Sperm-mediated gene transfer into oocytes of the golden hamster: assessment of sperm function.

The possibility of sperm as a vehicle to deliver foreign DNA to oocytes was tested in hamsters. Epididymal spermatozoa, incubated with linearized plasmid DNA encoding ovine growth hormone (pCMXoGH), showed a spontaneous tendency to interact with DNA. Kinetics of sperm uptake of DNA was determined by using [32P]-labeled DNA. Spermatozoa took up the added DNA by 15-30 min and the uptake was inhibited by human seminal fluid in a dose dependent manner. Addition of DNA did not affect the functional competence of spermatozoa, in terms of their ability to undergo capacitation and acrosome reaction (34.5% +/- 2.2 vs 35% +/- 1.5). The fertilizing ability of DNA treated-spermatozoa from hamsters and humans was assessed by zona-free hamster egg penetration assay. Number of sperm penetrated per oocyte were 23 +/- 4.5 and 1.4 +/- 1.3 for hamster and human spermatozoa, respectively. Penetrated oocytes harbored sperm-treated DNA both with hamster (30.2 cpm/oocyte) and human (19.2 cpm/oocyte) spermatozoa. These results show that the hamster and human spermatozoa have a strong tendency to interact with exogenous (foreign) DNA and are able to transfer DNA to oocytes. Sperm may be used as a vector for DNA transfer and this approach has potential in the production of transgenic animals.

Calcium hydroxide as a root canal filling material in primary teeth--a pilot study.

A pilot study was carried out in five mandibular primary molars using calcium hydroxide (Ca(OH)2) Paste as root canal filling material to find out an alternative to the routinely used zinc oxide eugenol (ZnOE), which is non-resorbable and causes deflection of succedaneous teeth. The six month clinical and radiographic follow-up carried out at 2 months interval, revealed that the treated teeth with Ca(OH)2 as root canal filling material were successful, showing no pain and tenderness to percussion. A tendency for decrease in size of radiolucency was seen. Two teeth showed complete healing of the periradicular radiolucency. Depletion of Ca(OH)2 paste was seen from the root canals even prior to physiological resorption of roots in 2 out of 5 treated teeth.

Ultrasonic evaluation of portosystemic collateral circulation in portal hypertension.

The aim of the study was to evaluate portosystemic collateral circulation in relation to (1)individual etiological groups of portal hypertension., (2) Presence and size of esophageal varices, (3) esophageal sclerotherapy and (4) ascites. A prospective study of 101 patients of portal hypertension was carried out. Patients were divided into 4 etiological groups: Alcoholic cirrhosis (ALD) (38), Non-alcoholic cirrhosis (NALD) (35), non cirrhotic portal fibrosis (NCPF) (14) and extrahepatic portal vein obstruction (EHPVO) (14). Esophageal varices were assessed and graded endoscopically into 3 categories: no varix, small varices and large varices. Evaluation of portosystemic collateral circulation, other than esophageal varices was done ultrasonically. "Other" portosystemic collaterals (lienorenal, gastrorenal, dilated paraumbilical and umbilical veins, paraduodenal and gall bladdes varices) were seen in 26 out of 101 patients and more commonly in the non-cirrhotic groups (50%) [NCPF: 57.14%, EHPVO: 42.86%] than in the cirrhotic group (16.44%) [ALD: 13.5%, NALD: 20%]. Gall bladder varices were the only form of ectopic (extra esophagogastric) varices visualised with an overall incidence of 3.96%. Collateral shunts were seen more frequently in patients without varices (100%), than in patients with small varices (34.88%) or large varices (7.84%), and in patients having undergone esophageal sclerotherapy (57.14%). Collateral circulation did not contribute to the development of ascites. 37 patients with ascites did not have collateral shunts. We conclude portosystmic circulation plays a decompressive role in portal hypertension and prevents formation of esophageal varices or prevents them from increasing in size. It is seen more frequently in noncirrhotic patients and in those having undergone sclerotherapy and does not contribute to development of ascites.