Biomphalaria obstructa (Morelet, 1849): a study of topotypic specimens (Mollusca: pulmonata: planorbidae)

A description of Biomphalaria obstructa (Morelet, 1849), based on specimens collected at its type locality - isla del carmen, state of Campeche, Mexico - is presented. The Shell is small, 13 mm in diameter, 3.5 mm in width and with 5.75 whorls in the largest specimen, thin, moderately lustrous and translucent, horn-colored. Whorls increasing regularly (neither slowly nor rapidly) in diameter, rounded on the periphery side, bluntly angular on the left. Suture well-marked, deeper on the left. Right side widely concave, with first whorl deeply situated and partly hidden by the next. Left side shallower than right one, largely flattened, with first whorl plaintly visible. Aperture roundly heart-shaped, usually in the same plane as the body whorl but somewhat deflected to the left (less frequently to the right) in some specimens. Peristome sharp, seldom blunt; a distinct callus on the parietal wall. A number of young shells develop one set (seldom more) of apertural lamellae which tend to be resorbed as the shell grows. Absence of renal ridge. Ovotestis with about 70 mostly unbrached diverticula. Seminal vesicle beset with well-developed knoblike to fingerlike diverticula. Vaginal pouch more or less developed. Spermatheca club-shaped when empty, egg-shaped when full, and with intermediate forms between those extremes. Spermathecal body usually somewhat longer than the duct. Prostate with 7 to 20 (mean 12.06 ± 2.51) usually short diverticula which give off plumpish branches spreading out in a fan shape and overlapping to some extent their immediate neighbors. Foremost prostatic diverticulum nearly always partially or completely inserted between the spermathecal body and the uterine wall. Penial sheath consistently narrower and shorter than the prepuce. Muscular coat of the penis consisting of an inner longitudinal and an outer circular layers. Ratios between organ lengths: caudal to cephalic parts of female duct = 0.55 to 1.37 (mean 0.85 +- 0.17); cephalic parte of female duct to penial complex = 1.36 to 2.81 ((mean 1.90 +- 0.33); penial sheath to prepuce = 042 to 0.96 (mean 0.67 +- 0.13). Comparison with Morelet’s type specimens of Planorbis orbiculus and P. retusus points to the identity of those nominal species with B. obstructa.

Mental rotation of anthropoid hands: a chronometric study

It has been shown that mental rotation of objects and human body parts is processed differently in the human brain. But what about body parts belonging to other primates? Does our brain process this information like any other object or does it instead maximize the structural similarities with our homologous body parts? We tried to answer this question by measuring the manual reaction time (MRT) of human participants discriminating the handedness of drawings representing the hands of four anthropoid primates (orangutan, chimpanzee, gorilla, and human). Twenty-four right-handed volunteers (13 males and 11 females) were instructed to judge the handedness of a hand drawing in palm view by pressing a left/right key. The orientation of hand drawings varied from 0º (fingers upwards) to 90º lateral (fingers pointing away from the midline), 180º (fingers downwards) and 90º medial (finger towards the midline). The results showed an effect of rotation angle (F(3, 69) = 19.57, P < 0.001), but not of hand identity, on MRTs. Moreover, for all hand drawings, a medial rotation elicited shorter MRTs than a lateral rotation (960 and 1169 ms, respectively, P < 0.05). This result has been previously observed for drawings of the human hand and related to biomechanical constraints of movement performance. Our findings indicate that anthropoid hands are essentially equivalent stimuli for handedness recognition. Since the task involves mentally simulating the posture and rotation of the hands, we wondered if "mirror neurons" could be involved in establishing the motor equivalence between the stimuli and the participants' own hands.

Autonomic control of cardiorespiratory interactions in fish, amphibians and reptiles

Control of the heart rate and cardiorespiratory interactions (CRI) is predominantly parasympathetic in all jawed vertebrates, with the sympathetic nervous system having some influence in tetrapods. Respiratory sinus arrhythmia (RSA) has been described as a solely mammalian phenomenon but respiration-related beat-to-beat control of the heart has been described in fish and reptiles. Though they are both important, the relative roles of feed-forward central control and peripheral reflexes in generating CRI vary between groups of fishes and probably between other vertebrates. CRI may relate to two locations for the vagal preganglionic neurons (VPN) and in particular cardiac VPN in the brainstem. This has been described in representatives from all vertebrate groups, though the proportion in each location is variable. Air-breathing fishes, amphibians and reptiles breathe discontinuously and the onset of a bout of breathing is characteristically accompanied by an immediate increase in heart rate plus, in the latter two groups, a left-right shunting of blood through the pulmonary circuit. Both the increase in heart rate and opening of a sphincter on the pulmonary artery are due to withdrawal of vagal tone. An increase in heart rate following a meal in snakes is related to withdrawal of vagal tone plus a non-adrenergic-non-cholinergic effect that may be due to humoral factors released by the gut. Histamine is one candidate for this role.

Protective effect of left ventricular hypertrophy in right coronary artery occlusions

OBJECTIVE: To test the hypothesis that left ventricular hypertrophy (LVH) reduces the electrocardiographic and functional effects of right coronary artery occlusion. METHODS: We analysed 215 patients (166 males and 49 women,age of 58.9±10.6 years), with occlusion of the right coronary artery without other associated lesions. There was no significant difference (p>0.05) in age and gender distribution between the 78 patients with LVH (left ventricular mass >100g/m²) (Group A) when compared with the 137 patients without LVH (left ventricular mass <100g/m²) (Group B). RESULTS: The electrocardiographic finding of transmural necrosis was more often found in group B patients than in group A patients (56.9% and 30.8%, respectively; p<0.05). The left ventricular function parameters of group A were better than those of group B: the ratio end-diastolic pressure/systolic pressure (EDP/SP) (A: 0.108±0.036; B: 0.121±0.050; p<0.05); the end-diastolic volume index (A: 75.9±31.3ml/m²; B: 88.0±31.0ml/m²; p<0.01); the end-systolic volume index (A: 16.0±10.0ml/m²; B: 27.0 ±20.0ml/m²; p<0.001); the ejection fraction (A 78.6±10.8%; B 67.7±17.9%; p<0.001); the anteroinferior shortening (A: 43.9±10.3%; B: 35.1±12.8%; p<0.001). A higher degree of coronary tortuosity was observed in group A than in group B (78.2% and 24.1%; p<0.001) and also a more frequent absent or minimal diaphragmatic hypokinetic area (A: 80.8%; B: 54.0%; p<0.05). CONCLUSION: LVH reduces the effects of myocardial sequela and protects LV function when right coronary occlusion develops.

Comparison between right and left ventricular myocardia during the human fetal period. Stereological evaluation

PURPOSE: To develop a stereological comparison between right (RV) and left ventricle (LV) myocardium during the third human gestational trimester. METHODS: Five human fetal hearts of the third trimester provided representative samples of 5 RV myocardium and 4 LV myocardium. The material was fixed in 10% buffered formaldehyde, and processed through routine methods. Fifteen microscopic fields were randomly chosen and counted in each ventricular myocardium using an "M-42" test system. The following stereological parameters were assessed: Vv (%), Lv (µm²), Sv (µm²/µm³), Vp (µm³), Nv (1/mm³) and total N. RESULTS: No significant difference between the stereological parameters of the myocardial structures assessed was evidenced, when comparing RV and LV. CONCLUSION: Right and left human ventricular myocardium are very similar during the fetal period at least in regard to their structural aspects.

Anomalous origin of the left coronary artery from the right pulmonary artery with intramural aortic trajectory. Clinicosurgical diagnostic implications

OBJECTIVE: Anomalous origin of the left coronary artery from the right pulmonary artery (AOLCARPA), is a rare entity that is usually associated with other defects. Of the 20 cases of AOLCARPA reported in the literature, 14 (70%) had associations. We describe four patients with AOLCARPA without associated defects, but with a peculiar intramural aortic trajectory. METHODS: Fifty-five patients with anomalous origin of the left coronary artery were operated upon at INCOR-FMUSP. Four of the patients had the anomalous origin from the right pulmonary artery (RPA) without associated defects but with intramural aortic trajectory. Clinical and laboratory examinations were analyzed, as well as surgical findings. RESULTS: All patients had congestive heart failure (CHF) and 3 also had angina pectoris. Two patients had a murmur of mitral regurgitation, signs of myocardial infarction on the ECG and cardiomegaly. The shortening fraction varied from 9% to 23%. The hemodynamic study confirmed the diagnosis of anomalous origin of the coronary artery, but the intramural trajectory and the origin from the RPA were established only at surgery. In 3 patients, the technique of side-to-side anastomosis was performed with a good outcome. One patient, who underwent end-to-side anastomosis, died 6 months after the surgery. CONCLUSION: Association with other defects usually occurs in the AOLCARPA, and the intramural aortic trajectory is difficult to clinically diagnose but easy to surgically correct.

Double outlet right ventricle with anterior and left-sided aorta and subpulmonary ventricular septal defect

Double outlet right ventricle (DORV) is a heterogeneous group of abnormal ventriculoarterial connections where, by definition, both great arteries (pulmonary artery and aorta) arise primarily from the morphologically right ventricle. This condition affects 1-1.5% of the patients with congenital heart diseases, with a frequency of 1 in each 10,000 live births. We report the case of an 18-day-old infant with DORV and extremely rare anatomical features, such as anterior and left-sided aorta and subpulmonary ventricular septal defect (VSD). In addition to the anatomic features, the role of the echocardiogram for guiding the diagnosis and the surgical therapy of this congenital heart disease are discussed.

The stability of right- and left-handed alpha-helices as a function of monomer chirality

Poly-L-alanine forms stable right-handed alpha-helices, whereas Poly-D-alanine is stable as left-handed alpha helices.

Comparative efficacy and safety of the left versus right radial approach for percutaneous coronary procedures: a meta-analysis including 6870 patients

The radial approach is widely used in the treatment of patients with coronary artery disease. We conducted a meta-analysis of published results on the efficacy and safety of the left and right radial approaches in patients undergoing percutaneous coronary procedures. A systematic search of reference databases was conducted, and data from 14 randomized controlled trials involving 6870 participants were analyzed. The left radial approach was associated with significant reductions in fluoroscopy time [standardized mean difference (SMD)=-0.14, 95% confidence interval (CI)=-0.19 to -0.09; P<0.00001] and contrast volume (SMD=-0.07, 95%CI=-0.12 to -0.02; P=0.009). There were no significant differences in rate of procedural failure of the left and the right radial approaches [risk ratios (RR)=0.98; 95%CI=0.77-1.25; P=0.88] or procedural time (SMD=-0.05, 95%CI=0.17-0.06; P=0.38). Tortuosity of the subclavian artery (RR=0.27, 95%CI=0.14-0.50; P<0.0001) was reported more frequently with the right radial approach. A greater number of catheters were used with the left than with the right radial approach (SMD=0.25, 95%CI=0.04-0.46; P=0.02). We conclude that the left radial approach is as safe as the right radial approach, and that the left radial approach should be recommended for use in percutaneous coronary procedures, especially in percutaneous coronary angiograms.

One-year cardiac morphological and functional evolution following permanent pacemaker implantation in right ventricular septal position in chagasic patients

INTRODUCTION: The septal position is an alternative site for cardiac pacing (CP) that is potentially less harmful to cardiac function. METHODS: Patients with Chagas disease without heart failure submitted to permanent pacemaker (PP) implantation at the Clinics Hospital of the Triângulo Mineiro Federal University (UFTM), were selected from February 2009 to February 2010. The parameters analyzed were ventricular remodeling, the degree of electromechanical dyssynchrony (DEM), exercise time and VO2 max during exercise testing (ET) and functional class (NYHA). Echocardiography was performed 24 to 48h following implantation and after one year follow-up. The patients were submitted to ET one month postprocedure and at the end of one year. RESULTS: Thirty patients were included. Patient mean age was 59±13 years-old. Indication for PP implantation was complete atrioventricular (AV) block in 22 (73.3%) patients and 2nd degree AV block in the other eight (26.7%). All patients were in NYHA I and no changes occurred in the ET parameters. No variations were detected in echocardiographic remodeling measurements. Intraventricular dyssynchrony was observed in 46.6% of cases and interventricular dyssynchrony in 33.3% of patients after one year. CONCLUSIONS: The findings of this work suggest that there is not significant morphological and functional cardiac change following pacemaker implantation in septal position in chagasic patients with normal left ventricular function after one year follow-up. Thus, patients may remain asymptomatic, presenting maintenance of functional capacity and no left ventricular remodeling.

Kidney function after left renal vein ligation in the dog

The ligature of the left renal vein is an alternative whenever this vessel is injured. The purpose of this study was to evaluate the capacity of the affluents of the left renal vein, proximal to the ligature, to maintain tissue vitality and function of the left kidney. Fifteen mongrel male dogs were divided in 3 groups of 5 dogs: Group I (control) - a laparotomy was performed, and the abdominal structures were only identified; Group II - the left renal vein was tied, close to vena cava; Group III - the same procedure as for Group II and a right nephrectomy. Blood urea nitrogen and serum creatinine levels were measured before the procedure, and every 3 days during 4 weeks in the postoperative period. Renal arteriography and an excretory urogram were performed on the animals that survived 60 days. Thereafter, or immediately after precocious death, the kidneys were removed for histological examination. All the animals of Group III died before two months (mean = 10.5 +-3.2 days), while the animals of Group II survived during that period. There was a complete exclusion of the left kidney in all dogs that underwent renal vein ligature. In the animals of Group II, the renal cortico-medullary limits could not be identified. At microscopy, the aspect was suggestive of nephrosclerosis. In the animals of Group III, the left kidney was enlarged, and a great amount of intravascular and intrapelvic blood clots were observed. At microscopy, extensive areas of necrosis, inflammatory infiltration, and hemorrhage were identified. In conclusion, the tributaries of the renal vein were not sufficient to maintain the tissue vitality and function of the left kidney after ligature of its main vein.

Right ventricular bifocal stimulation in the treatment of dilated cardiomyopathy with heart failure

OBJECTIVE: To describe a new more efficient method of endocardial cardiac stimulation, which produces a narrower QRS without using the coronary sinus or cardiac veins. METHODS: We studied 5 patients with severe dilated cardiomyopathy, chronic atrial fibrillation and AV block, who underwent definitive endocardial pacemaker implantation, with 2 leads, in the RV, one in the apex and the other in the interventricular septum (sub pulmonary), connected, respectively, to ventricular and atrial bicameral pacemaker outputs. Using Doppler echocardiography, we compared, in the same patient, conventional (VVI), high septal ("AAI") and bifocal ("DDT" with AV interval ~ 0) stimulation. RESULTS: The RV bifocal stimulation had the best results with an increase in ejection fraction and cardiac output and reduction in QRS duration, mitral regurgitation and in the left atrium area (p <= 0.01). The conventional method of stimulation showed the worst result. CONCLUSION: These results suggest that, when left ventricular stimulation is not possible, right ventricular bifocal stimulation should be used in patients with severe cardiomyopathy where a pacemaker is indicated.