123rc/medical_text huggingface dataset:
Delayed central nervous system myelination in the sudden infant death syndrome. This study was designed to assess whether development of the central nervous system (CNS) is delayed in victims of the sudden infant death syndrome (SIDS). We selected the parameter of myelination because it is a continuously changing and readily accessible marker of CNS development in the SIDS age-range. We assessed myelination blindly in 61 SIDS and 89 autopsy controls. In 62 sites the degree of myelination was visually graded in myelin-stained histological sections on an ordinal scale of 0-4 using the inferior cerebellar peduncle as an internal standard of degree 3. Cases were stratified by postconceptional age at death and SIDS and controls were compared with respect to myelin degree at each site. Significantly delayed myelination (p less than 0.05) occurred in the SIDS group in 25 of the 62 sites examined. Hypomyelination affected fiber systems in which myelination is initiated before or after birth and which myelinate with different tempos and preferentially affect pyramidal and cerebellar (somatomotor) and prefrontal-temporal-limbic (visceromotor) systems. Hypomyelination was not associated with individual clinicopathologic variables in the SIDS group. Somatic growth and brain weight were significantly greater in SIDS than controls. Therefore, we suggest that SIDS is associated with a developmental CNS disorder. Although delayed CNS myelination most likely shares a common antecedent with sudden death and is not its cause, the role of somato- and viscero-motor systems in central cardiorespiratory control and arousal warrants further analysis in SIDS.
Long term effects of gastrocystoplasty in rats. Twenty prepubescent rats underwent microsurgical gastrocystoplasty by a technique which is described. An equal number of control rats had their bladders opened and closed. Rats were sacrificed at 16 to 18 months postoperatively. There were no differences in final weight, serum electrolytes, or renal function between the two groups. Prominent histopathologic changes of the bladder occurred in the gastrocystoplasty group. These changes included papillomas present in five of the 15 rats surviving long term. No significant changes occurred in the bladders of the control group of rats. Possible etiologies and the significance of the rats. Possible etiologies and the significance of the gastrocystoplasty related lesions are discussed.
Human growth hormone and insulin-like growth factor-1 enhance the proliferation of human leukemic blasts. As the number of long-term survivors of childhood leukemia increases, growth retardation has emerged as a significant complication. Treatment of these children with growth hormone (GH) has been suggested and sporadically implemented. We, therefore, studied the effect of human GH (hGH) and its by-product insulin-like growth factor-1 (IGF-1) on the growth of leukemic cells in vitro. Under serum-free conditions hGH and IGF-1 induced a significant dose-dependent proliferative effect on promyelocytic leukemia (HL60) and Burkitt's lymphoma (Daudi) cell lines. Anti-hGH antibodies negated the stimulatory effect of hGH and anti-IGF-1 serum abrogated the growth-promoting effect enhanced by IGF-1. Similar statistically significant stimulatory properties were found when freshly obtained marrow cells from four of five acute lymphoblastic leukemia (ALL) of childhood and four acute myelogenous leukemia (AML) patients were studied in ALL and AML blast-cell clonogenic assays. ALL colonies increased numerically by 72% (P less than .025) and AML colonies by 92% (P less than .01) in the presence of hGH at concentrations of 2.5 x 10(2) and 3.0 x 10(2) ng/mL, respectively. IGF-1 stimulated ALL and AML blast-colony growth at concentrations ranging from 0.05 to 0.5 ng/mL by up to 105% (P less than .025) and 65% (P less than .03), respectively. Our in vitro data suggest that circulating hGH and IGF-1 may promote leukemic blast cell replication in vivo, and the supplemental administration of hGH to leukemia patients in remission must be carefully monitored for early relapse.
Median nerve somatosensory evoked potentials and the Glasgow Coma Scale as predictors of outcome in comatose patients with head injuries. Median nerve somatosensory evoked potential (SSEP) grades and Glasgow Coma Scale (GSC) scores were obtained from 51 patients with head injuries within 1 week after the injury to determine the relationship of these scores, both individually and combined, to outcome scores obtained more than 6 months after the injury. SSEP grading was based on the presence or absence of the cortical evoked potential, the amplitude of the early cortically generated P22 wave form, and the conduction time through the brain (P/N13-N20 interpeak latency). SSEP responses from both sides of the brain were combined and graded from 1 to 6. The GCS was graded without the verbal component (maximum score, 10), because all patients were intubated. All patients were unresponsive to commands. Median SSEP grades correlated better with Glasgow Outcome Scale and Barthel Index scores (R = 0.57 and 0.64, respectively; P less than 0.00001) than GCS scores did (R = 0.35 and 0.37, respectively, P less than 0.00001), and combining SSEP grades and GCS scores did not improve the predictive power of the model (R = 0.57 and 0.64, respectively; P less than 0.00001). All SSEP Grade 1 patients (n = 13) either died or remained in a vegetative state. In contrast, all SSEP Grade 6 patients (n = 7) had a moderate disability or good recovery. This study demonstrates the prognostic value of early quantitative median nerve SSEP grading for patients with head injuries who are unresponsive to commands within 1 week after the injury.
Impairment of esophageal emptying with hiatal hernia. Concurrent videofluoroscopy and manometry were used to analyze esophageal emptying during barium swallows in 22 patients with axial hiatal hernias and in 14 volunteers. Subjects were divided into three groups: (a) volunteers with maximal phrenic ampullary length less than 2 cm (controls); (b) patients or volunteers with maximal ampullary/hiatal hernia length greater than or equal to 2 cm that reduced between swallows (reducing-hernia group); and (c) patients with hernias that did not reduce between swallows. Complete esophageal emptying without retrograde flow was achieved in 86% of test swallows in the controls, 66% in the reducing-hernia group, and 32% in the nonreducing-hernia group (P less than 0.05). Impaired emptying in the reducing-hernia group was attributable to "late retrograde flow," whereby barium squirted retrograde from the hernia during emptying. Impaired emptying in the nonreducing-hernia group was attributable to "early retrograde flow" that occurred immediately after LES relaxation. The nonreducing-hernia group also had longer acid clearance times than the controls (P less than 0.05). We conclude that gastroesophageal junction competence is severely impaired in patients with nonreducing hiatal hernias, suggesting a mechanism whereby this subgroup of hiatal hernia is involved in the pathogenesis of reflux disease.
Treatment of solitary arteriovenous fistulas. Four patients with a solitary arteriovenous fistula were treated by transvascular balloon embolization technique, which resulted in complete fistula closure in three patients and partial closure in one. There were two vertebral arteriovenous fistulas, one peroneal arteriovenous fistula, and one radial arteriovenous fistula. The first two fistulas were spontaneous, the other two were traumatic. The only partial occlusion of the peroneal fistula was, in our opinion, due to a technical failure, the balloon was inflated slightly proximal to the fistular orificium instead of in the orificium itself. There were no complications, and there was no morbidity. In our opinion transvascular balloon embolization technique is the treatment of choice for solitary arteriovenous fistulas.
Lung function and pulmonary regurgitation limit exercise capacity in postoperative tetralogy of Fallot. Fifty-five patients with repair of tetralogy of Fallot were evaluated with treadmill exercise, pulmonary function testing and rest two-dimensional and Doppler echocardiography to determine the relation among cardiopulmonary function, exercise capacity and ventricular arrhythmias. The mean age at repair was 8.1 +/- 2.1 years; age at the time of study ranged from 15 to 37 years (mean follow-up time after repair 18 +/- 5 years). Exercise duration was 92 +/- 17% of predicted. Maximal heart rate was 94 +/- 7% of predicted. No exercise test was stopped because of an arrhythmia. Thirty patients had oxygen consumption and ventilation measured during their final minute of exercise. Peak oxygen consumption was 31 +/- 8 ml/kg per min (86 +/- 18% of predicted). Twenty-five patients (45%) had low vital capacity at rest (less than 80% of predicted). Pulmonary regurgitation was identified in 42 (75%) of the patients and judged to be moderate in 10 (18%). Mild tricuspid valve regurgitation was identified in 64%. Doppler estimated right ventricular outflow gradient was greater than 15 mm Hg in 15% of the patients (mean gradient 24 mm Hg [range 16 to 56]). Age at repair, duration of follow-up and type of repair did not correlate with echocardiographic variables, ventilatory data, exercise performance or arrhythmias. Moderate pulmonary regurgitation was associated with increased right ventricular diastolic area and both were inversely related to exercise duration and vital capacity. Decreased breathing reserve during maximal exercise was associated with moderate pulmonary regurgitation and decreased vital capacity. The results indicate that exercise capacity in these patients is in general good; however, right ventricular volume loading and ventilatory dysfunction may produce exercise limitation.
Tumors of the shoulder girdle. Technique of resection and description of a surgical classification. Limb-sparing surgery is safe and reliable for most bone and soft-tissue tumors of the shoulder girdle. Eighty to ninety percent of patients with high-grade sarcomas of the shoulder can be safely treated by the various surgical techniques described. Attention must be paid to appropriate patient selection, preoperative staging, and planning. In addition, careful skeletal and muscular reconstruction of the surgical defect is necessary for a successful outcome. A new, universal, classification schemata (types I-VI) of shoulder girdle resections has been developed. This classification system is based on the bones resected, the status of the abductor mechanism, and the relationship to the glenohumeral joint. This system permits easy description and comparison of the various limb-sparing procedures performed.
Tyrosine kinase and control of cell proliferation. The usefulness of phosphotyrosine antibodies for the detection of physiologically regulated or deregulated tyrosine kinases is discussed in this report. This rather rare enzymatic activity is shared by receptors for some polypeptide growth factors and by the products of Class 1 oncogenes. The antibodies are able to detect proteins phosphorylated on tyrosine in fibroblasts stimulated with growth factors such as EGF and PDGF. The major phosphorylated protein species are the receptors themselves, which undergo phosphorylation only after the addition of the exogenous factor and only transiently. Phosphotyrosine antibodies were able to detect the products of the retroviral Class 1 oncogenes, which are endowed with deregulated tyrosine kinase activity. In fact, in these cases a constitutive phosphorylation of the relevant proteins was observed, which occurred continuously and independently of the presence or lack of exogenous ligands. A tyrosine kinase constitutively activated in human gastric carcinoma cells was detected by P-Tyr antibodies. This molecule has been characterized at the molecular level, and the mechanisms responsible for its enzymatic activation have been investigated. The question of whether the tyrosine kinase identified is responsible for the induction and the maintenance of the transformed phenotype in gastric carcinomas remains to be answered. It is reasonable to suggest that this might be the case by analogy with other situations such as Class 1 oncogenes activated by transduction by retroviruses, abnormal expression of EGF receptors, or deregulated activity of c-abl-encoded proteins in chronic myelogenous leukemia and acute lymphoblastic leukemia. Thus, the search for deregulated kinases by means of phosphotyrosine antibodies seems to be useful for identifying new activated oncogenes in clinical oncology.
Transfection of C6 glioma cells with connexin 43 cDNA: analysis of expression, intercellular coupling, and cell proliferation. C6 glioma cells express low levels of the gap junction protein connexin 43 and its mRNA and display very weak dye coupling. When implanted into the rat cerebrum, these cells quickly give rise to a large glioma. To investigate the role of gap junctions in the tumor characteristics of these cells, we have used Lipofectin-mediated transfection to introduce a full-length cDNA encoding connexin 43. Several transfected clones were obtained that exhibited various amounts of connexin 43 mRNA transcribed from the inserted cDNA. Immunocytochemical analysis revealed an increase in the amount of connexin 43 immunoreactivity in the transfected cells, being localized at areas of intercellular contact as well as in the cytoplasm. The level of dye coupling was also assessed and found to correlate with the amount of connexin 43 mRNA. When cell proliferation was followed over several days, cells expressing the transfected cDNA grew more slowly than non-transfected cells. These transfected cells will be useful in examining the role of gap junctions in tumorigenesis.
Retrovirus-induced spongiform myeloencephalopathy in mice: regional distribution of infected target cells and neuronal loss occurring in the absence of viral expression in neurons. The Cas-Br-E murine leukemia virus (MuLV) induces a spongiform myeloencephalopathy resulting in a progressive hindlimb paralysis. We have used in situ hybridization with a Cas-Br-E MuLV-specific probe to study viral expression in the central nervous system. Infected cells were concentrated in regions where spongiform lesions and gliosis are detected (lumbosacral spinal cord, brainstem, deep cerebellar regions), suggesting a causative link between the level of virus expression and the degree of pathological changes in this disease. However, viral expression was not in itself sufficient to cause disease, since significant viral expression was observed in regions that did not exhibit pathological changes (cerebellar cortex, hippocampus, corpus callosum, peripheral nervous system). In both diseased and nondiseased regions, endothelial and glial cells were identified as the main target cells. Neurons in diseased regions did not show viral expression. The regional distribution of the spongiform changes appears to be laid down very early following infection, since expression could be detected at 10 days postinfection in regions that become diseased. These results indicate that nonneuronal cells have distinct properties in various regions of the central nervous system and suggest an indirect mechanism of neuronal loss consequent to viral expression in nonneuronal cells.
131I treatment of thyroid papillary carcinoma in a patient with renal failure. Procedures for 131I ablation in renal failure are not known. In one patient receiving dialysis, detailed dosimetry and health safety aspects were obtained. The results showed insignificant contamination of equipment, but a surprisingly significant reduction in biologic half-life of 131I due to efficient dialysis extraction. The data indicate that 131I ablation can be done safely and easily during dialysis but that much higher 131I doses must be used to achieve equivalent results to those obtained in patients with normal renal function.
Transcranial stab wounds: morbidity and medicolegal awareness. In this series of eight patients with transcranial stab wounds, the importance of classifications of such wounds as a separate traumatic entity is stressed. The mechanisms of neuronal and vascular damage in these wounds are discussed and are found to be specific from other head injuries. Cerebral injury by stabbing is largely restricted to the wound tract. Frontal stabs (two cases) are accompanied by the least morbidity and mortality, while temporal stabs (four cases) are more commonly fatal. In transorbital stabs (two cases) carotid-cavernous fistulae resulted. Early recognition, administration of antitetanus serum and antibiotics, and debridement may minimize complications.
Remodeling of the rat right and left ventricles in experimental hypertension. Pathological left ventricular hypertrophy in renovascular hypertension is associated with the accumulation of fibrillar collagen within the extracellular space and around intramyocardial coronary arteries. Even though the angiotensin converting enzyme inhibitor captopril was previously found to attenuate this interstitial and perivascular fibrosis, the relative importance of arterial and ventricular systolic pressures versus circulating angiotensin II (AII) and aldosterone (AL) in promoting hypertrophy and collagen accumulation in renovascular hypertension is uncertain. By drawing on the in-parallel arrangement of the right and left ventricles, with respect to their coronary circulation, and the in-series mechanical alignment of the ventricles, with a pressure-overloaded left and a normotensive right ventricle, this study sought to address this uncertainty. Three models of experimental hypertension, each having a different circulating AII and AL profile, were examined and compared with their controls: renovascular hypertension, where both AII and AL are increased; infrarenal aorta banding, where AII and AL are normal; and a chronic infusion of AL, where AII is suppressed or normal and AL is increased. In renovascular hypertension, as well as with AL, we found a significant rise in the interstitial collagen volume fraction and perivascular collagen area of the pressure-overloaded, hypertrophied left ventricle as well as the normotensive, nonhypertrophied right ventricle. This remodeling was not seen in either ventricle with infrarenal aorta banding despite comparable systemic hypertension and left ventricular hypertrophy. Thus, in experimental arterial hypertension in the rat, myocyte and nonmyocyte compartments of the myocardium are under separate controls: myocyte hypertrophy is most closely related to ventricular loading while circulating AII and AL, acting alone or in concert with other humoral factors, regulate the accumulation of collagen within the right and left ventricles.
Safety of same-day sequential extracorporeal shock wave lithotripsy and dissolution of gallstones by methyl tert-butyl ether in dogs. Passage of stone fragments after extracorporeal shock wave lithotripsy (ESWL) of gallstones has resulted in biliary colic, duct obstruction, and pancreatitis in some patients. Rapid dissolution of these fragments with methyl tert-butyl ether (MTBE) may prevent such side effects and achieve complete clearance of gallstones within hours rather than several months to a year or longer. This study examines the safety of same-day ESWL fragmentation and MTBE dissolution of surgically implanted human gallstones in 15 dogs. The animals were randomly assigned to one of four treatment groups to assess MTBE absorption from the gallbladder and to observe hematology and chemistry profiles after 0, 400, and 1,200 shock waves from a lithotriptor followed by MTBE dissolution therapy. They were sacrificed either immediately after treatment (12 dogs) or 2 weeks later (3 dogs). The results demonstrated that although ESWL causes moderate trauma to the gallbladder, this did not result in increased MTBE absorption or histologic evidence of mucosal disruption. Blood profiles demonstrated an increase in only the level of aspartate aminotransferase. The three dogs that were sacrificed 2 weeks after the combined treatment had no residual evidence of gallbladder injury or remaining stone material. In all animals, severe injury occurred where shock waves passed through lung or air-filled colon. This study suggests that same-day sequential fragmentation of gallstones by ESWL followed by dissolution of stone fragments with use of MTBE may be associated with only mild to moderate and reversible gallbladder trauma and can rapidly achieve clearance of gallstones.
Management of acute uncomplicated urinary tract infection in adults. Acute uncomplicated UTI is one of the most common problems for which young women seek medical attention, and it accounts for considerable morbidity and health care costs. Acute cystitis is a superficial infection of the bladder mucosa, whereas pyelonephritis involves tissue invasion of the upper urinary tract. Localization tests suggest that as many as one third of episodes of acute cystitis are associated with silent upper tract involvement. Acute cystitis or pyelonephritis in the adult patient should be considered uncomplicated if the patient is not pregnant or elderly, if there has been no recent instrumentation or antimicrobial treatment, and if there are no known functional or anatomic abnormalities of the genitourinary tract. Most of these infections are caused by E. coli, which are susceptible to many oral antimicrobials. Because of the superficial nature of cystitis, single-dose and 3-day regimens have gained wide acceptance as the preferred methods of treatment. Review of the published data suggests that a 3-day regimen is more effective than a single-dose regimen for all antimicrobials tested. Regimens with trimethoprim-sulfamethoxazole appear to be more effective than those with beta-lactams, regardless of the duration. Acute pyelonephritis does not necessarily imply a complicated infection. Upper tract infection with highly virulent uropathogens in an otherwise healthy woman may be considered an uncomplicated infection. The optimal treatment duration for acute uncomplicated pyelonephritis has not been established, and 14-day regimens are often used. We prefer to use antimicrobials that attain high renal tissue levels, such as trimethoprim-sulfamethoxazole or quinolones, for pyelonephritis. Women with frequently recurring infections can be successfully managed by continuous prophylaxis, either daily or thrice-weekly, by postcoital prophylaxis, or, in compliant patients, by early self-administration of single-dose or 3-day therapy as soon as typical symptoms are noted. Our drug of choice for all these regimens is trimethoprim-sulfamethoxazole. Acute uncomplicated cystitis in adult men is very uncommon, but it is occasionally noted in homosexual men who practice insertive and intercourse or in heterosexual men whose partners have vaginal colonization with E. coli.
Mallory-Weiss syndrome after cardiopulmonary resuscitation. We report hematemesis from Mallory-Weiss tears after successful cardiopulmonary resuscitation (CPR). A computer search of the English language literature disclosed only 3 similar cases, and we review them. This complication of CPR may occur more frequently than recognized and should be prevented by careful technique.