Clopidogrel inhibits the binding of ADP analogues to the receptor mediating inhibition of platelet adenylate cyclase

Clopidogrel, like the homologous thienopyridine derivative ticlopidine, selectively inhibits platelet aggregation induced by ADP. We have previously described two nucleotide-binding sites on platelets related to ADP-mediated platelet responses. The first is a high-affinity binding site for 2-methylthio-ADP (2-MeSADP) that is linked to the inhibition of stimulated adenylate cyclase. The second is the 100-kd exofacial membrane protein aggregin, which is labeled by the reactive ADP analogue 5'-p-fluorosulfonylbenzoyl adenosine (FSBA) that is related to shape change and aggregation. We set out to determine if either of these sites is blocked in vivo by clopidogrel or its active metabolite. Six subjects were given clopidogrel (75 mg/day for 10 days) in a double-blind crossover experiment. All of the subjects developed prolonged bleeding times while taking the drug. The rate of onset of the effect on bleeding time varied among subjects. Platelet aggregation induced by ADP or thrombin was significantly impaired by the drug treatment, but no effect was detected on shape change. The incorporation of [3H]FSBA into aggregin was also unaffected. Inhibition of adenylate cyclase by ADP or by 2-MeSADP was greatly reduced in all subjects, and in the case of 2-MeSADP, there was evidence for a noncompetitive effect. Inhibition of adenylate cyclase by epinephrine was unaffected. In the three subjects for whom binding measurements were made, the number of binding sites for [32P]2-MeSADP was reduced from 534 +/- 44 molecules per platelet during control and placebo periods (11 determinations) to 199 +/- 78 molecules per platelet during drug treatment (three determinations). There was no consistent change in the binding affinity.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular cloning of pituitary tumor transforming gene 1 from ovarian tumors and its expression in tumors

Pituitary tumor transforming gene 1 (PTTG1) recently cloned from human testis is a potent oncogene and is highly expressed in all the tumors analyzed to date. However, primary structure of PTTG1 and the cell types that express PTTG1 in tumors remained undescribed. We have used the reverse transcriptase-polymerase chain reaction technique to clone PTTG1 from ovarian tumors. Nucleotide sequencing of the PTTG1 cDNAs from various ovarian tumors showed identity with that of the human testis PTTG1. To determine the cell types that express PTTG1 in normal and tumor tissues, we performed in situ hybridization using digoxigenin-labeled cRNA as a probe. Our studies revealed a high level of expression of PTTG1 mRNA in both seminomatous and non-seminomatous testicular tumors; epithelial, sex-cord and stromal cell, and germ cell tumors of the ovary; and invasive ductal, ductal in situ and infiltrating ductal carcinoma of the breast. In normal tissues, expression of PTTG1 mRNA was very low or undetectable except in testis, where PTTG1 mRNA was found to be localized to spermatocytes and spermatids. Tumors that expressed high levels of PTTG1 mRNA also exhibited high levels of expression of basic fibroblast growth factor (bFGF), suggesting a correlation between PTTG1 and bFGF expression, and further suggesting that the PTTG1 protein may be involved in tumor angiogenesis and mitogenesis.

Identification of the human pituitary tumor transforming gene (hPTTG) family: molecular structure, expression, and chromosomal localization

In an attempt to determine the mechanism of human tumorigenesis, we have searched for oncogenes and recently reported the molecular cloning of a potent oncogene (hPTTG) from human testis. hPTTG mRNA is expressed at high levels in various human tumors and tumor cell lines. Overexpression of hPTTG in the mouse fibroblast cell line (NIH 3T3) results in an increase in cell proliferation, induces cellular transformation in vitro, and promotes tumor formation in nude mice. The hPTTG gene isolated from the human genomic library consists of five exons and four introns and spans over 10kb. In the studies reported here, we further investigated the possibility of the presence of additional genes homologous to hPTTG in the human genome, which was first indicated by Southern blot analysis of the human genomic DNA and chromosomal mapping of the hPTTG gene using DNA from humanxhamster hybrid cell lines in PCR. Sequencing and restriction map analysis of the additional genomic clones identified two intronless genes homologous to hPTTG. This finding was confirmed by the chromosomal location of the second gene to chromosome 4p15.1 and the third gene to chromosome 8q13.1. Based on the similarity in sequences, we proposed that hPTTG be renamed hPTTG1 and the new genes be named hPTTG2 and hPTTG3. hPPTG2 was found to be 91% identical and hPPTG3 89% identical with hPPTG1 at the amino acid level. Northern blot and reverse transcriptase/polymerase chain reaction (RT/PCR) analyses of the mRNA from various human tissues revealed differential expression of the hPTTG2 and hPTTG3 genes in normal and tumor tissues, suggesting that these genes may be associated with tumorigenesis.

Valgus deformity of the ankle in children with spina bifida aperta

Valgus deformity of the hindfoot can occur at the subtalar joint, the ankle joint, or at both sites. In children suffering from spina bifida, the ankle is often the main site of deformity. Thirty-five ankles with valgus deformity of the hindfoot were studied in 23 children with spina bifida. A radiological triad was observed in all patients: shortening of the fibula, lateral wedging of the distal tibial epiphysis, and lateral tilt of the talus at the ankle mortise . There was a definite correlation between the severity of wedging and the degree of talar tilt, and a fair correlation between the severity of wedging and the extent of fibular shortening. The results of operation in 12 feet are presented. It is concluded that any operations performed below the ankle on these patients (subtalar fusion or triple arthrodesis) is unlikely to succeed; the deformity needs to be corrected above the ankle (by epiphysiodesis or supramalleolar osteotomy). Radiological assessment of the ankle by taking weight-bearing films in the anteroposterior plane is essential to determine the true extent of the deformity before undertaking any operation.

Endoscopic ultrasound-guided fine-needle aspiration cytology in the evaluation of suspected tuberculosis in patients with isolated mediastinal lymphadenopathy

BACKGROUND AND STUDY AIMS

Patients with suspected tuberculosis without pulmonary lesions and with mediastinal lymphadenopathy often pose a diagnostic challenge. Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) cytology is an established modality to evaluate mediastinal and abdominal lesions. The aim of the present study was to evaluate the role of EUS-FNA in isolated mediastinal lymphadenopathy in patients suspected of having tuberculosis.

METHODS

Consecutive patients suspected of having tuberculosis with isolated mediastinal lymphadenopathy were included in a prospective study. Mediastinal lymphadenopathy was diagnosed on a contrast-enhanced computed tomography scan of the chest. Patients with concomitant lung parenchymal lesions were excluded. Previous attempts to diagnose the etiology of lymphadenopathy had failed in 69 % of patients. EUS-FNA was performed on an outpatient basis under conscious sedation. The sensitivity, specificity, and diagnostic accuracy of EUS-FNA were calculated.

RESULTS

A total of 60 consecutive patients (mean age 39.8 years, 58 % males) with mediastinal lymphadenopathy were included. EUS confirmed the presence of mediastinal lymph nodes ranging in size from 8 mm to 40 mm (mean 26 mm) in all patients. EUS-FNA provided an adequate tissue sample in 54 patients during the first examination and repeat EUS-FNA was necessary in six patients. A final diagnosis was obtained by EUS-FNA in 42 patients (tuberculosis in 32, sarcoidosis in six, and Hodgkin's disease in four patients). An additional 14 patients were treated for tuberculosis based on EUS-FNA and clinical features. Mediastinoscopy was required for diagnosis in the remaining four patients. EUS-FNA had an overall diagnostic yield of 93 %, sensitivity of 71 %, specificity of 100 %, and positive predictive value of 100 %.

CONCLUSION

EUS-FNA is an accurate, safe, and minimally invasive modality for evaluating isolated mediastinal lymphadenopathy in patients suspected of having tuberculosis in an endemic area with a high prevalence of tuberculosis.

Hypothalamic control of nocireceptive and other neurons in the marginal layer of the dorsal horn of the medulla (trigeminal nucleus caudalis) in the rat

The effect of electrical stimulation of the preoptic area of the hypothalamus on the discharge of neurones in the marginal layer (lamina I) of the trigeminal nucleus caudalis was studied in the anaesthetised rat. There was a powerful suppression of the discharge evoked by noxious thermal stimuli in 49/49 specific nociceptor driven (nocireceptive) neurones. The inhibitory effect increased with graded increases in the intensity of preoptic stimulation. Stimulation, however, produced only a small reduction in the discharge of 14/17 cold receptive neurones. Thresholds for producing suppression of cold receptive neurones were generally higher than those for nocireceptive neurones. There was no effect on the activity of 12/12 low threshold mechanoreceptive neurones. The inhibitory action generated on the activity of nocireceptive neurones was reduced by electrolytic lesions in the nucleus raphe magnus (NRM) or the nucleus paragigantocellularis lateralis (PGCL) or the dorsolateral and ventrolateral periaqueductal gray matter (PAG). Lesions made in the ventral or dorsal aspect of PAG were, however, ineffective in reducing the suppression. It is suggested that the powerful descending inhibitory control of nociceptive transmission in the trigeminal nucleus caudalis is one of the neuronal mechanisms mediating analgesia from the preoptic area of the hypothalamus.

Randomised, placebo controlled, double blind study of alfuzosin SR in patients undergoing trial without catheter following acute urinary retention

INTRODUCTION

Acute urinary retention caused by bladder outlet obstruction resulting from prostatic enlargement is one of the commonest causes for acute admission to urology wards. More recently, there has been a trend to commence treatment with alpha-blockers after catheterisation followed by a trial without catheter (TWOC), in the hope that surgery may be avoided in a significant proportion of patients. There is no conclusive evidence of the efficacy of this treatment. We conducted a study to evaluate the efficacy of using the alpha-blocker alfuzosin SR in patients with acute urinary retention.

PATIENTS AND METHODS

All patients presenting with acute urinary retention to our unit were included in the trial. Exclusion criteria included patients with known bladder or prostate malignancy, bladder calculi, urinary tract infections, urethral stricture or patients on alpha-blockers. A total of 81 patients consented and were randomised. Sixty-two patients completed the study. The retention volume was recorded. Trial medicine was recorded on a twice-daily dose and the first TWOC was carried out after a minimum of three doses or 36 hours after admission. TWOC was considered successful on voiding with a residual volume of <200 ml. Unsuccessful patients were recatheterised and discharged home on trial medication, and called for a second TWOC after 2 weeks. Successful patients were continued on alpha-blockers and failures were put on the operating list for TURP. Patients on active treatments were reviewed at 2 year.

RESULTS

Of the 34 patients treated with alfuzosin SR, 17 (50%) resumed voiding and of the 28 patients from placebo group, 16 (57%) voided successfully. All 33 patients were continued open labelled on alfuzosin SR 5mg BD. Out of 33 patients, 13 (43%) had TURP within first year after TWOC and three died due to various medical causes. Out of remaining 17 patients, 15 attended for follow-up. The mean peak flow rate was 8.4 ml/s and the mean residual volume was 112 ml. Six patients (40%) required TURP for severe lower urinary tract symptoms (LUTS). So out of 28 patients followed at 2 year, 19 (68%) had TURP.

CONCLUSIONS

These data do not support the routine use of alpha-blockers in patients with acute urinary retention. Also continuing use of alpha-blockers does not seem to prevent further requirements of TURP, although larger studies are needed to support this.

Esophageal tuberculosis: role of endoscopic ultrasound in diagnosis

Esophageal involvement by tuberculosis is rare and is commonly secondary to mediastinal lymph nodal involvement. Endoscopic ultrasound (EUS) is a good modality for evaluation of both esophageal wall and mediastinal lymph nodes. The objectives were to study the role of EUS in diagnosing esophageal tuberculosis, to differentiate primary from secondary form, and to assess the response. Retrospective analysis of data over 7 years (i.e. from 2003 to 2009) was used. The study was set in a tertiary care referral institute and focused on patients diagnosed with esophageal tuberculosis. Interventions used included endoscopy, EUS, EUS-FNA (fine needle aspiration) followed by antituberculosis treatment. The main outcome measurements were symptoms, endoscopic features, EUS features, pathological yield, and response to treatment. There were 32 cases of esophageal tuberculosis. The primary symptom was dysphagia, and endoscopy showed ulcers in 18/32 (56.25%) and extrinsic bulge in 20/32 (62.5%) in middle one third of esophagus. EUS showed lymph nodes adjacent to esophageal pathology in all cases. Subcarinal region was the most common site of lymphadenopathy and they were matted, heterogeneous with predominantly hypoechoic center. Histopathology of endoscopic biopsy of ulcers and EUS-FNA of lymph nodes provided the diagnosis of tuberculosis in 27/32 (84.35%). All patients were treated with antitubercular treatment and showed good clinical, endoscopic and endosonographic response. This is a retrospective study, and PCR and culture for Mycobacterium tuberculosis were not done. Esophageal tuberculosis does not appear to be a primary disease and is most likely secondary to mediastinal nodal tuberculosis. A conglomerated mass of heterogeneous with predominantly hypoechoic lymph nodes with intervening hyperechoic strands and foci on EUS appears to be characteristic of mediastinal tuberculosis.

Ehretianone, a novel quinonoid xanthene from Ehretia buxifolia with antisnake venom activity

Ehretianone (1), a new quinonoid xanthene, together with known sterols, was isolated from a MeOH extract of the root bark of Ehretia buxifolia. The structure of ehretianone was elucidated as 7-hydroxy-9a alpha-(3-methylbut-2-enyl)-4a alpha,9 alpha-(2-methylprop-2-enyl)-4a, 9a-dihydro-1,4-dioxoxanthene on the basis of spectroscopic data and X-ray crystallographic analysis. The antisnake venom activity of ehretianone against Echis carinatus venom in mice is also reported.

Expression of HIF-1alpha and Glut-1 in human bladder cancer

HIF-1 is a heterodimer consisting of the HIF-1alpha and HIF-1beta subunits, and HIF-1alpha is the unique oxygen regulated subunit that determines HIF-1 activity. HIF-1alpha upgrades many gene products which include the glucose transporter protein 1 (Glut-1). Immunohistochemical studies using a monoclonal antibody specific for HIF-1alpha indicate that the overexpression of HIF-1alpha occurs in the most common forms of human cancer, including bladder cancer. The expression of Glut-1 in human bladder cancer is associated with poor prognosis and a low survival rate. To our knowledge, this is the first study to compare the expression of both HIF-1alpha and Glut-1 with clinicopathological characteristics in superficial and invasive human bladder cancer (all invasive bladder cancer patients received radical radiotherapy). The Kaplan-Meier survival analysis curve shows a significant association of HIF-1alpha expression with recurrence and survival in superficial bladder cancer and shows a significant association of Glut-1 with survival in invasive bladder cancer [chi2 (4)=10.52; Pr >chi2 =0.0012].

Slipped upper femoral epiphysis and primary juvenile hypothyroidism

The pathogenesis of slipped upper femoral epiphysis is unknown but the condition has been linked with various endocrine disorders. Nine patients with slipped epiphyses in association with primary juvenile hypothyroidism are presented. In all patients, slipping occurred or symptoms developed in the affected hip before the hypothyroidism was diagnosed. A generalised pathology was suggested by the absence of trauma (8 patients), by bilateral slipping (6 patients), and by obesity and short stature in all patients. All cases had delayed skeletal maturation and characteristic metaphysial changes were seen on their radiographs. The clinical diagnosis of juvenile hypothyroidism can be difficult but it merits consideration in patients who have a slipped upper femoral epiphysis in association with short stature, obesity, delay in skeletal maturity, or any one of these.

Is using lignocaine gel prior to flexible cystoscopy justified? A randomized prospective study

OBJECTIVE

We evaluate the discomfort and efficacy of instilling 2% lignocaine gel (Instillagel) versus smearing water-soluble gel (Aquagel) around the flexible cystoscope and external urethral meatus in men undergoing flexible cystoscopy for the first time and the overall efficacy of lignocaine gel in completion of the procedure.

MATERIALS AND METHODS

A total of 140 patients divided into two groups, were randomized for this study: group A (n = 70) received approximately 11 ml of 2% lignocaine gel (Instillagel) intraurethrally for approximately 15 min, while in group B (n = 70) approximately 10-15 ml of water-soluble gel (Aquagel) was smeared around the scope and external urethral meatus. Total completion time for each procedure was recorded. Primary outcomes were pain during instillation of lignocaine, during insertion of scope and cystoscopy. Pain was recorded by the patient using a 100-mm nongraphic rating visual analogue scale. Secondary outcome included procedure time and cost analysis.

RESULTS

The majority of patients in both groups reported mild pain with VAS 3 or less throughout the whole procedure. No significant difference was noted in the two groups at any stage of the procedure. Use of lignocaine gel added approximately 10 min to the procedure time.

CONCLUSIONS

In our study there was no significant difference in patient discomfort between instilling lignocaine gel and smearing of Aquagel in completion of flexible cystoscopy. However, application of lignocaine gel added extra time, effort and cost to the procedure.

Very late stent fracture associated with a sirolimus-eluting stent

Late stent thrombosis (>1 year after implantation) is a recognised complication involving drug-eluting stents. Stent fracture is increasingly being reported as a complication of drug-eluting stent, and in particular sirolimus-eluting stent use. We report the case of very late sirolimus-eluting stent fracture resulting in an acute coronary syndrome. This case report highlights the need for greater awareness and post-marketing surveillance to detect a potential mechanism for late stent thrombosis in the drug-eluting stent era.

Nocturnal enuresis in pediatric sickle cell disease

To assess the prevalence of nocturnal enuresis in children and adolescents with sickle cell disease (SCD) and associated factors, structured telephone interviews were conducted with primary caregivers of 217 children and adolescents with SCD aged 5 years or older. Prevalence, perceived causes, interventions undertaken, and emotional impact were assessed. Nocturnal enuresis was significantly higher for males (28.2% of males) than for females (11% of females), p = .002, and compared with cited population prevalence rates, nocturnal enuresis was significantly higher for children with SCD, p < .01. SCD was the most common reason given by primary caregivers for enuresis. Primary caregivers used a wide range of interventions for nocturnal enuresis, but few used empirically supported treatments for enuresis or spoke with their health care team about the enuresis. These data suggest that systematic assessment and intervention for nocturnal enuresis must be implemented in the follow-up care of children and adolescents with SCD.

Takotsubo cardiomyopathy following lightning strike

Lightning strike is the most common environmental cause of sudden cardiac death, but may also be associated with a myriad of injuries to various organ systems. Direct myocardial injury may be manifest as electrocardiographic alterations or elevation in cardiac-specific isoenzymes; however, significant electrical cardiac trauma appears uncommon. A case is presented of severe acute cardiomyopathy in a "Takotsubo" distribution causing cardiogenic shock following lightning strike in a previously healthy 37-year-old woman. Although rarely identified in this context, Takotsubo cardiomyopathy (also known as "transient left ventricular apical ballooning syndrome") is characterised by transient cardiac dysfunction, electrocardiographic changes that may mimic acute myocardial infarction and minimal release of cardiac-specific enzymes in the absence of obstructive coronary artery disease. The condition is associated with a substantial female bias (up to 90% of cases) in reported series, and despite occasionally dramatic presentations recovery of left ventricular function is almost universal over days to weeks. In rare instances, however, the syndrome has been associated with more catastrophic complications such as papillary muscle or cardiac free wall rupture, necessitating emergency surgical intervention to preserve life. In clinical practice, non-lethal lightning strike-induced cardiac injury is frequently associated with small elevations of cardiac isoenzymes without overt clinical sequelae; however, the incidence of silent myocardial mechanical dysfunction remains unknown. Cases such as the one presented highlight the potential for serious, albeit usually transient, cardiac sequelae from lightning strike injury and remind us that our mothers' advice to remain indoors during thunderstorms is probably worth heeding.

1H- and 13C-nmr assignments and structural determination of a novel glycoalkaloid from Solanum platanifolium

Four steroidal glycoalkaloids, solasonine [2], solamargine [3], khasianine [4], and ravifoline [5], with solasodine [1] as the aglycone moiety, have been isolated from Solanum platanifolium. The present study involved the characterization of the novel compound 5 by one- and two-dimensional nmr techniques and has also led to the unambiguous and total 13C- and 1H-nmr assignments of all of these steroidal glycoalkaloids and the direct elucidation of their glycosidic linkages.

Axillary artery damage following a closed fracture of the neck of the humerus--a case report

A case of intimal tearing of the axillary artery in association with a close fracture of the neck of the humerus is described. This is a rare injury and illustrates that vascular damage should never be assumed to be due to spasm. Exploration must be carried out because a mechanical vascular occlusion is most likely.

Cognitive dysfunction associated with COVID-19: Prognostic role of circulating biomarkers and microRNAs

COVID-19 is renowned as a multi-organ disease having subacute and long-term effects with a broad spectrum of clinical manifestations. The evolving scientific and clinical evidence demonstrates that the frequency of cognitive impairment after COVID-19 is high and it is crucial to explore more clinical research and implement proper diagnostic and treatment strategies. Several central nervous system complications have been reported as comorbidities of COVID-19. The changes in cognitive function associated with neurodegenerative diseases develop slowly over time and are only diagnosed at an already advanced stage of molecular pathology. Hence, understanding the common links between COVID-19 and neurodegenerative diseases will broaden our knowledge and help in strategizing prognostic and therapeutic approaches. The present review focuses on the diverse neurodegenerative changes associated with COVID-19 and will highlight the importance of major circulating biomarkers and microRNAs (miRNAs) associated with the disease progression and severity. The literature analysis showed that major proteins associated with central nervous system function, such as Glial fibrillary acidic protein, neurofilament light chain, p-tau 181, Ubiquitin C-terminal hydrolase L1, S100 calcium-binding protein B, Neuron-specific enolase and various inflammatory cytokines, were significantly altered in COVID-19 patients. Furthermore, among various miRNAs that are having pivotal roles in various neurodegenerative diseases, miR-146a, miR-155, Let-7b, miR-31, miR-16 and miR-21 have shown significant dysregulation in COVID-19 patients. Thus the review consolidates the important findings from the numerous studies to unravel the underlying mechanism of neurological sequelae in COVID-19 and the possible association of circulatory biomarkers, which may serve as prognostic predictors and therapeutic targets in future research.

Characterization of a polyclonal antibody to human pituitary tumor transforming gene 1 (PTTG1) protein

Pituitary tumor transforming gene 1 (PTTG1), recently cloned from human testis, is a potent oncogene that is expressed in most tumors. However, assessment of its potential value as a prognostic marker is dependent on the development of a suitable antibody. We have developed a rabbit polyclonal antibody, SK601, that is highly specific for the PTTG1 gene product using recombinant PTTG1 protein (24 kD) containing an N-terminal His(6) tag as the immunogen. The antiserum is capable of detecting recombinant PTTG1 protein in ELISA assays at a titer of 1:100,000. Use of the antibody as the probe in Western blotting analyses revealed a single band with the anticipated relative molecular weights of 52 kD from E. coli expressing the GST-PTTG1 recombinant protein, and 56 kD from COS-7 cells transfected with the PTTG1-GFP chimeric construct. A single band with a relative molecular weight of 28 kD was observed in extract of COS-7 cells transfected with PTTG1 cDNA. The antiserum immunoprecipitated a protein of relative molecular weight of 56 kD from the extracts of COS-7 cells transfected with the PTTG1-GFP chimeric construct. Immunohistochemical analysis of COS-7 cells transfected with this construct confirmed that the antibody detected and was specific for expressing the PTTG1-GFP recombinant protein. Screening of various normal human tissues (testis, ovary, and breast) by immunohistochemistry indicated that these tissues did not exhibit staining with the exception of testis, a tissue that had previously been shown to express PTTG1 mRNA. In contrast all of the tumor tissues (testicular tumor, ovarian tumor, and breast tumor) that were assessed exhibited intense staining. The results suggest that antiserum SK601 is highly specific for the PTTG1 protein and therefore should prove useful in further analysis of the expression and interactions of this protein, including its potential application as an immunohistochemical marker of human tumors.

Examining the immune response in sentinel lymph nodes of mice and men

Recently, it was recognized that an immune response develops along one of two major pathways. One leads to a destructive immune response (type 1), while the alternative leads to a nondestructive immune response (type 2). Our studies in animal models suggest that therapeutic vaccines induce a tumor-specific type 1 immune response while ineffective vaccines induce a type 2 response. These results have led us to examine the immune response in sentinel lymph nodes draining tumor vaccines of patients entered onto clinical trials for melanoma, breast and renal cell cancer.