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Biomedical subjects

R Khosla

Publications and source records attributed to R Khosla.

14 recordsLinked to original sources
PubMed2000

Constrained scaling: the effect of learned psychophysical scales on idiosyncratic response bias.

We report seven experiments in which subjects were trained to respond with numbers to the loudness of 1000-Hz pure tones according to power functions with exponents of 0.60, 0.30, and 0.90. Subjects were then presented with stimuli from other continua (65-Hz pure tones or 565-nm lights varying in amplitude) and were asked to judge the subjective magnitude of these stimuli on the same numerical scale. Stimuli from the training continuum were presented, with feedback, on every other trial in order to maintain the trained scale. Except for the 0.90 scale, subjects readily learned the predetermined scales and were able to use them to judge the non-training stimuli with group results consistent with those usually reported. Also, in contrast to the usual magnitude estimation results, these results produced extremely low levels of intersubject variability. We argue that such learned scales can be used as "rulers" for measuring perceived magnitudes, according to a common unit.

Auditory Perception↗
PubMed2000

Somatization.

Explore the source record for details and available documents.

Adult↗
PubMed1999

Heat-related illnesses.

The majority of clinicians will encounter patients with heat-related illness in one form or the other. Early recognition and management are important to prevent morbidity and mortality. In children and elderly, the clinical signs may be subtle and in such situations a sound knowledge of heat-related illnesses is crucial. Besides diagnosing and treating heat-related illnesses, it is equally important to know how to prevent them as they are easily preventable.

Acclimatization↗
PubMed1999

Streptogramins: a new class of antibiotics.

Streptogramin antibiotics represent a unique class of antibacterials in the each member of the class consists of at least 2 structurally unrelated molecules: group a streptogramins (macrolactones) and group B streptogramins (cyclic hexadepsipeptides). Both group A and group B streptogramins inhibit protein synthesis at the ribosomal level, and they act synergistically against many isolates their combination generating bactericidal activities and reducing the possibility of emergencies of resistant strains. The mechanisms of acquired resistance to group B streptogramins remain unaffected by target modifications and active efflux. The pharmacokinetic parameters of group A and group B streptogramins in blood are quite similar. In addition, both the A and B group penetrate and accumulate in macrophages and in the bacterial gegetations of experimental endocarditis. Until recently, the complex and irregular composition of naturally occurring pristinamycin and virginiamycin, as well as the unavailability of soluble forms, have limited the clinical development of streptogramins. The synthesis of water soluble derivatives of pristinamycin IA and IIB has now allowed the development of injectable streptogramins with fixed compositions. This unique class of antibacterials will have a significant clinical impact in a world of increasing multidrug resistance affecting the Gram-positive cocci, especially staphylococci and pneumococci. The absence of cross-resistance to macrolides in many of these isolates and the rapid antibacterial killing against these species bright future for this class of antibiotics.

Anti-Bacterial Agents↗
PubMed1998

Simvastatin-induced lupus erythematosus.

We report the case of a 79-year-old man who had onset of fatigue, myalgia, and pleuritic chest pain 3 months after initiation of therapy with simvastatin. He had signs of pleuropericarditis due to simvastatin-induced lupus erythematosus. This should alert clinicians to this possible adverse effect of simvastatin and other statins.

Aged↗
PubMed1998

Opioid receptor mediated anticonvulsant effect of pentazocine.

Intraperitoneal (i.p.) administration of (+/-) pentazocine (10, 30 & 50 mg/kg), a Sigma opioid agonist, resulted in a dose dependent anticonvulsant action against maximal electroshock seizures in mice. This anticonvulsant effect of pentazocine was not antagonized by both the doses of naloxone (1 and 10 mg/kg) suggesting thereby that its anticonvulsant action is probably mediated by Sigma opiate binding sites. Its anticonvulsant effect was potentiated by both the anticonvulsant drugs viz. diazepam and diphenylhydantoin. Morphine, mu opioid agonist, on the other hand, failed to protect the animals against maximal electroshock seizures when it was given in doses of 10-40 mg/kg body wt.

Analgesics, Opioid↗
PubMed1997

Cholecystectomy alleviates acalculous biliary pain in patients with a reduced gallbladder ejection fraction.

BACKGROUND: We sought to determine whether a reduced gallbladder ejection fraction, (GBEF) ascertained by cholecystokinin-cholescintigraphy (CCK-CS), predicts symptomatic improvement after cholecystectomy. METHODS: Medical records of patients who had had CCK-CS as well as negative results of gallbladder ultrasonography were reviewed, and patients were contacted by telephone to determine whether they had benefited from cholecystectomy. RESULTS: There were 35 patients (33 female, 2 male) who had a decreased GBEF. Cholecystectomy was done in 30, of whom 20 (67%) had resolution of pain, 8 (27%) had partial improvement, and 2 (7%) had no change. The 5 who declined cholecystectomy included none (0%) who were pain free, 2 (40%) who had partial improvement, and 3 (60%) who had no change. The clinical outcome of the two groups was significantly different. There were 14 patients (10 female, 4 male) with a normal GBEF. The 2 patients who had cholecystectomy were asymptomatic. Of the 12 patients who did not have cholecystectomy, 9 (75%) were asymptomatic, 1 (8%) had some improvement, and 2 (17%) had no change. CONCLUSIONS: Cholecystectomy is indicated for patients with acalculous biliary pain and reduced GBEF, since symptoms will likely resolve with surgery and will persist without it. Cholecystectomy for patients with a normal GBEF should be considered only after failure of a nonoperative trial, since improvement usually occurs over time.

Adolescent↗
PubMed1988

Gastric emptying of large single unit dosage forms.

The gastrointestinal transit of two single unit dosage forms has been followed in healthy subjects under different feeding conditions. Transit was affected by the size of the meal administered. When two tablets were given concurrently they often emptied from the stomach at or about the same time, but in a number of cases the two units were seen to empty at widely different times.

Adolescent↗
PubMed1987

Investigation of the gastrointestinal transit and in vivo drug release of isosorbide-5-nitrate pellets.

An oral formulation of controlled-release isosorbide-5-nitrate pellets has been used to investigate the location of pellets in the gastrointestinal (GI) tract and, in parallel, to measure the drug absorption from these locations. Using the method of gamma scintigraphy the transit times and spreading of pellets in the GI tract have been determined. The method of numeric deconvolution was applied to calculate the drug input into the systemic circulation. The results indicate that a well-absorbed substance such as isosorbide-5-nitrate is absorbed from the stomach and small intestinal in a manner that is controlled by the properties of the pellets. Drug absorption is reduced in the colon. The average transit time from mouth to colon is 6 to 8 hr, which represents the maximum acceptable time for drug release for this oral controlled-release preparation. Taking into account these relations an isosorbide-5-nitrate pellet formulation with a bioavailability of 84% has been developed that maintained the minimal therapeutic plasma level for more than 16 hr after application.

Delayed-Action Preparations↗
PubMed1987

The effect of polycarbophil on the gastric emptying of pellets.

The influence of the putative bioadhesive, polycarbophil, on the gastric emptying of a pellet formulation, has been investigated in three fasted subjects. The pellets were radiolabelled with technetium-99m. Gastric emptying was measured using the technique of gamma scintigraphy. The pellets emptied from the stomach rapidly and in an exponential manner. Polycarbophil did not retard the gastric emptying of the pellets.

Acrylic Resins↗
PubMed1987

Walk-in clinic and diagnostic stability.

One hundred and six consecutively seen psychiatric patients who had undergone detailed evaluation had their diagnosis compared with that arrived at in a walk-in evaluation one week to one month prior to the index evaluation. There was a diagnostic change in 21 cases and a change in drugs in 14. The pitfalls of this method for administering rapid efficient psychiatric care in countries with inadequate psychiatric manpower are highlighted.

Adult↗
PubMed1984

Crohn's disease and pregnancy.

Infertility and the outcome of pregnancy has been examined in 112 married women with Crohn's disease who were below the age of 45 years. Fifty four patients were available for study. The infertility rate (12%) was similar to that seen in the general population. Patients who had active disease at the time of conception continued to have symptoms and they mostly failed to go into satisfactory remission despite therapy. Furthermore, there was a high rate (35%) of spontaneous abortion in this group. In contrast, patients whose disease was in remission at the time of conception had a normal pregnancy and, in the majority, the Crohn's disease remained quiescent.

Abortion, Spontaneous↗