shukoor65/lab-rag-model huggingface dataset:
Amphetamine promotes recovery from sensory-motor integration deficit after thrombotic infarction of the primary somatosensory rat cortex. The present studies were undertaken to examine 1) whether d-amphetamine sulfate administered to rats well after thrombotic infarction of the vibrissal cortical barrel-field within the primary somatosensory cortex affected the rate and completeness of behavioral recovery and 2) whether a dose-response relation exists between d-amphetamine sulfate dose and recovery of function. In a learning task requiring sensory-motor integration, 41 rats were trained to perform a motor response in a T-maze consequent to the detection of a vibrissal deflection cue. Once training was complete, unilateral (n = 29) or sham (n = 12) infarction was produced by a noninvasive photochemical technique. After infarction, T-maze performance was assessed repeatedly in rats receiving 2 (n = 10) or 4 (n = 10) mg/kg d-amphetamine sulfate or saline (n = 9) 24 hours prior to testing on days 4, 6, 9, and 11. The sham-operated control rats received d-amphetamine sulfate (n = 7) or no injections (n = 5). All three infarcted groups displayed a reliable and sustained behavioral deficit in performance that was not present in the sham-operated control animals. Although the performance of each infarcted group improved over the testing sessions after the first injection, the amphetamine-treated groups improved at a faster rate than the saline-injected group. The results further demonstrated a dose-response effect, with the 4 mg/kg amphetamine group recovering to within preinfarction levels 6-8 days earlier than the 2 mg/kg amphetamine and saline-injected groups. Moreover, both amphetamine-treated groups recovered more completely than the saline-injected group. Quantification of the chronic infarct area revealed no differences among the amphetamine-treated and saline-injected groups. These data provide further evidence of the facilitatory effect of d-amphetamine sulfate on recovery from brain injury and extend this effect to the enhancement of recovery subsequent to thrombotic infarction of the primary somatosensory cortex.
The receptor for ciliary neurotrophic factor. Although neurotrophic factors were originally isolated on the basis of their ability to support the survival of neurons, these molecules are now thought to influence many aspects of the development and maintenance of the nervous system. Identifying the receptors for these neurotrophic factors should aid in identifying the cells on which these factors act and in understanding their precise mechanisms of action. A "tagged-ligand panning" procedure was used to clone a receptor for ciliary neurotrophic factor (CNTF). This receptor is expressed exclusively within the nervous system and skeletal muscle. The CNTF receptor has a structure unrelated to the receptors utilized by the nerve growth factor family of neurotrophic molecules, but instead is most homologous to the receptor for a cytokine, interleukin-6. This similarity suggestes that the CNTF receptor, like the interleukin-6 receptor, requires a second, signal-transducing component. In contrast to all known receptors, the CNTF receptor is anchored to cell membranes by a glycosyl-phosphatidylinositol linkage.
"Hemicrania continua": a clinical review. Hemicrania continua (HC) is a headache entity completely responsive to indomethacin. Since 1984, 18 cases have been described, 15 females and 3 males, i.e. a F:M ratio of 5.0. The finding of a female preponderance, like that in chronic paroxysmal hemicrania, is a new observation. HC is, in general, a unilateral headache in the sense that it sets in on one side and subsequently sticks to this side. In two cases, both sides might possibly be involved, when the pain was at its maximum. In another (somewhat dubious) case the headache was bilateral. The pain was continuous from the beginning in 8 of 18 cases (early stage ratio continuous: non-continuous = 0.8). Over time, the headache developed a continuous character in 16 of the 18 cases, producing a "continuous: non-continuous ratio" of 8:1. The intensity of pain generally was moderate and was not reported as excruciatingly severe by any patient. The autonomic involvement from a clinical point of view, was clearly less pronounced than that of other unilateral headaches, such as cluster headache and chronic paroxysmal hemicrania.
Thyrotropin-secreting pituitary adenomas: report of seven cases. Seven patients with hyperthyroidism due to a TSH-secreting pituitary macroadenoma have been observed of a total of 800 patients with pituitary tumors over a period of 15 yr. Serum TSH levels varied between 1.1-36.3 mU/L. The serum alpha-subunit level was low in 1 case, while in 4 other cases the concentration was elevated and varied between 3.7-7.8 micrograms/L. Serum TSH beta levels were normal in the 4 cases in which it was determined. Serum GH or PRL levels were elevated in 5 cases. In 1 patient the cosecretion of TSH, GH, and PRL was confirmed by immunocytochemical examination. Serum TSH and alpha-subunit responses to TRH, GnRH, CRF, GRF, dexamethasone, methimazole, T3, and bromocriptine administration were variable when studied. Serum TSH and alpha-subunit circadian rhythms were absent in 1 case and inverted in another. A serum alpha-subunit pulsatility without TSH pulses was observed in 1 patient. Five patients underwent transsphenoidal adenomectomy. Three of 4 patients operated on in our center were cured, but a recurrence of the adenoma was found in 1 of them after 5 yr. The fifth patient was not cured. Treatment with octreotide in 3 patients resulted in normalization of serum TSH, GH, and thyroid hormones levels. Cosecretion of PRL in 1 case and alpha-subunit in 2 cases was also inhibited. Partial tachyphylaxis occurred in 1 patient. In summary, heterogeneity in clinical presentation, hormonal expression, and therapeutic response appears to characterize these TSH-secreting adenomas.
Tinnitus: the hidden epidemic. A patient's perspective. The author describes his personal experience with tinnitus as well as various medical practitioners. He also discusses possible avenues for tinnitus research and suggests educational efforts that otolaryngology organizations might initiate.
Acute regional cerebral blood flow changes caused by severe head injuries. To evaluate the changes in cerebral blood flow (CBF) that occur immediately after head injury and the effects of different posttraumatic lesions on CBF, 61 CBF studies were obtained using the xenon-computerized tomography method in 32 severely head-injured adults (Glasgow Coma Scale score (GCS) less than or equal to 7). The measurements were made within 7 days after injury, 43% in the first 24 hours. During the 1st day, patients with an initial GCS score of 3 or 4 and no surgical mass had significantly lower flows than did those with a higher GCS score or mass lesions (p less than 0.05): in the first 1 to 4 hours, those without surgical mass lesions had a mean CBF of 27 cc/100 gm/min, which rose to 44 cc/100 gm/min by 24 hours. Patients without surgical mass lesions who died tended to have a lower global CBF than did those with better outcomes. Mass lesions were associated with a high global CBF and bihemispheric contusions with the lowest flows. By 24 hours after injury, global blood flow increased in groups that originally had low flows and decreased in those with very high initial flows, such that by 36 to 48 hours, most patients had CBF values between 32 and 55 cc/100 gm/min. Lobar, basal ganglion, and brain-stem blood flow values frequently differed by 25% or more from global averages. Brain-stem CBF varied the most but did not correlate with clinical signs of brain-stem dysfunction. Double studies were performed at two different pCO2 values in 10 patients with various posttraumatic lesions, and the CO2 vasoresponsivity was calculated. Abnormal CO2 vasoresponsivity was found with acute subdural hematomas and defuse cerebral swelling but not with epidural hematomas. In patients without surgical mass lesions, the findings suggest that CBF in the first few hours after injury is often low, followed by a hyperemic phase that peaks at 24 hours. Global CBF values vary widely depending on the type of traumatic brain injury, and brain-stem flow is often not accurately reflected by global CBF values. These findings underscore the need to define regional CBF abnormalities in victims of severe head injury if treatment is intended to prevent regional ischemia.
Observer variability of Osler's maneuver in detection of pseudohypertension. Pseudohypertension in the elderly occurs when blood pressure is overestimated because of inelastic, sclerotic arteries. Osler's maneuver (OM), the palpability of a pulseless artery, is recommended as a non-invasive test to detect pseudohypertension, despite limited data concerning its reproducibility. We assessed the maximum achievable inter-and intra-observer agreement of OM among 6 examiners: cardiologists, geriatricians and general internists. Each examiner performed OM twice on 65 elderly hypertensive men attending the general medicine and geriatric clinics. The inter-observer agreement for brachial and radial examinations was 79 and 70%, while intra-observer agreement was 82 and 75%, respectively. After adjusting for chance agreement the kappa values for inter-observer agreement for brachial and radial arteries were 0.38 (95% confidence interval (CI): 0.21-0.55) and 0.37 (0.28-0.46), respectively. Similarly, the kappa values for intra-observer agreement were 0.45 (95% CI: 0.35-0.55) and 0.49 (0.39-0.59). Kappa values never exceeded 0.6 in any time period, suggesting no training effect. OM cannot be recommended as a screening test for pseudohypertension given this low inter- and intra-observer agreement.
Future applications of electronic thermography. The dental literature does not yet indicate the full range of facial thermographic findings in health and disease. Thermography is not useful in assessing some common dental problems, such as periapical granuloma. Promising reports, however, support its use in the diagnosis of neuralgias and atypical odontalgia, TMJ, nerve damage and repair after oral surgery, and in evaluating local dental anesthesia. Unfortunately, few if any of these studies were properly designed or conducted, limiting current attempts to define the value of thermography in dentistry. Until this situation resolves, ET of the face, for use in dentistry, can only be considered an investigational procedure. More research will clarify the precise contribution of thermography to dental problems.
Percutaneous transluminal angioplasty involving internal mammary artery grafts. With the increasing use of the internal mammary artery as the conduit of choice in coronary bypass surgery, it is anticipated that an expanding patient population will have stenosis, usually at the site of internal mammary-to-coronary artery anastomosis. In our series 31 patients underwent dilatation at either the site of anastomosis (24), the native coronary artery beyond the anastomosis (4), or both (3) with no mortality, myocardial infarction, or need for emergency coronary artery bypass surgery. Angiographic and clinical success was achieved in 28 patients (90%). There were two internal mammary artery dissections with both patients requiring elective coronary bypass surgery. Of the patients in whom dilatation was successful, 22 (79%) have been followed for longer than 6 months and 19 (86%) have had sustained functional improvement at a mean of 35 months after angioplasty. One patient is to undergo repeat coronary bypass surgery. No patient has had a myocardial infarction or died during follow-up. Although percutaneous transluminal coronary angioplasty of the internal mammary artery has inherent difficulties because of the anatomic characteristics of the vessel, it can be performed with a high degree of primary success and a low incidence of complications and can provide long-term clinical improvement.
Acute gastrointestinal hemorrhage detected by selective scintigraphic angiography. Intra-arterial 99mTc colloid scintigraphy may have greater sensitivity than either standard intravenous scintigraphy or selective arteriography in detecting gastrointestinal bleeding. Ten millicuries of 99mTc colloid were administered directly into the superior and inferior mesenteric arteries (SMA and IMA) of patients who had undergone selective arterial catheterization for the evaluation of gastrointestinal bleeding. In one patient, 99mTc-albumin colloid was administered directly into the IMA and identified diverticular bleeding. The bleeding had been occult to prior contrast arteriography and refractory to selective intra-arterial Pitressin therapy. In a second patient who had undergone three negative provocative angiograms, selective SMA injection of 99mTc-sulfur colloid identified occult mesenteric varices secondary to portal hypertension. Selective intra-arterial scintigraphy should be valuable in detecting intestinal bleeding occult to conventional studies. This will help in directing further therapy and diagnostic evaluation.
Reconstruction of the medial half of the lower eyelid using a "switch" split-lid procedure. Reconstruction of the medial half of the lower eyelid has one major disadvantage: It produces a scar at right angles to the eyelid rim. In contrast, use of a "switch" split-lid procedure avoids this inconvenience. The lateral half of the lower eyelid is split in two lamellae. The inner layer is transferred medially, and the resulting defect is closed with a buccal graft. The outer layer is drawn laterally to cover the raw surface of the mucosal pedicle and graft. The surplus of skin over the lateral canthal area is removed. This procedure, which so far has been used in three patients, promises to be a useful alternative for reconstruction of the medial half, but not more, of the lower eyelid.
Effect of vasoconstriction on longitudinal distribution of pulmonary vascular pressure and volume. We used an improved version of the low-viscosity bolus method to evaluate longitudinal (arterial-to-venous) differences in the sensitivity of the dog lung lobe vasculature to selected vasoconstrictor stimuli, including hypoxia, and serotonin, histamine, and norepinephrine infusions. This method revealed a bimodal distribution of local vascular resistance vs. cumulative vascular volume under the zone 3 conditions studied. Our interpretation of the two modes of relatively high resistance is that they correspond to high resistance per unit volume segments of the arteries and veins upstream and downstream from the relatively low resistance per unit volume capillary bed. Thus an increase in the height of the upstream and downstream modes of the resistance distribution suggests constriction in small arteries and veins, respectively. Horizontal displacement of the modes along the cumulative volume axis suggests changes in the distribution of volume among the arteries, veins, and capillary bed. By use of these criteria, the results are consistent with the concept that each of the vasoconstrictor stimuli studied had a different longitudinal response pattern. Hypoxia constricted mainly small arteries, whereas serotonin constricted small and large arteries. Histamine constricted large and small veins, and norepinephrine constricted large and small veins and arteries.
Successful balloon aortic valvuloplasty in a patient with mitral valve endocarditis. A critically-ill 73-year-old man was admitted with simultaneous mitral valve endocarditis and aortic stenosis. Balloon aortic valvuloplasty was performed successfully and without complications and was followed by prompt clinical improvement. Balloon aortic valvuloplasty should be considered in patients with aortic stenosis and nonaortic valve endocarditis.
Expression and distribution of atrial natriuretic peptide in human hypertrophic ventricle of hypertensive hearts and hearts with hypertrophic cardiomyopathy. To investigate the ventricular expression of atrial natriuretic peptide (ANP) in human hypertrophic hearts, we conducted an immunohistochemical study of 130 endomyocardial biopsy specimens obtained from the right side of the ventricular septum (RVB), left ventricular free wall (LVB), or both from a total of 80 patients: 44 patients with hypertrophic cardiomyopathy (HCM), 14 with apical hypertrophic cardiomyopathy (APH), 13 with hypertensive hearts (HHD), and nine without hypertrophy (controls). No patients had apparent congestive heart failure. ANP was not seen in ventricular myocytes in controls but was identified in biopsy specimens of hypertrophic hearts, and its distribution was characteristic in each hypertrophic group: 15 RVB (37%) and two LVB (7%) of the HCM group, one RVB (7%) and two LVB (18%) of the APH group, and zero RVB (0%) and five LVB (46%) of the HHD group. Clinical data (including echocardiographic, hemodynamic, and angiographic data) were not directly related to ventricular ANP expression in HCM, APH, or HHD with one exception. In HHD patients, LVB specimens with ANP showed greater ventricular wall thickness than LVB specimens without ANP. According to histological data, however, the ANP-present RVB specimens of HCM or ANP-present LVB specimens of HHD had greater myocyte size than did the ANP-absent specimens. In addition, in HCM patients, the ANP-present RVB specimens showed more severe fibrosis and myofiber disarray than did the ANP-absent specimens. We conclude that a failing state and hemodynamic overload are not likely to be indispensable for ANP expression in human hypertrophic ventricles and that ventricular ANP expression occurs as a response to disease-specific changes: hemodynamic overload in HHD and histological changes such as myocardial fiber disarray, hypertrophy of myocytes, and fibrosis in HCM, which may reflect the characteristic distribution of intraventricular ANP.
Management of childhood cholesteatoma. We report a retrospective study of 54 children with 57 involved ears who underwent surgery for cholesteatoma before their sixteenth birthdays. The majority of these underwent open cavity operations (modified radical mastoidectomy, radical mastoidectomy or atticotomy). The incidence of residual disease was only 6 per cent and overall 70 per cent of ears have been free of chronic discharge. The post-operative hearing thresholds were disappointingly low, though overall no worse than those recorded before surgery. The mean post-operative hearing level for the group was 39 dB and the mean air-bone gap was 29 dB. Open cavity surgery is the method of choice for childhood cholesteatoma, mainly because of the low incidence of residual disease.
Cytologic manifestations of ballistic injury. The adherent residue from 60 projectiles in 38 consecutive gunshot wound deaths was analyzed by cytologic technique to determine whether a bullet, while passing through the body or intermediate target, retains tissue and other trace evidence. The projectiles, which were recovered from both the body and shooting area, contained microscopically recognizable cellular and inert material in all cases. Direct ballistic trauma could be documented in several tissue types, most notably in muscular tissue. Progressive damage to skeletal and cardiac muscle was seen in multiple preparations. This ranged from partial separation of the fascicles to cytoplasmic homogenization and nuclear rupture. Except in cases of severe ballistic trauma, skeletal and cardiac muscle could be distinguished on the preparations. In addition to neural tissue, projectiles traversing the central nervous system (CNS) contained elongated fragments of intact microvascular structures, sheets of cerebral covering cells, and connective tissue from the scalp. The vascular structures present in CNS preparations may clarify some of the clinical findings in victims of gunshot wounds and elucidate possible pathophysiologic mechanisms in craniocerebral projectile injuries.
Laboratory differences in cervical cytology. This prospective study was designed to determine if there is a difference in reporting endocervical cells in Papanicolaou smears among laboratories used by an urban, academic family practice. A review of the literature found no studies comparing Papanicolaou smear results among laboratories with respect to the presence of endocervical cells. In this study, three laboratories evaluated a total of 140 Papanicolaou smears from women aged 16 to 83 (mean = 33.8) for endocervical cells. The presence of endocervical cells was reported for 88 smears (62.9%) ranging from 42/83 (50.6%) to 21/23 (91.3%) among laboratories. Results of an analysis of variance revealed a statistically significant difference in the frequency of reporting endocervical cells (p less than .001) among the laboratories. Analysis of covariance controlling for effects of several factors known to influence the outcome of Papanicolaou smears (age, days since last menstrual period, method used to obtain smear, and experience of clinician obtaining smear) failed to explain this difference.
Parent-child concordance in multiple sclerosis. It is now recognized that susceptibility to multiple sclerosis (MS) is determined in part by genetic factors. The gene loci influencing MS susceptibility are largely unidentified. In an attempt to better understand the mode of transmission, parent-child concordance for MS was studied in two large, population-based MS clinic populations. Among 75 parent-child pairs concordant for MS, we found 40 mother-daughter pairs, 13 mother-son pairs, 21 father-daughter pairs, and 1 father-son pair. Controlling for the known female preponderance in MS, the data show a paucity of father-son pairs. These data have implications for understanding the mechanisms of inheritance for MS susceptibility as well as for risk counseling in families of patients.
Empiric therapy with amphotericin B in febrile granulocytopenic patients. The early diagnosis of invasive fungal infection in granulocytopenic patients remains unreliable. Granulocytopenic patients who are persistently or recurrently febrile despite therapy with appropriate antibacterial agents are at high risk for the development of such infection. Two randomized clinical trials demonstrated that the empiric administration of amphotericin B to persistently or recurrently febrile granulocytopenic patients decreased the frequency, morbidity, and mortality of invasive fungal infection; these effects were especially marked in profoundly granulocytopenic patients who were not receiving antifungal prophylaxis. Current studies continue to indicate that prompt empiric administration of amphotericin B to persistently or recurrently febrile granulocytopenic patients ensures earlier treatment of deep mycoses. The roles of newer antifungal triazole compounds and of liposomal and lipid complexes of amphotericin B in empiric antifungal therapy must be investigated further in thoughtfully designed, randomized clinical trials.