Anatomic features of the interventricular septum in persistent atrioventricular canal

Twenty-two preparations of hearts with preserved atrioventricular canal have been investigated. Primary defect of the interatrial septum is a constant component of this pathological state. The size of the defect defines participation of the atria in formation of the atrioventricular canal. At the same time it is possible to distinguish the following anatomical varieties of abnormal development of the interatrial septum; oblique cleft in the oval fossa, partial absence of the valve in the oval orifice, perforation of the valve in the oval orifice, complete absence of the valve in the oval orifice and certain defects of the interatrial septum situating beyond the oval fossa limits.     

Chordoid glioma of the third ventricle: Report of a case with cytologic features and utility during intraoperative consultation

BACKGROUND: Chordoid glioma is a rare, low grade neoplasm with a unique chordoid appearance as well as distinct clinicopathologic and immunohistochemical features. Its cytologic features have not been described. CASE: A 42-year-old woman with recent-onset amnesia and confusion underwent magnetic resonance imaging, which revealed a 5-cm mass lesion arising in the third ventricle. Intraoperative squash smears showed cellular sheets as well as nests and strands of epithelioid tumor cells with bland nuclei and polygonal to elongated cytoplasm in a mucinous background. Binucleation was commonly seen. The tumor was intimately admixed with a benign lymphoplasmacytic infiltrate and scattered Russell bodies. Histologically, the tumor cells were arranged in a syncytium with prominent lymphoplasmacytic infiltrates and scattered small foci of necrosis in a mucinous matrix. The foremost differential diagnosis was chordoid meningioma. Immunohistochemically, the tumor cells were positive for glial fibrillary acid protein (GFAP), vimentin, epithelial membrane antigen, CD34, neuron-specific enolase and CK-7 and negative for synaptophysin, S-100 protein, neurofilament, and estrogen and progesterone receptors. CONCLUSION: Intraoperative smear cytology in this case of chordoid glioma revealed distinctive cytologic features, reflecting the unique histologic pattern. Cytologic features, such as binucleation, absence of intranuclear pseudoinclusions and GFAP immunoreactivity, are particularly helpful in differentiating chordoid glioma from chordoid meningioma.     

Investigation of the possibility of solitary waves in the base stacks of DNA.

The possibility of the existence of solitary waves in DNA is investigated. On the basis of our classical model we do not find such a wave in a polynucleotide, but for a stack of adenine molecules without backbone we observe one. Possible extensions of the model for DNA are discussed. From our results we can conclude, that solitons exist in stacked systems without an additional backbone. At least the degree of freedom which couples a nucleotide base (pair) to the sugar-phosphate backbones (N-C stretching vibration) has to be treated with the help of the quantum equations of motion.     

Electrical and mechanical effects induced by cold temperatures in the ventricle of isolated Rana ridibunda hearts

A temperature decrease changes the contractility of the amphibian heart, but the underlying mechanisms are not totally understood. The objectives of the present work were to better understand the intrinsic mechanisms supporting contractility changes induced by a rapid temperature decrease in the ventricle of Rana ridibunda, and to investigate how fast they develop. Ventricular mechanical cycles (VMCs) and monophasic action potentials (MAPs) recorded from 15 isolated hearts were measured at 15, 30, 45, 60, 90, 120 and 150 s after the application of Ringer solutions of 20, 10 and 5 degrees C. Treatment with 10 and 5 degrees C Ringer solutions decreased the heart rate, and increased the magnitude of the ventricular contraction and the duration of the contraction and relaxation periods. The electrical changes included prolongation of the MAP depolarization plateau, which also decreased in amplitude as an effect of perfusion with 5 degrees C Ringer solution. In addition, treatment with 5 degrees C Ringer solution increased the latency of contraction. The block of L-type channels totally abolished the depolarization plateau at all perfusion temperatures, but failed to inhibit ventricular contraction. In conclusion, treatment with cold temperatures changes the electrical activity of the ventricular myocardium in R. ridibunda hearts, which results in modified ventricular contractility. Data suggest that in addition to L-type Ca2+ channels, other components that support calcium elevation are present R. ridibunda ventricular cells.     

Cytologic features of solitary fibrous tumor of the parotid gland. A case report

BACKGROUND: Solitary fibrous tumor (SFT) is a rare neoplasm that most commonly involves the pleura but is increasingly recognized at other locations, including lung, liver, thyroid and parotid glands, with only a few reports describing its cytologic features. CASE: The fine needle aspiration biopsy (FNAB) features of an SFT located in the left parotid gland of a 34-year-old woman were compared to the histologic and immunohistochemical aspects of the lesion. CONCLUSION: This case confirms that SFT has distinct cytomorphologic features and that FNAB can be helpful in its diagnosis.     

Conformational features of the four successive non-Watson-Crick base pairs in RNA duplex.

A tridecaribonucleotide, r(UGAGCUUCGGCUC) doesn't form hairpin or interior loop and forms a double helix of 12 base pairs including the four successive nonstandard base pairs, U.G-U.C-C.U-G.U, in the crystal. Non-Watson-Crick base pairs, G.U and U.C are nicely incorporated in RNA duplex maintaining the regular A-form backbone. There exist the good overlapping between base pairings, U.G and U.C, so as to stabilize the nonstandard base pair track. Hydrogen bond networks involving water molecules in the major and minor grooves to stabilize this mismatch base pairing array, are observed and its conformational features are described.     

Infants with single ventricle: a population-based epidemiological study

BACKGROUND: Single ventricle, a rare congenital cardiac defect, often occurs as part of a complex group of cardiovascular abnormalities. Little is known of its epidemiologic associations. METHODS: Using data from the Baltimore-Washington Infant Study [BWIS], (1981-89), a population based case-control study of cardiovascular malformations, infants with single ventricle were evaluated with respect to infant and family characteristics and maternal and paternal exposures. The cases were analyzed according to presence/absence of abnormal cardio-visceral situs. Controls were 3,572 infants without heart defects randomly selected from the regional cohort of live births. Odds ratios and 95% confidence intervals were used as measures of association. RESULTS: Single ventricle occurred in 1.25% of infants with congenital cardiovascular defects in the BWIS. Fifty-five infants had single ventricle. In 48 families (87.3%) the parents were interviewed. Thirty-three infants had normal situs and 15 had abnormal situs. Paternal alcohol consumption (OR = 2.0, 95% CI 1.1-3.9) and paternal cigarette smoking (OR = 2.4, 95% CI 1.1-5.1) were associated with all cases of single ventricle. These associations were even stronger in the subset of infants with abnormal situs. Maternal history of a previous induced abortion was also associated with infants born with abnormal situs (OR = 3.2, 95% CI 1.1-11.5). Paternal marijuana use was associated with cases of single ventricle in normal situs (OR = 2.2, 95% CI 1.0-5.2). CONCLUSIONS: Potential risk factors included paternal smoking and alcohol consumption, highlighting the need for future studies to consider environmental factors in the pathogenesis of this cardiac defect.     

Clinical observations and echocardiographic features of mural thrombi in the left ventricle during myocardial infarction]

The incidence and changes in the mural thrombi in left ventricle in ECHO-2D in the acute myocardial infarction as well as relationship between clinical parameters and echocardiographic indices of the left cardiac ventricle contractability asynergy and dynamics of changes in mural thrombi have been investigated. The studies included 137 consecutive patients (98 males and 39 females) treated for the acute myocardial infarction. Patients' age ranged from 35 to 87 years (mean 62 years). Infarction of the anterior and/or lateral wall was diagnosed in 67 patients, and infarction of the inferior and/or posterior wall in 70 patients. Mural thrombi were diagnosed in 42 (31%) patients. Eighteen thrombi (43%) were liquefied during hospitalization. Comparative analysis of patients in whom mural thrombi underwent liquefaction in the hospital and a group of patients with myocardial infarction and persisting mural thrombi showed that return of left ventricle movements with subsequent contractability facilitate liquefaction of mural thrombi. Higher mortality rate in the group of patients with myocardial infarction with mural thrombi is due to extension of the infarction accompanied by marked asynergy of left ventricular contractions which does not decrease in sequential examinations, and increasing congestive heart failure.     

Acute transient non-physiological over-sensing in the ventricle with a DF4 lead

The DF-4 is a new defibrillator lead technology. We present two cases of non-physiological transient ventricular over-sensing in patients who underwent implantation of an ICD for secondary prevention. Case 1 had ventricular over-sensing during pacing threshold evaluation post defibrillation testing while Case 2 had the lead integrity alert triggered immediately post discharge with transient over-sensing. No lead-connector issues were found. Case 1 was likely due to improper venting of the header and trapped air. Case 2 was hypothesized to be due to intermittent header pin non-contact secondary to blood in the header. These cases reveal that DF-4 leads are subject to both reported and potentially novel causes of transient acute ventricular over-sensing.     

The protein that binds to DNA base J in trypanosomatids has features of a thymidine hydroxylase

Trypanosomatids contain an unusual DNA base J (beta-d-glucosylhydroxymethyluracil), which replaces a fraction of thymine in telomeric and other DNA repeats. To determine the function of base J, we have searched for enzymes that catalyze J biosynthesis. We present evidence that a protein that binds to J in DNA, the J-binding protein 1 (JBP1), may also catalyze the first step in J biosynthesis, the conversion of thymine in DNA into hydroxymethyluracil. We show that JBP1 belongs to the family of Fe(2+) and 2-oxoglutarate-dependent dioxygenases and that replacement of conserved residues putatively involved in Fe(2+) and 2-oxoglutarate-binding inactivates the ability of JBP1 to contribute to J synthesis without affecting its ability to bind to J-DNA. We propose that JBP1 is a thymidine hydroxylase responsible for the local amplification of J inserted by JBP2, another putative thymidine hydroxylase.     

Neighboring base composition is strongly correlated with base substitution bias in a region of the chloroplast genome

Nucleotide sequence from a region of the chloroplast genome is presented for 12 species spanning four subfamilies of the grass family. The region contains the coding sequence for the rbcL gene and the intergenic spacer between the gene coding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase rbcL and the photosystem I gene psal. This intergenic spacer contains a pseudogene for rpl23 as well as two noncoding segments with different A+T contents. Using the sequence of rbcL a chloroplast phylogeny of this family was constructed by parsimony. Variable sites of the two noncoding segments were traced onto the phylogeny to study the dynamics of base substitution. This was also performed for the fourfold-degenerate sites of the rbcL gene. A wide variation in transversion/transition is observed between the two noncoding segments and between the noncoding DNA and the fourfold-degenerate sites of rbcL This variation is correlated with regional A+T content. As regional A+T content decreases, the ratio of transversions to transitions also decreases. Substitutions were then scored in relation to neighboring base composition. The composition of the two bases immediately flanking each substitution is highly correlated with the transversion/transition bias. When both the 5 and 3 flanking bases are an A or a T, transversions are observed 2.2 times as frequently as transitions. When either or both neighbors are a C or a G, the opposite trend is found; transitions are observed 1.5 times more frequently than transversions. Correspondence to: Brian R. Morton     

Morphometric evaluation of the myocardial interstitial space after physical and chemical fixation. A light-microscopic study on the left ventricle of canine hearts.

The interstitial space, separated into tissue clefts and interstitium within bundles of myocytes of left canine ventricle, was investigated qualitatively and morphometrically after using different methods of fixation following aortic cross clamping and 10 min of ischemia at 5 degrees C. In frozen sections, the size of tissue clefts is significantly lower than in semithin sections after immersion fixation. The interstitium within bundles of myocytes shows similar values independent of the fixation technique (r = 0.83). This constancy permits a free choice between the two fixation techniques, there being no loss of information from the material investigated.     

Electrostatic solitary structures in a magnetized nonextensive plasma with q-distributed electrons

A rigorous theoretical investigation has been made of obliquely propagating electrostatic solitary structures in a magnetized plasma, taking into account the effect of nonextensive electrons. By employing the reductive perturbation method, the basic characteristics of obliquely propagating ion-acoustic (IA) solitary waves (SWs) in a cold magnetized electron-ion plasma (consisting of inertial ions and noninertial q-distributed electrons) have been addressed. The Korteweg-de Vries equation is derived and its numerical solution is obtained. It has been shown that the effects of electron nonextensivity and external magnetic field significantly modify the natures of the small but finite-amplitude IA SWs. The present analysis may be useful to understand and demonstrate the dynamical properties of IA SWs in different astrophysical and cosmological scenarios (viz. stellar polytropes, hadronic matter, quark-gluon plasma, protoneutron stars, dark-matter halos, etc.).     

Massive false aneurysm of the left ventricle with dysphagia

A patient with a massive false aneurysm of the left ventricle following myocardial infarction is described. The pseudoaneurysm compressed the esophagus causing severe dysphagia, and contributed to advanced terminal cachexia.