Aqueous-based polymeric dispersion: face-centered cubic design for the development of atenolol gastrointestinal therapeutic system

The main objective of the study was to use the statistical response surface methodology to evaluate the effect of formulation variables and their interaction on drug release in atenolol gastrointestinal therapeutic system (GITS) development coated with cellulose acetate (CA) pseudolatex system. A three-factor, three-level, face-centered design was employed to evaluate the quadratic response surface, and to achieve the desired response in atenolol delivery. Coating was achieved by spraying plasticized CA pseudolatex on atenolol bilayered tablets in a Uni-Glatt fluidized-bed coater. The independent variables were orifice size (X1), percent coating weight gain (X2) and Carbopol 934P (X3). The response variable (Y1) was time for 50% (t50%) drug dissolution with a constraint on cumulative percent released in 24 hr (Y2). The polynomial equation obtained was Y1 = 61.88 - 3779.8X1 + 1.89X2 - 3.95X3 - 266.87 X1X2 - 1675X1X3 + 0.07X2X3 + 215123X1(2) + 0.06X2(2) + 0.10X3(2). Contour and response plots were used to relate the independent and dependent variables. The optimization procedure predicted a t50% of 10.83 hr with 92% atenolol release in 24 hr when orifice size (X1), percent coating weight gain (X2), and Carbopol 934P (X3) were 0.014 in., 13%, and 20 mg, respectively. Preparation and testing of optimized formulation showed a good correlation between the predicted and observed values.

Elevated levels of IL-8 in dengue hemorrhagic fever

Dengue virus causes dengue fever, a mild febrile illness, and at times dengue hemorrhagic fever (DHF), a severe illness the pathogenesis of which is not fully understood. Given the crucial roles played by interleukin-8 (IL-8) as a chemoattractant cytokine and in inflammatory processes, levels of circulating IL-8 in the sera and IL-8 mRNA in the peripheral blood mononuclear cells (PBMC) were measured in 99 patients of a recent dengue epidemic that occurred in India in 1996 and in 21 normal healthy controls. Twenty-six of the patients had dengue fever (DF) and the remaining 73 were diagnosed as having different grades of DHF. All the control normal sera were negative for IL-8, so were their PBMC for IL-8 mRNA. Increased levels of IL-8 in the sera and IL-8 mRNA in their PBMC were observed in patients with severe illness of DHF grades III and IV. Only two out of 26 patients of DF and one out of 10 DHF grade I patient were positive for IL-8 and all three deteriorated to DHF grade IV within 24 hr. All six patients of DHF grade IV who died had higher serum level of IL-8 above 200 pg/ml, the highest being 5,568 pg/ml in one patient; the presence of mRNA for IL-8 was very high in all patients. A striking correlation was observed between increased levels of IL-8 and severe DHF, with greater levels in patients with increased grade of the disease and death. These results suggest that IL-8 may have an important role and may be an indicator of increasing severity of the disease and death.

Short-course ceftriaxone therapy in spontaneous bacterial peritonitis

Forty patients with spontaneous bacterial peritonitis, three of whom had complicating acute hepatitis syndrome, eight late-onset hepatic failure, and 29 with cirrhosis, were treated with ceftriaxone 2 g intravenously once daily for 5 days. Ascitic fluid culture was positive in 28 patients, with Escherichia coli and Klebsiella as common isolates. All the bacteria isolated were sensitive to ceftriaxone except Enterococcus faecalis, which was isolated in a cirrhotic patient. All culture-positive patients sensitive to ceftriaxone showed bacteriological cure and 26 (65%) patients showed cytological cure after 48 hours of treatment. A total of 95% were cured of their infection after 5 days of treatment. Twelve (30%) patients died during hospitalisation after documented cure of their spontaneous bacterial peritonitis (renal failure, gastrointestinal bleed and cerebral oedema were the primary causes of death). Infection-related mortality due to Pseudomonas septicaemia was seen in one cirrhotic patient.

The prevalence of cardiac valvular insufficiency assessed by transthoracic echocardiography in obese patients treated with appetite-suppressant drugs

BACKGROUND

After case reports of cardiac-valve abnormalities related to the use of appetite suppressants were published, we undertook a study to determine the prevalence of the problem using transthoracic echocardiography.

METHODS

We examined patients who had taken dexfenfluramine alone, dexfenfluramine and phentermine, or fenfluramine and phentermine for various periods. We enrolled obese patients who had taken or were taking these agents during open-label trials from January 1994 through August 1997. We also recruited subjects who had not taken appetite suppressants and who were matched to the patients for sex, height, and pretreatment age and body-mass index. The presence of cardiac-valve abnormalities, defined by the Food and Drug Administration and Centers for Disease Control and Prevention as at least mild aortic-valve or moderate mitral-valve insufficiency, was determined independently by at least two cardiologists. Multivariate logistic-regression analysis was used to identify factors associated with cardiac-valve abnormalities.

RESULTS

Echocardiograms were available for 257 patients and 239 control subjects. The association between the use of any appetite suppressant and cardiac-valve abnormalities was analyzed in a final matched group of 233 pairs of patients and controls. A total of 1.3 percent of the controls (3 of 233) and 22.7 percent of the patients (53 of 233) met the case definition for cardiac-valve abnormalities (odds ratio, 22.6; 95 percent confidence interval, 7.1 to 114.2; P<0.001). The odds ratio for such cardiac-valve abnormalities was 12.7 (95 percent confidence interval, 2.9 to 56.4) with the use of dexfenfluramine alone, 24.5 (5.9 to 102.2) with the use of dexfenfluramine and phentermine, and 26.3 (7.9 to 87.1) with the use of fenfluramine and phentermine.

CONCLUSIONS

Obese patients who took fenfluramine and phentermine, dexfenfluramine alone, or dexfenfluramine and phentermine had a significantly higher prevalence of cardiac valvular insufficiency than a matched group of control subjects.

Effect of menthol on permeability of an optically active and racemic propranolol across guinea pig skin

The effect of menthol on the percutaneous penetration of S(-)-propranolol (SPL) and racemic form of propranolol (RSPL) was investigated in vitro using excised abdominal skin of guinea pig. In the presence of menthol, the permeability coefficient of SPL was high compared with that of RSPL. The enhancement factors for SPL and RSPL were 2.12 and 0.85, respectively. The lag times for SPL and RSPL were reduced considerably in the presence of menthol compared to those for control (without enhancer). The present findings suggest the enantio-selective permeation of SPL across the guinea pig skin in the presence of menthol.

Carcinoma in a bladder diverticulum: the place of diverticulectomy

A carcinoma within a vesical diverticulum represents a therapeutic challenge because it has generally a poor prognosis, and unambiguous guidelines for its therapy are not at hand. The authors report their experience with two low-grade single and confined tumours which were treated by simple diverticulectomy. Both patients remained tumour-free after 2 and 4 years of follow-up, respectively. The literature has been reviewed to assess the state of the art approach for such tumours. Whereas simple diverticulectomy may be indicated in selected, confined cases, an aggressive approach combining surgery and radio- and/or chemotherapy is recommended in the majority of vesical diverticulum tumours.

In vivo expression of the beta-glucoside (bgl) operon of Escherichia coli occurs in mouse liver

An Escherichia coli DNA fragment was identified that contained part of the beta-glucoside (bgl) operon. This fragment was identified because it contained a promoter that was responsible for the expression of a reporter gene, the chloramphenicol acetyltransferase gene, in a mouse liver during bacterial infection but not when a bacterial clone was grown in vitro. This fragment contained a promoter and a rho-independent transcription terminator which were flanked by the 3' end of bglG and the 5' end of bglF. Reverse transcription-PCR confirmed that cat-specific mRNA was produced in infected mouse liver but not in vitro. mRNA encoding the positive regulator of the bgl operon, bglG, also was detected in mouse liver infected with an E. coli strain. These results demonstrated that expression of the bgl operon occurs in infected mouse liver and suggests a unique role for this operon in vivo.

Racemate and enantiomers of ketoprofen: phase diagram, thermodynamic studies, skin permeability, and use of chiral permeation enhancers

The role of intrinsic and extrinsic factors on transport of a chiral drug through the skin was studied. Ketoprofen (KP) was chosen as a model chiral drug. A possible relationship between the melting characteristics and the flux values of S- and RS-KP was investigated. The potential use of chiral enhancers, menthol and linalool, was also investigated. Thermal analyses were carried out for individual enantiomers and the racemate of KP. The melting temperature of each enantiomer was 22 degreesC lower than that of the racemic compound. Peak temperatures from the melting endotherms were plotted as a function of enantiomeric composition to give the binary phase diagram. The phase diagram suggested the presence of a racemic compound, and it was verified by calculations of the liquidus curve in the dystectic region using reported methods. Powder X-ray diffraction studies also confirmed that the racemate of KP is a racemic compound. The permeability of individual enantiomers and the racemate of KP through mice skin was determined in vitro using side-by-side diffusion cells. Transfer of R- and S-KP from aqueous solutions of both the racemate and pure enantiomer showed no significant differences in the rates of permeation, indicating that the rate of transfer of KP across the mice skin from these solutions was independent of the stereochemistry of the drug. No evidence of racemization during the transfer process was observed. The permeation-enhancing ratio of linalool was higher, but not significant, than that of l-menthol. The predicted ratio of enantiomer to racemate flux through the skin by the MTMT concept (1. 97) is in close agreement with the experimentally determined ratio (1.79) across mouse skin.

Vascular endothelial growth factor and nitric oxide synthase expression in human lung cancer and the relation to p53

Vascular endothelial growth factor (VEGF) expression and mutations of cancer-related genes increase with cancer progression. This correlation suggests the hypothesis that oncogenes and tumour suppressors regulate VEGF, and a significant correlation between p53 alteration and increased VEGF expression in human lung cancer was reported recently. To further examine this hypothesis, we analysed VEGF protein expression and mutations in p53 and K-ras in 27 non-small-cell lung cancers (NSCLC): 16 squamous cell, six adenocarcinomas, one large cell, two carcinoids and two undifferentiated tumours. VEGF was expressed in 50% of the squamous cell carcinomas (SCC) and carcinoids but none of the others. p53 mutations occurred in 14 tumours (52%), and K-ras mutations were found in two adenocarcinomas and one SCC; there was no correlation between the mutations and VEGF expression. As nitric oxide also regulates angiogenesis, we examined NOS expression in NSCLC. The Ca2+-dependent NOS activity, which indicates NOS1 and NOS3 expression, was significantly reduced in lung carcinomas compared with adjacent non-tumour tissue (P < 0.004). Although the Ca2+-independent NOS activity, which indicates NOS2 expression, was low or undetectable in non-tumour tissues and most carcinomas, significant activity occurred in three SCC. In summary, our data do not show a direct regulation of VEGF by p53 in NSCLC. Finally, we did not find the up-regulation of NOS isoforms during NSCLC progression that has been suggested for gynaecological and breast cancers.

Detection of Staphylococcus aureus in milk by use of polymerase chain reaction analysis

OBJECTIVE

To evaluate polymerase chain reaction (PCR) analysis for detection of Staphylococcus aureus (nuc gene) in fresh and formalin-preserved milk.

SAMPLE POPULATION

Samples from 80 lactating sheep and 100 lactating dairy cows.

PROCEDURE

4 lactating sheep were inoculated with S aureus by intramammary infusion. A set of primers specific for the nuc gene of S aureus was used to develop a PCR technique, and modification of the rapid boil method was used to isolate bacterial DNA. Milk was obtained from experimentally infected sheep before and after infusion with S aureus, and from the 100 cows and remaining 76 sheep. Samples were screened by bacteriologic culture and PCR. To validate the PCR assay, S aureus or other pathogens were added to distilled water and "normal" sheep milk samples, with and without formalin.

RESULTS

The PCR assay was 100% specific for S aureus when known negative and positive samples were tested. Sensitivity was 100% for samples with added S aureus or other pathogens. Sensitivity was lower for samples obtained from experimentally infected sheep, but increased from 53% to 90% with increased washing of target DNA.

CONCLUSIONS

The PCR technique based on the nuc gene is able to detect S aureus in sheep milk yields results faster than does traditional culturing, is highly specific, and is able to detect S aureus in formalin-fixed milk samples.

CLINICAL RELEVANCE

The assay is particularly suitable for analysis of samples shipped or stored without refrigeration. Although antibiotics in milk may inhibit growth in culture, they should not affect the results of the PCR assay.

Aqueous based polymeric dispersion: Plackett--Burman design for screening of formulation variables of atenolol gastrointestinal therapeutic system

Bilayered osmotically controlled Gastrointestinal Therapeutic System of atenolol has been obtained by using cellulose acetate pseudolatex prepared by polymer emulsification method. Various factors such as orifice size, coating thickness, amount and nature of polymeric excipients, and amount of osmotic agent influence the drug release from GITS. Therefore, in the present study a 7-factor, 12-run Plackett-Burman screening design was employed to evaluate the formulation variables for atenolol GITS coated with CA pseudolatex. The variables studied were orifice size, %coating weight gain, amounts of sodium chloride. Polyox N80 and 303, and Carbopol 934P and 974P on drug release. The screening design has revealed that orifice size, %coating weight gain and amount of Carbopol 934P have prominent influence on in-vitro atenolol release. The response variable was cumulative percent atenolol released (Y) in 24 h with constraints on percent release at 2, 6, 12 and 18 h. The polynomial equation obtained was Y24 = 149.82 - 0.13 X1 - 0.34X2 + 0.06X3 - 0.13X4 - 0.23X5 - 76.25X6 - 2.46X7. The results indicated that the drug release under constrained conditions was influenced by the factors with decreasing order of importance as %coating weight gain > Carbopol 934P > Polyox N80 > Carbopol 974P > Polyox 303 > amount of sodium chloride > orifice size.

Pure mucinous carcinoma of the breast: a clinicopathologic correlation study

BACKGROUND

Pure mucinous carcinoma (PMC) of the breast has a better prognosis than does invasive ductal carcinoma not otherwise specified and is more prevalent in older patients. We investigated the correlation between prognostic indices and clinical outcome in this histologic subset.

METHODS

A retrospective review was done of patients with PMC treated between 1989 and 1996. Demographic data, pathologic indices of prognosis, axillary nodal status, and outcome were assessed.

RESULTS

Out of 6083 cases of breast carcinoma, 30 were PMC. Only 3 of 25 (12%) axillary dissections were positive. The average age of the group with positive nodes was 57 years, as compared to 69.5 years (95% CI; 63.24-75.76) in the group with negative nodes. All the tumors with positive nodes were aneuploid and had a high nuclear grade, compared to a 31.25% aneuploidy rate in the group without nodal disease (P = .058). Negative ER receptors were found in only 2 of 20 (10%) of the patients tested. Both had axillary disease (P = .016). Tumor size did not correlate with axillary metastasis. Two of the 29 patients died from unrelated diseases. The other 27 patients are alive with no evidence of disease.

CONCLUSIONS

Axillary nodal disease is rare in PMC and correlates with a younger age, aneuploidy, high nuclear grade, or a negative ER receptor status. Sentinel lymph node biopsy may help identify the need for axillary dissection.

Risperidone in Indian patients with schizophrenia

Conventional antipsychotic agents are not effective against negative symptoms of schizophrenia and are also noted for their extrapyramidal side effects. Risperidone is a noval antipsychotic agent whose dual antagonism of dopamine and serotonin receptors is believed to underlie its efficacy against negative symptoms and the low incidence of extrapyramidal side effects. An open, non-comparative study of seven weeks duration was performed to evaluate risperidone in the treatment of schizophrenia in Indian patients. Previous antipsychotic therapy was discontinued for a week before risperidone therapy was initiated. At the end of six weeks of risperidone therapy, clinical improvement (≥ 20% reduction in total score on positive and negative syndrome scale for schizophrenia (PANSS;; was shown by 128 (87.7%) of the 146 evaluable patients. Statistically significant reduction (p < 0.05) occurred in the total score of this scale and in the subscale scores for positive, negative and general psychopathology symptoms and in the clinical global impression severity score. The number of patients with adverse experiences were 108 (65.5%) at baseline and 120 (72.7%) at the end of risperidone therapy. Extrapyramidal symptoms, seen in 65 (39.4%) patients compared to 22 (13.3%) patients at baseline, were largely mild to moderate in intensity.

Arthritis and HLA-B27 in native North American tribes

Whereas it is clear that HLA-B27 is increased in many North American natives, the prevalence varies a great deal. There is still a paucity of data on a large number of tribes. There is, however, a suggestion that HLA-B27 positive prevalence follows cultural/linguistic groupings. Reactive arthritis, sacroiliitis, and ankylosing spondylitis also appear to be increased in these people, but their relationship to HLA-B27 and possibly additional genetic predisposing factors is far from clear. Given these data and the known association of infectious agents, more extensive studies are warranted, especially in those tribes with a large enough population to achieve statistical significance.

Hiatal hernia in achalasia

Barium esophagograms of 89 patients out of 110 with manometrically proven achalasia were reviewed. Only four (4.4%) patients showed association of hiatal hernia, indicative of its rare occurrence. Presence of hiatal hernia, is said to have less likelihood of associated achalasia but this association does exist as per our report and that of others.

Allelic deletion analysis of the FHIT gene predicts poor survival in non-small cell lung cancer

The fragile histidine triad (FHIT) gene at chromosome 3p14.2 is a candidate tumor suppressor gene linked to cancers of the lung, breast, colon, pancreas, and head and neck. Reports of frequent allelic deletion and abnormal transcripts in primary lung tumors plus recent evidence that it is targeted by tobacco smoke carcinogens suggest that it plays an important role in lung carcinogenesis. Non-small cell lung carcinoma still maintains a poor 5-year survival rate with the stage of disease at presentation as a major determinant of prognosis. We examined for allelic deletion at the FHIT locus in a series of 106 non-small cell lung carcinomas for which a full clinical, epidemiological, and 5-year survival profile was available. We found an allelic deletion frequency of 38% at one or two intragenic microsatellites. Allelic deletion of FHIT was related to tumor histology with 4 of 20 adenocarcinomas (20%) displaying loss of heterozygosity (LOH) compared with 12 of 22 (55%) nonadenocarcinomas (P = 0.03). We found that 63% of tumors with LOH of FHIT also had p53 missense mutations whereas only 26% with LOH had wild type p53 negative sequence (P = 0.02). We also found a significant trend toward poorer survival in patients with LOH of at least one locus of the FHIT gene (log rank, P = 0.01). This survival correlation is independent of tumor stage, size, histological subtype, degree of differentiation, and p53 mutation status. Our data support the hypothesis that the loss of the FHIT contributes to the molecular pathogenesis of human lung cancer and is an indicator of poor prognosis.

Epidemiology of childhood tuberculosis in a hospital setting

A study of two hundred cases of tuberculosis over a span of two years was carried out at the pediatric department of a hospital in Islamabad. The diagnosis was based upon history, clinical examination, chest and other relevant radiography, Mantoux test, erythrocyte sedimentation rate (ESR) and where necessary cerebrospinal, pleural and ascitic fluid examinations and lymph gland histopathology were done. An equal number of male and female children upto 12 years of age were enrolled. The children usually presented with fever, cough, weight loss or failure to thrive and pallor. The most commonly affected age group was between 2-5 years and pulmonary tuberculosis was the most frequent diagnosis followed by tuberculous adenitis.

Solid-state stability assessment of controlled release tablets containing Carbopol 971P

A tablet formulation containing dyphylline, Carbomer, magnesium stearate, talc and lactose was prepared by the direct compression method. The objective of the study was to assess the stability of these tablets after subjecting them to exaggerated conditions of temperature (4, 25, 37, 45 and 55 degrees C) and humidity (37 degrees/11%RH, 37 degrees/51%RH and 37 degrees C/91%RH). The samples were analyzed for crystalline, thermal and dissolution changes with time for a period of 12 months using X-ray diffractometry (XRD), differential scanning calorimetry (DSC) and U.S.P. Dissolution Apparatus 2. Moisture sorption studies of all tablets indicated sorption of large amounts of moisture at 37 degrees C/91%RH. The fit factors, f1 andf2, were calculated and used to compare the dissolution profiles. The results showed increased f1 and decreased f2 values at higher humidity, while the samples were fairly stable at lower humidity and at all temperatures studied. Powder XRD patterns of tablets showed a change in crystallinity at higher humidity. The thermal and crystalline data indicated that the change in dissolution behavior at higher humidity may be due to the conversion of dyphylline to its hydrate form.