shukoor65/lab-rag-model huggingface dataset:
Effect of ischemia on protein synthesis in the septic liver. The effect of ischemia on hepatic protein synthesis during sepsis is not known, but is of clinical relevance, since hepatic blood flow decreases during the late phase of sepsis. In this study, synthesis of acute-phase proteins was measured in perfused livers of rats 16 hours after sham operation or cecal ligation and puncture. Livers from each group had 45 minutes of complete ischemia or control perfusion. Protein synthesis was measured during two hour perfusion after the ischemia or control period, by determining incorporation of 3H-leucine into total secreted trichloracetic acid precipitated proteins, immunoprecipitated complement component C3 and albumin and phosphotungstenate-precipitated alpha 1-acid glycoprotein. Lactate, glutamine-oxalacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) levels in the perfusate were measured during preischemic and postischemic perfusion. Tissue glutathione levels were measured at the end of the perfusion. Synthesis of alpha 1-acid glycoprotein was increased by 100 per cent and albumin synthesis decreased by 46 per cent in septic livers, consistent with an acute-phase response and apparent downregulation of albumin synthesis during early sepsis. Synthesis rates were reduced by 50 to 60 per cent after ischemia in perfused livers from sham operated rats and 70 to 80 per cent in livers from septic rats. Hepatic production of interleukin-1 was not different between the groups during perfusion. GOT and GPT levels increased significantly during ischemia of both nonseptic and septic livers and rapidly returned toward baseline during reperfusion. Lactate levels were higher in perfusate of septic than of nonseptic livers before ischemia and increased further during ischemia. The results suggest that ischemia inhibits production of secreted hepatic proteins similarly in nonseptic and septic livers, but perhaps to a slightly greater extent in septic livers.
Insulin resistance. A multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidemia, and atherosclerotic cardiovascular disease. Diabetes mellitus is commonly associated with systolic/diastolic hypertension, and a wealth of epidemiological data suggest that this association is independent of age and obesity. Much evidence indicates that the link between diabetes and essential hypertension is hyperinsulinemia. Thus, when hypertensive patients, whether obese or of normal body weight, are compared with age- and weight-matched normotensive control subjects, a heightened plasma insulin response to a glucose challenge is consistently found. A state of cellular resistance to insulin action subtends the observed hyperinsulinism. With the insulin/glucose-clamp technique, in combination with tracer glucose infusion and indirect calorimetry, it has been demonstrated that the insulin resistance of essential hypertension is located in peripheral tissues (muscle), is limited to nonoxidative pathways of glucose disposal (glycogen synthesis), and correlates directly with the severity of hypertension. The reasons for the association of insulin resistance and essential hypertension can be sought in at least four general types of mechanisms: Na+ retention, sympathetic nervous system overactivity, disturbed membrane ion transport, and proliferation of vascular smooth muscle cells. Physiological maneuvers, such as calorie restriction (in the overweight patient) and regular physical exercise, can improve tissue sensitivity to insulin; evidence indicates that these maneuvers can also lower blood pressure in both normotensive and hypertensive individuals. Insulin resistance and hyperinsulinemia are also associated with an atherogenic plasma lipid profile. Elevated plasma insulin concentrations enhance very-low-density lipoprotein (VLDL) synthesis, leading to hypertriglyceridemia. Progressive elimination of lipid and apolipoproteins from the VLDL particle leads to an increased formation of intermediate-density and low-density lipoproteins, both of which are atherogenic. Last, insulin, independent of its effects on blood pressure and plasma lipids, is known to be atherogenic. The hormone enhances cholesterol transport into arteriolar smooth muscle cells and increases endogenous lipid synthesis by these cells. Insulin also stimulates the proliferation of arteriolar smooth muscle cells, augments collagen synthesis in the vascular wall, increases the formation of and decreases the regression of lipid plaques, and stimulates the production of various growth factors. In summary, insulin resistance appears to be a syndrome that is associated with a clustering of metabolic disorders, including non-insulin-dependent diabetes mellitus, obesity, hypertension, lipid abnormalities, and atherosclerotic cardiovascular disease.
Two-dimensional echocardiographic assessment of intracardiac masses in infants and children. We studied six infants and children with intracardiac masses of different causes. The diagnosis was made noninvasively using two-dimensional echocardiography in all six patients. In five patients, surgical excision of the mass was undertaken with good results. Two-dimensional echocardiography is an excellent noninvasive diagnostic tool that allows the clinician to determine the size and location of intracardiac masses in infants and children.
Toxin production by Bacillus pumilus. Two strains of Bacillus pumilus (M11 and M38) and one strain each of Bacillus cereus (M27), Bacillus subtilis (M67), and Enterobacter agglomerans (M14) were identified from the air of Lancashire cotton mills. These strains were tested for cytopathic effects in Vero cells; B pumilus and B cereus strains were also examined for haemolytic activity, lecithinase production, and proteolytic action on casein. Rounding and clumping of the Vero cells occurred after the addition of supernatants prepared from B pumilus and B cereus strains; finger-like projections developed in the cells treated with B pumilus supernatants. Minimal effects occurred with B subtilis and E agglomerans. After two hours of exposure B pumilus (M11) produced the greatest effect, but treatment with trypan blue showed that most cells exposed to the M11 strain were still alive after 96 hours of exposure; those exposed to the supernatant prepared from the M38 strain of B pumilus were dead. Sheep erythrocytes were lysed more rapidly by B cereus than by B pumilus, B cereus (strongly positive) had a greater effect on lecithin than either of the B pumilus strains (M38 weakly positive, M11 negative). All hydrolised casein but the effect was more rapid with one of the B pumilus (M11) strains. It is concluded that not only do the toxins of B pumilus differ from those of B cereus, but there are also differences between the toxins produced by the two strains of B pumilus (M11 and M38).
Cardioplegia by way of the coronary sinus for valvular and coronary surgery. Retrograde coronary sinus perfusion has recently reemerged as an attractive means of delivering cardioplegic solutions during open heart procedures. In patients undergoing aortic valve or aortic root surgery, there is no evidence that coronary sinus cardioplegia results in a better myocardial protection than that achieved with the use of standard methods of anterograde cardioplegia delivery. However, the retrograde approach provides distinct technical advantages that might favor its use as an alternative to direct coronary ostial cannulation. In select subgroups of patients undergoing coronary bypass procedures, there is a growing body of evidence that the coronary sinus route may be more effective than the anterograde route because of its superior capacity to ensure homogeneous distribution of cooling and cardioplegia in myocardial areas supplied occluded arteries. The well established safety of coronary sinus cardioplegia in the clinical setting further justifies its inclusion among techniques for ensuring adequate myocardial preservation during surgically induced ischemic arrest.
Single photon emission computed tomography in patients with acute hydrocephalus or with cerebral ischaemia after subarachnoid haemorrhage. Using single photon emission computed tomography (SPECT), cerebral blood flow was studied in eight patients with gradual deterioration in the level of consciousness after subarachnoid haemorrhage. Four had cerebral ischaemia and four had acute hydrocephalus. In patients with cerebral ischaemia, single photon emission computed tomography scanning showed multiple regions with decreased uptake of technetium-99M labelled d,l-hexamethyl-propylene amine oxime (99mTcHM-PAO) mainly in watershed areas. In patients with acute hydrocephalus, decreased uptake was seen mainly in the basal parts of the brain: around the third ventricle, around the temporal horns of the lateral ventricles, and in the basal part of the frontal lobe. After serial lumbar puncture, there was improvement of the uptake of 99mTc HM-PAO in these basal areas in three (convincingly in two and slightly in the other) of the four patients accompanied by clinical improvement in these three patients. These results suggest that patients with acute hydrocephalus and impaired consciousness after SAH, in contrast to patients with cerebral ischaemia, have decreased cerebral blood flow predominantly in the basal parts of the brain.
Retroperitoneal fibrosis as host response to papillary renal cell carcinoma. A case of papillary renal cell carcinoma associated with retroperitoneal fibrosis is described. This type of fibrosis has not been previously reported to be associated with renal cell carcinoma. The case is of additional interest in that it implicates an immune phenomenon in the pathogenesis of the fibrosis, involving both putative tumor antigens and antigens associated with tumor growth but unrelated to tumor cells.
A "twilight period" of coronary perfusion: the risk of intraoperative infarction in surgery for main left coronary obstruction. This study investigates the significance of an intraoperative period of low coronary perfusion pressure which may lead to ischemia, infarction, or both, in patients undergoing coronary bypass surgery for tight left main obstruction. "Twilight Period" (TP) was defined as the time interval from initiation of cardiopulmonary bypass to implementation of cold cardioplegia. Fifty-four patients with main left coronary obstruction (greater than 50%) were divided in three groups: Group I (20), TP less than 5 minutes; Group II (15), TP = 5-15 minutes; and Group III (19), TP greater than 15 minutes. Monitoring parameters included: systemic perfusion pressure during TP, perfusion flows, length of TP, time of ischemia, myocardial temperatures during ischemia, postoperative CK-MB level, EKG-detectable infarction, and postoperative therapeutic support requirements. Results: Intraoperative myocardial infarction by EKG was 0% in Group I, 7% in Group II, and 26.3% in Group III; mortality was 0%, 0%, and 15.7%, respectively. CK-MB values were 18 +/- 3.2 IU, Group I; 18.3 +/- 2.5 IU, Group II; and 49.4 +/- 10.3 IU, Group III. Group I vs. III: P 0.01. Levels of postoperative support: Level A, less than 12 hours; Level B, 12-36 hours; and Level C, greater than 36 hours. Intra-aortic balloon pump (IABP) was considered Level C. In Group I, 75% (15/20) fell in Level A; 15% (3/20) in Level B and 10% (2/20) in Level C. In Group II, 60% (9/15) fell in Level A; 26.7% (4/15) in Level B; and 13% (2/15) in Level C. In Group III, 36.8% (7/19) fell in Level A; 15.8% (3/19) in Level B; and 47.4% (9/19) in Level C.
Mechanisms of lymphocytotoxicity induced by extracorporeal photochemotherapy for cutaneous T cell lymphoma. Extracorporeal photochemotherapy is an effective treatment for cutaneous T cell lymphoma but its mode of action is uncertain. The reduction in viability of patients' photoirradiated buffy coat lymphocytes was correlated with a 35% increase in DNA single-strand breaks and marked decreases in cellular ATP and NAD levels (to 58 and 34% of control, respectively) immediately after photoirradiation. Complementary in vitro studies were conducted with normal human peripheral blood lymphocytes using a Therakos ultraviolet A (UVA) light box. UVA light was cytotoxic on its own but was potentiated by 8-methoxysporalen. 3-aminobenzamide, a poly (ADP-ribose) synthetase inhibitor, mitigated the cytotoxic effect of ultraviolet A light in the presence of 8-methoxypsoralen in lymphocytes and reduced the amount of nucleotide depletion they caused. 10 J/cm2 of UVA light in the presence of 300 ng/ml 8-methoxypsoralen increased the poly (ADP-ribose) synthetase activity of peripheral blood lymphocytes. Exposing lymphocytes to deoxycoformycin and deoxyadenosine was found to induce biochemical and physical effects similar to those of photochemotherapy. In summary, we have shown that the lymphocytotoxic effect of extracorporeal photochemotherapy for cutaneous T cell lymphoma is apparently mediated by DNA damage, subsequent poly (ADP-ribosyl)ation and adenine nucleotide depletion. It is not known how the DNA damage and resultant biochemical effects relate to the possible immunological mechanism of extracorporeal photochemotherapy; however, it is possible that its effects can be mimicked by other DNA-damaging agents.
Tumor growth dependent on Kaposi's sarcoma-derived fibroblast growth factor inhibited by pentosan polysulfate. A neoangiogenic response is critical for the unrestricted growth of solid tumors beyond a few millimeters in diameter. Release of adequate growth-stimulating activity from tumor cells is obviously required for the stimulation of blood vessel growth, and blockade of such stimulatory activity should repress tumor growth at the microscopic level. To test this hypothesis and to study appropriate inhibitors, we used a human adrenal cancer cell line (SW-13/K-fgf) engineered to secrete Kaposi's sarcoma-derived fibroblast growth factor (K-FGF), which we previously showed to induce growth of highly vascularized subcutaneous tumors in animals by autocrine and paracrine stimuli. In the present study, we tested different polysulfates for their selective inhibition of proliferation induced by K-FGF versus proliferation independent of K-FGF. Suramin and dextran sulfate showed slight selective inhibition of K-FGF-induced proliferation, ie, inhibition three- and five-fold greater, respectively, than the inhibition of proliferation independent of K-FGF. In contrast, heparin was inactive. The heparin analogue pentosan polysulfate (PPS), however, showed selective inhibition that was more than 2000-fold greater. The inhibitory effects of PPS on growth of SW-13/K-fgf cells, as well as endothelial cells, were fully reversible by an excess of added FGF. Daily intraperitoneal injections of PPS were tolerated well by athymic nude mice and prevented growth of subcutaneous SW-13/K-fgf tumor xenografts. PPS will be a useful tool to elucidate the effects of FGFs in vitro and in vivo and appears to be a prototype for the development of tumoricidal therapy based on targeting of growth factors.
CT of acute pancreatitis: correlation between lack of contrast enhancement and pancreatic necrosis. This study was performed to determine if a correlation exists between pancreatic parenchymal enhancement or lack thereof on contrast-enhanced CT and surgical evidence of pancreatic necrosis. Accurate CT assessment of pancreatic vascular perfusion would be helpful in preoperative planning before pancreatic debridement and necrosectomy. The CT scans and medical records were blindly and retrospectively reviewed in 13 patients with the operative diagnosis of pancreatic necrosis. In all cases, CT examinations preceded surgery within 72 hr. Surgical and pathologic findings served as the gold standards for the diagnosis of pancreatic necrosis. Seven (54%) of 13 patients had a region or regions of parenchymal necrosis within the head, body, and/or tail of the pancreas seen during surgery. All seven of these patients had no pancreatic enhancement on CT in at least one region of the pancreas (CT sensitivity = 100%). In four of the seven, two regions were found to be necrotic at surgery, but only one of the two segments did not enhance on CT scans. In three of the seven patients, lack of contrast enhancement on CT (no enhancement of the pancreatic head and body in two patients and throughout the gland in another) correlated with necrosis in the same regions at surgery. The remaining six (46%) patients, who had peripancreatic or small, focal, and/or superficial areas of pancreatic necrosis at surgery, had normal pancreatic enhancement on CT. Our results show that regions of pancreatic necrosis found surgically correlate with lack of enhancement of pancreatic parenchyma on CT. Peripancreatic necrosis and minor areas of focal or superficial parenchymal necrosis were not detected on CT.
Shunt failure caused by valve collapse. Shunt failure due to collapse of the Mini-Holter valve was observed 13 times in 11 out of 179 children with an implanted Mini-Holter ventriculo-peritoneal (VP) or ventriculo-atrial (VA) shunt during a 10 year period. Intussusception of the proximal or distal end of the valve thus caused a shunt failure rate of 6% of the children in this series. Two children experienced this complication twice. All collapsed valves were part of a VP shunt system. Because of this experience use of the mini valve was abandoned and an adult Holter valve was implanted in children over the age of one month. Breakdown of this particular valve has not occurred in 102 children and two hundred adults with the adult Holter shunt system.
Myocardial ischemia during daily activities: the importance of increased myocardial oxygen demand. The role of increased myocardial oxygen demand in the pathophysiology of myocardial ischemia occurring during daily activities was evaluated in 50 patients with coronary artery disease and exercise-induced ST segment depression. Each patient underwent ambulatory electrocardiographic (ECG) monitoring for ST segment shifts during normal daily activities and symptom-limited bicycle exercise testing with continuous ECG monitoring. All 50 patients had ST depression greater than or equal to 0.1 mV during exercise. A total of 241 episodes of ST depression were noted in the ambulatory setting in 31 patients; only 6% of these were accompanied by angina pectoris. Significant (0.1 mV) ST depression during ambulatory monitoring was preceded by a mean increase in heart rate of 27 +/- 12 beats/min. Patients with ischemia during daily activities developed ST depression earlier during exercise (7.9 +/- 4.4 vs. 14.2 +/- 6.4 min, p less than 0.001) and tended to have significant ECG changes at a lower exercise heart rate and rate-pressure product than did those without ST depression during ambulatory monitoring. In the 31 patients with ischemia during daily activities, the mean heart rate associated with ST depression in the ambulatory setting was closely correlated with the heart rate precipitating ECG changes during exercise testing (r = 0.74, p less than 0.001).
Transoral decompression evaluated by cine-mode magnetic resonance imaging: a case of basilar impression accompanied by Chiari malformation. Cine-mode magnetic resonance imaging provides simultaneous images of cerebrospinal fluid flow dynamics. A patient with a basilar impression accompanied by a Chiari malformation and von Recklinghausen's disease who underwent transoral decompression is reported. Preoperative cine-mode magnetic resonance imaging visualized an associated obstruction of cerebrospinal fluid pulsatile flow at the level of the foramen magnum. Tonsilar herniation (Chiari I malformation) and hydrocephalus were also present. Postoperatively, the obstruction of cerebrospinal fluid flow was resolved concomitant with the correction of the cervicomedullary angulation. On the basis of observations made by magnetic resonance imaging, the surgical treatment of basilar impression accompanied by Chiari malformation is briefly discussed.
Atrial natriuretic peptide response to cardioversion of atrial flutter and fibrillation and role of associated heart failure. Plasma atrial natriuretic peptide (ANP) concentrations were measured before and 1 hour after cardioversion in 40 patients (27 with atrial flutter and 13 with atrial fibrillation) admitted for elective cardioversion. Fourteen (11 with atrial flutter and 3 with atrial fibrillation) had clinical evidence of congestive heart failure (CHF). Conversion to sinus rhythm was successful in 39 patients. The mean ANP concentration in the entire group decreased after cardioversion from 38 +/- 4 to 17 +/- 2 pmol/liter (p less than 0.001). In the subgroup with CHF, the ANP level, which was not significantly higher than that in the group without CHF, decreased from 47 +/- 8 to 19 +/- 3 pmol/liter (p less than 0.01). Neither mode of cardioversion (spontaneous 1, pharmacologic 2 and direct-current countershock 36) nor associated CHF influenced ANP response to cardioversion. One patient with atrial flutter and "failed cardioversion" had unchanged ANP level. The decrease after cardioversion in ANP concentration correlated with its control level (r = 0.88, p less than 0.001) but not with the decrease in heart rate. The ANP level in patients with atrial fibrillation was 45 +/- 9 vs 38 +/- 5 pmol/liter in those with atrial flutter (difference not significant). Arrhythmia duration, left atrial size, and ventricular rate or arterial blood pressure did not correlate with ANP concentration in any subgroup. It is concluded that (1) the ANP level is elevated comparably in patients with both atrial flutter and fibrillation regardless of the presence or absence of CHF; and (2) the level decreases, independent of the mode of cardioversion or presence of CHF, promptly after successful cardioversion.
Quantitation of estrogen and androgen receptors in hepatocellular carcinoma and adjacent normal human liver. Sex hormones have been shown to influence the development and course of several liver diseases. The worldwide predominance of hepatocellular carcinoma (HCC) in males has led to the suggestion that this disease might be hormone-responsive. Therefore, the hepatic estrogen (ER) and androgen receptor (AR) status of liver specimens from such patients was investigated. Samples were obtained from three female and six males patients undergoing liver resection; in each case, a small sample of both the tumor and adjacent normal tissue was collected. All patients had primary hepatocellular carcinoma without cirrhosis. In most cases, the tumor and the normal specimen had an equivalent content of cytosolic ER; however, three of the tumor samples (one female and two male) displayed considerably elevated cytosolic ER levels as compared to that of the normal tissue. In every sample, the tumor contained less nuclear ER than did the normal liver. When AR was measured, tumors of three patients (one female and two male) demonstrated a twofold elevation in cytosolic AR as compared to adjacent normal tissue. In the two male patients, an approximately twofold greater nuclear AR was found. Two other samples from male patients showed a modest elevation of cytosolic AR in the tumors. The patients whose tumors showed elevations in ER were not the same patients as those in whom the AR was elevated. Thus, these studies indicate that certain, but not all, specimens of HCC demonstrate either elevated ER or AR and suggest that a determination of receptor content might be useful prior to initiation of certain antihormone therapies.
Premenstrual syndrome. Tailoring treatment to symptoms. Despite the interest in premenstrual syndrome (PMS) taken by the media and the public in recent years, some women still do not recognize the cyclic nature of their symptoms. Thus, PMS continues to elude diagnosis. Dr Nader discusses the major categories of symptoms and when they occur, summarizes theories on the cause of PMS, and comments on how well these theories have been substantiated by testing. Choosing agents for treatment on the basis of symptoms to be controlled is also described.