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Biomedical subjects

R Wong

Publications and source records attributed to R Wong.

At least 199 records · Page 11Linked to original sources
PubMed1982

Basic proline-rich proteins from human parotid saliva: complete covalent structure of protein IB-9 and partial structure of protein IB-6, members of a polymorphic pair.

The complete amino acid sequence of a basic proline-rich protein, IB-9, from human parotid saliva was determined by automated Edman degradation of peptides obtained by enzymatic cleavage of the intact protein with clostripain. The protein was digested with papain and elastase to obtain overlapping peptides. Automated Edman degradation of the intact protein was also performed. The protein consists of 61 amino acids, of which 26 are proline residues. The partial sequence of another human parotid basic proline-rich protein, IB-6, was also obtained. With one exception the first 54 residues of the two proteins are identical. An exceptional degree of internal reiteration occurs in both molecules, including several repeated sequences of 12-14 amino acids. The proteins show a high degree of homology with the C-terminal portion of the salivary acidic proline-rich protein C.

Amino Acid Sequence↗
PubMed1982

Evaluation of prefabricated lingual rest seats for removable partial dentures.

An investigation into the feasibility of using prefabricated lingual rest seats bonded to mandibular canines and incisors with an orthodontic enamel bonding system was undertaken. 1. A prefabricated lingual rest seat was designed and constructed to closely approximate the lingual contours of anterior teeth. 2. An in vitro study compared the mean failure loads of three orthodontic bonding systems. Two of the three have mean failure loads that are greater than twice the maximum occlusal-gingival forces that were applied to the abutments by removable partial dentures in the study by Maxfield et al. 3. A demonstration of the clinical feasibility of using these prefabricated lingual rests for support of removable partial dentures has been reported.

Dental Abutments↗
PubMed1981

Biliary excretion of glycolipid in induced or inherited glucosylceramide lipidosis.

Metabolically inert L-[1-14C]glucosylceramide is stored predominantly in the liver after intravenous administration to mice. The half-time of this glycolipid analogue in the liver is 3.5 days and its clearance occurs predominantly via the bile. Within the limited number of Gaucher specimens available for examination very high levels of glucosylceramide were found in the bile of one patient and in the liver of two patients with biliary obstruction. The question of a possible relationship between biliary excretion of glycolipid and the pathogenesis of Gaucher's disease will require further studies.

Animals↗
PubMed1981

Exercise duration to angina at two and twelve hours after timolol.

Eight patients who improved their exercise duration to angina or marked fatigue (greater than or equal to 25%) on timolol 10 to 30 mg twice daily over that on placebo 8 to 14 mo previously were subjects in a double-blind, randomized, crossover 4-wk study of the effect of timolol on exercise duration 2 and 12 hr after medication. One patient was discontinued from the study because unstable angina developed on placebo. Mean exercise duration on timolol over control was increased at 12 hr (p less than 0.02) and at 2 hr ( p less than 0.001) after drug. There was an increase in exercise duration greater than or equal to 25% on timolol over control compared with placebo in three of seven patients (43%) 12 hr after drug and in seven of seven (100%) 2 hr after drug. Timolol 10 to 30 mg twice daily prolongs exercise duration to angina or marked fatigue at 2 hr after drug and in some responders at 12 hr after drug.

Angina Pectoris↗
PubMed1981

Maintenance diet and the effects of furosemide on hamsters.

Experiment 1 indicated that furosemide, a diuretic, was ineffective in causing hamsters to excrete more urinary sodium when they were fed a sodium-replete diet. Neither the experimental nor the control animals showed any appreciable change in urinary sodium concentration when injected while maintained on Purina lab chow. However, experimental animals that were fed a sodium-deficient diet and then were injected with furosemide showed an increase in urinary volume as well as in sodium concentration in comparison with controls. Experiment 2 assessed the effect of furosemide on the hamsters' intake of saline when they were presented with either 0.9% NaCl and water or 2.0% NaCl solution and water. The results indicated that this diuretic increased the animals' intake of 0.9% saline but not of 2.0% NaCl. Ten days after this experiment, the same hamsters were then tested in a situation where they were presented with both 0.9% and 2.0% saline (Experiment 3). When these animals were injected with furosemide, both groups showed increased intake of 2.0% saline but not of 0.9% NaCl. These results indicate that the outcome of two-bottle preference tests is influenced by the combinations upon which the hamster is making the paired comparison. Experiment 4 involved the comparison of the single-stimulus and double-stimulus methods in assessing the effects of furosemide injections on the saline intake of different groups of hamsters. In general, the double-stimulus method appears to be more sensitive in detecting the natriorexigenic effects of furosemide.

Animals↗
PubMed1980

Effect of acebutolol and propranolol on premature ventricular complexes.

A double-blind, randomized study comparing the efficacy of intravenous acebutolol with propranolol on frequent premature ventricular complexes (PVCs) in 24 patients is reported. Frequent PVCs were abolished or reduced by 75% or more in 10 of 12 patients (83%) given acebutolol and in 10 of 12 patients (83%) given propranolol. The therapeutic effect of acebutolol lasted for at least 1 hr in 4 of 12 patients (33%), for at least 3.5 hr in 3 of 12 patients (25%), and for at least 4 hr in 2 of 12 patients (17%). The effect of propranolol lasted for at least 1 hr in 6 of 12 patients (50%), for at least 3.5 hr in 4 of 12 patients (33%), and for at least 4 hr in 4 of 12 patients (33%). Hence, intravenous acebutolol and propranolol were equally effective.

Acebutolol↗
PubMed1980

Reaction of systemic lupus erythematosus antinative DNA antibodies with native DNA fragments from 20 to 1,200 base pairs.

Double-stranded DNA fragments of varying sizes were isolated and tested for binding to systemic lupus erythematosus (SLE) antinative DNA antibodies. Fragments of 20-25, 40-50, 90-110, and 160-180 base pairs (bp), along with intermediate-size pieces were isolated by preparative gel electrophoresis of a limited micrococcal nuclease digest of calf thymus DNA. Larger helical polynucleotides of 160-200, 380, 600-1,000, and 1,200 bp were isolated by preparative gel electrophoresis of DNA from chicken erythrocyte nucleosomes and oligonucleosomes. The fragments behaved as base-paired structures as tested by thermal denaturation, resistance to S1 nuclease, and serological assays with antibodies to native or denatured DNA. At a concentration of 0.27 muM, fragments of 20-25 bp were able to react with two SLE sera in competition with native DNA. With these and two other sera, DNA of 40-50 bp was a much more effective competitor. One serum required DNA greater than 180 bp for competition in the concentration range tested. Denatured fragments were much less effective than native fragments. The results emphasize the heterogeneity of SLE antinative DNA antibodies, confirm that secondary structure of the antigen is important for specific binding to these antibodies, and support the suggestion that bivalent binding to one molecule may be important for high functional affinity.

Antibodies↗
PubMed1979

Verapamil in atrial fibrillation and atrial flutter.

A double-blind randomized study was performed to compare the efficacy of intravenous verapamil with saline in 28 patients with a rapid ventricular rate and atrial fibrillation or atrial flutter. Conversion of atrial fibrillation to sinus rhythm occurred in none of 14 patients after saline and in 3 of 20 patients (15%) 7 to 160 min after verapamil. The ventricular rate in atrial fibrillation was slowed greater than or equal to 15% in 2 of 14 patients (14%) by saline, in 17 of 20 patients (85%) by 1 dose of verapamil (p less than 0.001), and in 19 of 20 patients (95%) by 1 or 2 doses of verapamil (p less than 0.001). Conversion of atrial flutter to sinus rhythm occurred in none of 4 patients after saline and in 1 of 7 patients (14%) 105 min after verapamil. The ventricular rate in atrial flutter was slowed greater than or equal to 15% in none of 4 patients by saline, in 4 of 7 patients (57%) by 1 dose of verapamil, and in 7 of 7 patients (100%) by 1 or 2 doses of verapamil (p less than 0.001).

Adult↗
PubMed1979

Surgical management of the chronic venous ulcer: the Rob procedure.

Eighteen operations for venous ulceration were performed through a stocking seam incision with only one recurrence and minimal wound problems. The prolonged morbidity of venous ulcer disease can be alleviated with the method described. By a history and clinical examination followed by venography, a group of patients with venous ulcers can be identified who will benefit from an aggressive surgical approach.

Chronic Disease↗
PubMed1979

Respiratory abnormalities among grain elevator workers.

Twenty-two grain workers with respiratory symptoms and lung function abnormalities were studied. Our findings suggest that grain dust asthma probably has an allergic basis, even though skin tests and precipitin studies were negative using extracts of grain dust. Hypersensitivity pneumonitis and grain dust fever were not found in any of the subjects. We found that grain dust can cause airflow obstruction in two ways: first by inducing asthma, probably through immunologic mechanisms, and second, by causing industrial chronic bronchitis.

Adult↗