On the nature of magnetic state in the spinel Co2SnO4.

In the spinel Co2SnO4, coexistence of ferrimagnetic ordering below T(N) ≃ 41 K followed by a spin glass state below T(SG) ≃ 39 K was proposed recently based on the temperature dependence of magnetization M(T) data. Here new measurements of the temperature dependence of the specific heat C(P)(T), ac-susceptibilities χ'(T) and χ″(T) measured at frequencies between 0.51 and 1.2 kHz, and the hysteresis loop parameters (coercivity H(C)(T) and remanence M(R)(T)) in two differently prepared samples of Co2SnO4 are reported. The presence of the Co(2+) and Sn(4+) states is confirmed by x-ray photoelectron spectroscopy (XPS) yielding the structure: Co2SnO4 = [Co(2+)][Co(2+)Sn(4+)]O4. The data of C(P) versus T shows only an inflection near 39 K characteristic of spin-glass ordering. The analysis of the frequency dependence of ac-magnetic susceptibility data near 39 K using the Vogel-Fulcher law and the power-law of the critical slowing-down suggests the presence of spin clusters in the system which is close to a spin-glass state. With a decrease in temperature below 39 K, the temperature dependence of the coercivity H(C) and remanence M(R) for the zero-field cooled samples show both H(C) and M(R) reaching their peak magnitudes near 25 K, then decreasing with decreasing T and becoming negligible below 15 K. The plot of C(P)/T versus T also yields a weak inflection near 15 K. This temperature dependence of H(C) and remanence M(R) is likely associated with the different magnitudes of the magnetic moments of Co(2+) ions on the 'A' and 'B' sites and their different temperature dependence.

Genome-wide mapping of Myc binding and gene regulation in serum-stimulated fibroblasts.

The transition from quiescence to proliferation is a key regulatory step that can be induced by serum stimulation in cultured fibroblasts. The transcription factor Myc is directly induced by serum mitogens and drives a secondary gene expression program that remains largely unknown. Using mRNA profiling, we identify close to 300 Myc-dependent serum response (MDSR) genes, which are induced by serum in a Myc-dependent manner in mouse fibroblasts. Mapping of genomic Myc-binding sites by ChIP-seq technology revealed that most MDSR genes were directly targeted by Myc, but represented a minor fraction (5.5%) of all Myc-bound promoters (which were 22.4% of all promoters). Other target loci were either induced by serum in a Myc-independent manner, were not significantly regulated or were negatively regulated. MDSR gene products were involved in a variety of processes, including nucleotide biosynthesis, ribosome biogenesis, DNA replication and RNA control. Of the 29 MDSR genes targeted by RNA interference, three showed a requirement for cell-cycle entry upon serum stimulation and 11 for long-term proliferation and/or survival. Hence, proper coordination of key regulatory and biosynthetic pathways following mitogenic stimulation relies upon the concerted regulation of multiple Myc-dependent genes.

DREAM2 challenge.

In the Dialogue for Reverse Engineering Assessments and Methods Conference (DREAM2) BCL6 target identification challenge, we were given a list of 200 genes and tasked to identify which ones are the true targets of BCL6 using an independent panel of gene-expression data. Initial efforts using conventional motif-scanning approaches to find BCL6 binding sites in the promoters of the 200 genes as a means of identifying BCL6 true targets proved unsuccessful. Instead, we performed a large-scale comparative study of multiple expression data under different conditions. Specifically, we employed a supervised learning approach that learns and models the expression patterns under different conditions and controls from a training collection of known BCL6 targets and randomly chosen decoys. Genes in the given list whose expression matches well with that of the training set of known BCL6 targets are more likely to be BCL6 targets. Using this approach, we are able to identify BCL6 targets with high accuracy, making us joint best performers of the challenge.

Voided urinary cytology in bladder cancer: is it time to review the indications?

OBJECTIVES: The sensitivity of voided urinary cytology has been reported as very low. In this study, we investigated the sensitivity and clinical utility of voided urinary cytology in the detection of various grades and stages of transitional cell carcinoma (TCC) of the bladder compared with the urinary nuclear matrix protein-22 (NMP-22) qualitative assay. METHODS: From March 2004 to April 2006, all patients with TCC of the bladder receiving follow-up care and those presenting with gross hematuria were enrolled in this prospective study. These patients underwent urinary cytologic examination and NMP-22 qualitative assay. The diagnosis, determined from the cystoscopy findings and biopsy findings of the suspicious lesion, was accepted as the reference standard. RESULTS: A total of 196 patients were enrolled in this study, of whom 127 patients had previously been diagnosed with bladder TCC and 69 were presenting for investigation of gross hematuria. A total of 52 cases of bladder TCC were diagnosed. The overall sensitivity of voided urine cytology and NMP-22 assay was 21.1% and 67.3%, respectively (P <0.001). The sensitivity of urinary cytology and urinary NMP-22 for well-differentiated tumors was 9.5% and 52.4%, respectively, and was 18.1% and 77.3%, respectively (P <0.001), in moderately differentiated tumors. The overall specificity of urinary cytology for TCC of the bladder was 98.6% and was greater than the specificity of NMP-22 (80.5%). CONCLUSIONS: The results of our study suggest that urinary cytology has a very low sensitivity and can be omitted in favor of NMP-22 in the follow-up of low-grade superficial bladder TCC.

Intravesical Explosion during Transurethral Resection of Prostate - a reminder.

Intravesical explosion during transurethral resection of the prostate (TURP) is an extremely rare but dreaded complication and results in rupture of the bladder. It is believed that intravesical explosion occurs due to formation of explosive gases in the bladder during TURP and its admixture with air. A case of intravesical explosion during TURP resulting in bladder rupture at our institution is described. Though the management of this catastrophe is relatively straightforward, it has the potential for dire consequences. We emphasize that, despite its rare occurrence, it is preventable and suggest measures to avoid it.

Dispelling inhibition for laparoscopic surgery in younger children with Cushing's syndrome. Case report and literature review.

Laparoscopic adrenalectomy (LA) is now the gold standard for the treatment of small, benign adrenal tumors in adults. In Cushing's syndrome (CS), LA is difficult and seldom done, especially in younger children. A 6-year-old girl was diagnosed with CS due to a juxtaadrenal tumor. She underwent LA and made an uneventful recovery. The histopathology was reported as paraganglioma which is a very rare cause of CS. LA is seldom done in younger children with CS owing to extreme obesity, abundant perinephric fat and a high incidence of pre- and postoperative complications.

Assessing the efficiency of extracorporeal shockwave lithotripsy for stones in renal units with impaired function: a prospective controlled study.

The objective was to determine the efficiency of extracorporeal shockwave lithotripsy (ESWL) in clearing stones from renal units with impaired function. Thirty-five patients with poorly functioning kidneys determined by intravenous urogram and 99mtechnetium diethylene triamine pentacetic acid renal dynamic scan underwent ESWL. Stone clearance was assessed at 3 months and compared with that in normally functioning kidneys. The study group was divided into two subgroups. Those with split glomerular filtration rate (GFR) of the concerned kidney between 10 and 20 ml/min were in group 1. Group 2 consisted of patients with split GFR between 20 and 30 ml/min. A control group (group 3) was formed from patients with urolithiasis and normally functioning kidneys. The overall retreatment rate was 84.4%. The overall stone clearance rate in the study group was 34.2% while it was 57.7% in the control group. The stone clearance rate in group 2 was 40%. The difference in stone clearance rate between the study and control groups was statistically significant (P=0.023) but that between group 2 and the control group was not (P=0.159). The incidence of steinstrasse between the study group 2 and control group was not statistically significant (P=0.408). The clearance rate for ureteral stones was comparable in all the three groups. The stone-free rate and rate of steinstrasse for renal stones in kidneys with moderately impaired function were comparable to normally functioning kidneys. However, kidneys with severely impaired function had poor results. The clearance rate for ureteral stones was not influenced by the impairment of renal function.

A Comparative Study of Laparoscopic with Conventional Open Donor Nephrectomy in Renal Transplantation.

BACKGROUND: Laparoscopic donor nephrectomy (LDN) has been gaining popularity among kidney donors. There have been concerns about the safety and efficacy of the procedure as compared to open donor nephrectomy (ODN). We compare our results on LDN with ODN. METHODS: We retrospectively analysed our data of LDN and ODN. Duration of surgery, blood loss, period of hospitalisation, per oral intake and analgesic requirements. RESULT: 22 LDNs were done, the operation time ranged from 220-300 minutes, and blood loss from 100-150ml. In the first 10 laparoscopic operations four cases required conversion to open surgical dissection. Only one case was converted to open surgery in the subsequent 12 laparoscopic cases. Oral intake was started on the first postoperative day. Analgesic requirement in laparoscopy cases was less. Patients were mobilised on the first day after surgery. Patients were discharged by seventh day. There was no significant difference in the functioning of the graft after revascularisation in the recipient. CONCLUSION: Laparoscopic donor nephrectomy is a safe and effective technique of donor nephrectomy.

Experience with marginal living related kidney donors: are they becoming routine or are there still any doubts?

OBJECTIVES: To analyze donor and recipient outcome of grafts from marginal kidney donors (ie, elderly or suffering from some anomaly). METHODS: We had 81 marginal donors from July 1996 to July 2004; 46 were older than 60 years, and 39 had renal or nonrenal anomaly. The donors and recipients were evaluated for morbidity, graft and recipient survival, and the number of rejection episodes. RESULTS: The mean (+/- standard deviation) age of elderly donors was 62.2 +/- 3.1 years. Follow-up ranged from 6 months to 50 months (mean 21.15 +/- 0.9 months). Actuarial 1-year and 3-year graft survival rates were 95% and 81%, respectively. Twenty-six percent of recipients maintained serum creatinine levels less than 1.4 mg/dL. The mean age of hypertensive donors was 46.2 years, and blood pressure was controlled with one drug. Serum creatinine levels in the recipients were less than 1.4 mg/dL in 10 and less than 2.5 mg/dL in the rest. Eleven percent of hypertensive donors required an increase in their antihypertensive medication. All donors showed a 15% to 20% increase in their glomerular filtration rate. Donors underwent simultaneous surgery when indicated. CONCLUSIONS: Criteria to reject donors need to be reviewed periodically. The elderly and donors with other anomalies are consistently showing acceptable results. Hypertensive donors require assessment with awake ambulatory blood pressure monitoring.

Prolactin signaling to pim-1 expression: a role for phosphatidylinositol 3-kinase.

Sublines of the lactogen-dependent, rat pre-T Nb2 lymphoma are useful as a model for the investigation of prolactin (PRL) signaling mechanisms, regulation of transcription of target genes, and the immunomodulatory and anti-apoptotic actions of the hormone in T lymphocytes. In the present study, coupling of various tyrosine, serine/threonine, and phospholipid kinase signaling mechanisms to PRL-stimulated Nb2-11 cell proliferation and expression of the protooncogene, pim-1, was investigated utilizing pharmacologic antagonists of a broad spectrum of tyrosine kinases (tyrphostin A25), and the specific enzymes, Jak2 (tyrphostin B42) and ZAP-70 (piceatannol), as well as mitogen-activated protein kinase (MAPK, PD98059), protein kinase C (PKC, calphostin C), and phosphatidylinositol 3-kinase (PI3-kinase, LY294002). Inhibition of each pathway attenuated PRL-stimulated Nb2-11 cell proliferation in a concentration-dependent manner. Blockade of MAPK was the least efficacious; it inhibited proliferation maximally by 60%. Northern blot analysis of pim-1 expression in antagonist-treated cells revealed that MAPK, Jak2 and PI3-kinase appeared to signal to initiation of pim-1 transcription; its expression was attenuated by each of the antagonists. In other experiments, PRL was shown to rapidly activate a downstream effector of PI3-kinase, Akt, and this effect was also blocked by LY294002. It is concluded that PRL-stimulated Nb2 cell proliferation requires participation of each of the signaling pathways investigated. Moreover, hormone-mediated expression of pim-1 appears to reflect signaling by MAPK, Jak2, and PI3-kinase.

Early development of emergency medicine in Chennai (Madras), India.

India is the second most populous country in the world, with a population approaching 1 billion people. The development of emergency medicine is still in its earliest stages because the Medical Council of India (MCI) does not yet recogonize the specialty. Recent developments may cause the MCI to reconsider specialty status for emergency medicine as an academic discipline.

Immunologic response to tetanus toxoid in geriatric patients.

STUDY OBJECTIVE: Tetanus antibody levels have been shown to be inadequate in 50% of patients older than 65 years. Although immunization recommendations have been made for this age group, the efficacy of this intervention has not been well documented. We sought to determine the difference in tetanus antibody levels after the administration of one tetanus toxoid immunization to geriatric patients without adequate titers. METHODS: Thirty-five patients older than 65 years at a large urban comprehensive care geriatric center who were documented to have inadequate tetanus antibody titers were each given one tetanus toxoid immunization. Repeat titers were obtained at least 2 months after the immunization with the use of enzyme-linked immunosorbent assay (Bindazyme kit; the Binding Site Corporation, Birmingham, England). We considered tetanus antibody levels greater than .17 IU/mL protective. RESULTS: The mean age was 79.4 years; 30 of 35 (86%) were female. Repeat tetanus antibody titers were obtained an average of 123 days (range, 63 to 204 days) after immunization with tetanus toxoid. The mean preimmunization antibody titer was .1 IU/mL (range, .04 to .16 IU/mL). After immunization, antibody titers increased a mean of .61 IU/mL (range, -.01 to 2.23 IU/mL; 95% confidence interval, .35 to .87 IU/mL). Thirty of the 35 patients who received a single injection of tetanus toxoid (86%) developed protective titers. We found no relationship between seroconversion and age, sex, or medical history; nor did we find a relationship between antibody level and time elapsed since immunization when repeat titers were obtained. CONCLUSION: Administration of one tetanus toxoid injection affords protective immunity in many geriatric patients.

Antibody protection to diphtheria in geriatric patients: need for ED compliance with immunization guidelines.

STUDY OBJECTIVE: Because 50% to 70% of geriatric patients have been shown to have nonproductive levels of tetanus antibodies, we postulated that this population might also have inadequate levels of diphtheria antibodies. Emergency physicians have the opportunity to immunize patients against tetanus and diphtheria. We sought to determine the seroprevalence of diphtheria antibodies in patients older than 65 years and to assess compliance with immunization guidelines in EDs. METHODS: Enzyme-linked immunosorbent assay for diphtheria antibodies was conducted in 58 outpatients of geriatric medical facility aged 65 years or older. We considered titers greater than .1 IU/mL protective. Eighteen ED personnel, ages 25 to 40 years, served as comparison subjects. The preparation used for immunization of injured patients--tetanus toxoid or tetanus and diphtheria toxoids adsorbed for adult use--was determined by means of a telephone survey of 64 New York City EDs. RESULTS: The mean age of our patients was 80 years (range, 65 to 95 years). Their mean diphtheria antibody titer was .17 IU/mL (range, .04 to .54 IU/mL). Thirty-three percent (19 of 58; 95% confidence interval [Cl], 21% to 54%) of patients had inadequate levels of diphtheria antibodies. We found no significant differences between protected and nonprotected patients with respect to age, sex, medical history, or military service. Patients with nonprotective levels of diphtheria antibodies were more likely to have inadequate tetanus antibody titers. Sixty-eight percent of patients without protection from diphtheria (13 of 19; 95% Cl, 48% to 88%) were also unprotected from tetanus, and 33% (13 of 39; 95% Cl, 19% to 47%) o those with adequate diphtheria antibodies had nonprotective levels of tetanus antibodies (P = .012). All 18 ED personnel had adequate diphtheria and tetanus antibodies. The telephone survey revealed that 30% (19 of 64) of EDs use only tetanus toxoid for immunization of injured patients. CONCLUSION: A significant percentage of geriatric patients have inadequate diphtheria antibodies. Emergency physicians must comply with immunization guidelines for injured patients to assure adequate protection from both tetanus and diphtheria.

Biochemical speciation of enterococci causing human infections.

As Enterococci are now coming up as important nosocomial pathogens, their speciation and antibiotic sensitivity testing is important. 120 isolates of Enterococci from various clinical samples were physiologically and biologically characterised. Speciation on the basis of recommended methods revealed 114(95%) as E. faecalis and 6(5%) as E. faecium. Antibiogram of the 120 isolates showed that 100(83.3%) were sensitive to Ampicillin. Combination of Penicillin and Gentamicin was more effective. E. faecium was more drug resistant.

Segmental enteritis: "enteritis necroticans". A clinicopathologic study.

Acute segmental enteritis, also called "enteritis necroticans" is characterized by nonocclusive intestinal ischemia in the absence of any precipitating cause. We studied 30 such patients over a 5.5-year period. All patients had acute abdominal symptoms requiring emergency laparotomy, and in only 30% was a preoperative diagnosis of segmental enteritis proposed. The jejunum alone (63.3%), or with the ileum (26.7%), was the most common site of necrotic patches (86.7%), frank gangrene (50.0%), free perforation (36.7%), and circumferential dusky lesions (30.0%). Twenty-eight patients required resection of the affected bowel. Specimen angiography in two cases showed normal mesenteric vasculature. In 12 patients, a detailed microbiological profile from peritoneal fluid, intestinal contents, and intestinal wall was performed, but Clostridium welchii was isolated from none. The resected intestinal specimens showed mucosal ulceration, submucosal edema, mixed inflammatory infiltrate, and patchy necrosis of the muscularis propria. The intramural vessels were patent in all cases. Wound-related complications occurred in 14, pulmonary complications in 14, renal failure in eight, and fecal fistulas in five; 23.3% died.

A boy with an anterior mediastinal mass.

A 12-year-old boy presented for biopsy of a large mediastinal mass. General anaesthesia precipitated immediate severe airway obstruction. This was overcome by the insertion of two microlaryngeal tubes, one into each main bronchus. The anaesthetic management of patients with an anterior mediastinal mass is discussed and the importance of pre-operative assessment stressed.

Failure of extradural blockade in obstetrics. A new hypothesis.

Three-thousand and eleven consecutive obstetric extradural blocks were evaluated retrospectively. The distance from the skin to the extradural space was correlated with the incidence of unilateral blockade. There was a significant correlation (P less than 0.001) between an increasing distance and increased incidence of unilateral block. We propose that this is because of the topography of the extradural space, and because of the deviation of the tip of the needle from the midline (when using a midline approach).