shukoor65/lab-rag-model huggingface dataset:
Relation of early hemodynamic changes to final cardiac phenotype and survival after neural crest ablation in chick embryos. BACKGROUND. Microcinephotography was used to study a model of persistent truncus arteriosus created in chick embryos by ablation of premigratory neural crest destined for the third and fourth aortic arch arteries as well as the septum of the cardiac outflow tract. METHODS AND RESULTS. Twenty-five control embryos and 105 of 202 experimental embryos were filmed on day 3 of incubation and then reincubated. The remaining 97 experimental embryos were not filmed because of twisting of the embryos, but they were reincubated. There was no difference in either the survival rate (p greater than 0.23) from day 3 to day 11 of incubation or the incidence of persistent truncus arteriosus (p greater than 0.08) between the filmed and the nonfilmed embryos. Incomplete looping of the cardiac tube observed in experimental embryos during early cardiogenesis correlated with a right ventricular origin of the outflow vessels in the definitive heart. Hemodynamic measurements indicated that there was no difference in heart rate, ejection fraction, systolic and diastolic areas, stroke volume, and cardiac output between controls and the experimental group as a whole. However, embryos that did not survive to day 11 had decreased stroke volume (p less than 0.001) and cardiac output (p less than 0.001), whereas embryos that survived to day 11 with cardiac malformations had increased stroke volume and cardiac output in early embryogenesis. CONCLUSIONS. Increased stroke volume and cardiac output may be necessary factors for survival in embryos with cardiac dysmorphogenesis and probably are associated with dilation of the ventricular portion of the cardiac tube, which leads to malalignment of the outflow vessel or vessels.
Serious bacterial infections in children. When can outpatient treatment be used? Several studies now support outpatient treatment of many serious bacterial infections in children, such as periorbital or buccal cellulitis, urinary tract infection, pneumonia, and abscess. However, an appropriate agent, that is, a third-generation cephalosporin with a long half-life, must be available and its effectiveness properly researched. In addition, children must be free of other illnesses and able to ingest fluids and maintain hydration, and their parents must be willing and able to cooperate with an outpatient treatment regimen. Family physicians can maintain the close patient and family contact needed to facilitate this form of therapy.
Antibiotic therapy of intra-abdominal sepsis in the elderly: experience with ticarcillin and clavulanic acid. Age is a major factor in determining the outcome for older patients with intra-abdominal sepsis. Poor outcome in these patients may be related to a number of physiologic and immunologic changes associated with aging. The treatment of intra-abdominal sepsis can itself pose special risks for the elderly. Standard regimens containing aminoglycosides have a substantial risk of nephrotoxicity, which is magnified in elderly patients. Alternatives to standard aminoglycoside-containing regimens, therefore, are desirable. Most intra-abdominal infections involve multiple pathogens, usually both aerobic and anaerobic. The polymicrobial nature of intra-abdominal sepsis mandates antimicrobial chemotherapy effective against a broad range of organisms. In the past several years, a host of new antibiotics have been introduced that used alone or in combination with other drugs has the potential of safely avoiding aminoglycosides in many patients with intra-abdominal sepsis. One such agent, ticarcillin with clavulanate potassium, is active against a wide spectrum of aerobic and anaerobic pathogens. In a prospective, randomized, open label trial, ticarcillin and clavulanate was compared with gentamicin and clindamycin. Although the sample size was too small to allow meaningful statistical comparisons of efficacy and safety, both regimens were effective and well tolerated. In general, prolonged administration of aminoglycosides is rarely indicated for the treatment of intra-abdominal sepsis in the elderly, although initial empiric use of aminoglycosides may sometimes be warranted.
Quantitative electroencephalography: a report on the present state of computerized EEG techniques. American Psychiatric Association Task Force on Quantitative Electrophysiological Assessment. The American Psychiatric Association established the Task Force on Quantitative Electrophysiological Assessment in May 1989 to consider several questions of interest to psychiatrists. From the inception of techniques for quantitative electroencephalography (qEEG), the possibility was raised that it would substantially assist in the diagnosis of brain disorders. However, controversy exists over the scientific basis for such approaches and the training necessary for interpretation of computerized records. The task force's charge was to report 1) the present state of scientific knowledge about qEEG, 2) the role of qEEG in clinical psychiatric practice at the present time, 3) the training necessary for the use of qEEG techniques, and 4) the possible future of the technique in the study of mental disorders. The task force concluded that qEEG is particularly useful for the detection of abnormalities in slow waves, which are a feature of delirium, dementia, intoxication, and other syndromes involving gross CNS dysfunction. The ability of qEEG to help in the diagnosis of other disorders, such as schizophrenia or depression, is not yet established. Clinical replications and sharing of normative and patient data bases are necessary for the advancement of this field. Proper use of this technique requires extensive training in a center experienced in its use. Standards for training and for using the technology in psychiatry are urgently needed. This report was approved by the Board of Trustees in December 1990.
Mandatory trial of labor after cesarean delivery: an alternative viewpoint Twelve women experienced major rupture of the uterus during a trial of labor after previous cesarean (low transverse cervical incision in 11, low vertical in one). Two women required hysterectomy and a third had serious postoperative complications. There were three perinatal deaths, and two infants suffered significant long-term neurologic impairment. Although vaginal birth after cesarean delivery is considered safe in most instances, these cases serve as a reminder that catastrophic events can occur. Potential complications have important implications for clinicians when counseling patients about the route of delivery and for the management of any trial of labor after cesarean delivery.
High-speed memory scanning in Parkinson's disease: adverse effects of levodopa. High-speed memory scanning as assessed by the Sternberg paradigm was studied in 12 nondemented patients with fluctuating Parkinson's disease and 13 age-matched healthy controls. Patients were first assessed before taking their morning dose of levodopa ("off") and again after that dose had produced full clinical effect ("on") after that dose had produced full clinical effect ("on"). Although motor components of the measured choice reaction time were slower in patients when off than in control subjects, memory scanning speed was not different. After levodopa (on), patients' motor time normalized, but cognitive processing speed became significantly slower when compared with previous performance in the off condition and with controls. Contrary to previous concepts of bradyphrenia in patients with Parkinson's disease, these results indicate that dopaminergic stimulation can reduce cognitive processing speed.
Preparedness of practicing pediatricians to manage emergencies. To determine pediatrician preparedness to manage emergencies, a nationally representative random sample of 1000 non-hospital-based pediatricians was surveyed about (1) types of emergencies encountered and methods of transport to an emergency facility, (2) availability and use of equipment and medications in the office, and (3) determinants of pediatrician confidence in managing emergencies. The proportion of pediatricians who had encountered specific emergencies ranged from 86% for meningitis to 22% for cardiopulmonary arrest. The majority transported acutely ill children to an emergency department by ambulance. Availability of individual pieces of equipment and medications in offices ranged from 97% for epinephrine 1:1000 to 11% for bone marrow needles for intraosseous access. Combination of equipment available to manage particular emergencies ranged from 61% for severe dehydration to 11% for cardiopulmonary arrest. The equipment available in a pediatrician's office was significantly related to the type of primary work setting. Pediatrician confidence in managing the initial stabilization of emergencies ranged from 58% for seizures to 25% for epiglottitis. Confidence was related significantly to year residency was completed, Advanced Cardiac or Advanced Pediatric Life Support training, work setting, and the availability of equipment in the office. Continuing education regarding initial office management of and equipment for common emergencies should improve the pediatrician's confidence and competence in this area.
Brainstem compression by basilar artery anomalies as visualized by MRI. The use of MRI in the diagnosis of vascular anomalies of the basilar artery is demonstrated in two cases. The first patient had a partially thrombosed giant aneurysm of the basilar artery; the second had an atypical course of the basilar artery. MRI is indicated whenever other imaging procedures do not provide a definite diagnosis or the use of contrast medium for conventional X-ray examination or computed tomography is contraindicated.
A new look at postoperative instructions following cataract extraction. We sought to determine whether, given the decreasing rate of complications associated with cataract surgery and IOL implantation, postoperative restrictions placed on patients undergoing these procedures could be significantly and safely relaxed. We reviewed the charts of 216 patients who had undergone capsulorhexis or "can-opener" capsulotomy, phacoemulsification, and insertion of an oval IOL over a 3-year period, noting any operative or postoperative complications. All of these patients had been examined the day after surgery and, if no complications were noted, had been instructed only to refrain from activities that produced pain. No shield was required, and no instructions were given to restrict showering, hair washing, or any other normal physical activity. We found no complications related to any postoperative activity. These results suggest that current postoperative instructions typically restricting such patients' activities should be reevaluated.
Coronary thrombosis: pathogenesis and clinical manifestations. The majority (greater than 75%) of major coronary thrombi are precipitated by a sudden rupture of the surface of an atherosclerotic plaque (plaque fissuring) causing platelet aggregation where thrombogenic subendothelial tissue has been exposed. Whether the thrombus remains mural and limited, just sealing the rupture, or evolves into an occlusive thrombus seems to depend on: (1) the amount and character of exposed thrombogenic material; (2) the actual thrombotic-thrombolytic equilibrium; and (3) local flow disturbances due to preexisting atherosclerotic stenosis. Thrombus formation may take place within the stenosis, where blood velocity and shear forces are highest, or it may take place or extend poststenotically, where flow separation, recirculation, and turbulence prevail. Platelet aggregation within the stenosis is responsible for the primary flow obstruction, but fibrin subsequently enmeshes the platelets and thus stabilizes the thrombus. Most thrombi have a layered structure, indicating an episodic growth that may alternate with thrombus fragmentation and peripheral embolization: thrombosis and thrombolysis are dynamic processes occurring simultaneously. If the platelet-rich thrombus at the rupture site evolves into an occlusive thrombus, the blood proximal and distal to the occlusion may stagnate and coagulate, giving rise to a secondarily formed red stagnation thrombosis consisting predominantly of erythrocytes held together by fibrin membranes. A ruptured plaque with a dynamic thrombosis superimposed (with or without spasm) seems to underlie the great majority of acute ischemic syndromes: unstable angina, acute infarction, and sudden death. The clinical presentation and the outcome depend on the severity and duration of ischemia: whether the obstruction is occlusive or nonocclusive, transient or persistent--modified by the magnitude of collateral flow.
Ultrastructural and immunohistochemical features of coronal adenomas. We studied by electron microscopy three coronal adenomas discovered incidentally in eyes removed surgically. Tumor cells displayed prominent intercellular interdigitations with numerous desmosomes, mitochondria, abundant rough endoplasmic reticulum, and nuclei with membrane infoldings and a granular chromatin pattern. In these characteristics, the tumor cells were identical to nonpigmented ciliary epithelium of the ciliary processes. These growths contained abundant extracellular material, which showed a dimorphic pattern of complex reduplicated basal lamina and granular areas without structure. Immunohistochemical studies on formalin-fixed, paraffin-embedded coronal adenomas demonstrated type IV collagen and laminin in the extracellular material. These findings confirm that coronal adenomas develop from nonpigmented ciliary epithelium and that the extracellular material of these tumors contains components normally present in basement membranes.
The intraoperative management of the thyroid gland during laryngectomy. The standard of care of laryngeal cancer surgery is wide field excision of the larynx combined with ipsilateral thyroid lobectomy. A retrospective review of 247 laryngectomies performed between 1979 and 1989 was undertaken to determine specific intraoperative indications for thyroid gland removal. The incidence of thyroid disease in our patients with laryngeal cancer was compared to the normal population. Eight percent of thyroid specimens removed during laryngeal cancer surgery demonstrated invasion by squamous cell carcinoma. All patients having thyroid invasion had T3 or T4 laryngeal lesions that were stage IV at the time of surgery. All these lesions were found to have transglottic growth and laryngeal cartilage invasion by the pathologist. All of these patients also had abnormal thyroid glands intraoperatively and laryngeal cartilage destruction that was evident intraoperatively. Total thyroidectomy with bilateral paratracheal and pretracheal lymph node dissection is indicated when squamous cell carcinoma of the larynx involves the thyroid gland. Prophylactic ipsilateral thyroid lobectomy and isthmusectomy is warranted for large laryngeal cancers (T3, T4) that involve the anterior commissure, the subglottic area, or extend transglottically. Routine thyroid gland removal is not indicated for the majority of laryngeal cancers that do not meet the aforementioned criteria. Finally, abnormal thyroid histopathology was diagnosed in 37% of the surgical thyroid gland specimens removed during laryngectomy.
DNA methylation profiles in the human genes for tumor necrosis factors alpha and beta in subpopulations of leukocytes and in leukemias. The genomic sequencing technique has been applied to assess the state of methylation in the DNA from human leukocyte subpopulations from healthy individuals and in the DNA from several individuals with myeloid or lymphatic leukemias or non-Hodgkin lymphomas. Leukocyte populations were purified by the high-gradient magnetic cell sorting technique. In the human tumor necrosis factor alpha (TNF-alpha) gene segment between nucleotides 300 and 1150, the specific methylation profile in the DNA from human granulocytes and monocytes is maintained in three cases of myeloid leukemia. In one such case, all 5-methyl-2'-deoxycytidine residues have been replaced by cytidine. In a chronic lymphatic T-cell leukemia, all 5-methyl-2'-deoxycytidine residues have been substituted by cytidine. In normal B lymphocytes, in two cases of chronic lymphatic B-cell leukemias and two cases of non-Hodgkin lymphomas, all 5'-CG-3' sequences in this gene segment are devoid of methylation. In the TNF-beta gene, DNA methylation is decreased in several examples of acute or chronic myeloid leukemias in comparison to normal human granulocytes or monocytes, whose DNA is almost completely methylated between nucleotides 700 and 900. In human T and B lymphocytes, the main producers of TNF-beta, in three instances of chronic lymphatic leukemias and two cases of non-Hodgkin lymphomas, all 5'-CG-3' sequences are unmethylated in this region. The DNA from the human HeLa cell line is highly methylated at all 5'-CG-3' sequences in the TNF-alpha and -beta genes. The TNF-alpha gene is transcribed in the cells of one case of acute myeloid leukemia in which the analyzed region of the TNF-alpha gene is completely unmethylated. The TNF-beta gene is not transcribed in any of the malignant cells tested.
Childhood sexual abuse in patients with paradoxical vocal cord dysfunction. We present three prototypical cases of paradoxical vocal cord dysfunction. The symptoms of this functional disorder mimic those of bronchial asthma attacks. These patients typically have experienced extensive medical intervention including intubation and corticosteroid use. We identify a history of childhood sexual abuse as an important factor contributing to the development of this psychosomatic disorder. We discuss the severity of psychopathology in patients with paradoxical vocal cord dysfunction and how this physical symptom may have developed to express psychological difficulties.
Partial, non-thrombotic, superior sagittal sinus occlusion due to occipital skull tumours. Two cases are described in which raised intracranial pressure occurred as a result of superior sagittal sinus (SSS) occlusion by an occipital skull tumour. One was a plasmacytoma, the other a metastatic deposit from a Ewing's sarcoma. The difficulties in diagnosis of this syndrome are illustrated together with the importance and success of appropriate treatment. From the literature it appears possible that these two tumours may be particularly likely to occlude the SSS and the reasons for this are discussed.
Magnetic resonance imaging vs palpation of cervical lymph node metastasis. In a series of 100 patients with head and neck carcinoma, the preoperative histopathologic findings of palpation and magnetic resonance imaging were compared with regard to both laterality and lymph node level (I through V). The overall error for palpation in detecting affected sides was 32%. Gadolinium-enhanced magnetic resonance images reliably upgraded 60% of the clinically negative necks, the overall error of magnetic resonance imaging being 16%. However, for both modalities, the sensitivity per level was too low to allow for selective neck dissections in case of only one positive level. These findings show that apart from primary tumor grading, magnetic resonance imaging can improve the preoperative grading of cervical lymph nodes. In selected cases, this may change the treatment plan to a "wait-and-see" policy or a more conservative type of neck dissection.
Fatal disseminated hemorrhagic toxoplasmic encephalitis as the initial manifestation of AIDS. A 28-year-old woman presented with progressive coma after being asymptomatic for 1 year after the demonstration of seropositivity for human immunodeficiency virus and high serum immunoglobulin G toxoplasma titers. Computed tomographic scanning showed multiple rounded cerebral hemorrhages and massive cerebral edema. Postmortem examination disclosed Toxoplasma gondii cysts scattered throughout the brain. An overwhelming fatal toxoplasmosis associated with multiple cerebral hemorrhages may be the first presentation of the acquired immunodeficiency syndrome. We raise the possibility that frequent neuroradiological monitoring may be indicated in asymptomatic human immunodeficiency virus-infected patients with high immunoglobulin G toxoplasma titers.
Thrombolysis in postinfarction angina. Postinfarction angina carries a poor prognosis, with a 20-70% incidence of recurrent myocardial infarction (MI) or death within the subsequent 3-6 months. The pathophysiologic mechanisms causing postinfarction angina may include thrombus, complex coronary arterial lesions that form a nidus for thrombus formation, inadequate collateral supply following acute MI, or intimal endothelial dysfunction. The role of thrombus has been established in the pathophysiology of Q-wave MI, and thrombolytic treatment of patients presenting with acute transmural MI has been shown to salvage left ventricular function and to reduce mortality. However, thrombolytic therapy for the acute MI does not reduce the incidence of recurrent ischemia or infarction, as is evident from the 18-26% incidence of recurrent ischemia reported in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) and Thrombolysis in Myocardial Infarction (TIMI) trials. In the Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico (GISSI) study the incidence of reinfarction was documented as 4% in the streptokinase group, which was actually significantly greater than in the placebo group (2%). In a randomized placebo-controlled study of thrombolysis for postinfarction angina, 29 patients were randomized to placebo (P group, n = 17) or to thrombolytic therapy (T group, n = 12). Patient groups were similar with respect to age, location of MI, ejection fraction, severity of coronary artery disease, and antianginal therapy. Patients underwent coronary angiography 6 +/- 1 days postinfarction. Filling defects consistent with intracoronary thrombus was seen in 11 of 12 T group patients and in 11 of 17 P group patients prior to treatment. Lysis occurred in 7 of 11 T patients and 1 of 11 P (p less than 0.02). Holter-detected silent ischemia was compared pre- and posttherapy.
Topical amethocaine in strabismus surgery. A randomized study was performed to assess the effect of topical 1% amethocaine hydrochloride on postoperative analgesia requirements after strabismus surgery. Forty children scheduled for elective operation were allocated randomly to receive either topical amethocaine or normal saline. Postoperative analgesia was evaluated with the use of a four-point assessment score and analgesic requirements. The topical amethocaine provided significantly better postoperative analgesia (p less than 0.001) as measured by both the assessment score and the postoperative analgesia requirement.
Primary carcinoid of the common bile duct. Immunohistochemical characterization of a case and review of the literature. A 39-year-old woman with a primary carcinoid of the common bile duct is presented. The tumor showed argyrophilia; and, by immunohistochemical studies, chromogranin, serotonin, and somatostatin were demonstrated. The patient has no symptoms 42 months after surgical treatment. To the authors' knowledge, this is the first report of a carcinoid of the common bile duct as studied by immunohistochemistry. When six choledochal carcinoids were reviewed, the following characteristics were observed: in none of the cases were endocrine symptoms present; women were affected more frequently than men; the carcinoids occurred in younger patients than did adenocarcinomas; metastases were present in half of the patients; and, as a group, carcinoids seemed to have a better prognosis than adenocarcinomas in this location.