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Biomedical subjects

K Harrison

Publications and source records attributed to K Harrison.

At least 109 records · Page 6Linked to original sources

Multiple-sited (heterotopic) pregnancy after in vitro fertilization and gamete intrafallopian transfer.

Pregnancies occurring simultaneously in different body sites (heterotopic pregnancies) are a rare condition thought to occur in 1 of 30,000 spontaneous pregnancies. Individual cases may occur after in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT). In the past 4 1/2 years, our unit has performed 6,204 IVF/GIFT or pronuclear stage transfer cycles of treatment. Ten such pregnancies proven by surgical, ultrasound, and histological diagnosis have occurred. In the same period 640 IVF, 355 GIFT, and 6 pronuclear stage transfer clinical pregnancies were achieved. This suggests that the incidence of heterotopic pregnancy after assisted reproduction is closer to 1 of 100 pregnancies. Clinicians managing early complications of IVF, GIFT, and/or pronuclear stage transfer pregnancies should be aware of this relatively high incidence of concomitant intrauterine and extrauterine pregnancy.

Female↗

Purification and characterization of D-2-haloacid dehalogenase from Pseudomonas putida strain AJ1/23.

A D-2-haloacid dehalogenase was isolated and purified to homogeneity from Pseudomonas putida strain AJ1/23. The enzyme catalysed the stereospecific dehalogenation of the D-isomer of 2-chloropropionate. Using a new ion-chromatograph assay, the enzyme was found to catalyse the dehalogenation of short-chain 2-halocarboxylic acids. Maximum enzyme activity occurred at pH 9.5 and 50 degrees C and the enzyme was insensitive to most -SH reagents. The enzyme has an Mr of about 135,000 and appears to be composed of four subunits of identical Mr.

Hydrocarbons, Chlorinated↗

Screening for diabetes: does measurement of serum fructosamine help?

The diagnostic sensitivity and specificity for diabetes of serum fructosamine levels and fasting venous blood glucose concentrations were compared in 613 subjects during a diabetes community screening programme of 1049 adult Muslim Asians in Dar es Salaam, Tanzania. Using WHO (1985) criteria 228 had impaired glucose tolerance (IGT), 41 had previously been diagnosed as having diabetes while 32 had newly recognized diabetes. The mean (+/- SD) serum fructosamine levels were 20.9 +/- 3.2, 21.6 +/- 3.2, 23.9 +/- 4.9, and 30.1 +/- 7.9 (mumol g-1 albumin) in subjects with normal glucose tolerance, IGT, newly diagnosed diabetes, and previously diagnosed diabetes, respectively (p less than 0.001 for differences between groups). The specificity of values above the mean +2SD normal was 99% for abnormal glucose tolerance with a sensitivity of only 22% for diabetes. The predictive values were 44% and 97% for positive and negative results, respectively. Very little difference from normal was found for IGT subjects. Expressing fructosamine values in absolute terms or per gram albumin made little difference to sensitivity and specificity. The sensitivity was only 32% for fasting blood glucose greater than or equal to 6.7 mmol l-1, 73% for values greater than or equal to 5.5 mmol l-1, and 100% for fasting blood glucose greater than or equal to 4.5 mmol l-1. It is concluded that both serum fructosamine and fasting blood glucose are poor screening and diagnostic tests for diabetes and for IGT, and that glucose loading is required.

Adolescent↗

Distal intestinal obstruction syndrome in cystic fibrosis treated by oral intestinal lavage, and a case of recurrent obstruction despite normal pancreatic function.

An oral intestinal lavage solution has been successfully used in the treatment of six patients with chronic distal intestinal obstruction syndrome (previously referred to as meconium ileus equivalent) complicating cystic fibrosis and a further case of recurrent small bowel obstruction. The patient with recurrent obstruction is unusual in having no evidence of pancreatic maldigestion, which previously has been considered a prerequisite for the syndrome.

Acute Disease↗

Genetically-engineered microorganisms: I. Identification, classification, and strain history.

We have argued that accurate identification of the microorganism will form a cornerstone of the assessment of potential hazard. Appropriate methodology for identification exists, and is continually under development and refinement. Organizations such as the American Type Culture Collection will perform certified identifications for relatively low cost. Thus there appears to be little reason that an organism should not be identified insofar as current microbiology allows prior to submission for PMN review. We suggest that a complete microbiological characterization be considered an essential element of an acceptable PMN. To accomplish this, however, current institutional arrangements for the protection of trade secret information needed in the process of identification may need to be improved. An accurate identification of the strain will often provide access to important information with which to evaluate its ecology, pathogenicity, biochemistry, and genetics. Specialized texts, the scientific literature, and professional consultation are ready sources of such information. However, a major effort should be made to establish a data base that can specifically address the needs of biohazard evaluation. This could be done, in part, by collecting information about the construction, and about the behavior in the environment of genetically-engineered microorganisms that are now under development and will soon be tested or used. Identification information may also eventually be useful for the formulation of hypotheses about possible modes of harm or about relative safety, based on phylogenetic relationships. This is a very difficult undertaking at present, however. Microbial taxonomy is currently in a process of radical reevaluation as new macromolecular sequence information reveals previously unsuspected phylogenetic relationships, and disturbs categorizations based on older types of traits such as morphology, etc. This means that both inferences about relative safety and about possible modes of harm from taxonomic relationships must be highly tentative based on current information. Regulatory authorities may wish to consider requesting confirmatory DNA hybridization data or other macromolecular sequence comparisons in cases where strong arguments related to safety must be made from taxonomic information in relatively poorly studied groups of organisms. Detailed strain histories would provide valuable information for safety evaluations.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗

Influenza A/Philippines/2/82 outbreak in a nursing home: limitations of influenza vaccination in the aged.

The failure of the 1982-1983 influenza vaccine to protect elderly NHCU residents from clinical infection with influenza A/Philippines/2/82 resulted primarily from antigenic drift of the epidemic strain, inasmuch as the attack rates in the vaccinated and nonvaccinated patients were not significantly different. This experience supports the decision to replace A/Bangkok/1/79 with A/Philippines/2/82 virus antigen in the 1983-1984 influenza vaccine.

Adult↗

Multicentre comparative clinical evaluation of daily care solutions for rigid gas-permeable contact lenses.

Results of a multicentre, controlled, comparative study of two daily care regimens for rigid gas-permeable contact lenses are described. Whereas both regimens were generally effective and safe for the 69 patients wearing the Boston Lens, the Barnes-Hind regimen showed clinically and statistically significant advantages over the Boston Lens regimen: the proportions of patients in the Barnes-Hind group with corneal staining or palpebral conjunctival injection were reduced during the study and were lower on several occasions than the proportions of the Boston group.

Clinical Trials as Topic↗

Frey's syndrome.

Explore the source record for details and available documents.

Adult↗

Thallium-201 distribution in the thyroid: relationship to thyroidal trapping function.

Experiments were undertaken to determine the behavior of thallium-201 in the thyroid in relation to the iodide-trapping mechanism in rats. Iodide trapping was compared to thyroidal thallium-201 trapping 30 minutes after intravenous injection. Thallium-201 uptake followed iodide uptake in control rats. TSH- and T3-treated rats but did not decrease in the same manner as iodide concentration in perchlorate-treated rats. These studies suggest that thallium-201 distribution in the thyroid may reflect the cationic side of the iodide pump or possible thyroidal blood flow.

Animals↗

Biodistribution of intravenously injected [14C] doxorubicin and [14C] daunorubicin in mice: concise communication.

[14C] doxorubicin (adriamycin) and [14C] daunorubicin (daunomycin) are cardiotoxic antibodies used in cancer therapy. These drugs were examined as possible agents for the measurement of regional myocardial blood flow. The antibiotics were injected intravenously into mice, which were then killed after various intervals. At a chemical dosage of 0.5 mg per kilogram, the content of the heart never exceeded 0.60% of the administered dose for doxorubicin and 0.55% for daunorubicin. The cardiotoxic effect of these drugs, therefore, is probably related to a specific sensitivity of the heart, rather than to an avid uptake of the drugs by the cardiac muscle. Further studies seem warranted, using a lower chemical dosage and higher specific activity.

Animals↗

Thallium-201: non-invasive determination of the regional distribution of cardiac output.

Sapirstein (1) employed cationic radiopotassium to determine the fractional distribution of cardiac output to several organs. Thallium-201 can substitute for radiopotassium in myocardial imaging, and was evaluated in the present studies to determine the distribution of cardiac output in the anesthetized dog in comparison with tracer microspheres, both under control circumstances and following the infusion of norepinephrine in a dose sufficient to raise the blood pressure 20 mm Hg above control levels. The concentrations of thallium-201 and microspheres were similar in the heart, kidney, thyroid, and skeletal muscle in both control and norepinephrine-treated animals (r=0.93). Thallium concentration in the liver and lung exceeded that of microspheres, however, and probably is not related solely to the regional distribution of arterial perfusion. These data suggest that in the heart, kidney, thyroid, and skeletal muscle, thallium-201 distribution reflects the fractional distribution of cardiac output.

Animals↗