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Biomedical subjects

S Craig

Publications and source records attributed to S Craig.

At least 109 records · Page 6Linked to original sources

The effects of smoking on experimental skin flaps in hamsters.

To study the effects of the inhalation of cigarette smoke on the survival of skin flaps, 30 Syrian Golden hamsters were divided into three groups of 10. Two of these groups were acclimatized to cigarette smoke in increasing increments for 9 weeks in standard Hamburg I smoking cages. The third group of 10 (group A) served as controls and were sham-smoked throughout the experiment. After acclimatization, one group of 10 (group B) was smoked for a further 6 weeks. A standard axial-pattern flap was then raised on the dorsum of the animals. Ten animals in group C were smoked for 6 weeks preoperatively and for 2 weeks postoperatively, at which time the animals in all groups were sacrificed. All animals survived the experiment. The flaps in control group A all survived without necrosis. Two of the 10 dorsal flaps sustained terminal necrosis in group B animals. Six of the 10 flaps resulted in significant terminal necrosis in group C animals. Statistical analysis of the results indicated a significant comparison between control group A and group C of those animals smoked throughout the experiment. We conclude from this experiment that the inhalation of cigarette smoke consistent with that of a heavy smoker (2 packs per day) has an adverse effect on wound healing of skin flaps in hamsters. Apparently, cessation of smoking even at the time of surgical preparation of the flap obviates much of the noxious effect and increase flap survival significantly.

Animals↗

The smear test.

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Female↗

Elimination of toxicity from diets containing alfalfa seeds.

Cynomolgus macaques were fed autoclaved alfalfa seeds for up to 1 yr. There were no humoral signs of a syndrome resembling systemic lupus erythematosus. The data are in contrast to those previously reported in monkeys fed raw alfalfa seeds, in which a systemic lupus erythematosus-like syndrome was induced in a shorter interval. The autoclaved seeds retained antihypercholesterolaemic effects.

Anemia↗

LR white resin and improved on-grid immunogold detection of vicilin, a pea seed storage protein.

LR White resin combined with post-embedding immunogold labelling was used to localize the storage protein vicilin within developing pea seed cotyledons by electron microscopy. Fine structural preservation is comparable to that obtained with Spurr's resin, and antibody labelling is improved. More gold binds to protein bodies, to rough endoplasmic reticulum and to Golgi vesicles, and in addition, vicilin was detected within Golgi cisternae, a site not previously observed.

Acrylic Resins↗

Effects of phenytoin on man's immunity. Evaluation of changes in serum immunoglobulins, complement, and antinuclear antibody.

To determine the effects of phenytoin on serum immunoglobulins, complement, and antinuclear antibody conversion, a prospective, five-year longitudinal study was undertaken in 118 patients. Three major diagnostic groups were evaluated: 27 patients with idiopathic epilepsy, 50 with secondary epilepsy, and 41 with neuropathic syndromes without epilepsy. In addition, 83 normal volunteers were studied in a similar manner. Evaluations were performed prior to administration of phenytoin and at six-month intervals thereafter. Prior to treatment, patients with idiopathic epilepsy had a higher than expected incidence (13.5 percent, p less than 0.01) of low serum IgA (less than 61 mg/dl). Patients with secondary epilepsy and neuropathic disorders without epilepsy had a greater than expected incidence (9.2 percent, p less than 0.01; and 12 percent, p less than 0.01, respectively) of high serum IgA (greater than 417 mg/dl). Phenytoin treatment was associated with further decreases in serum IgA in patients with idiopathic epilepsy (p = 0.063) and secondary epilepsy (p = 0.008). Total serum IgE concentrations also decreased significantly in all patient categories during treatment with phenytoin. Minor decreases in serum IgG and IgM were noted, but serum IgD and complement remained unaffected. Antinuclear antibodies were observed with essentially the same frequency (10 percent) before and after phenytoin therapy.

Adolescent↗

Systemic lupus erythematosus-like syndrome in monkeys fed alfalfa sprouts: role of a nonprotein amino acid.

Hematologic and serologic abnormalities similar to those observed in human systemic lupus erythematosus (SLE) developed in cynomolgus macaques fed alfalfa sprouts. L-Canavanine sulfate, a constituent of alfalfa sprouts, was incorporated into the diet and reactivated the syndrome in monkeys in which an SLE-like syndrome had previously been induced by the ingestion of alfalfa seeds or sprouts.

Animals↗

The effectiveness of barrier methods of contraception with and without spermicide.

This paper reviews trials of the effectiveness of barrier contraception with and without spermicide, and discusses the advantages and disadvantages of using spermicides with barriers. There is very little evidence to allow comparison of the effectiveness of barriers with and without spermicide. Little or no evidence could be found to support many of the instructions given to users of barrier contraception. The lack of scientific data on this subject has prompted us to recommend research in specific areas. Until the findings of such research are available, the information which has emerged from this review suggests that the recommendations issued to users of barrier contraception should be brought up-to-date.

Contraceptive Devices, Female↗

The effect of early contact on maternal perception of infant behavior.

The effect of extra maternal-infant contact during the first postpartum hour on maternal perception of infant behavior one month after delivery was measured by the Broussard Neonatal Perception Inventories and the attachment questions of Klaus and colleagues. All mothers were indigent primiparas who vaginally delivered normal, term infants. 60 mother-infant dyads were randomly assigned to either an extra contact or routine contact group. 49 mothers were available 1 month later for home visits. Scores on the Neonatal Perception Inventories were not significantly affected by either degree of contact or the sex of the child. There was also no difference between contact groups in the maternal response to the attachment questions. Infant behaviors recorded by 24 mothers during the 4 days following home visits were similar in the 2 contact groups. Mothers reported significantly more negative behaviors for female than for male infants. Any effects of extra contact during the first hour after birth on maternal-infant interaction are unlikely to result from changes in maternal perception of infant behavior.

Adolescent↗

Role of the endoplasmic reticulum in the synthesis of reserve proteins and the kinetics of their transport to protein bodies in developing pea cotyledons.

Developing pea (Pisum sativum L.) cotyledons were labeled with radioactive amino acids, glucosamine, and mannose in pulse an pulse-chase experiments to study the synthesis, glycosylation, and transport of the reserve proteins vicilin and legumin to the protein bodies. Tissue extracts were fractionated on sucrose gradients to isolate either the endoplasmic reticulum (ER) or the protein bodies. Immunoaffinity gels were used to determine radioactivity in the reserve proteins (legumin and vicilin). After pulse-labeling for 45 min with amino acids, about half the total incorporated radioactivity coincided closely with the position of the ER marker enzyme NADH-cytochrome c reductase at a density of 1.13 g . cm-3 on the sucrose gradient. Both radioactivity and enzyme activity shifted to a density of 1.18 g . cm-3 in the presence of 3 mM MgCl2 indicating that the radioactive proteins were associated with the rough ER. Approximately half of the incorporated radioactivity associated with the rough ER was in newly synthesized reserve protein and this accounted for 80% of the reserve protein synthesized in 45 min. Trypsin digestion experiments indicated that these proteins were sequestered within the ER. In pulse-chase experiments, the reserve proteins in the ER became radioactive without appreciable lag and radioactivity chased out of the ER with a half-life of 90 min. Radioactive reserve proteins became associated with a protein body-rich fraction 20-30 min after their synthesis and sequestration by the ER. Pulse-chase experiments with radioactive glucosamine and mannose in the presence and absence of tunicamycin indicated that glycosylation of vicilin occurs in the ER. However, glycosylation is not a prerequisite for transport of vicilin from ER to protein bodies. Examination of the reserve protein polypeptides by SDS PAGE followed by fluorography showed that isolated ER contained legumin precursors (Mr 60,000-65,000) but not the polypeptides present in mature legumin (Mr 40,000 and 19,000) as well as the higher molecular weight polypeptides of vicilin (Mr 75,000, 70,000, 50,000, and 49,000). The smaller polypeptides of vicilin present in vicilin extracted from protein bodies (Mr 12,000-34,000) were absent from the ER. The results show that newly synthesized reserve proteins are preferentially and transiently sequestered within the ER before they move to the protein bodies, and that the ER is the site of storage protein glycosylation.

Biological Transport↗

Post-embedding immunolabelling. Some effects of tissue preparation on the antigenicity of plant proteins.

The sensitivity of detection of proteins by immunolabelling embedded and sectioned material depends upon retention of antigenicity during tissue processing. Losses in pea seed storage protein antigenicity have been assessed using a solid phase radioimmunoassay. Storage proteins adsorbed to wells of microtiter plates were treated with the various "tissue preparation" steps and reacted with 125I-antibodies to the storage proteins. The glutaraldehyde or formaldehyde fixation steps caused approximately 60% and 30% loss in antigenicity, respectively. With each subsequent preparative step, losses accumulate and following treatment with Spurr's epoxy resin reached approximately 85% and 90%, respectively. However, if Lowicryl K4M, a methacrylate-acrylate embedding medium was used, losses were retained at approximately 70% and 60%, respectively. These observations have been verified on sections of embedded material using two labelling procedures, with protein A-gold and ferritin as the markers.

Cytological Techniques↗

Allergic bronchopulmonary aspergillosis and bilateral fungal balls terminating in disseminated aspergillosis.

A unique case of allergic bronchopulmonary aspergillosis associated with bilateral apical aspergillomas terminating in disseminated aspergillosis is presented. Postulated mechanisms of this combination are discussed with respect to the patient's clinical findings. The contribution of systemic and aerosolized corticosteroids are considered major contributing factors to dissemination of disease.

Adult↗

Immunofluorescent localization of pea storage proteins in glycol methacrylate embedded tissue.

Improved immunofluorescent techniques have been developed for the high resolution light microscopic localization of intracellular antigens in plant tissue. Thin sections of pea cotyledon tissue which had been fixed in paraformaldehyde and embedded in glycol methacrylate were reacted with mono-specific antibodies to the storage proteins legumin and vicilin. These antibodies were raised in sheep, purified by affinity chromatography and tested by immunoelectrophoresis and immunodiffusion. Using the indirect technique, rhodamine-labeled antibodies permitted specific fluorescent localization of the legumin and vicilin to small (ca. 1 micrometer) cytoplasmic organelles in near mature tissue. Subsequent histochemical staining verified the proteinaceous nature of these organelles. Parameters affecting staining specificity and background fluorescence are discussed.

Fluorescent Antibody Technique↗

Treatment of ragweed hay fever with intranasally administered disodium cromoglycate.

In a double-blind study the therapeutic effect of a 4% disodium cromoglycate (DSCG) nasal solution was evaluated in thirty-nine patients with acute symptoms of ragweed hay fever. Patients were randomly assigned to the DSCG or placebo group as they presented with allergic rhinitis. Overall, the DSCG was not more effective than placebo in controlling the symptoms of rhinitis or in decreasing the need for concomitant antihistamines or corticosteroids. Among patients with the highest pretreatment serum ragweed-specific IgE (RW IgE) levels, drug-treated patients had some reduction in symptoms as compared to their placebo controls during the peak of the ragweed pollen season. DSCG treatment did not influence the usual seasonal rise in RW IgE. Side effects from both the active and placebo aerosols were frequent but mild. We conclude that DSCG nasal solution used for the treatment of seasonal ragweed allergic rhinitis is relatively ineffective.

Administration, Intranasal↗

Structure and function of cholera toxin and hormone receptors.

The enterotoxin from Vibrio cholerae is a protein of 100,000 mol wt which stimulates adenylate cyclase activity ubiquitously. The binding of biologically active 125I-labeled choleragen to cell membranes is of extraordinary affinity and specificity. The binding may be restricted to membrane-bound ganglioside GM1. This ganglioside can be inserted into membranes from exogenous sources, and the increased toxin binding in such cells can be reflected by an increased sensitivity to the biological effects of the toxin. Features of the toxin-activated adenylate cyclase, including conversion of the enzyne to a GTP-sensitive state, and the increased sensitivity of activation by hormones, suggest analogies between the basic mechanism of action of choleragen and the events following binding of hormones to their receptors. The action of the toxin is probably not mediated through intermediary cytoplasmic events, suggesting that its effects are entirely due to processes involving the plasma membrane. The kinetics of activation of adenylate cyclase in erythrocytes from various species as well as in rat adipocytes suggest a direct interaction between toxin and the cyclase enzyme which is difficult to reconcile with catalytic mechanisms of adenylate cyclase activation. Direct evidence for this can be obtained from the comigration of toxin radioactivity with adenylate cyclase activity when toxin-activated membranes are dissolved in detergents and chromatographed on gel filtration columns. Agarose derivatives containing the "active" subunit of the toxin can specifically absorb adenylate cyclase activity, and specific antibodies against the choleragen can be used for selective immunoprecipitation of adenylate cyclase activity from detergent-solubilized preparations of activated membranes. It is proposed that toxin action involves the initial formation of an inactive toxin-ganglioside complex which subsequently migrates and is somehow transformed into an active species which involves relocation within the two-dimensional structure of the membrane with direct perturbation of adenylate cyclase molecules (virtually irreversibly). These studies suggest new insights into the normal mechanisms by which hormone receptors modify membrane functions.

Adenylyl Cyclases↗