shukoor65/lab-rag-model huggingface dataset:
Etiology of cerebral vasospasm in primates. A primate model was used to determine whether oxyhemoglobin (OxyHb), methemoglobin (MetHb), or bilirubin is likely to be responsible for cerebral vasospasm following subarachnoid hemorrhage (SAH). Forty cynomolgus monkeys were randomly assigned to one of five groups. On Day 0, each animal underwent angiography followed by right craniectomy and placement of an Ommaya reservoir with its catheter adjacent to the right middle cerebral artery (MCA). The animals received intrathecal injections twice a day for 6 days of one of the following solutions: mock cerebrospinal fluid (CSF); OxyHb; MetHb; bilirubin; or supernatant fluid from an incubated mixture of autologous blood and mock CSF. On Day 7, angiography was repeated and the animals were killed. Comparison of angiograms obtained on Day 0 and Day 7 of the experiment showed significant vasospasm of the right MCA and the right anterior cerebral and internal carotid arteries in the animal groups that had received OxyHb or supernatant fluid. There was a smaller reduction in diameter of the same vessels in the bilirubin group (not statistically significant), while no effects were observed in the groups receiving MetHb or mock CSF. Electron microscopy of the right MCA's gave results consistent with the angiographic findings. One monkey in the OxyHb group developed a delayed-onset right MCA infarction. These data suggest that OxyHb is the cause of cerebral vasospasm following SAH.
Renal sensitivity to endothelium-derived-relaxing-factor-mediated vasodilatation in the spontaneously hypertensive rat. 1. The sensitivity of the kidney to endothelium-derived-relaxing-factor-mediated vasodilatation has been investigated in the spontaneously hypertensive rat and the Wistar-Kyoto normotensive rat using an isolated perfused rat kidney model. 2. No difference in the slope, ED50 or maximum of the concentration-response curves for the endothelial-dependent vasodilators A23187, a calcium ionophore, and acetylcholine could be demonstrated between kidneys obtained from the spontaneously hypertensive and the Wistar-Kyoto normotensive rats. 3. No difference in the slope or the ED50 of the concentration-response curve for the endothelial-independent vasodilators, atrial natriuretic factor and sodium nitroprusside, could be demonstrated between kidneys obtained from the spontaneously hypertensive and the Wistar-Kyoto normotensive rats. However, in the spontaneously hypertensive rats, the maximum vasodilator response to atrial natriuretic factor, but not to sodium nitroprusside, was increased. 4. The perfused kidney from the spontaneously hypertensive rat also showed an increase in the maximum but not in the slope or ED50 of the concentration-response curve for vasoconstriction induced by the alpha 1-adrenoceptor agonist methoxamine. 5. The involvement of endothelium-derived relaxing factor in mediating the renal vasodilator response to A23187 and acetylcholine was confirmed in experiments performed in perfused kidneys obtained from normotensive Wistar rats. 6. It is concluded that the sensitivity of the kidney to endothelium-derived-relaxing-factor-mediated vasodilatation is not modified in the spontaneously hypertensive rat. This does not, however, exclude a role for the synthesis of endothelium-derived relaxing factor in the maintenance of blood pressure in the spontaneously hypertensive rat.
Facial nerve monitoring by monopolar low constant current stimulation during acoustic neurinoma surgery. Electrophysiological characteristics of monopolar low constant current stimulation, and evoked facial muscle responses to such stimulation, were evaluated in 34 cases of acoustic neurinoma. Our study, using stimulus parameters of 0.1-ms-duration pulse wave with 0.5-0.6 mA intensity, revealed that extent of spreading current depends on the current intensity, being about 1 mm from the electrode with 0.5-0.6 mA, and insulation of the electrode prevented the current from spreading through the cerebrospinal fluid, giving a reliable amount of current to the tissue. Evoked facial muscle responses to facial nerve stimulation in the internal auditory meatus and over the pons were analyzed and revealed the following: (1) The responses to stimulation in the internal auditory meatus showed no amplitude attenuation throughout the operation. (2) The responses to stimulation over the pons gradually decreased in amplitude as tumor dissection from the nerve proceeded, especially in large tumors. (3) Anatomical continuity of the nerve was obtained in 100% of small, 91.7% of medium, and 88.2% of large tumors. Our data show that monopolar low constant current stimulation is effective in obtaining the precise anatomical orientation of the facial nerve during tumor removal.
Rapid improvement in a patient with leukocytoclastic vasculitis with secondary mixed cryoglobulinemia treated with cryofiltration. A patient with leukocytoclastic vasculitis (LCV) with secondary mixed cryoglobulinemia was treated by cryofiltration in an effort to stop the progression of the disease despite the use of high dose prednisone. Three cryofiltration procedures within one week were performed on this patient. Clinical assessments made through the course of this therapy and the followup period showed excellent response. Peripheral blood mononuclear cell transformation functions (MNC-TF) were evaluated at the pre-1st and post-2nd cryofiltration treatment. MNC-TF pretreatment were significantly suppressed. Post-2nd cryofiltration, MNC-TF were improved. Our study demonstrates that cryofiltration is a safe and effective treatment of a patient with LCV with secondary mixed cryoglobulinemia, without requiring plasma replacement products.
Second operation after the failure of previous resection for epilepsy. We present our surgical experience with second operations in 15 patients with recurrent intractable partial seizures after resection for epilepsy. The interval from the first operation until the first recurrence of seizures ranged from 1 day to 7 months (mean, 62 days). The interval between the first and second operations ranged from 3 months to 12 years (mean, 38 months). Detailed video-electroencephalographic interictal and ictal recording was performed in all patients (invasive electrodes were used in 11 patients). Ictal onset was shown to be remote from the zone of previous resection in 3 of 15 cases (all 3 extratemporal and in the ipsilateral hemisphere). Recurrent seizures arose from the area of previous extratemporal resection in 2 of 15 patients, and from the area of previous temporal resection in 10 of 15 patients. Both cases of extratemporal recurrences and 3 of the 10 cases of temporal lobe recurrences in the area of previous resection were associated with residual unresected structural lesion. Of the 10 patients with local temporal recurrence, 6 had proven epileptogenicity in the residual mesial structures, and 4 had residual epileptogenicity in the unresected lateral temporal lobe. The patients have been monitored for 8 to 82 months (mean, 18 months) after the second operation: 7 patients (47%) have remained seizure-free and another 5 (33%) have achieved a reduction in seizure frequency of more than 90%. There was no mortality or significant morbidity in this series. We conclude that the extent and distribution of residual epileptogenicity after failed epilepsy surgery are highly variable.
Immune dysfunction in children after corrective surgery for congenital heart disease. OBJECTIVE: To study the effect of open- and closed-heart surgery on the immune status of infants and children. DESIGN: Prospective study. Data collected before anesthesia and surgery and 2 and 24 hrs after surgery. SETTING: Operating room and pediatric ICU in a children's hospital. PATIENTS: Children undergoing surgery for correction of congenital heart disease (age 3 months to 12 yrs). A total of 31 patients were studied (open-heart surgery, n = 25; closed-heart surgery, n = 6). MEASUREMENTS AND MAIN RESULTS: Increased neutrophil counts and lymphopenia were observed after both open- and closed-heart surgery. Serum levels of the complement components C3 and C4 were depressed after open-heart surgery, but not after closed procedures. The percentage of T3+ and T4+ lymphocytes, proliferative responses of the lymphocytes and serum immunoglobulin (Ig)G and IgM were decreased from preoperative levels after open-heart surgery. The percentage of T8+ lymphocytes and serum IgA levels did not change. Intraoperative variables and postoperative severity of illness (Pediatric Risk of Mortality score) did not correlate with immune suppression. CONCLUSIONS: The immune system is affected after pediatric cardiac surgery, particularly after open-heart surgery.
Prolongation of the pharmacologic effect of intrathecal meperidine by the use of a lipid solution of it. The possibility of prolonging the effect of intrathecally injected meperidine by the use of a lipid solution was examined in this study. An aqueous solution of 5% meperidine HCl, 250 micrograms/kg, and an equimolar solution of meperidine dissolved in iophendylate (Pantopaque) were injected subarachnoidally in two groups of rabbits (n = 9 in each) with chronically implanted catheters in the subarachnoid space at the level of L7-8. The effect of each injection was assessed by evaluation of the pain threshold in the animal's hind limbs and of the degree of motor blockade produced. The duration of analgesia and of motor blockade were significantly longer when the lipid solution was used. Six of nine animals that received the aqueous solution of 5% meperidine HCl exhibited temporary signs of agitation (i.e., biting of hind limbs). None of the animals given the lipid solution of the drug did. The findings are attributed to the slow release of meperidine from the lipid phase that serves as a drug depot in the cerebrospinal fluid. The approach presented is suggested as a basis for the development of lipid solutions that might prolong the duration of spinal analgesia produced by a single intrathecal injection.
Lipid and lipoprotein profiles relate to peak aerobic power in spinal cord injured men. The relationship between peak VO2 and serum lipids, lipoproteins, and apolipoproteins was assessed in nine traumatic spinal cord injured (SCI), active, male volunteers. Mean (SD) age, height, and weight were 30.6 (11.6) yr, 171.1 (11.3) cm, and 74.2 (12.5) kg, respectively. Peak VO2 (X = 2.13 l.min-1) was assessed by a graded arm-crank test to maximum, percent body fat (X = 28.7%) by densitometry, and lipid profile by measures of serum triglycerides, total cholesterol (TC), high and low density lipoprotein cholesterol (HDL-C and LDL-C, respectively), apolipoproteins (apoA-1, apoB), and various ratios of lipids, lipoproteins, and apolipoproteins. Significant inverse relationships emerged between peak VO2 and TC/HDL-C (r = -0.86; P less than 0.01), apoB/apoA-1 (r = -0.75; P less than 0.05), triglycerides (r = -0.73; P less than 0.05), and LDL-C/HDL-C (r = -0.72; P less than 0.05). Direct correlations (P less than 0.05) were demonstrated between peak VO2 and apoA-1/apoB (r = 0.71) and HDL-C/apoA-1 (r = 0.64). The present results indicate that, for active, mid-to-lower thoracic SCI men, the putative atherogenic and antiatherogenic lipid, lipoprotein, and apolipoprotein indices are significantly related to peak VO2 in a manner similar to that described for the able-bodied. These findings indicate the relevance of aerobic fitness assessment in planning CHD prevention strategies for the SCI.
Potentiating effect of ribavirin on the in vitro and in vivo antiretrovirus activities of 2',3'-dideoxyinosine and 2',3'-dideoxy-2,6-diaminopurine riboside. 2',3'-Dideoxyinosine (DDI) and 2',3'-dideoxy-2,6-diaminopurine riboside (ddDAPR) are potent and selective inhibitors of human immunodeficiency virus (HIV) replication in MT-4 cells. They are also inhibitory to the transformation of C3H/3T3 cells by Moloney murine sarcoma virus (MSV). In vivo, they are only marginally effective in delaying MSV-induced tumor formation, and mortality associated therewith in newborn NMRI mice. When combined with ribavirin, DDI and ddDAPR become much more effective in inhibiting MSV and HIV replication in vitro and MSV-induced tumor formation in vivo. These observations point to the potential role of ribavirin in potentiating the anti-HIV activity of DDI in AIDS patients.
Steroid-induced weakness in patients with primary brain tumors. Clinically significant steroid myopathy (SM) occurred in 23 (10.6%) of 216 adult patients with primary brain tumors who received 2 or more continuous weeks of daily dexamethasone therapy. SM occurred over a wide range of peak and cumulative doses of dexamethasone as well as a wide range of periods of continuous treatment. This was not an entirely random event, however, as two-thirds of the patients developed their weakness during the 9th through the 12th week of continuous dexamethasone treatment. The risk of developing SM was significantly lower in patients taking phenytoin than in patients who were not taking anticonvulsants. The only other patient or treatment factor associated with SM was a possible direct correlation with the appearance of a cushingoid body habitus. In this retrospective review, the occurrence of SM had a significant negative impact on the quality of life of all affected individuals. As expected, patients who tolerated a reduction in their steroid dose improved, while other patients suffered the combined effects of tumor progression and worsening myopathy. Substituting a nonfluorinated glucocorticoid for dexamethasone is probably advisable if neuro-oncology patients affected by SM cannot be weaned from the steroids.
GABA antagonism reverses hypoxic respiratory depression in the cat. We assessed the role of gamma-aminobutyric acid (GABA) as a potential causative agent of hypoxic respiratory depression by monitoring the response of the phrenic neurogram to systemic infusion of the GABA antagonist bicuculline (0.01 mg.kg-1.min-1) under control conditions and during isocapnic brain hypoxia produced by CO inhalation in separate groups of anesthetized, glomectomized, vagotomized, paralyzed, and ventilated cats with blood pressure held constant. The maximum effect of bicuculline in subseizure doses in control cats was to increase minute phrenic activity to 151 +/- 14% of preinfusion values. Infusion was continued until seizure activity was seen in the electroencephalogram. A 53% decrease of arterial O2 content resulted in a marked reduction of both peak phrenic amplitude and phrenic firing frequency to 16 and 64% of control values, respectively. Infusion of bicuculline while the level of hypoxia was maintained constant restored both peak phrenic amplitude and phrenic firing frequency to prehypoxic levels. The maximum effect of bicuculline was to increase minute phrenic activity to 123 +/- 13% of the prehypoxic value. These results suggest that although GABA has only a modest role in determining the output of the control phrenic neurogram, a significant portion of the phrenic depression that occurs during hypoxia can be attributed to inhibition of respiratory neurons by GABA.
Factor XI deficiency in Ashkenazi Jews in Israel. BACKGROUND AND METHODS. Severe factor XI deficiency, which is relatively common among Ashkenazi Jews, is associated with injury-related bleeding of considerable severity. Three point mutations--a splice-junction abnormality (Type I), Glu117----Stop (Type II), and Phe283----Leu (Type III)--have been described in six patients with factor XI deficiency. Clinical correlations with these mutations have not been carried out. We determined the relative frequency of the mutations and their association with plasma levels of factor XI clotting activity and bleeding, analyzing the mutations with the polymerase chain reaction and restriction-enzyme digestion. RESULTS. The Type II and Type III mutations had similar frequencies among 43 Ashkenazi Jewish probands with severe factor XI deficiency; these two mutations accounted for 49 percent and 47 percent, respectively, of a total of 86 analyzed alleles. Among 40 of the probands and 12 of their relatives with severe factor XI deficiency, patients homozygous for Type III mutation had a significantly higher level of factor XI clotting activity (mean [+/- SD] percentage of normal values, 9.7 +/- 3.8 percent; n = 13) than those homozygous for Type II mutation (1.2 +/- 0.5 percent, n = 16) or compound heterozygotes with Type II/III mutation (3.3 +/- 1.6 percent, n = 23), as well as significantly fewer episodes of injury-related bleeding. Each of these three groups had a similarly increased proportion of episodes of bleeding complications after surgery at sites with enhanced local fibrinolysis, such as the urinary tract, or during tooth extraction. CONCLUSIONS. Type II and Type III mutations are the predominant causes of factor XI deficiency among Ashkenazi Jews. Genotypic analysis, assay for factor XI, and consideration of the type and location of surgery can be helpful in planning operations in patients with this disorder.
Unilateral aortofemoral bypass: a safe and effective option for the treatment of unilateral limb-threatening ischemia. To determine whether unilateral aortofemoral (AUF) bypass is a safe and effective option for the treatment of unilateral limb-threatening ischemia in patients with aortic or bilateral iliac occlusive disease, we reviewed the results of 42 AUF bypasses performed using polytetrafluoroethylene grafts in patients operated on for limb salvage; 11 (26%) of the patients also underwent femoropopliteal or femorodistal (FP/D) bypasses. The indications for surgery were tissue necrosis or ulceration in 18 (43%) patients and rest pain in 17 (40%) patients. The 5-year primary graft patency and limb salvage rates for AUF bypass were 74% and 84%, respectively. The perioperative mortality rate was 5%. There were no significant differences in the primary graft patency or limb salvage rates in patients who underwent AUF bypass with or without FP/D bypass. Only 3 of 41 (7%) AUF bypass patients required subsequent femorofemoral bypass. We conclude that: (1) AUF bypass is a safe and effective surgical option in patients with unilateral limb-threatening ischemia and aortic or bilateral iliac occlusive disease; (2) the routine performance of an aortobifemoral or axillobifemoral bypass in patients with unilateral limb-threatening ischemia may be unnecessary; and (3) AUF bypass facilitates the combined inflow and infrainguinal operations that are frequently required for limb salvage in these patients.
Restricted V gene usage in T-cell lymphomas as detected by anti-T-cell receptor variable region reagents. Monoclonal antibodies reactive with variable regions of the human T-cell receptor (TCR) may be used to detect populations of T lymphocytes with restricted V gene usage. The authors have studied a series of 44 T-cell lymphomas with a panel of seven reagents reactive with four different TCR beta-chain variable region families. The authors found that, with this limited panel, restricted V gene usage of the neoplastic cells could be demonstrated in 29% of TCR-positive lymphomas. Whereas this is somewhat higher than expected, no preferential use of specific families could be demonstrated. An additional, unexpected finding was that most large cell T-cell lymphomas did not express TCR despite the presence of cytoplasmic CD3. The findings indicate that with a somewhat expanded panel it should be feasible to demonstrate restricted V gene usage as an indicator of clonality in a majority of T-cell lymphomas in a manner similar to the application of anti-immunoglobulin subclass antibodies in the diagnosis of clonal B cell proliferations.
Severe neurologic toxicity induced by cyclosporine A in three renal transplant patients. Cyclosporine A (CyA) is a potent immunosuppressive agent that is used in organ transplantation and in a variety of immunological diseases. It has a variety of adverse side effects, some of which can be serious and even life-threatening. CyA-associated neurotoxicity is generally mild, consisting of fine tremor. However, more complex neurologic abnormalities, including motor spinal cord and cerebellar syndromes, have rarely been described in bone marrow and liver transplant patients. Renal transplant patients have been spared from such CyA-induced toxicity. In this report, three renal transplant patients are described who developed complex and severe neurologic toxicity in the setting of therapeutic blood levels of CyA, which was completely reversible on discontinuation of the drug. No patient had a prior history of neurological or psychiatric dysfunction and there was no evidence of known psychoactive substance abuse. The toxicity was manifested as flaccid hemiparesis in one and dementia in a second patient. The third patient developed a previously unreported Guillain-Barre-like syndrome consisting of an ascending motor neuropathy. One patient developed reversible lesions involving the cerebral white matter. Whereas similar complex neurologic syndromes have been confined to patients who are intensely immunosuppressed, often debilitated, and have toxic levels of the drug, these three patients serve to emphasize that complex neurotoxicity can occur in stable patients who have therapeutic levels of CyA. Given the use of CyA in an ever-expanding list of disease processes, an appreciation of these potential neurologic syndromes is of paramount importance. At present, CyA-induced neurologic disease remains a diagnosis of exclusion.
The role of ultrasound in evaluation of patients with elevated maternal serum alpha-fetoprotein: a review. Accumulated experience with the sonographic detection of spina bifida and its associated fetal cranial changes indicates that nearly all these fetuses may be identified by ultrasound examination alone. A review of data from multiple centers shows that a complete and detailed, normal ultrasound is an appropriate basis for a reduction of at least 95% in the maternal serum alpha-fetoprotein (MSAFP)-based risk for neural tube defects. The use of this adjusted risk in patient counseling before amniocentesis may lower the rate of the procedure with no significant loss of diagnostic sensitivity. Among patients with elevated MSAFP, the rate of abnormal cytogenetic findings in fetuses with no abnormalities detected at ultrasound appears to be near 0.61%. Furthermore, the spectrum of abnormal cytogenetic results appears to differ from that associated with increased maternal age, in that the incidence of sex chromosome abnormalities is higher and that of Down syndrome is lower.