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Biomedical subjects

R Shah

Publications and source records attributed to R Shah.

At least 181 records · Page 10Linked to original sources
PubMed1983

Closure of post laryngectomy pharyngocutaneous fistula with sternocleidomastoid muscle flap.

A pharyngocutaneous fistula is an irritating and intractable complication following laryngectomy. These fistulae not only prolong the hospital stay of the patient but pose a potential danger of saliva eroding the carotid vessels. The sternocleidomastoid muscle has a number of uses in reconstructive surgery of the head and neck region and most small or medium sized defects can be closed by use of this muscle flap. This paper reports the use of this muscle flap for the closure of pharyngocutaneous fistulae in 4 cases. All the patients had large fistulae which had not healed after 8 weeks and had prior irradiation. There was no recurrent fistula in these cases.

Fistula↗
PubMed1982

Fluorescein appearance time curves. Continuous recordings of iris and anterior chamber dye flow contours.

Fluorescein appearance time (FAT) curves were recorded at 5-s intervals from the feline iris and anterior chamber using a modified video-frame store unit. Anterior chamber washout slopes were also recorded following intracameral injection. The iris FAT interval following intravenous injection was maximally 5 s. Passage of the dye bolus then appeared during the next 10 s, followed by a rapid (100-s) rise to maximum levels. In contrast to the iris, anterior chamber FAT curves recorded from the pupillary space showed an approximate two-minute delay after injection (mean = 1.92 +/- 0.360 minutes), followed by a gradual (20-minute) rise to maximum recordable levels. The mean anterior chamber washout rate following intracameral injection of 10(-6) g/mL of dye levels was 2.323% +/- 0.810%/min. There are potential applications of the method and a need for shorter recording intervals.

Animals↗
PubMed1982

Pain relief after abdominal surgery--a comparison of i.m. morphine, sublingual buprenorphine and self-administered i.v. pethidine.

One hundred and twenty-six patients undergoing upper and lower abdominal surgery were studied after operation to compare the analgesic effects of i.m. morphine, sublingual buprenorphine and self-administered i.v. pethidine by Cardiff Palliator. There were no significant differences between analgesic regimens in respect of subjective linear analogue pain scores or static and dynamic lung volumes assessed at 24 and 48 h after operation and 5 days after operation in patients who underwent upper abdominal surgery. Sublingual buprenorphine produced more nausea and sedation than the other two treatments, but the differences were not clinically important. However, it offered considerable advantages in terms of ease of administration.

Administration, Oral↗
PubMed1979

Study of the atherogenic dyslipoproteinemia induced by dietary cholesterol in rhesus monekys (Macaca mulatta).

Hypercholesterolemia was induced in adult male rhesus monkeys with a high-fat diet containing an elevated cholesterol level (0.5%). Plasma lipoproteins were chromatographically separated into four size populations (regions) that were subdivided by density until fractions with single electrophoretic mobilities were obtained. The region III lipoproteins (LDL) contained 80% of plasma cholesterol and were present in the highest concentration of all fractions. Their molecular weight was increased over that of controls so that each particle averaged 1.8 times the number of cholesteryl ester molecules as did control LDL. Region II lipoproteins, a heterogeneous group, were present in next highest concentration. Most were cholesteryl ester-rich, beta-migrating lipoproteins that overlapped the VLDL and LDL density ranges; apoB was the predominant apoprotein. One region II subfraction had pre beta 2 migration and the density range. 1.050 less than d less than 1.10. Another subfraction, cholesteryl ester-rich VLDL including only about 1% of plasma cholesterol, had pre beta 1 migration and apoB and apoC as the predominant apoproteins with no apoprotein E. Region I lipoproteins were larger sized, slow beta-migrating cholesteryl ester-rich VLDL that included 5% of plasma cholesterol. ApoB and apoE were the predominant apoproteins. Region IV lipoproteins (HDL) contained 4% of the plasma cholesterol; their concentration was decreased to about 1/3 of the control level. Atherogenic features of the diet-induced dyslipoproteinemia included the increased plasma concentrations and cholesteryl ester contents of the region I, II, and III lipoproteins in addition to the decreased HDL concentration.

Animals↗
PubMed1978

T-wave abnormalities of intermittent left bundle-branch block.

Ischemia is traditionally considered a cause of intermittent left bundle-branch block (LBBB), and some patients have right precordial T-wave inversion in the normally conducted beats. Clinical correlates of T-wave abnormalities were examined in 46 consecutive patients with intermittent LBBB. Thirty-three patients (72%) had at least transient right precordial (V-14) T-wave inversion suggesting ischemia in normally conducted beats. Seventeen such patients had no evidence of coronary heart disease, including five with normal arteriograms. During LBBB conduction, T-wave abnormalities (upright T-waves I, aVL, V5-6) were frequent (48%) and more common than among patients with permanent LBBB (p less than 0.005). The T-wave abnormalities during LBBB conduction occurred in the absence of coronary heart disease in nine patients, including two with normal arteriograms. Thus, right precordial T-wave inversion may result from recent LBBB itself, associated with T-wave abnormalities during the LBBB, in the absence of coronary artery disease.

Bundle-Branch Block↗
PubMed1977

Separation and characterization of plasma lipoproteins of rhesus monkeys (Macaca mulatta).

A group of 14 adult male rhesus monkeys was maintained on a low cholesterol-high fat diet. Periodically, animals were fasted and blood samples were taken for characterization of the plasma lipoproteins. Complete separation of individual plasma lipoprotein classes was not achieved by traditional sequential ultracentrifugation techniques. Rather, initial separation of lipoprotein classes according to size was effected and density centrifugation was used subsequently for further separation. At least six lipoprotein fractions were identified, each of which was unique as defined by the properties of size, density (d), and electrophoretic mobility. These lipoprotein fractions were characterized by determination of chemical compositions and apoprotein patterns. The lipoproteins present in highest concentration in these monkeys were designated as region IV lipoproteins. This fraction had alpha-migration on agarose electrophoresis, 1.063 < d < 1.225, and the size, composition, and apoprotein pattern characteristic of HDL. No fewer than three fractions were identified with densities that overlapped the 1.019 < d < 1.063 range. Of these, the fraction designated as region III lipoproteins was present in highest concentration, had beta-migration by agarose electrophoresis, a predominant B apoprotein, and a chemical composition and size characteristic of LDL. Two larger subfractions, identified as region II lipoproteins, were separated from each other at a density of 1.050 g/ml. Agarose electrophoresis showed that the fraction with d < 1.050 had a migration intermediate between beta and pre-beta. The chemical composition and apoprotein pattern were consistent with the possibility that these lipoproteins were remnants of VLDL catabolism. The fraction with d > 1.050, had pre-beta mobility and a size and composition similar to the Lp(a) lipoprotein in plasma of human beings. At least two VLDL subfractions, identified as region I and IIa lipoproteins, were found although both were present in very low concentrations. Region I lipoproteins were larger and contained relatively more cholesteryl ester and more of the apoproteins that migrated with the mobility of apo-B and arg-rich apoprotein in SDS-polyacrylamide gel electrophoresis. Some of the region I lipoproteins were beta-migrating by agarose electrophoresis. These results suggested the possibility that a beta-migrating VLDL was present in these normal animals.

Animals↗
PubMed1976

Intervention ventriculography. Comparative value of nitroglycerin, post-extrasystolic potentiation and nitroglycerin plus post-extrasystolic potentiation.

The comparative value of nitroglycerin (TNG), post-extrasystolic potentiation (PESP) and their combination (TNG + PESP) to unmask asynergic residual contraction was examined, each patient serving as his own control. Twelve of 13 hypokinetic zones improved both with TNG and PESP. One remained unchanged with either. Of 15 akinetic zones, four improved with both TNG and PESP, while ten remained unchanged. One akinetic zone, although improved with TNG, remained unchanged with PESP. Four dyskinetic zones did not change with either. Six asynergic zones responding to TNG alone demonstrated further augmentation with TNG + PESP. However, none of 13 TNG unresponsive zones improved with TNG + PESP. Thus, TNG, PESP, and TNG + PESP are each equally capable of unmasking asynergic residual contractile ability.

Cardiac Output↗
PubMed1976

Nitroglycerin and ventricular performance. Differential effect in the presence of reversible and irreversible asynergy.

The effect of nitroglycerin administration on left venticular performance relative to its ability to improve contraction of asynergic zones was examined in 66 patients with coronary artery disease, divided into those whose asynergic zones responded following nitroglycerin administration and those in whom no response was observed. In the responsive group with asynergy of more than one segment, the ejection fraction improved (P less than 0.001), while in the unresponsive group, it decreased (P less than 0.05). Similarly, in patients with one-segment asynergy, the responsive group exhibited a significant increase in ejection fraction P less than 0.001), while the unresponsive group showed no change. The stroke volume index remained unchanged in the responsive group with asynergy of more than one segment, while it decreased significantly (P less than 0.05) in the unresponsive patients. Left ventricular pressures and volumes changed to a similar degree after nitroglycerin administration in all of the patients, regardless of the responsiveness of asynergic zones. It is concluded that nitroglycerin administration results in a differential effect on total left ventricular performance depending on the responsiveness of asynergic zones.

Blood Pressure↗