A unique CD45 glycoform recognized by the serum mannan-binding protein in immature thymocytes

The serum-mannan binding protein (S-MBP) is a calcium-dependent C-type lectin specific for mannose and N-acetylglucosamine. S-MBP is known as a host defense factor involved in innate immunity, where the target ligands for S-MBP should be on the surface of exogenous microorganisms. In this study, we tried to find endogenous ligands for this endogenous lectin. Among the cells tested, only the lymphocytes from thymus of BALB/c mice expressed ligands for S-MBP on their surface, those from bone marrow, spleen, mesenteric lymph nodes and peripheral blood all being negative. Interestingly, among the thymocytes, only the immature thymocytes with the CD4+CD8+CD3low phenotype expressed ligands for S-MBP, and ligands for S-MBP decreased on their maturation. A major cell surface glycoprotein bearing S-MBP ligands was isolated and identified as CD45RO, which is a transmembrane protein with tyrosine phosphatase activity. Deglycosylation experiments with N-glycanase and endoglycosidase H indicated that the S-MBP ligands on thymic CD45 are high mannose type or hybrid type N-linked oligosaccharides. This unique presentation of S-MBP ligands on this special CD45 isoform suggested the possibility that the oligosaccharide portion of CD45 on immature thymocytes is associated with the maturation, development or selection events of thymocytes.

Pituitary choristoma composed of corticotrophs and adrenocortical cells in the sella turcica

A pituitary tumour composed of well-differentiated corticotrophs and adrenocortical cells is reported. Sections of the tumour revealed a mixture of small round cells with amphophilic or basophilic periodic acid-Schiff (PAS)-positive cytoplasm and large spherical and oval cells with abundant, granular, partly vacuolated PAS-negative cytoplasm. The small cells contained type 1 cytokeratin-positive microfilaments, numerous 250-500 nm endocrine-type secretory granules immunoreactive for adenocorticotropic hormone (ACTH) and beta-lipotropin. The large cells possessed ample cytoplasm filled with abundant vesicular smooth endoplasmic reticulum, numerous mitochondria possessing tubulovesicular cristae and frequent dense bodies. They lacked the features of pituitary endocrine cells or folliculostellate cells and were found to contain a panel of steroidogenic dehydrogenases and hydroxylases. The tumour was classified as a choristoma, in which two distinct cells types, corticotrophs and adrenocortical cells, were mixed. We suggest that, under continued ACTH stimulation, umcommitted stem cells may differentiate into adrenocortical cells. Alternatively, the presence of adrenocortical cells may be the result of heterotopia.

Sonicated albumin for evaluating midventricular obstruction in hypertrophic cardiomyopathy

The flow dynamics of midventricular obstruction in hypertrophic cardiomyopathy were evaluated with intravenous injection of sonicated albumin in 14 patients with vague velocity profiles on conventional continuous wave Doppler echocardiography. Nine patients (64%) demonstrated a clear envelope after the injection. The following three patterns of continuous Doppler profiles were obtained : 1) a monophasic flow profile with a brief and sharp increase in peak velocity in late systole, 2) a late-peaking systolic flow and a diastolic flow during isovolumic relaxation time emerging after sonicated albumin injection (biphasic flow profile), 3) a biphasic flow profile with systolic and diastolic flow waves having a notch around the second heart sound. The calculated peak pressure gradients from the modified Bernoulli equation did not differ significantly with the presence of diastolic wave or the site of obstruction. Therefore, these are independent parameters for estimating the severity of midventricular obstruction. Therefore, these are independent parameters for estimating the severity of midventricular obstruction. The sonicated albumin method was useful in delineating the flow profile, and thus evaluating the hemodynamics of midventricular obstruction in hypertrophic cardiomyopathy.

Significance of detection of enterovirus RNA in myocardial tissues by reverse transcription-polymerase chain reaction

Enteroviruses are known to have association with human myocarditis and dilated cardiomyopathy (DCM). We screened biopsy specimens from patients with active myocarditis or DCM, and myocardial tissues from autopsy cases without cardiac diseases using polymerase chain reaction (PCR) gene amplification. Positive enteroviral signals were demonstrated from 4 of 5 patients with active myocarditis (80%), 7 of 42 patients with DCM(17%) and 3 of 27 autopsies (11%). Out of 7 PCR positive patients with DCM, 3 cases showed hypertrophy and disarray of cardiocytes, fibrosis in the interstitium, and a few inflammatory infiltrates. The remaining 4 cases with DCM and 3 PCR positive autopsy cases did riot exhibit histological findings compatible with those in myocarditis. Our results support the observations that enteroviruses are common aetiologic agents of myocarditis, and some cases of DCM. Our results also suggest the possibility that in some cases enteroviruses may persist in the myocardium without causing apparent pathological changes.

Familial aggregation of dilated cardiomyopathy--evaluation of clinical characteristics and prognosis

To investigate the prevalence, clinical characteristics, and prognosis of familial cases of idiopathic dilated cardiomyopathy (IDC), family screenings were carried out in 117 IDC patients and their relatives. Familial occurrence was suspected in 29 families (25%). Ten families (9%) with 24 patients were confirmed to be familial, but the other 19 families (16%) remained suspected. The age at the time of diagnosis was lower and the cardiac symptoms tended to be milder in the familial group than in the non-familial group, but there were no differences in other clinical parameters. There was also no difference in the survival rate. However, when only NYHA class III and IV patients were selected, the 1-year and 5-year survival rates were lower in the familial group than in the non-familial group. Congestive heart failure was the most common cause of death in the non-familial group, while sudden death was the most common cause of death in the familial group. Among familial IDC patients who were deceased, the left ventricular end-diastolic pressure was higher and the cardiac index was lower at the time of diagnosis than those in patients who were still alive. We conclude that, since the prognosis of familial IDC patients is poor once their cardiac symptoms become severe, early diagnosis and treatment are extremely important.

Cardiac involvement in a family with Becker muscular dystrophy

We report a family with Becker muscular dystrophy (BMD) presenting with cardiac involvement. The proband was a 41-year-old Japanese man who was hospitalized with exertional dyspnea and muscle weakness. Cardiac examination showed findings consistent with dilated cardiomyopathy. Dystrophin immunohistochemical analysis showed a discontinuous patchy staining pattern in cardiac and skeletal muscles biopsied from the proband. His brothers had high creatine kinase (CK) activity and abnormal electrocardiogram. Dystrophin gene analysis revealed that the proband and his brothers had G-to-T transversion at the terminal nucleotide of exon13. We conclude that the mutated dystrophin gene may cause cardiac involvement as a symptom precedent to skeletal muscle involvement.

Suppression of HIV replication in human monocyte-derived macrophages induced by granulocyte/macrophage colony-stimulating factor

Susceptibility to HIV infection was examined in macrophages differentiated from human monocytes by macrophage colony-stimulating factor (M-CSF) or granulocyte/macrophage colony-stimulating factor (GM-CSF). The replication of macrophage-tropic human immunodeficiency virus type-1 (HIV-1), which was determined by reverse transcriptase (RT) activity, was significantly suppressed in macrophages induced by GM-CSF (GM-type macrophages) but not in those induced by M-CSF (M-type macrophages). Multinucleated giant cells were formed only in M-type macrophages after HIV infection. However, the expression of CD4 molecules on the surface of both types of macrophages was similar and the proviral DNA was detectable in cell lysates of both macrophages, although the amount of proviral DNA in M-type macrophages was higher than that in GM-type macrophages. Many steps have been defined in HIV infection and replication, such as adsorption of HIV to the cell surface, internalization of the viral core into the cytoplasm, uncoating of viral RNA, reverse transcription and integration of proviral DNA into cellular DNA, transcription and translation of proviral DNA, assembly of viral components, and budding of virus particles. Our findings suggested that the suppression of HIV-1 replication in macrophages induced by GM-CSF is mainly due to a disturbance at certain steps of replication after synthesis of the proviral DNA. Thus, the suppression of HIV replication in GM-type macrophages may provide a model of the latency of HIV infection in vivo.

Disappearance of neutrophil fluctuations in a child with cyclic neutropenia by combination therapy of granulocyte colony-stimulating factor and high-dose immunoglobulin

We report on a patient with cyclic neutropenia who was treated by granulocyte colony-stimulating factor (G-CSF) and high-dose immunoglobulin. The serial examination revealed cyclic fluctuations in the numbers of neutrophils, monocytes, platelets in peripheral blood, and in the serum G-CSF concentration. Bone marrow examination confirmed a cyclic fluctuation of both progenitor cells (CFU-GM) and CD10-positive B cells. The therapy of G-CSF followed by high-dose immunoglobulin achieved a disappearance of neutrophil oscillations. It suggested that the combination therapy of G-CSF with high-dose immunoglobulin might be effective for cyclic neutropenia.

[The influence of electrical time interval indices and aging on the left atrial systolic time intervals]

The influence of aging and heart rate on left ventricular systolic time intervals is well known, but the effects on left atrial systolic time intervals, a new index of left atrial function, remain unknown. The influence of aging and heart rate on left atrial systolic time intervals was investigated in 43 normal subjects (13-72 years of age) by Doppler echocardiography. Atrial pre-ejection period, atrial ejection time, and corrected atrial pre-ejection period were obtained by transmitral Doppler echocardiography. Simple regression analysis showed atrial pre-ejection period significantly correlated with P wave duration (PP; r = 0.78), and PR interval (PR; r = 0.60), but not with RR interval (RR). However, multiple regression analysis showed atrial pre-ejection period significantly correlated only with PP. Simple regression analysis found atrial ejection time significantly correlated with PP (r = 0.38), and PR (r = 0.39), but not with RR. However, multiple regression analysis found atrial ejection time did not correlate with any factor significantly. Aging was significantly correlated with corrected atrial pre-ejection period (r = -0.37), but not with corrected atrial ejection time and atrial pre-ejection period. Atrial ejection time significantly correlated with corrected atrial pre-ejection period (r = -0.37), but not with atrial pre-ejection period. Corrected atrial pre-ejection period is a clinically useful index of left atrial systolic function.

Interaction of beta-lactam antibiotics with the penicillin-binding proteins of penicillin-resistant Streptococcus pneumoniae

The binding of five structurally diverse beta-lactam antibiotics to penicillin-binding proteins (PBPs) of two clinical isolates of Streptococcus pneumoniae resistant to penicillin G was compared with that of a susceptible strain. A common feature of the PBP patterns of the resistant strains was the absence of PBP 1a detected in the susceptible strain. For each beta-lactam antibiotic tested, there appeared to be significant decreases in the affinity for BPB 1b, 2a and 2b of the resistant strains. We attempted to evaluate a quantitative correlation between the antibacterial activity of the drugs for three strains and their affinity for the various PBPs. A close correlation was found between the minimum inhibitory concentrations and the affinity for PBP 2a, but not for any of the other PBPs.

[Comparison of the long-term results of intra or extracardiac implanted bioprosthetic valves]

The long-term results following intra or extracardiac implanted bioprosthetic valves were compared. Forty-one patients, whose average age at the operation was 43.3 +/- 10.7 (mean +/- SD) year-old, were implanted 33 Hancock and 11 Carpentier-Edwards porcine valves, 35 in mitral, 6 in aortic and 3 in tricuspid position. Twenty-five children, whose average age was 6.0 +/- 3.5 year-old (p < 0.01) at the operation, underwent right ventricular-pulmonary artery conduit repair with 16 Hancock, 7 Carpentier-Edwards porcine valves and 2 Ionescu-Shiley pericardial valves. There were only one late death and one operative death in the patients implanted intracardiac bioprosthetic valves. Seven intracardiac and 12 extracardiac implanted bioprosthetic valves were removed at the reoperation for prosthetic valve dysfunction. The probabilities free from reoperation after 7 and 9 years of follow-up was 91% and 82%, respectively, with intracardiac implanted valves, on the other hand 51% (p < 0.05) and 8.6% (p < 0.05), respectively, with extracardiac implanted valves. Valve dysfunction in extracardiac implantation was mainly related to the stenosis due to fusion of comissure and/or calcification. Regurgitation due to tear and/or perforation was mainly associated with intracardiac implanted bioprosthetic valves.

Effects of Helicobacter pylori infection on healing and recurrence of gastric ulcers

OBJECTIVES

The effects of Helicobacter pylori infection on the healing and recurrence of gastric ulcers were investigated.

METHODS

Eighty-five and 17 patients with endoscopically-proven gastric ulcer with and without H. pylori infection, respectively, received 800 mg of cimetidine daily. Healing of ulcer and H. pylori infection were assessed at wk 12. After the 12-wk-treatment period, 67 and 16 patients with healed ulcer positive and negative for H. pylori infection, respectively, received maintenance treatment (cimetidine 400 mg daily). Ulcer recurrence and H. pylori infection were assessed at or within 24 wk from the beginning of maintenance treatment. Variables influencing ulcer healing and recurrence were analyzed by multiple regression analysis.

RESULTS

Ulcer healing at wk 12 was similar in patients with and without H. pylori infection, occurring in 16 (89%) of 18 patients without H. pylori infection, compared with 67 (87%) of 77 patients with H. pylori infection. At or within 24 wk from the start of maintenance therapy, ulcer recurrence was significantly more frequent in patients with H. pylori infection than in those without: it occurred in three (20%) of 15 patients without H. pylori infection, but in 37 (58%) of 64 patients with infection. Multiple regression analysis showed that H. pylori infection was related most closely to ulcer recurrence independently.

CONCLUSION

H. pylori infection had a significant independent influence on gastric ulcer recurrence, but not initial ulcer healing.

Characterization of a wild poliovirus type 3 isolated Japan in 1993

A wild poliovirus type 3 was isolated from a throat swab of a patient with upper respiratory symptoms without paralysis in Shiga Prefecture, in 1993. Wild poliovirus has never been isolated in these nine years in Japan. The most recent isolation of wild poliovirus was of type 1 in 1984 from a case of encephalomyelitis in Aichi Prefecture. Antigenic and PCR-restriction fragment length polymorphism analyses revealed that the Shiga strain was non-Sabin origin. Sequence analysis of the VP1 region confirmed that the isolate was a wild poliovirus type 3. Furthermore, this isolate had higher homology to the isolates from North Vietnam than those from Pakistan or Finland, suggesting that the Shiga strain was imported from Asian area. This strain was also shown to be neurovilurent in transgenic mice carrying human poliovirus receptor gene.

Oligomeric structures required for complement activation of serum mannan-binding proteins

Serum mannan-binding protein (S-MBP) comprises a series of homooligomers, and activates complement when it binds to appropriate carbohydrate ligands. In this study, the structural requirements necessary for complement activation were examined for rat, rabbit, and human S-MBPs. On SDS-PAGE under non-reducing conditions, the S-MBPs gave three major bands: large, middle, and small oligomers. Since three subunits (23-25 kDa) form a triple helix (the base structural unit) at the collagen-like domain within the S-MBP molecule, it was estimated that human and rabbit S-MBPs comprise a mixture of pentamers, tetramers, and trimers of the respective structural units. In contrast, rat S-MBP is composed of tetramers, trimers, and dimers. The large and middle oligomers were almost equal in their ability to activate complement, whereas the small oligomers had very low or no activity. Upon digestion with bacterial collagenase, the large and small oligomers were degraded almost completely. In contrast, the middle oligomers remained largely intact, and the surviving middle oligomers retained complete ability to activate complement. The degraded product, trimers of the carbohydrate recognition domain (CRD), did not show any complement activating activity. These data indicate that not only the structural integrity of the S-MBP collagen-like domain and CRD, but also a unique conformational structure present in the middle oligomers are critically important for carbohydrate-mediated complement activation.

Developmental expression of D-galactoside-binding lectin in sea urchin (Anthocidaris crassispina) eggs

The spatial and temporal expression of a sea urchin (Anthocidaris crassispina) egg lectin (SUEL) during early embryogenesis was studied using antiserum raised against SUEL. Western blotting analysis revealed the presence of SUEL in all stages so far examined, from unfertilized eggs to gastrula stage embryos. Immunofluorescence and immunoelectron microscopic observation showed that SUEL was stored in small electron-dense granules which migrated to the cortex within 10 min after fertilization. SUEL was localized in the cortical cytoplasm of the blastomere during cleavage stages and subsequently migrated to the outer surface of the embryo, including the invaginated portion of the gastrula. Immunoelectron microscopic study indicated that SUEL was deposited in the hyaline layer at least at the mid gastrula stage. Migration of SUEL to the cortex was significantly reduced by treatment with cytochalasin B, suggesting that actin filaments play an important role in this translocation. Exogenously added SUEL was adsorbed at the surface of unfertilized eggs and hatched embryos, but not to embryos with fertilization membrane. Lactose inhibited this adsorption, suggesting the presence of an endogenous glycoligand(s) specific for SUEL on the surface of unfertilized eggs and in the hyaline layer. We conclude that SUEL is secreted at a certain stage of embryogenesis and specifically adsorbed to the hyaline layer. Temporal changes in extraembryonic matrices caused by SUEL seem to play an important role in developmental morphogenesis.

[Pulsed Doppler findings of the pulmonary vein flow in mitral stenosis]

Left atrial function was assessed by transesophageal echocardiography in 8 patients with mitral stenosis and sinus rhythm (MS group), and 16 age-matched normal controls (C group). Pulsed Doppler findings of left upper pulmonary vein flow were classified into first and second forward waves during systole (S1, S2), forward wave during diastole (D), and backward flow during left atrial contraction (PVA). Peak velocity (P) and time-velocity integral (TVI) of each wave and acceleration and deceleration slope of S2 wave (S2-Ac, S2-Dc) were obtained. TVI-S2 and P-D in the MS group were significantly lower than those in the C group (TVI-S2: 4 +/- 2 vs 12 +/- 3 cm, P-D: 27 +/- 13 vs 41 +/- 12 cm/sec). S2-Ac and S2-Dc in the MS group were significantly higher than those in the C group (S2-Ac: 456 +/- 116 vs 323 +/- 118 cm/sec2, S2-Dc: 380 +/- 102 vs 165 +/- 48- cm/sec2). There were no differences in S1 and PVA. Lower TVI-S2 in the MS group suggests decreased reservoir function of the left atrium. Lower TVI-S2 in the MS group was caused by increased S2-Ac and S2-Dc which suggests increased left atrial preload and deterioration of left atrial compliance. Decreased P-D in the MS group reflects dysfunction of mitral valve opening.

Noninvasive evaluation of contractile state by left ventricular dP/dtmax divided by end-diastolic volume using continuous-wave Doppler and M-mode echocardiography

The maximum rate of left ventricular (LV) pressure rise (dP/dtmax) is commonly used in the assessment of directional change in LV contractility and, recently, estimated by analyzing continuous-wave Doppler ultrasound velocity curve of mitral regurgitation. As an alteration in ventricular preload is known to affect dP/dtmax, normalized dP/dtmax for preload might be more reliable to assess LV contractile state. To investigate the usefulness of a new index of LV contractile state determined by continuous-wave Doppler analysis of mitral regurgitation and M-mode echocardiogram-derived LV end-diastolic volume, we studied 18 patients with mild mitral regurgitation. The continuous-wave Doppler velocity curves of mitral regurgitation were digitized and converted to instantaneous pressure gradient between the LV and left atrium using the simplified Bernoulli equation. The maximum value of its first derivative (Doppler-derived dP/dtmax) correlated well with LV dP/dtmax using simultaneously recorded LV pressures by manometer-tipped catheter (n = 20, r = 0.97, p < 0.001). Corrected Doppler-derived dP/dtmax for LV end-diastolic volume using Teichholz's method significantly increased by inotropic stimulation with dobutamine (p < 0.01); however, it remained unchanged by augmentation of afterload with angiotensin II. Thus, the LV dP/dtmax can be accurately estimated in humans by analyzing the continuous-wave Doppler velocity curve of mitral regurgitation, and corrected Doppler-derived dP/dtmax for LV end-diastolic volume is relatively independent of loading alteration and sensitive to inotropic stimulation. We concluded that echocardiographic assessment by combined Doppler- and M-mode measurements provides a useful and sensitive index of LV contractile state noninvasively.

Left atrial backward ejection in symptomatic hypertrophic cardiomyopathy--assessment by transthoracic and transesophageal Doppler echocardiography

BACKGROUND

During atrial contraction, the left atrium produces both forward ejection to the left ventricle and backward ejection to pulmonary veins.

PURPOSE

To determine quantitatively left atrial ejection performance in symptomatic hypertrophic cardiomyopathy (HCM) patients by using left atrial systolic time intervals.

METHOD

Thirty-one patients with symptomatic HCM and sinus rhythm and 31 normal subjects were studied with transthoracic and transesophageal Doppler echocardiography. Left atrial pre-ejection period (APEP), corrected atrial pre-ejection period (APEPc), and the duration (AET) and the time velocity integral (IA) of the atrial contraction wave in transmitral flow were determined. The duration (PV-AET) and the time velocity integral (PV-IA) of reverse pulmonary venous flow during atrial contraction were also determined.

RESULTS

For normal subjects, significant correlations were found between APEP and electrocardiographic P wave duration (r = 0.78, p < 0.001), and between APEPc and left atrial forward ejection indices (AET: r = -0.42, p = 0.01, IA: r = -0.54, p < 0.05, respectively), but not between APEP and either of the two latter indices. These findings indicate that, for normal subjects, APEPc is a better index of left atrial systolic function than APEP. In contrast, for HCM patients, significant correlations were found between APEPc and left atrial backward ejection indices (PV-AET: r = -0.49; p < 0.005, PV-IA: r = -0.66; p < 0.001, respectively), but not between APEPc and left atrial forward ejection indices.

CONCLUSION

Augmentation of left atrial afterload may result in decreased left atrial forward ejection and increased left atrial backward ejection. Thus, both left atrial forward ejection and left atrial backward ejection must be considered in the assessment of left atrial ejection performance in patients with symptomatic HCM.

A novel isoform of the neurofibromatosis type-1 mRNA and a switch of isoforms during murine cell differentiation and proliferation

Four types of cDNAs encoding the GTPase-activating protein-related domain (GRD) of the mouse neurofibromatosis type-1 gene (NF1) have been cloned. One of these isoforms was a newly identified form termed type IV. Analysis of the genomic structure of the mouse NF1-GRD revealed two exons (23A and 23B) between exons 23 and 24, leading to the production of four types of NF1-GRD cDNAs by an alternative splicing mechanism. Amino-acid sequences encoded by NF1-GRD are highly conserved between human and mouse. Analysis of the expression of these transcripts in various tissues of adult mouse revealed that the type-I transcript is predominantly expressed in neural tissues such as brain and spinal cord. Other forms, termed types II, III and IV, are also expressed in various tissues. The type-I and type-II transcripts are expressed equivalently in undifferentiated P19 mouse teratocarcinoma cells, whereas type-I expression becomes predominant during neuronal differentiation by retinoic acid treatment. Expression of type I is also shown to be correlated with cessation of cell proliferation in P19 cells, but not in NIH3T3 cells. These, together with other results, suggest that the four types of NF1-GRD transcripts generated by alternative splicing have some important biological roles in cell differentiation and proliferation.

Monozygotic twins of different apparent sex

We report on twins of unlike sex who shared a 45,X/46,X,+mar karyotype. The mar chromosome was found to be Yq- by DNA analysis. Marker studies, including 8 VNTR loci, yielded a probability of monozygosity of 0.99999996.

Endothelium-derived relaxing factor released by 5-HT: distinct from nitric oxide in basilar arteries of normotensive and hypertensive rats

1. The role of the endothelium in cerebrovascular responses to 5-hydroxytryptamine (5-HT) was investigated in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) in vitro. 2. Cumulative addition of 5-HT caused concentration-dependent contractions in ring preparations of SHR basilar arteries; the contractile response was smaller in WKY basilar arteries. 3. Removal of the endothelium enhanced markedly the contractile responses to 5-HT in WKY arteries but had only a slight effect in SHR arteries. The responsiveness to 5-HT in WKY arteries after removal of endothelium was comparable to that in SHR arteries. 4. The endothelium-dependent relaxation induced by acetylcholine in WKY basilar arteries was almost abolished by treatment with 10 microM methylene blue or 10 microM NG-nitro-L-arginine (L-NOARG). However, the response to 5-HT was not affected by treatment with methylene blue, L-NOARG or indomethacin. 5. Application of 10-20 mM K+ or 3.2 mM tetraethylammonium (TEA) did not change significantly, or only increased slightly, the resting tension, but markedly enhanced the contractile response to 5-HT in WKY arteries with endothelium. In contrast, the submaximal response to 5-HT in SHR arteries with endothelium was significantly enhanced by 0.3 mM TEA. 6. In the presence of 1 mM TEA, the application of 10 microM L-NOARG further enhanced the responses of 5-HT in WKY arteries with endothelium. In SHR arteries with endothelium, 10 microM L-NOARG per se enhanced slightly but significantly the responses to 5-HT. 7. These results indicate that 5-HT-induced contraction in basilar arteries is substantially attenuated by an endothelium-dependent mechanism in WKY, but to a much lesser extent in SHR. The major relaxing factor released by 5-HT from endothelium in WKY is distinct from NO and may exert its effect by activating K+ channels.

New modification of the Damus-Kaye-Stansel operation

We report a successful modification of the Damus-Kaye-Stansel operation for transposition of the great arteries when the coronary arteries are unsuitable for transfer. The procedure includes creation of a neoaorta with end-to-end anastomosis of the proximal pulmonary artery to the distal ascending aorta and creation of an aortopulmonary window between the proximal great arteries. A valved conduit is interposed between the right ventricle and the distal pulmonary artery.

Congenital euthyroid goitre with impaired thyroglobulin transport

A case of congenital goitre with defective thyroglobulin (Tg) synthesis was studied from the clinical, biochemical and morphological perspectives. The patient, 5.5-year-old boy, who was clinically euthyroid, showed a positive perchlorate discharge test (37.2%). However, the iodination system seemed to be normal since radioiodine uptake into the thyroid was very high, and inspection of the H2O2-generating system using thyroid slices and an assay for peroxidase activity in microsomes showed no abnormalities. On the other hand, virtually no Tg was detected in the serum, and the amount of Tg in thyroid tissue, estimated with gel electrophoresis, was below 10% of the normal value, the quality of Tg being unchanged. Morphological observations demonstrated the presence of Tg in the markedly distended rough endoplasmic reticulum of the cytoplasm of follicular cells and a lack of Tg in the colloid of the follicular lumen. These results suggest that the thyroid is defective in Tg synthesis, probably associated with impaired transport of Tg from the cells to the lumen.

Effect of FR128998, a novel PAF receptor antagonist, on endotoxin-induced disseminated intravascular coagulation

This study aimed to evaluate the effect of FR128998, (1s,6s)-1-benzyl-10-(3-pyridyl-methyl)-7-thia-10-azaspiro [5,6]-dodecan-11-one 7,7-dioxide hydrochloride, a novel platelet activating factor (PAF) receptor antagonist, on endotoxin lipopolysaccharide-induced disseminated intravascular coagulation in rats. Experimental disseminated intravascular coagulation was induced by an infusion of lipopolysaccharide at 0.25 mg/kg/h for 4 h. Simultaneous infusion of FR128998 (0.25 and 1.0 mg/kg/h) with lipopolysaccharide dose dependently inhibited thrombocytopenia, but not leukopenia. The changes in coagulation parameters of disseminated intravascular coagulation, i.e., prolongation of activated partial thromboplastin time and elevated levels of fibrinogen/fibrin degradation products, were also prevented by the treatment with FR128998. In addition, FR128998 attenuated the increase in serum tumor necrosis factor (TNF) which appeared during the initial stage of disseminated intravascular coagulation. FR128998 (10 microM) also inhibited the TNF production by peripheral blood leukocytes or alveolar macrophages stimulated by lipopolysaccharide in vitro. Furthermore, TNF production induced by PAF itself in vitro was also inhibited in the presence of FR128998. These data indicate that PAF plays a pivotal role in the development of disseminated intravascular coagulation via TNF production.

Structure and function of mannan-binding proteins isolated from human liver and serum

Mannan-binding proteins (MBPs) occur in two forms, both of which are synthesized in the liver. Although two different MBP cDNAs have been cloned and characterized for rat and mouse, only one form of human MBP cDNA has been isolated. In this study, two forms of human MBP, liver MBP (L-MBP) and serum MBP (S-MBP), were purified from liver and serum and characterized, respectively. The amino acid sequences of these two human MBPs were identical and consistent with those deduced from the cDNA sequence. The most significant difference between L-MBP and S-MBP was the number of subunits, which was about 9 in L-MBP and 18 in S-MBP. Furthermore, S-MBP but not L-MBP had the ability to activate the complement. These results suggested that a newly synthesized protein is processed post-translationally into two forms, S-MBP and L-MBP, in human liver. Recombinant MBP synthesized in COS-1 cells, after transfection with human MBP cDNA, was secreted into the medium, suggesting that COS-1 cells lack a mechanism for differentiating S-MBP and L-MBP. A mutant MBP synthesized in COS-1 cells which lacked a sequence comprising 9 amino acid residues at the beginning of the collagen-like domain had no ability to activate the complement, suggesting that this sequence plays an important role in the activation of the complement by human MBP.

Changes in microsomal lysophospholipid acyltransferase activity are correlated with rat parotid gland enlargement induced by chronic administration of isoproterenol

Chronic (5- and 10-day) administration of isoproterenol, an agent that induces the proliferation of salivary gland cells, produced increases in microsomal 1-acyl-sn-glycero-3-phosphate acyltransferase and 1-acyl-sn-glycero-3-phosphocholine acyltransferase activity in rat parotid glands in parallel with gland enlargement. This increased activity was reduced when the treatment was stopped, the reduction corresponding to the reduction in gland weight. There were significant correlations between lysophospholipid acyltransferase activity and gland weight, and between the activities of the two types of lysophospholipid acyltransferase. However, isoproterenol treatment did not affect any of the steps of the subsequent phospholipid N-methylation. These results suggest that the cell proliferation induced by chronic administration of isoproterenol in the parotid gland is accompanied by reversible and selective increases in microsomal lysophospholipid acyltransferases.

Presence of endogenous chemotactic factors for periodontal ligament cells in bovine cementum and bone

When bovine cementum and bone were subjected to sequential dissociative extraction first with 4 M guanidine HCl ('G' extract) and then with 4 M guanidine HCl/0.5 M EDTA ('E' extract), high chemotactic activities for periodontal ligament cells were detected in the 'G' extracts using modified Boyden chambers. The chemotactic activities in both tissue extracts were destroyed by trypsin and heat. However, the activities in bone extracts were more heat-stable than those in cementum. When both tissue extracts were separated into bound and unbound fractions by DEAE-Sephacel ion-exchange chromatography, the chemotactic activities in cementum were detected in the unbound fractions, and those in bone in the bound fractions, which were eluted by 1 M NaCl. These results suggest that cementum and bone contain different chemotactic protein factors for periodontal ligament cells.

Echocardiographic findings in 104 professional cyclists with follow-up study

To assess the effect of long-term athletic training on the heart, 104 professional cyclists and 40 sedentary controls (69 younger cyclists and 26 controls aged 20 to 39 and 35 older cyclists and 14 controls aged 40 to 60) were examined by using M-mode and pulsed Doppler echocardiography. Cyclists had larger and more hypertrophied left ventricle than did controls (p < 0.001) and had normal percentages of fractional shortening (%FS). The ratio of left ventricular late-to-early diastolic peak filling velocity (A/R) of younger cyclists was normal, but the A/R of older cyclists was larger than that of controls (p < 0.001). Of the 104 cyclists, 95 continued cycling and were reexamined 2 years later; 9 of 40 older cyclists retired and were reexamined 20 +/- 8 months after retirement. During the follow-up period for the active cyclists, left ventricular dilatation, hypertrophy, and %FS of both younger and older cyclists and the A/R of younger cyclists did not change. However, the A/R of older cyclists increased (p < 0.01). For the nine retired cyclists, left ventricular dimension decreased (p < 0.001), left ventricular wall thickness and %FS did not change, and A/R increased (p < 0.05) after retirement. We concluded that (1) cyclists had large and hypertrophied left ventricles with normal systolic function, and (2) some cyclists with long-term athletic training may have partly irreversible left ventricular hypertrophy with impaired left ventricular diastolic filling.

Characterization of microsomal long-chain acyl-CoA hydrolase activity in the rat submandibular gland

1. Long-chain fatty acyl-CoA hydrolase in submandibular gland microsomes was characterized and compared to that in liver ones. 2. In rat submandibular gland, the microsomal long-chain acyl-CoA hydrolase showed a higher relative activity for polyunsaturated fatty acyl-CoAs than that of liver microsomes. 3. It was suggested that the hydrolase in rat submandibular gland microsomes may play a role in modulation in the acyl-CoA pool size.

Localization of a low Mr GTP-binding protein, rap1 protein, in plasma membranes and secretory granule membranes of rat parotid gland

Subcellular fractions were prepared from rat parotid gland by sequential centrifugation, Percoll gradient centrifugation and divalent-cation precipitation, and the localization of a low Mr GTP-binding protein, rap1 protein (rap1p) was analyzed by immunoblotting using a specific antibody. rap1p was found to be located in apical and basolateral plasma membranes, and secretory granule membranes in rat parotid gland. On the other hand, the beta gamma subunits of heterotrimeric Gt protein was localized in plasma membranes but not in granule membranes.

[Reoperation with a bifurcated nonvalved extracardiac conduit for stenosis of the valved conduit and the pulmonary bifurcation after a Ross-Rastelli operation]

We report a case of successful reoperation with a bifurcated nonvalved extracardiac conduit for stenosis of the valved conduit and the pulmonary bifurcation after a Ross-Rastelli operation. The patient was 11-year-old female, who had undergone Ross-Rastelli operation with a 16 mm Carpentier-Edwards valved conduit for pulmonary atresia with ventricular septal defect at six year-old following Blalock-Taussig shunt at four year-old. She required reoperation for progressive right heart failure due to stenosis of the valved conduit and the pulmonary bifurcation. The reoperation was performed under cardiopulmonary bypass with aortic crossclamp. The stenosed valved conduit placed between the right ventricle and the right pulmonary artery was removed and replaced with 18 mm EPTFE graft. Because the direct repair of the pulmonary bifurcation stenosis was thought to be difficult, a 12 mm ringed EPTFE graft was anastomosed to the left pulmonary artery distal to the bifurcation stenosis as a branch of the 18 mm EPTFE main graft. Although transitional heart failure required IABP support in her early postoperative course, she subsequently recovered and discharged the hospital at the 37th postoperative day. Her right ventricular pressure reduced from 105 mmHg to 54 mmHg by the cardiac catheterization. She is now alive and well without any complaints.

The effect of recent advances in pharmacologic management on the prognosis of dilated cardiomyopathy

To determine the effect of recent advances in medical management on the survival of patients with dilated cardiomyopathy (DCM), 103 patients with DCM were studied. The subjects were divided into 3 groups based upon the time of initial medical treatment at our institute: Group I, between 1976 and 1981, 20 patients; Group II, between 1982 and 1985, 27 patients; and Group III, between 1986 and 1991, 56 patients. The clinical, Holter electrocardiographic and echocardiographic findings, the pharmacologic treatments used, and the clinical outcomes for the 3 groups of patients were compared. During the follow-up period, which averaged 27 months, 31 deaths related to cardiac disease occurred. The 4 year survival rate was 76% in Group III, 49% in Group II and 35% in Group I; the difference in survival rate between Groups I and III was significant (p < 0.01). At the initial evaluation, no differences were found among the 3 groups in the incidences of advanced heart failure (NYHA functional class III or IV), atrial fibrillation or complex ventricular arrhythmias. Neither diastolic blood pressure nor heart rate differed among the 3 groups, but Group III patients were older and had significantly higher systolic blood pressures than Group I patients (p < 0.05, for both comparisons). There were no differences among the 3 groups in % fractional shortening, left ventricular end-systolic wall stress or left ventricular wall thickness, but left ventricular dimensions were significantly smaller in Group III than in Group I (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The association of Helicobacter pylori with differentiated-type early gastric cancer

BACKGROUND

Recent studies have indicated that infection with Helicobacter pylori is closely associated with increased risk for gastric cancer. Previous studies, however, usually have been made on cases of advanced gastric cancer.

METHODS

The Congo red-methylene blue test was performed on 19 healthy subjects, 24 patients with early gastric cancer of differentiated type, and 17 patients with early cancer of undifferentiated type. H. pylori infection was examined by culture of biopsy specimens obtained from noncancerous antral mucosa.

RESULTS

H. pylori was detected in 19 (79%) of 24 patients with differentiated-type early gastric cancer, but in only 5 (29%) of 17 patients with undifferentiated-type early gastric cancer; this difference was statistically significant. It also was detected significantly more frequently in patients with differentiated cancers than in healthy subjects.

CONCLUSIONS

H. pylori infection was closely associated with differentiated-type gastric cancers, but not with undifferentiated types.

The association of Helicobacter pylori with differentiated-type early gastric cancer

BACKGROUND

Recent studies have indicated that infection with Helicobacter pylori is closely associated with increased risk for gastric cancer. Previous studies, however, usually have been made on cases of advanced gastric cancer.

METHODS

The Congo red-methylene blue test was performed on 19 healthy subjects, 24 patients with early gastric cancer of differentiated type, and 17 patients with early cancer of undifferentiated type. H. pylori infection was examined by culture of biopsy specimens obtained from noncancerous antral mucosa.

RESULTS

H. pylori was detected in 19 (79%) of 24 patients with differentiated-type early gastric cancer, but in only 5 (29%) of 17 patients with undifferentiated-type early gastric cancer; this difference was statistically significant. It also was detected significantly more frequently in patients with differentiated cancers than in healthy subjects.

CONCLUSIONS

H. pylori infection was closely associated with differentiated-type gastric cancers, but not with undifferentiated types.

Differentiation of conglutination activity and sugar-binding activity of conglutinin after removal of NH2-terminal 54 amino acid residues by endogenous serine protease(s)

Bovine conglutinin, which is a serum lectin specific for N-acetylglucosamine, was purified from heat-inactivated bovine serum by Sepharose 4B-mannan affinity chromatography. Without prior heat inactivation, however, the same affinity chromatography yielded a modified conglutinin, which retained sugar-binding, but not conglutination activity. The modified lectin was designated conglutinin-N. The conglutinin-N subunit (38 kDa) was smaller than that of conglutinin (45 kDa). The apparent molecular mass was also reduced from 1000 (conglutinin) to 600 kDa (conglutinin-N). Conglutinin-N and conglutinin reacted equally with a rabbit anti-conglutinin antiserum. Comparison of the NH2-terminal sequences of conglutinin-N with the primary structure of conglutinin [Lee, Y-M., Leiby, K. R. Allar, J., Paris, K., Lerch, B., and Okarma, T. B. (1991) J. Biol. Chem. 266, 2715-2723] revealed that the removal of the 54 NH2-terminal amino acids of conglutinin produced conglutinin-N. This conversion of conglutinin to conglutinin-N was catalyzed by the eluate fraction of the first affinity chromatography from untreated bovine serum and was inhibited by serine protease inhibitors such as [4-aminophenyl]methanesulfonyl fluoride and C1 inhibitor. Conglutinin-N had neither conglutination activity nor binding activity to the sensitized erythrocyte-solid phase iC3b complex (EAiC3b), although it retained the binding activity to mannan in solution and the original binding specificity for N-acetylglucosamine. Cross-linking showed that conglutinin-N formed trimers of the 38-kDa subunits, whereas conglutinin formed higher multimers of 9-18 mer. These results indicated that deleting the NH2-terminal portion containing three cysteine residues by endogenous serine protease(s) produced some conformational changes in the entire molecule, which resulted in the loss of binding activity to EAiC3b and retention of the sugar-binding property.

Heterogeneity and time course of improvement in cardiac function after cardioversion of chronic atrial fibrillation: assessment of serial echocardiographic indices

OBJECTIVE

To assess the clinical characteristics of patients in whom cardiac function improved after cardioversion of atrial fibrillation and the time course of the improvement.

DESIGN

A prospective serial study of echocardiograms recorded before cardioversion and one day, seven days, one month, and three months after cardioversion.

SETTING

Echocardiography laboratory of a university hospital.

PATIENTS

23 patients with chronic atrial fibrillation in whom cardioversion was successful.

MAIN OUTCOME MEASURES

M mode indices of the left ventricular wall motion and pulsed Doppler indices of the left ventricular inflow.

RESULTS

Three months after cardioversion percentage fractional shortening had increased by more than 5% in 14 patients (improved group) and by less than 5% in nine patients (non-improved group). Those in whom cardiac function improved had significantly higher heart rates and a greater reduction in ventricular filling during atrial fibrillation and a more prominent atrial filling wave three months after cardioversion than those patients in the non-improved group. Over the three months of follow up the mean (1SD) percentage fractional shortening increased from 22 (3)% to 30 (4)% in the improved group and in this group heart rate fell one day after cardioversion. A month after cardioversion the percentage fractional shortening had increased to 35 (5)% and the atrial systolic contribution to left ventricular filling increased from 30 (9)% on day 1 to 47 (12)%.

CONCLUSIONS

Cardioversion improved cardiac function in patients with tachycardia and reduced ventricular filling during atrial fibrillation. Because both an immediate reduction of heart rate and a delayed recovery of atrial booster pump function played an important part in the improvement of cardiac function the long-term effects of cardioversion should be assessed at least a month after cardioversion.

Two nonpeptide tachykinin antagonists act through epitopes on corresponding segments of the NK1 and NK2 receptors

The molecular mechanism of action for two chemically distinct and highly selective, nonpeptide antagonists, CP-96,345 and SR-48,968, was studied by development of a series of chimeric constructs between their respective target receptors, the NK1 (substance P) and NK2 (neurokinin A) receptors. The binding affinities of the natural peptide ligands, substance P and neurokinin A, were not affected by exchanging almost the entire C-terminal half of the NK1 receptor with the corresponding segment of the NK2 receptor. In contrast, it was found that transfer from the NK2 to the NK1 receptor of a segment corresponding to transmembrane segment VI, the amino-terminal half of transmembrane segment VII, and the connecting extracellular loop 3 completely switched the susceptibility for the nonpeptide antagonists. This chimeric exchange, corresponding to 17 nonconserved residues, conveyed full susceptibility for the NK2-specific compound SR-48,968 to the previously unresponsive NK1 receptor--i.e., the Ki value for inhibition of binding of 125I-labeled substance P decreased from > 10,000 to 0.97 nM. At the same time the affinity for the NK1-selective compound CP-96,345 decreased > 30-fold. The actual binding site for SR-48,968 was localized to this region of the NK2 receptor by use of [3H]SR-48,968, which did not bind to the NK1 receptor but bound with similar high affinities to the wild-type NK2 receptor and to the chimeric NK1 receptor with the NK2 receptor segment incorporated around transmembrane segments VI and VII, Kd = 1.5 nM and 1.0 nM, respectively. Our data indicate that two chemically very different nonpeptide antagonists, CP-96,345 and SR-48,968, act through epitopes located around transmembrane segment VI on their respective target receptors and that at least the nonconserved residues in these epitopes are not important for the binding of the natural peptide ligands, substance P and neurokinin A.

Capnocytophaga sputigena bacteremia associated with acute leukemia

During a three-year period, Capnocytophaga sputigena bacteremia occurred in three patients with acute leukemia receiving induction therapy on a hematology ward. Oral pathology such as periodontitis or severe mucositis was considered to be the most likely source of bacteremia. All three blood culture isolates were identified as that species by deoxyribonucleic acid (DNA) homology studies. Because of the phenotypical similarity of Capnocytophaga species, it is difficult to differentiate them by conventional bacteriological methods. All three isolates were susceptible to antibiotics active against most anaerobes. However, production of beta-lactamase was found in two isolates, one of which proved resistant to both piperacillin and ceftazidime. Therefore, the empiric use of imipenem or clindamycin may be justified in febrile granulocytopenic patients with cancer who develop significant oral lesions.

Pathological analysis of hypertrophic cardiomyopathy simulating dilated cardiomyopathy

The pathomorphologic features of hypertrophic cardiomyopathy simulating dilated cardiomyopathy in the late stage (HCM-DCM) were compared with those of ordinary hypertrophic cardiomyopathy (HCM). Seven autopsied hearts with HCM-DCM and 11 with HCM were assessed quantitatively using an image analyzer. Unlike HCM, significant left ventricular enlargement and wall thinning were observed in HCM-DCM, and the percentage areas of massive fibrosis and disarray were significantly greater. In HCM-DCM, the disarray was distributed diffusely, whereas massive fibrosis was distributed more intensively in the ventricular septum and anterior wall than in the lateral and posterior wall. Narrowing of intramyocardial small arteries was observed more frequently in HCM-DCM, especially in the ventricular septum and anterior wall, than in HCM. These results suggest that the enlargement and wall thinning of the left ventricle in HCM-DCM are attributable to non-uniform progression of massive fibrosis, which is closely related to small-arterial lesions.