Search PubMed⌕ Search

Biomedical subjects

L K Smith

Publications and source records attributed to L K Smith.

At least 73 records · Page 4Linked to original sources

Management of hypercholesterolemia: evaluation of practical clinical approaches in healthy young adults.

A work site-located clinic screened 6,000 employees (91 percent participation) and identified 146 hypercholesterolemic subjects (100 percent initial participation, 12 percent subsequent dropout rate). The subjects, aged 20 to 50 years, were randomly classified into four groups: Group A, treatment in a lipid intervention clinic with diet for 6 weeks, then diet plus clofibrate for the subsequent 18 weeks; Group B, diet treatment from a clinic nutritionist with the cooperation of the subject's private physician; Group C, referral for treatment by a private physician; and Group D, no intervention. Initial mean cholesterol was 294 mg/100 ml. At 24 weeks, all intervention groups had decreases in serum cholesterol (Group A, 12 percent; Group B, 15 percent; Group C, 17 percent; P less than 0.001). The control group (D) had a small decrease in cholesterol (4 percent). Decreases in cholesterol were correlated with weight loss and decrease in fasting serum triglycerides but not with the use of clofibrate. Serum cholesterol can be reduced in healthy young adults by several practical methods.

Adult↗

Synthesis of 5,6-dihydro-8(7H)-quinolinone thiosemicarbazones as potential antitumor agents.

5,6-Dihydro-8(7H)-quinolinone was synthesized and converted into thiosemicarbazones which could be considered to be semirigid analogues of the 2-formylpyridine thiosemicarbazone class of antitumor agents. The Z and E isomers were separated and identified by 1H NMR and UV. Although the compounds showed essentially no inhibitory activity against the enzyme alkaline phosphatase, several of these agents had demonstrable anticancer activity in mice bearing the P388 leukemia. The E-configuration analogues in general were slightly more active than their corresponding Z isomers.

Alkaline Phosphatase↗

Phosphorus-nitrogen compounds. 20. Thiophosphorus hydrazones.

Six pyridine-2-carboxaldehyde, one pyridine N-oxide 2-carboxaldehyde, and five diketone thiophosphoric hydrazones, three thiophosphoric hydrazides, and two cupric chelates were synthesized. The chelates and nine of the hydrazones were tested against Ehrlich ascites carcinoma. Seven of these latter agents were administered concurrently with either cupric and/or ferrous salts to mice bearing this tumor. The greatest activity was found with the chelate, cimethyl pyridine-2-carboxyaldehyde phosphorothioic hydrazone-copper (1:1). The hydrazone portion of this chelate also formed a ligand-copper (2:1) complex. Although all of the hydrazones but one were inactive when evaluated alone, the concurrent injection of cupric ion increased survival times by an avoli alkaline phosphatase was found to be inhibited by two thiosemicarbazones in a manner similar to that previously reported by these agents against alkaline phosphatase derived from Sarcoma 180-6-thiopurine resistant ascites cells. None of the 14 hydrazides or hydrazones tested against E. coli enzyme displayed significant inhibition.

Alkaline Phosphatase↗

Management of type IV hyperlipoproteinemia. Evaluation of practical clinical approaches.

A lipid intervention clinic screened 4000 employees (89% participation) and identified 150 type IV subjects (top 5 percentile triglyceride values, 100% initial participation, 6% drop out). The 150 healthy type IV subjects, ages 20 to 49, were randomly divided into treatment subgroups: A, treatment by clinic nutritionist and physician with the National Heart and Lung Institute's type IV diet for 6 weeks, then diet plus clofibrate for 18 weeks; B, same treatment by private physician; C, no intervention for 24 weeks, subjects advised of abnormality. The group A mean fasting serum triglyceride of 407 mg/dl declined 50% at 6 weeks, 61% at 12 weeks, and was unchanged at 24 weeks (P less than 0.0005 at 6, 12, 24 weeks). Group B triglyceride decreased 42%, 50%, 41% (P less than 0.0005 at 6, 12, 24 weeks). Group C triglyceride declined 20%, 1st to 24th week. Body weight decreased 8% (A) and 4% (B) at 6 weeks (P less than 0.0005) and was unchanged at 24 weeks. The maximum cholesterol decrease (A) was 11% (P less than 0.0005). Type IV hyperlipoproteinemia can readily be identified in a working population; treatment by clinic or private physician will markedly lower fasting serum triglyceride values in apparently healthy type IV subjects for at least 24 weeks.

Adult↗

Motor innervation of the flexor pollicis brevis: an electromyographic study.

Percutaneous stimulation of the ulnar and median nerves at the wrist, with simultaneous recording of action potentials on a standard electromyograph oscilloscope, was performed to observe the motor innervation of the flexor pollicis brevis muscle. Both the deep and the superficial heads of the muscle were studied in twenty-three subjects. Results showed that the most common pattern of innervation was exclusive ulnar nerve supply in both heads, with 52.4 percent of the subjects showing this pattern. Dual supply by both median and ulnar nerves occurred next in frequency with 19.0 percent showing this pattern in both heads of the muscle. Exclusive median nerve supply was observed in only 9.5 percent of the total cases studied. The remaining 19 percent showed varying patterns, with each head of the muscle supplied differently. If no differentiation between deep and superficial heads is made, this 19 percent may be considered as dual innervation of the muscle. In this case, it may be concluded that 38 percent of the muscles studied showed some type of dual innervation.

Adult↗

Atrioventricular conduction in patients with clinical indications for transvenous cardiac pacing.

Eighty patients with clinical indications for cardiac pacing had atrioventricular conduction analysed by His bundle study. The indications for cardiac pacing included high grade atrioventricular block, sick sinus node syndrome without tachycardia, bradycardia-tachycardia syndrome, unstable bilateral bundle-branch block, and uncontrolled ventricular irritability. Complete heart block, Wenckeback block (Mobitz I), and 2:1 block were noted proximal and distal to the His bundle. Mobitz II block only occurred distal to the His bundle. Of special interest were the high incidence of distal conduction abnormalities by His bundle analysis (40/80, 50%), the re-establishment of normal atrioventricular conduction in acutely ill patients with recent evidence of heart block, and the high incidence of intraventricular conduction disturbances on standard electrocardiogram (48/80, 60%).

Aged↗

Stair climbing elicits a lower cardiovascular demand than walking in claudication patients.

PURPOSE: Peripheral arterial disease patients limited by claudication pain frequently have concomitant-cardiovascular problems during exercise, such as hypertension and myocardial ischemia. Thus, for testing and rehabilitation purposes, exercise which elicits lower heart rate and blood pressure at a given metabolic intensity would be preferred over a more demanding task. The purpose of this study was to compare the cardiovascular responses of claudication patients during walking and stair climbing at a similar level of oxygen uptake. METHODS: Ten patients limited by claudication pain performed treadmill walking and stair climbing tests. RESULTS: Oxygen uptake was similar (P > .05) during walking and stair climbing (13.7 vs. 13.5 mL/kg/min, respectively). The times to onset and to maximal claudication pain, as well as the peripheral hemodynamic measurements of ankle systolic pressure, ankle-to-brachial systolic pressure index, and foot transcutaneous oxygen tension were also similar between the two tests (P > .05). However, heart rate, systolic pressure, diastolic pressure, mean arterial pressure, and rate-pressure product values were lower during and following stair climbing than compared to walking (P < .05). CONCLUSION: Stair climbing may offer an advantage over treadmill walking for claudication patients because similar metabolic, claudication, and peripheral hemodynamic measurements are obtained with concomitantly less demand placed on the cardiovascular system. The stair climbing test was well tolerated and safely performed by each patient.

Aged↗

Functional improvements following StairMaster vs. treadmill exercise training for patients with intermittent claudication.

BACKGROUND: Although there have been many studies showing that exercise training is beneficial for patients with peripheral vascular occlusive disease (PVOD), there is little research comparing various modes of training. Previous studies showed that exercise tests performed on a StairMaster (StairMaster Sports/Medical Products, Kirkland, WA) produce responses similar to those elicited by treadmill tests. The purpose of this study was to compare these modes of exercise in a training program for patients with PVOD. METHODS: Of the 23 eligible individuals who began the exercise program, 11 did not complete the regimen due to various complications. Thus, 12 patients were randomly assigned to train for 12 weeks on either a StairMaster (n = 6) or a treadmill (n = 6). Patients underwent progressive and single-stage exercise tests on both exercise modalities before and after training. RESULTS: Mean exercise time before the onset of claudication pain for all tests rose significantly after training (P <.01), but greater improvements were seen on the specific training apparatus (i.e., treadmill training resulted in improvement in treadmill exercise performance with less improvement noted when tested on the StairMaster, and vice versa). Exercise time to maximal pain increased for the training apparatus only (P <.01). There were no changes in foot transcutaneous oxygen tension or the ankle-brachial blood pressure index. CONCLUSIONS: Both StairMaster and treadmill training improve the exercise capacity of PVOD patients. The training effect is most apparent for the specific training apparatus, but there is some cross-over improvement to the other exercise modality. Thus, StairMaster training is appropriate and can be part of the exercise prescription for treatment of these patients.

Aged↗