Fulminant amebic colitis: An unusual postoperative complication of intraabdominal malignancy

Amebiasis caused by protozoa Entamoeba histolytica (EH) is the third leading parasitic cause of human mortality. Although amebiasis is endemic in India, only about 10% of the infected individuals manifest disease. Clinical spectrum of amebiasis ranges from asymptomatic colonization to amebic colitis to hemorrhagic and fulminant colitis. Factors causing an invasive infection are not completely understood. Pathogen virulence, host immunity, and ability of the pathogen to evade host immune response play vital role in determining the disease course. Host factors such as immunocompromised states may make an individual susceptible to develop symptomatic infection. Malignancies usually result in chronic debilitation which may make the individual prone to develop invasive amebiasis with rapid progression. We report two cases of invasive amebiasis which developed a fulminant course in the immediate postoperative period after abdominal surgeries for visceral malignancies.

Occupancy detection in non-residential buildings – A survey and novel privacy preserved occupancy monitoring solution

Buildings use approximately 40% of global energy and are responsible for almost a third of the worldwide greenhouse gas emissions. They also utilise about 60% of the world’s electricity. In the last decade, stringent building regulations have led to significant improvements in the quality of the thermal characteristics of many building envelopes. However, similar considerations have not been paid to the number and activities of occupants in a building, which play an increasingly important role in energy consumption, optimisation processes, and indoor air quality. More than 50% of the energy consumption could be saved in Demand Controlled Ventilation (DCV) if accurate information about the number of occupants is readily available (Mysen et al., 2005). But due to privacy concerns, designing a precise occupancy sensing/counting system is a highly challenging task. While several studies count the number of occupants in rooms/zones for the optimisation of energy consumption, insufficient information is available on the comparison, analysis and pros and cons of these occupancy estimation techniques. This paper provides a review of occupancy measurement techniques and also discusses research trends and challenges. Additionally, a novel privacy preserved occupancy monitoring solution is also proposed in this paper. Security analyses of the proposed scheme reveal that the new occupancy monitoring system is privacy preserved compared to other traditional schemes.

The identification, assessment and management of difficult-to-treat depression: An international consensus statement

BACKGROUND

Many depressed patients are not able to achieve or sustain symptom remission despite serial treatment trials - often termed "treatment resistant depression". A broader, perhaps more empathic concept of "difficult-to-treat depression" (DTD) was considered.

METHODS

A consensus group discussed the definition, clinical recognition, assessment and management implications of the DTD heuristic.

RESULTS

The group proposed that DTD be defined as "depression that continues to cause significant burden despite usual treatment efforts". All depression management should include a thorough initial assessment. When DTD is recognized, a regular reassessment that employs a multi-dimensional framework to identify addressable barriers to successful treatment (including patient-, illness- and treatment-related factors) is advised, along with specific recommendations for addressing these factors. The emphasis of treatment, in the first instance, shifts from a goal of remission to optimal symptom control, daily psychosocial functional and quality of life, based on a patient-centred approach with shared decision-making to enhance the timely consideration of all treatment options (including pharmacotherapy, psychotherapy, neurostimulation, etc.) to optimize outcomes when sustained remission is elusive.

LIMITATIONS

The recommended definition and management of DTD is based largely on expert consensus. While DTD would seem to have clinical utility, its specificity and objectivity may be insufficient to define clinical populations for regulatory trial purposes, though DTD could define populations for service provision or phase 4 trials.

CONCLUSIONS

DTD provides a clinically useful conceptualization that implies a search for and remediation of specific patient-, illness- and treatment obstacles to optimizing outcomes of relevance to patients.

MSTO1 mutations cause mtDNA depletion, manifesting as muscular dystrophy with cerebellar involvement

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype–phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.

Should all acromioclavicular joint injections be performed under image guidance?

INTRODUCTION

Steroid and local anaesthetic injection to the acromioclavicular joint (ACJ) is a very common diagnostic and therapeutic procedure, which is often performed in the outpatient department. However, it can be difficult to localize this joint because of its small size, presence of osteophytes and variable morphology in the population. We performed a study to determine whether the use of an image intensifier (X-ray guidance), in theatre, improves the accuracy of this injection.

METHODS

This was a prospective study carried out between March 2014 and March 2015. The injections were performed by two senior orthopaedic surgeons. First, we clinically palpated the ACJ and marked the area over this point as A. Then, with the use of a needle and an image intensifier in a single plane, we identified the actual location of the ACJ and marked this point as B. We measured the distance between A and B in millimetres (mm) and determined the accuracy of the injections. Further analysis taking into account the ACJ capsular attachments was also performed.

RESULTS

In total, 45 patients and 50 injections were included in the study; five patients had repeated injections at different times. We found that only 12 injections (24%) were palpated to be correct with no discrepancies between A and B (95% confidence interval: 14-37%). For the remaining 38 injections (76%), the use of an image intensifier had significantly improved the accuracy of ACJ location ( p < 0.05). Taking the capsular attachments of the ACJ into consideration reduced the number of inaccurate injections to 27 (54%).

CONCLUSION

We recommend the use of an image intensifier (or ultrasound guidance) to accurately determine the location of the ACJ for steroid and local anaesthetic injections. This prevents an injection into the wrong place, which can lead to wrong diagnosis and/or suboptimal treatment.

Effect of vitamin D3 treatment on endothelial function in obese adolescents

BACKGROUND

Obesity in children is associated with vitamin D deficiency and endothelial dysfunction. It is not known if treatment with vitamin D improves endothelial function in obese adolescents.

OBJECTIVE

This study aimed to determine whether treatment with vitamin D3 improves endothelial function in obese adolescents.

METHODS

Nineteen obese adolescents, 13-18 years of age, with 25-hydroxy vitamin D (25[OH]D) levels <75 nmol L(-1) were treated with 100 000 IU vitamin D3 orally once a month for 3 months in an open-label, single-centre prospective trial. Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery at study entry and 1 month after the third dose of vitamin D3 . Biochemical parameters, including calcium, fasting lipids, glucose, insulin and high-sensitivity C-reactive protein, were also obtained.

RESULTS

Mean 25(OH)D levels increased from 55.9 ± 12.2 to 86.9 ± 16.7 nmol L(-1) (P < 0.01). There was no correlation between 25(OH)D levels and brachial artery FMD. The brachial artery FMD (%) did not change significantly following vitamin D3 treatment (9.5 ± 3.53 vs. 10.3 ± 3.83, P = 0.83). Serum parathyroid hormone declined from 3.8 ± 1.5 to 3.1 ± 1 pmol L(-1) (P = 0.01). The remainder of biochemical measurements did not show a significant change.

CONCLUSIONS

Treatment with vitamin D3 , 100 000 IU once a month for 3 months was effective in increasing 25(OH)D levels in obese adolescents but did not impact endothelial function.

Venous thromboembolism and underutilisation of anticoagulant thromboprophylaxis in hospitalised patients with inflammatory bowel disease

BACKGROUND

Venous thromboembolism (VTE) is a well-recognised extra-intestinal manifestation of inflammatory bowel disease (IBD). Despite the widespread support for anticoagulant prophylaxis in hospitalised IBD patients, the utilisation and efficacy in clinical practice are unknown.

AIMS

The aim of this study was to assess the prevalence and clinical features of VTE among hospitalised IBD patients and ascertain whether appropriate thromboprophylaxis had been administered.

METHODS

All patients with a discharge diagnosis of Crohn disease or ulcerative colitis and VTE were retrospectively identified using International Classification of Diseases, tenth revision codes from medical records at our institution from July 1998 to December 2009. Medical records were then reviewed for clinical history and utilisation of thromboprophylaxis. Statistical analysis was performed by Mann-Whitney test and either χ(2) tests or Fisher's exact tests.

RESULTS

Twenty-nine of 3758 (0.8%) IBD admissions suffered VTE, 13 preadmission and 16 during admission. Of these 29 admissions (in 25 patients), 24% required intensive care unit and 10% died. Of the 16 venous thrombotic events that occurred during an admission, eight (50%) did not receive anticoagulant thromboprophylaxis and eight (50%) occurred despite thromboprophylaxis. Most thromboembolism despite prophylaxis occurred post-intestinal resection (n = 5, 63%).

CONCLUSION

Thromboprophylaxis is underutilised in half of IBD patients suffering VTE. Prescription of thromboprophylaxis for all hospitalised IBD patients, including dual pharmacological and mechanical prophylaxis in postoperative patients, may lead to a reduction in this preventable complication of IBD.

Diagnostic performance of body mass index to identify obesity as defined by body adiposity in children and adolescents: a systematic review and meta-analysis

BACKGROUND

The ideal means of identifying obesity in children and adolescents has not been determined although body mass index (BMI) is the most widely used screening tool.

OBJECTIVE

We performed a systematic review and meta-analysis of studies assessing the diagnostic performance of BMI to detect adiposity in children up to 18 years.

METHODS

Data sources were EMBASE, MEDLINE, Cochrane, Database of Systematic Reviews Cochrane CENTRAL, Web of Science and SCOPUS up to March 2013. Studies providing measures of diagnostic performance of BMI and using body composition technique for body fat percentage measurement were included.

RESULTS

Thirty-seven eligible studies that evaluated 53 521 patients, with mean age ranging from 4 to 18 years were included in the meta-analysis. Commonly used BMI cut-offs for obesity showed pooled sensitivity to detect high adiposity of 0.73 (confidence interval [CI] 0.67-0.79), specificity of 0.93 (CI 0.88-0.96) and diagnostic odds ratio of 36.93 (CI 20.75-65.71). Males had lower sensitivity. Moderate heterogeneity was observed (I(2) = 48%) explained in meta-regression by differences across studies in race, BMI cut-off, BMI reference criteria (Center for Disease Control vs. International Obesity Task Force) and reference standard method assessing adiposity.

CONCLUSION

BMI has high specificity but low sensitivity to detect excess adiposity and fails to identify over a quarter of children with excess body fat percentage.

Cosmetic side effects of antiepileptic drugs in adults with epilepsy

OBJECTIVE

Cosmetic side effects (CSEs) such as weight gain and alopecia are common, undesirable effects associated with several AEDs. The objective of the study was to compare the CSE profiles in a large specialty practice-based sample of patients taking both older and newer AEDs.

METHODS

As part of the Columbia and Yale AED Database Project, we reviewed patient records including demographics, medical history, AED use, and side effects for 1903 adult patients (≥16years of age) newly started on an AED. Cosmetic side effects were determined by patient or physician report in the medical record and included acne, gingival hyperplasia, hair loss, hirsutism, and weight gain. We compared the overall rate of CSEs and intolerable CSEs (ICSEs-CSEs that led to dosage reduction or discontinuation) between different AEDs in both monotherapy and polytherapy.

RESULTS

Overall, CSEs occurred in 110/1903 (5.8%) patients and led to intolerability in 70/1903 (3.7%) patients. Weight gain was the most commonly reported CSE (68/1903, 3.6%) and led to intolerability in 63 (3.3%) patients. Alopecia was the second most common patient-reported CSE (36/1903, 1.9%) and was intolerable in 33/1903 (1.7%) patients. Risk factors for CSEs included female sex (7.0% vs. 4.3% in males; p<0.05) and any prior CSE (37% vs. 2.9% in patients without prior CSE; p<0.001). Significantly more CSEs were attributed to valproic acid (59/270; 21.9%; p<0.001) and pregabalin (14/143; 9.8%; p<0.001) than to all other AEDs. Significantly less CSEs were attributed to levetiracetam (7/524; 1.3%; p=0.002). Weight gain was most frequently associated with valproic acid (35/270; 13.0%; p<0.001) and pregabalin (12/143; 8.4%; p<0.001). Hair loss was most commonly reported among patients taking valproic acid (24/270; 8.9%; p<0.001). Finally, gingival hyperplasia was most commonly reported in patients taking phenytoin (10/404; 2.5%; p<0.001). Cosmetic side effects leading to dosage change or discontinuation occurred most frequently with pregabalin and valproic acid compared with all other AEDs (13.3 and 5.6% vs. 2.3%; p<0.001). For patients who had been on an AED in monotherapy (n=677), CSEs and ICSEs were still more likely to be attributed to valproic acid (30.2% and 17.1%, respectively) than to any other AED (both p<0.001).

SIGNIFICANCE

Weight gain and alopecia were the most common patient-reported CSEs in this study, and weight gain was the most likely cosmetic side effect to result in dosage adjustment or medication discontinuation. Particular attention should be paid to pregabalin, phenytoin, and valproic acid when considering cosmetic side effects. Female patients and patients who have had prior CSE(s) to AED(s) were more likely to report CSEs. Knowledge of specific CSE rates for each AED found in this study may be useful in clinical practice.

Acute kidney injury in major gynaecological surgery: an observational study

OBJECTIVE

To assess the prevalence, outcomes and cost associated with acute kidney injury (AKI) defined by consensus risk, injury, failure, loss, and end-stage kidney (RIFLE) criteria after gynaecologic surgery.

DESIGN

Retrospective single-centre cohort study.

SETTING

Academic medical centre.

SAMPLE

Two thousand three hundred and forty-one adult women undergoing major inpatient gynaecologic surgery between January 2000 and November 2010.

METHODS

AKI was defined by RIFLE criteria as an increase in serum creatinine greater than or equal to 50% from the reference creatinine. We used multivariable regression analyses to determine the association between perioperative factors, AKI, mortality and cost.

MAIN OUTCOME MEASURES

AKI, combined major adverse events (hospital mortality, sepsis or mechanical ventilation), 90-day mortality and hospital cost.

RESULTS

Overall prevalence of AKI was 13%. The prevalence of AKI was associated with the primary diagnosis. Of women with benign tumour surgeries, 5% (43/801) experienced AKI compared with 18% (211/1159) of women with malignant disease (P < 0.001). Only 1.3% of the whole cohort had evidence of urologic mechanical injury. In a multivariable logistic regression analysis, AKI patients had nine times the odds of a major adverse event compared to patients without AKI (adjusted odds ratio 8.95, 95% confidence interval 5.27-15.22). We have identified several readily available perioperative factors that can be used to identify patients at high risk for AKI after in-hospital gynaecologic surgery.

CONCLUSIONS

AKI is a common complication after major inpatient gynaecologic surgery associated with an increase in resource utilisation and hospital cost, morbidity and mortality.

Arthroscopic femoral osteochondroplasty for cam femoroacetabular impingement in patients over 60 years of age

We reviewed the clinical outcome of arthroscopic femoral osteochondroplasty for cam femoroacetabular impingement performed between August 2005 and March 2009 in a series of 40 patients over 60 years of age. The group comprised 26 men and 14 women with a mean age of 65 years (60 to 82). The mean follow-up was 30 months (12 to 54).

The mean modified Harris hip score improved by 19.2 points (95% confidence interval 13.6 to 24.9; p < 0.001) while the mean non-arthritic hip score improved by 15.0 points (95% confidence interval 10.9 to 19.1, p < 0.001). Seven patients underwent total hip replacement after a mean interval of 12 months (6 to 24 months) at a mean age of 63 years (60 to 70). The overall level of satisfaction was high with most patients indicating that they would undergo similar surgery in the future to the contralateral hip, if indicated. No serious complications occurred.

Arthroscopic femoral osteochondroplasty performed in selected patients over 60 years of age, who have hip pain and mechanical symptoms resulting from cam femoroacetabular impingement, is beneficial with a minimal risk of complications at a mean follow-up of 30 months.

Elevated expression of Ki-67 identifies aggressive prostate cancers but does not distinguish BRCA1 or BRCA2 mutation carriers

Prostate cancers in men with germline BRCA1 and BRCA2 mutations are more aggressive than morphologically similar cancers in men without these mutations. This study was performed to test the hypothesis that enhanced expression of Ki-67, as a surrogate of cell proliferation, is a characteristic feature of prostate cancers occurring in BRCA1 or BRCA2 mutation carriers. The study cohort comprised 20 cases of prostate cancer in mutation carriers and 126 control sporadic prostate cancers. Of the combined sample cohort, 65.7% stained only within malignant tissues while 0.7% stained in both malignant and benign tissues (p<0.001). Significantly increased expression of Ki-67 occurred in prostate cancers with higher Gleason score (p<0.001). Elevated Ki-67 expression was identified in 71% of prostate cancers in BRCA1 or BRCA2 mutation carriers and in 67% of the sporadic controls (p>0.5). Similar results were obtained when the data were analysed using a threshold set at 3.5 and 7.1%. This study shows that elevated expression of Ki-67 is associated both with aggressive prostate cancers and with high Gleason score irrespective of whether their occurrence is against a background of BRCA1 or BRCA2 mutations or as sporadic disease. The data suggest that, since elevated Ki-67 does not distinguish prostate cancers occurring in BRCA1 or BRCA2 mutation carriers from sporadic prostatic malignancies, the effects of these genetic mutations are probably independent. While all prostate cancers occurring in the presence of BRCA germline mutations are clinically aggressive, their potentially different phenotypes consistently involve maximal rates of cell proliferation.

Minor salivary gland inflammation in Devic’s disease and longitudinally extensive myelitis

Devic’s disease is often considered as a variant of multiple sclerosis (MS). However, evidence suggests that Devic’s disease may be distinct from MS. Devic’s disease can coexist with connective tissue diseases, particularly Sjögren’s disease, but this association is rare with MS. Diagnosis of Sjögren’s disease in patients with neurological symptoms is often difficult. During early stages of Sjögren’s disease, patients may not fulfill all criteria for Sjögren’s disease. A high percentage of patients with Sjögren’s disease have inflammatory infiltrates in minor salivary glands, and this may be a reliable indicator of early or subclinical disease. We show high prevalence (80%) of salivary gland inflammation in Devic’s disease and longitudinally extensive transverse myelitis (LETM). We diagnosed 16 patients with Devic’s disease, and 2 of these satisfied criteria for Sjögren’s disease as did 2 of 9 patients with LETM. Anti-SSA/B titers were infrequently elevated. Although most did not satisfy criteria for Sjögren’s disease. 9 of 12 Devic’s disease patients and 7 of 8 LETM patients had severe salivary gland inflammation. Thus: (1) patients with Devic’s disease or with LETM who have positive labial biopsies but do not satisfy criteria for Sjögren’s disease could have subclinical Sjögren’s diseases. Alternatively, (2) as patients with Devic’s disease have elevated titers of several autoantibodies, so there may exist a set of antibodies that react with antigens in minor salivary glands and cause inflammation. Minor salivary gland biopsy is more sensitive than anti-SSA/B serology in providing histological evidence for possible Sjögren’s disease with CNS lesions.

Functional breast imaging with Tc 99m Mibi for detection of primary breast lesion and axillary lymph node metastases

Breast cancer is the most common cancer among women and the second leading cause of death in women after lung cancer. The principle aim is to study the utility of Tc- MIBI scintimammography in evaluation of breast cancer and lymph node metastases.

MATERIALS AND METHODS

A total of 36 patients both with breast lumps or/and axillary masses suspected breast cancer on clinical examination and/or at conventional imaging procedures (CIP's) were included in this study. The mean age was 47.13 years, median age 47 and age range 22-77 years. All patients received a 740-1000 MBq bolus IV injection of 99mTc-MIBI preferably in a pedal vein. At 5-10 min post injection planar images were obtained in prone lateral and supine anterior position using dual head gamma camera. MIBI uptake was scored as follows: 1 for normal uptake (compared with contralateral side), 2 for focal low intense uptake (equivocal), 3 for focal high intense uptake (positive). All patients had histopathology for tissue diagnosis.

RESULTS

There were 36 patients who presented with breast lesions (30 palpable, 6 non-palpable) and 8 patients with axillary lump. Scan was found true positive in 24 patients and was true negative in 7 patients with breast lesion. In case of axillary lump, it was true positive in 4 and true negative in 2 patients. Planar scintimammography showed sensitivity of 86%, specificity 88%, PPV 96%, NPV 64% and accuracy of 86% (p<0.01). However sensitivity, specificity, PPV, NPV and accuracy for axially metastasis were 86%, 67%, 80%, 67% and 75% respectively. (P-value <0.01).

CONCLUSION

It is concluded from the study that SMM has good diagnostic accuracy in the detection of breast cancer specially in palpable lesion and lymph node metastases.

Regulatory roles of Runx2 in metastatic tumor and cancer cell interactions with bone

The three mammalian Runt homology domain transcription factors (Runx1, Runx2, Runx3) support biological control by functioning as master regulatory genes for the differentiation of distinct tissues. Runx proteins also function as cell context-dependent tumor suppressors or oncogenes. Abnormalities in Runx mediated gene expression are linked to cell transformation and tumor progression. Runx2 is expressed in mesenchymal linage cells committed to the osteoblast phenotype and is essential for bone formation. This skeletal transcription factor is aberrantly expressed at high levels in breast and prostate tumors and cells that aggressively metastasize to the bone environment. In cancer cells, Runx2 activates expression of bone matrix and adhesion proteins, matrix metalloproteinases and angiogenic factors that have long been associated with metastasis. In addition, Runx2 mediates the responses of cells to signaling pathways hyperactive in tumors, including BMP/TGFbeta and other growth factor signals. Runx2 forms co-regulatory complexes with Smads and other co-activator and co-repressor proteins that are organized in subnuclear domains to regulate gene transcription. These activities of Runx2 contribute to tumor growth in bone and the accompanying osteolytic disease, established by interfering with Runx2 functions in metastatic breast cancer cells. Inhibition of Runx2 in MDA-MB-231 cells transplanted to bone decreased tumorigenesis and prevented osteolysis. This review evaluates evidence that Runx2 regulates early metastatic events in breast and prostate cancers, tumor growth, and osteolytic bone disease. Consideration is given to the potential for inhibition of this transcription factor as a therapeutic strategy upstream of the regulatory events contributing to the complexity of metastasis to bone.

Electrochemical investigation of the effect of some organic phosphates on haemoglobin

The effects of DPG,IHP,GTP,GDP and GMP on the structure and stability of haemoglobin were electrochemically investigated with an iodide-modified silver electrode in 0.01 M KNO 3 at pH 7.0.Anodic and cathodic peaks of haemoglobin were observed at 250 mV and 12 mV with a formal potential value of 133 mV vs.Ag/AgCl.The effects of different concentrations of DPG,IHP,GTP,GDP and GMP on the anaerobic redox reaction were determined. The results showed that DPG and IHP can lead to a positive shift in the reduction peak of haemoglobin,indicating that the oxidation peak shift of haemoglobin was small as a result of stabilization of the reduced state and destabilization of the R-like state of haemoglobin.GTP elicited a more positive shift in the cathodic and anodic peaks of haemoglobin at a higher concentration,signifying that it has a low-affinity binding site on haemoglobin.The positive shift of the cathodic and anodic peaks revealed a slight variation in the structure and indicated the unfolding of haemoglobin in the presence of high concentrations of GTP.Our study also showed that GDP and GMP did not cause significant shift the cathodic and anodic peaks of haemoglobin even at high concentrations,refuting the existence of specific GDP-and GMP-binding sites on the protein.Moreover,the iodide-modified silver electrode method proved to be easy and useful in investigating the effects of ligands or other effectors on haemoglobin in solution.

Medical interns knowledge of TB in Pakistan

Of 460 interns from five Pakistani teaching hospitals surveyed, only 22% correctly identified the estimated number of new TB cases in Pakistan. The majority (96%) knew that droplet infection was the usual mode of transmission. Only 38% considered sputum smears for acid-fast bacilli as the best test for diagnosis of pulmonary TB and 43.5% for follow-up during TB treatment. The recommended four-drug anti-TB regimen was prescribed by 56.5% in the initiation phase and the recommended two-drug combination in the continuation phase by 52%. Most interns (82%) were unable to identify a single component of directly observed treatment short course (DOTS) strategy. Our study reflects poor awareness of and low compliance to the World Health Organization/National Tuberculosis Programme guidelines among interns. For effective control of TB, immediate action to improve undergraduate and continuing medical education is essential, with special emphasis on national guidelines.

Nuclear microenvironments: an architectural platform for the convergence and integration of transcriptional regulatory signals

Functional interrelationships between the intranuclear organization of nucleic acids and regulatory proteins are obligatory for fidelity of transcriptional activation and repression. In this article, using the Runx/AML/Cbfa transcription factors as a paradigm for linkage between nuclear structure and gene expression we present an overview of growing insight into the dynamic organization and assembly of regulatory machinery for gene expression at microenvironments within the nucleus. We address contributions of nuclear microenvironments to the convergence and integration of regulatory signals that mediate transcription by supporting the combinatorial assembly of regulatory complexes.

Interobserver variations in intra-articular evaluation during arthroscopy of the knee

We carried out a prospective study in order to establish to what extent the intra-articular evaluation undertaken during arthroscopy of the knee differed between surgeons. Two senior specialist registrars and a consultant orthopaedic surgeon with a special interest in knee surgery were involved. A total of 78 knee arthroscopies (78 patients) was studied. Arthroscopy was first carried out by the trainee and then by the senior author (ACWH). The intra-articular evaluation during the arthroscopy was recorded independently by a third person in the operating theatre. Data were collected to record variations in examination under anaesthesia, the morphology and pathology of the menisci and anterior cruciate ligament and the state of the articular surfaces. The overall interobserver variation was 20% in all categories. We question the published results of intra-articular evaluation during knee arthroscopy when surgeons of different levels of experience are involved in a single study.

Interobserver variations in intra-articular evaluation during arthroscopy of the knee

We carried out a prospective study in order to establish to what extent the intra-articular evaluation undertaken during arthroscopy of the knee differed between surgeons. Two senior specialist registrars and a consultant orthopaedic surgeon with a special interest in knee surgery were involved. A total of 78 knee arthroscopies (78 patients) was studied. Arthroscopy was first carried out by the trainee and then by the senior author (ACWH). The intra-articular evaluation during the arthroscopy was recorded independently by a third person in the operating theatre. Data were collected to record variations in examination under anaesthesia, the morphology and pathology of the menisci and anterior cruciate ligament and the state of the articular surfaces.

The overall interobserver variation was 20% in all categories. We question the published results of intra-articular evaluation during knee arthroscopy when surgeons of different levels of experience are involved in a single study.

Knowledge, attitudes and practices of general practitioners in Karachi District Central about tetanus immunization in adults

OBJECTIVE

To assess the knowledge, attitude and practices of general practitioners regarding tetanus immunization in adults.

SETTING

The study was conducted in District Central, Karachi.

STUDY DESIGN

This was a Knowledge, Attitude and practices (KAP) survey.

METHODS

From a list of 1050 general practitioners (GPs), 100 were selected through simple random sampling and interviewed through a written questionnaire.

RESULTS

Only 25% general practitioners had adequate knowledge about pre-exposure and 13% both pre- and post-exposure tetanus immunization. All were ready to participate in any program to update their knowledge. Ninety seven percent were practicing only post-exposure immunization. In unimmunized patients with history of road side/street injury, 55% started tetanus immunization with tetanus toxoid (TT) only, 43% with Anti Tetanus Serum/Tetanus Immunoglobin (ATS/TIG) and only 2% with both TT and ATS/TIG. Only 13% GPs advised their patients to complete three doses of tetanus toxoid after initial contact.

CONCLUSION

As majority of GPs had poor knowledge and incorrect practices so interventions like seminars and display of immunization protocols in the clinics are recommended.

Differential regulation of the two principal Runx2/Cbfa1 n-terminal isoforms in response to bone morphogenetic protein-2 during development of the osteoblast phenotype

Cbfa1/Runx2 is a transcription factor essential for bone formation and osteoblast differentiation. Two major N-terminal isoforms of Cbfa1, designated type I/p56 (PEBP2aA1, starting with the sequence MRIPV) and type II/p57 (til-1, starting with the sequence MASNS), each regulated by distinct promoters, are known. Here, we show that the type I transcript is constitutively expressed in nonosseous mesenchymal tissues and in osteoblast progenitor cells. Cbfa1 type I isoform expression does not change with the differentiation status of the cells. In contrast, the type II transcript is increased during differentiation of primary osteoblasts and is induced in osteoprogenitors and in premyoblast C2C12 cells in response to bone morphogenetic protein-2. The functional equivalence of the two isoforms in activation and repression of bone-specific genes indicates overlapping functional roles. The presence of the ubiquitous type I isoform in nonosseous cells and before bone morphogenetic protein-2 induced expression of the type II isoform suggests a regulatory role for Cbfa1 type I in early stages of mesenchymal cell development, whereas type II is necessary for osteogenesis and maintenance of the osteoblast phenotype. Our data indicate that Cbfa1 function is regulated by transcription, cellular protein levels, and DNA binding activity during osteoblast differentiation. Taken together, our studies suggest that developmental timing and cell type- specific expression of type I and type II Cbfa isoforms, and not necessarily molecular properties or sequences that reside in the N-terminus of Cbfa1, are the principal determinants of the osteogenic activity of Cbfa1.

A specific targeting signal directs Runx2/Cbfa1 to subnuclear domains and contributes to transactivation of the osteocalcin gene

Key components of DNA replication and the basal transcriptional machinery as well as several tissue-specific transcription factors are compartmentalized in specialized nuclear domains. In the present study, we show that determinants of subnuclear targeting of the bone-related Runx2/Cbfa1 protein reside in the C-terminus. With a panel of C-terminal mutations, we further demonstrate that targeting of Runx2 to discrete subnuclear foci is mediated by a 38 amino acid sequence (aa 397-434). This nuclear matrix-targeting signal (NMTS) directs the heterologous Gal4 protein to nuclear-matrix-associated Runx2 foci and enhances transactivation of a luciferase gene controlled by Gal4 binding sites. Importantly, we show that targeting of Runx2 to the NM-associated foci contributes to transactivation of the osteoblast-specific osteocalcin gene in osseous cells. Taken together, these findings identify a critical component of the mechanisms mediating Runx2 targeting to subnuclear foci and provide functional linkage between subnuclear organization of Runx2 and bone-specific transcriptional control.

Subnuclear organization and trafficking of regulatory proteins: implications for biological control and cancer

The regulated and regulatory components that interrelate nuclear structure and function must be experimentally established. A formidable challenge is to define further the control of transcription factor targeting to acceptor sites associated with the nuclear matrix. It will be important to determine whether acceptor proteins are associated with a pre-existing core-filament structural lattice or whether a compositely organized scaffold of regulatory factors is dynamically assembled. An inclusive model for all steps in the targeting of proteins to subnuclear sites cannot yet be proposed. However, this model must account for the apparent diversity of intranuclear targeting signals. It is also important to assess the extent to which regulatory discrimination is mediated by subnuclear domain-specific trafficking signals. Furthermore, the checkpoints that monitor subnuclear distribution of regulatory factors and the sorting steps that ensure both structural and functional fidelity of nuclear domains in which replication and expression of genes occur must be biochemically and mechanistically defined. There is emerging recognition that placement of regulatory components of gene expression must be temporally and spatially coordinated to facilitate biological control. The consequences of breaches in nuclear structure-function relationships are observed in an expanding series of diseases that include cancer [Weis et al., 1994; Rogaia et al., 1997; Yano et al., 1997; Rowley, 1998; Zeng et al., 1998; McNeil et al., 1999; Tao and Levine, 1999a] and neurological disorders [Skinner et al., 1997]. As the repertoire of architecture-associated regulatory factors and cofactors expands, workers in the field are becoming increasingly confident that nuclear organization contributes significantly to control of transcription. To gain increased appreciation for the complexities of subnuclear organization and gene regulation, we must continue to characterize mechanisms that direct regulatory proteins to specific transcription sites within the nucleus so that these proteins are in the right place at the right time. J. Cell. Biochem. Suppl. 35:84-92, 2000.

Subnuclear targeting of Runx/Cbfa/AML factors is essential for tissue-specific differentiation during embryonic development

Runx (Cbfa/AML) transcription factors are critical for tissue-specific gene expression. A unique targeting signal in the C terminus directs Runx factors to discrete foci within the nucleus. Using Runx2/CBFA1/AML3 and its essential role in osteogenesis as a model, we investigated the fundamental importance of fidelity of subnuclear localization for tissue differentiating activity by deleting the intranuclear targeting signal via homologous recombination. Mice homozygous for the deletion (Runx2 Delta C) do not form bone due to maturational arrest of osteoblasts. Heterozygotes do not develop clavicles, but are otherwise normal. These phenotypes are indistinguishable from those of the homozygous and heterozygous null mutants, indicating that the intranuclear targeting signal is a critical determinant for function. The expressed truncated Runx2 Delta C protein enters the nucleus and retains normal DNA binding activity, but shows complete loss of intranuclear targeting. These results demonstrate that the multifunctional N-terminal region of the Runx2 protein is not sufficient for biological activity. We conclude that subnuclear localization of Runx factors in specific foci together with associated regulatory functions is essential for control of Runx-dependent genes involved in tissue differentiation during embryonic development.

5-HT2A receptors stimulate ACTH, corticosterone, oxytocin, renin, and prolactin release and activate hypothalamic CRF and oxytocin-expressing cells

The 5-HT(2A/2C) agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOI) stimulates hypothalamic neurons to increase the secretion of several hormones. This study addressed two questions: 1) are the neuroendocrine effects of DOI mediated via activation of 5-HT(2A) receptors; and 2) which neurons are activated by 5-HT(2A) receptors. The 5-HT(2A) antagonist (+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidinemethanol (MDL 100,907; 0.001, 0.01, or 0.1 mg/kg, s.c.) was administered before rats were challenged with DOI (2.5 mg/kg, i.p.). MDL 100,907 produced a dose-dependent inhibition (ED(50) congruent with 0.001 mg/kg) of the effect of DOI on plasma levels of ACTH, corticosterone, oxytocin, prolactin, and renin without altering basal hormone levels. Complete blockade of the effect of DOI was achieved for all hormones at MDL 100,907 doses of 0.01-0.1 mg/kg. In a parallel experiment, DOI was injected 2 hr before killing to determine its effects on the expression of Fos, the product of the immediate early gene c-fos. DOI induced an increase in Fos immunoreactivity in corticotropin-releasing factor (CRF) and in oxytocin-expressing neurons but not in vasopressin-containing neurons in the hypothalamic paraventricular nucleus or CRF cells in the amygdala. Pretreatment with MDL 100,907 (0.1 mg/kg, s.c.) blocked the DOI-induced increase in Fos expression in all regions including the hypothalamus, amygdala (central and corticomedial), bed nucleus of the stria terminalis, and prefrontal cortical regions. The combined neuroanatomical and pharmacological observations suggest that the neuroendocrine responses to DOI are mediated by activation of neurons in the hypothalamic paraventricular nucleus and associated circuitry. Furthermore, selective activation of 5-HT(2A) receptors mediates the hormonal and Fos-inducing effects of DOI.

Expression and regulation of Runx2/Cbfa1 and osteoblast phenotypic markers during the growth and differentiation of human osteoblasts

The runt family transcription factor (AML-3/PEBP2alphaA1/Cbfa1/RUNX2) plays a crucial role in formation of the mineralized skeleton during embryogenesis and regulates maturation of the osteoblast phenotype. Because steroid hormones and growth factors significantly influence growth and differentiation properties of osteoblasts, we addressed Cbfa1 as a target gene for regulation by dexamethasone (Dex), 1,25(OH)D(3) (vitamin D(3)), 17beta-estradiol, and transforming growth factor-beta1 (TGF-beta1). The representation of functional protein levels by Western blot analyses and gel mobility shift assays was examined during the growth and mineralization of several conditionally immortalized human osteoblast cell lines HOB 04-T8, 03-CE6, and 03-CE10, each representing different stages of maturation. In situ immunofluorescence demonstrates Cbfa1 is associated with nuclear matrix in punctate domains, some of which are transcriptionally active, colocalizing with phosphorylated RNA polymerase II. Although each of the cell lines exhibited different responses to the steroid hormones and to TGF-beta1, all cell lines showed a similar increase in Cbfa1 protein and DNA binding activity induced only by Dex. On the other hand, Cbfa1 mRNA levels were not altered by Dex treatment. This regulation of Cbfa1 by steroid hormones in human osteoblasts contrasts to modifications in Cbfa1 expression in primary rat calvarial osteoblasts and the mouse MC3T3-E1 osteoblast cell line. Thus, these results reveal multiple levels of regulation of Cbfa1 expression and activity in osteoblasts. Moreover, the data suggest that in committed human osteoblasts, constitutive expression of Cbfa1 may be required to sustain the osteoblast phenotype.

Arthrography for reduction of a fracture of the radial neck in a child with a non-ossified radial epiphysis

A fracture of the neck of the radius when the head is not ossified can be difficult to assess and treat. In a four-year-old child we suspected from the radiographs that there was an O'Brien type-III injury after trauma. Partial manual reduction of the non-ossified radial head was completed using the Métaizeau technique of intramedullary Kirschner (K-) wiring aided by intraoperative arthrography. The child had a full range of movement at the elbow and wrist when reviewed 11 weeks after the injury, three weeks after removal of the K-wire. We suggest that intraoperative arthrography is a useful complement to the Métaizeau technique for successful reduction of fractures of the radial neck in the presence of a non-ossified radial head.

ARTHROGRAPHY FOR REDUCTION OF A FRACTURE OF THE RADIAL NECK IN A CHILD WITH A NON-OSSIFIED RADIAL EPIPHYSIS

A fracture of the neck of the radius when the head is not ossified can be difficult to assess and treat. In a four-year-old child we suspected from the radiographs that there was an O’Brien type-III injury after trauma. Partial manual reduction of the non-ossified radial head was completed using the Métaizeau technique of intramedullary Kirschner (K-) wiring aided by intraoperative arthrography. The child had a full range of movement at the elbow and wrist when reviewed 11 weeks after the injury, three weeks after removal of the K-wire. We suggest that intraoperative arthrography is a useful complement to the Métaizeau technique for successful reduction of fractures of the radial neck in the presence of a non-ossified radial head.

runt homology domain transcription factors (Runx, Cbfa, and AML) mediate repression of the bone sialoprotein promoter: evidence for promoter context-dependent activity of Cbfa proteins

Expression of the bone sialoprotein (BSP) gene, a marker of bone formation, is largely restricted to cells in mineralized tissues. Recent studies have shown that the Cbfa1 (also known as Runx2, AML-3, and PEBP2alphaA) transcription factor supports commitment and differentiation of progenitor cells to hypertrophic chondrocytes and osteoblasts. This study addresses the functional involvement of Cbfa sites in expression of the Gallus BSP gene. Gel mobility shift analyses with nuclear extracts from ROS 17/2.8 osteoblastic cells revealed that multiple Cbfa consensus sequences are functional Cbfa DNA binding sites. Responsiveness of the 1.2-kb Gallus BSP promoter to Cbfa factors Cbfa1, Cbfa2, and Cbfa3 was assayed in osseous and nonosseous cells. Each of the Cbfa factors mediated repression of the wild-type BSP promoter, in contrast to their well known activation of various hematopoietic and skeletal phenotypic genes. Suppression of BSP by Cbfa factors was not observed in BSP promoters in which Cbfa sites were deleted or mutated. Expression of the endogenous BSP gene in Gallus osteoblasts was similarly downregulated by forced expression of Cbfa factors. Our data indicate that Cbfa repression of the BSP promoter does not involve the transducin-like enhancer (TLE) proteins. Neither coexpression of TLE1 or TLE2 nor the absence of the TLE interaction motif of Cbfa1 (amino acids 501 to 513) influenced repressor activity. However, removal of the C terminus of Cbfa1 (amino acids 362 to 513) relieved suppression of the BSP promoter. Our results, together with the evolutionary conservation of the seven Cbfa sites in the Gallus and human BSP promoters, suggest that suppressor activity by Cbfa is of significant physiologic consequence and may contribute to spatiotemporal expression of BSP during bone development.

Contributions of nuclear architecture and chromatin to vitamin D-dependent transcriptional control of the rat osteocalcin gene

The vitamin D response element in the bone tissue-specific osteocalcin gene has served as a prototype for understanding molecular mechanisms regulating physiologic responsiveness of vitamin D-dependent genes in bone cells. We briefly review factors which contribute to vitamin D transcriptional control. The organization of the vitamin D response element (VDRE), the multiple activities of the vitamin D receptor transactivation complex, and the necessity for protein-protein interactions between the VDR-RXR heterodimer activation complex and DNA binding proteins at other regulatory elements, including AP-1 sites and TATA boxes, provide for precise regulation of gene activity in concert with basal levels of transcription. We present evidence for molecular mechanisms regulating vitamin D-dependent mediated transcription of the osteocalcin gene that involve chromatin structure of the gene and nuclear architecture. Modifications in nucleosomal organization, DNase I hypersensitivity and localization of vitamin D receptor interacting proteins in subnuclear domains are regulatory components of vitamin D-dependent gene transcription. A model is proposed to account for the inability of vitamin D induction of the osteocalcin gene in the absence of ongoing basal transcription by competition of the YY1 nuclear matrix-associated transcription factor for TFIIB-VDR interactions. Activation of the VDR-RXR complex at the OC VDRE occurs through modifications in chromatin mediated in part by interaction of OC gene regulatory sequences with the nuclear matrix-associated Cbfa1 (Runx2) transcription factor which is required for osteogenesis.

Leukemia-associated AML1/ETO (8;21) chromosomal translocation protein increases the cellular representation of PML bodies

Promyelocytic leukemia (PML) nuclear bodies are important components of nuclear architecture that are functionally linked to aberrant gene expression and disease. To understand the mechanisms that modify subnuclear distribution and regulatory activities of PML domains in leukemia, we performed immunofluorescence microscopy with a panel of normal diploid cells and established cell lines. We analyzed the representation and intranuclear distribution of PML domains. We find that multiple biological parameters contribute to heterogeneity in the subnuclear organization of PML domains in a broad spectrum of cell types. The subnuclear organization of PML domains was also evaluated following transient transfection with a series of vectors expressing normal hematopoietic and leukemia-related transcription factors. Our results show that expression of a chimeric transcription factor encoded by the tumor related chromosomal translocation (8;21) involving the AML1 and ETO loci is sufficient to cause reorganization of PML domains. This finding increases our understanding of the mechanisms by which the AML1/ETO protein may contribute to modified gene expression linked to the onset and progression of t(8;21) related acute myelogenous leukemia.

Intranuclear trafficking of transcription factors: implications for biological control

The subnuclear organization of nucleic acids and cognate regulatory factors suggests that there are functional interrelationships between nuclear structure and gene expression. Nuclear proteins that are localized in discrete domains within the nucleus include the leukemia-associated acute myelogenous leukemia (AML) and promyelocytic leukemia (PML) factors, the SC-35 RNA-processing factors, nucleolar proteins and components of both transcriptional and DNA replication complexes. Mechanisms that control the spatial distribution of transcription factors within the three-dimensional context of the nucleus may involve the sorting of regulatory information, as well as contribute to the assembly and activity of sites that support gene expression. Molecular, cellular, genetic and biochemical approaches have identified distinct protein segments, termed intranuclear-targeting signals, that are responsible for directing regulatory factors to specific subnuclear sites. Gene rearrangements that remove or alter intranuclear-targeting signals are prevalent in leukemias and have been linked to altered localization of regulatory factors within the nucleus. These modifications in the intranuclear targeting of transcription factors might abrogate fidelity of gene expression in tumor cells by influencing the spatial organization and/or assembly of machineries involved in the synthesis and processing of gene transcripts.

Groucho/TLE/R-esp proteins associate with the nuclear matrix and repress RUNX (CBF(alpha)/AML/PEBP2(alpha)) dependent activation of tissue-specific gene transcription

The Runt related transcription factors RUNX (AML/CBF(alpha)/PEBP2(alpha)) are key regulators of hematopoiesis and osteogenesis. Using co-transfection experiments with four natural promoters, including those of the osteocalcin (OC), multi drug resistance (MDR), Rous Sarcoma Virus long terminal repeat (LTR), and bone sialoprotein (BSP) genes, we show that each of these promoters responds differently to the forced expression of RUNX proteins. However, the three RUNX subtypes (i.e. AML1, AML2, and AML3) regulate each promoter in a similar manner. Although the OC promoter is activated in a C terminus dependent manner, the MDR, LTR and BSP promoters are repressed by three distinct mechanisms, either independent of or involving the AML C terminus, or requiring only the conserved C-terminal pentapeptide VWRPY. Using yeast two hybrid assays we find that the C terminus of AML1 interacts with a Groucho/TLE/R-esp repressor protein. Co-expression assays reveal that TLE proteins repress AML dependent activation of OC gene transcription. Western and northern blot analyses suggest that TLE expression is regulated reciprocally with the levels of OC gene expression during osteoblast differentiation. Digital immunofluorescence microscopy results show that TLE1 and TLE2 are both associated with the nuclear matrix, and that a significant subset of each colocalizes with AML transcription factors. This co-localization of TLE and AML proteins is lost upon removing the C terminus of AML family members. Our findings indicate that suppression of AML-dependent gene activation by TLE proteins involves functional interactions with the C terminus of AML at the nuclear matrix in situ. Our data are consistent with the concept that the C termini of AML proteins support activation or repression of cell-type specific genes depending on the regulatory organization of the target promoter and subnuclear localization.

The CCAAT displacement protein/cut homeodomain protein represses osteocalcin gene transcription and forms complexes with the retinoblastoma protein-related protein p107 and cyclin A

Developmental control of bone tissue-specific genes requires positive and negative regulatory factors to accommodate physiological requirements for the expression or suppression of the encoded proteins. Osteocalcin (OC) gene transcription is restricted to the late stages of osteoblast differentiation. OC gene expression is suppressed in nonosseous cells and osteoprogenitor cells and during the early proliferative stages of bone cell differentiation. The rat OC promoter contains a homeodomain recognition motif within a highly conserved multipartite promoter element (OC box I) that contributes to tissue-specific transcription. In this study, we demonstrate that the CCAAT displacement protein (CDP), a transcription factor related to the cut homeodomain protein in Drosophila melanogaster, may regulate bone-specific gene transcription in immature proliferating osteoblasts. Using gel shift competition assays and DNase I footprinting, we show that CDP/cut recognizes two promoter elements (TATA and OC box I) of the bone-related rat OC gene. Overexpression of CDP/cut in ROS 17/2.8 osteosarcoma cells results in repression of OC promoter activity; this repression is abrogated by mutating OC box I. Gel shift immunoassays show that CDP/cut forms a proliferation-specific protein/DNA complex in conjunction with cyclin A and p107, a member of the retinoblastoma protein family of tumor suppressors. Our findings suggest that CDP/cut may represent an important component of a cell signaling mechanism that provides cross-talk between developmental and cell cycle-related transcriptional regulators to suppress bone tissue-specific genes during proliferative stages of osteoblast differentiation.