Probable cutaneous allergic response to subcutaneous heparin--a case report

Heparin is a heterogeneous mixture of sulfated mucopolysaccharides, commonly used injectable anticoagulant. It is known to cause cutaneous adverse reactions like eczema, erythematous plaques, exfoliative dermatitis and tissue necrosis. We report a case of probable cutaneous allergic response caused by injection of heparin with an established causality and severity. The reaction developed after stopping the drug therapy and after the patient had already been discharged. Since heparin is a widely used drug and this reaction can manifest even after the drug therapy has ceased, thorough counseling of the patient is mandatory.

Effect of mangiferin on mitochondrial energy production in experimentally induced myocardial infarcted rats

Mangiferin, from the leaves of Mangifera indica Linn., has been suggested as useful in the treatment of cardiovascular disorders. In the present study this drug was examined on the alteration of cardiac energy metabolism in isoproterenol (ISPH) administered myocardial infarcted rats. ISPH (20 mg/kg b.w.), which was administered s.c. twice at an interval of 24 h, caused a significant decrease in the activities of TCA cycle enzymes and antioxidant defense enzymes with a concomitant increase in the lipid peroxidation of heart mitochondria in rat model. The ATP production and the oxidation of succinate in State 3 and 4 decreased significantly in the cardiac mitochondria of ISPH administered rats. These functional alterations were supported by severe modifications in mitochondrial ultrastructure. Pretreatment with mangiferin (100 mg/kg b.w. i.p.) for 28 days prevented these mitochondrial alterations, oxidation with energy metabolism and restored the TCA cycle enzyme activities to near normal values following ISPH administration. The structural integrity of the heart was protected by mangiferin in ISPH administered rats when compared to the untreated controls. The present findings suggest that the protective effect of mangiferin can be attributed to its reducing effect on oxidative damage and activation of mitochondrial energy metabolism. These results could be useful to study and understand the cellular events involved in this cardioprotective mechanism of mangiferin. Our studies of mangiferin on heart failure may have important implication for future therapeutic approaches involving in the prevention of cardiovascular diseases.

Cardioprotective effect of mangiferin on isoproterenol induced myocardial infarction in rats

Isoproterenol (ISPH) induced myocardial infarction was confirmed by disturbances in serum and heart tissue marker enzymes such as lactate dehydrogenase (LDH), creatine phospho kinase (CPK), aspartate transaminase (AST) and alanine transaminase (ALT), increased level of lipid peroxidation and histopathological changes in the heart of ISPH administered rats. Pretreatment with mangiferin (10 mg/100 g body weight) for 28 days was found to ameliorate the effect of ISPH-induced pathological changes, reduced the lipid peroxide formation and retained the myocardial marker enzyme activities at near normal level. The above results indicate the cardioprotective effect of mangiferin against ISPH-induced myocardial infarction in rats.

Study of histamine wheal suppression by dexamethasone with and without iontophoresis

BACKGROUND

Iontophoresis increases the penetration of drugs into the skin by electric current. The ability of topical steroids to reduce the size of the histamine wheal was used to assess the efficacy of topical dexamethasone delivered with and without iontophoresis.

AIM

To determine the wheal suppressing ability of dexamethasone delivered with and without iontophoresis.

METHODS

A template with three squares of 3x3 cm was placed on both forearms of 20 volunteers and the edges marked. A gauze piece soaked in 2 ml of dexamethasone solution was placed on the flexor aspect of the left forearm and the electrode, an aluminum foil was placed on it and connected to the negative pole (since dexamethasone is negatively charged). An electric current was passed for 15 minutes. Similarly, on the right forearm, a dexamethasone soaked gauze piece was placed without iontophoresis. Histamine wheal suppression was assessed at the end of 30 min, 1 hr and 2 hrs, on both sides. Statistical analysis was done using an independent t-test.

RESULTS

There was a statistically significant difference in wheal suppression at 30 min (p=0.006) on the left hand where iontophoresis was used.

CONCLUSION

Our experiment showed that topical dexamethasone with iontophoresis has the maximum effect at the end of 30 minutes and is more effective than dexamethasone without iontophoresis.

Needles and needleless devices for infusion of anti-haemophilic factor concentrate: impact on protein structure and function

A poor response to the infusion of anti-haemophilic factor (AHF) concentrates used to control acute bleeding or prevent haemorrhage during surgery may have many causes, including the lack of functional activity of the infused protein concentrate. It is generally recommended to follow the manufacturers' instructions when administering the factor intravenously. For convenience, infusion sets with 23 gauge butterfly needles are packaged with the major brands of AHF concentrate. In hospitals, blunt connectors for i.v. infusion are becoming more prevalent to reduce the risk of needle stick injuries to both patients and hospital staff. The integrity of AHF infused using such devices has not been examined. We examined the possibility that passage of complex proteins such as AHF through such devices may result in alteration of the protein, rendering it inactive. The results presented here suggest that this is not the case; neither the structure nor the function of AHF protein products was adversely affected by the use of the needleless transfer device (NTD) or the needle types and sizes commonly used in clinical practice. Samples of factor VIII and factor IX AHF concentrate were passed through the B-D Blunt Plastic Cannula or 23, 27 and 30 gauge needles. No significant changes in electrophoretic mobility or coagulation activity were detected. Samples generally showed slightly increased coagulation activity when compared with the control in which the sample was passed directly out of the syringe with no device attached. These data indicate that the NTD and various needle gauges are acceptable for the infusion of AHF concentrate in a clinical setting. Furthermore, the use of small gauge needles has advantages that may improve adherence to rigorous factor replacement programmes.

Determination of 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP) and its metabolite 2-hydroxyamino-PhIP by liquid chromatography/electrospray ionization-ion trap mass spectrometry

2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most abundant heterocyclic aromatic amine found in cooked meat. It is metabolically activated by the human cytochrome P450 enzymes to form the carcinogenic metabolite N2-OH-PhIP. PhIP has been found to induce tumors in rats and is a suspected human carcinogen. In the present work, we have developed and validated a liquid chromatography-electrospray ionization/ion trap mass spectrometry (LC-ESI/ITMS) method for the determination of PhIP and N2-OH-PhIP. PhIP was incubated with microsomes prepared from the human liver; the PhIP and N2-OH-PhIP formed were isolated from the biomatrices by solid-phase extraction using C18 cartridges, with recoveries greater than 86%. Subsequently, the products were separated on a microbore reversed-phase C18 liquid chromatograph coupled to an ESI-ITMS. The ESI interface and the ITMS were tuned for various parameters, and data acquisition was performed in selective ion monitoring mode. The detection limit of PhIP and N2-OH-PhIP was 1 and 10 pg, respectively. The method is highly sensitive and selective, has simple sample preparation protocols, and should be applicable to the study of the metabolic activation of PhIP in various human tissues.

Prevention of carcinogenesis by tea polyphenols

Tea, an extract of the leaves of the plant Camellia sinensis, has been considered a medicine and healthful beverage for ages. The beneficial effects of tea are thought to be due to its polyphenolic components. Herein, we discuss the present status of tea as a possible cancer chemopreventive agent, covering basic chemistry and biochemical activity of tea, pharmacokinetics of major tea components, studies in animal and cell lines, epidemiological investigations, and future challenges. Tea is one of the few chemopreventive agents known to have protective effects at different stages of the carcinogenic process. Tea constituents may inhibit this process by modulating signal transduction pathways leading to the inhibition of cell proliferation and transformation and enhancement of apoptosis. These activities may or may not be due to the antioxidative activity of tea polyphenols. The bioavailability and tissue levels of tea polyphenols is a key topic to be studied in order to understand the mechanisms of action of tea and its possible protection against cancer in humans.

Enhancement of dissolution of ethopropazine using solid dispersions prepared with phospholipid and/or polyethylene glycol

The purpose of this study was to improve the dissolution properties of a poorly water soluble and bioavailable drug, ethopropazine HCl (ET), by incorporating the drug in three different types of solid dispersion systems. Solid dispersions of ET were prepared using 1:1 (w/w) ratios of (1) phospholipid (1,2 dimyristoyl-sn-glycerophosphocholine) (DMPC), (2) polyethylene glycol 8000 (PEG8000), and (3) a novel combination of both DMPC and PEG8000. Using the solvent method of preparation, ET and DMPC and/or PEG were dissolved in chloroform, and solvent subsequently was evaporated using nitrogen gas. The resulting solid dispersion(s) was passed through a 60-mesh sieve. Characterization of ET/DMPC solid dispersion was performed by differential scanning calorimetry (DSC) and X-ray diffractometry studies. Dissolution studies conducted in phosphate buffered saline (PBS) (pH 7.4, 37 degrees C +/- 0.5 degrees C) using the USP type II (paddle) dissolution apparatus showed significant increases in the dissolution rate of ET with all the solid dispersions in this study. Specifically, within the first 5 min (D5), solid dispersions containing ET/DMPC (1:1) showed an eightfold increase in dissolution; in combination with DMPC and PEG8000 (1:1), there was an approximately sixfold increase; and a fourfold increase was observed with PEG8000 (1:1). Complete dissolution of all solid dispersions occurred within 60 min (D60) of the run. Storage of the ET/DMPC sample for over 4.5 months revealed a decrease in the dissolution rate when compared to freshly prepared sample. Overall, it was concluded that the dissolution rate of ET significantly improved when dispersed in all the selected carrier systems. However, the solid dispersion of ET/DMPC was observed to be superior to the other combinations used.

A study of factors controlling dissolution kinetics of zinc complexed protein suspensions in various ionic species

The presence of bound and unbound zinc in the crystal matrix of protein suspensions helps physically stabilize the crystal and limits the dissolution of the drug. In case of zinc insulin suspensions, dissolution can be promoted by complexation of zinc with an ionic species for which the zinc has a greater affinity, these complexing ions having either formulation and/or physiological relevance. The purpose of this work was to use ligand-complexed formulations of insulin suspensions to gain an understanding of these products' dissolution performance and to establish a fundamental understanding of the rate-limiting steps in zinc insulin dissolution. Our group has suggested that the critical factors to zinc insulin dissolution are: (1) chemical complexation (zinc with ionic species); and (2) drug transport (insulin diffusion and solubility). Dissolution studies conducted using different ionic species (acetate, phosphate, citrate and EDTA) in a spin-filter device demonstrated a rank order correlation for different sources of zinc insulin; it was observed that human zinc insulin dissolved faster than bovine insulin, these differences attributed to their binding properties and the respective affinities to the various ionic species used. Also, as the amount of crystallinity increased in a formulation, a rank order increase in dissolution times was observed. The project also identified a sensitive and reproducible dissolution testing methodology. Overall, this study demonstrated that: (1) the complexation rate-limiting step was more significant in the dissolution of zinc insulin than the diffusion rate-limiting step; and (2) that dissolution kinetics depended primarily on the source and solid state differences and the binding affinities of the zinc insulin.

Modification of radiation induced damage in mouse intestine by WR-2721

Intestinal protection in mice against radiation injury by WR-2721 (300 mg/kg body wt, i.p., 30 min before irradiation) was studied after whole body gamma irradiation (0.5, 1.5, 3.0, 4.5, or 6.0 Gy). Crypt survival and induction of apoptosis, and abnormal mitoses in crypt cells in the jejunum were studied on day 1, 3 and 7 after irradiation. Irradiation produced a significant decrease in crypt survival, whereas apoptosis and abnormal mitoses showed a significant increase from sham-treated control animals. Maximum changes in all the parameters were observed on day 1 after irradiation and the effect increased linearly with radiation dose. There was recovery at later intervals, which was inversely related to radiation dose. WR-2721 pre-treatment resulted in a significant increase in the number of surviving crypts, whereas the number of apoptotic cells in the crypts showed a significant decrease from respective irradiated controls on day 1 after exposure. The recovery was also faster in WR-2721 pre- treated animals. It is concluded that WR-2721 protects against gastrointestinal death by reducing radiation induced cell death, thereby maintaining a higher number of stem cells in the proliferating compartment.

An improved method for the determination of green and black tea polyphenols in biomatrices by high-performance liquid chromatography with coulometric array detection

Tea polyphenols are strong antioxidants and are believed to have beneficial health effects. However, the blood and tissue levels of these compounds are not well characterized because of a lack of suitable analytical methods for the biological resolution of these compounds. Previously, we developed methods for the analysis of three green tea catechins. Now we report an improved method for the measurement of the levels of the different catechins and theaflavins in biological fluids and tissues. The method includes digestion of the plasma, urine, or tissue samples with beta-d-glucuronidase and sulfatase, followed by extraction with ethyl acetate and subsequent separation by reversed-phase high-performance liquid chromatography (HPLC). The polyphenols are identified on the basis of their retention times, spectral analysis, and electrochemical behavior across an array of electrodes. In a single HPLC run, it is possible to determine the major catechins and theaflavins as well as some of the catechin metabolites. The detection limits for catechins and theaflavins are from 5 to 10 ng/ml of saliva, plasma, or urine.

Structural identification of two metabolites of catechins and their kinetics in human urine and blood after tea ingestion

Tea is a popular beverage consumed worldwide. The metabolic fate of its major constituents, catechins, however, is not well-known. In this study, two catechin metabolites were detected in the urine and plasma of human volunteers after ingestion of green tea. These metabolites were identified by LC/ESI-MS and NMR as (-)-5-(3',4', 5'-trihydroxyphenyl)-gamma-valerolactone (M4) and (-)-5-(3', 4'-dihydroxyphenyl)-gamma-valerolactone (M6). The renal excretion of M4 and M6 had a 3 h lag time and peaked 7.5-13.5 h after ingestion of a single dose of green tea, while (-)-epigallocatechin (EGC) and (-)-epicatechin peaked at 2 h. M4 and M6 were two major tea metabolites with urinary cumulative excretions as high as 8-25 times the levels of EGC and (-)-epicatechin in some of our subjects, and accounted for 6-39% of the amounts of ingested EGC and (-)-epicatechin. Both the metabolites appeared to be produced by intestinal microorganisms, with EGC and (-)-epicatechin as the precursors of M4 and M6, respectively. Repeated ingestion of green tea produced a slight accumulative effect of the metabolites. They were also detected in the plasma, exhibiting kinetics similar to those of the urinary metabolites, and in the feces. Study on these metabolites may help us further understand the cancer chemopreventive actions and other beneficial effects of tea.

Drug utilisation pattern in sexually transmitted diseases and its economic considerations--a prospective study

OBJECTIVES

WHO regularly revises guidelines for the treatment of these. There are very few studies reported on the drug utilization pattern of STD's in India.

METHODS

In the present study, 325 patients attending the STD clinic of Lok Nayak Hospital were analysed over a period of six months.

RESULTS

The demographic pattern of the patients was similar to those of studies reported earlier. Syphilis was the commonest of the STD's encountered; followed by viral STD's (c. acuminata and herpes progenitalis); gonorrhoea; chancroid and genital candidiasis. Out of a total of 409 drugs prescribed, the average number of drugs per prescription was 1.25. Sixty seven percent of the drugs were available in essential drug list of the hospital and 60% were prescribed in generic name. Ninety seven percent of the prescriptions were in accordance with WHO treatment guidelines. The cost of the drug treatment was comparable for c.acuminata, syphilis and chancroid while it was less for herpes progenitalis (HPG) due to acyclovir not being prescribed. However, it was more for gonorrhoea and candidiasis because of additional drugs.

CONCLUSIONS

The present study shows a trend towards rational prescribing. It would be interesting to compare the results with a non teaching hospital.

The FeLV-945 LTR confers a replicative advantage dependent on the presence of a tandem triplication

Feline leukemia virus (FeLV), like other naturally occurring retroviruses, is characterized by a high degree of genetic diversity. FeLV-945 is a natural isolate derived from non-B-cell non-T-cell lymphomas classified anatomically as multicentric. FeLV-945 exhibits a unique structural motif in the LTR composed of a 21-bp tandem triplication downstream of a single copy of enhancer. The unique FeLV-945 LTR is precisely conserved among eight independent multicentric lymphomas collected in a geographic cluster. Previous studies using reporter gene constructs predict that the FeLV-945 LTR would confer a replicative advantage on the virus that contains it, particularly in primitive hematopoietic cells. Such an advantage may account for the precise conservation of the unique LTR sequence. To test that prediction, a set of recombinant, infectious FeLVs was developed that are isogenic other than the presence of the FeLV-945 LTR or mutations of it. Replication assays show that the FeLV-945 LTR confers a distinct growth advantage in K-562, FEA, and 3201 cells and implicate the 21-bp triplication in that function. Replacement of two copies of the triplicated element with random sequence greatly diminished the replicative capacity, thus implicating the triplicated sequence itself in LTR function. The 21-bp triplication was shown to contain specific nuclear protein binding sites, which may account for the selective pressure to conserve the sequence.

A comparative study of anxiogenic effects of fluoroquinolones in rats

The present study compares the anxiogenic effects of three fluoroquinolones namely ciprofloxacin, ofloxacin and pefloxacin in rats using elevated plus-maze. The rats were treated with 12.5 mg/kg and 25 mg/kg of ciprofloxacin, ofloxacin or pefloxacin and then tested in elevated plus-maze half an hour later, for a period of 5 min. All the three fluoroquinolones decreased the time spent in open arm considerably. This decrease was statistically significant only with the higher doses of ciprofloxacin and ofloxacin (P < 0.05). Mean time spent in closed arm was increased by all the test drugs in both the doses. Increase was statistically significant with both the doses of ofloxacin (P < 0.05). Mean time spent in closed arm was increased by all the test drugs in both the doses. Increase was statistically significant with both the doses of ofloxacin (P < 0.05, P < 0.01 respectively) and higher doses of ciprofloxacin and pefloxacin (P < 0.01, P < 0.05 respectively). The number of entries in open arm and closed arm were decreased by both the doses of the three fluoroquinolones used in the study. The reduction in total number of arm entries by ciprofloxacin, ofloxacin and pefloxacin in both the doses was highly significant. The results suggest definite anxiogenic potential of fluoroquinolones.

Mucin histochemistry of esophagus in health and malignancy

AIMS

To study mucin histochemistry of the normal esophagus, esophageal adenocarcinoma, and carcinoma exhibiting glandular and squamous elements, to ascertain the origin of these tumors.

METHODS

Mucin histochemistry was studied in sections of the normal cardioesophageal junction obtained from 25 post-mortem specimens and in 12 mucin-secreting esophageal carcinomas.

RESULTS

The normal submucosal esophageal glands and three adenocarcinomas secreted predominantly sulfomucins; a mixture of neutral and sialomucins was seen in the nine carcinomas with squamous and glandular traits. Barrett's metaplasia was not encountered.

CONCLUSIONS

In the absence of Barrett's metaplasia, esophageal adenocarcinoma probably arises from the submucosal glands, whereas squamous carcinomas with mucin-secreting component could arise from metaplastic change in squamous epithelium, cardiac glands, or multipotent stem cells in the epithelium.

Regulation of the expression of cyclin-dependent kinase inhibitor p21 by E2A and Id proteins

The helix-loop-helix transcription factor E2A plays important roles not only in promoting cellular differentiation but also in suppressing cell growth. Id proteins, the inhibitors of E2A, have opposite effects on cell differentiation and growth. To understand the mechanisms by which E2A suppresses cell growth, we examined the role of E2A in regulating the expression of the cyclin-dependent kinase inhibitor p21CIP1/WAF1/SD11, which prevents cell cycle progression upon overexpression. By using transient-cotransfection assays of luciferase reporter constructs in HeLa cells, we have found that overexpression of E2A can transcriptionally activate the p21 gene. To identify the sequences that mediate this activation in the promoter of the p21 gene, we carried out mutational analyses. Out of the eight putative E2A-binding sequences (E1 to E8) in the promoter, the E1 to E3 sequences located close to the transcription start site are found to be essential. In addition, loss of the E boxes in the promoter also reduces p21 expression without cotransfection with E2A in HIT pancreatic cells, where the endogenous E2A-like activity is high. Furthermore, we have also shown that overexpression of E2A in 293T cells activates expression of the endogenous p21 gene at both the levels of mRNA and protein. In correlation with the finding that E47 overexpression leads to growth arrest in NIH 3T3 cells, we have shown that Id1 overexpression in NIH 3T3 cells accelerates cell growth and inhibits p21 expression. Taken together, these results provide insight into the mechanisms by which E2A and Id proteins control cell growth.

Cooperating events in lymphomagenesis mediated by feline leukemia virus

Feline leukemia virus (FeLV)-mediated lymphomagenesis in the domestic cat has been examined as a model of lymphoid malignancy in a naturally outbreeding population. The pathogenesis of two distinct, naturally occurring types of FeLV-induced tumors has been investigated: (1) a thymic lymphoma of T-cell origin, typical of FeLV-induced lymphoma, and (2) an extrathymic, extranodal lymphoma of non-B non-T-cell origin. The genetic features of these tumors are clearly distinguishable, and include determinants encoded both by the virus and the host. Virally encoded determinants of pathogenesis include the long terminal repeat (LTR) and the envelope SU protein. Cellular determinants include the involvement of a set of proto-oncogenes, and other factors characteristic of the specific cell type of origin of the tumor. Functional studies are aimed at evaluating the action and interaction of these genetic determinants in the pathogenesis of lymphoma in an animal model system.