Detection of mutations in the p53 gene in human head and neck carcinomas by single strand conformation polymorphism analysis.

Using the polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis, we have examined the highly conserved regions of the p53 gene in 58 biopsy samples of head and neck tumors. Mutations were found in 13/58 (23%) tumor specimens, but not in 6 normal tissues. Ten of 13 mutations were due to single base changes and the remaining 3 were 1- or 8-base deletion mutants. These mutations were clustered in exons 5 and 7 and resulted in amino acid changes. Our results seem to indicate that mutations in the p53 gene contribute to a significant number of cases of the head and neck tumors including 20% of nasopharyngeal carcinoma biopsies. The relationship of Epstein-Barr virus or human papillomavirus and p53 gene mutations in this group of cancers was also analyzed and discussed.     

Occurrence of tetrodotoxin and paralytic shellfish poison in the Taiwanese crab Lophozozymus pictor

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in all 15 specimens of the xanthid crab Lophozozymus pictor collected from northern Taiwan in 1993. The average toxicity of crab specimens was 921 ± 231 (mean ± S.E.) mouse units. The toxin of crab was partially purified and then identified. It was found that the crab toxin contained TTX and gonyautoxin. The ratio of TTX to gonyautoxin for crab toxin was about 9:1.     

Adsorption of Salmon Calcitonin to PLGA Microspheres

Purpose. The interaction of salmon calcitonin (sCT) and poly (d,l-lactide-co-glycolide) was detected during preparation and evaluation of microspheres. The purpose of this study was to quantitate the extent and nature of the interaction. Methods. Blank microspheres were prepared by an aqueous emulsification solvent extraction technique. Adsorption studies were carried out at six concentrations of sCT and three concentrations of microspheres. Adsorption isotherms were constructed using the Langmuir and Freundlich treatments. Results. Adsorption at 1 mg/ml sCT concentration resulted in almost complete depletion of the peptide from the adsorption medium with the time to reach maximum adsorption decreasing with increasing microsphere concentration. At sCT concentrations below 100 µg/ml, a true equilibrium occurred in 1 hour or less while at higher concentrations (up to 350 µg/ml), a transient equilibrium was reached in 1 to 2 hours, followed by further adsorption of the peptide. The adsorption followed the Langmuir isotherm at concentrations below 200 µg/ml, indicating formation of a monolayer. Multilayer interaction, described by the Freundlich isotherm, occurred at higher concentrations and resulted in complete depletion of sCT from the adsorption medium. The affinity constant during monolayer formation was 0.09 and the plateau surface concentration was 5.1 µg/mg. The multilayer peptide-peptide adsorption showed a lower affinity (0.025) but higher capacity (24 µg/mg) than the monolayer peptide-polymer adsorption. Conclusions. The results show that poly (d,l-lactide-co-glycolide) microspheres have a high adsorption capacity for sCT which must be considered in formulating a controlled delivery product of this peptide.     

The role of ostiomeatal complex obstruction in maxillary fungus ball.

OBJECTIVE: The aim of this study was to clarify the role of ostiomeatal complex obstruction in maxillary fungus ball. STUDY DESIGN AND SETTING: Comparative study in a hospital setting of the mean Lund-Mackay scores for the anterior ethmoid and frontal sinuses of 54 versus 48 patients with maxillary fungus ball versus chronic unilateral rhinosinusitis, respectively. RESULTS: In cases with partial opacification in the maxillary sinus, the anterior ethmoid and frontal sinuses were diseased in the chronic unilateral rhinosinusitis group but not in the maxillary fungus ball group. In cases with total opacification in the maxillary sinuses, all anterior ethmoid and frontal sinuses in both groups were diseased, but the disease condition of the frontal sinuses was significantly less severe in the maxillary fungus ball group (P < 0.001). CONCLUSION AND SIGNIFICANCE: In this era of evidence-based medicine, we provide statistical data supporting the principle that maxillary fungus ball is not associated with osteomeatal complex obstruction and that another as-yet-unexplained mechanism must be responsible. EBM rating: B-3b.     

Prevalence of depressive and anxiety disorders in an assisted reproductive technique clinic

Hum. Reprod., 19, 2313–2318, 2004 The following mistake     

L-ascorbic acid produces hypoglycaemia and hyperinsulinaemia in anaesthetized rats

L-Ascorbic acid (Vitamin C) produced a marked reduction in the blood glucose concentration following intravenous injection (20-100 mg kg-1) to anaesthetized rats. This hypoglycaemic effect was accompanied by an increase in plasma insulin concentration. D-ascorbic acid produced a similar hypoglycaemic effect.