<Emphasis Type="Italic">Rhizobium</Emphasis> Mutant Deficient in Mineral Phosphate Solubilization Activity Shows Reduced Nodulation and Plant Growth in Green Gram

The aim of the present study was to understand the mineral phosphate solubilization (MPS) in Rhizobium sp. MR-54 (MPS⁺) by using forward genetic approach and its effect on nodulation as well as nitrogen accumulation on green gram. Tn5 mutants (MPS^?) were generated from the MPS⁺ strain by Tn5 mutagenesis. Screening 1,603 colonies of MR-54::Tn5 resulted in identification of those mutants which failed to show any solubilization zone up to 72 h after incubation on Tri-calcium phosphate medium (TCP). pH drops and Pi release were highly correlated up to 15 days after incubation in TCP broth. Gluconic acid was detected in the culture supernatants of MPS⁺ isolates through thin layer chromatography indicating the presence of direct oxidation pathway in MR-54 strain. Detailed characterization of mutants was carried out for related properties like colony morphology, Pi release and pH change in TCP broth, organic acid production, surface characteristics and plant growth promoting ability etc. Mutants deficient in MPS showed reduced nodulation and nitrogen accumulation in green gram under green house conditions in leonard jar apparatus over the wild strain indicating the MPS by Rhizobium being involved in nodulation, nitrogen accumulation and plant growth.     

Salivary gland tumors: a single institution experience in India

Between 1991 and 2006, 684 cases of salivary gland tumours were analysed retrospectively, of which 422 (62%) were benign and 262 (38%) malignant. Sixty-one percent of tumours were in the parotid gland, 22% in the minor salivary glands, and 17% in the submandibular glands. The most common benign tumour was pleomorphic adenoma (86%), and the most common malignant tumours were adenoid cystic carcinoma (25%) and mucoepidermoid carcinoma (18%). Among the minor salivary gland tumours, most were seen in the palate (68%).We analyse the incidence and distribution of all types of salivary gland tumours in an Indian series, and provide data for comparison with other epidemiological studies from different geographical sites and races. Demographic data from these studies should help us to a better understanding of the biological and clinical characteristics of the disease.     

Sex differences in the inflammatory response and inflammation-induced vascular dysfunction

Background

Premenopausal women have a lower incidence of cardiovascular disease, although the exact mechanism underlying this protection is unclear. Both systemic and localised inflammation have a crucial role in the progression of cardiovascular disease, and much preclinical and observational data in human beings suggest that differences in inflammation between the sexes exist. We investigated whether inflammation, and which components of the inflammatory response, might be altered in women compared with men.

Immunosenescence of human NK cells: effects on tumor target recognition, lethal hit and interferon sensitivity.

Previous results from this laboratory have shown the preservation of non-MHC-restricted, constitutive oncolytic activity of human peripheral blood NK cells in the elderly as assessed by the chromium release assay which quantitates the lytic endpoint at the cell population level. We have now addressed this senescence-related change at single-cell level using 101 blood samples. Both the efficiency of the initial tumor target binding step i.e., recognition of K562, the NK-sensitive erythroleukemia cell line, as well as the ability of NK cells to deliver lethal hit are highly conserved during healthy aging. In fact, the elderly exhibit a statistically significant, moderately higher frequency of active killers among circulating lymphocytes. Analyzed in another way, a majority of "high NK responders" were found to be older donors, while none in the "low NK responders" group were > 70 years old. Gamma interferon, a gene product as well as an autocrine activator of NK cells, is effective in converting non-lytic "pre-NK" cells to active killers at single-cell level. This in vitro cytokine sensitivity of NK cells is unaltered during immune senescence. The intactness of the NK cell's capacity to be modulated may be vital in both tumor resistance and host viral defenses of aged humans.     

Simulating Dual-Energy X-Ray Absorptiometry in CT Using Deep-Learning Segmentation Cascade

PurposeOsteoporosis is an underdiagnosed condition despite effective screening modalities. Dual-energy x-ray absorptiometry (DEXA) screening, although recommended in clinical guidelines, remains markedly underutilized. In contrast to DEXA, CT utilization is high and presents a valuable data source for opportunistic osteoporosis screening. The purpose of this study was to describe a method to simulate lumbar DEXA scores from routinely acquired CT studies using a machine-learning algorithm.MethodsBetween January 2010 and September 2014, 610 CT studies of the abdomen and pelvis were used to develop spinal column and L1 to L4 multiclass segmentation. DEXA simulation training and validation used 1,843 pairs of CT studies accompanied by DEXA results obtained within a 6-month interval from the same individual. Machine learning–based regression was used to determine correlation between calculated grade (on the basis of vertebrae L1-L4) and DEXA t score.ResultsAnalysis of the t score equivalent, generated by the algorithm, revealed true positives in 1,144 patients, false positives in 92 patients, true negatives in 245 patients, and false negatives in 212 patients, resulting in an accuracy of 82%. Sensitivity for the detection of osteoporosis or osteopenia was 84.4% (95% confidence interval, 82.3%-86.2%), and specificity was 72.7% (95% confidence interval, 67.7%-77.2%).ConclusionsThe presented algorithm can identify osteoporosis and osteopenia with a high degree of accuracy (82%) and a small proportion of false positives. Efforts to cull greater information using machine-learning algorithms from pre-existing data have the potential to have a marked impact on population health efforts such as bone mineral density screening for osteoporosis, in which gaps in screening currently exist.     

Atrial flutter ablation in a case of diuretic resistant constrictive pericarditis

We present a 66 year old gentleman with constrictive pericarditis and persistent atrial flutter. Initial management with oral loop diuretics was successful until he developed persistent atrial flutter. Once in atrial flutter the patient developed progressive signs of right heart failure resistant to high dose intravenous loop diuretics. He was referred to a tertiary electrophysiology service where he underwent successful isthmus catheter ablation and reverted to sinus rhythm. His responsiveness to diuretics improved immediately. His symptoms improved and he was discharged 48 h later on oral diuretics. He remains well one month after discharge.This is the first reported case of symptomatic improvement in a patient with constrictive pericarditis and persistent atrial flutter with targeted treatment of the dysrhythmia. This offers a possible short-term palliation option in a group of patients where definitive surgical management carries too high a risk.