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Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 955 records · Page 53Linked to original sources
PubMed1986

Coronary angioscopy in patients with unstable angina pectoris.

To visualize intracoronary lesions in patients with different clinical expressions of coronary disease, we performed coronary angioscopy during coronary-artery bypass surgery in 10 patients with unstable angina and 10 patients with stable coronary disease. We examined a total of 32 vessels, using flexible fiberoptic angioscopes. Twenty-two vessels had no acute intimal lesion; three had complex plaques, six had thrombi, and one had both. Coronary angiography correctly identified the absence of complex plaque and thrombus in 22 vessels, but it detected only one of four complex plaques and one of seven thrombi. On angioscopy, none of the 17 arteries in the patients with stable coronary disease had either a complex plaque or thrombus. In the "offending" arteries of the patients with unstable angina, all three patients with accelerated angina had complex plaques and all seven with angina at rest had thrombi. We conclude that angioscopy frequently reveals complex plaques or thrombi not detected by coronary angiography. Our observations suggest that anginal syndromes that are refractory to medical treatment can be caused by unstable pathologic processes in the intima. Ulceration of plaques may increase the frequency and severity of effort angina, and the subsequent development of partially occlusive thrombi may cause unstable rest angina.

Adult↗
PubMed1986

Occurrence of aromatic L-amino acid decarboxylase in human plasma and its assay by high-performance liquid chromatography with fluorescence detection.

A high-performance liquid chromatographic method using fluorescence detection for assessing the activity of aromatic L-amino acid decarboxylase in human plasma is described. Dopamine, formed enzymatically from L-DOPA, and isoproterenol (internal standard) are chromatographed on a small ion-exchange cartridge (Toyopak SP) and derivatized with 1,2-diphenylethylenediamine. The derivatives are separated by reversed-phase chromatography on an Ultrasphere ODS column. The detection limit for dopamine formed enzymatically is 0.6 pmol per 500 microliter of enzyme reaction mixture. Aromatic L-amino acid decarboxylase in human plasma is very similar to that in rat kidney, with respect to optimum conditions for the enzyme reaction and gel chromatographic behaviour.

Adult↗
PubMed1986

Spontaneous regional lymph node metastases of three variants of the B16 melanoma: relationship to primary tumor size and pulmonary metastases.

We studied the patterns of spontaneous regional lymph node metastases of three variants (F1, F10, and BL6) of the B16 melanoma in C57BL/6 mice and related the incidence to primary tumor size and pulmonary metastases. The incidence of regional lymph node and pulmonary metastases correlated with increasing primary tumor size (p less than or equal to 0.0001). The incidence of pulmonary metastases in mice whose regional lymph nodes did not contain tumor also correlated with increasing primary tumor size (p less than or equal to 0.0001). This propensity for direct hematogenous spread was more apparent in BL6 tumors than in F1 and F10 tumors (p less than or equal to 0.0001). BL6 tumors also metastasized to regional nodes at smaller primary tumor sizes (p less than or equal to 0.04). Heterogeneous variants that metastasize earlier to regional lymphatic and hematogenous sites dictates the natural history of the primary tumor. Whether prophylactic lymphadenectomy for melanomas is therapeutic may depend on dissemination-related phenotypic characteristics.

Animals↗
PubMed1986

Enhancement of cerebellar Purkinje cell complex discharge activity by microiontophoretic serotonin.

The major finding of the present study is that iontophoretically applied serotonin increased markedly (average 94.0%) the number of complex discharges within the majority (74%) of cerebellar Purkinje cells tested. Twenty-five percent of the cells showed an average 23% decrease in complex discharges, whereas 1% of the cells failed to respond. The effects of serotonin on complex activity were not related to any single effect of this amine on simple spike activity. It was apparent that the actions of serotonin on complex discharge activity were correlated with the initial simple-spike firing rate of the Purkinje cell and the predrug number of complex discharges. The other component of the complex discharge pattern analyzed in this study was the mean post-complex-discharge interval (MPCI). Purkinje cells evincing lower MPCI values were those in which serotonin increased the MPCI value preferentially, whereas cells in which serotonin depressed MPCI values exhibited higher predrug MPCI values. The serotonin antagonists methysergide and metergoline antagonized serotonin-induced enhancements in the numbers of complex discharges, whereas ketanserin failed to alter the response, suggesting a degree of receptor specificity. Comparisons between the present study and our previous work identifying a rate-dependent component to the actions of serotonin on simple spike activity are described.

Animals↗
PubMed1986

Pulmonary Kaposi's sarcoma in the acquired immune deficiency syndrome. Clinical, radiographic, and pathologic manifestations.

Pulmonary Kaposi's sarcoma related to the acquired immune deficiency syndrome (AIDS) has not been well characterized. To define the clinical, radiographic, and pathologic features of this entity, 11 autopsy-proved cases of pulmonary Kaposi's sarcoma were reviewed. The most common clinical symptoms were dyspnea and cough, but hemoptysis and stridor were also found. Nodular infiltrates and pleural effusions were the most commonly found radiographic abnormalities. Pulmonary function tests were sensitive in detecting the pulmonary abnormalities due to Kaposi's sarcoma. A low diffusion capacity, lack of arterial desaturation with exercise, and obstruction to airflow were suggestive of pulmonary involvement with this malignancy. Although endobronchial Kaposi's sarcoma was visualized at bronchoscopy as cherry-red, slightly raised lesions, bronchial biopsy specimens always showed no abnormalities. Transbronchial brushings and biopsy specimens and analysis of pleural fluid were also not helpful in establishing a diagnosis. In the seven subjects with extensive parenchymal Kaposi's sarcoma at autopsy, the pleura was always involved. Eight subjects had involvement of the tracheobronchial tree. In all of the subjects, pulmonary Kaposi's sarcoma was a significant cause of morbidity, and in three of 11 subjects (27 percent) it was the direct cause of death.

Acquired Immunodeficiency Syndrome↗
PubMed1986

The primary role of the Erb's point--axilla segment in median and ulnar motor nerve conduction determinations in alcoholic neuropathy.

Motor nerve conduction velocity (MNCV) was explored in the Erb's point-axilla (N-A) nerve segment of median and ulnar nerves, bilaterally, in 10 patients with a history of prolonged heavy drinking but in whom no other predisposing factors to peripheral neuropathy were found. For comparison, MNCV was determined also in the axilla-elbow (A-E), elbow-wrist (E-W) nerve segments, as well as the motor terminal latency (MTL) of the same nerves. A total of 140 nerve segments were tested tested but only 133 results were obtained. Abnormal MNCV or MTL was found in 36 or 27% of all tested nerve segments. From the latter, 38.9% were in the N-A nerve segments. Of N-A nerve segments tested, reduction in MNCV was found in 46.7%. Our results are statistically significant.

Adult↗
PubMed1986

Safety and efficacy of intravesical aminocaproic acid for bleeding after transurethral resection of prostate.

There appears to be no clinically significant difference in blood loss or transfusion requirements after transurethral resection of the prostate (TURP) when intravesical 0.5% aminocaproic acid is compared with 0.9% sodium chloride irrigation in patients during the first three days after surgery. This is probably because early post-TURP bleeding is due to inadequate hemostasis or perforation of the prostatic capsule, and not excessive local or systemic fibrinolysis. However, we suggest that intravesical aminocaproic acid might be a useful alternative to systemic antifibrinolytic therapy in patients with delayed, recurrent, excessive post-prostatectomy bleeding, which is thought to be due to fibrinolysis. Since aminocaproic acid is not systemically absorbed after bladder instillation, intravesical administration causes few side effects and does not necessitate screening patients for disseminated intravascular coagulation prior to treatment.

Aged↗
PubMed1986

Is the refractometer specific gravity a reliable index for pediatric fluid management?

Serial measurement of urinary output has been one of the mainstays to gauge adequacy of hydration of the newborn surgical patient. Urine output, however, is dependent not only on circulating blood volume but also on osmolar load and the ability of the kidney to excrete solute and water. Therefore, a second measurement is necessary for more accurate monitoring urine concentration. The purpose of this study is to determine the capacity of the kidneys of the newborn surgical patient to dilute and concentrate, and to excrete solute and water; and the accuracy of the refractometer to determine the tonicity of urine. To determine renal capacity, 24 newborn patients were studied during the first 48 hours following major surgical procedures. Analysis of 823 urine samples demonstrated a range of specific gravity between 1.002 and 1.040, and of osmolality between 67 and 582 mosm/kg. The lowest urine output was 0.1 mL/kg/hr and the highest 14.9 mL/kg/hr (mean 3.54 +/- 1.97 mL/kg/hr). The osmolar load excreted by the kidney ranged from 3.7 to 33.4 mosm/kg/24 hr (15.3 +/- 6 mosm/kg/24 hr). To determine the accuracy of the refractometer, 2,007 urine samples from 900 newborn infants were studied. The correlation coefficient for refractometer derived specific gravity and osmolality ranged from 0.7347 to 0.9061. Refractometer specific gravity measurements of 1.008 or below predict hyposmolality as defined as an osmolality below 270 mosm/kg with an accuracy of 70.6% to 95.4%. Accuracy is significantly less in the TPN and the glucose groups. A specific gravity of 1.012 to 1.020 is accurate in predicting hyperosmolality as defined as a urine osmolality above 290 mosm/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Diuresis↗
PubMed1986

Hemorrhagic complications of piperacillin therapy.

Clinically significant hemorrhage associated with extended spectrum anti-Pseudomonas penicillins is uncommon. We describe 2 patients with bleeding complications owing to piperacillin. In addition, we review the incidence and mechanism of this adverse reaction, and make suggestions for the management of these patients.

Blood Coagulation Tests↗
PubMed1986

Lymphocele formation after extraperitoneal pelvic lymphadenectomy: possible predisposing factors.

A retrospective review of 61 patients undergoing pelvic lymphadenectomy was performed to assess possible predisposing factors for lymphocele development. The procedure was done to facilitate staging of prostatic carcinoma in all of the patients. The complication occurred in 9 patients (14.8 per cent). Analysis revealed a statistically significantly higher incidence of lymphoceles in patients without drainage (p less than 0.05) and in patients whose lymph nodes had no metastatic disease (p less than 0.025). Furthermore, 9 patients (without drainage and with nodes that were free of tumor but who received mini-dose heparin therapy) as a subgroup had the highest incidence of lymphocele formation. Although these individual factors have been attributed to this complication after lymphadenectomy they may act synergistically.

Adenocarcinoma↗
PubMed1986

Pituitary and thyroid hormones in pregnant alcohol-fed rats and their fetuses.

The effect of maternal alcohol consumption on serum and pituitary concentrations of hormones was investigated in pregnant rats and their fetuses. Rats were given 20% ethanol in water prior to pregnancy and 30% ethanol in water throughout gestation, with rat chow ad libitum (alcohol group), or water with an equicaloric diet in which corn starch was substituted for alcohol (pair-fed group), or rat chow and water ad libitum (ad libitum control group). Growth hormone (GH), prolactin (Prl), thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) were measured in maternal serum, GH, Prl, and TSH in maternal pituitary, and GH, T4, and T3 in fetal serum. Fetuses of alcohol-fed rats weighed significantly less than fetuses of pair-fed or ad libitum controls. GH, Prl, and TSH were significantly reduced in the maternal serum of alcohol and pair-fed rats compared to ad libitum controls, but T4 and T3 did not differ among the three groups. Pituitary GH was reduced in the alcohol-fed rats, but pituitary Prl and TSH did not differ among the three groups. In the fetuses, neither GH nor T4 differed among the three groups. Fetal T3 was not detectable by this assay. It is suggested that alcohol ingestion affects maternal growth hormone levels, possibly by influencing either the synthesis or the release of the hormone from the pituitary gland. The other hormonal changes may be the result of the reduced food intake, rather than a specific effect of alcohol.

Alcoholism↗
PubMed1986

Conserved regions in defective interfering viral double-stranded RNAs from a yeast virus.

We have completely sequenced a defective interfering viral double-stranded RNA (dsRNA) from the Saccharomyces cerevisiae virus. This RNA (S14) is a simple internal deletion of its parental dsRNA, M1, of 1.9 kilobases. The 5' 964 bases of the M1 plus strand encode the type 1 killer toxin of the yeast. S14 is 793 base pairs (bp) long, with 253 bp from the 5' region of its parental plus strand and 540 bp from the 3' region. All three defective interfering RNAs derived from M1 that have been characterized so far preserve a large 3' region, which includes five repeats of a rotationally symmetrical 11-bp consensus sequence. This 11-bp sequence is not present in the 5' 1 kilobase of the parental RNA or in any of the sequenced regions of unrelated yeast viral dsRNAs, but it is present in the 3' region of the plus strand of another yeast viral dsRNA, M2, that encodes the type 2 killer toxin. The 3' region of 550 bases of the M1 plus strand, previously only partially sequenced, reveals no large open reading frames. Hence only about half of M1 appears to have a coding function.

Base Sequence↗
PubMed1986

Association of pheochromocytoma with nephrocarcinoma. Case report and literature review.

We describe an unusual case of an elderly male with mild hypertension, who underwent a right radical nephrectomy for a nephrocarcinoma and developed accelerated hypertension intraoperatively. Postoperative pathology of the excised specimen revealed poorly differentiated nephrocarcinoma and pheochromocytoma of the right adrenal gland. The limited published literature on the association of nephrocarcinoma and pheochromocytoma is reviewed, and suggestions for optimal preoperative evaluation of these patients are offered.

Adrenal Gland Neoplasms↗
PubMed1986

Pulmonary tuberculosis and bronchocentric granulomatosis.

Bronchocentric granulomatosis (BG) is an uncommon inflammatory lesion of unknown etiology defined on morphologic grounds by the presence of necrotizing granulomata centered on bronchi and bronchioles. We report the typical pathologic features of BG in a patient with tuberculosis. Mycobacterial and other types of infection should be excluded by appropriate stains and cultures in all patients with BG on lung biopsy, especially those who are nonasthmatic.

Adult↗
PubMed1986

Teaching social language to moderately handicapped students.

Three students with moderate handicaps were taught to initiate and expand on conversational topics. The teaching procedure used stimuli generated from actual conversations with nonhandicapped peers. Generalization was assessed by audiotaping conversations between the handicapped students and their peers in natural school contexts without adult supervision. Results indicated that training generalized to natural contexts. These results were socially validated by undergraduate special education students, who rated tapes of two of the students' conversations during training phases as more socially competent than during baseline. Results are discussed in terms of the evaluation of complex social behavior as multioperant behaviors.

Adolescent↗