123rc/medical_text huggingface dataset:
Application of a modified bioassay for monitoring serum teicoplanin and vancomycin in febrile neutropenic patients. Teicoplanin is a glycopeptide antibiotic with a mode of action and spectrum of activity similar to those of vancomycin. Its efficacy and tolerability as empiric therapy and its pharmacokinetic properties in neutropenic patients are being studied in a double-blinded, randomized trial in comparison with those of vancomycin. We report here a modified agar diffusion bioassay which is suitable for monitoring levels of either teicoplanin or vancomycin in serum during combination therapy with beta-lactams, aminoglycosides, and amphotericin B. Serum samples spiked with either teicoplanin or vancomycin gave reproducible results (mean coefficient of variation, 8.8%) regardless of the presence of tobramycin, amikacin, piperacillin, ceftazidime, amphotericin B, or their combinations. Among 25 patients who received teicoplanin at a dosing schedule of 6 mg/kg every 24 h intravenously, steady state was reached after 14.2 +/- 4.0 days, and 1-h peak and trough concentrations of teicoplanin in serum at steady state were 40.8 +/- 15.0 and 12.5 +/- 3.2 mg/liter, respectively. In contrast, among 25 patients who received vancomycin at a dosing schedule of 15 mg/kg every 12 h intravenously, steady state was reached by 24 h, and the 1-h peak and trough concentrations in serum were 37.5 +/- 15.6 and 8.3 +/- 3.8 mg/liter, respectively. The elimination half-lives for teicoplanin estimated by two separate approaches agreed closely with each other: 80.5 +/- 21.5 h by an accumulation model (M. Gilbaldi and D. Perrier, Pharmacokinetics, 2nd ed., p. 121, 1982) and 87.3 +/- 19.3 h as predicted from the degree of renal function (M. Rowland, Clin. Pharmacokinetic 18:184-209, 1990). These values were 14- to 15-fold higher than that for vancomycin (5.6 +/- 1.8 h).
A clinicopathologic study of the eyes in familial adenomatous polyposis with extracolonic manifestations (Gardner's syndrome). The eyes of a 51-year-old woman with familial adenomatous polyposis and extracolonic manifestations (Gardner's syndrome) were obtained postmortem and studied by light microscopy and by transmission and scanning electron microscopy. We found a generalized abnormality in melanogenesis of the retinal pigment epithelium and at least three types of pigmented lesions. The histologic findings in one type of lesion were consistent with congenital hypertrophy of the retinal pigment epithelium or benign pigmented nevus of the retinal pigment epithelium. The other two types of lesion were most consistent with hamartomatous malformations of the retinal pigment epithelium featuring cellular hypertrophy, hyperplasia, and rarely retinal invasion and formation of a minute mushroom-shaped tumor. These histopathologic findings indicate a generalized effect of the familial adenomatous polyposis gene on the retinal pigment epithelium. This oncogene, which is responsible for tumor formation in the gastrointestinal tract, soft tissues, bone, and other locations in patients with familial adenomatous polyposis, also leads to a generalized defect in melanogenesis and focal lesions of the retinal pigment epithelium.
Transfection and stable transformation of adult mouse Schwann cells with SV-40 large T antigen gene. Cultured Schwann cells derived from adult mouse dorsal root ganglia and peripheral nerves were transfected with a plasmid containing SV-40 large T antigen gene, and 25 colonies of stable transformants were obtained, one of which was expanded and recloned. This transfected cell line, designated MS1, expressed SV-40 large T antigen and showed continuous cell growth with a doubling time of 27 hours. The MS1 cells had distinct Schwann cell phenotypes such as S-100 protein, laminin, 2',3'-cyclic nucleotide 3'-phosphodiesterase and P0 protein, as shown by immunofluorescence microscopy. When MS1 cells were exposed to dibutyryl cyclic adenosine-3',5'-monophosphate (dbc AMP), they extended long bipolar processes two- to ten-fold longer than those of untreated MS1 cells and frequently formed whorl-like alignments similar to palisade formations or organoid patterns observed in human Schwannomas and neurofibromas. These results suggest that transformed Schwann cells can be a useful model for analyzing regulatory mechanisms of Schwann cells, neuron-Schwann cell interactions and experimental Schwann cell neoplasms in vitro.
Kaposi's sarcoma involvement of the bone marrow. Kaposi's sarcoma (KS) is a predominantly cutaneous malignancy with several clinical variants. Extracutaneous sites of involvement are uncommon in all disease variants except epidemic KS (human immunodeficiency virus related) and the African lymphadenopathic variant. Extracutaneous KS usually involves the lymph nodes, gastrointestinal tract, and respiratory tract. The authors report the first description of a patient with classic KS to have bone marrow involvement. Two additional patients with KS variants and bone marrow involvement have been described. Bone marrow tumor invasion should be considered in patients with KS and hematologic abnormalities.
Electrophysiologic effects of exogenous phosphocreatine in cardiac tissue: potential antiarrhythmic actions. The cellular electrophysiologic effects of exogenous phosphocreatine (PCr) were analyzed to ascertain its purported antiarrhythmic properties during myocardial ischemia and reperfusion. Transmembrane potentials were recorded from isolated guinea pig papillary muscles and Purkinje fibers studied in vitro. Under control, normoxic conditions, 10 mmol/L PCr significantly increased the action potential duration (measured at 90% of repolarization) in ventricular muscle by 14.6 +/- 3.3 msec and the effective refractory period by 11.5 +/- 3.8 msec (both p less than 0.01). Under ischemic-like conditions (hypoxia, lactic acidosis, elevated [K+]o, zero substrate) PCr had no effect. Phosphocreatinine, a related compound that is not a direct substrate in the creatine kinase reaction, acted similarly to PCr suggesting that alterations induced by PCr did not involve a change in the energy state of cells. However, PCr reduced free [Ca2+]o by nearly 20%, and its electrical effects under normoxic conditions could be largely reversed by a concomitant 20% increase in [Ca2+]o. In Purkinje fibers superfused with low [K+]o-Tyrode's solution to elicit conditions of Ca2+ overload, delayed afterdepolarizations and triggered responses were reversibly inhibited by PCr. These data suggest that the antiarrhythmic effects of PCr in situ may involve prolongation of the effective refractory period in nonischemic tissue or attenuation of membrane changes elicited by Ca2+ overload in ischemic cells. The mechanism by which PCr produces these effects may be related in part to changes in extracellular Ca2+ composition.
Resolution of cirrhotic glomerulonephritis following successful liver transplantation. A 38-year-old man with liver failure due to Laennec's cirrhosis developed nephrotic range proteinuria and hematuria. Renal biopsy showed membranoproliferative glomerulonephritis with 2+ staining for IgA and complement consistent with cirrhotic glomerulonephritis. After orthotopic liver transplantation, proteinuria and hematuria rapidly resolved. This case indicates that glomerulonephritis associated with cirrhosis may be successfully treated with hepatic transplantation. Whether the improvement in glomerular abnormalities resulted from immunosuppression therapy or from restoration of normal hepatic function is unknown.
Usefulness of pulsed Doppler ultrasound in detection of angiographically evident recurrence of hepatocellular carcinoma after arterial embolization treatment. Because hepatocellular carcinoma treated by transcatheter arterial embolization often regains its size, routine follow-up is necessary. The usefulness of pulsed Doppler ultrasound for detection of this type of recurrence was compared with ultrasonography and computed tomography in 21 such hepatocellular carcinomas. Of 15 hepatocellular carcinomas diagnosed by angiography as showing recurrence, four were detected with ultrasonography and five were detected with computed tomography. Doppler signals were obtained in the peripheral portions corresponding to tumor vessels or stains on angiograms in 14 of these 15 hepatocellular carcinomas, but they were undetectable in six hepatocellular carcinomas with no recurrence. All signals disappeared after transcatheter arterial embolization. One false-negative hepatocellular carcinoma with pulsed Doppler ultrasound showed faint tumor stains on angiograms; these were also negative on ultrasonography and computed tomography. Pulsed Doppler ultrasound may be superior to ultrasonography and computed tomography as a routine procedure to detect the recurrence of hepatocellular carcinoma treated by transcatheter arterial embolization.
Ultrasonic evaluation of early carotid atherosclerosis. We investigated the prevalence of carotid atherosclerosis, including mild early lesions, and its association with cervical bruits and various risk factors (age, male sex, hypertension, hyperlipidemia, diabetes mellitus, obesity, and cigarette smoking) in 232 consecutive Japanese patients. High-resolution real-time B-mode ultrasonography was performed to determine the extent of atherosclerosis, and it was quantified by using a scoring system. The prevalence of carotid atherosclerosis was 49%, 59%, and 41% in all 232 patients, the 100 symptomatic patients, and the 132 asymptomatic patients, respectively. Although carotid lesions were detected frequently (87%) in the 30 patients with cervical bruits, bruits were noted in only 30% of the 88 examined patients with carotid atherosclerosis. Independent risk factors for carotid atherosclerosis in these patients were found to be age, male sex, and hyperlipidemia; diabetes mellitus was a possible risk factor for carotid atherosclerosis. Our study did not show a close association between hypertension and carotid atherosclerosis, and this might be caused by the high prevalence of hypertension in our patients. Our findings suggest an increasing prevalence of carotid atherosclerosis in the Japanese, though this should be confirmed in a population-based study. Our study demonstrates the clinical usefulness of high-resolution B-mode ultrasonography for the evaluation of early carotid atherosclerosis.
The Maylard incision in gynecologic surgery The transverse muscle-splitting Maylard incision was used in 175 gynecologic patients who required pelvic-abdominal surgery. One hundred fifty-three patients (87%) had pelvic malignancy; other indications for operation included uterine myomas, endometriosis, tuboovarian abscess, and benign ovarian cysts. Exposure was excellent: 54% of patients underwent pelvic lymphadenectomy and 17% underwent paraaortic lymphadenectomy. Twelve patients (6.9%) had wound complications, but there was neither long-term morbidity nor mortality associated with the incision. Fifty-six patients (32%) received preoperative or postoperative pelvic radiation therapy with no detrimental effect on wound healing. The Maylard incision is cosmetic, strong, easily learned, and has an acceptable complication rate. Unless a vertical incision is indicated, the Maylard technique is preferred when optimal exposure and accessibility to the pelvis are required.
Apical segmental dysfunction in hypertrophic cardiomyopathy: subgroup with unique clinical features. A segmental wall motion abnormality is an unusual finding in patients with hypertrophic cardiomyopathy. To clarify its clinical significance, 48 patients with hypertrophic cardiomyopathy were analyzed. Eight patients (Group A) had apical segmental dysfunction; 40 (Group B) had normal wall motion. No patient in either group had coronary artery stenosis on selective coronary arteriography. In all patients in Group A, apical segmental dysfunction was revealed by left ventriculography; however, it could be detected by echocardiography in only two patients in Group A. Left ventricular hypertrophy by electrocardiogram (ECG) was more common in Group B (p less than 0.05). Abnormal Q waves were more frequently discovered in Group A (p less than 0.005) and were recognized predominantly in the lateral leads. On serial ECGs, a gradual development of abnormal Q waves was noted in six of eight patients in Group A. Malignant arrhythmias were more common in Group A (p less than 0.001). In two patients in Group A, left ventricular dilation and congestive heart failure developed during the follow-up period. Thus, the presence of a Q wave in the lateral leads on an ECG in patients with hypertrophic cardiomyopathy may indicate the presence of apical segmental dysfunction. Left ventriculography should be performed to examine the presence of this abnormality and 24 h ambulatory ECG monitoring should be done to detect malignant arrhythmias in patients who have abnormal Q waves in the lateral leads. Patients with this unique type of hypertrophic cardiomyopathy need careful follow-up evaluation.
Mucinous adenocarcinoma of the submandibular gland. A rare tumor not easily classifiable among published histologic categories for salivary gland tumors is reported. The neoplasm developed within the submandibular gland of a 78-year-old woman with invasion of the mandible and metastasis to regional lymph nodes. Histopathologically, cuboidal cells possessing clear cytoplasm and displaced round nuclei proliferated and exhibited an adenomatous pattern. Many cystic spaces surrounded by tumor cell strands were seen, mucus substance filled in the cystic spaces, and the tumor cells seemed mucus-secreting, but neither epidermoid cells nor papillary appearance could be observed. Electromicroscopically, numerous mucous droplets of low electron density were prominent in the cytoplasm, and the tumor cells had sparse irregular microvilli on the luminal surface. Mucin histochemistry, including paradoxical concanavalin A staining, revealed that the tumor cells contained neutral and acid mucins, and these were identified as class II and III mucosubstances. No other neoplastic lesion, except recurrent metastatic neck nodes, has been detected 6 years after the first examination, and it seems that the tumor is a rare primary mucinous adenocarcinoma of the submandibular gland.
Effect of nisoldipine on hemodynamic responses to defibrillation. Sequences of ventricular fibrillation-defibrillation cause transient hypertension; we hypothesized that this "adrenergic overshoot" might be blunted by the functional antiadrenergic effect of the calcium channel blocking drug nisoldipine, with a potentially beneficial reduction in myocardial oxygen requirements. However, other calcium channel blocking drugs have been shown to reduce shock success for defibrillation, a deleterious effect. Thus the purposes of this study were to assess the effect of nisoldipine on the hemodynamic responses to the sequences of ventricular fibrillation-defibrillation, and its effect on the energy requirements for defibrillation. In 16 dogs we administered intravenous nisoldipine (1 microgram/kg bolus followed by an infusion of 0.075 to 0.50 microgram/kg/min) to lower mean blood pressure 10% and 20% below baseline. Ventricular fibrillation was induced electrically, and shocks of varying energy levels (30, 50, and 100 joules) were administered to determine defibrillation energy requirements. Heart rates and blood pressures were recorded up to 3 minutes after each shock to determine hemodynamic responses. Measurements were made before nisoldipine administration and again at the two levels of drug-induced blood pressure decline. We found that the usual systolic blood pressure "overshoot" after defibrillation (typically maximum at 15 to 30 seconds after shocks) was significantly blunted after nisoldipine administration (p less than 0.05). Heart rate slowing after defibrillation (a cholinergic response) was not affected. Nisoldipine did not alter shock success rates, which varied from 12 +/- 7%SE at 30 joules to 68 +/- 12% at 100 joules. Thus nisoldipine blunted the "adrenergic overshoot" of systolic blood pressure following defibrillation, a potentially beneficial effect, without altering the energy requirements for transthoracic defibrillation.
Changes in anal canal sensation after childbirth. Obstetic trauma predisposes to faecal incontinence. Anal canal sensation is impaired in incontinent patients. To assess the effect of childbirth on anal canal sensation anal mucosal electrosensitivity was measured in 122 primiparous patients in the immediate postnatal period and in 74 at 6 months postpartum. There were 35 normal vaginal deliveries, 36 forceps deliveries, 20 ventouse extractions, ten vaginal breech deliveries and 21 caesarean sections. Sensation was impaired in the lower, mid and upper anal canal immediately after delivery in those patients who had a normal vaginal delivery or a forceps delivery when compared with controls or with those delivered by caesarean section. Women who had ventouse deliveries had impaired sensation immediately after delivery in the mid anal canal compared with controls and those undergoing caesarean section. By 6 months there were no differences between any group. Patients who sustained a division of the external anal sphincter at delivery had impaired sensation which persisted in the upper anal canal at 6 months.
Sex reversal syndrome (XX male). Men who appear normal and live a normal life, may have a 46,XX karyotype and present with the typical features of infertility and end organ (testicular) failure. They are azoospermic and their small testicles show specific patterns on light and electron microscopy. Recent advances in genetics (1) favor the "X-Y interchange" theory to explain this phenomenon; (2) hypothesize about the roles of the H-Y antigen and testis determining factor (TDF) in determining "maleness"; and (3) allow mapping of the relative positions of H-Y and TDF loci on the Y chromosome.
Propafenone treatment of symptomatic paroxysmal supraventricular arrhythmias. A randomized, placebo-controlled, crossover trial in patients tolerating oral therapy. OBJECTIVE: To test the hypothesis that propafenone, administered orally, prevents symptomatic paroxysmal supraventricular arrhythmias. DESIGN: a 6-month, open-label, dose-finding phase followed by a randomized, double-blind, placebo-controlled, crossover phase, with each treatment period lasting up to 60 days. SETTING: An outpatient clinic. PATIENTS: Thirty-three patients with either paroxysmal supraventricular tachycardia (n = 16) or paroxysmal atrial fibrillation (n = 17) were enrolled. Their arrhythmias were documented by electrocardiogram before enrollment. Twenty-three patients (14 with paroxysmal supraventricular tachycardia and 9 with paroxysmal atrial fibrillation) were randomized and the data obtained from these patients were used in the efficacy analysis. INTERVENTION: Propafenone (300 mg three times daily in 19 patients, 300 mg twice daily in 3 patients, and 150 mg twice daily in 1 patient) and matching placebo tablets were administered in a randomized sequence. MEASUREMENTS: Symptomatic arrhythmia was documented by telephone transmission of the electrocardiogram. MAIN RESULTS: The time to first recurrence was prolonged for the overall group of 23 patients while they received propafenone (P = 0.004). The recurrence rate of arrhythmia during treatment with propafenone was estimated to be approximately one fifth of the recurrence rate during treatment with placebo. CONCLUSIONS: Propafenone is effective in reducing symptomatic paroxysmal supraventricular arrhythmias.
The role of the mast cell in clinical gastrointestinal disease with special reference to systemic mastocytosis. The gastrointestinal tract is a rich source of mast cells with an enormous surface area that permits a high degree of interaction between the mast cell and intestinal luminal contents. The active metabolic products of the mast cell influence gastrointestinal secretion, absorption, and motility through paracrine effects of local mast cell degranulation and also cause systemic effects through the release of cellular products into the blood stream. Systemic mastocytosis influences physiologic function through the systemic effects of mast cell products released from focal (e.g., bone marrow) or wide spread increases in mast cell number. Local gastrointestinal proliferation of mast cells in response to recognized (e.g., gluten in celiac sprue) or obscure stimuli can alter gastrointestinal function and induce systemic symptoms. Celiac sprue, inflammatory bowel disease, and non-ulcer dyspepsia are three examples of gastrointestinal diseases in which mast cells can be implicated in the pathophysiology of the symptoms.
Chromogranin A storage and secretion: sensitivity and specificity for the diagnosis of pheochromocytoma. Chromogranin A, co-stored and co-released with catecholamines from adrenal medullary and sympathetic neuronal vesicles, is elevated in the plasma of patients with pheochromocytoma. The usefulness of the hormone in the differential diagnosis of hypertension is examined. An elevated level of chromogranin A had comparable diagnostic sensitivity (83%, 24/29) to, but greater diagnostic specificity (96%, 86/90) than the level of plasma catecholamines when subjects with pheochromocytoma (n = 29) were evaluated in comparison to several reference groups, including normotensive controls (n = 49), subjects with essential hypertension (n = 28), subjects with renovascular hypertension (n = 5), and subjects with primary aldosteronism (n = 3). Subjects with signs or symptoms suggesting pheochromocytoma, but in whom the diagnosis was ultimately ruled out (n = 5) had normal plasma levels of chromogranin A. A modest rise in chromogranin A in those with essential hypertension, and correlation of chromogranin A with diastolic blood pressure in normotensive patients and patients with essential hypertension did not impair the diagnostic usefulness of chromogranin A for pheochromocytoma. Renal failure was associated with an elevated plasma chromogranin A independently of blood pressure. Plasma chromogranin A correlated with tumor mass, tumor chromogranin A content, tumor norepinephrine content, and urinary vanillylmandelic acid excretion; it did not correlate with plasma or urinary catecholamines, nor with blood pressure in patients with pheochromocytoma. Plasma chromogranin A levels did not differ in subjects with pheochromocytoma when stratified by age, sex, tumor location, or tumor pathology. Several drugs used in the diagnosis or treatment of pheochromocytoma (clonidine, metoprolol, phentolamine, and tyramine) had little effect on plasma chromogranin A concentration. Within the pheochromocytoma, chromogranin A was localized along with catecholamines to the soluble core of chromaffin granules, where it accounted for 18 +/- 5% of vesicle soluble protein. We conclude that 1) chromogranin A emerges along with catecholamines from pheochromocytoma chromaffin granules; 2) plasma chromogranin A is a sensitive and specific diagnostic tool in evaluation of actual or suspected pheochromocytoma; 3) plasma chromogranin A predicts pheochromocytoma tumor size and overall catecholamine production; and 4) drugs commonly employed in the diagnosis or treatment of pheochromocytoma have little effect on plasma chromogranin A level, preserving the usefulness of chromogranin A in evaluating pheochromocytoma. Thus, measurement of chromogranin A provides a useful adjunct to the diagnosis of pheochromocytoma.