Morphologic analysis of common atrioventricular valves in patients with right atrial isomerism

The objective of the study was to examine the relation between the morphology of the common atrioventricular valve and regurgitation of the valve in patients with right atrial isomerism. We examined seven consecutive patients with documented right atrial isomerism who subsequently underwent postmortem examination during a 10-year period. The degree of regurgitation and the diameters of the common valve were evaluated via cineangiography, and the site of regurgitation was evaluated by echocardiography. The morphology of the common atrioventricular valve was assessed further at autopsy. Cineangiography revealed valve diameters ranging from 14.8 to 27.8 mm (mean 20.9 mm). Valvar regurgitation was revealed within 2 months of birth in all patients. Regurgitation abruptly worsened in three patients after placement of a Blalock-Taussig shunt or a central shunt and postintubation. Autopsies revealed that the common atrioventricular valve consisted of four leaflets in five patients, and three leaflets in two. The anterior leaflets were large and protruding in all patients, and the lateral leaflets were thickened in six. All patients had a mass consisting of the left lateral leaflets and chordae with direct attachment of the chordae to the ventricular muscle (the right lateral leaflet was attached to the ventricular muscle and immobile in one patient). The lateral leaflets clung to the ventricular wall and exhibited poor movement in six patients. Leaflets with poor mobility corresponded to the regurgitant valvar site as assessed by echocardiography in six patients; and the regurgitation in three patients with acute deterioration occurred at the valvar side with poor mobility. It is concluded that the common atrioventricular valve in patients with right atrial isomerism has morphologic characteristics that may be associated with valvar regurgitation and malignant potential for abrupt deterioration after replacement of systemic-pulmonary shunting.

Interleukin-6 overexpression cannot generate serious disorders in severe combined immunodeficiency mice

C57BL/6 human interleukin-6 (IL-6) transgenic mice develop mesangial proliferative glomerulonephritis with massive IgG1 plasmacytosis and die of renal failure in early life. To test whether the IL-6 overexpression could cause development of mesangial proliferative glomerulonephritis without plasmacytosis or promote proliferation of immature B cells that have not undergone immunoglobulin gene rearrangement, the IL-6 transgene was introduced into mice with severe combined immunodeficiency (SCID). In the immunocompetent littermate IL-6 transgenic mice, there were various symptoms such as plasmacytosis, nephropathy, anemia, and thrombocytosis, accompanied by marked increases in serum IL-6 levels as they aged. All these mice died by 25 weeks of age. In contrast, the SCID-IL-6 transgenic mice had no such abnormalities, except certain hematological changes, although the transgene was expressed in various tissues. In these mice, the serum IL-6 levels were 10- to 15-fold higher than those in the nontransgenic mice, and they remained constant throughout their lives. Furthermore, there were no signs of lymphoid development. This study demonstrates that deregulation of IL-6 expression does not stimulate cell growth or differentiation of immature B cells, and thus does not result in plasmacytosis and age-related increases in IL-6 production, and also does not generate mesangial proliferative glomerulonephritis.

HLA-DRB4 genotyping by PCR-RFLP: diversity in the associations between HLA-DRB4 and DRB1 alleles

The serologically defined HLA-DR53 antigen is associated with HLA-DR4, -DR7, and -DR9 antigens, and these haplotypes contain two functional genes, DRB1 and DRB4, and two pseudogenes, DRB7 and DRB8. The DRB4 gene encodes the DR53 antigen, and has been officially recognized to contain three allelic variants (DRB4*0101, 0102, and 0103). In this study, we have established the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for DRB4 genotyping and analyzed genetic polymorphism of the DRB4 gene in Japanese population. DRB4*0101, DRB4*0102, and DRB4*0103 could be observed at the frequencies of 0.5%, 1.1% and 32.7%, respectively. The same DRB1 allele does not necessarily share an identical DRB4 allele. Further, a tight linkage disequilibrium was found between DRB4*0102 and DRB1*0401 in Japanese population, whereas DRB1*0401 was associated with DRB4*0101 or *0103 in Caucasian population. These findings reveal extensive diversity of the HLA-DRB1 and -DRB4 haplotypes and may have important implications for HLA-disease associations and donor selection in unrelated transplantation.

Repair of aortopulmonary window in an infant with extremely low birth weight

Although transaortic patch repair under cardiopulmonary bypass is a suitable procedure for aortopulmonary window, another method without cardiopulmonary bypass may be the only one for an infant with extremely low birth weight. We describe a successful repair of an infant with extremely low birth weight (758 g) by closing the window with a clip through a left thoracotomy. Cardiac catheterization 7 months after the operation showed no residual shunt and no stenosis of ascending aorta, pulmonary artery, or coronary arteries in the patient, whom we believe to be one of the smallest with successful repair.

Spectroscopic properties of fluorescence dye fura-2 with various divalent cations

We examined the effects of divalent cations on the fluorescence excitation spectra of fura-2 from a 2 ml solution containing 1 microM fura-2 with an excitation wavelength of 300-425 nm and an emission wavelength of 500 nm. The fluorescence spectra in solutions of fura-2-Ca2+, fura-2-Ba2+, and fura-2-Sr2+ complexes show almost the same pattern. The dissociation constants (Kd) of Ba2+ and Sr2+ with fura-2 were 1.63 and 9.02 microM, respectively, and these values were higher than that of the Ca2+ complex (222 nM). The effect of Mg2+ binding on the fluorescence of fura-2 was quite small, and Mn2+ quenched the fluorescence of fura-2. The spectra of the fura-2-Ca2+ complex were changed by the co-existence of another divalent cation. Divalent cations competitively bind to the binding site of fura-2 and show the respective fluorescence spectra; consequently, the composed fluorescence spectra according to the respective Kd.

Analysis of HLA-DM polymorphisms in sarcoidosis

Sarcoidosis is a multisystemic granulomatous disorder showing significant increases in the HLA-DRB1*11, *12, *14 and *08 alleles in the Japanese population. To evaluate the role of polymorphism in the DMA and DMB genes in predisposition to sarcoidosis, seventy Japanese patients with sarcoidosis and 95 unrelated healthy controls were analyzed in the third exon polymorphisms within the DMA and DMB genes by the PCR-RFLP method. There were no differences in the distribution of DMA alleles between the patient and control groups. The frequency of DMB*0102 was higher (p < 0.05) and that of DMB*0101 was lower (p < 0.05) in the patients than in the healthy controls. However, this association and negative association could be explained by linkage disequilibrium with the disease-associated DRB1 alleles. The DMA and DMB genes do not primarily confer the susceptibility to sarcoidosis.

Genetic polymorphisms in the keratin-like S gene within the human major histocompatibility complex and association analysis on the susceptibility to psoriasis vulgaris

Psoriasis vulgaris is associated with the HLA-Cw6 and Cw7 antigens. However, it has not yet been clarified if the HLA-Cw6 and Cw7 genes themselves are the susceptible gene related to this disease or if it is some other non-HLA gene in a linkage disequilibrium with these HLA-C alleles. The S gene, recently identified in the HLA class I region 160 kb telomeric of HLA-C, encodes a keratin-like protein and is expressed specifically in the granular layer of the epidermis. Therefore, it is tempting to speculate that the S gene is one of the strong candidate genes responsible for the pathogenesis of psoriasis vulgaris. Direct sequencing of the first and second exon of the S gene after polymerase chain reaction (PCR) amplification has allowed the identification of two diallelic polymorphic sites in exon I and seven diallelic polymorphic sites in exon 2, three among which result in amino acid exchanges, a Ser-Phe substitution at amino acid position 186, a Gly-Val substitution at position 393 and a Ser-Leu substitution at position 394. No significant difference in the dimorphic distributions of the S gene was observed between the patients with psoriasis vulgaris and healthy controls, suggesting that the susceptible gene for psoriasis is not the S gene itself.

cDNA cloning of the human homologues of the mouse Ke4 and Ke6 genes at the centromeric end of the human MHC region

cDNA clones corresponding to the HKE4 and HKE6 genes at the centromeric end of the HLA region on human chromosome 6p21.3 were isolated and characterized. The predicted amino acid sequences of HKE4 and HKE6 exhibited 81.5 and 85.6% identity to the mouse homologues, Ke4 and Ke6, respectively. HKE4 may encode a membrane protein with histidine-rich charge clusters. HKE6 possesses remarkable amino acid sequence conservation with several bacterial proteins with oxidoreductase function and also shows significant homology with the two unique functional domains containing the nucleotide cofactor binding site and the consensus motif characteristic of the members of the superfamily of short-chain alcohol dehydrogenases such as human and rat steroid and prostaglandin dehydrogenases.

Analysis on allelic variation of the HLA-DMB gene in Japanese by PCR-RFLP as well as direct DNA sequencing and identification of a new DMB allele, DMB*0105

In the HLA-D region, one of the class II genes, DMA and DMB have been identified between the DQ and DP genes, and four allelic polymorphisms in each of the DMA (DMA*0101 approximately 0104) and DMB (DMB*0101 approximately 0104) genes have been so far recognized. Several recent studies suggested that the DM molecule is required for class II antigen presentation pathway especially by promoting the binding of antigenic peptides to the classical HLA class II molecule. In this study, we have analyzed genetic polymorphism and allelic variation of the DMB gene in a Japanese population by the direct DNA sequencing technique and also by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and could recognize DMB*0101 (49.3%), DMB*0102 (23.2%), DMB*0103 (23.2%), and DMB*0104 (0.4%). Further, a new DMB allele, DMB*0105 characterized by the presence of Val and Ile at two polymorphic sites, codons 144 and 179, respectively was identified. Strong linkage disequilibria were found between DMB*0101 and DRB1*0101, DPB1*0402 and DRB1*1502, and also between DMB*0103 and DRB1*1501 and DQB1*0602. HLA-DMB genotyping using the PCR-RFLP method established here will provide accurate evaluation of the effects of sequence allelism in the DMB gene on the HLA class II disease associations.

The wavelength dependence of optically recorded action potentials in the atrial muscles of the bullfrog (Rana catesbeiana)

The action potentials from frog atrial muscles that had been stained with either merocyanine rhodanine or merocyanine oxazolone dyes were recorded optically. Then the dependence of the maximum rising phase of the optically recorded action potential on the wavelength of the incident beam was analyzed. The atrial muscle stained with two kinds of dyes showed no wavelength dependence in the duration of the rising phase (defined in Fig. 1) in the maximum rising phase of the action potential. These results were consistent with the structure of the membrane system of the frog heart. However, for the atrial muscles stained with merocyanine oxazolone dye, the optical signals recorded at 718 nm of the incident beam showed a second rising phase after the initial rapid rising phase of the optical signal, and this phase was not observed in the optical signals recorded at other wavelengths.

Distribution of inflammation and atrophy in the stomach of Helicobacter pylori-positive and -negative patients with chronic gastritis

OBJECTIVES

To investigate the extent of inflammation and atrophy in the stomach of Helicobacter pylori-positive and -negative patients with chronic gastritis.

METHODS

Endoscopy with biopsies from the lesser curvatures of the antrum, angulus, middle body, and the greater curvature of the middle body of the stomach was performed in 59 patients with histologically confirmed chronic gastritis. The extent of atrophic gastritis was assessed endoscopically as well histologically. H. pylori status was assessed by histology as well as enzyme-linked immunosorbent assay. The histological severity of chronic and acute inflammation, glandular atrophy, and intestinal metaplasia was assessed according to the Sydney system.

RESULTS

In H. pylori-positive patients, H. pylori was evenly distributed throughout the stomach when the extent of atrophic gastritis was limited to the antrum and the lesser curvature of the body, but disappeared from the antrum of patients with more extensive atrophic gastritis. The severity of acute and chronic inflammation at the greater curvature of the body increased with the extension of atrophic gastritis. In H. pylori-negative patients, the severity of chronic inflammation at the greater curvature of the body was significantly higher in patients with extensive atrophic gastritis than in those with a lesser extent of atrophic gastritis.

CONCLUSION

At the greater curvature of the body, the development of atrophy is closely associated with the increase in the severity of inflammation, which is more marked in H. pylori-positive patients.

Surgical atrial septostomy without cardiopulmonary bypass

Surgical atrial septostomy using a special atriotomy knife without cardiopulmonary bypass in patients with obstruction of the left-sided atrioventricular valve and complex cardiac anomalies is described. This procedure is effective, safe, and economical for patients in the acute stage after intracardiac repair, and available for patients with a closed fossa ovalis.

Bone marrow neutrophilia and suppressed bone turnover in human interleukin-6 transgenic mice. A cellular relationship among hematopoietic cells, osteoblasts, and osteoclasts mediated by stromal cells in bone marrow

To elucidate the effect of interleukin-6 (IL-6) on bone and bone marrow (BM), human IL-6 transgenic mice (hIL-6 tgm) were produced. Their bone and BM were examined histologically, radiologically, histomorphometrically, and hematologically on a temporal basis. hIL-6 tgm showed histologically evident neutrophilia in BM. Increase in precursors of granulocytes and monocytes in hIL-6 tgm was demonstrated by an assay for colony forming unit in culture (CFU-C) of BM cells. Decrease in osteoblasts and osteoid and suppression of primary spongiosa formation were predominantly observed in hIL-6 tgm at 14 weeks old, the terminal stage of life for hIL-6 tgm. An assay for colony forming unit in fibroblastic (CFU-F) of BM cells revealed a decrease in osteoblast precursor (with regard to alkaline phosphatase-positive colonies) in hIL-6 tgm at 15 weeks old. Histomorphometry demonstrated a decrease of both osteoclast number and bone resorption in hIL-6 tgm. These results suggested that enhanced granulocytic hematopoiesis, suppressed bone turnover, and alteration of cellular population in stromal cells in BM occurred in hIL-6 tgm. Thus we provide new findings that facilitate understanding of cellular interrelationships among hematopoietic cells, osteoblasts, and osteoclasts mediated by stromal cells in BM.

Optimal degree of pulmonary artery banding--adequate circumference ratio to calculated size from normal pulmonary valve dimensions

These findings suggest that PA banding may be suitable in children with congenital heart disease and excessive pulmonary flow, and that best results are obtained when the band circumference is < 90% of the standard pulmonary valve-ring circumference, as calculated from an equation derived from normal pulmonary valve dimensions. This guideline applies equally well to small infants weighing < 3 kg and to larger patients.

Anti-CD18 attenuates deleterious effects of cardiopulmonary bypass and hypothermic circulatory arrest in piglets

Cardiopulmonary bypass (CPB) and hypothermic circulatory arrest induce leukocyte and platelet activation and cytokine production as part of the inflammatory response to bypass. These events are thought to be responsible for producing at least some of the morbidity of bypass. We studied the effects of a monoclonal antibody to a specific leukocyte adhesion integrin, CD18, on the deleterious effects of CPB and circulatory arrest in piglets using techniques from infant heart surgery. Seventeen immature piglets were subjected to CPB, cooling, 1 hour of circulatory arrest at 15 degrees C, and subsequent reperfusion and rewarming. Nine piglets received anti-CD18 monoclonal antibody (group MAb), and eight randomly selected control piglets received none (group C). Monoclonal antibody to leukocyte integrin CD18 significantly decreased deleterious effects of CPB and hypothermic circulatory arrest in our immature animal model. This study suggests that antiadhesion therapy that alters fundamental leukocyte/endothelial interactions during open heart surgery may be protective against some deleterious effects of bypass and circulatory arrest in infants.

A program for calculating the total concentrations of ligands and metals at any temperature, ionic strength and pH for solutions with a controlled metal concentration

A program for calculating the total concentrations of ligands and metals at any temperature, ionic strength and pH for solutions with a controlled metal concentration was written in Quick-Basic. For the calculation, the absolute stability constants of ligands and the proton activity coefficient were corrected for temperature and ionic strength.

Monitoring of hepatic venous oxygen saturation for predicting acute liver dysfunction after Fontan operations

Acute liver dysfunction after Fontan operations may result from inadequate hepatic perfusion along with low cardiac output and high central venous pressure. We monitored hepatic venous oxygen saturation in 15 patients after Fontan operations to determine whether oxygen saturation predicts the occurrence and severity of acute liver dysfunction. We measured oxygen saturation from hepatic venous blood samples every 4 to 5 hours for at least 24 hours after the operation and used the mean hepatic venous oxygen saturation value for the first 24 hours after the operation to analyze the relationship between oxygen saturation and hepatic function. As indices of hepatic function, we measured serum alanine aminotransferase, total bilirubin, blood lactate (arterial, hepatic venous, and the difference between them), and the arterial ketone body ratio (the ratio of aceto-acetate to beta-hydroxybutyrate). For alanine aminotransferase and bilirubin, we used the maximal values during the first week in the analysis, and for blood lactate and ketone body ratio, we used the mean values for the first 24 hours after the operation. Significant broken-line regression relationship existed between mean hepatic venous oxygen saturation and hepatic function indices (alanine aminotransferase, total bilirubin, and blood lactate). The interpretation of these relationships is that hepatic indices are constant above the critical mean hepatic venous oxygen saturation values but are correlated with mean hepatic venous oxygen saturation below critical points in the range of 21% to 26%. Thus a hepatic venous oxygen saturation value below about 25% during the first 24 hours after a Fontan operation predicts the occurrence and the severity of acute liver dysfunction. We suggest that monitoring hepatic venous oxygen saturation is useful for management of critically ill patients after Fontan operations.

[Reoperation for obstructed extracardiac conduit after Rastelli operation--an autogenous tissue reconstruction (Danielson) method]

Eight patients with a mean age of 13.0 years underwent reoperation for obstructed extracardiac dacron conduit with xenograft valve at a mean of 7 years after Rastelli operation. In two patients, infective endocarditis of the stenotic conduit was the main indication for the reoperation. Diagnoses included 3 tetralogy of Fallot with pulmonary atresia, 3 d-TGA (III), 1 truncus arteriosus, and 1 corrected TGA. The conduit was completely excised leaving the posterior half of the autogenous external peel of conduit as the new outflow bed and a monocusped patch was then placed. Operations were mostly carried out allowing the heart to continue to beat. One patient with c-TGA who underwent concomitant replacement of aortic and left A-V values died in the hospital 4 months postoperatively. In other 7 patients, systolic pressure gradient across the right ventricular outflow decreased from a mean of 80.3 mmHg to 16.0 mmHg. Postoperative pulmonary regurgitation by UCG were trivial in 3 and grade III in 3 patients. One patient required re-reoperation late postoperatively for re-stenosis due to contracture of Golaski outflow patch. Three patients did not require any homologous blood during either the operation or the rest of the hospital stay. The results suggests that this method is a simple and effective option for reoperation of obstructed extracardiac dacron conduits late after Rastelli operation.