Melricflash/CW_MedAbstractsAlt huggingface dataset:
Induction of donor-type chimerism in murine recipients of bone marrow allografts by different radiation regimens currently used in treatment of leukemia patients. Three radiation protocols currently used in treatment of leukemia patients before bone marrow transplantation (BMT) were investigated in a murine model (C57BL/6----C3H/HeJ) for BM allograft rejection. These include (a) a single dose of total body irradiation (8.5 Gy TBI delivered at a dose rate of 0.2 Gy/min), (b) fractionated TBI (12 Gy administered in six fractions, 2 Gy twice a day in 3 days, delivered at a dose rate of 0.1 Gy/min, and (c) hyperfractionated TBI (14.4 Gy administered in 12 fractions, 1.2 Gy three times a day in 3 days, delivered at a dose rate of 0.1 Gy/min). Donor-type chimerism 6 to 8 weeks after BMT and hematologic reconstitution on day 12 after BMT found in these groups were compared with results obtained in mice conditioned with 8 Gy TBI delivered at a dose rate of 0.67 Gy/min, routinely used in this murine model. The results in both parameters showed a marked advantage for the single dose 8.5 Gy TBI over all the other treatments. This advantage was found to be equivalent to three- to fourfold increment in the BM inoculum when compared with hyperfractionated radiation, which afforded the least favorable conditions for development of donor-type chimerism. The fractionated radiation protocol was equivalent in its efficacy to results obtained in mice irradiated by single-dose 8 Gy TBI, both of which afforded a smaller but not significant advantage over the hyperfractionated protocol. This model was also used to test the effect of radiation dose rate on the development of donor-type chimerism. A significant enhancement was found after an increase in dose rate from 0.1 to 0.7 Gy/min. Further enhancement could be achieved when the dose rate was increased to 1.3 Gy/min, but survival at this high dose rate was reduced. These results demonstrated indirectly that dose rate affects the expression of host-type pluripotent stem cells, the progeny of which appear 3 to 6 weeks after treatment with 8 Gy TBI delivered at a dose rate of 0.1 Gy/min, but which are eradicated if radiation is delivered at a dose rate of 1.3 Gy/min. 

Category: neoplasms
Molecular basis of the activation of the tumorigenic potential of Gag-insulin receptor chimeras. A previous study showed that the human insulin receptor (IR) could be activated by insertion of a 3' portion of the cDNA encoding the beta subunit into a retrovirus genome to form a Gag-IR fusion protein. While capable of transforming cells in culture, this IR cDNA-containing virus, called UIR, was not able to induce tumors in animals. Subsequently, we isolated a spontaneous sarcomagenic variant called UIR19t from the parental UIR. UIR19t was molecularly cloned, sequenced, and found to harbor two mutations. A 44-amino acid deletion immediately upstream from the transmembrane domain of the Gag-IR fusion protein removes all the extracellular sequence of the IR remaining in the original UIR construct. In addition, a single nucleotide deletion at the 3' end results in truncation and replacement of the carboxyl-terminal 12 amino acids by 4 new amino acids. The specific kinase activity of UIR19t is 4- to 5-fold higher than that of the parental UIR. However, no new cellular substrates were detected in UIR19t-transformed cells as compared to UIR cells. Viruses containing either the 5' or the 3' deletion mutation were constructed and assessed for their biological function. Our data indicate that the 5' deletion alone is sufficient to confer tumorigenic ability. We conclude that sequence immediately upstream from the transmembrane domain imposes a negative effect on the transforming and tumorigenic potential of the Gag-IR fusion protein. 

Category: general pathological conditions
Effects of calcium on vascular smooth muscle tone. It is generally acknowledged that calcium plays a major role in the generation of vascular tone. However, in recent years it has become increasingly evident that relatively calcium-insensitive pathways of excitation-contraction coupling also exist in the vascular smooth muscle cell. Possible mechanisms of vascular smooth muscle contraction and their possible role in the pathophysiology of hypertension are reviewed. The rationale for the use of calcium channel blockers in the treatment of hypertension is discussed. 

Category: cardiovascular diseases
Prolonged indomethacin therapy for the prevention of recurrences of patent ductus arteriosus. We tested the hypothesis that prolonged maintenance indomethacin therapy would allow more effective closure of patent ductus arteriosus (PDA) and thereby decrease the recurrence rate. Thirty-nine low birthweight neonates (less than 1500 gm) with confirmed PDA were randomly assigned in a double-blind fashion to receive standard indomethacin therapy (three doses), followed either by maintenance indomethacin therapy (0.2 mg/kg/day) for 5 days or by an equivalent volume of placebo for 5 days. Of the 20 infants who received maintenance indomethacin therapy, two (10%) required additional therapy and one of these required surgical ligation. Of the 19 infants who received only the first three indomethacin doses, nine (47%) required additional therapy for PDA (p less than 0.05) and seven of these had a ligation (p less than 0.05). We conclude that maintenance indomethacin therapy, in comparison with short-term indomethacin therapy, decreases the incidence of surgical PDA ligations, eliminates most PDA recurrences, and does not increase toxic effects of indomethacin in the low birth weight infant with PDA. 

Category: general pathological conditions
Adoptive immunotherapy with high-dose interleukin-2: kinetics of circulating progenitors correlate with interleukin-6, granulocyte colony-stimulating factor level. Immunotherapy with interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells results in significant tumor regression in patients with advanced cancer. We have investigated the kinetics of circulating erythroid (BFU-E) and granulocytic-macrophage (CFU-GM) progenitors after IL-2 therapy in 11 cancer patients, mainly affected by metastatic melanoma and renal cell carcinoma. Administration of IL-2 from day 1 through day 5 constantly induced a dramatic decrease of the number of circulating BFU-E and CFU-GM, which then showed a striking rebound (up to values fourfold and sevenfold higher, respectively, than the pretherapy levels) on discontinuation of IL-2, ie, from day 5 through day 10. A similar kinetic pattern was observed during and after the second cycle of IL-2 administration. 3[H]-thymidine killing experiments showed that the cycling activity of the progenitors was virtually unmodified in the rebound phases. To explore the mechanism(s) underlying this kinetic pattern, we have analyzed the plasma concentration of several hematopoietic growth factors, including IL-1 beta, IL-3, IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, and erythropoietin (Ep). No modifications in the levels of IL-3, GM-CSF, or IL-1 beta were observed, whereas a pronounced increase of IL-6 and G-CSF concentration was monitored, starting at day 3 and peaking at day 5 of treatment (a parallel, but modest, increase of Ep level was also observed). The elevation of IL-6 and G-CSF concentration is directly correlated with and may, at least in part, underlie the subsequent rebound of circulating hematopoietic progenitors. Furthermore, the increase in IL-4 level observed at day 10 of therapy may mediate the eosinophilia gradually starting at this stage of treatment. 

Category: neoplasms
Effect of a leukocyte-platelet removal filter on ischemia induced reperfusion injury. The effect of leukocyte and platelet depletion on reperfusion injury using a leukocyte-platelet removal filter (LRF) in intracoronary thrombolysis is reported. To better define the usefulness of LRF in evaluating the effectiveness of intracoronary thrombolysis with this device, several cardiovascular variables were examined in rabbits during ischemia followed by reperfusion. The rabbits underwent cytoapheresis with LRF (n = 5) and were compared with controls without LRF (n = 5). LRF was composed of a nonwoven polyester fabric (1.8 microns, 4.6 gm). Removal of leukocytes and platelets by LRF was 98% for both. A period of 30 min equilibration was allowed before any experimental intervention, at which time the diagonal artery was occluded for 20 min and then reperfused. All arrhythmias were defined and quantified in accordance with the Lambeth Convention. Regional wall thickening was examined by a pulsed Doppler dimension system. No significant differences were observed in hemodynamic variables between the two groups; however, rabbits treated with a LRF demonstrated greater regional wall thickening (LRF group: 17 +/- 0.9%, control group: 11 +/- 0.3%, p less than 0.01), as well as significant improvement in the frequency of ventricular arrhythmias (LRF group: 12.5%, control group: 47.2%, p less than 0.01). The data suggest that LRF may help prevent arrhythmias, and preserve left ventricular contraction, during and after intracoronary thrombolysis. 

Category: cardiovascular diseases
Aspiration in bilateral stroke patients. Seventy patients with bilateral strokes underwent neurologic and videofluoroscopic barium swallowing examinations; 34 (48.6%) aspirated. Patients with aspiration were more likely to have posterior circulation strokes, abnormal cough, abnormal gag, and dysphonia. However, patients likely to aspirate can be identified best by the presence of an abnormal voluntary cough, an abnormal gag reflex, or both. The prediction of patients at risk for aspiration was not improved by additional clinical information (ie, presence of dysphonia or bilateral neurologic signs). 

Category: general pathological conditions
Cor triatriatum dexter: antemortem diagnosis in an adult by cross sectional echocardiography. Cor triatriatum dexter is a rare cardiac abnormality in which the right atrium is subdivided into two distinct chambers. This anomaly is generally attributed to the persistence of the right sinus venosus valve and it is frequently associated with severe malformations of other right heart structures. The antemortem diagnosis of the membrane may be difficult and its presence is often only established at necropsy. In a woman of 56 with Ebstein's anomaly the echocardiographic features of cor triatriatum dexter were examined before and during cardiac catheterisation. These investigations showed the position of the membrane, that there was no gradient between the two atrial chambers, and that there were perforations in the centre of the membrane. 

Category: cardiovascular diseases
Techniques of adjustable suture strabismus surgery. Adjustable sutures allow eye muscle positions to be changed following strabismus surgery, when the patient is awake and able to cooperate in muscle balance testing. Bow-tie-knot and sliding-handle sutures can be adjusted within 24 hours after surgery. Scleral traction sutures, which can be used to fix the globe to periorbital tissues during postoperative healing, can be adjusted for up to 14 days after surgery. We describe these techniques as well as an adjustable loop suture for conjunctival closure. 

Category: general pathological conditions
The dynamics of platelet thrombus formation rate, thrombus retention time, and rate of embolization on a control and heparin bonded polyurethane angio-catheter. The dynamics of platelet deposition and embolization from control and heparin bonded polyurethane catheters (CPC and HBPC) was evaluated with In-111 labeled autologous platelets (IN-PLT) and a computerized gamma camera (CGC). Ten non-heparinized dogs (18-25 kg) were catheterized in both femoral arteries with 10 cm of CPC and HBPC (5 Fr., Cordis) 24 hr after injection of 300-420 microCi of In-PLT, and imaged for 3 hr with the computerized gamma camera. The regional platelet deposition curves (RPDC) indicated multiple peaks and valleys; the curves were analyzed for early rate of thrombus formation (upswing), thrombus retention time (full width at half maxima of the RPDC-peak), and rate of embolization (downswing) on both catheters. The four parameters (mean +/- SD) of thrombosis on catheters and integral of the radioactivity time curve for the 3 hr duration of imaging were calculated from normalized counts/sec. The rate of thrombus formation and rate of embolization are higher for the control than HBPC, suggesting that heparin-bonding decreases the early rate of thrombosis and embolization. The thrombus adhesivity and retention time appear shorter for the control catheter, indicating that the control thrombogenic catheter forms multiple thrombi and emboli than HBPC. The integral appears larger for the control catheter than HBPC. In vivo (dynamic) studies, in vitro studies, and critical analyses of the radioactivity time curve were essential for complete evaluation of thrombogenicity of catheters and other cardiovascular prostheses. 

Category: cardiovascular diseases
Hypertension as a risk factor for epilepsy after aneurysmal subarachnoid hemorrhage and surgery. A prospective, consecutive series of 307 patients with aneurysmal subarachnoid hemorrhage ranging from Grades 1 to V according to the classification of Hunt and Hess on admission were evaluated to determine the incidence of epilepsy 1 to 3 years (mean, 1.4 years) after aneurysmal subarachnoid hemorrhage (SAH) and surgery. Sixty-three patients had died and one patient was lost to follow-up. Twenty-nine patients developed epileptic seizures after the SAH and surgery. The mean time from the SAH to epileptic seizure varied from 0 days (day of the SAH) to 2 years (mean, 6.7 months). The seizures were classified as focal in 9 patients (31%) and as generalized in 20 patients (69%). All patients received anticonvulsant medication after more than one seizure. The risk factors for development of posthemorrhagic/postoperative epilepsy were, in order of importance: a history of hypertension; an infarct on late computed tomographic scan; and the duration of coma after the ictus. Of the 85 patients with histories of hypertension, 17 (20.0%) developed epilepsy. Only 12 (5.4%) of the 222 nonhypertensive patients developed epileptic seizures. The difference between the groups was significant (P = 0.0001). Computed tomographic scans were undertaken in 237 patients 1 to 3 years (mean, 1.4 years) after the SAH and surgery. Postoperative epilepsy was significantly associated with infarcts visualized on computed tomographic scan (P = 0.0005). 

Category: cardiovascular diseases
Coronary angioplasty in symptomatic patients after bypass surgery. With the availability of percutaneous transluminal coronary angioplasty (PTCA), the management of patients who present with recurrent angina following coronary artery bypass surgery (CABG) has changed. From January 1987 to December 1988, 149 symptomatic post CABG patients underwent coronary angiography at our institution. Ninety were treated with medical antianginal therapy, 14 had repeat surgery, and 45 underwent PTCA. Complications of repeat CABG included one death, two perioperative myocardial infarctions, and four patients with postoperative supraventricular arrhythmia. PTCA was performed on 42 lesions in 37 native vessels (88% success rate), and on 24 lesions in 23 vein grafts (91.7% success rate). Complications included acute reocclusion (one patient), peripheral artery occlusion (one patient), hematoma formation (one patient), and periprocedure myocardial infarction (one patient). No deaths occurred. At a mean follow-up of 5.9 +/- 3.8 months, 10 patients had recurrent symptoms, six of whom were found to have restenosis. Repeat PTCA was successfully accomplished in four patients; the other two were treated medically. It is concluded that PTCA is a feasible alternative to repeat CABG in selected patients and can be achieved with a high success rate and minimal complications. 

Category: general pathological conditions
Malignant fibrous histiocytoma of soft tissue. A population-based epidemiologic and prognostic study of 137 patients. Epidemiology and prognosis were analyzed in a consecutive, population-based series of 137 patients with malignant fibrous histiocytoma of soft tissue in the extremities and trunk wall, with a complete follow-up of minimum 3 years. All but one patient were treated by surgery in 28 cases combined with adjuvant radiotherapy or chemotherapy. The annual incidence was 0.42/10(5). The ratio men to women was 1.1. The median age was 64 years (range, 22 to 87 years). The thigh was the most common location. The median size was 6 cm. Superficial tumors constituted 43% and were smaller than deep-seated tumors. Eighty-three tumors were storiform-pleomorphic, 53 were myxoid, and one was of inflammatory type. The myxoid tumors were smaller and more often superficial. The cumulative 5-year survival rate for all patients was 0.7, but differed markedly between the histologic types; it was 1.0 in patients with myxoid tumors and 0.5 in patients with storiform-pleomorphic tumors. In the 77 patients with storiform-pleomorphic tumors without metastases at presentation, only tumor size larger than 10 cm and tumor necrosis independently impaired survival. The 23 patients who had none of these risk factors had a 5-year survival rate of 0.8. 

Category: neoplasms
Selenium in forage crops and cancer mortality in U.S. counties. The potential protective effect of selenium status on the risk of developing cancer has been examined in animal and epidemiologic studies. This ecological study investigated the association between U.S. county forage selenium status and site- and sex-specific county cancer mortality rates (1950-1969) using weighted least squares regression. Consistent, significant (p less than .01) inverse associations were observed for cancers of the lung, rectum, bladder, esophagus, and cervix in a model limited to rural counties and for cancers of the lung, breast, rectum, bladder, esophagus, and corpus uteri in a model of all counties. No consistent significant positive associations were observed in the rural county models. This remarkable degree of consistency for the inverse associations strengthens the likelihood of a causal relationship between low selenium status and an increased risk of cancer mortality. 

Category: neoplasms
Myasthenic thymus and thymoma are selectively enriched in acetylcholine receptor-reactive T cells. We compared T-cell proliferative responses to acetylcholine receptor (AChR) and to purified protein derivative (PPD) (of tuberculin) of hyperplastic thymus, thymoma, and blood cells from patients with myasthenia gravis (MG). Hyperplastic MG thymus cells gave significantly higher and more consistent responses to AChR than parallel cultures of autologous blood cells, whereas responses to PPD showed an opposite trend. Thus there was a preferential localization of AChR-reactive T cells in the hyperplastic MG thymus. Furthermore, there was a strong correlation between blood and thymus cell responses to PPD (but not to AChR), arguing that the hyperplastic MG thymus contains a sample of sensitized peripheral T cells. By contrast, both AChR- and PPD-responsive T cells were almost undetectable in thymus from nonmyasthenic patients, which is evidently much less receptive to circulating T cells. Cells from MG thymomas showed the highest stimulations by AChR but did not consistently react to PPD. However, the uninvolved thymus adjacent to these thymomas behaved almost identically to the hyperplastic samples described above. Our interpretation is that AChR-specific T cells are initially sensitized in the MG thymoma but are selectively trapped in the hyperplastic thymus after being primed elsewhere. 

Category: general pathological conditions
Decreased toxicity of polymorphonuclear neutrophils toward hepatocytes isolated from rats with acute inflammatory reaction. We have recently demonstrated that polymorphonuclear neutrophils were toxic to hepatocytes through a protease-mediated mechanism. Since synthesis of antiproteases is markedly increased during acute inflammatory reaction, the aim of this work was to investigate the toxicity of neutrophils against normal vs. inflammatory rat hepatocytes. Acute inflammatory reaction was induced by subcutaneous injection of turpentine 24 hr before the experiments. Hepatocytes from normal and turpentine-treated rats were isolated by collagenase digestion. They were incubated with human neutrophils stimulated by 1 mg/ml opsonized zymosan. Cytotoxicity was quantified by the percentage of alanine aminotransferase activity released by hepatocytes in culture medium after an 18-hr incubation period. By comparison to normal hepatocytes, inflammatory hepatocytes were more resistant to the toxicity of neutrophils. At a neutrophil/hepatocyte ratio of 20:1, the alanine aminotransferase activity releases were 53.7% +/- 5.4% (mean +/- 1 S.E.) and 27.4% +/- 4.8% for normal and inflammatory hepatocytes, respectively. Similarly, inflammatory hepatocytes were found to be less sensitive than normal hepatocytes to the toxic effect of purified neutrophil cathepsin G. In contrast, both types of hepatocytes exhibited the same sensitivity to H2O2 generated by a system consisting of glucose and glucose oxidase. Two arguments suggested that the resistance of inflammatory hepatocytes to protease toxicity was explained by an increased production of antiproteases by these cells: (a) when tested against cathepsin G and porcine pancreatic elastase activities, the protease inhibitory capacity of conditioned medium from inflammatory hepatocytes was higher than that of conditioned medium from normal hepatocytes; (b) conditioned medium from inflammatory hepatocytes markedly reduced the toxicity of stimulated neutrophils as that of cathepsin G. 

Category: general pathological conditions
Right ventricular function and metabolism. Right ventricular protection may be limited with current methods of cardioplegic delivery. Sensitive measurements of right and left ventricular function and metabolism were made in 30 patients undergoing elective coronary artery bypass surgery with cold cardioplegic arrest. Myocardial adenine nucleotide concentrations decreased with cardioplegia and reperfusion in both the right and left ventricles despite adequate levels of precursors, suggesting perioperative mitochondrial dysfunction. Postoperatively, right and left ventricular pressures were measured with micromanometer catheters and volumes were measured by nuclear ventriculography. Right and left ventricular systolic elastance was calculated by the isochronic method and by the end-systolic method. Both methods provided sensitive indexes of end-systolic elastance. This study demonstrated that right ventricular function and metabolism can be evaluated by methods analogous to methods used in the left ventricle. These results suggest that right ventricular functional and metabolic recovery are delayed despite apparently adequate myocardial protection. Sensitive measurements may permit improved assessment of alternative methods of right ventricular protection. 

Category: cardiovascular diseases