Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aggregate anaphylaxis was induced in eight ovalbumin-sensitized monkeys (Macaca irus). Hemodynamics, blood flow distribution and myocardial performance were studied. Following challenge, severe circulatory shock developed. Systemic arterial and left atrial pressures decreased and pulmonary arterial and right atrial pressures increased. There was a tenfold increase in pulmonary vascular resistance, and cardiac output was markedly reduced (-75%). A redistribution of the blood flow to vital organs (brain, heart and liver) occurred, at the expense of flow to other regions (muscles, kidneys, pancreas and spleen). There was also a redistribution of the blood flow within the myocardium, resulting in an unchanged right ventricular blood flow, despite a decrease in total myocardial blood flow. Right ventricular stroke work was reduced in spite of high filling pressures, whereas the decrease in left ventricular stroke work coincided with low filling pressures. It is concluded that the initial main cause of the low outflow state was an increased resistance in the pulmonary circulation followed by acute right heart failure.
 ...
PMID:Anaphylaxis in the monkey: hemodynamics and blood flow distribution. 11 76

To determine whether myocardial dysfunction contributes to vascular collapse in anaphylactic shock, we examined left ventricular (LV) contractility, coronary blood flow, and myocardial lactate metabolism during antigen challenge in eight dogs that were sensitized to ragweed pollen extract (anaphylaxis group). Findings in the anaphylaxis group were contrasted to those in another group of dogs in which mean blood pressure was decreased to the same extent by arteriolar vasodilation with nitroprusside. The animals were examined under nonhypoxic conditions while anesthetized and ventilated. LV mechanics were examined with subendocardial crystals placed primarily along the anterior-posterior minor axis of the LV. During antigen challenge, a depression in LV contractility was observed in the anaphylaxis group as assessed by fractional dimensional shortening, stroke volume, and the slope of the end-systolic pressure-dimension relationship. During anaphylaxis, moreover, coronary vasodilation rather than coronary vasoconstriction was observed, and evidence of myocardial ischemia as assessed by altered myocardial lactate metabolism was not found. Our results indicate that depressed LV contractility occurs in anaphylactic shock. The results further suggest that the mechanism may be due to a direct effect of mediators of anaphylaxis on the myocardium to produce systolic dysfunction.
 ...
PMID:Left ventricular contractility is depressed in IgE-mediated anaphylactic shock in dogs. 200 Sep 70

Thyrotropin-releasing hormone (TRH) has been shown to increase mean arterial pressure during anaphylactic shock. The hemodynamic mechanism of action and the effect of TRH on the respiratory system during anaphylactic shock are not known. A rabbit model of anaphylaxis was used to determine the effect of TRH, epinephrine (EPI), and normal saline (NS) on various cardiovascular and respiratory parameters during anaphylactic shock. Anaphylactic shock was induced by antigen challenge in 31 sensitized animals. After a 25% decrease in mean arterial pressure, they were randomly treated with TRH (2 mg/kg), EPI (0.005 mg/kg), or NS (10 mL/kg). Blood was drawn at baseline and at the end of the experiment for laboratory analysis. Cardiac and respiratory parameters were monitored continuously and measured at baseline, at onset of shock (time zero), and at time intervals for 30 minutes. Animals were treated with repeated doses during the first 15 minutes as needed to maintain mean arterial pressure above shock level. Five of ten TRH-, five of 11 EPI-, and six of ten NS-treated animals survived. The TRH-treated group required fewer doses than the other groups and had increased heart rate, mean arterial pressure, peripheral vascular resistance, respiratory rate, and minute ventilation as well as decreased stroke volume index and lung compliance compared with the NS-treated group. EPI treatment resulted in increased minute ventilation and decreased pulmonary airway resistance compared with NS treatment. The EPI group also had a higher postsurvival epinephrine level than the other groups. No difference in right atrial pressure, cardiac index, acid-base status, pO2, A- a gradient, lung weight, lactate, or norepinephrine levels was found.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Hemodynamic and respiratory effects of thyrotropin-releasing hormone and epinephrine in anaphylactic shock. 249 65

Platelet-activating factor (PAF) is a potent mediator of anaphylaxis and shock. In addition, evidence for PAF participation in gastric, intestinal and heart post-ischemic phase has been recently demonstrated. Ginkgo biloba extracts improve cerebral metabolism and protect brain against hypoxic damage in various models of cerebral ischemia. Potent and specific antagonists of PAF have been found in Ginkgo biloba and termed Ginkgolides: BN 52020, BN 52021, BN 52022, BN 52024. We therefore undertook the investigation of the role of Ginkgolides in cerebral ischemia obtained by bilateral ligature of the common carotid for 10 min and 6 h of recirculation in male Mongolian adult gerbils. Given preventively (one week treatment 10 mg/kg/day orally) or at the time of clamping, BN 52021 and related Ginkgolides dose-dependently antagonize morbidity assessed by the stroke-index. Similarly the mitochondrial respiration evaluated by the respiratory control ratio is significantly improved. In both determinations, the range of activity: BN 52021 greater than, BN 52020 greater than BN 52022 greater than BN 52024 shows that the effect of Ginkgolides in cerebral ischemia are correlated with their PAF antagonistic properties. Given curatively, 1 h after declamping, BN 52021 is able to reverse the cerebral impairment trend. Kadsurenone and brotizolam, two other chemically unrelated PAF antagonists led to similar recovery. Therefore PAF appears to play an important role in the post-ischemic phase after bilateral carotid ligation in Mongolian gerbils.
 ...
PMID:Involvement of platelet-activating factor (PAF) in cerebral post-ischemic phase in Mongolian gerbils. 343 53

Symptoms, therapy, and outcome of 49 cases of anaphylactic reaction are presented. Epinephrine (0.5-2.0 mg) did not produce any circulatory improvement but induced severe dysrhythmias and even ventricular fibrillation. Neither epinephrine nor prednisolone (2 g) prevented shock development, neurologic sequelae, or fatal outcome. Rapid infusion of 2000 ml 50% colloid (dextran 70 or starch, m.w. 450,000) with 50% Ringer's lactate, however, reliably restored circulation within 30 min. If elevated, airway resistance dropped in conjunction with colloid administration rather than with any other drug. Impairment of the pulmonary circulation is found to be the initial feature of anaphylaxis, manifested by a rise in pulmonary vascular resistance; then stroke volume and systemic blood pressure fall as left heart filling is reduced. Many findings indicate a high blood viscosity with resulting capillary occlusion: rapid clotting; low levels of factors I, II, V, VIII, and X; low plasma protein, which may be only 50% of its normal value; thrombocytopenia; and aggregation of white blood cells with fibrin in small lung vessels. Blood and plasma vanish from the circulation and appear to be sequestered in the pulmonary capillaries as the initial response to the antigen; later, the whole body is affected. Congestion and pain in the lymph nodes indicate that the lymphatic system may also become involved. On the basis of hemoconcentration, a blood volume deficiency in the range of 30% has been calculated.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Anaphylactic shock]. 360 58

Leukotriene D4, a constituent of slow-reacting substance of anaphylaxis, elicits a pressor response followed by hypotensive shock in spontaneously hypertensive rats but not in other rats. Hemodynamic mechanisms underlying this pattern in spontaneously hypertensive rats, pithed and vagotomized to eliminate circulatory reflexes, were studied using radiolabeled microspheres. One minute after leukotriene D4 administration (20 micrograms/kg i.v.), mean arterial pressure increased by 54 mm Hg, total peripheral resistance index increased by 68%, heart rate decreased by 34 beats/minute, and cardiac index was unchanged. Profound reductions of blood flow and increases of vascular resistance in the hepatosplanchnic area, skeletal muscles, and skin also occurred. Five minutes later, mean arterial pressure remained elevated (+35%), hematocrit rose (+17%), and total peripheral resistance index increased, which offset 40% decreases in cardiac and stroke volume indices. Ten minutes after leukotriene D4 administration, during hypotension, cardiac and stroke volume indices and blood flow to all vascular beds declined further while total peripheral resistance index and hematocrit (+28%) continued to rise. In Wistar-Kyoto rats, administration of leukotriene D4 caused less of a pressor response (+34 mm Hg) because vascular resistance was increased only in skeletal muscles, which was followed by a slight hypotension without any significant changes in cardiac and stroke volume indices, total or regional vascular resistance, and hematocrit. Thus, in spontaneously hypertensive rats the leukotriene D4-induced pressor response appears to be caused by generalized vasoconstriction, and the subsequent hypotension appears to result not from vascular collapse but from reduced cardiac output.
 ...
PMID:Overall and regional hemodynamic effects of leukotriene D4 in spontaneously hypertensive rats. 400 88

Over the January 1, 1979 to March 31, 1980 period sterilization-attributable deaths were identified in Dacca and Rajshahi Divisions, Bangladesh. These deaths were identified primarily through government records of compensation to families of deceased sterilization patients. This list was augmented by deaths reported from clinics of the Bangladesh Association for Voluntary Sterilization, detected through a prospective study of sterilization in Bangladesh, and identified by interviews with government family planning officials. A sterilization-associated death was defined as the death of a patient from any cause occurring within 42 days of tubal ligation or vasectomy. Death-to-case rates for vasectomy and tubal ligation were calculated for each month with 95% confidence intervals based on the Poisson distribution. 31 sterilization-associated deaths were identified over the study period. 28 of these were sterilization attributable and 3 were not. The mean age of the 21 women was 30.6 years, and their mean parity was 4.8. The mean age of the 7 vasectomy patients was 37.0 years. Abdominal Pomeroy method of tubal ligation was the only female sterilization technique used. 2 temporal clusters of sterilization attributable deaths occurred during the study. The 1st was a cluster of 5 deaths from tubal ligation performed in June 1979. 3 of these operations took place on June 5, 1979 but in different facilities. 1 factor common to each of these operations was the unseasonably hot weather. The 2nd temporal cluster consisted of 3 deaths after vasectomy in July 1979. 2 men from the same village died from scrotal infections after vasectomy on July 19, 1979 by the same surgeon at a single clinic. A similar death occurred earlier the same month. Another patient of the same surgeon and clinic associated with the deaths after operation on July 19 died from scrotal infection in January 1980. 3 vasectomy deaths related to 1 surgeon in a single remote facility suggests a breach of sterile technique. This could not be confirmed as this clinic physician could not be interviewed. The death-to-case rate for all procedures combined was 21.3 deaths/100,000 procedures, with the rate for vasectomy 1.6 times higher than that for tubal ligation. Anesthesia overdosage was the leading cause of death attributed to tubal ligation with tetanus (24%), intraperitoneal hemorrhage (14%), and infection other than tetanus (5%) as other leading causes. 2 patients (10%) died from pulmonary embolism after tubal ligation; 1 (5%) died from each of the following: anaphylaxis from anti-tetanus serum, heat stroke, small bowel obstruction, and aspiration of vomitus. All 7 men died from scrotal infections after vasectomy. Improvement in anesthesia management and sterile technique can lower the death-to-case rate for contraceptive sterilization in 2 Divisions of Bangladesh.
 ...
PMID:Sterilization-attributable deaths in bangladesh. 612 37

We investigated whether a nitric oxide synthase (NOS) inhibitor improves cardiovascular depression associated with anaphylaxis. After induction of anaphylactic circulatory depression, one group received an NOS inhibitor (Group I, n = 6) and the other received saline solution (Group II, n = 5). Mean arterial pressure and right atrial pressure were significantly higher in Group I than in Group II. Hematocrit was significantly lower in Group I than in Group II. Cardiac output, stroke volume, mean pulmonary arterial pressure, the maximum rate of increase in left ventricular pressure, and the time constant of the fall in isovolumic left ventricular pressure did not differ between the groups. In conclusion, L-NAME attenuates hypotension, but does not improve cardiac depression in anaphylaxis in dogs. Our finding that NOS inhibitor did not improve cardiac function implies that the production of NO in anaphylaxis may have a protective effect with regard to cardiac performance.
 ...
PMID:An inhibitor of nitric oxide synthase, N omega-nitro-L-arginine-methyl ester, attenuates hypotension but does not improve cardiac depression in anaphylaxis in dogs. 765 70

Stings by the imported fire ant almost always lead to dermal wheal and flare reactions followed by sterile pustules at sting sites. Less commonly, large local dermal reactions, pyoderma, anaphylaxis, or neuropathy may occur. Such reactions have previously been associated with contact with the insects out of doors. We present two previously unreported cases of indoor attacks on individuals by imported fire ants. One patient experienced a cerebrovascular accident in association with the attack, whereas the second patient had no obvious sequelae. With those two reports, a total of four such indoor massive sting episodes have appeared in the recent medical literature. Physicians and other individuals living in areas indigenous to the fire ant should be aware that infestation of buildings with fire ants may be associated with attacks on human beings indoors. Individuals with cognitive dysfunction seem to be especially at risk for attacks by fire ants.
 ...
PMID:Medical consequences of multiple fire ant stings occurring indoors. 818 26

Contrast-enhanced, high resolution, computed tomography (CT), along with gadolinium-enhanced magnetic resonance imaging (MRI), provide the skull-base surgeon with essential information for diagnosis and surgical planning. Evaluation of skull-base vasculature has traditionally been performed with angiography. Four-vessel angiography is an invasive procedure that subjects the patient to the potential risks of vascular injury, stroke, renal damage, anaphylaxis, and radiation. The development of gradient-recall echo pulse sequence in MRI provides a means to evaluate the vasculature with a noninvasive, low-risk technique. We review the experience of the House Ear Clinic with magnetic resonance angiography (MRA) in evaluating cranial-base abnormalities including paragangliomas, aberrant vessels, and dural sinus thrombosis. Based on a review of 25 cases, we conclude that MRA is a useful procedure for evaluation of major arteries, veins, and dural sinuses. The technique has been less helpful in defining small vessel detail such as feeding blood supply and tumor staining.
 ...
PMID:Magnetic resonance angiography: analysis of vascular lesions of the temporal bone and skull base. 842 77


1 2 3 4 Next >>