A novel neurotropic microsporidium from the swamp guppy Micropoecilia picta from Grenada, West Indies.

A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.

Intraperitoneal injection of sodium pentobarbital has the potential to elicit pain in adult rats (Rattus norvegicus).

An effective and pain-free killing method is required to achieve the goal of euthanasia, a "good death". Overdose of sodium pentobarbital (PB) by intraperitoneal (IP) injection is a widely accepted technique in laboratory rats, but questions remain regarding pain associated with administration. As PB rapidly causes sedation and loss of consciousness, most studies have relied on indirect evidence of pain. The objective of this study was to assess pain associated with IP PB using an appropriate vehicle control. Adult male and female Sprague Dawley (SD) and female Wistar rats (N = 84) were block randomised by sex and strain to receive one of three treatments: 1) 800 mg/kg PB (pH 11), 2) saline or 3) vehicle controls (pH 11 or 12.5). Behavior (Rat Grimace Scale (RGS), writhing, back arching) was evaluated at baseline, before loss of righting reflex (LORR, PB group), and at 80s, 151s and 10 min post-injection (PI; saline and vehicle control groups). In the PB group, mean time to LORR was 78 ± 7.9 seconds. In the vehicle control groups, RGS scores were increased at 151s PI (SD: p = 0.0002, 95%CI 0.73 to 0.20) from baseline, as was relative frequency of writhing (SD: p < 0.0001; Wistar; p = 0.0004). RGS scores remained elevated 10 mins PI (SD: p = 0.0005, 95%CI 0.71 to 0.18; Wistar: p = 0.0234, 95%CI 0.91 to 0.07) but the relative frequency of writhing did not (p > 0.999). The RGS scores and the relative frequency of writhing remained low in the PB and saline groups (p > 0.05). These results show that, vehicle controls for IP PB result in signs associated with pain, pain may not be experienced following IP PB when LORR occurs quickly, and that the effects of PB limit behavioral pain assessments.

[Peripheral arterial occlusive disease as predictor of high atherosclerotic burden]. / Periphere arterielle Verschlusskrankheit als Prädiktor einer hohen Atheroskleroselast.

Atherosclerosis is a disease which affects the whole arterial vascular tree. In particular patients with peripheral arterial occlusive disease (PAOD) often suffer from additional atherosclerotic manifestations in other vascular territories. This has a direct impact on cardiovascular prognosis. Atherosclerosis is an inflammatory disease. A high inflammatory burden is associated with polyvascular atherosclerosis and also with the occurrence of cardiovascular events. Control of cardiovascular risk factors is crucial for the treatment of patients with polyvascular atherosclerosis. In addition, anticoagulation treatment is very important in patients with atherosclerosis. Moreover, exercise training is an important treatment option in PAOD patients not only to improve walking distance but also for multiple additional positive effects. So far the role of anti-inflammatory treatment is not clear and must be further elaborated by future clinical research.

Forced-air pre-warming prevents peri-anaesthetic hypothermia and shortens recovery in adult rats.

General anaesthesia disrupts thermoregulation in mammals, which can cause hypothermia. Decreases in core body temperature of 1℃ cause significant postoperative complications in humans, and peri-anaesthetic hypothermia in mice increases data variability, which can potentially increase animal use. In rats, the impact of different temperature management strategies on the incidence and severity of hypothermia, and the accuracy of different temperature measurement methods, is unknown. Eighteen adult male and female SD rats were block-randomized to one of three treatment groups: no-warming (NW), limited-warming (LW, heat pad during anaesthesia), and pre-warming (PW, warm air exposure before anaesthesia, followed by heat pad). Anaesthesia (isoflurane) duration was for 40 min. Core body temperature (intra-abdominal telemetric temperature capsule) was recorded during anaesthesia and recovery. During anaesthesia, rectal, skin, and tail temperatures were also recorded. In the PW group, core temperature was maintained during anaesthesia and recovery. By contrast, the NW group was hypothermic (11% temperature decrease) during anaesthesia. The LW group showed a decrease in temperature during recovery. Recovery to sternal recumbency was significantly faster in the PW (125 [70-186] s, P = 0.0003) and the LW (188 [169-420] s, P = 0.04) groups than in the NW group (525 [229-652] s). Rectal temperature underestimated core temperature (bias -0.90℃, 95% limits of agreement -0.1 to 1.9℃). Skin and tail temperatures showed wide 95% limits of agreement, spanning 6 to 15℃, respectively. The novel strategy of PW was effective at maintaining core temperature during and after anaesthesia. Rectal temperature provided an acceptable proxy for core body temperature.

The relationship between the Rat Grimace Scale and mechanical hypersensitivity testing in three experimental pain models.

BACKGROUND: The assessment of facial expressions associated with pain has been used to evaluate pain in humans and has recently found application in non-human mammals. These so called 'grimace scales' have the potential to be developed into a widely accepted non-invasive method of measuring pain in laboratory rodents. Currently, common methodologies to assess pain rely on nociceptive tests that assess stimulus evoked withdrawal responses. These tests, however, are limited to the assessment of a reflexive response without an affective component. This study aimed to use the recently developed Rat Grimace Scale (RGS) and assess its relationship with a conventional nociceptive test (the application of von Frey filaments). METHODS: Fifty-two adult, male Wistar rats were randomized to one of five treatment groups: intraplantar carrageenan, intraplantar complete Freund's adjuvant (CFA), plantar incision, anaesthetic control and saline injection control. The RGS and response to mechanical hypersensitivity testing was evaluated at predetermined time points before and after treatment until withdrawal responses returned to baseline levels. RESULTS: The RGS score significantly increased in all pain models. The peak RGS score also coincided with the development of paw hypersensitivity. However, mechanical hypersensitivity persisted after RGS scores returned to baseline. CONCLUSION: This study confirms that the three pain models induce pain in rodents and showed that peak pain coincided with peak mechanical hypersensitivity. However, mechanical hypersensitivity remained once pain subsided, mimicking the human experience of CFA injection. These findings further our understanding of the roles of, and relationship between, these assays in the assessment of nociception and pain.

Cardiac risks in total hip replacement.

During total hip replacement, identifiable myocardial ischemia occurs intraoperatively, indicating myocardial strain. Coronary heart disease (CHD) patients are at risk during this type of surgery. Perioperatively, CHD patients had significantly longer ST depressions than patients not suffering from CHD (3348 min vs 454 min). The number of depression episodes was also significantly higher for CHD patients (160 vs 36). Comparing the perioperative with the postoperative stage demonstrated that CHD patients experienced a highly significant shift towards shorter periods of ST-segment depression postoperatively.

Bilocular atrial malignant mesenchymoma causing mitral and localized pulmonary vein flow obstruction: diagnosis by transoesophageal echocardiography.

Cardiac malignant mesenchymoma is an extremely rare malignancy with poor prognosis. We report a patient presenting with a history and clinical findings typical of mitral stenosis. Transthoracic echocardiography showed a mass on the thickened posterior mitral leaflet. Transoesophageal echocardiography revealed two tumoural masses: one on the atrial side of the posterior mitral leaflet causing mitral obstruction, the other arising in the region of the right lower pulmonary vein orifice and obstructing inflow through this vein.

A new technique to avoid suprarenal placement of Kimray-Greenfield filters: technical note.

A new technique that avoids suprarenal Greenfield filter placement was used in 2 patients with an inferior caval thrombus extending up to the renal veins. The caval thrombus was pulled down with the aid of a modified Dormia wire basket inserted via a transfemoral approach, while the Kimray-Greenfield filter was introduced from a transjugular approach and placed in an infrarenal position.

Combination of calcium channel blocker and thrombolytic therapy in acute myocardial infarction.

To evaluate the protective effect of nifedipine on ischemic myocardium, in addition to thrombolytic therapy, a total of 149 patients with acute myocardial infarction were included in a double-blind controlled study in which they received 20 mg sublingual nifedipine (74 patients in group 1) or placebo (75 patients in group 2) in the emergency ward, either intracoronary nifedipine, 0.2 mg before and 0.2 mg after reperfusion of the infarct-related vessel and 20 mg three times/day during the hospital stay, or placebo. Combined intravenous and intracoronary thrombolytic therapy was initiated by means of mechanical recanalization in nonreperfused vessels. There were no differences between group 1 and 2 with regard to age, sex, body weight, or location of infarct. Evolution of CK-MB release and cumulative CK-MB was higher in group 1 than in group 2. Changes with regard to regional and global left ventricular function and coronary anatomy were not significantly different (NS) between the two groups. Reocclusion occurred in 15 of 74 (20%) and 10 of 75 (13%) patients in groups 1 and 2, respectively. During the reperfusion period, second- and third-degree atrioventricular block occurred in 5.4% and 6.7% (NS), ventricular couplets in 17.6% and 24% (NS), ventricular tachycardia in 2.7% and 9.3%, and ventricular fibrillation in 2.7% and 8% of the patients, respectively. Mortality rates were 13% and 8%. The study demonstrates that even very early administration of nifedipine combined with intracoronary administration does not enhance the salvage of ischemic myocardium achieved by reperfusion.

[Results of PTCA following thrombolysis in acute myocardial infarct]. / Ergebnisse der PTCA nach Thrombolyse bei akutem Herzinfarkt.

The mortality in acute transmural myocardial infarction can be reduced by thrombolytic therapy administered within 6 hours after onset of symptoms. In patients with coronary angiography proven stenosis of less than 70% conservative therapy is recommended. In patients with one vessel disease PTCA in patients with suitable lesions should be used. Further studies have to elucidate, if the angioplasty has to be performed in the acute stage or on an elective basis. PTCA is recommended in patients with occluded coronary vessels and in patients with high grade stenosis and limited coronary blood flow. In patients with multi vessel disease aortocoronary bypass surgery is recommended to reduce high mortality. Long-term results demonstrate, that patients in whom PTCA or coronary bypass surgery was performed demonstrated the highest survival rate.

[Local fibrinolytic therapy of vascular occlusions in the pelvic-leg area and the upper extremity]. / Lokale Fibrinolysetherapie von Gefässverschlüssen im Becken-Bein-Bereich und der oberen Extremität.

Seventy-three patients with vascular occlusions in the pelvis or lower limbs and three patients with upper limb lesions were treated by local low dose fibrinolysin, with strict control of any possible bleeding tendencies. Adequate recanalisation was obtained in 56 patients (73.6%). In ten patients, the occlusion recurred while the patient was still in hospital. After four to six months, 37 of the 56 (67%) of the vessels were still patent. In 18 patients, peripheral emboli resulted in some deterioration, but in 15 of these cases this could be treated successfully by operation. The methods and indications of local fibrinolysis therapy and the problems associated with it are discussed.

Balloon coronary angioplasty in patients with acute myocardial infarction.

After successful thrombolysis, approximately 75% of all patients will have significant coronary stenosis, which can be dilated by means of percutaneous transluminal balloon angioplasty (PTCA). In a randomized control study, 95 of our patients (Group I) had thrombolysis alone, whereas 95 others (Group II) had thrombolysis and PTCA. Both groups were comparable with respect to age, sex, infarct location, and maximal creatine kinase (CK) value. The clinical outcome during the hospital phase was better in Group II, which had a reocclusion rate of 13%, a reinfarction rate of 5%, a lethal reinfarction rate of 2%, and a cardiac death rate of 7%, compared with respective rates of 20%, 13%, 7%, and 13% in Group I. Furthermore, in Group I, residual coronary stenosis immediately after thrombolysis (75% +/- 20%) did not improve significantly until the end of the hospital phase, when it decreased to 69% +/- 21%. In Group II, stenosis (78% +/- 16%) was improved by PTCA to 33% +/- 21%, and this improvement remained constant during the hospital phase (30% +/- 26%). In Group-II patients who had an unsuccessful PTCA, stenosis was approximately the same before dilatation (83% +/- 12%), after dilatation (80% +/- 17%), and at the control study (83% +/- 17%). The end-diastolic, end-systolic, and stroke volume indices, as well as the ejection fraction, also remained unchanged. In Group I, the number of pathologic wall segments (12.2 +/- 5.0) did not improve during the hospital phase (12.2 +/- 7.9), but in Group II, the improvement was significant (14.0 +/- 5.7 vs. 10.9 +/- 8.2) (p < 0.05). PTCA seems to improve the clinical outcome, reduce the infarction and mortality rates, and enhance myocardial perfusion and performance.

Percutaneous transluminal coronary angioplasty after thrombolytic therapy: a prospective controlled randomized trial.

In 162 patients with acute transmural myocardial infarction, combined intravenous and intracoronary thrombolytic therapy with streptokinase was initiated. In vessels that remained occluded, mechanical recanalization was performed with a 3F recanalization catheter (group I, n = 79) or a 4F Grüntzig balloon catheter (group II, n = 83). After reperfusion, intracoronary streptokinase was administered superselectively. After termination of streptokinase infusion, angioplasty was performed only in patients in group II. There was no difference between the groups in relation to sex, age, infarct location, creatine kinase levels and time between onset of symptoms and start of treatment. Initial coronary angiography showed an open vessel in 27 (34%) of 79 patients in group I and 21 (25%) of 83 patients in group II. The final reperfusion rate was 90% (71 of 79) in group I and 86% (71 of 83) in group II. Angioplasty was attempted in 69 of the 71 patients in group II with a success rate of 65% and an occlusion rate of 3%. During the hospital stay, reocclusion occurred in 14 (20%) of 71 patients in group I. After thrombolytic therapy, coronary luminal narrowing in group I was 75 +/- 17% in patients without and 87 +/- 6% in patients with reocclusion (p less than 0.05). In group II, reocclusion was found in 10 (14%) of 71 patients. After angioplasty, the degree of coronary stenosis in group II was reduced from 82 +/- 12 to 51 +/- 30% (p less than 0.001). Reocclusion was found in 3 (7%) of the 45 patients with successful angioplasty and in 7 (32%) of the 22 patients with unsuccessful angioplasty (p less than 0.01). Improvement in regional left ventricular function was observed only in patients from group II with anterior myocardial infarction. In conclusion, by combined medical and mechanical recanalization, the rate of coronary reperfusion can be increased and infarct time shortened, providing the possibility of full revascularization by angioplasty, with improvement of regional wall motion and reduction of the rate of reocclusion.

[Combined use of thrombolysis and PTCA in myocardial infarct. Effect on global and regional ventricular function]. / Kombinierte Anwendung von Thrombolyse und PTCA bei Myokardinfarkt. Einfluss auf die globale und regionale Ventrikelfunktion.

The study was performed to evaluate the combined effect of thrombolysis therapy and percutaneous coronary transluminal angioplasty (PTCA) on global and regional left ventricular function. In 127 patients with acute transmural myocardial infarction combined intravenous (250 000 U) and intracoronary (50 000 U) streptokinase therapy was started. When the infarct related vessel was occluded mechanical recanalization was performed with recanalization by Gruentzig balloon catheters. Patients were randomized in two groups, group I, n = 64, thrombolysis without PTCA; group II, n = 63, thrombolysis with PTCA. Both groups demonstrated no difference in relation to sex, age, infarct location, as well as CPK levels and time between onset of symptoms and start of treatment. First coronary angiography showed an open vessel in 23/64 patients (36%) of group I and in 12/63 patients (19%) of group II (p less than 0.001). Mechanical recanalization with 3 F catheters could be achieved in 27/41 patients (66%) of group I and with 4 F catheters in 26/51 patients (51%) of group II. In 9/41 patients (22%) of group I and in 18/51 patients (35%) in group II reperfusion took place before mechanical recanalization could be performed or occurred during superselective thrombolysis therapy, when mechanical recanalization failed. Thus, reperfusion rate in group I was 59/64 patients (92%) and in group II 56/63 patients (89%). PTCA was attempted in 55/56 patients in group II with a success rate of 65% and reocclusion rate of 4%. During hospital stay, reocclusion occurred in 10/59 patients in group I (17%) and in group II in 9/55 patients (16%). The patients were divided in those with and without successful angioplasty. Reocclusion was found in 3/36 patients (8%) and 6/17 patients (35%), respectively. Improvement with PTCA of regional and global left ventricular function was observed in patients with anterior myocardial infarction. With combined medical-mechanical recanalization, reperfusion rate can be increased and infarct time shortened, thus, providing the possibility of full revascularization by PTCA, improving coronary blood flow as well as improving global and regional left ventricular function.

[PTCA and intracoronary lysis in acute myocardial infarct]. / PTCA und intrakoronare Lyse bei akutem Myokardinfarkt.

In 76% of all patients in whom thrombolysis was successful a residual stenosis exceeding 75% luminal diameter was found. Some patients suffered from single, others from multi-vessel disease. In single vessel diseases immediate intracoronary balloon dilatation of the residual stenosis is feasible. In multi-vessel diseases an aortocoronary bypass operation may follow. In a non-randomized study of 411 patients treated successfully with thrombolysis the best prognosis during the hospital phase and the subsequent 12 months was found in those who had had bypass surgery; patients treated with PTCA had the next best prognosis, and those treated with medical therapy had the worst. In a randomized study 95 patients were treated with thrombolysis alone and another 95 patients with thrombolysis plus immediate PTCA. PTCA diminished the degree of stenosis significantly (78 +/- 16% vs. 33 +/- 21%; p less than 0.001). This value remained constant during the following four weeks (30 +/- 26%). The clinical course, segmental wall motion and myocardial perfusion were more favourable in the PTCA group. No differences were found regarding spontaneous and inducible ventricular electrical vulnerability. Immediate PTCA without prior thrombolysis was performed in 27 patients with overt cardiogenic shock. The clinical mortality was significantly lower than in comparative studies. Recanalisation was successful in 24 of 27 patients. PTCA is complementary to successful thrombolysis in acute myocardial infarction to improve the prognosis and myocardial perfusion.

The serum selenium concentration of patients with acute myocardial infarction.

Serum selenium concentration was determined in 49 patients with acute myocardial infarction within 4 hours after the beginning of the symptoms. The mean serum selenium concentration of the patients was significantly lower than that of healthy controls (55 +/- 15 micrograms/l vs. 78 +/- 11 micrograms/l). Among the 49 patients with acute myocardial infarction 20 (41%) had serum selenium concentration below the 95% percentile of the healthy control group. It is concluded that the low serum selenium concentration was present in these patients before the acute event and was not a consequence of the myocardial infarction. No relationship was found in this study between the serum selenium concentration and the severity of myocardial infarction if the number of coronary vessels occluded is taken as the criterion of severity. Serum selenium concentration was similar in patients with 1 or more coronary vessels occluded. Patients with anterior or posterior myocardial infarction had similar serum selenium concentrations. A positive correlation was observed between serum selenium concentration and total serum creatine kinase (CK) activity and serum myoglobin (MB). The serum selenium concentration correlated negatively with the ratio CK-MB/total CK activity, which can be interpreted as minor injury of mitochondria during infarction in patients with normal serum selenium concentration.

Supernormal conduction in the right bundle branch: lack of influence of autonomic blockade.

A programmed atrial stimulation at a driving rate of 100/min was performed in a 47-year-old woman with left bundle branch block. Supernormal conduction lasting 40 ms was revealed within the right bundle branch. After autonomic blockade (0.2 mg propranolol/kg body weight and 0.04 mg atropine/kg body weight) the position and duration of the supernormal conduction did not change. This suggests that the autonomic nervous system has no influence on the supernormal phase of conduction in the human intraventricular conduction system.

Blood volume following diuresis induced by furosemide.

Changes in blood volume were investigated following intravenous injection of a single dose of furosemide in 21 patients with pulmonary edema. In a subset of 10 patients in whom the blood urea nitrogen level was 11.4 +/- 2.2 mg/dl and the serum creatinine level was 1.3 +/- 0.1 mg/dl and in whom total urine output exceeded 1 liter over a four- to six-hour interval ("diuretic" group), no significant change in plasma or total blood volume was observed, nor were there any significant changes in hematocrit. In a "nondiuretic" group of 11 patients who had moderately decreased renal function (blood urea nitrogen level 59.3 +/- 13.0 mg/dl and serum creatinine level 2.3 +/- 0.3 mg/dl) and in whom total urine output was less than 1 liter over the four- to six-hour interval, there was a significant increase in blood volume with a concomitant decrease in hematocrit and hemoglobin levels. Furosemide-induced diuresis therefore did not deplete intravascular volume. To the contrary, actions of furosemide that were independent of its diuretic action were associated with an expansion of plasma volume in the absence of diuresis. This may be related to the venous capacitance effects of furosemide with lowering of venous resistance and, therefore, lowering of the capillary hydrostatic pressure. In addition, there was an increase in colloid osmotic pressure. Both mechanisms increase the effective oncotic pressure gradient, which favors reabsorption of extravascular (edema) fluid. It is concluded that intravascular volume was therefore replenished at a rate equal to or in excess of the volume removed by diuresis.

Application of impedance cardiography in critical care medicine.

In spite of good correlations between cardiac output measurements by impedance and established invasive procedures (dye- and thermo-dilution) reported by numerous authors it is doubtful uptil now whether calculations of stroke volume according to the formula of Kubicek et al. (1974) can provide absolutely reliable results. The origin of the dz/dt curve and influencing factors of impedance wave have to be cleared up prior to the total acception of impedance cardiography as a reliable method for determining non-invasive stroke volume. This is true in spite of the agreement of all authors we know, that the reproducibility of the impedance cardiography values is as good as in dye or thermo-dilution measurements. However, for patient monitoring it is sometimes more important to assess the relative changes in stroke volume than to measure its absolute value. For long-term non-invasive monitoring of myocardial contractility in critically ill patients or after pharmacological interventions impedance cardiography may be recommended. Besides systolic time intervals, such as pre-ejection time and ventricular ejection time, three more reliable parameters can be derived from the first derivate of impedance wave. Impedance plethysmography has been shown as a reliable method to diagnose deep vein thrombosis and good correlations between impedance and strain-gauge plethysmography and phlebographic findings are reported. In addition fluid volume changes in the leg, venous capacity, venous outflow and arterial inflow may be determined by impedance plethysmography in a simple way. There is no doubt that alterations in the fluid content of biological tissue may measured by impedance technique. However, correlations between changes in the transthoracic impedance and fluid content of the thorax can be quantified only in a single subject which serves as its own control. Overall standardization is not possible. The reason for interindividual differences in the thoracic impedance at a given reduction of body water are due to anatomical differences, intrapulmonary air volume and pressure, location of the electrodes, electrical conductivity of the tissue and, above all, due to the position of the body. Therefore if transthoracic impedance is determined sequentially measurements must be performed with special attention to the position of the body to get reproducible results. Rapid infusion of colloids or blood transfusion may decrease transthoracic impedance due to intravascular volume expansion even at a net fluid lost during forced furosemide-induced diuresis or extracorporal hemodialysis.(ABSTRACT TRUNCATED AT 400 WORDS)