Cavernosal dysfunction in a rabbit model of hyperhomocysteinaemia

OBJECTIVE: To investigate the effect of sustained hyperhomocysteinaemia (HHCy) on cavernosal smooth muscle function in a rabbit model of HHCy, developed using a methionine-enriched diet in which cavernosal responses were characterized, as elevated plasma levels of homocysteine may be a risk factor for vasculogenic erectile dysfunction. MATERIALS AND METHODS: Six New Zealand White rabbits were fed a diet supplemented with methionine (20 g/kg chow) for 4 weeks, while six control animals were fed a standard diet. Cavernosal strips were mounted in an organ bath and relaxation assessed when stimulated with carbachol, sodium nitroprusside (SNP), or noncholinergic, nonadrenergic (NANC)-mediated relaxation to electrical-field stimulation (EFS). Cavernosal tissue cGMP levels were assessed using an enzyme-linked immunosorbent assay, and superoxide (O(2) (.-)) production assessed using an assay of the superoxide dismutase (SOD)-inhibitable reduction of ferricytochrome c. RESULTS: The methionine-rich diet led to an early but sustained HHCy; cavernosal strips from animals after 4 weeks of HHCy had a significantly impaired relaxation response to carbachol, an index of endothelium-dependent nitric oxide (NO)-mediated relaxation. This impairment was reversed by incubating with either SOD or catalase. Relaxation with either SNP, an index of endothelium-independent NO-mediated relaxation, or NANC-mediated EFS-induced relaxation, was unaffected by HHCy. There was a corresponding significant reduction in cavernosal cGMP levels (index of NO activity) in the HHCy group, with a more than five-fold increase in cavernosal tissue O(2) (.-) production. CONCLUSION: Supplementing the diet of rabbits with methionine for 4 weeks caused an early and sustained HHCy and promoted a marked inhibitory effect on endothelium-dependent relaxation and NO formation in isolated corpus cavernosum, an effect mediated by reactive oxygen species.     

Potential risk of acute hepatotoxicity of kodo poisoning due to exposure to cyclopiazonic acid

Kodo millet (Paspalum scrobiculatum L.) is a staple food of some sections of people of North India. Consumption of Kodo millet is often found to cause intoxication and poisoning. The grains are frequently infested with Aspergillus tamarii Kita, which produced substantial amount of a mycotoxin, cyclopiazonic acid (CPA). Investigations were carried out to evaluate the hepatotoxic/preneoplastic changes in rat liver following single and multiple dose administration of CPA. Results showed a marked increase in the activity of glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) following CPA exposures, suggesting acute hepatotoxicity. Significant increase was also observed in gamma glutamyl transpeptidase (GGT) activity following CPA exposures, indicating preneoplastic changes in the liver. The results reveal that Kodo poisoning might cause acute hepatotoxicity in men and animals. The findings thus suggest that the consumption of contaminated Kodo millet is a serious health hazard due to exposure to CPA produced by Aspergillus tamarii associated with the millet.     

Cytochrome P-450 expression and lipid peroxidation in gallbladder cancer

BACKGROUND AND OBJECTIVES: Carcinoma of the gallbladder is the commonest neoplasm of the biliary tract; however, the etiology of this tumor remains unclear. METHODS: A case-control study was carried out comprising 50 patients with gallbladder cancer and 50 patients with cholelithiasis. Cytochrome P-450 estimation was carried out in the gallbladder tissue, and lipid peroxide product melonaldehyde (MDA) was measured in gallbladder bile. Statistical analysis was carried out by Student's t-test, and one-way analysis of variance (ANOVA). The Pearson correlation coefficient was calculated, and linear regression analysis was performed. RESULTS: The mean cytochrome P-450 concentration was significantly higher in patients with carcinoma of the gallbladder than in controls (t = 3.9, P < 0.001; F = 15.2, P = 0.002). Similarly, the mean concentration of melonaldehyde was significantly higher among cancer patients than in patients with gallstones (t = 2.7, P < 0.003; F = 7.37, P = 0.0078). No significant correlation was observed between tissue MDA and cytochrome P-450 levels (Pearson r = 0.1, P = 0.28). CONCLUSIONS: The results of the present study show that the rise in concentration of MDA is independent of the rise in concentration of cytochrome P-450; however, this is statistically insignificant. This could be due to biliary stasis leading to a rise in biliary concentration of melonaldeyde that is disproportionate to its production.     

Clinical and imaging anatomy of the scalp

The purpose of this paper is to illustrate the clinical and imaging anatomy of the scalp. The territories of the vessels, lymphatics, and nerves together with the epicranial muscles of the galea are illustrated. The traditional cross-sectional anatomic layers are described and their gross anatomic boundaries are given. They are regrouped into 3 coverings that can be distinguished on normal and pathologic magnetic resonance (MR) and computed tomography (CT) imaging. These are the epidermis/dermis, the subcutaneous layer, and the galea/subgalea/periosteum complex. This information will provide a handy reference to help describe scalp lesions.     

Metals in Horseshoe Crabs from Delaware Bay

We examined the concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the eggs, leg muscle, and apodeme (carapace musculature) in horseshoe crabs (Limulus polyphemus) from eight places on the New Jersey and Delaware sides of Delaware Bay to determine whether there were locational differences. Although there were locational differences, the differences were not great. Further, contaminant levels were generally low. The levels of contaminants found in horseshoe crabs were well below those known to cause adverse effects in the crabs themselves or in organisms that consume them or their eggs. Contaminant levels have generally declined in the eggs of horseshoe crabs from 1993 to 2001, suggesting that contaminants are not likely to be a problem for secondary consumers or a cause of their decline. Received: 25 January 2002/Accepted: 2 June 2002     

X-ray powder diffraction patterns for certain fluoroquinolone antibiotic drugs

X-ray powder diffraction (XRD) data for six pure fluoroquinolone antibiotic drugs, ciprofloxacin, norfloxacin, enrofloxacin, ofloxacin, pefloxacin and sparfloxacin have been obtained using a powder diffractometer. The drugs were scanned from a Bragg angle (2theta) of 10 degrees to 70 degrees. The obtained data were tabulated in terms of the lattice spacing (A) and relative line intensities (I/I(I)). This new information may be useful for the identification of these drugs.     

Haemangioma calcificans

Haemangioma calcificans is a relatively rare intracranial tumour, which is characterized by the presence of a calcified nodule in or near the brain. The patient is most often an adult of either sex, who develops seizures. The lesion can be large enough to produce raised intracranial pressure. The location of tumour is subcortical and often in the temporal lobe. It is usually solitary and benign in nature. Microscopically, there are thin-walled blood vessels separated by dense fibrous bands containing deposits of haemosiderin and calcium. On electron microscopy, tubular structures limited by a wall of electrodense material and irregular calcium deposits within them are prominent features. Four cases of haemangioma calcificans are described here with review of literature.