shukoor65/lab-rag-model huggingface dataset:
Peripheral pulse pressure patterns in pregnancy hypertension. Maternal heart rate and pulse pressure patterns were examined in 30 hypertensive pregnant women using noninvasive methodology described previously. "Narrow" and "wide" pulse patterns were identified. Narrow cutaneous pulse pressure patterns, which are thought to be caused by vasoconstriction, were associated with lower birth weight infants (1870 +/- 983 versus 3225 +/- 838 g; P less than .001) and earlier deliveries (34.2 +/- 5.2 versus 37.9 +/- 2.8 weeks; P less than .05). The data suggest that these adjunctive maternal cardiovascular-system evaluation techniques may be useful in identifying patients at risk of adverse perinatal outcome by detecting vasospasm of the peripheral microcirculation.
Detection of paradoxical cerebral echo contrast embolization by transcranial Doppler ultrasound. Contrast echocardiography has been shown to be a sensitive method for detecting patent foramen ovale in embolic stroke, implying paradoxical embolization. However, not all two-dimensional echocardiographic studies are of diagnostic quality, and direct evidence for paradoxical cerebral embolization remains lacking. We addressed these problems by simultaneously using transcranial Doppler ultrasound and contrast echocardiography to compare relative sensitivity and concordance in the detection of right-to-left vascular shunting. Forty-six patients with stroke, transient neurologic defect, or question of atrial septal defect underwent study at rest and during Valsalva strain. Two-dimensional echocardiography detected shunting in 26% at rest and 15% during Valsalva strain, whereas transcranial Doppler study returned rates of 41% and 41%, respectively. Concordance was 82% and 75%, respectively. Discordant studies almost always had evidence of paradoxical contrast embolization by transcranial Doppler and intermediate findings by two-dimensional echocardiography. Transcranial Doppler is a sensitive, unambiguous technique for the detection of anatomic substrates and target organ involvement in patients suspected to have paradoxical cerebral embolization.
Effect of intrathecal fibrinolytic therapy on clot lysis and vasospasm in patients with aneurysmal subarachnoid hemorrhage. A prospective series of 30 patients with a single, angiographically verified aneurysmal subarachnoid hemorrhage (SAH) was studied for the effect of intrathecal thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) on outcome, angiographic vasospasm, and computerized tomography (CT) findings after surgery. The patients included fulfilled the following criteria: operation was performed by Day 3 after the hemorrhage, CT showed only blood in the basal cisterns, and the patient had a single aneurysm or multiple aneurysms that could be treated surgically at the same operation. The patients were divided into groups of 10, with patients receiving 3, 10, or 13 mg of rt-PA in a single intracisternal injection at the end of the operation. There were no differences between the treatment groups in overall outcome. One patient from the 3-mg rt-PA group developed a postoperative intracerebral hemorrhage, and one patient from the 10-mg rt-PA group had a postoperative epidural hematoma. There was one death in the 13-mg rt-PA group that was caused by inclusion of a segment of pericallosal artery in the clip. In all treatment groups a reduction was observed in the amount of blood seen on the postoperative CT scans compared to the preoperative CT scans. The reduction in SAH grade between the 10-mg and 13-mg rt-PA groups was significant (p less than 0.05). The difference in the severity of angiographic vasospasm between the 3-mg and 13-mg rt-PA groups was also significant (p less than 0.05).
Intraoperative electron beam radiation therapy for retroperitoneal soft tissue sarcoma. From December 1981 to December 1989, 20 patients with primary or recurrent retroperitoneal sarcoma received 4000 to 5000 cGy of external beam radiation therapy (EBRT) in conjunction with surgical resection and intraoperative radiation therapy (IORT). Seventeen of 20 patients underwent complete (14 patients) or partial (3 patients) resection. Three patients had shown evidence of metastases after EBRT by the time of surgery. The 4-year actuarial local control and disease-free survival rates of the 17 patients undergoing resection were 81% and 64%, respectively. Twelve patients received IORT at the time of resection for microscopic disease (10 patients) or gross residual sarcoma (2 patients). Of the ten patients receiving IORT for microscopic tumor, one patient has died of local failure and peritoneal sarcomatosis and two patients have died of distant metastases only. The remaining seven patients are disease-free. One patient treated for gross residual sarcoma has experienced a local failure 1 year after IORT and is without disease 7 years after salvage chemotherapy. The other patient treated for gross residual sarcoma has died of local failure. Five patients did not receive IORT at the time of resection because of the extensive size of the tumor bed. Three of these patients are disease-free with one patient alive with lung metastases and one patient dying of hepatic metastases. Aggressive radiation and surgical procedures appear to provide satisfactory resectability and local control with acceptable tolerance.
Meningioma: the role of a foreign body and irradiation in tumor formation. A case of meningioma is reported. At the age of 18 years, the patient had undergone insertion of a Torkildsen shunt through a posteroparietal burr hole for obstructive hydrocephalus secondary to a tumor of the pineal region, of which no biopsy had been made. After the hydrocephalus was relieved, he underwent irradiation of the tumor. Thirty years later, he was treated for an intracranial meningioma wrapped around the shunt. The tumor followed the shunt in all of its intracranial course. Microscopy disclosed pieces of the shunt tube within the meningioma. The role of a foreign body and irradiation in the induction of meningiomas is discussed, and a comprehensive review of the literature is presented.
Quantitation of the critically ischemic zone at risk during acute coronary occlusion using PET. Critical myocardial ischemia has been defined experimentally during acute coronary occlusion as flow reduction of 50% or more since cellular ATP depletion begins to occur beyond this flow reduction threshold, placing tissue at risk of cellular injury. To test the hypothesis that critically ischemic fractional left ventricular mass can be measured noninvasively with PET, nine dogs were imaged in a multi-slice positron camera using the perfusion tracer 13N-ammonia, while radiolabeled microspheres were injected into the left atrium during acute coronary occlusion. Images were processed using a 50% threshold and the size of the resulting perfusion defect was expressed as a fraction of total left ventricular image volume. The critically ischemic left ventricular fraction determined in vitro from the microsphere perfusion data, ranged from 5% to 30% of the total left ventricular weight and correlated closely with that determined noninvasively by PET with r = 0.94 (y = 1.05X - 2.0%). We conclude that the fraction of left ventricular myocardium rendered critically ischemic during acute coronary occlusion can be measured accurately and noninvasively in vivo using perfusion imaging with positron emission tomography.
Progressive deterioration of auditory evoked potentials after excision of an acoustic neurinoma: case report. The authors report the case of a 17-year-old girl who underwent excision of bilateral neurinomas of the cerebellopontine angle. Although her auditory evoked potentials were well maintained during the operation, they deteriorated gradually and progressively for the following 2 months. This seemed to reflect degeneration of the cochlear nerve fibers initiated by operative manipulation in the cerebellopontine angle in a patient who had no hearing when she awoke from surgery.
Diffuse pulmonary hemorrhage. Diffuse pulmonary hemorrhage is a syndrome consisting of hemoptysis, anemia, and air-space consolidation. The radiologic appearance is non-specific. Pulmonary hemorrhage may be due to a number of different causes. The differential diagnosis and the diagnostic approach are different in the immunologically intact host as compared with the immunocompromised host. This article reviews the main diagnostic considerations in diffuse pulmonary hemorrhage.
Gonococcal endocarditis complicating pregnancy: a case report and literature review. The incidence of gonorrhea has decreased substantially in the past decade. Disseminated gonorrhea is more common in women than in men, although gonococcal endocarditis is more common in men. Disseminated gonorrhea is most commonly described in women during menses or pregnancy. Only two cases of gonococcal endocarditis during pregnancy have been reported in the literature since 1942. We report a patient who experienced sudden hemodynamic decompensation at 30 weeks' gestation, resulting in fetal death. Aortic valve replacement was performed, but extensive involvement of the aortic root made complete eradication of infection impossible and eventually resulted in maternal death.
Biomechanical changes at the ankle joint after stroke. The resistance of the relaxed ankle to slow displacement over the joint movement range was measured on both sides of a group of hemiparetic stroke patients, in whom spasticity had been established for at least one year and who showed no clinical signs of contractures. The ankle joints of the age-matched normal subjects were flexible over most of the movement range, showing dramatically increasing stiffness only when the foot was dorsiflexed beyond 70 degrees, with a neutral range between 90-100 degrees, and a less dramatic increase in stiffness during plantarflexion. Hemiparetic patients showed identical curves to the normal subjects on the "healthy" side, ipsilateral to the causative cerebral lesion, but were significantly stiffer in dorsiflexion on the contralateral side, without change in the minimum stiffness range or during plantarflexion. Therefore significant changes in passive biomechanical properties occur at the affected ankle of hemiparetic subjects, predominantly as the result of a loss of compliance in the Achilles tendon, although an increase in the passive stiffness of the triceps surae may also occur. The contribution of these changes to the locomotor disability of hemiparetic patients is discussed.
Multichannel cochlear implant and electrically evoked auditory brainstem responses in a child with labyrinthitis ossificans. Ossification of the cochlea following meningitis presents a surgical challenge. Electrode mapping, especially in the young child, is difficult given the uncertainty of electrode contact with viable neural elements. This paper reviews surgical technique and the use of auditory brainstem responses to map the electrodes. A 4-year-old child deafened by meningitis at age 20 months had bilateral cochlear ossification by computed tomography. At surgery, a canal wall-down mastoidectomy and closure of the ear canal were performed. A trough around the modiolus was drilled, and the electrode array was placed in it. Post-operatively, the patient gave aversive or no responses to electrode stimulation. To assess electrode function, auditory brainstem responses to individual electrode activation were obtained under general anesthesia. Functioning electrodes could thus be selected for mapping. The patient now responds well to sound.
Left ventricular diastolic collapse. An echocardiographic sign of regional cardiac tamponade. BACKGROUND. Cardiac tamponade after cardiac surgical procedures is often associated with hemodynamically significant localized pericardial effusions. The localized collection of pericardial effusion in the postoperative period and the atypical presentation of cardiac tamponade limit the use of conventional clinical and echocardiographic signs usually seen with a circumferential pericardial effusion. Observation of left ventricular diastolic collapse in the echocardiogram of a patient with postoperative regional cardiac tamponade prompted us to explore the frequency of this sign in regional cardiac tamponade. METHODS AND RESULTS. We retrospectively analyzed the echocardiograms of 18 patients with postoperative cardiac tamponade for the following echocardiographic findings: right atrial collapse, right ventricular diastolic collapse, left atrial collapse, and left ventricular diastolic collapse. Three of the 18 patients had circumferential pericardial effusion, and 15 had loculated pericardial effusion; in 10, the effusion was predominantly posterior, and in the other five, it extended laterally or inferiorly. The conventional echocardiographic signs of cardiac tamponade such as right atrial collapse, right ventricular diastolic collapse, and left atrial collapse were present in only 3, 1, and 3 of these 15 patients, respectively, but all exhibited left ventricular diastolic collapse. Increasing pressure within the compartment of a loculated pericardial effusion reaching the limit of pericardial distensibility and consequent transient reversal of transmural left ventricular pressure during diastole are most likely the basis for diastolic collapse of the thick-walled ventricle in a setting of regional cardiac tamponade. CONCLUSIONS. We conclude that left ventricular diastolic collapse is a frequent sign of regional cardiac tamponade and could be a useful marker of tamponade in postoperative patients.
Percutaneous transluminal balloon angioplasty of stenotic standard Blalock-Taussig shunts: effect on choice of initial palliation in cyanotic congenital heart disease. To date, attempted balloon dilation of stenotic standard Blalock-Taussig shunts has been largely disappointing. It has been suggested that this may be due to the use of balloons of insufficient diameter. Balloon dilation of stenotic Blalock-Taussig shunts was attempted with use of relatively large balloons in five patients (11 to 67 months old) with cyanotic heart disease who were becoming progressively cyanotic and polycythemic (hemoglobin 17.9 +/- 1.1 g/dl) because of discrete shunt stenosis at the site of pulmonary anastomosis. Balloon diameters selected were equal to or within 1 mm of the unobstructed proximal shunt diameter. Before balloon dilation the diameter at the site of the stenosis was 2.8 +/- 0.8 mm (range 1.7 to 4); after balloon dilation it was 5.7 +/- 1.1 mm (range 4.5 to 7.5). The diameter increased in all patients (range 2.0 to 3.5 mm); the mean increase was 2.8 +/- 0.2 mm (p less than 0.005). Expressed as a percent, the increase in diameter at the stenosis ranged from 80% to 182.4% (mean 108.2 +/- 16.8%). Before balloon dilation the systemic oxygen saturation was 72.8 +/- 9.2% (range 55% to 80%) and after balloon dilation it was 83.6 +/- 2.9% (range 80% to 87%). A satisfactory increase (range 6% to 25%) in blood oxygen saturation was seen in all patients; the mean increase was 10.8 +/- 3.2% (p less than 0.01). At follow-up, the oxygen saturation by pulse oximetry was 85.8 +/- 2.9% (mean 5.8 +/- 1.7 months after balloon dilation) and the hemoglobin was 15.6 +/- 1.9 g/dl (mean 6.6 +/- 1.5 months after balloon dilation).
Cerebral infarction in young people. A study of 148 patients with early cerebral angiography. The aetiology of strokes was studied in a hospital based series of patients aged up to 40 years with precise clinical and radiological criteria. One hundred and forty five patients (75 males and 73 females) aged five to 40 years with cerebral ischaemia were evaluated. Aetiology was heterogeneous and could be classified into seven groups. Cerebral arteriograms were performed in all cases and indicated the aetiological diagnosis in most patients. Embolism was the most frequent recognised abnormality (38.4%). There were no complications of arteriography. Arterial dissections discovered by arteriography were the cause of the stroke in 10.1% of the patients. Atherosclerosis was diagnosed in 32 cases and was the commonest cause (21.6%). In one fifth of cases no cause was found. Contraceptive drugs were considered as potential cause of ischaemic stroke in 11.5%, cardiac diseases in 12.8% and haematological disorders in 8.1%. Other potential causes included migraine, inflammatory diseases, pregnancy and lacunas. Follow up in 126 cases showed that many patients had good functional recovery.
Arthrodesis of the knee with an intramedullary nail. The cases of twenty patients who had an arthrodesis in which an intramedullary nail was used for stabilization were reviewed at an average follow-up of six years. The predominant indications were infection after total knee arthroplasty and post-traumatic pain and instability. Other indications included aseptic loosening of the components of a total knee arthroplasty, reconstruction after resection of a giant-cell tumor, non-union of a fracture of the distal part of the femur or the proximal part of the tibia, and failed external-compression arthrodesis. Success was achieved in seventeen patients (85 per cent), and functional stability immediately postoperatively was gained in all twenty. Of the three patients in whom the arthrodesis failed, all had sustained an intraoperative fracture, and infection eventually developed. Of the twelve nails that were secured to the greater trochanter with a loop of stainless-steel wire, none showed evidence of proximal migration. Of the eight nails that were not thus secured, two migrated proximally, necessitating removal of the nail. Two drawbacks to this operation are the long duration and the large amount of blood that is lost. The major advantage is that a high percentage of patients have progression to a stable fusion despite serious problems. Furthermore, all but seven patients (including the six who had a tumor or who had sustained an intraoperative fracture) were able to bear full weight by the second postoperative week. Only a few patients needed an external support for walking.
Role of thromboxane and serotonin as mediators in the development of spontaneous alterations in coronary blood flow and neointimal proliferation in canine models with chronic coronary artery stenoses and endothelial injury. Platelet-mediated obstruction of stenotic and endothelium-injured coronary arteries may be important in the abrupt progression from chronic stable to unstable coronary heart disease syndromes in patients. Transcardiac accumulation of thromboxane A2 and serotonin has been demonstrated in patients as chronic stable angina is converted to unstable angina. In this study in anesthetized open chest dogs with coronary artery stenosis and endothelial injury, thromboxane A2 and serotonin were shown to be important mediators of intermittent coronary obstruction caused by platelet aggregation and dynamic vasoconstriction. Furthermore, thromboxane A2 synthesis inhibitors and receptor antagonists and serotonin receptor antagonists, singly and together, provided substantial protection against repetitive platelet aggregation and dislodgment in canine models with coronary artery stenosis and endothelial injury even when systemic catecholamine concentrations were markedly elevated. These same observations apply in chronically instrumented, awake, unsedated dogs with coronary artery stenosis and endothelial injury in which recurrent platelet attachment and dislodgment cause cyclic flow alterations that may be prevented by thromboxane A2 synthesis inhibitors and receptor antagonists and serotonin receptor antagonists. Chronically instrumented dogs with coronary stenosis and endothelial injury in which recurrent platelet attachment and dislodgment occurred also developed neointimal proliferation of varying severity within 10 days to 3 weeks; the morphologic appearance of the neointimal proliferation was identical to that found in patients who develop restenosis after coronary angioplasty.
Substitution of leucine for isoleucine in a sequence highly conserved among retroviral envelope surface glycoproteins attenuates the lytic effect of the Friend murine leukemia virus. Friend murine leukemia virus is a replication-competent retrovirus that contains no oncogene and that exerts lytic and leukemogenic properties. Thus, newborn mice inoculated with Friend murine leukemia virus develop severe early hemolytic anemia before appearance of erythroleukemia. To identify the retroviral determinants regulating these effects, we used chimeric infectious constructions and site-directed point mutations between a virulent Friend murine leukemia virus strain and a naturally occurring variant attenuated in lytic and leukemogenic effects. We found that severe hemolytic anemia was always associated with higher numbers of blood reticulocytes with budding retroviral particles. Furthermore, a remarkably conservative leucine to isoleucine change in the extracellular SU component of the retroviral envelope was sufficient to attenuate this lytic effect. Also, this leucine at position 348 of the envelope precursor protein was located within the only stretch of five amino acids that is conserved in the extracellular SU component of all murine, feline, and primate type C and type D retroviral envelopes. This observation suggested an important structural function for this yet undescribed conserved sequence of the envelope. Lastly, we observed that lytic and leukemogenic effects were attenuated by a deletion of a second repeat in the transcriptional enhancer region of the viral long terminal repeats of the variant strain.
Mesonephric rest hyperplasia. A potential diagnostic pitfall. A case of mesonephric rest hyperplasia, an incidental finding in the hysterectomy specimen of a 48-year-old woman, was initially misdiagnosed as a well-differentiated cervical adenocarcinoma. We highlight the histologic, histochemical, and immunohistochemical features of this potential diagnostic pitfall and review the relevant literature.
Coarctation: do we need to resect ductal tissue? A review of the literature as well as a retrospective review of 100 neonates undergoing operation for coarctation at Children's Hospital in Boston between 1972 and 1984 has not established clear superiority for either resection and end-to-end anastomosis or subclavian flap aortoplasty with respect to risk of recurrent coarctation. However, there is histological evidence that the juxtaductal coarctation shelf is composed of smooth muscle of ductal origin, which subsequently fibroses. This abnormal tissue may be at risk for late aneurysm development, particularly if balloon dilatation angioplasty is required. The fact that this abnormal tissue is not removed by the subclavian flap procedure is one of the inherent disadvantages of that procedure. Other disadvantages include the need to sacrifice the left subclavian artery and the fact that, unlike resection and end-to-end anastomosis, the subclavian flap procedure does not lend itself to augmentation of the hypoplastic distal aortic arch. Furthermore, occasionally a secondary coarctation membrane is present within the distal aortic arch, and though it is readily detected during the resection procedure, it can be missed with the subclavian flap procedure. Based on these considerations rather than on a demonstrated superiority of either procedure, my colleagues and I currently prefer resection and end-to-end anastomosis over subclavian flap aortoplasty.