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Biomedical subjects

I Johnson

Publications and source records attributed to I Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1991

The occurrence of Centrorhynchus (Acanthocephala) in shrews (Sorex araneus and Sorex minutus) in the United Kingdom.

Encysted acanthocephalans belonging to the genus Centrorhynchus were found in the body cavities of Sorex araneus (common shrew) and Sorex minutus (pygmy shrew) from Boxworth, Cambridgeshire, U.K. Fifty percent of the male S. araneus and 67% of the male S. minutus examined were found to be infected, with the mean intensity (+/-SD) being 54.3 +/- 91.3 and 14.7 +/- 18.4, respectively. The species of Centrorhynchus in the shrews may be Centrorhynchus aluconis, which is distributed widely in tawny owls, Strix aluco, in the United Kingdom. Shrews appear to serve as paratenic hosts for C. aluconis.

Acanthocephala↗
PubMed1988

Chemical synthesis, cloning and expression in mammalian cells of a gene coding for human tissue-type plasminogen activator.

A 1610-bp DNA duplex coding for human tissue-type plasminogen activator has been chemically synthesized using the phosphoramidite procedure, adapted for a custom-built gene synthesizer. The synthesizer, which was designed for both simplicity and speed, permits the rapid construction of relatively large genes and compares favorably in speed with alternative cDNA isolation procedures. The plasminogen activator gene has been expressed in mammalian cells and shown to produce authentic protein by an immuno-activity assay.

Base Sequence↗
PubMed1988

An evaluation of measles serodiagnosis during an outbreak in a vaccinated community.

During an epidemic of measles in a vaccinated community, five serodiagnostic tests were performed on 67 persons on whom clinical and epidemiological data were available. The test found most suitable for a rapid diagnosis of measles infection was an Enzyme Linked Immuno Sorbent Assay for the detection of specific IgM antibodies. Only one false negative IgM was recorded. In a group of 45 persons who fulfilled the clinical definition of measles, specific IgM antibodies were detected in the acute phase serum of only 30 (66.6%), of whom 17 were vaccinated. When the convalescent sera were tested, specific IgM antibodies were detected in 25 of the 28 (89.2%) vaccinated, and in 17 of the 17 (100%) non vaccinated clinical cases. A convalescent blood should be tested in persons with a rash illness and no IgM antibodies in the acute phase serum. There were individual variations in the time of appearance of IgM. On the day of onset of rash, IgM antibodies were detected in 7 of the 12 (58.3%). A history of prior vaccination is not always associated with immunity nor with the presence of specific antibodies.

Adolescent↗
PubMed1988

The value of immunoreactive lipase in acute pancreatitis.

We have evaluated a new agglutination test for serum immunoreactive lipase in 24 patients with abdominal pain and hyperamylasaemia. On admission all 20 patients with acute pancreatitis had a positive lipase test, 3 of the 4 patients who did not have pancreatitis had a negative lipase test. The sensitivity of the lipase test on day 1 is 100%, the specificity 96% and predictive value of a positive test is 95.2% compared to 83% for amylase. A negative test excludes pancreatitis. In addition, the test stays positive longer than hyperamylasaemia.

Acute Disease↗
PubMed1987

[14C]-triolein absorption: a useful test in the diagnosis of malabsorption.

The [14C]-triolein absorption test has been assessed using a preprepared fat meal in a procedure that can be completed within a working day on an inpatient or outpatient basis. An initial study showed complete discrimination between 30 control subjects and 13 patients with raised faecal fat excretion. A prospective evaluation in 57 patients under investigation for gastrointestinal disease showed a sensitivity of 85% and specificity of 93% (100% if two obese subjects are excluded). The test discriminates satisfactorily between patients with and without fat malabsorption and makes the measurement of faecal fat unnecessary in most circumstances.

Adult↗
PubMed1984

Intra-operative ultrasound.

Real time intraoperative ultrasound can provide instant evaluation of the operative field. One can expect high quality images of intracranial anatomy. With such information, the neurosurgeon can make determinations of direction and position as well as depth of the lesion. The procedure is safe and easy to perform. There are no radiation hazards present. It may be advantageous to keep the ultrasound available as one operates to visualize the progress of tumor removal; it can also be utilized after closure of the dura for bleeding or other complications. Biopsy procedures and localization of lesions in the brain can be extremely problematic. The neurosurgeon does not have the luxury of exploring a brain during a craniotomy as a general surgeon does in exploring an abdomen during laparotomy. Despite the fact that modern day technology with angiography and CT scanning may provide excellent preoperative localization information, the neurosurgeon must translate the information into his own perspective when operating and lesions may be missed by a millimeter. Once the transducer visualizes the brain substance, the neurosurgeon can actually observe the progress of the craniotomy.

Brain Injuries↗
PubMed1983

Menstrual dysfunction in cystic fibrosis.

Several factors potentially involved in the menstrual dysfunction of some females with cystic fibrosis were analyzed by a retrospective chart review. The mean age of menarche for the cystic fibrosis patients was 14.4 years, compared to 12.9 years for American females (p less than 0.001). At last evaluation, comparison of the mean figures for amenorrheic patients and for menarchal cystic fibrosis patients reveals statistically significant differences in the age of diagnosis, weight-height index, weight, height, percent of body fat, weight percentile, and height percentile. The highest correlative was weight (r = 0.59). Of our cystic fibrosis patients who were menarchal, 95% had a weight greater than 82 pounds, whereas 75% of those who were amenorrheic weighed less than 82 pounds. Menstrual irregularities, sexual activity, and contraceptive use among these patients also is discussed.

Adolescent↗
PubMed1980

Women physicians in a nonmetropolitan area.

The number and distribution of women physicians in a nonmetropolitan area of Illinois were identified from physician directories of 1950, 1965, 1972, and 1979; and comparisons were made with regional, state, and national data. Women physicians are less likely than men to enter nonmetropolitan practice. In the 53-county study area, 5 percent of the physicians are women, but almost three-fourths of the women are concentrated in six counties. Few women under 35 years of age are entering the 43 counties with populations under 50,000. Graduates of foreign medical schools, the majority with physician relatives also from foreign schools, constitute a sizable potion of the women physician pool in the smallest counties. The findings suggest the importance of finding ways of attracting women physicians to nonmetropolitan areas in need of such resources.

Adult↗
PubMed1978

Reinterpretation of the haematological effects of anticonvulsant treatment.

Blood-counts and folate assays were performed on samples from 102 adults at a residential institution for severe mental impairment. 96 of these patients were receiving anticonvulsant therapy and 6 were not. Only 1 subject had a macrocytic blood-picture, and 5 subjects had hypochromic anaemia. No features of incipient metaloblastic haemopoiesis were identified in the remaining samples. However, serum-folate measured by two assay methods was subnormal in 83% of the samples; red-cell folate was subnormal in 40%. It is concluded that the development of macrocytic anaemia in subjects on long-term anticonvulsants therapy is probably not related to the biochemical process which causes their low assayable folate but reflects inadequate nutrition.

Adult↗
PubMed1978

Measurement of serum folate by 75Se-selenofolate radioassay. Results of a multi-institutional clinical trial.

The authors report the multi-institutional evaluation of a radioassay for serum folate utilizing a gamma-labeled folate analog (75Se-pteroyl-L-methylselenocysteine). The assay is run as a one-step simultaneous addition at ambient temperature and is completed within 45 minutes. The assay data were reproducible within four study centers and correlated with both the Lactobacillus casei diagnostic groups and the clinical pictures.

Biological Assay↗
PubMed1978

Measurement of red cell folate with 75Se-selenofolate radioassay.

75Se-selenofolate radioassay was adapted for the purpose of red cell folate measurement. The results of assay of 124 whole blood samples by Lactobacillus casei microbiological assay and by radioassay using the adapted selenofolate method were concordant (r = 0.8). Red cell folate levels by the radioassay were below 170 microgram/1 in people who had haematological features of folate depletion. The distribution of results among reputedly healthy subjects extended down to 140 microgram/1.

Biological Assay↗
PubMed1977

Measurement of serum folate: experience with 75Se-selenofolate radioassay.

Three hundred and eighty-two serum samples were assayed for folate content by a standard Lactobacillus casei microbiological assay and by radioassay using the 75Se-selenofolate radioassay kit from the Radiochemical Centre, Amersham. Results showed encouraging concordance. Explanations were discovered for the few disparities. The radioassay procedure is simple and an assay batch can be completed in one working day.

Biological Assay↗