Clinical evaluation of the mycobacteriophage-based assay in rapid detection of Mycobacterium tuberculosis in respiratory specimens

CONTEXT

Search for a cost-effective, rapid and accurate test has renewed interest in mycobacteriophage as a tool in the diagnosis of tuberculosis (TB). There has been no reported data on the performance of phage assay in a high burden, low-resource setting like Kanpur city, India.

AIMS

To assess the sensitivity and specificity of the FASTPlaque TB kit ability to impact the bacillary load in the phage assay and its performance in the sputum smear sample negative cases.

MATERIALS AND METHODS

The study involved a cross-sectional blinded assessment of phage assay using the FASTPlaque TB kit on 68 suspected cases of pulmonary TB against sputum smear microscopy by Ziehl-Neilsen staining and culture by the LJ method.

RESULTS

The sensitivity, specificity and positive and negative predictive values of the phage assay were 90.7, 96, 97.5 and 85.7%, respectively. The assay was negative in all the five specimens growing mycobacteria other than TB. The sensitivity of the phage assay tended to decrease with the bacillary load. Of the smear-negative cases, three were false negative, and all of which were detected by the phage assay. Smear microscopy (three smears per patient) had a sensitivity and specificity of 93 and 64%, respectively.

CONCLUSIONS

The phage assay has the potential clinical utility as a simple means of rapid and accurate detection of live Mycobacterium tuberculosis bacilli; however, its performance has been inconsistent across various studies, which highlights that the assay requires a high degree of quality control demanding infrastructure and its performance is vulnerable to common adversities observed in "out of research" practice settings like storage, transport and cross-contamination.

Development of carbon/carbon composites with carbon nanotubes as reinforcement and chemical vapor infiltration carbon as matrix

Carbon nanotubes based carbon/carbon composites were prepared by infiltration of purified ACNTs film with pyrolytic carbon. Densification was performed by filling the space between the CNTs through by deposition of the pyrocarbon on the nanotubes surface. It comprised of (i) Synthesis and purification of aligned carbon nanotubes films by CCVD process and (ii) Infiltration of CNTs film by pyrocarbon using CVI method at 950 degrees C. SEM studies showed that the film was well infiltrated using methane. The density of film increased to 1.4 gm/cm3 from 0.4 gm/cm3 of as purified ACNTs film. The I(D)/I(G) ratio for CNTs film is 0.67 and 0.80 for the CVI deposited pyrocarbon. The lower I(D)/I(G) ratio from Raman microscopy shows fine graphitic nature of carbon nanotubes and nanocomposites films.

Fuyuziphine, a new alkaloid from Fumaria indica

A new alkaloid, fuyuziphine together with (+/-)-alpha-hydrastine has been isolated from the whole plant of Fumaria indica. The structures of these alkaloids have been established by spectral and chemical evidences.

Nanoparticle formation by swift heavy ion irradiation of indium oxide thin film

In this study, a novel approach for the formation of indium oxide (IO) nanoparticles by irradiating IO thin film using 100 MeV Ag(8+) ions has been reported. High resolution transmission electron microscopy and energy dispersive x-ray analysis confirm the presence of single-crystalline IO nanoparticles after irradiation. The electronic excitations induced by 100 MeV Ag(8+) ions followed by thermal relaxation of the energy spike in IO thin film is responsible for the formation of latent tracks in the film. The electronic energy loss (S(e)) of 100 MeV Ag(8+) ions in IO is greater than the threshold electronic energy loss (S(eth)) required for the track formation in IO film, but is less than S(eth) required for crystalline silicon. Therefore, the tracks are formed in the IO film and not in the silicon substrate. This results in a stress induced at the IO film and silicon substrate interface which is responsible for dewetting of the tracks and the formation of nanoparticles. The theoretically calculated value of nanoparticle diameter using the thermal spike model is found to be in good agreement with the experimentally observed value of 30 nm.

MRI findings in methanol intoxication: a report of two cases

Methanol is a highly toxic substance and acute methanol poisoning produces severe metabolic acidosis and serious neurological symptoms, including severe visual impairment, extrapyramidal signs and coma. Its similarity to ethanol in appearance and odour leads to accidental use. We present two cases of accidental methanol intoxication and discuss the MRI findings.

Preferred orientation in Ru nanocolumns induced by residual oxygen

Ru nanocolumns were grown on a native oxide covered Si(100) substrate using an oblique angle sputter deposition technique with substrate rotation at room temperature. Scanning tunneling microscopy images of conventional Ru film show the presence of straight columnar features on the film surface, which are very different from the nearly circular features observed on the nanocolumns surface. X-ray diffraction spectra confirm that these nanocolumns have (100) as the preferred orientation instead of the (002) orientation observed for a conventional film. The oxygen to Ru atomic ratio was determined for both the nanocolumns and the conventional film by using X-ray photoelectron spectroscopy. The nanocolumns were observed to incorporate about 6 times more oxygen than the conventional film near the surface region. We argue that the oxygen segregates onto the high-density (002) plane whereas it permeates through comparatively open planes like (100) and (101). The adsorbed oxygen atoms serve as a diffusion barrier for the landing Ru adatoms and inhibit the growth of the (002) plane. This results in the absence of the (002) plane and development of (100) and (101) planes in the nanocolumns. The oxygen plays a decisive role in determining the crystallographic orientation and the feature size/shape over the nanocolumns and conventional film surfaces.

Peptide alkaloids from Zizyphus sativa bark

Two new cyclopeptide alkaloids, sativanine-N and sativanine-O were isolated from the stem bark of Zizyphussativa and their structures were established by spectral analysis.

Reduced fouling and enhanced microbial inactivation during online sterilization of cheese whey using UV coil reactors in series

The effectiveness of coil UV reactor series for the online sterilization of cheese whey was compared to those of the single conventional and coil reactors at various flow rates (5-70 mL/min). The residence time varied from 168 to 12 min and from 48 to 24 min for the single and the series reactors, respectively. Hundred percent destruction efficiency could not be achieved in the single reactors whereas in the coil reactor series the destruction efficiency reached 100% at the flow rates of 35 and 40 mL/min. The rate of microbial destruction was described by polynomial equation for the single coil reactor and by exponential equations for the single conventional reactor and the coil reactor series. The temperature of the effluent decreased with the increase in flow rate in all the reactors. The maximum effluent temperatures in the single conventional reactor, single coil reactor and coil reactor series were 45.8, 46.1, and 36.4 degrees C (Deltat = 20.8, 21.1, 11.4 degrees C), respectively. The flow in all the reactors was laminar (R ( e ) = 1.39-20.10) and the Dean number was in the range of 1.09-15.41 in the coil reactors. Visual observation revealed less fouling on the UV lamps of coil reactors than on that of the conventional reactor due to the impact of Dean flow. The total operating time during which 100% destruction efficiency is achieved prior to the advent of fouling was 240 min in the coil reactor series compared to only 45 min in the conventional reactor.

Random amplified polymorphic DNA (RAPD) analysis of Mycobacterium tuberculosis strains in India

The usefulness of random amplification of polymorphic DNA (RAPD) analysis for typing Indian strains of M. tuberculosis was investigated. M. tuberculosis H37Rv, M. tuberculosis DT and 42 clinical isolates of M. tuberculosis were subjected to RAPD-PCR using 7 random decamer primers. All 7 primers were found to be differentiated and produced specific RAPD profiles. The polymorphic amplicons served as RAPD markers for M. tuberculosis. The dendrograms, obtained by different primers, showed the discriminatory ability of the primers. RAPD analysis provided a rapid and easy means of identifying polymorphism in M. tuberculosis isolates, and it was found to be a valuable alternative epidemiological tool. In addition, the results of the present study showed heterogeneity in the M. tuberculosis strains in the population studied.

Flavonoids from Echinops echinatus

A new isoflavone glycoside, echinoside (7), together with 7-hydroxyisoflavone, kaempferol-4'-methylether, kaempferol-7-methylether, myrecetin-3-O-alpha-L-rhamnoside, kaempferol and kaempferol-3-O-alpha-L-rhamnoside, has been isolated from the whole plant of Echinops echinatus. The structure of echinoside has been established by chemical and spectral data. This is the first report of the occurrence of these flavonoids in E. echinatus.

Thrombin and PAR-1 stimulate differentiation of bone marrow-derived endothelial progenitor cells

Endothelial progenitor cells (EPCs) from the bone marrow play an important role in vascular response to injury and ischemia. The mediators involved in the mobilization, recruitment, proliferation and differentiation of EPCs are not fully understood. In this study, the role of coagulation factor thrombin and protease-activated receptor-1 (PAR-1) on bone marrow-derived cell proliferation and differentiation was investigated. Bone marrow cells (BMCs) were isolated from C57/BL6 mice and plated on fibronectin-coated flasks. Cell characteristics, proliferation and the expression of endothelial cell markers were determined using immunohistochemistry, thymidine uptake and fluorescence activated-cell sorting (FACS), respectively. The results show that thrombin stimulated enrichment of bone marrow cells with endothelial morphology, exhibiting acetylated-low-density lipoprotein (LDL) uptake and isolectin staining. Thrombin or PAR-1-activating peptide produced a 2- to 3-fold increase in the total number of cells as well as an increase in vascular endothelial (VE)-cadherin-positive cells. Thrombin treatment of VE-cadherin-negative cells prepared after cell sorting resulted in the generation of 3- to 4-fold higher VE-cadherin-positive cells than the untreated cultures. Increase in VE-cadherin-positive cells was inhibited by hirudin and efegatran. These results provide first evidence for a novel activity of thrombin and PAR-1 on bone marrow progenitor cell proliferation and EPC differentiation, and suggest their potential role in vascular regeneration and recanalization of thrombus.

Early tracheostomy in closed head injuries: experience at a tertiary center in a developing country--a prospective study

BACKGROUND

An important factor contributing to the high mortality in patients with severe head trauma is cerebral hypoxia. The mechanical ventilation helps both by reduction in the intracranial pressure and hypoxia. Ventilatory support is also required in these patients because of patient's inability to protect the airway, persistence of excessive secretions, and inadequacy of spontaneous ventilation. Prolonged endotracheal intubation is however associated with trauma to the larynx, trachea, and patient discomfort in addition to requirement of sedatives. Tracheostomy has been found to play an integral role in the airway management of such patients, but its timing remains subject to considerable practice variation. In a developing country like India where the intensive care facilities are scarce and rarely available, these critical patients have to be managed in high dependency cubicles in the ward, often with inadequately trained nursing staff and equipment to monitor them. An early tracheostomy in the selected group of patients based on Glasgow Coma Score(GCS) may prove to be life saving. Against this background a prospective study was contemplated to assess the role of early tracheostomy in patients with isolated closed head injury.

METHODS

The series consisted of a cohort of 50 patients admitted to the surgical emergency with isolated closed head injury, that were not considered for surgery by the neuro-surgeon or shifted to ICU, but had GCS score of less than 8 and SAPS II score of more than 50. First 50 case records from January 2001 that fulfilled the criteria constituted the control group. The patients were managed as per ATLS protocol and intubated if required at any time before decision to perform tracheostomy was taken. These patients were serially assessed for GCS (worst score of the day as calculated by senior surgical resident) and SAPS scores till day 15 to chart any changes in their status of head injuries and predictive mortality. Those patients who continued to have a GCS score of <8 and SAPS score of >50 for more than 24 hours (to rule out concussion or recovery) underwent tracheostomy. All these patients were finally assessed for mortality rate and hospital stay, the statistical analysis was carried out using SPSS10 version. The final outcome (in terms of mortality) was analyzed utilizing chi-square test and p value <0.05 was considered significant.

RESULTS

At admission both tracheostomy and non-tracheostomy groups were matched with respect to GCS score and SAPS score. The average day of tracheostomy was 2.18 +/- 1.0038 days. The GCS scores on days 1, 2, 3, 4, 5, 10 between tracheostomy and non-tracheostomized group were comparable. However the difference in the GCS scores was statistically significant on day 15 being higher in the tracheostomy group. Thus early tracheostomy was observed to improve the mortality rate significantly in patients with isolated closed head injury.

CONCLUSION

It may be concluded that early tracheostomy is beneficial in patients with isolated closed head injury which is severe enough to affect systemic physiological parameters, in terms of decreased mortality and intubation associated complications in centers where ICU care is not readily available. Also, in a selected group of patients, early tracheostomy may do away with the need for prolonged mechanical ventilation.

Half versus full vacuum suction drainage after modified radical mastectomy for breast cancer- a prospective randomized clinical trial[ISRCTN24484328]

Background

Suction drains are routinely used after modified radical mastectomy and are an important factor contributing to increased hospital stay as the patients are often discharged only after their removal. Amongst various factors that influence the amount of postoperative drainage, the negative suction pressure applied to the drain has been reported to be of great significance. While a high negative suction pressure is expected to drain the collection and reduce the dead space promptly, it may also prevent the leaking lymphatics from closing and lead to increased drainage from the wound. Against this background a prospective randomized clinical study was conducted to compare the amount and duration of drainage between a half negative suction and full vacuum suction drainage in patients following modified radical mastectomy. The associated postoperative morbidity was also compared between the two groups.

Methods

85 FNAC (fine needle aspiration cytology) proven cases of locally advanced breast cancer were randomized. (Using randomly ordered sealed envelops, which were opened immediately before the closure of the wound) in to 50 patients with full vacuum suction (pressure = 700 g/m2) and 35 cases in to half vacuum suction drainage (pressure = 350 g/m2) groups. The two groups were comparable in respect of age, weight, and technique of operation and extent of axillary dissection. Surgery was performed by the same surgical team comprising of five surgeons (two senior and three resident surgeons) using a standardized technique with electrocautery. External compression dressing was provided over the axilla for first 48 hrs and following that patients were encouraged to do active and passive shoulder exercises. The outcomes measured were postoperative morbidity and the length of hospital stay.

Statistical methods used: Descriptive studies were performed with SPSS version 10 and group characteristics were compared using student t-test.

Results

Half vacuum suction drains were removed earlier than the full suction vacuum suction drains. There was no significant difference in the incidence of seroma formation in the two groups and there was a significant reduction in the total hospital stay in patients with half vacuum suction drainage systems as compared to the full suction drainage group (p < 0.001) without any added morbidity.

Conclusions

Half negative suction drains provide an effective compromise between no suction and full or high suction drainage after modified radical mastectomy by reducing the hospital stay and the post operative morbidity including post operative seromas.

Is drug-induced toxicity a good predictor of response to neo-adjuvant chemotherapy in patients with breast cancer?--a prospective clinical study

BACKGROUND

Neo-adjuvant chemotherapy is an integral part of multi-modality approach in the management of locally advanced breast cancer and it is vital to predict the response in order to tailor the regime for a patient. The common final pathway in the tumor cell death is believed to be apoptosis or programmed cell death and chemotherapeutic drugs like other DNA-damaging agents act on rapidly multiplying cells including both the tumor and the normal cells by following the same common final pathway. This could account for both the toxic effects and the response. Absence or decreased apoptosis has been found to be associated with chemo resistance. The change in expression of apoptotic markers (Bcl-2 and Bax proteins) brought about by various chemotherapeutic regimens is being used to identify drug resistance in the tumor cells. A prospective clinical study was conducted to assess whether chemotherapy induced toxic effects could serve as reliable predictors of apoptosis or response to neo-adjuvant chemotherapy in patients with locally advanced breast cancer.

METHODS

50 cases of locally advanced breast cancer after complete routine and metastatic work up were subjected to trucut biopsy and the tissue evaluated immunohistochemically for apoptotic markers (bcl-2/bax ratio). Three cycles of Neoadjuvant Chemotherapy using FAC regime (5-fluorouracil, adriamycin, cyclophosphamide) were given at three weekly intervals and patients assessed for clinical response as well as toxicity after each cycle. Modified radical mastectomy was performed in all patients three weeks after the last cycle and the specimen were re-evaluated for any change in the bcl-2/bax ratio. The clinical response, immunohistochemical response and the drug-induced toxicity were correlated and compared. Descriptive studies were performed with SPSS version 10 and the significance of response was assessed using paired t-test. Significance of correlation between various variables was assessed using chi-square test and coefficient of correlation calculated by Pearson correlation coefficient.

RESULTS

There was a statistically significant correlation observed between clinical, immunohistochemical response (bcl-2/bax ratio) and the drug-induced toxicity.

CONCLUSION

Responders also had significant toxicity while non-responders did not show significant toxicity following neoadjuvant chemotherapy. The chemotherapy-induced toxicity was observed to be a cost effective and reliable predictor of response to neo-adjuvant chemotherapy.

Squamous cell carcinoma developing in the scar of Fournier's gangrene--case report

BACKGROUND

Squamous cell carcinoma of the scrotum is rare and its development in the scar of Fournier's gangrene is still rarer.

CASE PRESENTATION

A 65-year-old gentleman presented with a small non-healing ulcer developing on right hemi-scrotum two years after the treatment for Fournier's gangrene. On histological examination it was found to be squamous cell carcinoma. He was successfully managed by surgery in the form of wide local excision and ilio-inguinal lymph node dissection followed by adjuvant radiotherapy and chemotherapy.

CONCLUSIONS

Squamous cell carcinoma can develop in the scar of Fournier's gangrene after a long delay, which differentiates it from other scar carcinomas or Marjolin's ulcer.

Chemopreventive efficacy of selenium against N-nitrosodiethylamine-induced hepatoma in albino rats

The chemopreventive/chemotherapeutic effect of sodium selenite on tricarboxylic acid cycle key enzymes was investigated against hepatoma induced by environmental carcinogen N-nitrosodiethylamine. Decreased activities of TCA cycle key enzymes such as isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH) and alpha-ketoglutarate dehydrogenase (alpha-KGDH) in hepatoma and surrounding tissues of hepatoma-bearing rats were observed. Upon selenium supplementation the above biochemical changes were reverted in a dose- and duration-dependent manner. This study further confirms the chemopreventive/chemotherapeutic effect of sodium selenite which is found to be more effective in the initiation phase of carcinogenesis.