123rc/medical_text huggingface dataset:
Detection of myocardial infarction in the presence of Wolff-Parkinson-White syndrome by QRST isoarea map in dogs. The possibility of detecting myocardial infarction (MI) in the presence of Wolff-Parkinson-White (WPW) syndrome by means of body surface QRST isoarea maps was studied in eight dogs. Eighty-seven body surface ECGs were recorded simultaneously. Recordings were taken during right atrial (RA) and right atrial and right ventricular (RA + RV) sequential pacing, which simulated WPW syndrome, during control periods and at 1-hour intervals for up to 5 hours after occlusion of the left anterior descending coronary artery. In ECGs during the RA drive, diagnostic findings of MI such as abnormal Q waves were observed but became obscure during the RA + RV drive. On the contrary, the QRST values over the anterior chest during both drives were positive soon after coronary occlusion, decreased gradually as time passed, and became abnormally negative after 5 hours. The QRST isoarea maps during RA and RA + RV pacing showed quite similar patterns and were highly correlated with each other throughout this study (r greater than 0.95). These findings demonstrate that localized abnormalities resulting from MI are evident in QRST isoarea maps even in the presence of preexcitation and fusion.
Hyperandrogenism in peripubertal girls. Androgens arise from either adrenal or ovarian secretion or by peripheral conversion of secreted precursors. The adrenals and ovaries normally contribute about equally to testosterone and AD production. DHAS is the major adrenal 17-KS. Testosterone is the major circulating form of androgen. More than 96% of plasma testosterone is bound to SHBG; the free testosterone seems to be the bioavailable fraction. Hyperandrogenism must be considered in any girl with premature or excessive development of public hair or acne, menstrual irregularity (whether it be oligo-amenorrhea or dysfunctional uterine bleeding), or obesity. The most common cause of premature public hair development (pubarche) is premature adrenarche. The most common cause of hyperandrogenism presenting in a teenage girl is polycystic ovary syndrome. However, the differential diagnosis includes "exaggerated adrenarche," late-onset congenital adrenal hyperplasia, virilizing tumors, Cushing's syndrome, hyperprolactinemia, acromegaly, and abnormalities of androgen action or of metabolism. The plasma free testosterone is a more sensitive indicator of hyperandrogenism than is the total testosterone concentration. The pattern of response of plasma free testosterone, DHAS, and cortisol to dex-suppression testing is diagnostic of the source of androgen excess. Most hyperandrogenic adolescents will be found to have PCOS. The treatment is chosen according to particular symptoms, such as menstrual irregularity, hirsutism, or obesity.
Stages of T-cell receptor protein expression in T-cell acute lymphoblastic leukemia. In this study five monoclonal antibodies (MoAbs) to T-cell receptor (TCR) proteins (WT31, alpha F1, beta F1, TCR delta-1 and delta TCS-1) were used to identify discrete maturative stages in 40 cases of T-cell acute lymphoblastic leukemia (T-ALL). These MoAbs reacted exclusively with CD3+ T cells and did not label B-lineage and myeloid cells. In 17 of the 40 T-ALL cases studied the leukemic blasts lacked membrane and cytoplasmic TCR chains (group I). In 12 cases cells did not have membrane CD3/TCR but expressed cytoplasmic TCR proteins heterogenously: nine cases had cytoplasmic TCR beta chains (beta F1+, alpha F1-; group II), one case had cytoplasmic TCR alpha chains (alpha F1+, beta F1-; group III), and two cases were labeled by both alpha F1 and beta F1 MoAbs (group IV). The remaining 11 cases were mCD3+: nine were TCR alpha beta+ (group Va) and two exhibited TCR gamma delta (TCR delta-1+, delta TCS-1+; group Vb). The analysis of the TCR beta, -gamma, and -delta gene configurations in 23 of the 40 T-ALLs showed that: (1) the lack of TCR protein expression was due to the lack of TCR gene rearrangements only in one of nine cases; (2) five of five TCR beta+, TCR alpha- cases studied had germline TCR alpha genes (ie, no detectable TCR delta gene deletions); (3) seven of eight cases with TCR delta gene deletions expressed TCR alpha proteins, whereas in 12 of 20 of the T-ALLs with TCR beta gene rearrangements the synthesis of the corresponding protein occurred; only 2 of 16 cases with rearranged TCR delta genes expressed TCR delta chains. The T-ALL categories identified with anti-TCR MoAbs did not have additional characteristic phenotypic patterns and may correspond to the normal stages of T-cell development more precisely than those defined by other differentiation antigens.
Ubiquitin immunoreactivity in kuru plaques in Creutzfeldt-Jakob disease. Cerebellar kuru plaques in 2 cases of Creutzfeldt-Jakob disease were studied immunohistochemically. Similar to cerebellar senile plaques in Alzheimer's disease, many kuru plaques contained ubiquitin-positive, tau-negative small granular elements, presumably representing dystrophic neurites. Our results suggest that similar mechanisms are involved in neuritic changes in cerebellar plaques in Creutzfeldt-Jakob and Alzheimer's diseases despite differences of amyloid proteins in the plaques.
Enalapril and renal injury in spontaneously hypertensive rats. Rats of the spontaneously hypertensive strain develop kidney damage that resembles the nephropathy seen in some cases of human essential hypertension. Previous studies with a triple drug antihypertensive regimen indicated that proteinuria and glomerular histopathology in spontaneously hypertensive rats might develop despite long-term effective control of systemic blood pressure. To investigate further the relation between hypertension and kidney disease, a group of spontaneously hypertensive rats were treated with enalapril at 15 weeks of age. Blood pressure, protein excretion, and kidney function were measured in those rats at regular intervals during the next year and a half and were compared with untreated spontaneously hypertensive rats and the normotensive Wistar-Kyoto parent strain. Kidney tissue samples from all three groups, collected at autopsy, were stained by immunohistochemical and conventional methods to assess the relative severity and nature of kidney damage. Although enalapril therapy was completely effective in controlling the blood pressure of spontaneously hypertensive rats, it only postponed the onset of kidney disease. Enalapril-treated spontaneously hypertensive rats eventually exhibited albuminuria as severe as that found in hypertensive rats. Kidney vessel pathology was completely prevented with enalapril, but the abnormal accumulation of mononuclear cells in tubulointerstitial and periglomerular sites was the same as in untreated spontaneously hypertensive rats. We have concluded that elevated protein excretion in rats of the spontaneously hypertensive rat strain is not a secondary consequence of systemic hypertension. Structural abnormalities of renal vessels also do not appear to contribute significantly to the pathogenesis of albuminuria in spontaneously hypertensive rats. Other explanations must be sought to account for the close link between spontaneous hypertension and kidney damage in this animal model. The clear dissociation of kidney disease from systemic hypertension exhibited by spontaneously hypertensive rats may also be relevant for human disease.
Brain retractor edema during induced hypotension: the effect of the rate of return of blood pressure. This study evaluated the hypothesis that the postoperative formation of cerebral edema may be influenced by the rate of blood pressure return after induced hypotension in a graded brain retractor injury. Nineteen cats underwent unilateral craniotomy, isoflurane-induced hypotension to a mean of 50 mm Hg, and application of a brain retractor at 20 mm Hg of pressure for 1 hour. Blood pressure was returned to normal either within 3 minutes or over 20 minutes. The degree of cerebral edema formation was determined by Evans blue dye and coronal magnetic resonance imaging. All animals showed extravasation of Evans blue dye in the retracted hemisphere that was most marked at the periphery of the retractor. T1 relaxation times were significantly prolonged in the retracted hemispheres of both the fast return and slow return groups (18.8% and 17.8%, respectively) and more so at the Evans blue sites (42.8% and 40.8%), although not so strikingly beneath the retractor itself (6.3% and 7.8%). T2 relaxation times were similarly prolonged but to approximately half the degree of the T1 times. In the nonretracted hemisphere, drug-induced hypotension alone did not result in significant acute cerebral edema or blood-brain barrier alteration. There was no significant difference between the fast and slow groups in Evans blue extravasation or magnetic resonance changes. Thus, in a retractor-induced brain injury, restoration of arterial pressure to normal either gradually or rapidly did not influence the degree or extent of edema formation.
Site and strand specificity of UVB mutagenesis in the SUP4-o gene of yeast [published erratum appears in Proc Natl Acad Sci U S A 1991 Mar 1;88(5):2035] DNA sequencing was used to characterize 208 mutations induced in the SUP4-o tRNA gene of the yeast Saccharomyces cerevisiae by UVB (285-320 nm) radiation. The results were compared to those for an analysis of 211 SUP4-o mutations induced by 254-nm UVC light. In each case, greater than 90% of the mutations were single base-pair changes but G.C----A.T transitions predominated and accounted for more of the mutations induced by UVB than UVC. Double substitutions, single base-pair deletions, and more complex events were also recovered. However, UVB induced 3-fold more tandem substitutions than UVC and nontandem double events were detected only after irradiation with UVC. Virtually all induced substitutions occurred at sites where the pyrimidine of the base pair was part of a dipyrimidine sequence. Although the site specificities were consistent with roles for cyclobutane dimers and pyrimidine-pyrimidone(6-4) lesions in mutation induction, preliminary photoreactivation data implicated cyclobutane dimers as the major form of premutational DNA damage for both agents. Intriguingly, there was a preference for both UVB- and UVC-induced mutations to occur at sites where the dipyrimidine was on the transcribed strand.
Doppler assessment of pulmonary artery pressure and extrapulmonary shunting in the acute phase of hyaline membrane disease. The natural history of pulmonary artery pressure and extrapulmonary shunting in acute hyaline membrane disease was studied by serial Doppler echocardiography in 57 preterm infants, 38 with, and 19 without, hyaline membrane disease. Pulmonary artery pressure was assessed non-invasively by its inverse relationship with the ratio of pulmonary artery Doppler time to peak velocity: right ventricular ejection time. The mean ratio was significantly lower in the infants with hyaline membrane disease. The mean ratio for each infant with hyaline membrane disease varied widely and did not correlate with criteria of maturity or severity of disease. Individual ratios correlated with arterial pH. Between 60-80 hours after birth, 14 of 18 infants with hyaline membrane disease (78%) and one of 19 without (5%) had patent ductus arteriosus. Left to right and bidirectional shunting at ductal and atrial level were common; pure right to left shunting was uncommon. The mean ratio seen with bidirectional shunting was significantly lower than that seen with left to right shunting. Ratios and patterns of extra pulmonary shunting were similar when the fractional inspired oxygen (FIO2) was greater than 0.9 compared with when it was less than 0.9. Pulmonary artery pressure is high during the acute phase of hyaline membrane disease but varies widely among infants. A few infants have extrapulmonary right to left shunting, and these infants are difficult to detect clinically.
Extrapyramidal features in advanced Down's syndrome: clinical evaluation and family history. Extrapyramidal, frontal release, and other neurological signs were studied in 54 demented and non-demented patients with Down's syndrome (DS). Fourteen patients were demented and five showed extrapyramidal signs, mainly of the rigid-hypokinetic spectrum and similar to Parkinsonian features in advanced Alzheimer's disease (AD). None of the non-demented patients had Parkinsonian signs. The mean age of the demented DS patients with extrapyramidal signs was significantly higher than that of the patients without. Frontal release signs were present in demented and non-demented patients. A questionnaire showed no increase in either the proportion of early- or senile-onset dementia or Parkinsonism among first- and second-degree relatives of DS patients. Parkinsonian signs appear to be present at a lower frequency in DS than in advanced AD. A speculative hypothesis about a gene dosage effect of Cu/Zn-superoxide dismutase in preventing toxic radical formation in the substantia nigra of DS patients is presented.
Resuscitation of patients with cardiac arrest by ambulance staff with extended training in West Yorkshire OBJECTIVE--To investigate the results of resuscitation of patients with cardiac arrest by ambulance staff with extended training in West Yorkshire. DESIGN--Study of all such attempts at resuscitation over 32 months, based on the standard report form for each call made by the ambulance staff and the electrocardiogram that showed the initial rhythm in each patient. SETTING--Area covered by West Yorkshire ambulance service. SUBJECTS--1196 Patients with cardiac arrests attended by 29 ambulance staff with extended training. MAIN OUTCOME MEASURE--Result of resuscitation. RESULTS--The initial rhythm was asystole or electromechanical dissociation in 740 patients and ventricular fibrillation in 456 patients; overall 65 patients survived to be discharged from hospital. Sixty four of the 456 patients in whom ventricular fibrillation was the initial rhythm recorded, and 46 in whom ventricular fibrillation persisted after the ambulance staff arrived, survived. Only one of the 740 patients who initially had asystole or electromechanical dissociation survived. Factors associated with a greater chance of ventricular fibrillation occurring were: age less than 71, the arrest being witnessed by a bystander, resuscitation by a bystander, the arrest occurring in a public place, and a response time by the ambulance staff of less than six minutes. For patients found in ventricular fibrillation a shorter response time was associated with improved survival but resuscitation by a bystander was not. Additional skills learnt during extended training were used for 51 of the 65 patients who survived. CONCLUSIONS--Ambulance staff with extended training can save the lives of patients with cardiac arrest due to fibrillation, though asystole and electromechanical dissociation have a poor prognosis and should perhaps receive little attention during extended training.
Inadvertent clavicular fractures caused by "chiropractic" manipulations in an infant: an unusual form of pseudoabuse. A nine-month-old child was found unresponsive in his crib, five hours after his last feeding. At autopsy, there were no external or internal signs of abuse or neglect, and a few visceral pleural and epicardial petechiae were consistent with the sudden infant death syndrome (SIDS). However, postmortem total body radiographs revealed healing, symmetrical clavicular fractures and a healing left medial humeral epicondyle fracture. The parents had no explanation for these injuries and denied causing any harm to the child. The location and nature of the fractures strongly suggested abusive origin, and the case was reported to the police and the district attorney's office as child abuse. During the investigation, information from the parents indicated that the child had undergone "chiropractic" manipulations by an unlicensed therapist, between three and four weeks prior to death, to correct supposed "shoulder dislocations." This time interval correlated with the histologic age of the injuries, and the history explained their unusual bilateral location and appearance. The parents were exonerated of abuse charges, and the death was ascribed to SIDS.
Monomorphic adenomas of the major salivary glands: clinicopathological study of 44 cases. We report 44 cases of monomorphic adenoma (MA) of the major salivary glands observed during the years 1979-1989. All of these tumours were reviewed and classified on the basis of the World Health Organisation (WHO) criteria. Histological type, site, sex and age were considered. 34 cases of adenolymphoma were observed, all of them located in the parotid glands; 10 MA without lymphoid stroma were located in both parotid and submandibular glands. Distinctive histological and clinico-pathological features of the latter group of tumours are discussed, as well as the diagnostic criteria in distinguishing these tumours from pleomorphic adenoma and adenoid-cystic carcinoma.
Hilger facial nerve stimulator: a 25-year update. Percutaneous nerve excitability testing using the Hilger facial nerve stimulator was introduced about 25 years ago. The test is reliable, easy to use, and inexpensive; it continues to be the most frequently used method for predicting prognosis of facial nerve disorders. Between 1966 and 1974, we recorded 10,243 nerve excitability tests on 865 patients with a mean of 3.29 tests for each peripheral branch and 3.43 for the trunk. Using a multiple regression model, we determined the effect on nerve stimulation values of age, sex, race, diabetes, hypertension, partial or complete clinical paralysis, diagnosis of herpes zoster, year of testing, and eventual facial paralysis recovery profile. We discuss statistical reliability, provide a table of interpretive results, and offer "tips and traps" invaluable to the practitioner. A prospective study of 25 patients with residual facial paralysis was evaluated by two separate otolaryngologists to determine intertester reliability.
Cryoprobe as a "handle" for resection of metastatic liver tumors. Resection of metastatic liver tumors can be a difficult and risky procedure. Using a cryoprobe as a "handle" can greatly facilitate resection by providing a taut surface for transection and improving visualization of ductal and vascular structures. In addition, this technique may decrease the risk of contaminating surrounding tissues with cancer cells, and may inhibit tumor recurrence within the margins of resection.
Cardiac arrest during hip arthroplasty with a cemented long-stem component. A report of seven cases. Seven patients had a cardiac arrest during hip arthroplasty with a cemented long-stem femoral component. Four patients died in the operating room, and three patients were successfully resuscitated. When the three survivors were eventually discharged from the hospital, they had no known permanent cardiac, pulmonary, or neurological sequelae. Factors that were common to all of the patients were advanced age, osteoporotic bone, a previously undisturbed intramedullary canal, and use of a long-stem femoral component and several batches of methylmethacrylate. Hip arthroplasty with a long-stem femoral component is associated with substantial risk in these patients. Excessive pressurization of cement should be avoided, and invasive hemodynamic monitoring should be used when the described conditions are present.
Incorporation of 12-methoxydodecanoate into the human immunodeficiency virus 1 gag polyprotein precursor inhibits its proteolytic processing and virus production in a chronically infected human lymphoid cell line. Covalent linkage of myristate (tetradecanoate; 14:0) to the NH2-terminal glycine residue of the human immunodeficiency virus 1 (HIV-1) 55-kDa gag polyprotein precursor (Pr55gag) is necessary for its proteolytic processing and viral assembly. We have shown recently that several analogs of myristate in which a methylene group is replaced by a single oxygen or sulfur atom are substrates for Saccharomyces cerevisiae and mammalian myristoyl-CoA:protein N-myristoyltransferase (EC 2.3.1.97; NMT) despite their reduced hydrophobicity. Some inhibit HIV-1 replication in acutely infected CD4+H9 cells without accompanying cellular toxicity. To examine the mechanism of their antiviral effects, we performed labeling studies with two analogs, 12-methoxydodecanoate (13-oxamyristate; 13-OxaMyr) and 5-octyloxypentanoate (6-oxamyristate; 6-OxaMyr), the former being much more effective than the latter in blocking virus production. [3H]Myristate and [3H]13-OxaMyr were incorporated into Pr55gag with comparable efficiency when it was coexpressed with S. cerevisiae NMT in Escherichia coli. [3H]6-OxaMyr was not incorporated, even though its substrate properties in vitro were similar to those of 13-OxaMyr and myristate. [3H]13-OxaMyr, but not [3H]6-OxaMyr, was also efficiently incorporated into HIV-1 Pr55gag and nef (negative factor) in chronically infected H9 cells. Analog incorporation produced a redistribution of Pr55gag from membrane to cytosolic fractions and markedly decreased its proteolytic processing by viral protease. 13-OxaMyr and 3'-azido-3'-deoxythymidine (AZT) act synergistically to reduce virus production in acutely infected H9 cells. Unlike AZT, the analog is able to inhibit virus production (up to 70%) in chronically infected H9 cells. Moreover, the inhibitory effect lasts 6-8 days. These results suggest that (i) its mechanism of action is distinct from that of AZT and involves a late step in virus assembly; (ii) the analog may allow reduction in the dose of AZT required to affect viral replication; and (iii) combinations of analog and HIV-1 protease inhibitors may have synergistic effects on the processing of Pr55gag.
Factors affecting survival in total artificial heart recipients before transplantation. To identify factors affecting the successful bridge to transplantation, experience with 32 recipients of the Jarvik-7 artificial heart was reviewed. Between patients with and without a successful bridge, there were no significant differences in preoperative hepatorenal function or postoperative hemodynamics, but there were significant differences in body size. When recipients were divided according to body surface areas of less than or greater than 1.8 m2, the smaller patients more frequently developed respirator dependence (73% vs. 18%, p less than 0.01), renal failure (53% vs. 18%, p less than 0.05), and hepatic failure and sepsis, resulting in less frequent qualification for transplantation (20% vs. 65%, p less than 0.05). There were no successful bridge operations in seven patients with body surface areas of less than 1.7 m2, and only one success in nine patients who were less than 170 cm in height, despite use of a smaller stroke volume model. The smaller patients had poorer ventricular filling, which was largely compensated for by the drive controls set for significantly longer diastole and higher vacuum, resulting in similar hemodynamics between the groups. The results suggest that device fitting as manifested by body size is an important factor affecting major organ recovery and subsequent transplantation in recipients of the Jarvik-7 artificial heart. A paracorporeal device may be advisable for patients with body surface areas of less than 1.8 m2 or who were less than 175 cm in height until an even smaller model with a better fit in the thorax becomes available.