shukoor65/lab-rag-model huggingface dataset:
Repetitive sinoatrial exit block as the major mechanism of drug-provoked long sinus or atrial pause. Prolonged sinus or atrial pause occurred in six patients with paroxysmal supraventricular tachycardia after drug administration. All six patients had normal sinus node function during control electrophysiologic study; the sinus cycle length ranged from 510 to 900 ms (mean 743 +/- 141) and the longest sinus node recovery time ranged from 800 to 1,230 ms (mean 1,018 +/- 168). A long sinus or atrial pause occurring at the termination of tachycardia or cessation of atrial pacing, ranging from 3,100 to 8,200 ms (mean 6,270 +/- 1,674), was provoked by the administration of various drugs. These included an intravenous bolus injection of adenosine triphosphate (5 mg; one patient), intravenous bolus injection of verapamil (5 mg; one patient), a combination of a single oral dose of diltiazem (120 mg) and propranolol (20 to 40 mg; three patients), oral diltiazem (240 mg/day; one patient) and a combination of oral diltiazem (240 mg/day) and propranolol (160 mg/day; one patient). In five patients, low frequency deflections suggestive of sinus node activity with a cycle length between 620 and 3,500 ms were recorded during pauses. These findings suggest that repetitive sinoatrial exit block was responsible for the pause. Sinus slowing with a long arrest suggesting suppression of sinus automaticity was also noted in three of these five patients; the longest sinus arrest in these three patients was 4,160, 4,800 and greater than 4,910 ms, respectively. The remaining patient with a pause of 6,840 ms had no recordable sinus activity, either reflecting suppression of sinus automaticity or technical failure.
Intracranial aneurysms in sickle-cell anemia: clinical features and pathogenesis. Intracranial aneurysms are an unusual complication of sickle-cell anemia; only 15 patients have been described in the world literature. An additional 15 patients with sickle-cell anemia and subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms are presented. There was a high incidence of multiple aneurysms (60%); some of which were in unusual locations. The clinical and pathological features of this series of patients have provided a paradigm for acquired aneurysm formation that may be applicable to other intracranial aneurysms. Thirteen patients underwent craniotomy and clip ligation; the perioperative management of these patients is discussed. Of these 13, eight had a good recovery, three were left with moderate disability, one patient died of surgical complications, and one died of complications related to sickle-cell anemia. Two of the 15 patients died of SAH. The authors propose that endothelial injury from the abnormal adherence of sickle erythrocytes to the endothelium is the initiating event in arterial wall injury. Subsequently, there is fragmentation of the internal elastic lamina and degeneration of the smooth-muscle layer. Hemodynamic stress at these loci of arterial wall damage results in aneurysm formation. This hypothesis also explains other cerebrovascular manifestations of sickle-cell anemia, namely vaso-occlusive disease and hemorrhage without aneurysm formation. Pathological material from this series and data from the literature are presented to support this hypothesis.
Time course of recovery from frostbitten phrenics after coronary artery bypass graft surgery. Bilateral diaphragmatic paralysis developed in a patient after coronary artery bypass graft surgery during which cold cardioplegia was used. The patient's progress and eventual recovery over an 18-month period is described, with particular reference to chest wall motion and respiratory pressure measurements.
Necrotizing bronchial aspergillosis in a patient receiving neoadjuvant chemotherapy for non-small cell lung carcinoma. We describe a case of necrotizing bronchial aspergillosis which developed after lobectomy following neoadjuvant chemotherapy in a 73-year-old woman with non-small cell lung cancer. The lesion was visualized and biopsied through FBS, which played a useful role for early diagnosis of this disease. Itraconazole therapy was effective and safe.
Effect of antihypertensive therapy on focal stroke in spontaneously hypertensive rats. Spontaneously hypertensive rats subjected to focal cerebral ischemia develop larger infarcts than normotensive rat strains. To determine whether antihypertensive therapy decreases infarct volume in hypertensive rats, 60 13-week-old animals were treated with 20 mg/kg hydralazine added daily to the drinking water for 1.5, 6, 10, or 16 weeks and then subjected to focal cerebral ischemia by tandem right common carotid artery and middle cerebral artery occlusion. Blood pressure in the treated groups was substantially lower than that in untreated groups after 1 week of hydralazine therapy and remained lower for the entire treatment period in all four experiments. Mean infarct volume in spontaneously hypertensive rats treated for 10 (p = 0.02) or 16 (p = 0.005) weeks, but not 1.5 or 6 weeks, was significantly less than that in the untreated controls. The percentage reduction of infarct volume in animals treated for 10 and 16 weeks was similar. This study demonstrates that antihypertensive therapy decreases infarct volume in hypertensive rats subjected to focal cerebral ischemia. This treatment effect appears to be dependent on the duration of therapy, and the magnitude of the treatment effect seems to plateau by 10 weeks of therapy.
The effects of resection of the proximal part of the fibula on stability of the knee and on gait. We studied six patients to determine the effects of unilateral marginal resection of the proximal part of the fibula on stability of the knee and on gait. At the time of the operation, the fibular collateral ligament and the tendon of the biceps femoris were reattached, but no attempt was made to stabilize the fibula otherwise. The patients were tested an average of sixty-one months after operation. Stability of the knee was measured with an instrumented system. Gait was evaluated with an optical electronic three-dimensional digitizing system and a multicomponent force-platform. The gait of six healthy control subjects of similar age was also studied, and the reproducibility of measurements of stability of the knee was investigated in four healthy adults. There were significant differences between the side on which an operation had been done and the contralateral side with regard to the extent of anterior translation and of total anterior-posterior translation of the tibia at both 20 and 90 degrees of flexion of the knee, and in total varus and valgus rotation of the knee (the number of degrees from a position of maximum varus to one of maximum valgus angulation) at 20 degrees of flexion. The measurements of gait and of motion of the knee were found to be normal when compared with those in the control subjects. In the ground-reaction measurements, there were some significant differences from normal in the medial-lateral plane, but they were clinically unimportant. Resection of the proximal part of the fibula can lead to instability of the knee.
Bacterial meningitis following spinal anaesthesia for caesarean section. We report a case of meningitis caused by inadvertent introduction of bacteria following spinal anaesthesia for Caesarean section. The technique of performing the spinal anaesthesia is reviewed. Meningitis may occur, although very rarely, despite meticulous aseptic techniques. It is vital that meningitis should be considered in the differential diagnoses of post-spinal headache when patients present with headaches, pyrexia and meningism in the postoperative or postpartum period.
Portal venous system after portosystemic shunts or endoscopic sclerotherapy: evaluation with Doppler sonography. We sought to determine the usefulness of duplex Doppler sonography in the assessment of blood flow and clot formation in the portal vein in 44 patients with portal hypertension and bleeding esophageal varices who had undergone either endoscopic sclerotherapy (28 cases) or portosystemic shunt procedures (16 cases). The main, left, and right portal veins (collectively referred to as intrahepatic portal veins), superior mesenteric vein, splenic vein, and shunt were assessed for flow direction, presence of thrombi, and collaterals. Patent shunts were visualized in 12 (75%) of the 16 cases. Clot was detected in 27 (69%) of 39 intrahepatic portal veins in patients with end-to-side shunts, in six (67%) of nine intrahepatic portal veins in patients with distal splenorenal shunts, and in five (5%) of 92 intrahepatic portal veins in patients who had had endoscopic sclerotherapy. Flow in the main portal vein was hepatopetal in two (15%) of 13 patients with patent shunts (one end-to-side portacaval shunt and one distal splenorenal shunt). Flow in the main portal vein was hepatopetal in 26 (93%) of 28 patients who had had endoscopic sclerotherapy. Our data suggest endoscopic sclerotherapy preserves antegrade portal flow and results in fewer portal vein clots than surgical portosystemic shunts do. Patterns of thrombosis and flow direction vary unpredictably from patient to patient. Shunt patency should not be inferred without direct visualization of the shunt.
Funic reduction for the management of umbilical cord prolapse. The current management of umbilical cord prolapse centers on attempts to alleviate the pressure of the presenting part on the cord while preparation for cesarean section is being made. A 10-year experience in which there were vigorous attempts to accomplish safe vaginal delivery after the diagnosis of umbilical cord prolapse is presented. Eight cases of umbilical cord prolapse occurred, a frequency of 1 in 277 deliveries (0.37%), all of which had a normal immediate neonatal outcome. Vaginal delivery was accomplished in seven patients (87.5%); diagnosis was made in two of them when delivery was imminent. Five patients were more remote from delivery and had successful funic reduction (manual replacement of the prolapsed cord). Funic reduction is proposed as a potentially beneficial initial step in the management of umbilical cord prolapse.
Sudden unexpected death due to papillary fibroma of the aortic valve. Report of a case and review of the literature. The case of the sudden unexpected death of a 21-year-old man due to embolization of segments of an aortic valve papillary fibroma to the left main and anterior descending coronary artery is presented. The literature regarding cardiac papillary fibroma is reviewed with particular reference to those cases associated with sudden death.
Laser balloon angioplasty: potential for reduction of the thrombogenicity of the injured arterial wall and for local application of bioprotective materials. Mitigation of adverse biologic reactivity after balloon angioplasty is necessary before the incidence of restenosis can be appreciably reduced. A brief review of experimental evidence supports the hypothesis that the thrombogenicity of the injured arterial wall can be reduced by a suitable level of thermal denaturation or cross-linking of thrombogenic proteins. In addition, the concept of local pharmacologic therapy, which can be provided with laser balloon angioplasty at the site of arterial injury, is introduced. Preliminary in vitro and in vivo data suggest that guide catheter-injected albumin-heparin conjugates fabricated as water-insoluble microspheres remain adherent to the injured luminal surface and deeper arterial layers after physical trapping by the inflated balloon and subsequent laser/thermal exposure. The combination of initially adequate luminal morphology, reduction of the thrombogenicity of the injured arterial wall and application of local pharmacologic therapy with laser balloon angioplasty may eventually prove helpful in reducing the incidence of restenosis.
Innominate artery occlusive disease: surgical approach and long-term results. We reviewed our experience with 54 patients who underwent innominate artery revascularization during a 10-year period. Their age range was from 16 to 75 years (mean, 49.8 years). The innominate artery alone was involved in 21 patients (39%); the remaining patients had additional arch vessel obstructions. Before operation, neurologic symptoms occurred in 25 patients (46%), arm ischemia related to claudication and microembolization occurred in 8 patients (14%), a combination of symptoms occurred in 17 patients (32%), and no symptoms were noted in 4 patients (8%). The extrathoracic approach to surgery was used in 16 patients (30%). Eleven of the 38 patients in whom the intrathoracic approach was used had endarterectomy of the innominate artery; in three of those, the procedure was combined with left common carotid endarterectomy. Bypass grafts were used in the other 27 patients undergoing procedures with an intrathoracic approach; in six of those, bypass was combined with carotid endarterectomy. No operative deaths occurred. Perioperative revascularization failure occurred in four cases; all of those patients underwent a second revascularization procedure, with a secondary patency rate of 100%. In four patients, late occlusion was noted at 6 months and at 1, 1.5, and 10 years. One patient had a permanent perioperative neurologic deficit in the distribution of the left carotid artery after a combined common carotid endarterectomy/innominate endarterectomy procedure. No neurologic deficits were directly related to the innominate artery territory. Long-term actuarial survival was 83% at 10 years. Early and late graft failures were related to inadequate inflow in bypass grafts, progression of distal disease in arteritis, and primary closure in endarterectomy.
Idiotypic cross-reactivity of immunoglobulins expressed in Waldenstrom's macroglobulinemia, chronic lymphocytic leukemia, and mantle zone lymphocytes of secondary B-cell follicles. Monoclonal antibodies (MoAbs) specific for autoantibody-associated cross-reactive idiotypes (CRIs) of Waldenstrom's IgM react frequently with the surface Ig (slg) expressed by leukemia cells of patients with chronic lymphocytic leukemia (CLL). Evaluation of the molecular basis for this cross-reactivity indicates that such CRIs are encoded by conserved antibody variable region genes (V genes) that have undergone little or no somatic hypermutation. We find that such anti-CRI MoAbs stain a subpopulation of cells within the mantle zones surrounding the germinal centers of normal human tonsil. In contrast, MoAbs specific for variable region subgroup determinants react with cells in both the mantle zones and germinal centers of secondary B-cell follicles. To test whether mantle zone B cells not reactive with existing anti-CRI MoAbs may express slg bearing as-yet-unrecognized CRIs present on Igs produced by neoplastic cells of some patients with Waldenstrom's macroglobulinemia or CLL, we immunized mice with purified Waldenstrom's IgM that have been characterized for their variable region subgroups using subgroup-specific antisera raised against synthetic peptides. The supernatants of hybridomas generated from the splenocytes of immunized mice were screened for their ability to stain a subpopulation of mantle zone lymphocytes in human tonsil. With this approach, two new anti-CRI MoAbs were identified, designated OAK1 and VOH3. OAK1 binds to a CRI present on a subset of kappa light chains of the VK1 subgroup. VOH3 recognizes a CRI determinant(s) present on a subset of antibody heavy chains of the VH3 subgroup. Flow cytometric analyses demonstrated that OAK1 specifically binds leukemia cells from 5 to 20 patients (25%) with kappa light chain expressing CLL. In addition, VOH3 reacted with the leukemia cells from 1 of 17 (6%) patients tested. The success of these methods demonstrates that the variable regions of the Igs produced by mantle zone B cells share idiotypic determinants with Igs expressed in B-cell CLL (B-CLL) and Waldenstrom's macroglobulinemia.
Suturing or stapling in gastrointestinal surgery: a prospective randomized study. West of Scotland and Highland Anastomosis Study Group. A prospective randomized study of 1004 patients is reported, comparing surgical stapling and manual suturing techniques in the construction of gastrointestinal anastomoses. The incidence of clinical leaks was similar between the two groups (sutured 3.2 per cent, stapled 4.7 per cent; P = 0.22), while for radiological leaks the incidence was significantly higher in the sutured group (12.2 per cent versus 4.1 per cent, P less than 0.05). Stapling instruments afforded significantly quicker anastomoses, mean(s.e.m.) 28.1(0.7) versus 14.3(0.5) min (P less than 0.001), and quicker operations, 115.5(2.4) versus 103.8(2.2) min (P less than 0.001). The two groups were found to be comparable in other respects such as operative mortality, requirements for blood transfusion, incidence of infective complications, recovery of gastrointestinal function and postoperative hospital stay.
Hepatitis C in liver transplant recipients. HCV infection is commonly found in patients with chronic liver disease undergoing liver transplantation. However, the presence of antibody to HCV does not appear to be associated with the development of hepatitis posttransplant. No other risk factors were identified that appear to predispose patients to development of hepatitis in the posttransplant period, including amount of blood product exposure. The role of immunosuppression in the acquisition and expression of liver disease caused by HCV remains to be determined.
Cholestasis and changes of portal pressure caused by chlorpromazine in the perfused rat liver. Chlorpromazine (10 mumol/L) causes a marked increase in portal pressure in perfused rat liver. Simultaneously, oxygen consumption, hepatic clearance of taurocholate and bile flow are diminished. These effects are prevented by the cyclooxygenase inhibitors indomethacin (15 mumol/L), acetylsalicylate (3 mmol/L) or ibuprofen (200 mumol/L). On addition of chlorpromazine the liver releases increased amounts of prostaglandin D2; this increase does not occur in the presence of indomethacin. At higher concentrations of chlorpromazine (100 mumol/L) the inhibition of taurocholate clearance and bile flow is accompanied by only a moderate increase of portal pressure, and indomethacin is without effect. At this high concentration, substantial cell damage, as indicated by the release of lactate dehydrogenase, is present. We conclude that arachidonic acid-derived metabolites, notably prostanoids, are involved in the inhibition of bile flow and of taurocholate clearance observed at low concentrations of chlorpromazine. The data suggest that changes in the microcirculation are responsible for the impairment of the liver functions. At higher concentrations of chlorpromazine the cell toxicity of the drug becomes prominent.
Prevention of an air embolism by moderate hypoventilation during surgery in the sitting position. The effect of ventilation (normo-, hypo-, and hyperventilation) on transverse sinus pressure (TSP), central venous pressure (CVP), mean arterial blood pressure (mABP), and heart rate was studied in 15 patients undergoing neurosurgical treatment in the sitting position for tumors of the posterior fossa, and the findings were compared with the influence of positive end expiratory pressure (PEEP) on these parameters. TSP was not influenced significantly by PEEP ranging from 0 to 15 mbar, whereas CVP increased. At the same time, mABP decreased slightly. In contrast, TSP showed characteristic changes with varying ventilation: during normoventilation [end expiratory CO2 pressure (PECO2), 38 mm Hg], TSP was 3 mm Hg and increased to 7 mm Hg on average with hypoventilation (PECO2, 44 mm Hg), whereas hyperventilation (PECO2, 32 mm Hg) caused a reduction in TSP to the atmospheric range. At the same time, CVP remained unchanged, whereas mABP increased with hypoventilation. Presuming that the risk of venous air embolism is closely related to the level of TSP, our results allow the following conclusions. 1) PEEP does not seem to be effective in preventing venous air embolism. 2) Hyperventilation is dangerous in the sitting position, as TSP is reduced to the atmospheric and even subatmospheric range. 3) To prevent air embolism, moderate hypoventilation is recommended during the most critical period of exposing the posterior fossa followed by normoventilation when surgery of the actual lesion has begun.
Pyruvate dehydrogenase deficiency due to a 20-bp deletion in exon II of the pyruvate dehydrogenase (PDH) E1 alpha gene. A 20-bp deletion in the last exon of the pyruvate dehydrogenase (PDH) E1 alpha gene was found in a severely affected female patient diagnosed with PDH deficiency. PDH-complex activity in the patient's fibroblasts was 22% of that in normal controls. The mutation was characterized using PCR techniques with both patient cDNA and genomic DNA, followed by sequencing of the products. E1 beta cDNA sequence was found to be the same as that in controls. The deletion causes a frameshift and the occurrence of a premature stop codon. Western blot analysis revealed an extra band migrating just above the PDH E1 beta band. Northern blot analysis showed normal levels of both E1 alpha and E1 beta message when probed with the respective cDNAs. However, a larger intermediate-size transcript was observed for this patient in the E1 beta blot. The 20-bp deletion was not found in either parent's genomic DNA, and hence we conclude that the mutation must have occurred de novo, either in the germ-line cells or immediately following fertilization.
Induction and prevention of radiocontrast-induced nephropathy in dogs with heart failure. Radiocontrast-induced nephropathy (RCIN) is a clinically important cause of acute renal failure with no effective treatment. Recognizing the high incidence of RCIN in humans with severe congestive heart failure (CHF), this study was designed to test the hypotheses that dogs with experimental CHF are at increased risk for RCIN and that pharmacologic renal levels of atrial natriuretic factor (ANF) can prevent RCIN in this model. In chronic experiments, three groups of five conscious dogs received intravenous radiocontrast (7 ml/kg). One group consisted of normal controls, while the two other groups had experimental CHF induced by eight days of ventricular pacing at 250 beats per minute. One of the CHF groups received an infusion of ANF (30 ng/kg/min) into the suprarenal aorta for one hour before, during and after the infusion of radiocontrast to achieve pharmacologic renal plasma levels. Renal function remained stable in the normal controls in contrast to the consistent decreases in daily creatinine clearance during the five days following radiocontrast in experimental CHF. In addition, ANF prevented radiocontrast-induced reductions in creatinine clearance in dogs with experimental CHF. Additional studies performed in two groups of anesthetized dogs with experimental CHF demonstrated that, in this model of RCIN, the reduction in renal function appears biphasic, and the action of ANF may be to increase glomerular filtration rate prior to radiocontrast, thus allowing a maintenance of renal function during and after radiocontrast.