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Biomedical subjects

P Kim

Publications and source records attributed to P Kim.

106 records · Page 6Linked to original sources
PubMed1987

Production of uric acid in cerebrospinal fluid after subarachnoid hemorrhage in dogs: investigation of the possible role of xanthine oxidase in chronic vasospasm.

Based on accumulating evidence of the role of xanthine oxidase (XO) in generating oxygen free radicals and causing tissue damage during ischemia, we examined the possible role of XO in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). After inducing SAH in dogs by two autologous blood injections 2 days apart, chronic vasospasm of the basilar artery was reliably produced. There was a 3.5-fold elevation in uric acid (UA), the product of XO, in the cerebrospinal fluid (CSF) of these animals. Parenteral administration of allopurinol (i.v., 25 mg/kg, every 6 hours), a specific blocker of XO, successfully abolished the elevation in CSF uric acid levels due to SAH. However, angiographic vasospasm measured on Day 7, morphological changes observed by electron microscope, and elevated CSF prostaglandin levels were not altered by the treatment. It can be concluded that the observed activation of the enzyme XO, which is a well-known source of oxygen free radicals in ischemia in various organs, is not playing a major role in the pathogenesis of chronic cerebral vasospasm in this animal.

Allopurinol↗
PubMed1985

Hemiparesis caused by vertebral artery compression of the medulla oblongata. Case report.

The case is reported of a patient with progressive left hemiparesis due to vascular compression of the medulla oblongata. Metrizamide computerized tomography cisternography revealed that the left vertebral artery was compressing and distorting the left lateral surface of the medulla. Compression was surgically relieved and symptoms improved postoperatively. Neurological and symptomatic considerations are discussed in relation to the topographical anatomy of the lateral corticospinal tract.

Brain Diseases↗
PubMed1984

Observations on synkinesis in patients with hemifacial spasm. Effect of microvascular decompression and etiological considerations.

In 95 patients with hemifacial spasm, synkinetic actions were measured objectively using electromyographic examination of the blink reflex and impedance audiometry. Abnormal synkinesis between the orbicularis oculi and the orbicularis oris muscles was recorded in 93% of cases, while synkinesis between the stapedius muscle and the facial muscles was recorded in 87%. Neither of these effects could be demonstrated on the unaffected side. The examinations were performed before and after microvascular decompression in 66 cases. Rapid disappearance of synkinesis, often within 10 days, was observed after the relief of vascular compression in 81% of patients who had not undergone previous peripheral facial nerve block procedures. These findings indicate that the synkinesis seen in hemifacial spasm is essentially a reversible condition, and suggest that axonal ephaptic conduction at the vascular compression site plays an important role in the pathophysiological mechanism of hemifacial spasm.

Acoustic Impedance Tests↗
PubMed1978

Electrophysiological characteristics of renorenal reflexes in the cat.

1. Experiments were done in anaesthetized, paralysed and artificially ventilated cats to determine the fibre composition of renal nerves and to study the functional characteristics of reflex responses recorded in efferent renal nerves during electrical stimulation of contralateral and ipsilateral afferent renal nerves. 2. Renal nerves were found to contain three afferent fibre groups (Abeta, Adelta and C); the majority of these fibres reach the sympathetic chain through the least splanchnic nerve. Efferent sympathetic nerves to the kidney were found to originate from the greater, lesser and least splanchnic nerves through a synapse in the coeliac ganglion. 3. Two contralateral renorenal reflex responses were demonstrated during selective stimulation of renal afferent A and C fibres. The first (A renorenal reflex) was elicited by stimulation with trains of pulses at low voltage and high frequency (200 Hz), had an onset latency of approximately 100 msec and was followed by post-excitatory depression. The second (C renorenal reflex) was demonstrated by trains of pulses at high voltage and low frequency (20--30 Hz), had an onset latency of approximately 350 msec and was also followed by post-excitatory depression. 4. Ipsilateral renorenal reflexes with characteristics similar to the contralateral reflexes were also demonstrated. 5. Renorenal reflexes were abolished by destruction of the spinal cord and administration of nicotine sulphate (5--20 mg/kg, i.v.), but were not affected by bicuculline (0.4 mg/kg, i.f.). 6. The significance and the physiological role of these renorenal reflexes as well as their pathways within the central nervous system remain to be determined.

Animals↗
PubMed1976

Health care for elderly Americans: evaluation of an adult day health care model.

This study was designed to analyze the cost and effectiveness of a day care program for the elderly. An experimental group of adult day care participants was compared with a control group of elderly people living in the community. The two groups were evaluated in terms of levels of physical and emotional functioning, behavioral independence in activities of daily living, institutionalization, interpersonal relationships, and re-establishment of life styles. Statistical tests of difference were used to determine if the two groups had improved or were maintained over the six-month study period (November 1973 to March 1974). The experimental group showed improvement and differed significantly from the control group in the areas of emotional functioning, self-maintenance, and interpersonal relationships. No significant differences were found in satisfaction with life styles for either group. The experimental group was somewhat, but not significantly, deficient in independence in daily living activities. Composite analysis of six combined scales indicated that the experimental group inproved in level of functioning over the study period while the control group regressed. Cost analysis of the Lexington Center indicates that adult day care services cost +12.99 per participant per day.

Activities of Daily Living↗
PubMedDate not supplied

Intratesticular steroid levels and their hormonal control.

Litter-mate adult male rats were treated with daily intramuscular injections of ACTH (10.5 micrograms), dexamethasone (2.0 mg), ethynyl estradiol (1.7 micrograms) and hCG (5 IU) for three consecutive days. The animals were sacrificed on the fourth day and the intratesticular and peripheral plasma steroid levels were analyzed. The steroids measured by radioimmunoassay included pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone, progesterone, 17-hydroxyprogesterone, androstenedione, testosterone and dihydrotestosterone. In addition, the sulphoconjugated forms of pregnenolone, dehydroepiandrosterone, testosterone and dihydrotestosterone were estimated in the peripheral blood. The administration of ACTH diminished the intratesticular levels of all steroids studied. Also dexamethasone and ethynyl estradiol treatment suppressed all intratesticular steroid levels, except that of pregnenolone (the former) and of 17-hydroxyprogesterone (the latter). The suppressive effect of ethynyl estradiol was strongest on the levels of the delta 5-steroids and that of dexamethasone on the delta 4-steroids; the latter was significantly stronger than the effect of ACTH. The stimulatory effect of hCG was limited to the metabolism of progesterone and was restricted to the sequence: 17-hydroxyprogesterone----androstenedione----testosterone---- dihydrotestosterone. Dexamethasone-suppression, and hCG-stimulation of the intratesticular levels of delta 4-steroids, was mirrored by corresponding changes in the peripheral plasma levels, with the exception of the plasma levels of androstenedione which were not influenced by any of the treatments studied. Also the suppression of intratesticular testosterone and dihydrotestosterone levels by ACTH, dexamethasone, or ethynyl estradiol was closely reflected by their plasma levels both in the unconjugated and sulphoconjugated forms. On the hand, the administration of ACTH diminished the intratesticular levels of pregnenolone and progesterone but significantly increased those in the plasma. Moreover, both ACTH and ethynyl estradiol reduced the levels of all delta 5-steroids in testicular tissue, but not in the peripheral plasma, although they decreased the circulating levels of pregnenolone sulphate and dehydroepiandrosterone sulphate. The data are interpreted as suggesting that the hormonal agents studied interfere with testicular steroidogenesis through different mechanisms.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Phenolic anti-inflammatory antioxidant reversal of Abeta-induced cognitive deficits and neuropathology.

Both oxidative damage and inflammation have been implicated in age-related neurodegenerative diseases including Alzheimer's Disease (AD). The yellow curry spice, curcumin, has both antioxidant and anti-inflammatory activities which confer significant protection against neurotoxic and genotoxic agents. We used 22 month Sprague-Dawley (SD) rats to compare the effects of the conventional NSAID, ibuprofen, and curcumin for their ability to protect against amyloid beta-protein (Abeta)-induced damage. Lipoprotein carrier-mediated, intracerebroventricular infusion of Abeta peptides induced oxidative damage, synaptophysin loss, a microglial response and widespread Abeta deposits. Dietary curcumin (2000 ppm), but not ibuprofen, suppressed oxidative damage (isoprostane levels) and synaptophysin loss. Both ibuprofen and curcumin reduced microgliosis in cortical layers, but curcumin increased microglial labeling within and adjacent to Abeta-ir deposits. In a second group of middle-aged female SD rats, 500 ppm dietary curcumin prevented Abeta-infusion induced spatial memory deficits in the Morris Water Maze and post-synaptic density (PSD)-95 loss and reduced Abeta deposits. Because of its low side-effect profile and long history of safe use, curcumin may find clinical application for AD prevention.

Amyloid beta-Peptides↗
PubMedDate not supplied

High production of D-tagatose, a potential sugar substitute, using immobilized L-arabinose isomerase.

An L-arabinose isomerase of Escherichia coli was immobilized using covalent binding to agarose to produce D-tagatose, a bulking sweetener that can be economically used as a sugar substitute. The immobilized L-arabinose isomerase stably produced an average of 7.5 g-tagatose/L.day for 7 days with a productivity exceeding that of the free enzyme (0.47 vs 0.30 mg/U.day). Using a scaled-up immobilized enzyme system, 99.9 g-tagatose/L was produced from galactose with 20% equilibrium in 48 h. The process was repeated two more times with production of 104.1 and 103.5 g-tagatose/L. D-Tagatose production using an immobilized L-arabinose isomerase has a high potential for commercial application.

Aldose-Ketose Isomerases↗
PubMedDate not supplied

Kinetic observational exophthalmometry: a simple clinical method of assessing the relative axial positions of the eyes.

A simple clinical method for detecting the presence of unilateral proptosis or enophthalmos is described. It is important that in a patient with orbital disease, a detailed ophthalmic and orbital history be taken and a careful clinical evaluation be performed. In the clinical assessment of such a patient, it is also essential to determine the presence of any asymmetry of eye position after excluding any asymmetry in eye size or in the skeletal structure of the face. Observation of the patient's head from above and noting the relative positions of the two eyes has been the traditional method in the clinical assessment of proptosis. We believe that this method of assessment of proptosis has not been adequately described or fully exploited in the past. This paper describes an extension of the same technique. It involves the examiner making the observation from above while slowly moving the patient's head passively from a position of neck flexion to one of neck extension, and then noting which eye in a patient comes into view first. We believe that this kinetic technique provides an accurate method of noting any asymmetry in eye position in relation to the supraciliary ridge. It should therefore prove to be a clinically useful method in the initial assessment of a patient with suspected ocular displacement.

Diagnostic Techniques, Ophthalmological↗