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Biomedical subjects

G Lee

Publications and source records attributed to G Lee.

At least 361 records · Page 20Linked to original sources
PubMed1986

Comparison of intravenous mexiletine and lidocaine for the treatment of ventricular arrhythmias.

The efficacy and safety of intravenous loading of mexiletine was compared to lidocaine in patients with ventricular premature depolarizations (VPDs). Seventeen men and five women, average age 63 years, completed this randomized parallel study. Twelve patients received mexiletine intravenously at (5 to 10 mg/min) until greater than or equal to 95% VPD suppression was achieved or a total of 450 mg of drug was given. The average loading dose of mexiletine was 4.4 mg/kg, at an infusion rate of 0.1 mg/kg/min. Ten patients received lidocaine (1 mg/kg) given over 3 minutes, with a second similar bolus given if after 10 minutes greater than or equal to 95% VPD suppression was not achieved. Total VPDs were determined for the 60 minutes before drug administration, during drug infusion, and 60 minutes thereafter. Eleven of 12 (92%) patients receiving mexiletine were full responders (greater than or equal to 95% suppression) and one was a partial responder (greater than or equal to 75% greater than or equal to 95% suppression). Five of 10 lidocaine patients (50%) were full responders, three (30%) were partial responders, and two failed to respond. At peak suppression, mexiletine reduced mean VPD from 37 +/- 33/5 minutes (mean +/- S.D.) to 0.8 +/- 0.9/5 minutes (p less than 0.01) and lidocaine decreased mean VPDs from 28 +/- 47/5 minutes to 4.7 +/- 2.2/5 minutes (p less than 0.01). Mexiletine resulted in greater suppression of VPDs than lidocaine in terms of mean percent reduction (96% vs 68%, p less than 0.01). All lidocaine patients had therapeutic plasma levels (range 1.6 to 3.5 micrograms/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Conjunctival oxygen tension monitoring during helicopter transport of critically ill patients.

To investigate the utility of conjunctival oxygen tension measurement during helicopter transport, we monitored conjunctival oxygen tension (PcjO2) in 36 clinically unstable patients. Sixteen (44%) of the patients were found to have ventilatory or circulatory compromise as determined by PcjO2 less than 50 torr. In only three of these patients would vital sign determinations have detected the unstable clinical states. In 12 patients (33%), respiratory intervention or expansion of intravascular volume resulted in improvement of tissue oxygenation and clinical state. These results demonstrate that a substantial fraction of our patients transported by helicopter had underlying physiologic abnormalities that were not apparent by monitoring of vital signs, but were detected and corrected by measurement of conjunctival oxygen tension.

Adolescent↗
PubMed1986

Allogeneic hepatocyte transplantation in the rat spleen under cyclosporine immunosuppression.

An innovative approach for stimulating the rapid growth of allogeneic hepatocytes implanted into splenic tissue with maintenance of the structural integrity is described. Single cell suspensions of hepatocytes from normal male ACI-strain rats (RTIa) were injected (2 X 10(6) cells) into the spleen of allogeneic male Fischer (RTI1) recipient rats. A 70% partial hepatectomy (PH) was performed at the same time as hepatocyte transplantation. Animals were treated for 4 days prior to, and 1 day after, transplantation with a feeding regimen containing 0.05% 2-acetylaminofluorene (AAF) to inhibit regeneration of the residual host liver. Animals received cyclosporine (CsA) 3 mg/kg/day s.c. posttransplantation. Histological examination of a standard longitudinal section of the recipient spleen two days posttransplant revealed an approximately 0.54-mm2 area replaced by hepatocytes. By 7 days this had increased to 0.97 +/- .15 mm2. Without CsA administration, hepatocytes were undetected at 7 days. Both PH and AAF treatment were necessary for successful colonization and sustained proliferation. Withdrawal of CsA treatment at 10 days after transplantation resulted in rapid rejection of established hepatocytes. This study demonstrates that rapid colonization of the rat spleen with allogeneic hepatocytes can be achieved, and that the viability and structural integrity of these transplanted cells can be maintained for at least 14 days using cyclosporine immunosuppression.

2-Acetylaminofluorene↗
PubMed1986

Effects of physical restraint on leukemogenesis by Friend virus.

The effects of physical restraint on the development of Friend erythroleukemia in ddY mice were examined. Restraint was applied by immobilizing the mice in wire cages. In both sexes there was a reduction in the weight of the whole body, thymus and spleen, though the food intake was not reduced. The incidence of leukemia was reduced in the males, but not in the females, while the latent period was prolonged in both sexes. This sex dependency is characteristic of the stress response.

Animals↗
PubMed1986

Stability of ganciclovir sodium (DHPG sodium) in 5% dextrose or 0.9% sodium chloride injections.

The stability of 9-[(1,3-dihydroxy-2-propoxymethyl]) guanine sodium (ganciclovir sodium, also known as DHPG sodium) in two infusion solutions was studied. Lyophilized ganciclovir sodium 500 mg was reconstituted with sterile water 10 mL to give a theoretical concentration of 50 mg/mL. After reconstitution, 6-mL aliquots of the solution were added to 100 mL of 0.9% sodium chloride injection or 5% dextrose injection in polyvinyl chloride i.v. bags. One sample was withdrawn from each of 10 bags of each solution and analyzed by high-performance liquid chromatography (HPLC). Thirty bags of each solution were then stored under each of the following conditions: at room temperature under laboratory light, at room temperature in the dark, and under refrigeration for up to five days. Single potency assays were performed by HPLC on each of three bags of solution at three and five days after initial dilution of the solutions. The solutions were visually inspected, and the pH of the solutions was measured. All solutions of ganciclovir were stable for at least five days under all storage conditions; mean ganciclovir concentrations did not drop below 98% of initial theoretical values throughout the storage period. No important changes in the pH of the solutions occurred during the study period. Under the conditions of this study, ganciclovir sodium is stable for up to five days when prepared in 5% dextrose injection or 0.9% sodium chloride injection.

Acyclovir↗
PubMed1986

Transport of the critically ill trauma patient.

Nurses play an important role in the transport of critically ill trauma patients. The special problems one encounters in ground and/or air transfers must be anticipated. The patient should be prepared both physically and emotionally for this process, and all nurses involved in the transport should work together to insure positive patient outcome.

Adult↗
PubMed1985

Argon laser radiation of human clots: differential photoabsorption in red cell rich and red cell poor clots.

Since argon laser radiation (454-514 nm) can vaporize human clots, we determined whether the absorption of laser energies can differ among different types of blood clots. Thus we performed spectrophotometric studies and examined the ability of this laser to penetrate red cell rich and red cell poor clots. Fifty-four red cell rich and red cell poor clot samples, varying in depth from 1.8 to 5.0 mm, were subjected to 3, 5 and 7 watts from an argon laser beam. At a given power intensity, the deeper the red cell rich clot, the longer was the time needed to penetrate the clot. The higher the power used, the shorter was the red clot penetration time. In contrast, all power levels used up to 5 minutes did not penetrate any of the varying depths of red cell poor clots. Spectrophotometrically, the red cell rich clot had an absorption curve typical of hemoglobin pigment while the red cell poor clot, in the absence of hemoglobin, had poor absorption between 350 and 600 nm and was unable to absorb argon laser energies. Thus, the argon laser provides a therapeutic modality for human red cell rich clot dissolution but the present approach does not appear to be effective against red cell poor clots.

Blood Coagulation↗
PubMed1985

In vitro fertilization and embryo transfer: an individualized approach to ovulation induction.

Because of the inherent marked individual responsiveness to ovulatory stimulating agents, a highly individualized approach to ovulation induction for in vitro fertilization has been utilized. The starting time for medication was varied according to the previous mean cycle length. The dose of clomiphene citrate was adjusted to the body weight. The dose and duration of both clomiphene and human menopausal gonadotropin (hMG) were adjusted as early as treatment day 5 in accordance with the ultrasonic findings. The day of human chorionic gonadotropin (hCG) administration was varied according to a combination of ultrasonic findings and plasma estradiol levels. This approach resulted in a mean retrieval of four oocytes per laparoscopy, 75% of which were mature, a fertilization rate of 78%, and a pregnancy rate of 14% of laparoscopies.

Adult↗
PubMed1985

Applicability of laser to assist coronary balloon angioplasty.

Severe atherosclerotic obstructed coronary artery disease (CAD) may preclude passage of a balloon catheter for transluminal coronary angioplasty (TCA). Since lasers have been shown to effectively vaporize CAD plaque, the initial application of laser to effect a lumen large enough to accommodate the angioplasty catheter for further dilatation was explored. Eleven postmortem human CAD segments which did not permit passage of a 1.33 mm shaft diameter angioplasty catheter were studied. Argon laser radiation (14 to 90 J) transmitted via 400 micron core diameter quartz fiber onto the stenotic channel of 0.58 mm created a vaporized lumen of 1.77 mm (mean increase of 1.31 +/- 0.25 mm, p less than 0.001). The laser procedure allowed the balloon angioplasty catheter to be pushed into the stenosis. TCA was then performed (7 atm, 45 seconds) and expanded the channel to 2.12 mm (additional mean increase of 0.38 +/- 0.07 mm, p less than 0.001). In terms of percent luminal narrowing, laser radiation reduced obstruction from 80% to 45% (mean difference of -38.7 +/- 4.6%, p less than 0.001), and TCA caused a further decrease to 37% (mean difference of -9.3 +/- 1.9%, p less than 0.001). Thus, in tight atherosclerotic lesions, the laser may be useful in creating an initial opening enabling the placement of the balloon angioplasty catheter which, in turn, can further dilate the lased stenotic coronary lumen.

Angioplasty, Balloon↗
PubMed1985

Gastrointestinal hemorrhage due to Mallory-Weiss syndrome in an infant.

A Mallory-Weiss tear of the gastroesophageal mucosa is reported as an unusual cause of upper gastrointestinal bleeding in a 3-week-old infant. The lesion, documented by endoscopy, appeared to follow hiccups. The bleeding responded to conservative medical management and resolved without surgical intervention.

Endoscopy↗
PubMed1985

AIDS surveillance in haemophilia.

We suspected a patient attending our Haemophilia Centre had developed Acquired Immunodeficiency Syndrome (AIDS) and therefore immunological evaluation was performed on 43 patients with haemophilia and von Willebrand's disease attending the Centre. The index patient died of Pneumocytis carinii pneumonia. Thirty-one patients had either abnormal T cell subsets or helper/suppressor ratios. Thirty-two patients had hypergammaglobulinaemia. There was no direct correlation between these immunological abnormalities and the total amount or type of treatment received. T cell abnormalities were not confined to the 13 patients who had received the same batches of concentrate as the index case. The index case simultaneously contracted hepatitis B. He was the only patient to receive a large amount of the suspect batches of concentrate, not previously immune to hepatitis B.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Natriuretic and smooth muscle responses to human urinary natriuretic hormone in rats: relation to blood pressure and kallikrein excretion in patients.

Human urine contains a small molecular weight natriuretic substance and similar material isolated from the kidney inhibits Na/K ATPase. Such action on smooth muscle in blood vessels would cause contraction. Human urinary natriuretic material caused contraction of the smooth muscle in the rat anococcygeus muscle and this activity correlated with its natriuretic activity. Known vasoactive substances could not explain the activity of the natriuretic factor when tested on the anococcygeus muscle. The best correlation with blood pressure of the patient was with the log of the ratio of natriuretic activity divided by the kallikrein excretion. A normotensive woman with severe renal failure had very high kallikrein excretion as well as increased natriuretic activity and her data fitted the same correlation as the hypertensives' data.

Animals↗