolam did increase subjective ratings of drug effects side effects. During a 4 week choice period, alprazolam was strongly preferred over placebo in 11 out of 14 patients indicating that alprazolam functioned as a reinforcer. Medication usage ranged from zero to 4.0 mg alprazolam in a day. Variations in daily medication-use were positively correlated with anxiety level fluctuations for a majority of patients. For a majority of patients, the results indicate that alprazolam functioned as a reinforcer without accompanying signs of abuse or addiction.

Structural brain scanning in psychiatric patients: a further look

BACKGROUND

Indications for computed tomographic (CT) and magnetic resonance (MR) scans of the brain in psychiatric patients are not clearly defined. This survey attempted to refine indications suggested by an earlier survey.

METHOD

All brain scans ordered in a psychiatric teaching hospital were surveyed over a period of approximately 23 months. A revised order sheet provided information about the assumed need for scanning as well as indicated those factors from the previous survey most likely to reveal pertinent information. Scan results were later correlated with this information.

RESULTS

Of 68 scans reviewed, 40 were normal, 16 equivocal, and 12 were abnormal. Cognitive decline and/or confusion were indications for 30 scans; 7 were abnormal, all meriting a clinical diagnosis of Alzheimer dementia. Only 1 of 12 scans to investigate a history of head injury was abnormal. Only 2 of 11 scans based on a history of seizures were abnormal; all had other possible indications. In one patient a prior stroke was confirmed, and in another, active multiple sclerosis. Ten of the group of 12 abnormal scans were found in patients over the age of 40 years, emphasizing the influence of age.

CONCLUSION

Revised indications based on this second survey were as follow: (1) The importance of new or unexplained focal neurologic signs was confirmed; (2) Scans are useful for bolstering a clinical diagnosis of Alzheimer disease; (3) A first psychotic break or personality change after the age of 50 years will require investigation; (4) Cognitive decline in a patient with a prior history of functional psychosis is most likely part of the psychosis rather than a confounding organic disorder; (5) Isolated seizures of long duration or abnormal EEG without other clinical findings are seldom associated with abnormal scans.

Comparative bioavailability of slow release diclofenac (Voveran SR) with enteric coated tablet and internationally used Voltaren Retard

The objective of the study was to compare the enteric coated diclofenac sodium (Voveran), the slow release formulation developed in India (Voveran SR) and the internationally marketed formulation Voltaren Retard. Ten healthy volunteers were administered 100 mg each of the three formulations in a three-way crossover fashion. Blood samples were collected over 24 hours following administration of the drug; plasma levels of unchanged drug were determined by gas chromatography. Pharmacokinetic parameters for the three formulations were compared. The extent of the drug available from the three formulations was the same as the mean AUC values were not significantly different. Cmax and MRT values for the two slow release formulations were comparable but were significantly different from the values obtained with the enteric coated formulation. Tmax values for the two slow release formulations were similar while the enteric coated tablet had faster time to peak. Voveran SR is comparable to Voltaren Retard and has the distinct advantage of a slow release formulation in that its Cmax is much lower and levels are maintained over 12 hours and detectable upto 24 hours. This slow release formulation will offer clinical advantages of better compliance, relief of early morning symptoms and better tolerability over long term usage.

Partial Purification and Characterization of Two Hydrogenases from the Extreme Thermophile Methanococcus jannaschii

F 420 -nonreactive and F 420 -reactive hydrogenases have been partially purified from Methanococcus jannaschii , an extremely thermophilic methanogen isolated from a submarine hydrothermal vent. The molecular weights of both hydrogenases were determined by native gradient electrophoresis in 5 to 27% polyacrylamide gels. The F 420 -nonreactive hydrogenase produced one major band (475 kilodaltons), whereas the F 420 -reactive hydrogenase produced two major bands (990 and 115 kilodaltons). The F 420 -nonreactive hydrogenase consisted of two subunits (43 and 31 kilodaltons), and the F 420 -reactive hydrogenase contained three subunits (48, 32, and 25 kilodaltons). Each hydrogenase was active at very high temperatures. Methyl viologen-reducing activity of the F 420 -nonreactive hydrogenase was maximal at 80°C but was still detectable at 103°C. The maximum activities of F 420 -reactive hydrogenase for F 420 and methyl viologen were measured at 80 and 90°C, respectively. Low but measureable activity toward methyl viologen was repeatedly observed at 103°C. Moreover, the half-life of the F 420 -nonreactive hydrogenase at 70°C was over 9 h, and that of the F 420 -reactive enzyme was over 3 h.

Pressure and Temperature Effects on Growth and Methane Production of the Extreme Thermophile Methanococcus jannaschii

The marine archaebacterium Methanococcus jannaschii was studied at high temperatures and hyperbaric pressures of helium to investigate the effect of pressure on the behavior of a deep-sea thermophile. Methanogenesis and growth (as measured by protein production) at both 86 and 90°C were accelerated by pressure up to 750 atm (1 atm = 101.29kPa), but growth was not observed above 90°C at either 7.8 or 250 atm. However, growth and methanogenesis were uncoupled above 90°C, and the high-temperature limit for methanogenesis was increased by pressure. Substantial methane formation was evident at 98°C and 250 atm, whereas no methane formation was observed at 94°C and 7.8 atm. In contrast, when argon was substituted for helium as the pressurizing gas at 250 atm, no methane was produced at 86°C. Methanogenesis was also suppressed at 86°C and 250 atm when the culture was pressurized with a 4:1 mix of H 2 and CO 2 , although limited methanogenesis did occur when the culture was pressurized with H 2 .

Comparison of left atrial size and pulmonary capillary pressure with P wave of electrocardiogram

The amplitude and duration of P waves in Leads II (P II), P terminal force in V1, (PV1) and the sums of P II and PV1 were compared in 37 subjects with left atrial size obtained by echocardiographic technique in 36 instances and with hemodynamic estimates of pulmonary capillary wedge pressures in 16 cases. The 22 females and 15 males were subdivided into the following groups. Group I, four normal subjects, Group II, 11 patients with predominant aortic insufficiency (two of whom had a mild mitral insufficiency); Group III, 14 patients with mitral valve disease, seven of whom had mitral insufficiency (two with minimal aortic insufficiency) Group IIIa) and seven had mitral stenosis (Group IIIb); Group IV, eight patients with miscellaneous disorders, i.e., coronary artery disease (5), hypertension (2), and idiopathic hypertrophic subaortic stenosis (1). Good correlations were obtained between left atrial size and P in Lead II (P II) (r = 0.74; p less than 0.001) and between P terminal force in V1 (PV1) and left atrial size (r = -0.69; p less than 0.001). In Group IV good correlation between PV1 and atrial size was noted. Some correlation between the sum of P II and PV1 and left atrial size (r = 0.51; p less than 0.02) was noted, but a better correlation was obtained in the patients with aortic insufficiency (r = 0.80; p less than 0.01). Pulmonary capillary wedge pressures were not reflected in changes in P II or PV1, except for the group with mitral stenosis (Group IIIb). Adding P II to PV1 improved the correlation with wedge pressure for the entire group.