Haematological aspects of antenatal diagnosis for thalassaemia in Britain

The results are described of 200 antenatal diagnostic tests for haemoglobinopathies performed on samples of fetal blood obtained during the second trimester of pregnancy. Haemoglobin A synthesis in the fetus was measured by incorporation of tritiated leucine in vitro and separation of the globin chains on CM23 columns. The range of HbA synthesis detected was 3.5-8.0% in normal fetuses, 2.0-5.0% in fetuses with thalassaemia trait, and less than 1.6% in fetuses with thalassaemia major. There were eight cases in which other haemoglobinopathies were diagnosed. 29% of the pregnancies were terminated because thalassaemia major was diagnosed, and 9.5% of the remaining healthy fetuses were lost for obstetric reasons. Follow up has been possible for 96% of the 124 surviving babies and three misdiagnoses have come to light; one false positive (0.5%) and two false negatives (1%). These figures represent a first effort at antenatal diagnosis for haemoglobinopathies and it is likely that they will improve with the passage of time.     

Effect of a specific platelet-activating factor antagonist on cardiovascular and peripheral cellular responses to colonic ischemia and reperfusion in anesthetized ponies

The role of platelet-activating factor in mediating the cardiovascular and peripheral cellular responses to large-colon ischemia and reperfusion, was explored in anesthetized ponies. A specific platelet-activating factor (PAF) antagonist (WEB 2086) was administered to a group of 6 ponies, and another 6 ponies (controls) were given an equivalent volume of saline solution, prior to 1 hour of large-colon torsion. After correction of the torsion, ponies were monitored during the reperfusion period. Significant (P < 0.05) hypotension and metabolic acidosis developed in all ponies after correction of colonic torsion, cardiac index increased initially, but then decreased significantly (P < 0.05) over the study period. Mean times between correction of torsion and onset of cardiac failure and death were not different between groups. Significant (P < 0.05) thrombocytopenia developed during the reperfusion period in control ponies, but not in WEB-treated ponies. Blood leukocyte concentration in control ponies was more variable and significantly (P < 0.05) decreased immediately upon reperfusion, compared with that in WEB-treated ponies. We conclude that although the cardiovascular responses to colonic ischemia and reperfusion are not prevented by use of a specific PAF-antagonist, specific peripheral cellular responses are mediated by PAF.     

Evaluation of high-resolution CT and MR cisternography in the diagnosis of cerebrospinal fluid fistula

BACKGROUND & AIMS: Whether inflammation of the cardia indicates gastroesophageal reflux disease (GERD) and/or is a manifestation of pangastritis caused by Helicobacter pylori infection is unknown. The aim of this study was to evaluate the relationship between cardia inflammation, H. pylori infection, and cardia intestinal metaplasia in patients with and without GERD. METHODS: Patients with GERD were compared with controls undergoing endoscopy for a variety of other conditions. Endoscopic biopsy specimens from the distal esophagus and cardia, fundus, and antrum were evaluated for inflammation, H. pylori infection, and intestinal metaplasia. RESULTS: Neither the prevalence of H. pylori infection (controls, 48%; GERD, 41%) nor cardia inflammation (controls, 41%; GERD, 40%) differed between groups. All 11 controls and 22 of 23 patients with GERD (96%) and cardia inflammation had H. pylori infection. Esophagitis was more common among GERD patients (33%) than controls (7%; P = 0.01). Cardia intestinal metaplasia was more common among controls (22%) than GERD patients (3%; P = 0.01); all had cardia inflammation, 7 had H. pylori infection, and 6 had metaplasia elsewhere in the stomach. CONCLUSIONS: The prevalence of cardia inflammation is similar in patients with and without GERD and is associated with H. pylori infection (P < 0.001). Cardia intestinal metaplasia is associated with H. pylori-related cardia inflammation (P = 0.01) and intestinal metaplasia elsewhere in the stomach, indicating that it is distinct from Barrett's esophagus.     

Ferrireductase from Pichia guilliermondii: properties and regulation of activity and synthesis

Iranian Jews represent an ancient community with a very high degree of inbreeding. Although the community remained relatively isolated, it had strong ties with Babylonian Jewry in Iraq. Several genetic disorders have been reported to be frequent among Iranian Jews, in particular, corticosterone methyloxydase deficiency type II, polyglandular syndrome, and rimmed vacuole myopathy. Based on the data collected in our clinic, recessive and dominant deafness also appear to be frequent. Other diseases, such as beta-thalassemia, achromatopsia, colobomatous microphthalmia, Dubin-Johnson syndrome, and congenital myasthenia gravis, were frequent in both the Iranian and Iraqi Jewish communities. The place of origin of the families within Iran and the results of molecular studies suggest some reason(s) for the high frequency of these disorders among Iranian Jews. While the high frequency of some of the disorders, such as corticosterone methyloxydase deficiency type II, represents a founder effect, in other diseases (such as beta-thalassemia) it was secondary to heterozygote advantage.     

A microbiological validation and criteria for the efficacy of the use of CO2 and YAG lasers in the surgical treatment of cholecystitis

A considerable frequency of infected bed of the gallbladder in different forms of cholecystitis was established, the anaerobic microflora being inoculated more often. A direct dependence of the frequency of infecting the bile and gallbladder bed on the patient's age and duration of having chronic cholecystitis was shown. The sterilization and prevention of reinfection of the gallbladder bed after the removal of it can be achieved by the laser irradiation of the total bed surface inspite of the absence of clear symptoms of acute inflammation of the bladder and the surrounding tissues, and the cleansing should be performed after the manipulations on extrahepatic bile ducts are completed.     

Characterization of a beta-lactamase from Mycobacterium smegmatis SN2

Beta-lactamases have been reported to be largely responsible for beta-lactam resistance in Mycobacteria. We report the characterization of a cell-associated beta-lactamase from Mycobacterium smegmatis. The enzyme hydrolyzed the "beta-lactamase-stable" oximinocephalosporins. Nitrocefin was the best substrate. 6-Beta-iodopenicillanate, clavulanate and sulbactam were effective inhibitors, whereas the Ki value for aztreonam was high. From its substrate and inhibitor profile, the enzyme appeared to be a cephalosporinase of group 2e.     

Construction of a homodimeric dihydrofolate reductase-thymidylate synthase bifunctional enzyme

A gene encoding a bifunctional homodimeric dihydrofolate reductase- thymidylate synthase (DHFR-TS) was constructed by destroying the stop codon of Escherichia coli dihydrofolate reductase (DHFR) and joining the coding sequences of the monofunctional enzymes by a five amino acid linker. The protein was designed to mimic features of active site proximity and electrostatics in the protozoan DHFR-TSs which are believed to be important in channeling of the DHFR substrate, H2folate, to TS. The genetically engineered catalytically active homodimeric bifunctional DHFR-TS was expressed, purified and characterized. The component activities of the purified bifunctional enzyme had kinetic properties similar to those of the monofunctional TS and DHFR, but unlike the authentic bifunctional enzymes from protozoa this enzyme did not kinetically channel dihydrofolate from DHFR to TS.