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Biomedical subjects

E H Kim

Publications and source records attributed to E H Kim.

68 records · Page 4Linked to original sources
PubMed1989

Thrombocytopenic purpura in parenteral drug abusers.

Twenty heterosexual men considered to be at risk for developing the acquired immunodeficiency syndrome because of parenteral drug abuse underwent splenectomy for steroid resistant thrombocytopenia during a recent 34 month period. Increased bruising, ecchymoses petechiae and occasional epistaxis, together with markedly elevated levels of platelet associated immunoglobulin, were characteristic findings. There was no operative mortality, and the morbidity rate was 25 per cent. Accessory spleens were removed in five patients. Platelet counts rose to normal levels or higher postoperatively in all patients, and this response was sustained for one month to 25 months in 13 of 15 patients for whom this information is available. Thrombocytopenia in parenteral drug abusers can be safely and promptly corrected by splenectomy, and although more information is needed, it seems likely that this response will be maintained in most of these patients.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Chronic digitalis administration alters mesenteric vascular reactivity.

To characterize any digitalis-induced differences in intestinal blood flow autoregulation, we studied the circulatory responses of the rat intestine in control (n = 7) and chronically digitalized (n = 7) animals. Data were generated from denervated isoperfused small intestinal preparations. Arterial pressure, venous pressure, and oxygen consumption were continuously monitored. Determinations of intestinal blood flow allowed calculation of mesenteric vascular resistance and oxygen consumption. Animals underwent stepwise reductions in arterial pressure and acute venous hypertension (10 to 15 mm Hg). There were no differences in baseline hemodynamic or metabolic parameters in control (C) or digitalized (D) animals. Blood flow and oxygen consumption were autoregulated in both C and D rats until perfusion pressure decreased below 50 mm Hg. The response to acute venous hypertension was different. In D rats, venous hypertension resulted in increased vascular resistance (millimeters of mercury per milliliter per minute per 100 gm) [0.89 +/- 0.05 to 0.97 +/- 0.07; p less than 0.05], whereas C rats demonstrated no change [0.92 +/- 0.08 to 0.95 +/- 0.09]. The decrease in oxygen consumption in D rats (-14%) was slightly but significantly greater than that observed in C rats (-9%). Digitalized rats demonstrated a heightened myogenic response to acute venous hypertension with deleterious effects on vascular resistance and oxygen consumption. This reaction was intrinsic to the mesenteric circulation and not mediated by sympathetic nerves or central reflexes. Nonocclusive mesenteric ischemia in digitalized patients may reflect a similar abnormal response to the acute increases in portal pressure accompanying cardiac failure.

Animals↗
PubMed1987

Successful direct extubation of very low birth weight infants from low intermittent mandatory ventilation rate.

It is common practice to use endotracheal continuous positive airway pressure for various time periods up to 24 hours before attempting extubation in infants who are mechanically ventilated. A few studies in newborns have indicated that airway resistance is increased through small endotracheal tubes. This increases the work of breathing and the likelihood of subsequent ventilatory failure. In this study, 27 very low birth weight infants who were 1/2 to 28 days old at the time of extubation were randomly divided into two groups. One group of 13 study infants were extubated directly from intermittent mandatory ventilation rates of six to ten per minute, and the other 14 control infants were placed on continuous positive airway pressure through endotracheal tubes for six hours prior to an attempt to extubate. There was no difference between the two groups in gestational age, postnatal age, weight, or severity of lung disease at the time of extubation. All 13 study infants were successfully extubated without significant apnea or respiratory acidosis. Of the 14 control infants, only seven were successfully extubated; six infants had significant apnea and in one infant respiratory acidosis with pH 7.13 and PCO2 65 developed while receiving continuous positive airway pressure (13/13 v 7/14, P less than .005). The seven infants who failed the preextubation trial of continuous positive airway pressure were later extubated from low intermittent mandatory ventilation rates without significant apnea or respiratory acidosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1983

Effects of hypothalamic stimulation on unit responses recorded from neurons of sensorimotor cortex of awake cats during conditioning.

1. The activity of single units of the coronal pericruciate (CPC) cortex was studied in 11 awake cats during sessions in which a click conditioned stimulus (CS) was repeatedly paired with glabella tap unconditioned stimulus (US) and hypothalamic stimulation (HS). Effects of HS on the activity of cortical units were also studied during sessions in which HS alone was delivered repeatedly every 10 s. 2. HS evoked an increase in spike activity of less than 60 ms latency in 89 of 116 units tested. 3. Repeated presentation of HS that was effective in producing rapid behavioral conditioning resulted in a characteristic reduction in the latency of discharge evoked by HS in cortical units. 4. Short-latency activation (less than 20 ms) of units of the sensorimotor cortex appeared to be characteristic of HS that led to enhanced rates of conditioned response (CR) acquisition. One of the cells responding in this way was identified as a pyramidal cell of layer V by intracellular injection of horseradish peroxidase (HRP). 5. Further analyses of activity were performed on 16 units of the CPC cortex that were followed through conditioning (or reconditioning) and extinction of the CR. After less than 10 CS-US-HS pairings, there was a selective augmentation of unit response to the CS but not of response to an explicitly unpaired discriminative stimulus (DS). Responses to the CS were not similarly augmented when presentations of HS preceded rather than followed the presentations of the CS and US. The rapid development of CS-evoked unit activity coincided with the rapid acquisition of discriminative CRs behaviorally. 6. During conditioning, the most conspicuous increases in CS-evoked unit response occurred at latencies 100 ms or more after onset of the click CS. This corresponded with the behavioral observation that the majority of eye blink CRs occurred with onset latencies longer than 100 ms.

Animals↗
PubMed1975

Prompt regression of cystic vaginal adenosis following cessation of oral contraceptive therapy.

Cystic vaginal adenosis was diagnosed in a 31-year-old woman. This lesion regressed promptly following the cessation of an oral contraceptive (Ovulen-21) which had been used continuously for 5 years. The temporal relationship between discontinuation of contraceptive treatment and the regression strongly suggests that the medication played a causal role in producing cystic vaginal adenosis. A possible mechanism may have been the stimulation of quiescent glands to growth and cystic dilatation, which finally produced a lesion associated with clinical symptoms.

Adult↗
PubMedDate not supplied

Assembly and mixing of two-stage aqueous two-phase protein extractions.

The effect of the order of system assembly was studied in two-stage aqueous two-phase systems loaded with whole bovine blood and BSA. Recovery in the bottom phase of the back extraction varied by up to 40% depending on the manner in which the forward extraction was assembled, significantly impacting upon the efficiency of the process. The effect of mixing intensity was investigated using a simple shear device. As expected, higher shear rates were found to facilitate mass transfer and shorten the time taken to reach equilibrium. Mixing at lower shear rates for extended periods resulted in a lower recovery of protein.

Animals↗
PubMedDate not supplied

Adhesion of percutaneously inserted Silastic central venous lines to the vein wall associated with Malassezia furfur infection.

Percutaneously inserted Silastic central venous catheters have been used for prolonged infusion of parenteral nutrition in neonates. Malassezia furfur infection has been associated with intravenous fat emulsions infused through central venous lines. In this paper, we report two premature infants whose Silastic catheters were adhered to the vein wall with associated M furfur infection.

Abscess↗
PubMedDate not supplied

Sulfamethazine and sulfathiazole determination at residue levels in swine feeds by reverse-phase liquid chromatography with post-column derivatization.

Twenty g sample, to which sulfamerazine has been added as internal standard, is extracted with 0.3N HCl + 1.5% diethylamine in 25% methanol. The sample extract is chilled (to aid clarification), centrifuged, and filtered. The sulfonamides are separated from each other and from co-extracted materials on a C-18 reverse-phase column and detected at 450 nm following post-column derivatization with dimethylaminobenzaldehyde. Two isocratic mobile phases have been tested: (1) acetonitrile-2% acetic acid (17 + 83), with an analysis time of 13 min; and (2) acetonitrile-methanol-2% acetic acid (4 + 16 + 80), with an analysis time of 20 min but an improved analysis for some samples. As many as 40 samples have been analyzed at one time unattended with the aid of an autosampler. A total of about 1500 field samples have been assayed using the method. Method sensitivity is 0.1 ppm for either analyte in a hog finishing fed. Linearity for each of the analytes is satisfactory over a range of 0.4-25 ppm in spiked feeds. Coefficients of variation range from 13% at 0.5 ppm to 2% at 13 ppm as tested over a period of time in naturally contaminated samples. The absolute recovery of sulfamerazine varies with sample matrix, but, in the presence of sulfamerazine as internal standard, recovery has been 96.7-99.7% over the range of 0.1-10 ppm. Sulfamerazine and sulfamoxole were tested for their suitability as internal standards. Sulfamerazine is a good internal standard for sulfamethazine; neither is ideal for sulfathiazole.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMedDate not supplied

Retrospective analysis of risks associated with an umbilical artery catheter system for continuous monitoring of arterial oxygen tension.

We reviewed retrospectively the incidence of complications encountered with two different umbilical artery catheters (UACs): a silicone-rubber end-hole catheter and an electrode-tipped, side-hole catheter for continuous, invasive monitoring of arterial oxygen tension (PaO2). During calendar year 1989, there were 457 admissions to the neonatal intensive care unit: 168 patients had placement of a UAC. Two of these were admitted only briefly for cardiac catheterization and were eliminated from analysis. One patient had both types of catheters placed sequentially. Thus the data on 166 patients with 51 PaO2 monitors and 116 silicone-rubber UACs were evaluated. The patients who had a PaO2 monitor UAC had a lower mean birth weight than those in the other group (1621 +/- 1043 gm vs 1972 +/- 1048 gm; p = 0.0473). The catheter life span was not different between the groups, with a range of 1 to 16 days for PaO2 monitors and 1 to 27 days for silicone-rubber UACs. Inability to withdraw blood, poor blood pressure tracing, or both conditions resulted in catheter removal for 5 of 51 PaO2 monitor UACs and 4 of 116 end-hole UACs. The incidence of these problems did not differ significantly between the two groups. There were no cases of thromboembolic complications in the patients who had a PaO2 monitor UAC, whereas two of the silicone-rubber UACs were removed because of perfusion problems in the lower limbs, which resolved with decannulation. We conclude that the use of the PaO2 monitor UAC allows for continuous, invasive monitoring of PaO2 without any significant increase in risk compared with that for the silicone-rubber end-hole UAC.

Catheterization, Peripheral↗
PubMedDate not supplied

Experience with double-lumen umbilical venous catheters in the low-birth-weight neonate.

Reliable vascular access can be problematic in sick low-birth-weight neonates. Umbilical venous catheters are one form of vascular access that can be used in this population. A retrospective review of experience with umbilical venous catheters in our neonatal intensive care unit from January 1989 through December 1991 was conducted. This included 128 patients: 70 with single-lumen (Gesco Umbilicath II) and 58 with double-lumen (Becton-Dickinson Careflow) catheters. Birth weight, gestational age, catheter life span, complications, and number of punctures for peripheral intravenous lines were analyzed. The mean birth weight, gestational age, and catheter life span did not differ significantly between catheter types. The incidence of catheter-related sepsis did not differ significantly (two single-lumen, three double-lumen) and occurred only in neonates with a catheter life span greater than 10 days. The number of intravenous punctures was significantly decreased in those neonates with double-lumen umbilical venous catheters (p < 0.0001). We conclude that in sick low-birth-weight infants the use of double-lumen umbilical venous catheters entails no greater risk than the use of a single-lumen umbilical venous catheter and may reduce iatrogenic stress associated with the starting of peripheral intravenous lines.

Catheterization, Peripheral↗