123rc/medical_text huggingface dataset:
Growth hormone inhibits tumor metastasis. The effect of growth hormone on tumor growth and metabolism in the tumor-bearing host is unknown. This study was done to determine the effect of recombinant growth hormone on primary tumor growth, tumor metastasis, and carcass weight in tumor-bearing animals. Twenty-seven female Lobund/Wistar rats with subcutaneous prostate tumor implants (PA-III) were randomized to receive a standard protein diet (22.0% protein; 4.27 kcal/g) or an isocaloric, protein-depleted diet (0.03% protein; 4.27 kcal/g) ad libitum orally. One half of the animals in each group were randomized to receive daily injections of either recombinant growth hormone (1000 mU/kg/day intramuscularly) or placebo (saline) for 14 days. A significant increase in body weight was observed in growth hormone-treated animals without acceleration of primary tumor growth. Spontaneous pulmonary metastasis was inhibited significantly in animals in both dietary groups treated with growth hormone. Thus, growth hormone selectively supports host growth and inhibits pulmonary metastasis in this tumor-bearing animal model. The potential metabolic effects and clinical consequences of treating cancer patients with growth hormone is discussed.
Approach to the patient with genital ulcer disease. The three major diseases characterized by genital ulcers--genital herpes, syphilis, and chancroid--are common, with genital herpes being most common in industrialized countries and chancroid being most common in developing countries. One fourth to one half of patients with genital ulcers have no diagnosed cause for their illness despite diagnostic efforts. The bulk of these cases is probably constituted by one of the three diseases for which diagnostic tests are falsely negative. There is accumulating evidence that genital ulcers facilitate the transmission of human immunodeficiency virus (HIV), and they may also be markers of high-risk behavior for acquisition of HIV. Appropriate therapy of patients with genital ulcers (as well as their sexual partners) depends on accurate diagnosis. Patients with genital ulcers, particularly those with syphilis or chancroid, should be encouraged to undergo testing for HIV infection.
Intracranial pressure in African children with cerebral malaria Opening lumbar cerebrospinal fluid (CSF) pressure was measured with a paediatric spinal fluid manometer in 26 of 61 Kenyan children (mean age 39 months) with cerebral malaria. In all cases pressure was above normal (mean [SD]22.6 [7.4] cm CSF, range 10.5-36). Clinical features of our patients suggest that intracranial hypertension is important in the pathogenesis of cerebral malaria in children, especially as a cause of death. We suggest that raised intracranial pressure is secondary to increased cerebral blood volume. Lowering intracranial pressure may significantly reduce the mortality and morbidity of cerebral malaria. The potential risks and benefits of lumbar puncture should be considered carefully in patients with suspected cerebral malaria.
Studies of myocardial protection in the immature heart. I. Enhanced tolerance of immature versus adult myocardium to global ischemia with reference to metabolic differences. This study compares the metabolism and functional responses of adult and immature hearts to a standard ischemic insult. Ten adult dogs (25 to 27 kg) and 10 puppies (6 to 10 weeks old) underwent 45 minutes of aortic clamping on bypass. Preoperative and postoperative ventricular performance (Starling curves), biochemical factors, and water content were measured. Global ischemia in adults produced a 30% mortality rate (3/10) and low output syndrome in survivors (33% recovery of stroke work index). Conversely, all puppies survived and stroke work index returned to 85% of control, with less edema developing (0.4% versus 2% water gain, p less than 0.05). Puppies expended comparable glycogen stores but used more glutamate (15.4 versus 8.6 mumol/gm dry weight), produced more alanine (18.9 versus 6.4 mumol, p less than 0.05), succinate (19 versus 8.2 mumol, p less than 0.05), and malate (2.6 versus 0.15 mumol, p less than 0.05) during ischemia, and recovered better postischemic aerobic metabolism (410 versus 255 nmol tissue pyruvate, p less than 0.05). We conclude that tolerance of immature hearts to ischemia is related to amino acid utilization by transamination and increased substrate level phosphorylation, as occurring in diving mammals, suggesting retention of intrautero adaptive mechanisms.
Kupffer cell activation and endothelial cell damage after storage of rat livers: effects of reperfusion. Reperfusion injury characterized by loss of endothelial cell viability occurs after cold ischemic storage of livers for transplantation surgery. Here, ultrastructural changes in stored rat livers were examined by scanning and transmission electron microscopy. With increasing times of storage in Euro-Collins solution (4 to 24 hr) followed by 15 min of reperfusion at 37 degrees C, a sequence of structural alterations was observed involving endothelial and Kupffer cells. Widening of endothelial fenestrations occurred after 4 hr and progressed over 8 to 24 hr to retraction of cellular processes, ball-like rounding, sinusoidal denudation and ultrastructural derangements consistent with loss of cell viability. Kupffer cells exhibited progressive rounding, ruffling of the cell surface, polarization, appearance of wormlike densities, vacuolization and degranulation over a similar time course. By contrast, the structures of parenchymal and fat-storing cells were relatively undisturbed by cold storage and reperfusion. Alterations to endothelial and Kupffer cells were also studied as a function of time of reperfusion. After 24 hr of storage, endothelial cells showed retraction of cytoplasm before reperfusion that progressed quickly to loss of viability and denudation during reperfusion. Kupffer cell activation (ruffling, degranulation) during reperfusion was slower and occurred after deterioration of endothelial cells. Livers stored in Euro-Collins solution were also compared with livers stored in University of Wisconsin cold storage solution, an improved preservation medium for transplantation. University of Wisconsin solution provided better preservation of endothelial structure and markedly reduced parenchymal cell blebbing and swelling before reperfusion. University of Wisconsin solution also reduced Kupffer cell activation and release of lysosomal enzymes. In conclusion, endothelial cell deterioration followed by Kupffer cell activation occurred after increasing times of cold ischemic storage and reperfusion of rat livers. Both changes may contribute to the pathophysiology of graft failure caused by reperfusion-mediated storage injury.
Role of angioplasty in myocardial infarction management strategies: a review. The role of angioplasty in acute myocardial infarction has been extensively studied in the past few years. Although angioplasty in some circumstances can be the primary reperfusion intervention, logistic problems and the excellent results of intravenous thrombolytic therapy have resulted in postlytic angioplasty being the preferred use of this interventional strategy. Clinical trials of this strategy have not supported its routine use, however, and a much more selective application of postthrombolytic coronary artery dilation is advocated at this time.
Late volume changes in retrosternal colon bypass. Esophageal obstruction by malignancy, chemical burns, or other less common entities presents a challenge for the surgeon. Either for esophageal substitution after esophageal resection or as a bypass for the obstructed esophagus, colon interposition is often the best available option. Massive colonic enlargement requiring resection of the interposed dilated colon developed recently in 2 of our patients who had a colon bypass 22 and 10 years earlier, respectively.
Insulin-like growth factor II-mediated proliferation of human neuroblastoma. Neuroblastoma is an embryonal tumor that typically arises in cells of the developing adrenal medulla. IGF-II mRNA is expressed at high levels in the adrenal cortex before birth but it is not detectable until after birth in the adrenal medulla. Neuroblastoma cell lines corresponding to early adrenal medullary precursors did not express IGF-II, although all three cell lines we tested were growth stimulated by IGF-II. Cell lines corresponding to more mature adrenal medullary cells expressed IGF-II, and one, SK-N-AS, grows by an IGF-II autocrine mechanism (J. Clin. Invest. 84:829-839) El-Badry, Romanus, Helman, Cooper, Rechler, and Israel. 1989. An examination of human neuroblastoma tumor tissues for IGF-II gene expression using in situ hybridization histochemistry revealed that IGF-II is expressed by tumor cells in only 5 of 21 neuroblastomas, but is detectable in cells of nonmalignant tissues including adrenal cortical cells, stromal fibroblasts, and eosinophils in all 21 tumors. These findings indicate that IGF-II may function as an autocrine growth factor for some neuroblastomas and as a paracrine growth factor for others. They suggest that the growth regulatory pathways utilized by neuroblastoma mimic those used in the precursor cell type from which individual tumors arise.
The role of cellular maturation in neutrophil heterogeneity. Previous studies have shown that many neutrophil (PMN) characteristics are heterogeneous but the origin of PMN heterogeneity is unknown. It is unclear if PMN functional heterogeneity is secondary to maturational differences or due to distinct subpopulations of cells that possess different functional capacities. The PMN 31D8 antigen is a useful probe for evaluation of PMN subpopulations. The majority of PMNs (approximately 85%) exhibit a high intensity fluorescence after 31D8 monoclonal antibody (MoAb) labeling (31D8 enriched or "bright" PMNs) as determined by flow cytometric analysis. These cells are more functional than cells with low intensity fluorescence (31D8 diminished or "dull" PMNs). Various immunologic, clonogenic and functional techniques were used to study the expression of the 31D8 antigen in HL-60 cells and myeloid cells in order to evaluate antigenic and functional heterogeneity during morphologic maturation. The results of this study indicate that the percentage of 31D8 antigen positive (31D8 antigen enriched and diminished) bone marrow cells increases from 20 +/- 11% in myeloblast cells to 68 +/- 10% in promyelocytes, 93 +/- 2% in myelocytes and 99 +/- 1% in bands and PMNs. 31D8 antigen enriched cells first appear at the myelocyte stage (32 +/- 10%) and increase in bands (52 +/- 13%), marrow PMNs (62 +/- 13%) and peripheral blood PMNs (88 +/- 4%). These data indicate that the heterogeneous expression of 31D8 antigen in PMNs is due, at least in part, to maturational differences within the PMN population and raise the possibility that other heterogeneously expressed PMN characteristics are also maturationally derived. They also suggest that 31D8 antigenic expression may be a more precise indicator of myeloid functional maturation than maturation as identified by cellular morphology.
Radiculomegaly of canines and congenital cataracts--a syndrome? Radiculomegaly of single teeth is very uncommon. Our survey indicates that the canine tooth is most frequently affected. Although illustrated in a number of texts of dental anatomy, there is a lack of detailed case reports.
Vascular responsiveness in obstructed gut. Multiorgan system failure due to hypotension and sepsis is an important cause of death in patients with bowel obstruction. We have investigated the pathophysiology of this entity in an animal model. After 5 days of bowel obstruction, blood flow in the superior mesenteric artery was measured with and without Pitressin and norepinephrine given in separate experiments. In controls, Pitressin in moderate dosages caused a substantial fall in gut blood flow, which was not seen in obstructed animals (blood flow reduction 52 percent vs. 11 percent in sham and obstructed animals respectively, P less than 0.01). Similarly, norepinephrine infusion had less of an effect on gut blood flow in obstructed animals (blood flow reduction 79 percent vs. 58 percent sham vs. obstructed animals (P less than 0.05). Thus, both agents had dose-related effects on gut blood flow, which was maintained at a higher level throughout the drug infusion periods in the bowel of obstructed animals, demonstrating that splanchnic flow is less responsive to vasoactive drug infusion under these experimental conditions. Because splanchnic vasoconstriction is an important feature of normal hemodynamic homeostasis, we suggest that these results may help explain some aspects of the pathophysiology of multiorgan failure caused or worsened by systemic hypotension seen in bowel obstruction.
Plasticity in the aging brain. Reversibility of anatomic, metabolic, and cognitive deficits in normal-pressure hydrocephalus following shunt surgery. The course of idiopathic normal-pressure hydrocephalus was studied in a 78-year-old woman with a 4-year history of progressive dementia who underwent neuropsychologic testing, quantitative x-ray computed tomography, magnetic resonance imaging, and positron emission tomography with fludeoxyglucose F 18 to measure rates of regional cerebral glucose utilization. Preshunt cognitive testing demonstrated progressive deterioration during 2 years, and positron emission tomography showed significant reductions in regional cerebral glucose utilization of 34% to 49% as compared with age- and sex-matched control subjects in frontal, temporal, parietal, and whole brain regions. Periodic testing, carried out during a 2-year period after shunt surgery, showed steady improvement in clinical status. Parallel to the clinical changes, there was a significant reversal in neuropsychologic test scores with increased brain volume and increased regional cerebral glucose utilization in several brain regions. These results documented the considerable potential for recovery of compromised brain function in older subjects even after 4 years of progressive brain disease.
Pseudospasticity in Guillain-Barre syndrome. We report a woman with Guillain-Barre syndrome who developed a flexion posture of the right arm and hand resembling upper motor neuron dysfunction. EMG demonstrated that involuntary peripherally generated continuous motor unit discharges caused the posture.
Prevalence and association of asteroid hyalosis with systemic diseases. We performed a cross-sectional study of 12,205 patients, which identified 101 patients (0.83%) with asteroid hyalosis. These patients were examined for associated systemic and ocular conditions. Diabetes mellitus was found in 29 of the patients with asteroid hyalosis (29%), as compared to ten of 101 (10%) control subjects (P = .0007). An increased prevalence of systemic arterial hypertension (61 of 101 [60%] patients with asteroid hyalosis compared with 29 of 101 [29%] control subjects; P = .0001) and atherosclerotic vascular disease (30 of 101 [30%] patients with asteroid hyalosis compared with 13 of 101 [13%] control subjects; P = .006) was also discovered in the asteroid hyalosis group. Additionally, patients with asteroid hyalosis were found to be more hyperopic than control subjects (P = .009).
Immunolocation of TNF-alpha/cachectin in human melanoma cells: studies on co-cultivated malignant melanoma. We have investigated the ability of metastatic cells to produce the macrophage cytokine, TNF-alpha/cachectin, as these cells have macrophage-like properties such as infiltration and migration. We looked for TNF-alpha/cachectin in three tumor cell lines derived from human malignant melanomas and six co-cultivated malignant melanomas derived, in vitro, from these three cell lines plus angioma fibroblasts. Immunohistochemistry with an anti-TNF-alpha/cachectin monoclonal antibody showed that TNF-alpha/cachectin was produced by two of the three parent melanoma cell lines. All the tumor cells in both the co-cultivated malignant melanomas and their in vitro tumorous nodules produced TNF-alpha/cachectin, even those derived from the melanoma cell line, which originally did not. The results clearly show that TNF-alpha/cachectin can be produced by non-hematopoietic tumor cells. A co-cultivated tumor model prepared from other types of human tumor cell lines promises to provide a useful tool for exploring the relationship between TNF-alpha/cachectin and oncogenesis.
AAEM minimonograph #35: Clinical experience with transcranial magnetic stimulation. We elicited motor evoked potentials (MEPs) using transcortical magnetic stimulation in 150 control subjects aged 14 to 85 years and 275 patients with a variety of diseases. There were no significant side effects. Cortex-to-target muscle latencies measured 20.2 +/- 1.6 ms (thenar), 14.2 +/- 1.7 ms (extensor digitorum communis), 9.4 +/- 1.7 ms (biceps), and 27.2 +/- 2.9 ms (tibialis anterior). Central motor delay between the cortex and the C-7 and L-5 measured 6.7 +/- 1.2 ms and 13.1 +/- 3.8 ms, respectively. Mean spinal cord motor conduction velocity measured 65.4 m/s. MEP amplitude expressed as a percentage of the maximum M wave was never less than 20% of the M wave. A value of less than 10% is considered abnormal. MEP latency increases linearly with age and central motor delay is longer in older subjects. Compound muscle action potentials and absolute MEP amplitudes decreased linearly with age. In multiple sclerosis (MS), MEP latency and central delay were often very prolonged. The MEP was more sensitive than the SEP in MS. In amyotrophic lateral sclerosis, MEP latencies were only modestly prolonged; the characteristic abnormality was reduced amplitude. When pseudobulbar features predominated MEPs were often absent. The MEP was of normal latency in Parkinson's disease, but age-related amplitude was often increased. MEP latency and amplitude were normal in Huntington's disease. Abnormal MEPs persisted several months after stroke despite good functional recovery. The MEP could be used to advantage to demonstrate proximal conduction slowing and block in demyelinating neuropathies. In plexopathy, ability to elicit an MEP several days after onset of paresis was good evidence of neuronal continuity in motor fibers.
Contributions of the Zollinger-Ellison syndrome. The salient contributions of the Zollinger-Ellison syndrome have made it unique. No pancreatic endocrine tumor described before (insulinoma) or subsequently (glucagonoma, somatostatinoma, vipoma, pancreatic-polypeptidoma) has been the topic of such a variety of studies, or has been such an inspiration and rich source of new ideas for investigation and ultimate improvement in patient care.
Vitamin E in gastric mucosal injury induced by ischemia-reperfusion. To clarify the relationship among vitamin E, oxygen radicals, and lipid peroxidation in ischemia-reperfusion, we produced an experimental model of gastric mucosal injury in rats by ischemia-reperfusion with clamping of the celiac artery and measurements of the area of gastric erosion, thiobarbituric acid (TBA)-reactive substances, and alpha-tocopherol in serum and gastric mucosa during ischemia-reperfusion. The area of gastric erosions and TBA-reactive substances in gastric mucosa were significantly increased after 30 and 60 min of reperfusion. The serum alpha-tocopherol-cholesterol ratio and gastric mucosal alpha-tocopherol were significantly decreased after 30 and 60 min of reperfusion. On the other hand, in vitamin E-deficient rats, gastric mucosal injury induced by ischemia-reperfusion was more severe than that in vitamin E-nondeficient rats. These results indicate that vitamin E is consumed in the process of lipid peroxidation induced by oxygen radicals in ischemia-reperfusion to prevent the development of tissue damage.
Prostate specific antigen for assessing response to ketoconazole and prednisone in patients with hormone refractory metastatic prostate cancer. Serial prostate specific antigen levels were assessed in 15 patients with hormone refractory metastatic prostate cancer treated with ketoconazole and prednisone. Of the men 12 (80%) with continually increasing prostate specific antigen levels before treatment had a decrease in prostate specific antigen with a median duration of response of 3 months. Three patients (20%) had a prolonged response (greater than or equal to 8 months) as seen by a persistently decreasing prostate specific antigen and improvement in bone pain. There appears to be a small subgroup of patients with progressive prostate cancer despite androgen ablation who will benefit from ketoconazole and glucocorticoid treatment. The use of serial prostate specific antigen levels appears to help define this subgroup and avoid the need for multiple radiological procedures to assess response.
Assessment of fibrin(ogen) degradation products in preeclampsia using immunoblot, enzyme-linked immunosorbent assay, and latex-based agglutination. Plasma and serum from pregnant women with preeclampsia (N = 35) and normotensive pregnant (N = 71) and nonpregnant (N = 10) controls were screened for fibrin(ogen) degradation products (fibrinogen and cross-linked fibrin degradation products, and fibrin polymers) using three different assay systems (immunoblot, enzyme-linked immunosorbent assay [ELISA], and latex-bead agglutination assay). All tests showed statistically significant differences (P less than .05) between the preeclamptic patients and the other two groups (pregnant and nonpregnant women). The ELISA assay for total fibrin(ogen) degradation products was the most sensitive test, but was less specific than D-dimer latex. Eleven of the 35 preeclamptic women developed HELLP syndrome (hemolysis, elevated liver enzyme, and low platelet counts). Positive tests were as common in the 11 preeclamptic women who developed the syndrome as in the 24 who did not. These results suggest that fibrinolytic disorders are secondary pathophysiologic events in the course of preeclampsia, but further studies with a larger number of patients are needed.
Doppler echocardiographic evaluation of pulmonary artery flow after modified Fontan operation: importance of atrial contraction. Doppler echocardiography was used to evaluate blood flow in the pulmonary artery in 14 patients 2 to 42 months (mean (SD) 17 (12) months) after a modified Fontan operation incorporating a direct atriopulmonary anastomosis. Preoperatively six patients had tricuspid atresia, six had a double inlet left ventricle, and two had pulmonary atresia with an intact ventricular septum. The postoperative rhythm was sinus in 11 patients, junctional in one, ventricular pacing in one, and atrioventricular sequential pacing in one. In one patient the Doppler trace was unsatisfactory for analysis. In all patients forward flow in the pulmonary artery had biphasic peaks related to both atrial and ventricular contraction. The mean (SD) peak flow velocity that was synchronous with atrial contraction was 80 (30) cm/s and that synchronous with ventricular contraction was 74 (23) cm/s. The atrial contribution to total pulmonary artery flow, assessed by velocity-time integrals, varied between 22% and 73% (mean (SD) 45 (14)%). In patients with tricuspid atresia the mean (SD) peak flow velocity with atrial contraction was 90 (27) cm/s and that with ventricular contraction was mean (SD) 68 (24) cm/s. In patients with double inlet left ventricle the mean (SD) peak flow velocity was 67 (36) cm/s with atrial contraction and 80 (25) cm/s with ventricular contraction. The atrial contribution to total pulmonary blood flow in patients with tricuspid atresia was significantly higher (53 (11)%) than in those with double inlet left ventricle (37 (14)%). Pulmonary artery flow after modified Fontan operation was biphasic and was related to both atrial and ventricular contraction.