123rc/medical_text huggingface dataset:
Congenital craniofacial anomalies of ophthalmic importance. Congenital craniofacial abnormalities frequently require ophthalmic evaluation and surgical management. Called upon to perform as part of the craniofacial team managing the often severely deformed craniofacial patient, the ophthalmologist must bring a basic knowledge of craniofacial syndromes and developmental anatomy, as well as clinical acumen to help preserve or improve ocular and adnexal function. As an introduction to this area of ophthalmology, the clinical features, classification, appropriate facial embryology, assessment and surgical considerations of the various congenital craniofacial abnormalities are reviewed. The expanding availability of craniofacial surgeons and surgical teams along with improved surgical results will ultimately require an increasing involvement by many more ophthalmologists in the evaluation and management of these congenital abnormalities.
Management decisions in laryngeal carcinoma in situ. Twenty-one patients with laryngeal carcinoma in situ (n = 12) or carcinoma in situ with microinvasion (n = 9) were treated with laser mucosal dissection of the vocal cords and/or superficial laser cordectomy. The normal architecture of the vocal cords was preserved because the depth of vaporization was usually superficial in these early cases. Five patients had recurrence, new tumor, or persistence of abnormal tissue that required additional laser surgical treatments. With a follow-up range of 6 months to 4 years, all patients currently are free of laryngeal abnormality, and no patient has needed open laryngeal surgery or radiation therapy. Transoral endoscopic laser resection of laryngeal carcinoma in situ with or without microinvasion should be the treatment of choice for these early lesions.
Norwalk virus genome cloning and characterization. Major epidemic outbreaks of acute gastroenteritis result from infections with Norwalk or Norwalk-like viruses. Virus purified from stool specimens of volunteers experimentally infected with Norwalk virus was used to construct recombinant complementary DNA (cDNA) and derive clones representing most of the viral genome. The specificity of the clones was shown by their hybridization with post- (but not pre-) infection stool samples from volunteers infected with Norwalk virus and with purified Norwalk virus. A correlation was observed between the appearance of hybridization signals in stool samples and clinical symptoms of acute gastroenteritis in volunteers. Hybridization assays between overlapping clones, restriction enzyme analyses, and partial nucleotide sequence information of the clones indicated that Norwalk virus contains a single-stranded RNA genome of positive sense, with a polyadenylated tail at the 3' end and a size of at least 7.5 kilobases. A consensus amino acid sequence motif typical of viral RNA-dependent RNA polymerases was identified in one of the Norwalk virus clones. The availability of Norwalk-specific cDNA and the new sequence information of the viral genome should permit the development of sensitive diagnostic assays and studies of the molecular biology of the virus.
Recent trends in cesarean section use in California. Cesarean section use in the United States has increased to 24.7% of deliveries in 1988 and is the most common hospital surgical procedure. California cesarean section rates were examined to measure recent trends in obstetric practices and to project future patterns of cesarean section use. Using discharge abstracts from 1983 to 1987 California hospital deliveries, total cesarean section rates were found to increase from nearly 22% in 1983 to 25% in 1987, an increase of 15%. Using a series of least-squares regression models, time trends in the distribution of indications associated with cesarean section among all deliveries and indication-specific cesarean section rates were evaluated. Increases in the number of women with previous cesarean section and fetal distress contributed to rising cesarean section rates. In addition, indication-specific cesarean section rates increased for breech presentation and dystocia. These trends were counterbalanced, in part, by declining rates of repeat cesarean sections. Trends noted for July 1985 through 1987 did not differ substantially from those observed for January 1983 to June 1985, suggesting that recent policy attempts to alter cesarean section use have not had a measurable effect on existing trends. Projections suggest that California cesarean section rates will rise to a level of 34% by the year 2000.
Diagnostic quality and complications of hysterosalpingography: oil- versus water-soluble contrast media--a randomized prospective study. In a prospective randomized study of 417 patients, side effects and complications of contrast media and the diagnostic quality of images obtained after hysterosalpingography (HSG) were evaluated after use of diatrizoate meglumine (104 patients), ioxaglate (105 patients), iohexol (105 patients), or ethiodized poppy-seed oil (103 patients). The authors detected no differences among these groups in the prevalence of pain during HSG. The prevalence of lower abdominal pain and vaginal bleeding after HSG was significantly lower in the group that received ethiodized poppy-seed oil than in the three other groups. The prevalence of pelvic infection or inflammation was significantly lower with ethiodized poppy-seed oil than with water-soluble media. All contrast media provided acceptable diagnostic image quality with regard to fallopian tubes, peritoneal spill, and intraperitoneal distribution. Visualization of the uterine cavity and ampullary rugae was significantly better with water-soluble media than with ethiodized poppy-seed oil, which was associated with a high conception rate and which the authors consider preferable for HSG.
Magnetic resonance imaging--the evaluation of choice in residual shunt after congenital heart disease surgery? Accurate anatomic diagnosis presents a dilemma in patients with residual shunt after corrective surgery for congenital heart disease. We describe a patient who, after atrial septal defect repair, developed dyspnea and central cyanosis despite normal pulmonary arterial pressures and right heart chamber size. A role for early MRI is suggested.
Glutathione disulfide formation and oxidant stress during acetaminophen-induced hepatotoxicity in mice in vivo: the protective effect of allopurinol. Acetaminophen (500 mg/kg i.p.) induced hepatotoxicity in fasted ICR mice in vivo. Acetaminophen also caused a long-lasting 50% reduction of the hepatic ATP content, an irreversible loss of hepatic xanthine dehydrogenase activity and a transient increase of the xanthine oxidase activity. All effects occurred before parenchymal cell damage, i.e., the release of cellular enzymes. The hepatic content of GSH and GSSG was initially depleted by acetaminophen without affecting the GSSG:GSH ratio (1:200), however, during the recovery phase of the hepatic GSH levels the GSSG content increased faster than GSH, resulting in a GSSG:GSH ratio of 1:18 24 h after acetaminophen administration. The mitochondrial GSSG content increased from 2% in controls to greater than 20% in acetaminophen-treated mice. The extremely elevated tissue GSSG levels were accompanied by a 4-fold increase of the plasma GSSG concentrations but not by an enhanced biliary efflux, although hepatic GSSG formation and biliary excretion were not affected by acetaminophen. Allopurinol protected dose-dependently against acetaminophen-induced cell injury, the loss of ATP and the increase of the GSSG content in the total liver and in the mitochondrial compartment without inhibiting reactive metabolite formation. High, protective as well as low, nonprotective doses of allopurinol almost completely inhibited hepatic xanthine oxidase and dehydrogenase activity, but only high doses prevented the increase of the mitochondrial GSSG content. The data indicate a long-lasting, primarily intracellular oxidant stress during the progression phase of acetaminophen-induced cell necrosis. The protective effect of allopurinol is unlikely to involve the inhibition of reactive oxygen formation by xanthine oxidase but could be the result of its antioxidant property.
Treatment of chronic relapsing inflammatory demyelinating polyneuropathy by cyclosporin A and plasma exchange. A case report. A patient with chronic relapsing inflammatory demyelinating polyneuropathy was successfully treated with plasma exchanges and cyclosporin A (CsA). Dynamometric measurements of hand force during the time of CsA treatment showed a highly significant correlation between hand force and CsA blood levels. The largest influence of CsA on hand force occurred 11-13 days after CsA uptake.
Definition of the role of contemporary surgical management in cisternal and parenchymatous cysticercosis cerebri. With increasing immigration from endemic regions, the incidence of neurocysticercosis in North America is rising. This retrospective study was undertaken to examine the role of surgery in those cases presenting with large cystic parenchymal and cisternal lesions in the current era of anthelminthic agents administered orally. A total of 237 patients presented with newly diagnosed neurocysticercosis to our institution over a recent 5-year period (mean age, 31.2 years). Among those who presented with cystic mass lesions predominantly affecting the brain parenchyma and cisternal spaces, 20 (8.4%; mean age, 40.2 years) with large cystic lesions subsequently underwent surgical intervention, either because of an emergent presentation or because they were refractory to medical management. Clinical presentation included increased intracranial pressure, focal neurological deficit, and seizure. Radiographic imaging (computed tomography and/or magnetic resonance imaging) demonstrated 12 cases with cisternal lesions, 7 with parenchymal lesions, and 1 involving both compartments. Based on imaging guidelines, 30 operative procedures (excluding shunt revisions) were performed (14 craniotomies, 8 cerebrospinal fluid diversions, 7 stereotactic procedures, and 1 burr hole drainage). Fifteen (75%) showed neurological or symptomatic improvement over a median follow-up period of 36.4 months. There were three surgery-related complications and no deaths.
Intracranial complications of paranasal sinusitis: a combined institutional review. Intracranial complications of paranasal sinusitis constitute true surgical and medical emergencies. The charts of all patients (n = 649) admitted for acute or chronic sinusitis to the University of Minnesota Hospital and to the University of Michigan Medical Center during a 13-year period (1975 to 1988) were retrospectively reviewed to determine the incidence of complications. The clinical presentation, bacteriology, involved sinuses, influencing host factors, white blood cell count on presentation, length of hospitalization, and postinterventional complications are presented. Twenty-four patients with intracranial complications from paranasal sinusitis are studied for an incidence of 3.7%. Aggressive medical and semi-emergent surgical intervention are required to prevent excessive morbidity and/or mortality. Intracranial complications included subdural empyema, frontal lobe abscesses, intrahemispheric abscesses, cavernous and superior sagittal sinus thrombosis, and osteomyelitis.
Misdiagnosis in patients with amyotrophic lateral sclerosis. To confirm our impression that a high percentage of patients with amyotrophic lateral sclerosis are initially misdiagnosed, we reviewed records of 33 patients with a definitive diagnosis of amyotrophic lateral sclerosis seen over 10 years. Fourteen patients (43%) were initially misdiagnosed. Mean time to correct diagnosis was significantly greater for the misdiagnosed group (16.0 +/- 9.3 months) than for the rest of the patients (7.6 +/- 4.1 months). Two of three patients with an initial symptom of dyspnea were misdiagnosed. Three patients underwent laminectomies because of misdiagnosis. Age, stage of disease, and unusual presenting symptoms were not identified as causes of misdiagnosis. Most likely causes were physicians' failure to consider the diagnosis and lack of familiarity with the common clinical presentations of amyotrophic lateral sclerosis. Earlier diagnosis of amyotrophic lateral sclerosis may help prevent medical mismanagement and may benefit patients both medically and psychologically.
Sunlight and dysplastic nevus risk. Results of a clinic-based case-control study. The dysplastic nevus (DN) is the most important risk factor and precursor for malignant melanoma. The authors compared the responses of 132 consecutive cases of DN, 186 consecutive cases of cutaneous melanoma, and 239 controls attending the same subspecialty clinic to questions regarding sun sensitivity, sun exposure, and other possible risk factors. Dysplastic nevus cases were younger than controls and were of a higher social class, as indicated by more years of formal education. Sun sensitivity (assessed by reported depth of tan after multiple exposures) was associated with both DN risk and melanoma risk after controlling for age and education in logistic regression analysis (P = 0.009 and 0.03, respectively), but for DN risk this association was nonlinear: the relative risks (versus deep tan) were 2.3 for average tanners, 2.8 for light tanners, and 1.6 for those who reported practically no tan. Sun exposure measures were not associated with DN risk after controlling for age and education, whether or not depth of tan was controlled in the analysis. These observations suggest a role for either sunlight or a trait linked with sun sensitivity in the development of dysplastic nevi.
A histopathologic study of spinal cord ischemia using an isohistogenic rat upper-half-body transplantation model. To study the histopathologic changes of spinal cords exposed to long-duration complete ischemia, the authors developed an upper-half-body transplantation model of inbred rat. In this model, an infant Lewis rat is transplanted to the inguinal region of another adult Lewis rat using microsurgical vascular anastomosis. Even when 2-week-old donor rats were exposed to complete ischemia for 90 minutes, functions of the spinal cord were comparatively preserved. In histopathologic observations, degeneration proportional to complete ischemia duration was noted. In the 60-minute ischemia group of 2-week-old donor rats, however, no substantial differences from normal spinal cord were observed. Under conditions of equal ischemia duration, it appeared the younger animal had the greater ischemic tolerance.
Response of angiographically normal and atherosclerotic left anterior descending coronary arteries to acetylcholine. Acetylcholine-induced constriction of human coronary arteries in vivo is commonly attributed to endothelial dysfunction. To examine the effects of 2 other important determinants of vascular responses--namely, agonist concentration and the segment of circulation under study--the diameters of proximal, middle and distal segments of the left anterior descending artery (LAD) and coronary sinus oxygen saturation were measured in 10 patients with angiographically normal coronary arteries (group 1) and in 7 patients with coronary atherosclerosis (group 2) after intracoronary acetylcholine was infused at concentrations from 10(-7)M to between 10(-4)M and 10(-2)M. In group 1, acetylcholine caused minor (less than or equal to 6%) but progressive dilatation of the LAD up to 10(-4)M, but constriction, particularly of the distal segments and tertiary branches, occurred at higher concentrations. Over the same concentration range, coronary sinus oxygen saturation rose progressively from a basal level of 36 +/- 3% to a maximum of 72 +/- 3% in the absence of changes in heart rate and blood pressure, suggesting marked progressive dilatation of resistance vessels. Concentrations greater than or equal to 10(-3)M caused intense constriction of distal epicardial vessels and, in some cases, anginal pain and objective signs of ischemia. Conversely, in group 2, acetylcholine (infused only up to 10(-4)M for ethical reasons) failed to cause significant changes in LAD diameter. These data suggest that the local acetylcholine concentration and coronary vascular segment under study may determine the observed response to at least an equivalent extent as does the presence or absence of coronary atherosclerosis, raising the question of whether a constrictor response to intracoronary acetylcholine reliably indicates the presence of coronary atherosclerosis.
Invasive squamous cell carcinoma of the mandible presenting as a chronic osteomyelitis: report of a case. A case of invasive squamous cell carcinoma of the mandible initially thought to be chronic osteomyelitis is reviewed. Discussion of the origin of the tumor and several imaging techniques used for differentiating maxillofacial infection from neoplasm are discussed. The difficulty of diagnosis of chronic painful maxillofacial lesions illustrates the need for a high degree of suspicion concerning any inflammatory lesion not responding to appropriate therapy. Accurate diagnosis and treatment of such lesions most often necessitates microscopic examination.
Systemic to pulmonary bronchial blood flow in mitral stenosis. We measured systemic to pulmonary bronchial blood flow [Qbr(s-p)] during total cardiopulmonary bypass in 15 patients with mitral stenosis and elevated pulmonary venous pressure (group A, mean pulmonary wedge pressure = 22.2 +/- 5.4 mm Hg, mean +/- SD) and in 15 patients with coronary artery diseases and normal pulmonary venous pressure (group B). Qbr(s-p) is the volume of blood accumulating in the left side of the heart in the absence of pulmonary and coronary flows. This blood was vented through a cannula introduced into the left atrium and measured. Qbr(s-p) was 76.3 +/- 13.9 ml/min (2.18 +/- 0.37 percent of extracorporeal circulation pump flow) and 22.3 +/- 2.1 (0.63 +/- 0.15) in group A and B, respectively (p less than 0.01). During total cardiopulmonary bypass, pulmonary venous pressure is approximately atmospheric pressure, and no differences in systemic blood pressure, extracorporeal circulation pump flow, and airways pressure were observed between group A and B. Therefore, vascular resistance through the bronchial vessels draining into the pulmonary circulation is reduced in patients with mitral stenosis and elevated pulmonary venous pressure.
Etoposide in the management of metastatic breast cancer. Etoposide, despite extensive use in other malignancies, has played a minor role in the treatment of patients with breast cancer. Single-agent trials in which etoposide is administered to heavily pretreated patients with metastatic breast cancer have demonstrated a low overall response rate (6.6% of 383 patients), with no convincing evidence for either schedule dependence or a relationship between dose intensity and response. The sole single-agent trial in previously untreated patients suggested that the drug has an approximately 15% response rate in untreated patients. Combination therapy trials in which etoposide has been combined with either cyclophosphamide, doxorubicin, or cisplatin have not yet convincingly demonstrated superiority over any of these drugs as single agents, although cisplatin plus etoposide appears to be superior to either agent alone. In vitro studies suggest that pretreating hormone-sensitive breast cancer cells with estradiol may increase their sensitivity to etoposide-induced DNA cleavage. This may represent a future direction in the use of etoposide in breast cancer. Currently, however, the use of etoposide in breast cancer should be considered investigational.
Coronary artery bypass grafting in elderly patients. Comparative results in a consecutive series of 469 patients older than 75 years. A consecutive series of 7104 patients undergoing isolated coronary artery bypass grafting during an 18-year period (1971 to 1988) included 469 patients older than 75 years. Results were analyzed to determine comparative risk factors for morbidity, early and late survival, and functional outcome. Patients younger than 75 years (group I) and patients older than 75 years (group II) were identical for ejection fraction and standard hemodynamic indices. Mean number of grafts and crossclamp time were greater for group II patients (p less than 0.01). Mean age of group I was 58.6 years and group II, 77.6 years (p less than 0.01). Women composed 19.7% (1308/6635) of group I and 36.2% (170/469) of group II patients (p less than 0.05). Mammary grafts were placed in 57.7% (3830/6635) of group I and 41.6% (195/469) of group II patients (p less than 0.05). Overall perioperative mortality rate was 2.1% for group I and 6.8% for group II (p less than 0.05). Perioperative myocardial infarction rate was similar for the two groups. Ventricular and supraventricular arrhythmias, renal insufficiency, neurologic complications, prolonged ventilatory support, increased hospital cost, and prolonged hospitalization were significantly more prevalent (all p less than 0.05) in patients older than 75 years. Five and 10 years postoperatively, there were no significant differences between groups I and II with regard to event-free status including angina, myocardial infarction, and reoperation. The 5-year survival rate was 92% for group I and 80% for group II (p less than 0.05), similar to that of age-matched control subjects. The significantly increased potential for complications and expense of coronary bypass in patients over 75 years of age mandates judicious patient selection and preoperative counseling. Despite a significantly increased early mortality and an anticipated decreased long-term survival paralleling normal life table survival curves, good intermediate functional improvement can be realized in patients older than 75 years, comparable with that expected in a much younger age group.
Intravenous but not intracolonic epidermal growth factor maintains colonocyte proliferation in defunctioned rat colorectum. The role of epidermal growth factor in the proliferation of normal and premalignant colonocytes in vivo is not fully understood. In particular, the relative importance of its possible systemic and intraluminal routes of action has not been fully clarified. Rats with surgically defunctioned distal colorectums were used, and mini osmotic pumps were implanted to study the effects of intraluminal and IV administration of epidermal growth factor on colonocyte proliferation. Within 2 weeks of bypass, colonocyte proliferation in defunctioned colorectum has decreased to about one third the rate in normal colorectum or in colorectum proximal to the defunctioning colostomy. Intraluminal epidermal growth factor, infused from the time of operation did not reverse this hypoplasia, whereas IV epidermal growth factor maintained colonocyte proliferation at approximately the normal rate in bypassed colorectum. This model is suitable for testing other putative colonic mitogens for possible intraluminal and systemic effects.