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Biomedical subjects

K Stewart

Publications and source records attributed to K Stewart.

At least 127 records · Page 7Linked to original sources
PubMed1987

Differential production of high molecular weight sulfated glycoproteins in normal colonic mucosa, primary colon carcinoma, and metastases.

Sulfated macromolecules synthesized in tumor and mucosa tissues derived from colorectal cancer patients were labeled with [35S]sulfate and separated into two fractions on DEAE-Sephacel: the slightly acidic peak (peak I) was eluted with 0.2 M NaCl and the highly acidic peak (peak II) was eluted with 0.5 M NaCl. A total of 40 specimens, which included primary colon cancer, liver metastases, and normal mucosa obtained at surgery (16 patients), were examined regarding the amount of peak I and peak II. The amount of peak I significantly decreased in the order of normal mucosa greater than primary tumors greater than metastases, while the amount of peak II did not significantly change among the tissues. Peak I was mostly resistant to chondroitinase ABC and nitrous acid treatment under acidic conditions, whereas combined chondroitinase-sensitive materials and nitrous acid-sensitive materials were greater than 80% of the radioactivity in peak II. The major radioactive component of peak I migrated at a position corresponding to Mr greater than 300,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and became Mr less than 40,000 after alkaline borohydride treatment. The major component of peak I was likely to be a sulfated glycoprotein containing sulfate groups on alkaline labile carbohydrate chains. Peak II consisted of a mixture of heparan sulfate proteoglycans and chondroitin sulfate proteoglycans. Differential incorporation of [35S]sulfate into peak I among normal mucosa, primary colon carcinoma, and colon carcinoma metastasis was observed. Therefore, decreased peak I production may be a biochemical change associated with colorectal cancer progression and metastasis.

Chromatography, Ion Exchange↗
PubMed1984

Treatment of valgus hindfoot in cerebral palsy by peroneus brevis lengthening.

Twenty cerebral-palsied patients (30 feet) with hindfoot valgus due to muscle imbalance were reviewed and it was shown that the deformity can be reduced by peroneus brevis lengthening. The method of choice is intramuscular lengthening, which reduces the power of peroneus brevis by one point on the MRC grading and corrects the hindfoot valgus by one grade of severity. For full correction by tendon lengthening, the deformity must be treated while it is still mild. Repeat lengthening may be necessary if there is a severe muscle imbalance.

Adolescent↗
PubMed1984

Foetal steroid sulphatase deficiency. A case report.

A normal healthy male infant was delivered by caesarian section because of low maternal urinary oestrogen excretion. Postnatal follow up showed that the child developed ichthyosis and that there was a family history of x-linked recessive ichthyosis. It is suggested that unexplained low urinary oestrogens should prompt enquiry about a family history of 'dry skin'.

Adult↗
PubMed1982

Normal in vivo eye dimensions by computed tomography.

In vivo measurements of the eye were obtained in 55 normal adults using computed tomography. Means and standard deviations were established for the maximum transverse and the maximum anteroposterior dimensions. Our data indicate that the widely used methods of Sweet and Pfeiffer-Comberg (for intraorbital foreign body localization) underestimate the actual in vivo dimensions of the eye.

Adult↗
PubMed1979

Species variation in dopamine receptor binding.

Binding of 3H-spiroperidol, 3H-apomorphine and 3H-ADTN (2-amino-6,7-dihydroxytetrahydronaphthalene) associated with dopamine receptors has been evaluated in corpus striatal membranes of calf, rat and human brains. Substantial species differences are apparent for numberous agonists and antagonists in competing for receptor binding. In general, dopamine receptor antagonists are more potent in rat and agonists more potent in calf. In competing for 3H-spiroperidol binding sulpiride, molindone and metaclopramide show the most pronounced species differences, being 3--10 times more potent in rat and human than in calf. In all three species agonists compete for 3H-spiroperidol binding with Hill coefficients less than one while antagonists inhibit 3H-spiroperidol binding with Hill coefficients of about 1.0. Conversely, 3H-apomorphine and 3H-ADTN binding in all three species is inhibited by antagonists with Hill coefficients less than 1.0 while agonists display Hill coefficients of about 1.0. In general agonists are more potent in competing for binding of 3H-apomorphine and 3H-ADTN than 3H-spiroperidol. However, a small component of dopamine, apomorphine and ADTN inhibition of 3H-spiroperidol binding displays very high affinity (IC50 about 1 nM). In human amygdala 3H-spiroperidol appears to label serotonin receptors predominantly.

Animals↗
PubMed1979

Acetaminophen overdose: a growing health care hazard.

Clinical reports support acetylcysteine as an effective agent in the prevention of severe hepatic necrosis and mortality in acetaminophen toxicity [2, 8, 13]. The agent is safe and easily administered to the patient. Further studies are needed before acetylcysteine is considered the agent of choice in the management of acetaminophen overdosage in this country.

Acetaminophen↗
PubMed1979

Narcolepsy: a family study.

We obtained medical and psychological assessments and 48-hr polysomnographic recordings on five sisters, three of whom had narcolepsy. Of the three, two were identical twins. All three narcoleptic sisters cited emotional stress and environmental demands for sustained performance as the major factors which aggravated their symptoms, and corresponding to this, the illness followed a different life course in each of the three. Most striking were the differences between the twin sisters in clinical symptoms and polysomnographic signs. One sister suffered from all the symptoms of narcolepsy and her sleep recording showed the typical sleep onset REM periods of the disease. Her twin suffered only from excessive daytime drowsiness and her sleep recording was normal--at least by the usual criteria. The sleep of all three narcoleptic sisters, however, was significantly more fragmented than that of their normal siblings. Our data suggested that excessive sleep fragmentation was a basic feature of narcolepsy and that it betrayed a constitutional predisposition for sleep to dissociate into its components and to become distributed around the nycthemeron. This process could be aggravated by emotional stress and by environmental demands for sustained vigilance, and this in turn, created the differences in symptoms and signs between individuals with identical genetic predispositions.

Aged↗