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Biomedical subjects

A Kim

Publications and source records attributed to A Kim.

At least 145 records · Page 8Linked to original sources
PubMed1992

Crack cocaine use and sexual behavior among psychiatric inpatients.

Rises in both crack cocaine use and incidence of sexually transmitted diseases have been recently reported. In this study, we investigated the relationship between crack cocaine abuse and sexual behavior in 50 psychiatric inpatients. The relationship between crack use and sexual behavior is a very complicated one, influenced by many variables such as the dose of crack used, the user's preexisting sexuality, gender, and psychiatric illness. Results indicated that while most of the subjects developed sexual disinterest and dysfunction with prolonged crack cocaine use, some of them became more sexually promiscuous and consequently contracted more sexually transmitted diseases. The implications of these findings regarding transmission of HIV among crack cocaine users are discussed.

Adult↗
PubMed1992

Modulation of natural killer and lymphokine-activated killer cell cytotoxicity by lactoferrin.

Natural killer (NK) and lymphokine-activated killer (LAK) cell cytotoxic functions can be strongly augmented by the iron-carrier protein lactoferrin (LF). LF significantly enhances NK and LAK activities when added at the beginning of NK or LAK cytotoxicity assays. LF is effective in augmenting cytotoxic activities at concentrations as low as 0.75 microgram/ml, and higher concentrations of LF induce greater augmentation of NK and LAK. Iron does not appear to be essential for LF to increase NK and LAK, as depleting iron from LF with the chelator deferoxamine does not affect the capacity of LF to increase cytotoxicity. LF is known to have RNase enzymatic activity, and LF enhancement of NK and LAK can be blocked by RNA. However, LFs from two different sources with over 100-fold difference in RNase activity are equally effective in enhancing NK and LAK. Furthermore, purified non-LF RNase does not modulate NK or LAK activity and DNA is as effective as RNA in blocking LF augmentation of NK or LAK cytotoxicity. Therefore, the RNase activity is unlikely to be responsible for LF enhancement of the cytotoxicities. Newborn infants are known to have low NK activity and NK and LAK cells have been implicated in host defense against microbial infections. Thus, maternal milk-derived LF may have a role in boosting antimicrobial immunity in the early stages of life. In adults, LF released from neutrophils may enhance NK and LAK functions in the inflammatory process induced by microbial infections.

Cells, Cultured↗
PubMed1992

[Therapeutic occlusion of unilateral vertebral artery for unclippable aneurysms; special reference to postoperative brainstem ischemia].

Seven cases of unclippable vertebral artery aneurysms (3 dissecting, 1 fusiform, 2 saccular and 1 giant) are reported. Five of these had subarachnoid hemorrhage, one showed mass effect and the other was found incidentally. Trapping of the involved portion of the vertebral artery was performed in 4 cases, proximal clip occlusion in 2 and proximal balloon occlusion in 1. There were no operative deaths and no rebleeding, but brainstem ischemia developed in 4 cases, two being transient and two permanent. The ischemic complications were possibly due to; (a) hypoperfusion in the transient cases and (b) thromboenbolism, from the partially thrombosed giant aneurysm or thrombosis of the cul-de-sac vertebral artery, in the permanent ones. Preoperative temporary vertebral artery occlusion with an inflatable balloon or postoperative anticoagulant therapy should be considered in the management protocol.

Aortic Dissection↗
PubMed1991

Iontophoretic delivery of a series of tripeptides across the skin in vitro.

The iontophoresis of eight tripeptides, of the general structure alanine-X-alanine, has been measured across hairless mouse skin in vitro. The peptides were blocked (a) at the carboxyl terminus using the mixed anhydride reaction with t-butylamine and (b) at the amino terminus by acetylation with 14C-acetic anhydride. The nature of the central residue (X) was varied by selecting one of five neutral amino acids, two negatively chargeable moieties (aspartic and glutamic acids), and a positively chargeable species (histidine). Constant current iontophoresis at 0.36 mA/cm2, using Ag/AgCl electrodes, was performed for 24 hr in diffusion cells, which allowed both anode and cathode to be situated on the same (epidermal) side of a single piece of skin. Due to a combination of osmotic and electroosmotic forces, the anodal iontophoretic flux of neutral peptides was significantly greater than passive transport. Steady-state fluxes were not achieved, however, suggesting that time-dependent changes in the properties of the skin barrier may be occurring. Limited, further experiments confirmed that, on a 24-hr time scale, these changes were not fully reversible. The cathodal delivery of anionic permeants was well controlled at a steady and highly enhanced rate by the current flow. This behavior closely paralleled earlier work using simple negatively charged amino acids and N-acetylated amino acid derivatives. It appears that the normalized iontophoretic flux of these anionic species is independent of lipophilicity but may be inversely related to molecular weight. The positively charged peptide, Ac-Ala-His-Ala-NH(But), showed greater anodal iontophoretic enhancement when delivered from a donor solution at pH 4.0 than from a solution at pH 7.4.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1991

Alpha-1 antitrypsin deficiency in a patient with widespread prurigo nodularis.

Skin lesions associated with alpha 1-antitrypsin deficiency are becoming better defined and understood. Deficiency in this major antiproteinase, which neutralizes multiple proteolytic enzymes ranging from collagenases and elastases to trypsin and chymotrypsin, thus results in significant tissue autodigestion. This anti-proteinase is secreted by activated lymphocytes and macrophages, suggesting the existence of homeostasis which titrates the release of proteolytic enzymes by these cells, and the adequate neutralization of these proteases in order to prevent excessive tissue autodigestion each time these inflammatory cells are activated. We report a patient with alpha 1-antitrypsin deficiency who, following insect bites and cellulitis developed widespread itching and scratching, leading to widespread lesions of prurigo nodularis. The colonization of his multiple skin lesions with Staphylococcus aureus and the release of potent T cell mitogens, such as Protein A and enterotoxin A from the bacterial cell membrane may have resulted in the release of additional proteolytic enzymes by the activated lymphocytes and macrophages, without the concomitant secretion of alpha 1-antitrypsin with subsequent aggravation of his pruritus. These concepts are supported by electron microscopic evidence of excessive tissue autodigestion, and by immunocytochemical data identifying the presence of T helper and T cytotoxic/suppressor lymphocytes as well as macrophages within the upper dermis.

Humans↗
PubMed1991

The specific hydraulic conductivity of bovine serum albumin.

Previous studies of extracellular matrix hydraulic conductivity have characterized the flow resistance of glycosaminoglycans, proteoglycans and collagen. This work focuses on serum albumin, present in significant quantities in many connective tissues, but not previously considered for its role in determining connective tissue flow resistance. The specific hydraulic conductivity of bovine serum albumin solutions, as a function of concentration, was calculated from sedimentation and ultrafiltration data available in the literature. A rigid particle hydrodynamic model compared favorably with these results. Experimental measurements on an albumin ultrafiltration cell were in agreement with this model (within experimental error); furthermore, the experimental data confirmed the theoretical prediction that there is no (or negligible) pressure drop through the concentration polarization layer. Use of the hydrodynamic model for albumin specific hydraulic conductivity with literature values for the hindrance of albumin when passing through a glycosaminoglycan (GAG) matrix allows an estimate of the relative importance of the albumin on tissue hydraulic conductivity: in non-cartilaginous tissues with moderate GAG concentrations, tissue levels of albumin can generate flow resistance effects comparable to those of the GAGs, although well less than the flow resistance of these tissues.

Animals↗
PubMed1990

Tannic-acid staining material on high endothelial venules and lymphocytes in skin and peripheral lymph nodes in Staphylococcus aureus-associated erythroderma.

The recognition and binding of glycoprotein receptors on lymphocytes to specific antigens present on high endothelial venules (HEV) precedes the egress of lymphocytes from the blood stream into the tissues. In this paper, we report the presence of HEVs with tannic-acid staining material (TASM+ HEVs) in Staphylococcus aureus-associated erythroderma, which allow the migration of CD8+ lymphocytes from the bloodstream into the epidermis. TASM positivity is also expressed on lymphocytes within the regional lymph nodes, and by intravascular lymphocytes prior to leaving the TASM+ HEV. It is proposed that TASM positivity may represent a molecule, which may function in binding lymphocytes to HEVs prior to egress from the HEV. (TASM is lost from lymphocytes after leaving the HEVs). The expression of TASM positivity may form an essential part of the CD8+ lymphocyte-HEV recognition system, and may be the means whereby CD8+ lymphocytes generated in the regional lymph nodes by various mitogens (in this case by staphylococcal mitogens) may 'home' to specific sites within the epidermis. TASM positivity on both the HEVs and lymphocytes may serve as a convenient marker of such a system.

Dermatitis, Exfoliative↗
PubMed1990

Blood conservation in major orthopedic surgery.

During an eight-year period, intraoperative autotransfusion was performed in 1922 operations. There were 476 primary hip arthroplasties, 1017 revision hip arthroplasties, 339 spinal procedures, and 90 vascular cases. There were no known complications related to autotransfusion in any of the cases. With proper technique, red cell salvage is approximately 58% effective, and intraoperative blood loss can be reduced by that amount. The first four years' experience with the preoperative autogeneic blood program is as follows. Using a combined program of predonation and primary hip arthroplasty, 72% of the revision hip arthroplasties and 81% of the spinal instrumentations required only autologous blood. A combined program of autologous donation and intraoperative autotransfusion is an excellent alternative to allogeneic blood replacement and a means of eliminating transfusion-related disease.

Blood Preservation↗
PubMed1989

Regional cerebral blood flow in the persistent vegetative state.

Regional cerebral blood flow (CBF) in eight patients in a persistent vegetative state was measured and compared with that in five healthy volunteers. The patients were classified into three groups: Group 1 (locked-in syndrome) consisted of a single patient, Group 2 (typical vegetative state) of five patients, and Group 3 (prolonged coma) of two patients. CBF was measured early after onset by single photon emission computed tomography with 123I-N-isopropyl-p-iodo-amphetamine and/or 99mTc-hexamethyl-propyleneamine oxime. The regions of interest (ROIs) were the bilateral frontal, temporal, parietal, occipital, and cerebellar areas and basal ganglia. The values obtained in these areas were averaged, and the ratio for each ROI [(the value in the ROI/the mean value) x 100] was calculated. "Hyperfrontal distribution" of CBF was found to be rare in both the normal condition and the vegetative state. Higher CBF values were noted in the left than in the right frontal area in four of the five volunteers but in only four of the eight patients. CBF distribution in the frontal lobe was characteristic for each group: Group 1 showed high CBF bilaterally, although the elevation was statistically significant only on the right side, and Group 3 exhibited significantly low values. In Group 2, CBF was variable but, for the most part, within normal limits. Awareness was closely correlated with frontal lobe function and alteration of CBF in the frontal region.

Adult↗
PubMed1989

Efficacy of low-dose metoprolol in neuroleptic-induced akathisia.

Recent studies have shown that the beta-blockers can be effective treatments for neuroleptic-induced akathisia. However, the relative contributions of beta-1 versus beta-2 blockade to the therapeutic effect of beta-blockers remains unclear. We treated nine patients who had neuroleptic-induced akathisia with low doses (25-100 mg/day) of the beta-blocker metoprolol. At these doses metoprolol causes selective blockade of beta-1 receptors. Seven patients improved after metoprolol; no further substantial changes were seen after subsequent treatment with propranolol. This finding suggests that neuroleptic-induced akathisia can be improved by selective beta-1 blockade.

Adult↗
PubMed1989

Akathisia: selective beta-blockers and rating instruments.

beta-Blockers, particularly propranolol, have been shown to be an effective treatment for neuroleptic-induced akathisia (NIA). To examine the relative contribution of beta-1 and beta-2 receptor blockade to the therapeutic effect of propranolol, we studied a beta-1 selective agent (low dose metoprolol) and a beta-2 specific blocker (ICI 118,551). Both agents ameliorated NIA. To further evaluate instruments for quantifying NIA we compared (a) two sets of clinical ratings during the metoprolol study and (b) clinical and electromechanical ratings of NIA during the ICI 118,551 study. The changes in clinical ratings of NIA after metoprolol were similar for most patients; however, the changes in electromechanical and clinical ratings after ICI 118,551 were similar in less than half of the patients studied.

Adrenergic beta-Antagonists↗
PubMed1988

Suppression of lymphokine-activated killer induction by neutrophils.

Peripheral blood polymorphonuclear neutrophils (PMN) suppressed the induction of PBL lymphokine-activated killer (LAK) function by rIL-2 in vitro. The suppression depended on the concentration of PMN in the IL-2 culture, and required intact PMN. However, PMN did not require treatment with immunoregulators such as IL-2, LPS, or TNF to express the suppressive activity, and no direct contact with PBL was needed for the suppression. Addition of anti-TNF antibodies had no effect on the suppression, suggesting that no endogenous TNF in the culture was involved in the suppression. PMN did not inhibit LAK function by preventing utilization of IL-2 by PBL or by selective depletion of NKH-1+ cells which constitute the majority of LAK precursors in PBL. The suppression was reversed by superoxide dismutase but not by catalase, suggesting that superoxide anion, not hydrogen peroxide, was involved in the suppression. No other suppressive factor was detectable in PMN culture supernates. Our results of PMN regulating LAK induction in vitro suggest that PMN may have a role in determining the outcome of immunotherapy with IL-2 in vivo.

Binding, Competitive↗
PubMed1987

Neurotransmitters and memory: role of cholinergic, serotonergic, and noradrenergic systems.

In Alzheimer's disease (AD), pathological changes are found in the basal forebrain cholinergic system (BFCS), serotonergic raphe (RA), and noradrenergic locus coeruleus (LC) systems. The present study was designed to determine the extent to which selective damage in each of these systems individually could produce an impairment of memory, one of the clinical symptoms of AD. Rats were given selective lesions by injecting ibotenic acid into the nucleus basalis magnocellularis and medial septal area (i.e., BFCS); 5,7-dihydroxytryptamine into the medial and dorsal RA; and 6-hydroxydopamine (6-OHDA) into the LC or by ip injections of (2-chloroethyl)N-ethyl-2-bromobenzylamine HCl (DSP4). Levels of choline acetyltransferase (ChAT), norepinephrine, and serotonin verified lesion effectiveness and selectivity. Chronic changes in serotonergic-2 and beta-adrenergic receptors were also determined. Rats were tested in a delayed spatial alternation in a T-maze. BFCS lesions impaired choice accuracy with intertrial delays of 5, 30, and 60 s. RA lesions or DSP4 injections impaired choice accuracy only when the intertrial delay was 60 s. LC lesions (by 6-OHDA) did not impair choice accuracy at any delay. The results suggest that the pathological changes in the BFCS and RA are sufficient to produce the types of memory impairments associated with dementia, but the quantitative effects of pathology in these two systems are different.

Animals↗
PubMed1985

Effects of purified ginseng saponins on multilamellar liposomes.

To elucidate the mode of interaction between purified ginseng saponins and liposomes, the effects of ginseng saponins at concentrations below and above their critical micelle concentration on the osmotic behavior of liposomes were observed. Liposomes composed of egg phosphatidylcholine (PC), phosphatidic acid (PA) and/or cholesterol (Ch) behave as an ideal osmometer and this activity was described by the linear relationship between (1/A450)3/2 and Cin/Cout. Total saponin prepared from the lateral roots of ginseng cultivated in Korea interacted with multilamellar liposomes and prevented them from behaving as an ideal osmometer. 20-S-Protopanaxadiol saponin showed similar activity but 20-s-protopanaxatriol saponin had weak activity. Ginsenoside Rb1 whose genin is 20-S-protopanaxadiol, disturbed osmotic behavior of Ch-free liposomes but not Ch-containing liposomes as monomers and lyzed both liposomes as micelles. Rg1 whose genin is 20-S-protopanaxatriol, showed no activity on liposomes with or without Ch. It can be suggested that ginseng saponins may interact with and destroy liposomal membranes and that structure of sugar moiety is an important factor to their activities. Ch is not a target in this interaction but suppresses the activity of ginseng saponins.

Brassica↗
PubMed1985

Combined thiotepa and mitomycin C instillation therapy for low-grade superficial bladder tumor.

Fifteen patients with superficial low-grade bladder tumors were treated with combined thiotepa and mitomycin C instillation as definitive therapy. The amount of both thiotepa and mitomycin C used in each instillation in the presenting protocol was one half the conventional dose of either used alone. Patients with multiple bladder tumors, bladder tumors inaccessible to endoscopic resection, or lesions too extensive to completely resect, or with medial contraindications for endoscopic resection procedures, were included in these studies. No serious adverse effect was revealed in these 15 patients. Ten of the 15 patients (66.7%) had a complete response and 4 (26.7%) had a partial response. One patient (6.6%) did not respond to this regimen. This protocol seems to provide a therapeutic modality that is more effective than conventional single-drug therapy, less toxic than thiotepa used alone, and less expensive than mitomycin C used alone.

Aged↗
PubMed1985

Ultrastructural morphometric analysis of normal human lymphocytes stimulated in vitro with mitogens and antigens.

In the present study the authors attempt to experimentally produce the characteristic cerebriform appearance of Sézary cells from normal cells by stimulation in vitro with a variety of mitogens and antigens. Lymphocytes were stimulated with the mitogens phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen and the antigens spherulin, Candida, and herpes simplex virus Type I. In vitro blast transformation was measured in tritiated thymidine uptake microculture systems. Nuclear contours were morphometrically analyzed with the use of a computerized planimeter. An exhaustive search for Sézary-type cells did not reveal any nuclear profiles that were highly convoluted. The lowest form factor value obtained from the stimulated cultures was 0.14. This value represents 14% of a circle. All stimulated cultures analyzed morphometrically showed significant blast transformation. There was no correlation between the degree of stimulation and the nuclear contour values. An analysis of mean form factor values from ten separate lymphoid populations revealed that neither mitogens nor antigens had any effect on increasing the nuclear irregularity of lymphoid cells. One PHA-stimulated culture, in fact, had less irregular nuclear contours than the 3-day unstimulated control cells. The difference in these means was statistically significant (P less than 0.05). In addition, morphometric analysis of 73 published electron micrographs of human lymphoid cells from a variety of clinical and experimental conditions showing irregular nuclear contours revealed that only 5% had nuclei that were more irregular than the most convoluted nuclei analyzed from lymphocytes stimulated in vitro in the present study. The authors have shown that mitogen- and antigen-stimulated cells do not display the highly irregular nuclear outlines commonly seen in the Sézary syndrome and mycosis fungoides and emphasize the need for more objective analysis of Sézary-like nuclear profiles to determine their specificity.

Antigens↗
PubMed1983

An ultrastructural evaluation of the cell organelle specificity of the uranaffin reaction in two human endocrine neoplasms.

The organelle specificity of the uranaffin reaction was determined by subjecting two human neoplasms (a pheochromocytoma and islet cell carcinoma) to four different experimental conditions. In Uranaffin Procedure (UP) I, fixed tissue was immersed in 0.9% sodium chloride (NaCl) before reacting with 4% uranyl acetate (pH 3.9) for 24 hours. In UP II, the tissue was prepared as in UP I with the exception that the tissue was immersed in uranyl acetate for 48 hours. In UP III, fixed tissue was prepared as in UP I with the exception that tissue was immersed in 0.1M cacodylate buffer (pH 7.2) instead of 0.9% NaCl. In UP IV, fixed tissue was prepared as in UP III with the exception that the tissue was immersed in uranyl acetate for 48 hours instead of 24 hours. When UPs I and II were utilized, only three cell organelles showed electron-dense reactivity: the nucleus, ribosomes, and cytoplasmic neurosecretory-like granules. In the nucleus, the nuclear chromatin, nucleolus, interchromatinic granules and perichromatinic granules were intensely stained. The reaction product in all of the uranaffin-positive organelles had a finely granular appearance. When fixed tissue was immersed in cacodylate buffer instead of isotonic saline, a non-specific reactivity was observed. The reaction product in some areas had a distinct crystalline appearance and filled some areas of the cytosol, the cisternae of the endoplasmic reticulum, the Golgi apparatus, the perinuclear cisternae, the nucleus, nucleolus, mitochondria, neurosecretory-like granules and larger lysosome-like bodies. There was a statistically significant (p less than 0.05) increase in the number of uranaffin-positive granules/mu2 when both endocrine neoplasms were reacted with uranyl acetate for 48 hours instead of 24 hours. The increase in uranaffin-positive granules using UP II did not result in an increase in non-specificity of the staining reaction.

Adenoma, Islet Cell↗