Efficacy Assessment of Novel Methanimine Derivatives in Chronic Constriction Injury-Induced Neuropathic Model: An In-Vivo, Ex-Vivo and In-Silico Approach

The multicomponent etiology, complex clinical implications, dose-based side effect and degree of pain mitigation associated with the current pharmacological therapy is incapable in complete resolution of chronic neuropathic pain patients which necessitates the perpetual requirement of novel medication therapy. Therefore, this study explored the ameliorative aptitude of two novel methanimine imitative like (E)-N-(4-nitrobenzylidene)-4-chloro-2-iodobenzamine (KB 09) and (E)-N-(4-methylbenzylidene)-4-chloro-2-iodobenzamine (KB 10) in chronic constriction injury (CCI) of sciatic nerve induced neuropathic pain in rat model. Standard behavioral tests like dynamic and static allodynia, cold, thermal and mechanical hyperalgesia along with rotarod activity were performed at various experimental days like 0, 3, 7, 14 and 21. Enzyme linked immunosorbent assay (ELISA) on spinal tissue and antioxidant assays on sciatic nerve were executed accompanied by molecular docking and simulation studies. Prolonged ligation of sciatic nerve expressively induced hyperalgesia as well as allodynia in rats. KB 09 and KB 10 substantially attenuated the CCI elicited hyperalgesia and allodynia. They significantly reduced the biomarkers of pain and inflammation like Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in ELISA and while enhanced the GSH, SOD and CAT and diminished the MDA levels during antioxidant assays. KB 09 displayed -9.62 kcal/mol with TNF-α and -7.68 kcal/mol binding energy with IL-6 whereas KB 10 exhibited binding energy of -8.20 kcal/mol with IL-6 while -11.68 kcal/mol with TNF-α and hence both trial compounds ensured stable interaction with IL-6 and TNF-α during computational analysis. The results advocated that both methanimine derivatives might be novel candidates for attenuation of CCI-induced neuropathic pain prospects via anti-nociceptive, anti-inflammatory and antioxidant mechanisms.

Mechanistic efficacy assessment of selected novel methanimine derivatives against vincristine induced Neuropathy: In-vivo, Ex-vivo and In-silico correlates

Vincristine induced peripheral neuropathy (VIPN) is a serious untoward side effect suffered by cancer patients, which still lacks an adequate therapeutic approach. This study examined the alleviating potential of novel methanimine derivatives i.e. (E)-N-(4-nitrobenzylidene)-4-chloro-2-iodobenzamine (KB 9) and (E)-N-(2-methylbenzylidene)-4-chloro-2-iodobenzamine (KB 10) in VIPN. Vincristine was injected in BALB/c mice for 10 days to instigate nociceptive neuropathy. Dynamic and static allodynia, thermal (hot and cold) hyperalgesia were evaluated at 0, 5, 10 and 14 days using cotton brush, Von Frey filament application, hot plate test, acetone drop and cold water respectively. Tumour necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), lipid peroxide (LPO), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD) and reactive oxygen species (ROS) assays were performed to assess the efficacy of KB9 and KB10 against neuroinflammation and oxidative stress utilizing ELISA, immunohistochemistry and western blot analysis in brain and sciatic nerve tissues. Computational studies were executed to determine the stable binding conformation of both compounds with respect to COX-2 and NF-κB. Interestingly, both compounds substantially reduced protein expression related to neuroinflammation, oxidative stress (LPO, GST, SOD, CAT) and pain (NF-κB, COX-2, IL-1β and TNF-α). This molecular analysis suggested that the neuroprotective effect of KB9 and KB10 was mediated via regulation of inflammatory signaling pathways. Overall, this study demonstrated that KB9 and KB10 ameliorated vincristine induced neuropathy, through anti-inflammatory, anti-nociceptive and antioxidant mechanisms.

Exploring Amantadine Derivatives as Urease Inhibitors: Molecular Docking and Structure-Activity Relationship (SAR) Studies

This article describes the design and synthesis of a series of novel amantadine-thiourea conjugates (3a–j) as Jack bean urease inhibitors. The synthesized hybrids were assayed for their in vitro urease inhibition. Accordingly, N-(adamantan-1-ylcarbamothioyl)octanamide (3j) possessing a 7-carbon alkyl chain showed excellent activity with IC₅₀ value 0.0085 ± 0.0011 µM indicating that the long alkyl chain plays a vital role in enzyme inhibition. Whilst N-(adamantan-1-ylcarbamothioyl)-2-chlorobenzamide (3g) possessing a 2-chlorophenyl substitution was the next most efficient compound belonging to the aryl series with IC₅₀ value of 0.0087 ± 0.001 µM. The kinetic mechanism analyzed by Lineweaver–Burk plots revealed the non-competitive mode of inhibition for compound 3j. Moreover, in silico molecular docking against target protein (PDBID 4H9M) indicated that most of the synthesized compounds exhibit good binding affinity with protein. The compound 3j forms two hydrogen bonds with amino acid residue VAL391 having a binding distance of 1.858 Å and 2.240 Å. The interaction of 3j with amino acid residue located outside the catalytic site showed its non-competitive mode of inhibition. Based upon these results, it is anticipated that compound 3j may serve as a lead structure for the design of more potent urease inhibitors.

Living with Coronavirus (COVID-19): a brief report

The world will never be the same after the current COVID-19 pandemic. We may have to live with the coronavirus for a long time. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has resulted in a major burden on the global health system and economy. This report describes the current COVID-19 landscape and its socioeconomic implications. Despite the concerns for second waves of infection, gradual lifting of lockdown restrictions has occurred worldwide to relieve economic pressures and likely contributes towards possibly surging of outbreak although region wise variation exists due to several other biological factors, such as testing capacity and basic healthcare facilities among susceptible population within that region. Different prediction models have been put forth to forecast the spread of the current outbreak. However, it is challenging to perceive the precise changes happening in the real world as every time dynamics differ same as other epidemics cannot possibly be exactly superimposed to COVID-19. Currently, to decrypt the conundrum for effective antiviral drug against SARS-CoV-2 is in full swing. Due to high rate of mortality and it expeditiously spread is it decisive to understand the biological properties, clinical characteristics, epidemiology, evolution, pathogenesis for vaccine development and pathogenicity studies against the viral curb. Instant diagnostic and adequate therapeutics serve as a major intervention for the management of pandemic containment. Our study aims to analyze the impact of current measures and to suggest appropriate administrative strategic planning rather than to make somewhat authentic prediction in relation to the current scenario. Our predictive analysis study should be helpful against prevention, cure and control of the current outbreak of COVID-19 till the availability of cure or vaccine.

Effect of vitamin A as a neoadjuvant agent in chemotherapy and photodynamic therapy of Rhabdomyosarcoma cells

Combinational therapy is among the most used treatment modality's to increase cancer treatment efficacy. It may also reduce side effects, treatment time, and development of drug resistance. The effects of different analogues of vitamin A (VA) as neoadjuvant agent were observed in this study with chemotherapeutic drugs (doxorubicin and methotrexate) and photodynamic therapy (PDT) using 5-ALA and Photogem as photosensitizers in RD cells. The uptake time of photosensitizer was optimized by means of spectrophotometric measurements. Diode laser (λ = 635 nm ± 1 nm) was used as an illumination source for PDT. Responses of administered drugs were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. VA and its analogues exert prophylactic and therapeutic effects. Protective or antagonistic effects (CI > 1) were observed in each of the case. These results propose that the use of VA as a neoadjuvant agent in combinational therapeutic modalities may reduce the efficacy of cancer treatment protocols as well as the existing side effects. Thus, VA is not the successful drug for combinational therapies and under treatment cancer patients should try to avoid its use with oxidative stress induction therapies (e.g. PDT, Radiotherapy, chemotherapy).

An association between exposure to Middle East Respiratory Syndrome (MERS) and mortality rate of Coronavirus Disease 2019 (COVID-19)

OBJECTIVE

Our objective was to find an association between exposure of a population to Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and mortality rate due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) across different countries worldwide.

MATERIALS AND METHODS

To find the relationship between exposure to MERS-CoV and mortality rate due to SARS-CoV-2, we collected and analyzed data of three possible factors that may have resulted in an exposure of a population to MERS-CoV: (1) the number of Middle East Respiratory Syndrome (MERS) cases reported among 16 countries since 2012; (2) data of MERS-CoV seroprevalence in camels across 23 countries, as working with camels increase risk of exposure to MERS-CoV; (3) data of travel history of people from 51 countries to Saudi Arabia was collected on the assumption that travel to a country where MERS is endemic, such as, Saudi Arabia, could also lead to exposure to MERS-CoV.

RESULTS

We found a significantly lower number of Coronavirus disease 2019 (COVID-19) deaths per million (deaths/M) of a population in countries that are likely to be exposed to MERS-CoV than otherwise (t-stat=3.686, p<0.01). In addition, the number of COVID-19 deaths/M of a population was significantly lower in countries that reported a higher seroprevalence of MERS-CoV in camels than otherwise (t-stat=4.5077, p<0.01). Regression analysis showed that increased travelling history to Saudi Arabia is likely to be associated with a lower mortality rate due to COVID-19.

CONCLUSIONS

This study provides empirical evidence that a population that was at an increased risk of exposure to MERS-CoV had a significantly lower mortality rate due to SARS-CoV-2, which might be due to cross-protective immunity against SARS-CoV-2 in that population because of an earlier exposure to MERS-CoV.

An efficient synthetic approach toward a sporadic heterocyclic scaffold: 1,3-Oxathiol-2-ylidenes; alkaline phosphatase inhibition and molecular docking studies

We developed a simple and robust method for synthesis of 1,3-oxathiol-2-ylidene benzamides (4a-m) a sporadic class of heterocycles, by reacting freshly prepared aroyl isothiocyanates, with ethyl 2-chloroacetoacetate in presence of N-methylimidazole in dry acetonitrile. The synthesized compounds were explored for their inhibition against alkaline phosphatases and HeLa cancer cell lines. The results suggest that almost all the compounds possess good % inhibition against both enzymes, with compound 4m showing dual inhibition while 4g and 4i as potent and selective inhibitors of TNAP and c-IAP respectively. Structure activity relationship for the active members of series has been carried out based on molecular docking studies. The result of SAR shows the involvement of active inhibitors in H-bonding at various sites with different amino acid residues in addition to secondary metal ion interactions with Zn ions inside the active pocket of the enzyme. The π-π interactions between the 1,3-oxathiole ring and imidazole ring of His321 and His 317 further defines the dual mode of inhibition by compound 4m. These compounds also possess inhibition potential against cervical cell lines in the range of 2.42-69.03% with the maximum inhibition shown by the unsubstituted member 4a compared to the reference drug cisplatin.

Intermolecular interactions in antipyrine-like derivatives 2-halo-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)benzamides: X-ray structure, Hirshfeld surface analysis and DFT calculations

Based on experimental and computational data, a complex network of intermolecular interactions has been rationalized for antipyrine compounds.

Improving childhood tuberculosis detection and treatment through facility-based screening in rural Pakistan

SETTING

Many children with tuberculosis (TB) remain undiagnosed due to the absence of services, lack of child-friendly diagnostics and underappreciation of TB as a common cause of childhood illness.

OBJECTIVE

To show the impact of systematic verbal screening and contact tracing with appropriate management services on TB case finding in pediatric populations.

DESIGN

Between October 2014 and March 2016, children were verbally screened at the pediatric out-patient departments of four public hospitals in Jamshoro District, Pakistan. Children with symptoms or risk of TB were referred for clinical evaluation and free chest X-ray and bacteriological tests. Children with TB were started on treatment and their care givers asked to bring household members to the hospital for screening.

RESULTS

Over 105 000 children were verbally screened and 5880 presumptive childhood TB patients were identified; 1417 children (prevalence 1.3%) were diagnosed with TB; 43% were female. The median age was 5 years; 82% had pulmonary TB. An additional 390 children with TB were diagnosed through contact tracing. These activities resulted in a three-fold increase in pediatric TB case notifications.

CONCLUSION

Systematic verbal screening with clinical evaluation and free diagnostics can identify children with TB who may otherwise be missed in rural health settings.

Accreditation and evaluation of veterinary medical institutes - a Pakistani perspective

The Higher Education Commission of Pakistan (HEC) is an independent, autonomous and constitutionally established institution that provides primary funding for higher education in Pakistan, which it also oversees, regulates and accredits. According to the HEC Charter: 'the HEC of Pakistan may set up national or regional evaluation councils or authorise any existing council/or similar body to carry out accreditation of institutions including their departments, facilities and disciplines by giving them appropriate ratings'. At present, 14 accreditation bodies operate under the umbrella of the HEC. Five were established under the HEC's Quality Assurance Agency, while nine councils associated with the accreditation and evaluation of medical institutes are independent bodies that were extant before the HEC was created, and are recognised by the HEC. The authors will discuss the role of the Pakistan Veterinary Medical Council (PVMC), the accreditation of veterinary institutes and associated issues of concern. They suggest that the PVMC should adopt an unbiased approach to new and established veterinary institutes to attain uniform accreditation of all veterinary institutes throughout the country. In addition, the government should consult the accreditation councils and professional bodies before setting up new institutes. The authors also suggest that, instead of placing new veterinary institutes under the aegis of non-veterinary universities, they should be made sub-campuses of established veterinary universities. In time, they will emerge as established institutes in their own right.

Intra- and intermolecular hydrogen bonding and conformation in 1-acyl thioureas: an experimental and theoretical approach on 1-(2-chlorobenzoyl)thiourea

The vibrational analysis (FT-IR and FT-Raman) for the new 1-(2-chlorobenzoyl)thiourea species suggests that strong intramolecular interactions affect the conformational properties. The X-ray structure determination corroborates that an intramolecular N-H⋯OC hydrogen bond occurs between the carbonyl (-CO) and thioamide (-NH2) groups. Moreover, periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Extended N-H⋯SC hydrogen-bonding networks between both the thioamide (N-H) and carbamide (NH2) groups and the thiocarbonyl bond (CS) determine the crystal packing. The Natural Bond Orbital (NBO) population analysis demonstrates that strong hyperconjugative remote interactions are responsible for both, intra and intermolecular interactions. The Atom in Molecule (AIM) results also show that the N-H⋯Cl intramolecular hydrogen bond between the 2-Cl-phenyl ring and the amide group characterized in the free molecule changes to an N⋯Cl interaction as a consequence of crystal packing.

Synthesis, characterization and biological evaluation of N-(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyrazol-4-yl)benzamides

Comparison of active site residues of modelled h-GCAP with template h-PLAP.

Inhibition of polyadenylation reduces inflammatory gene induction

Cordycepin (3' deoxyadenosine) has long been used in the study of in vitro assembled polyadenylation complexes, because it terminates the poly(A) tail and arrests the cleavage complex. It is derived from caterpillar fungi, which are highly prized in Chinese traditional medicine. Here we show that cordycepin specifically inhibits the induction of inflammatory mRNAs by cytokines in human airway smooth muscle cells without affecting the expression of control mRNAs. Cordycepin treatment results in shorter poly(A) tails, and a reduction in the efficiency of mRNA cleavage and transcription termination is observed, indicating that the effects of cordycepin on 3' processing in cells are similar to those described in in vitro reactions. For the CCL2 and CXCL1 mRNAs, the effects of cordycepin are post-transcriptional, with the mRNA disappearing during or immediately after nuclear export. In contrast, although the recruitment of RNA polymerase II to the IL8 promoter is also unaffected, the levels of nascent transcript are reduced, indicating a defect in transcription elongation. We show that a reporter construct with 3' sequences from a histone gene is unaffected by cordycepin, while CXCL1 sequences confer cordycepin sensitivity to the reporter, demonstrating that polyadenylation is indeed required for the effect of cordycepin on gene expression. In addition, treatment with another polyadenyation inhibitor and knockdown of poly(A) polymerase α also specifically reduced the induction of inflammatory mRNAs. These data demonstrate that there are differences in the 3' processing of inflammatory and housekeeping genes and identify polyadenylation as a novel target for anti-inflammatory drugs.

A temporal-analysis-based pitch estimation system for noisy speech with a comparative study of performance of recent systems

In this paper, a new system of pitch estimation is presented. The system is designed to be robust to challenging noise conditions. This robustness to the presence of noise in the signal is achieved by developing a new representation of the speech signal, based on the operation of damped harmonic oscillators (DHOs), and temporal mode analysis of their output. The resulting representation is shown to possess qualities that are only gradually degraded in the presence of noise. A harmonic grouping based system is used to estimate the pitch frequency. This method is easily extended to simultaneously track the pitch of more than one speaker. In a series of experiments the accuracy and noise robustness of the proposed system was compared with that of a number of prominent pitch estimation and tracking systems. The results show that the proposed system's overall performance is much better than any of the other systems tested, especially in the presence of very large amounts of noise. Furthermore, the proposed system is comparatively inexpensive in terms of processing and memory requirements.

Cancer urinary bladder--5 year experience at Cenar, Quetta

BACKGROUND

Purpose of this study was to see the incidence, age, sex, geographical distribution, symptoms, personal habits, signs, histo-pathology, early diagnosis and management of cases of Cancer Urinary Bladder (Ca UB) in the patients coming to CENAR, Quetta, Pakistan.

METHODS

A retrospective study was conducted at CENAR for a period of 5 years from 1st Jan. 1993 to 31st Dec. 97, in which about 100 cases of cancer of urinary bladder were included, out of which 82 patients were male and 12 were females.

RESULTS

During our 5-year period of study, 3571 new cases of cancer were registered at CENAR, out of which 100 (2.8% of total No. of cases) were of Ca UB. Hence 20 new cases of Ca UB per year were registered at CENAR. The maximum number of cases was registered in 1996.

CONCLUSION

Our study concluded that Ca UB occurs more in male with a male female ratio of 4.5:1 and a high incidence after 40 years of age. No patient below 20 was reported. Histopathologically, Transitional Cell Carcinoma was dominating (75%). Other histological types seen were squamous cell carcinoma (4%), Adenocarcinoma (3%), UD (5%) and HPNA (10%). A considerable number of patients were using different preparations of tobacco (cigarette smoking (6%), Hubble-Bubble (5%) and Niswar (Snuff) (12%). The patients were mainly treated with Radiotherapy, because at the time of reporting they were already in stage II or beyond (97%). Some patients were also treated by surgery such as TUR, partial or radical cystectomy. A few patients (6%) also received chemotherapy.

Incidence of post transplant myelodysplasia/acute leukemia in non-Hodgkin's lymphoma patients compared with Hodgkin's disease patients undergoing autologous transplantation following cyclophosphamide, carmustine, and etoposide (CBV)

Secondary malignancies, particularly myelodysplasia (MDS), are serious events following high dose therapy with autologous stem cell support. We observed a higher frequency of secondary malignancies in patients with Hodgkin's disease (HD) than in patients with non-Hodgkin's lymphoma (NHL) undergoing high dose therapy with the same non-TBI conditioning regimen. Three hundred patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) were treated with cyclophosphamide, carmustine and etoposide and autologous stem cell support from 1986 through 1994. Median follow up of survivors is 3.9 years. Five-year survival is 51% for HD and 48% for NHL. Eleven patients developed second malignancies (9/150 treated for HD vs. 2/150 treated for NHL) a median of 2.4 years from transplantation and 5.2 years from initial diagnosis. Six patients had myelodysplasia or acute leukemia (MDS/AML) and 5 had lymphomas or solid tumors. Actuarial risk of MDS/AML at five years for patients transplanted for non-Hodgkin's lymphoma is 3% (95% CI 0.6-9.6%). HD patients had significantly different pretreatment characteristics than patients with NHL. A Cox model showed that greater number of prior relapses and prior radiation therapy were significant risk factors for the development of MDS/AML. These data suggest that CBV is associated with a lower risk of secondary MDS/AML than TBI containing regimens and that much of the risk is associated with the pre-transplantation therapy. The use of autotransplantation early in the course of therapy for relapsed lymphoma might prevent some cases of MDS/AML.

Auditory habituation in young and older adults: the verbal transformation effect

In 3 experiments, auditory massed repetition was used to examine age-related differences in habituation by means of the verbal transformation paradigm. Participants heard 10 words (5 high frequency and 5 low frequency), each presented 180 times, and they reported perceived changes in the repeated words (verbal transformations). In these experiments, older adults reported fewer illusory percepts than young adults. Older adults' loss of auditory acuity and slowing of processing, stimulus degradation (in young adults), and instructions biasing the report of these illusory percepts did not account for the fewer illusory percepts reported by the older adults. These findings suggest that older adults' reduced susceptibility to habituation arises from centrally located declines in the transmission of information within the word-recognition pathway. The discussion focuses on the implications that these age-related declines may have on word identification during on-line speech perception.

Auditory habituation in young and older adults: the verbal transformation effect

In 3 experiments, auditory massed repetition was used to examine age-related differences in habituation by means of the verbal transformation paradigm. Participants heard 10 words (5 high frequency and 5 low frequency), each presented 180 times, and they reported perceived changes in the repeated words (verbal transformations). In these experiments, older adults reported fewer illusory percepts than young adults. Older adults' loss of auditory acuity and slowing of processing, stimulus degradation (in young adults), and instructions biasing the report of these illusory percepts did not account for the fewer illusory percepts reported by the older adults. These findings suggest that older adults' reduced susceptibility to habituation arises from centrally located declines in the transmission of information within the word-recognition pathway. The discussion focuses on the implications that these age-related declines may have on word identification during on-line speech perception.

Disseminated Pseudallescheria boydii infection in a nonimmunocompromised host

We present a highly unusual case of pulmonary Pseudallescheria boydii infection in a nonimmunocompromised host with a cavitating mass lesion. The diagnosis was confirmed by open lung biopsy. The patient was treated at another institution with course of amphotericin B, considered an ineffective therapy for this infection, and presented to us with direct extension and invasion of the left atrial appendage and the pulmonary artery, followed by massive pulmonary embolization and hematogenous dissemination to the liver, spleen, kidney, pancreas, and brain.

Wegener's granulomatosis and alpha1-antitrypsin-deficiency emphysema: proteinase-related diseases

Wegener's granulomatosis (WG) and alpha1-antitrypsin (alpha1-AT)-deficiency emphysema are both uncommon disorders. A relationship may exist between these diseases involving the proteinase and antiproteinase balance in the lung. A case is presented of WG and alpha1-AT-deficiency emphysema occurring in the same patient. Previous studies concerning the correlation between abnormal alpha1-AT alleles and WG are discussed. Potential mechanisms for the relationship and recommendations for screening are given.

Meningioma in four patients with human immunodeficiency virus infection

We describe four patients infected with the human immunodeficiency virus (HIV) who had development of meningiomas. In contrast to those in the general population who have meningiomas, all our patients were young men; the mean age was 40 years (range, 32 to 50). Their risk behavior for HIV was homosexuality (three patients) and intravenous drug use (one patient). The CD4+ cell count in each of the three homosexual men was less than 50/microL and was 280/microL in the drug user. Imaging studies showed enhancing lesions in three of the patients. Although each of these meningiomas could have occurred in otherwise normal young to middle-aged men, we speculate that the meningiomas may have grown in these HIV-infected hosts because of either loss of immune function or dysregulation of cytokines.

Single-stage, bilateral, video-assisted thoracoscopic lung volume reduction surgery for end-stage emphysema

The reintroduction of lung volume reduction surgery has provided functional improvement for selected patients afflicted with end-stage emphysema. Evolution of the operation from a median sternotomy approach to the two-stage video-assisted thoracoscopic surgical technique in our experience has resulted in a faster return to full activity. Nineteen patients underwent video-assisted thoracoscopic lung volume reduction surgery between July 1995 and August 1997. The 12 men and 7 women in the study had an average age of 63.7 years. All patients were evaluated preoperatively with computed tomography of the chest, radionuclide lung perfusion scan, left ventricular stress test, right heart catheterization, and a monitored rehabilitation program. In 15 patients the operation was performed as a bilateral single-stage procedure. The operation involved resection of wedges from the upper lobes and in 10 of these patients from the lower lobes as well. In all patients the estimated operative blood loss was less than 150 ml. The mean operative time was 177 minutes (range 115-235 minutes). The mean length of hospital stay was 10.8 days (median 11 days, range 5-24 days). At 2 to 3 months' follow-up increases were noted in the FEV1 (51%), PaO2 (27%), and 6-minute walk distance (18%); and there was a decrease in total lung capacity and respiratory volume. No significant change was observed in carbon monoxide diffusion in the lung. Morbidity included persistent air leaks in three patients and refractory supraventricular tachyarrhythmia in one. There were no perioperative deaths. We therefore recommend this technical modification to reduce operating time and blood loss without compromising surgical exposure or outcome.

A prospective, controlled study of Helicobacter pylori seroprevalence in coronary artery disease

OBJECTIVE

Recent studies have suggested that chronic infections may be a risk factor for coronary artery disease. The aim of this study was to determine whether Helicobacter pylori (H. pylori) infection was an independent risk factor for coronary artery disease.

METHODS

A total of 179 patients undergoing coronary angiography for suspected coronary artery disease were prospectively studied. Angiograms were read by experienced invasive cardiologists blinded to the results of H. pylori serology, which was determined by a validated multiwell ELISA assay.

RESULTS

A total of 121 patients (68%) had evidence of coronary artery disease, whereas 58 patients (32%) had normal coronary angiograms. Of the 121 patients with coronary artery disease, 29 had single vessel disease, 39 had double vessel disease, and 53 had triple vessel disease, respectively. There was no significant difference in seroprevalence of H. pylori infection in patients with and without coronary artery disease (p = 0.63). The odds ratio (after adjustment for other known risk factors) for coronary artery disease in H. pylori-infected subjects was 0.45 (95% CI = 0.15, 1.37; p = 0.107). In patients with coronary artery disease, H. pylori infection did not increase the likelihood of severe disease (odds ratio for triple vessel disease = 0.53; 95% CI 0.18, 1.60; p = 0.201).

CONCLUSION

H. pylori infection rates are similar in patients with normal and abnormal coronary arteries, and infection with H. pylori is not an independent risk factor for coronary artery disease. In patients who have coronary artery disease, H. pylori infection is not a risk factor for more severe disease. These data argue against a causal role for H. pylori in the pathogenesis of coronary artery disease.

Infection of human papillomavirus (HPV) and Epstein-Barr virus (EBV) and p53 expression in human esophageal carcinoma

To clarify the role of high risk human papillomavirus (HPV 16, 18 and 33) and Epstein-Barr virus (EBV) infection in esophageal carcinogenesis in relation to expression of mutated p53 antioncogene, we used PCR to amplify DNA sequences of these viruses and immunohistochemistry to detect p53 expression in formaline-fixed, paraffin embedded blocks including 12 normal esophageal and 27 esophageal carcinoma specimens. HPV and EBV DNA were found in 25% and 0% of normal esophageal tissues and in 63% and 7% of esophageal carcinoma specimens, respectively. p53 expression was shown in 59% of esophageal carcinoma specimens only. HPV infection rate was significantly higher in specimens from carcinoma cases as compared with normal esophageal tissue obtained from cases without carcinoma. No correlation was found between p53 expression and/or the presence of viral DNA (HPV/EBV) in regard to the age and sex of the patient, histological grade, histological stage, depth of invasion, lymph node involvement, distant metastasis and the location of the tumors, p53 expression was almost equally distributed between HPV positive and negative carcinoma cases. Our results suggest that most of the esophageal carcinomas are associated with HPV infection and p53 mutations and there is no inverse correlation between HPV and infection and expression of p53 in esophageal carcinoma.

Formulas and tables for the determination of sample sizes and power in clinical trials for testing differences in proportions for the matched pair design: a review

This paper is a compendium of exact and asymptotic formulas and tables for calculating the sample size in a clinical trial for a matched-pair design involving a dichotomous outcome. Formulas for calculating power given the sample size are also given.

Formulae and tables for the determination of sample sizes and power in clinical trials for testing differences in proportions for the two-sample design: a review

This paper is a compendium of exact and asymptotic formulae and tables for estimating the sample size in a clinical trial with two treatment groups and a dichotomous outcome. The paper provides separate formulae for equal and unequal treatment group sizes, formulae for the calculation of power given the sample size, and complete references for all formulae and tables cited.

On analysis of epidemiological data involving a 2 x 2 contingency table: an overview of Fisher's exact test and Yates' correction for continuity

Fisher's exact test and Pearson's chi-square with continuity correction are frequently employed in the analysis of epidemiological data involving a 2 x 2 contingency table. This paper reviews the concepts and controversies underlying these procedures and discusses their appropriateness and adequacies in analyzing such data. Other related procedures such as unconditional exact tests and randomized and mid-p tests including some generalizations to a r x c table are also briefly reviewed.

A note on confidence intervals for the hypergeometric parameter in analyzing biomedical data

Some methods of constructing confidence intervals for the probability of success in a hypergeometric distribution are described and illustrated with examples. To assist the readers in implementing the procedures, pertinent information on special tables and computer programs is provided that can be readily employed with little or no additional computation.