Prospective glioma grading using single-dose dynamic contrast-enhanced perfusion MRI

AIM

To evaluate the sensitivity and specificity of single-dose dynamic contrast-enhanced (DCE) perfusion magnetic resonance imaging (MRI) in prospective evaluation of glioma grading and to correlate the relative cerebral blood volume (rCBV) values with mitotic and ki-67 indexes obtained at histopathology.

MATERIALS AND METHODS

A total of 53 histologically proven patients with glioma were included in this study. DCE-MRI perfusion with a single dose of contrast medium was included in brain tumour protocol and prospective grading of glioma into low and high grade was done based on a previously reported rCBV cut-off value of 3. Tumours with rCBV ≥ 3 were considered to be high grade and rCBV < 3 were considered to be low grade. The sensitivity and specificity of the cut-off value were estimated. Ki-67 and mitotic indexes were also obtained on histopathological analysis along with histological grading.

RESULTS

Based on pre-defined rCBV cut-off values, prospective grading of low- and high-grade glioma was achieved with a sensitivity and specificity of 97.22% and 100%, respectively. Significant correlation was found between the mitotic/ki-67 indexes and rCBV values when data for high- and low-grade tumours was combined.

CONCLUSION

DCE-MRI performed with a single dose of contrast medium is as effective as a protocol with a double-dose of contrast medium for glioma grading using 3 T MRI and could be added to the routine evaluation protocol of brain tumours.

Cupriavidus pauculus (Ralstonia paucula) concomitant meningitis and septicemia in a neonate: first case report from India

Ralstonia paucula (formerly classified as CDC (Centre for Disease Control) group IVc-2, Wautersia paucula; recently renamed as Cupriavidus pauculus) is an environmental Gram-negative bacillus isolated from water sources and can cause serious human infections. Patients recover bacteriologically indicating low virulence. A total of 32 cases have been reported world-wide, but no isolation has ever been reported from cerebrospinal fluid or in India. The first case of R. paucula meningitis and septicemia is being reported here along with the brief summary of cases reported world-wide.

In vitro activity of bioactive extracts from rare actinomycetes against multi-drug resistant Streptococcus pneumoniae

AIMS

In this study, we investigated the in vitro potential of the bioactive extracts from five putatively novel species of actinomycetes isolated from the Indian hot desert against multi-drug resistant (MDR) Streptococcus pneumoniae.

METHODS AND RESULTS

The antimicrobial activity of 10 different extracts was evaluated against S. pneumoniae strains with, erm(B) and mef(E) genes as well as fluoroquinolone-resistant (FQ(R) ) strains using the micro-broth dilution method. Of these 10 extracts, four exhibited good to excellent anti-S. pneumoniae activity with minimum inhibitory concentrations (MICs) ranging from 0·125 to 8 μg ml(-1) . The time-kill kinetics study showed that these extracts killed the pathogens in 2-8 h. In vitro cell-free transcription/translation of luciferase gene using S30 bacterial extract and TNT mammalian ribosome indicated that they inhibited bacterial ribosomes at much lower concentrations than those required to inhibit the mammalian ribosomes.

CONCLUSIONS

This study demonstrates that these are potent concentration-dependent bactericidal metabolites with 16-fold higher in vitro activity than levofloxacin against MDR S. pneumoniae.

SIGNIFICANCE AND IMPACT OF THE STUDY

Metabolites from actinomycetes can be excellent inhibitors of MDR S. pneumoniae. Considering the in vitro efficacy of these crude extracts against S. pneumoniae MDR spp., once purified these can be used against streptococcal pathogens causing community-acquired pneumonia.

Intracellular ions in salt-sensitive essential hypertension: possible role of calcium-regulating hormones

To study the blood pressure, ionic, and hormonal responses to chronic dietary salt loading, we measured RBC pHi, Mgi, Nai, and Cai, and compared these with serum levels of Ca-io, 1,25-D, and free levels of PHF in salt-sensitive and salt-insensitive essential hypertension subjects on low and high (200 mEq/day less than UNaV less than 50 mEq/day) dietary salt intakes. As a group, salt loading significantly increased diastolic blood pressure (7.6 +/- /3%), Nai (25.5 +/- /8%) and Cai (27.0 +/- /11%), while Mgi (-14.2 +/- 7%) and pHi (-0.03 +/- /0.01 pH units) fell. Significant changes in pHi, Cai, and Mgi occurred only in SS individuals, who also exhibited elevated levels of 1,25-D and of PHF in association with suppression of Ca-io. Altogether, the pressor response to salt was inversely related to the basal pHi (p less than 0.001), and to the degree of salt-induced suppression of Ca-io (p less than 0.001) and Mgi (p less than 0.001), while being directly related to the basal PHF (p less than 0.001) and to the salt-induced stimulation of 1,25-D (p less than 0.005). We hypothesize that elevated levels of 1,25-D and PHF coordinately shift intracellular cation levels and stimulate cellular calcium uptake from the extracellular space. As such, these calcium-regulating hormones may be responsible, at least in part, for salt-sensitive hypertension.

Hypoxia-Induced Inflammatory Chemokines in Subjects with a History of High-Altitude Pulmonary Edema

High altitude hypoxia is known to induce an inflammatory response in immune cells. Hypoxia induced inflammatory chemokines may contribute to the development of high altitude pulmonary edema (HAPE) by causing damage to the lung endothelial cells and thereby capillary leakage. In the present study, we were interested to know whether chronic inflammation may contribute to HAPE susceptibility. We examined the serum levels of macrophage inflammatory protein-1α (MIP-1α), monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 in group (1) HAPE Susceptible subjects (n = 20) who had past history of HAPE and group (2) Control (n = 18) consist of subjects who had stayed at high altitude for 2 years without any history of HAPE. The data obtained confirmed that circulating MCP-1, MIP-1α were significantly upregulated in HAPE-S individuals as compared to the controls suggestive of chronic inflammation. However, it is not certain whether chronic inflammation is cause or consequence of previous episode of HAPE. The moderate systemic increase of these inflammatory markers may reflect considerable local inflammation. The existence of enhanced level of inflammatory chemokines found in this study support the hypothesis that subjects with past history of HAPE have higher baseline chronic inflammation which may contribute to HAPE susceptibility.

Mature cystic retroperitoneal teratoma with well differentiated renal elements: relation to spinal dysraphism

Retroperitoneum is a relatively uncommon site for pediatric teratomas. Rarely, such tumors can have an intraspinal extension and few cases of retroperitoneal teratomas associated with spinal dysraphism have been reported. Teratomas consist of tissues arising from all three embryonic layers. However, mature renal tissues in the form of glomeruli and tubules are sparingly found in teratomas. A 15-day-old female presented with spina bifida occulta and on evaluation a cystic presacral mass was detected. Intraoperatively the cyst was found densely adherent to the hemivertebrae but not entering the spinal canal. Histopathological examination confirmed a mature cystic teratoma but also demonstrated presence of mature renal elements in the cyst wall. The teratomas lying in proximity to spine and associated with spinal dysraphism are likely to contain mature renal tissues or even nephroblastic elements. It supports the dysembryogenic model of origin of intradural teratomas from native progenitor cells rather than aberrantly migrated germ cells.

Ultrathin films of TiO2 nanoparticles at interfaces

The properties of a material change remarkably as a result of the scaling dimensions. The Langmuir-Blodgett (LB) film deposition technique is known to offer precise control over the film thickness and the interparticle separation. To form a well-ordered LB film, it is essential to form a stable Langmuir film at the air-water interface. Here, we report our studies on ultrathin films of TiO2 nanoparticles at air-water and air-solid interfaces. The Langmuir film of TiO2 nanoparticles at the air-water interface was found to be very stable, and it exhibits loose-packing and close-packing phases. The LB films were transferred onto solid substrates for characterization and application. The surface morphology of the LB film was obtained by a field emission scanning electron microscope. The optical and electronic properties of the LB films of TiO2 nanoparticles were studied using UV-vis spectroscopy and current-voltage measurements, respectively. The LB film of TiO2 nanoparticles was employed for ethanol gas sensing, and the sensing performance was compared to that of bulk material. Because of the enormous gain in the surface to volume ratio and the increase in crystalline defect density in the ultrathin LB film of TiO2 nanoparticles, the LB film is found to be a potential functional layer for ethanol sensing as compared to the bulk material.

What a practitioner needs to know about celiac disease?

Celiac disease (CD) is an immune-mediated systemic disorder elicited by gluten and related prolamines in genetically susceptible individuals and is characterized by the presence of a variable combination of gluten-dependent clinical manifestations, CD-specific antibodies, HLA-DQ2 or HLA-DQ8 haplotypes and enteropathy. CD is triggered by wheat gluten and related prolamines in barley and rye. Worldwide, the disease affects approximately 1 % of the general population. Clinical features of CD vary considerably. Intestinal symptoms are more common in young children. In older children extra intestinal manifestations affecting almost all organs are seen. IgA tTG antibody, upper GI endoscopy with histological analysis of multiple biopsies of the duodenum and in selected cases HLA DQ2 and DQ8 positivity and endomysial antibodies (EMA) are needed for diagnosis. Currently, the only treatment for CD is a life-long gluten-free diet (GFD). Strict avoidance of wheat, rye, barley and their derivatives will result in intestinal healing and relief of symptoms for the majority of individuals with CD. The GFD is simple in principle, however, completely eliminating all foods and ingredients containing wheat, rye, barley, and most commercial oats can be very challenging. Newly diagnosed CD children should undergo testing and treatment for micronutrient deficiencies specially iron, folic acid, vitamin D, and vitamin B12. Long-term monitoring and follow up of patients with CD is necessary.

HIV-1 subtype influences susceptibility and response to monotherapy with the protease inhibitor lopinavir/ritonavir

OBJECTIVE

PI susceptibility results from a complex interplay between protease and Gag proteins, with Gag showing wide variation across HIV-1 subtypes. We explored the impact of pre-treatment susceptibility on the outcome of lopinavir/ritonavir monotherapy.

METHODS

Treatment-naive individuals who experienced lopinavir/ritonavir monotherapy failure from the MONARK study were matched (by subtype, viral load and baseline CD4 count) with those who achieved virological response ('successes'). Successes were defined by viral load <400 copies/mL after week 24 and <50 copies/mL from week 48 to week 96. Full-length Gag-protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with susceptibility expressed as fold change (FC) relative to a subtype B reference strain.

RESULTS

Baseline lopinavir susceptibility was lower in viral failures compared with viral successes, but the differences were not statistically significant (median lopinavir susceptibility: 4.4 versus 8.5, respectively, P = 0.17). Among CRF02_AG/G patients, there was a significant difference in lopinavir susceptibility between the two groups (7.1 versus 10.4, P = 0.047), while in subtype B the difference was not significant (2.7 versus 3.4, P = 0.13). Subtype CRF02_AG/G viruses had a median lopinavir FC of 8.7 compared with 3.1 for subtype B (P = 0.001).

CONCLUSIONS

We report an association between reduced PI susceptibility (using full-length Gag-protease sequences) at baseline and subsequent virological failure on lopinavir/ritonavir monotherapy in antiretroviral-naive patients harbouring subtype CRF02_AG/G viruses. We speculate that this may be important in the context of suboptimal adherence in determining viral failure.

Metabolite pattern ofCysticercus cellulosaemetacestode from different predilection sites of swine using proton magnetic resonance spectroscopy

Cysticercosis due to Taenia solium is one of the most common public health problems in various regions of the world. We have performed prolon magnetic resonance spectroscopy (1H MRS) experiments of the fluid aspirated from cysticerci excised from skeletal muscle (n = 16) and brain (n = 9) of infected swine to compare the metabolite pattern of cysticerci in different predilection sites. Perchloric acid extract of cysticercus cysts excised from skeletal muscles (n = 16) was also prepared to ascertain water-soluble, low molecular weight metabolites using 1H MRS. Absolute quantification and statistical analysis of different metabolites was done to look for any significant differences in different locations of cysts. The metabolite pattern of cysticerci was found to be similar in the various predilection sites. Metabolites observed were leucine, valine, alanine, lysine, glycine, lipid contents, lactate, glutamate, acetate, succinate, creatine, choline, and glucose. Concentration of creatine in cysticercus fluid of cysts removed from the muscle was found to be significantly higher (p = 0.001) than the cysts located in the brain. We conclude that the metabolite pattern in the cysticerci is not influenced by the surrounding tissue location; however concentration of certain metabolites may depend upon the tissue location.

Effect of blanching on thin layer drying kinetics of aonla (Emblica officinalis) shreds

The effect of hot water blanching treatment on thin layer drying kinetics of aonla shreds was studied at drying air temperatures of 50, 55 and 60 °C with the air velocity of 1.2 m/s. The drying time decreased with the increase in air temperature and blanching. The drying process was observed in falling rate. Drying after blanching reduced the vitamin C content of aonla shreds by 69.36% whereas it decreased by 27.78% in unblanched shreds. Eight commonly used mathematical models were evaluated to predict the drying behavior of aonla shreds. The Midilli model described the drying behaviour of unblanched aonla shreds at all temperatures better than other models whereas two-term model described the drying kinetics of blanched aonla shreds satisfactorily. The effective diffusivities of the unblanched and blanched aonla shreds were determined using Fick's law of diffusion. The activation energy was found to be 47.21 kJ/mol for unblanched and 43.98 kJ/mol for blanched aonla shreds.

Impact of smoking on microalbuminuria and urinary albumin creatinine ratio in non-diabetic normotensive smokers

Smoking is associated with an excessive morbidity and mortality from a variety of diseases. The aim of this study was to find out the effects of smoking on renal function study in non-diabetic, normotensive subjects. A community-based, prospective, cross-sectional cohort study was conducted on 120 subjects; 80 (66.66%) were smokers and 40 (33.33%) age matched non-smokers; with age range of 30 to 70 years. Measurement of fasting sugar, urea, creatinine, lipids and one time screening of urinary albumin and urinary creatinine was done. Smokers had significantly higher urinary albumin and albumin creatinine ratio (ACR) (52.84 ± 46.42 mg/L, 93.98 ± 78.68 μg/mg) than non-smokers (19.25 ± 7.77 mg/L, 18.99 ± 6.65 μg/mg), respectively (P =< 0.001, P =< 0.001). Microalbuminuria and urinary ACR level were directly related to the amount of smoking (pack-years). Among smokers, 73 (91.25%) had microalbuminuria (>20 mg/L) and 64 (80%) had increased urinary ACR (>30 μg/mg). Smoker had significantly lower high-density lipoprotein level (36.66 ± 10.28 mg/dl) compared to non-smokers (41.22 ± 11.72 mg/dl) (P = 0.031). Urea, creatinine, creatinine clearance, total cholesterol, low density lipoprotein, triglyceride levels were comparable (p = NS). In conclusion, smokers have a 4-fold higher prevalence of microalbuminuria than non-smokers.

Efficacy of Spodoptera litura multiple nucleopolyhedrovirus after serial passage through the homologous insect larval host

An originally isolated baculovirus, Spodoptera litura multiple nucleopolyhedrovirus (SpltMNPV) was serially passed through the S. litura larvae for upto four generations to determine the mean number of occlusion bodies (OBs) harvested per larva and their efficacy in terms of infectivity, feeding cessation and speed of kill of host larvae. The results revealed that the mean number of OBs harvested per larva increased significantly with increase in the dose of SpltMNPV at each passage and the yield was significantly lower in original stock wild-type SpltMNPV (P0) as compared to serially passed SpltMNPV (P1, P2, P3 and P4). Laboratory bioassays indicate that median lethal doses (LD50), median times to feeding cessation (FT50) and median survival times (ST50) of P0, P1, P2, P3 and P4 were significantly different from each other. The OBs of each passage when tested for their cross-infectivity against Spodoptera exigua and Spilarctia obliqua revealed significant reduction in their mortality. These results indicate that serially passed SpltMNPV is more host specific and more effective biocontrol agent than the original stock wild-type virus and can be adopted for mass production as a viral pesticide for control of the S. litura.

Impact of human immunodeficiency virus and CD4 count on tuberculosis diagnosis: analysis of city-wide data from Cape Town, South Africa

BACKGROUND

The impact of human immunodeficiency virus (HIV) infection and CD4 count on the diagnosis of tuberculosis (TB) at population level is incompletely defined.

OBJECTIVE

To determine how HIV infection and CD4 count affect disease site, sputum smear status and overall rate of laboratory confirmation (sputum smear microscopy or culture) of TB cases under routine programme conditions.

DESIGN

Retrospective analysis of the 2009 electronic TB register for Cape Town, South Africa.

RESULTS

Of 29,478 TB cases notified in 2009, HIV status was known for 25,744 (87.3%) cases, of whom 13,237 (51.4%) were HIV-positive. Of these, 61.2% had CD4 cell counts of <200 cells/μl and 82.7% had counts of <350 cells/μl. Laboratory confirmation of TB (by smear or culture) was obtained less frequently in HIV-infected than non-HIV-infected adult cases (53.9% vs. 74.3%, P< 0.001). HIV infection was associated with a higher proportion of sputum smear-negative and extra-pulmonary TB and lower grades of sputum smear positivity even among those with CD4 counts of ≥ 500 cells/μl. However, the relationship between the proportion of smear-positive cases and CD4 count was non-linear.

CONCLUSION

Much TB is not laboratory-confirmed in this setting despite good laboratory services. HIV-associated TB is more difficult to diagnose even at high CD4 cell counts of >500 cells/μl, suggesting early impact after HIV seroconversion.

Mapping of glycine distributions in gliomas

BACKGROUND AND PURPOSE

Increased glycine concentration in the brain is associated with altered metabolism in cancer and can be detected by using in vivo MR spectroscopy. This has been proposed as a marker for grade IV gliomas; however, little is known about the potential significance and frequency of in vivo glycine observation. The purpose of this study was to examine the rate of occurrence and spatial distribution of glycine observation with respect to other MR imaging parameters.

MATERIALS AND METHODS

Data from volumetric whole-brain MR spectroscopic imaging of 59 subjects with glioma were analyzed with glycine included in the spectral model. The associations of the signal amplitude and spatial distributions of glycine with findings from contrast-enhanced T1, perfusion, and diffusion MR imaging were then examined.

RESULTS

Glycine was detected in 24% of all studies, though with a wide range of signal amplitude and extent of the spatial distributions. While more commonly seen in grade IV tumors (42% of studies), relatively large concentrations were also detected in grade II and III gliomas. Coanalysis with other metabolites indicated a strong association with choline and that glycine was frequently seen to be overlapping with, and adjacent to, areas of high lactate concentration. Increased glycine was always associated with contrast enhancement and areas of increased cerebral blood flow, but without any clear association with other image parameters.

CONCLUSIONS

Detection of increased glycine in gliomas appears to identify a subgroup of tumors and areas of increased proliferation.

Toxic shock syndrome following inguinal hernia repair: a rare condition

A 25-year-old man developed fulminant multisystem failure 28 hours after elective repair of an inguinal hernia. Toxic shock syndrome (TSS) was diagnosed. The patient recovered fully with supportive care in ICU, antibiotics, and IV human immunoglobin . To the best of our knowledge, only one case of TSS following inguinal hernia repair have ever been previously published. Journal of College of Medical Sciences-Nepal, 2013, Vol-9, No-2, 57-59 DOI: http://dx.doi.org/10.3126/jcmsn.v9i2.9689

MicroRNA mediated regulation of metal toxicity in plants: present status and future perspectives

The human population is increasing at an alarming rate, whereas heavy metals (HMs) pollution is mounting serious environmental problem, which could lead to serious concern about the future sufficiency of global food production. Some HMs such as Mn, Cu, and Fe, at lower concentration serves as an essential vital component of plant cell as they are crucial in various enzyme catalyzed biochemical reactions. At higher concentration, a vast variety of HMs such as Mn, Cu, Cd, Fe, Hg, Al and As, impose toxic reaction in the plant system which greatly affect the crop yield. Recently, microRNAs (miRNAs) that are small class of non-coding riboregulator have emerged as central regulator of numerous abiotic stresses including HMs. Increasing reports indicate that plants have evolved specialized inbuilt mechanism viz. signal transduction, translocation and sequestration to counteract the toxic response of HMs. Combining computational and wet laboratory approaches have produced sufficient evidences concerning active involvement of miRNAs during HMs toxicity response by regulating various transcription factors and protein coding genes involved in plant growth and development. However, the direct role of miRNA in controlling various signaling molecules, transporters and chelating agents of HM metabolism is poorly understood. This review focuses on the latest progress made in the area of direct involvement of miRNAs in signaling, translocation and sequestration as well as recently added miRNAs in response to different HMs in plants.

A comparison of infectivity between polyhedra of the Spodoptera litura multiple nucleopolyhedrovirus before and after passage through the gut of the stink bug, Eocanthecona furcellata

Infectivity of polyhedra of Spodoptera litura multiple nucleopolyhedrovirus before and after passage through the gut of the predatory stink bug, Eocanthecona furcellata Wolff (Hemiptera: Pentatomidae) was compared through field bioassay studies. Three sets of E. furcellata were used for bioassays and these were allowed to feed on a single meal of five third instar Oriental leaf worm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), that were infected with polyhedra before passage, after passage, and healthy (control) larvae 1 day prior to the trial. The predators were subsequently released on cabbage plants that were infested with 100 healthy S. litura larvae. The median lethal dose (LD50) and survival time (ST50) values before and after passage through the gut were not significantly different. Additional mortality due to virus infection increased 13- 17% before and after treatments but within these treatments the mortality did not vary significantly. It was concluded that E. furcellata disseminated the virus through their feces into the ecosystem and infectivity of the SpltMNPV was not altered after passage through the gut of the predator.

An Evaluation of the Resonance Frequency Analysis Device: Examiner Reliability and Repeatability of Readings

Initial stability at the placement and development of osseointegration are 2 major issues for implant survival. Many of the presently used noninvasive methods of evaluating the stability of implants are highly subjective. The resonance frequency analysis (RFA) device is claimed to offer a more objective means to assess implant stability. Limited information is available on the interexaminer reliability and repeatability of the RFA device, used to measure implant stability. Two blind in vivo studies were conducted using 50 implant cases. In the first clinical study, 3 investigators took implant stability quotient (ISQ) readings for each implant to check the interoperator reliability for the RFA device. In the second clinical study, implant stability was measured by the same operator using the RFA device for each implant 3 times on the same day with a 15-minute interval, to check the repeatability of the RFA device. Within the limitations of this study, the RFA device demonstrated a high degree of interoperator reliability and repeatability.

DTI correlates of cognition in conventional MRI of normal-appearing brain in patients with clinical features of subacute combined degeneration and biochemically proven vitamin B(12) deficiency

BACKGROUND AND PURPOSE

Vitamin B12 deficiency may cause neural injury that results in cognitive deficits. The main purpose of our study was to evaluate morphometric and microstructural changes in the brain and relate them to cognition in subacute combined degeneration of the spinal cord and patients with biochemically deficient vitamin B12.

MATERIALS AND METHODS

Fifty-one patients were recruited and underwent nerve-conduction velocity tests and routine hematologic examinations. Serum vitamin B12 and homocystine levels were also measured. All patients and 46 age- and sex-matched controls underwent cervical spine and brain MR imaging along with cognition tests. MR imaging included conventional scans and DTI. Voxel-based morphometry was performed for determining the WM and GM volumes, based on T1-weighted images. DTI measures that included fractional anisotropy, ADC, radial diffusivity, and axial diffusivity were determined by using tract-based statistics.

RESULTS

None of the patients showed any abnormality on conventional MR imaging. No significant changes in GM and WM volumes were observed in patients compared with controls. Significant reductions in the fractional anisotropy and an increase in ADC and radial diffusivity values were observed in multiple brain regions in patients compared with controls. These changes were confirmed on the region-of-interest analysis. Neuropsychological scores were significantly different in patients compared with controls and showed significant correlation with fractional anisotropy and radial diffusivity in a few brain regions.

CONCLUSIONS

Microstructural changes are seen in WM regions on DTI in patients with vitamin B12 deficiency and correlate with cognition scores. DTI can be used for objective assessment of microstructural changes in the brain in vitamin B12 deficiency.