Case report: alternating exit sites in reentry circuit of ventricular tachycardia with nonischemic cardiomyopathy - relationship between ablation site and inner loop

We present a patient with nonischemic cardiomyopathy who had ventricular tachycardia (VT) with QRS morphology alternans. VTs of two QRS morphologies (VT1 and VT2) exhibiting a right bundle branch block pattern with inferior axis was induced by ventricular pacing. The morphology of the QRS complex during VT1 exhibited more distinctively inferior axis than those during VT2. Induced VTs had similar morphologies to clinically the documented VTs. Pacemapping at anterolateral site of the left ventricle during sinus rhythm produced the same QRS complex of VT1 in a surface 12-lead electrocardiogram. A mapping study was performed with an electrode catheter located at the same site of LV during sustained VT1. The analysis of the local electrograms and postpacing interval during concealed entrainment at the catheter mapping revealed this pacing site was at the inner loop of the reentry circuit. Radiofrequency catheter ablation was performed at this site. The morphology of VT1 changed to different QRS morphology (VT2) during the first delivery of radiofrequency energy and was terminated after 20 seconds of the application. Then VT with alternans of QRS morphology and cycle length of VT1 and VT2 was induced by ventricular pacing, and was abolished by the second application of radiofrequency energy at this same site, suggesting that this site was located in the exit site close to inner loop of the reentry circuit and the alternans of QRS morphology was linked to the change of exit site.

Noninvasive assessment of arterial distensibility in adolescents using the second derivative of photoplethysmogram waveform

To clarify the clinical usefulness of the second derivative of the waveform of the fingertip photoplethysmogram (SDPTG), we examined the relationship between the pattern of the SDPTG waveform and risk factors related to atherosclerosis in 1,495 boys and girls aged 9-17 years. The fingertip photoplethysmogram and its second derivative wave were automatically recorded from the second digit of the right hand with the subjects lying in a supine position. The SDPTG waveform consisted of a, b, c and d waves in systole and an e wave in diastole. The heights of the a and d waves were measured from the baseline, and the ratio of the height of the d wave to that of the a wave (d/a ratio) was calculated. The d/a ratio had a negative correlation with the systolic (SBP) and diastolic blood pressures (DBP), atherogenic index (AI) and immunoreactive insulin concentrations (IRI) after adjustment for age. Multiple linear regression analysis revealed that the d/a ratio was associated more with body height than the risk factors for atherosclerosis in boys and girls at the growth period. The effect of sex- and height-specific cutoff values of the 10th percentile for the d/a ratio was therefore tested. The results showed that subjects with d/a ratios lower than the 10th percentile had significantly higher SBP, DBP, AI and IRI values compared to those with higher d/a ratios. These findings suggest that differences in the length of the vascular system, which are related to increases in body height, may modify the SDPTG waveform pattern during adolescence. When the body height as well as age and sex is adequately allowed for, the d/a ratio may be useful for the evaluation of arterial distensibility and for identification of individuals at an increased risk of developing atherosclerosis.

Effects of antihypertensive agents on blood pressure during exercise

The relationship between blood pressure (BP) and cardiovascular morbidity has been appreciated for many years. Casual BP may not be representative of the pressure at other times. It is recognized that BP during exercise may be a more accurate predictor than casual BP. There is, however, little information about the effects of antihypertensive drugs on the BP during exercise. This study was designed to investigate the effects of various antihypertensive agents on BP during exercise. Sixty-four patients (age, 49+/-10 years) with untreated essential hypertension (WHO I, II) were studied during a supine ergometric exercise regimen. A graded exercise test was started at a workload of 50 W, and the load was increased by 25 W every 3 min. The hemodynamic responses to exercise were evaluated by changes in systolic and diastolic BP (SBP, DBP) and heart rate (HR). Plasma norepinephrine (NE) levels were measured at rest and during submaximal exercise, and before and after 4 weeks of treatment with metoprolol (METO), doxazosin (DOXA), trichlormethiazide (TCTZ), nifedipine (NIFE), amlodipine (AMLO) and temocapril (TEMO) between left ventricular mass index (LVMI) and BP values at rest, during exercise, and during the recovery period after exercise were assessed by multiple regression analysis. The stepwise selection (forward conditional) method showed that LVMI was significantly associated with SBP during submaximal exercise and during the recovery period. All antihypertensive treatments decreased SBP and DBP (p<0.01) at rest. METO, AMLO and TEMO significantly lowered SBP (p<0.05) during exercise, whereas DOXA, TCTZ and NIFE induced no change in SBP. The exercise-induced increase of plasma NE was further enhanced by METO and NIFE but not by AMLO, DOXA, or TCTZ, and it was significantly suppressed by TEMO (p<0.01). These results suggest that BP during exercise is more highly associated with the progression of left ventricular hypertrophy (LVH) than is casual BP. Because antihypertensive agents differ in their effects on exercise hemodynamics, we recommend that hemodynamic factors during exercise be considered when selecting the optimal antihypertensive medication for highly active patients.

Targeted disruption of Col11a2 produces a mild cartilage phenotype in transgenic mice: comparison with the human disorder otospondylomegaepiphyseal dysplasia (OSMED)

Transgenic mice were prepared by homologous recombination with a Col11a2 targeting gene in which an inverted neomycin-resistant gene was inserted between restriction sites in exons 27 and 28. The targeted allele was transcribed in shortened mRNAs, which could be detected by Northern blotting. However, translation of the full-length Col11a2 chain was unable to occur because of the presence of premature termination codons within the inverted neomycin-resistant gene. Analysis of pepsin-resistant collagen chains from rib cartilage of homozygous mice demonstrated the lack of synthesis of intact alpha2(XI) chains. However, pepsin-resistant collagen chains of either alpha1(XI) or alpha1(V) were still detected on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Therefore, alpha2(XI) chains are not essential for the assembly of some molecular forms of triple-helical type V/XI collagen. The phenotype was milder than in the cho/cho mouse in which, as the result of mutation, translation of the full-length alpha1(XI) chain fails to occur and the mice die at birth (Li et al., 1995). Homozygous mice without expression of an alpha2(XI) chain had a smaller body size, receding snouts, and deafness. Nasal bones in the homozygous transgenic mice were specifically shorter and dimpled on their external surfaces. Chondrocytes in growth plates of all long bones were markedly disorganized and failed to align in columns. Analysis of growth plates from transgenic mice by in situ hybridization showed expression of alpha1(II) and alpha1(XI) but not of alpha1(I) or alpha1(V) which, in contrast, were expressed in the developing bone and in the bone collar. Expression of alpha1(X) specifically in the hypertrophic cartilage was observed in normal and transgenic mice. No obvious osteoarthritis was observed throughout the life of homozygous mice up to 1 year of age, although minor morphologic anomalies in the articular cartilages were discernible. The mild phenotype is consistent with similar mutations in the COL11A2 gene seen in patients with nonocular Stickler syndrome and some patients with otospondylomegaepiphyseal dysplasia (OSMED), as well as in patients with a nonsyndromic form of deafness called DFNA13.

Culturally verified Mycoplasma pneumoniae pneumonia in Japan: a long-term observation from 1979-99

We describe the prevalence of community-acquired M. pneumoniae pneumonia diagnosed by culture methods in a single institute in Japan from January 1979 to December 1999. Cultures were performed in 2971 pneumonia cases and yielded M. Pneumoniae in 508 cases. The epidemic peaks recurred regularly at 4-year intervals (1980, 84, 88 and 91-2). Although a large epidemic has not occurred since 1992, traces of epidemic periodicity have still persisted from 1992 to 1999 at 3-year intervals.

Efficacy of transthoracic needle aspiration in community-acquired pneumonia

OBJECTIVE

To evaluate the indications, efficacy, and safety of transthoracic needle aspiration (TNA) in diagnosing community-acquired pneumonia (CAP).

METHODS

TNA procedure was performed using an ultrathin needle with ultrasonography and/or computed tomography. The aspirate samples were Gram-stained and sent for cultures. The results were compared with those from conventional microbiological studies.

PATIENTS

Sixty patients with CAP who were admitted to the hospital and were studied prospectively between July 1994 and June 1999 were included in the study.

RESULTS

TNA culture was positive in 30 cases (50.0%). Streptococcus pneumoniae was the most frequently isolated pathogen, followed by the Streptococcus milleri group, and anaerobes. The results of TNA were consistent with those of quantitative sputum cultures in 9 patients and with those of blood cultures in 4. Complications arose in 3 patients who developed small to moderate pneumothorax.

CONCLUSIONS

TNA is a safe procedure with a good diagnostic yield. In particular, anaerobes or microaerophils such as the S. milleri group were highly detectable by TNA. The results obtained by TNA were highly consistent with those obtained by the gold standard methods. Combined with conventional methods, TNA is considered highly useful for determining the etiology of CAP.

Regulation of the yeast Yap1p nuclear export signal is mediated by redox signal-induced reversible disulfide bond formation

Yap1p, a crucial transcription factor in the oxidative stress response of Saccharomyces cerevisiae, is transported in and out of the nucleus under nonstress conditions. The nuclear export step is specifically inhibited by H(2)O(2) or the thiol oxidant diamide, resulting in Yap1p nuclear accumulation and induction of transcription of its target genes. Here we provide evidence for sensing of H(2)O(2) and diamide mediated by disulfide bond formation in the C-terminal cysteine-rich region (c-CRD), which contains 3 conserved cysteines and the nuclear export signal (NES). The H(2)O(2) or diamide-induced oxidation of the c-CRD in vivo correlates with induced Yap1p nuclear localization. Both were initiated within 1 min of application of oxidative stress, before the intracellular redox status of thioredoxin and glutathione was affected. The cysteine residues in the middle region of Yap1p (n-CRD) are required for prolonged nuclear localization of Yap1p in response to H(2)O(2) and are thus also required for maximum transcriptional activity. Using mass spectrometry analysis, the H(2)O(2)-induced oxidation of the c-CRD in vitro was detected as an intramolecular disulfide linkage between the first (Cys(598)) and second (Cys(620)) cysteine residues; this linkage could be reduced by thioredoxin. In contrast, diamide induced each pair of disulfide linkage in the c-CRD, but in this case the cysteine residues in the n-CRD appeared to be dispensable for the response. Our data provide evidence for molecular mechanisms of redox signal sensing through the thiol-disulfide redox cycle coupled with the thioredoxin system in the Yap1p NES.

Roles of alpha(1) and alpha(1)/beta subunits derived from cardiac L-type Ca(2+) channels on voltage-dependent facilitation mechanisms

Strong depolarization pulses facilitate L-type Ca(2+) channels in various cell types including cardiac myocytes. The mechanisms underlying prepulse facilitation are controversial with respect to the requirements for channel subunits, cAMP-dependent protein kinase, and additional anchor proteins. The properties of voltage-dependent facilitation of the L-type Ca(2+) channel was studied in recombinant cardiac alpha(1) subunits with or without cardiac beta subunit, expressed in Chinese hamster fibroblast cells. The magnitude of voltage-dependent I(Ba) facilitation in the alpha(1) subunit channel is dependent on the duration of the prepulse as well as on the interval duration between prepulse and test pulse. The characteristics of this facilitation were not affected by coexpression of the beta subunit. These results indicate that cardiac alpha(1) subunits exhibit voltage-dependent facilitation because of their own intrinsic structure, independent of any other accessory subunit or additional regulatory proteins, and that cardiac beta subunits have no essential regulatory role at the onset or continuance of the voltage-dependent facilitation.

Polymorphic ventricular tachycardia in patients with vasospastic angina--clinical and electrocardiographic characteristics and long-term outcome

There have been few clinical studies exploring the characteristics of spontaneous polymorphic ventricular tachycardia (VT) during a vasospastic angina attack. During a 4-year recruitment period, Holter ECG recordings were monitored for 42+/-24 h during a drug-free period in 60 consecutive patients with vasospastic angina (VSA) and of these, 8 patients had at least one episode of polymorphic VT during monitoring. Ischemic ST segment elevation was immediately preceded the spontaneous polymorphic VT in all 8 patients, 4 of whom had silent coronary vasospasm. Immediately before the onset of polymorphic VT, both R-on-T and long-short sequences were observed in 4 of the 8 patients and ST wave alternans were recorded in 2 patients. VT exhibited a pattern of torsade de pointes in 4 of the 8 patients. Five patients underwent electrophysiologic testing during a drug-free asymptomatic phase, and polymorphic VT was induced in 2 of the 5 patients, with one developing ventricular fibrillation. During a follow-up period of 73+/-17 months, there was a significant difference in the incidence of sudden death between patients with and without VT (2/8 cases [25%] vs 0/52 [0%]; p<0.01). Thus, vasospastic attacks, even if asymptomatic, that immediately precede the development of polymorphic VT may be associated with a repolarization abnormality and an increased risk of sudden death.

Orbital inflammatory pseudotumor and ischemic vasculitis in Churg-Strauss syndrome: report of two cases and review of the literature

OBJECTIVE

To clarify the characteristics of ocular manifestations in Churg-Strauss syndrome (allergic granulomatosis and angiitis).

DESIGN

Two interventional case reports and literature review.

PARTICIPANTS

Two patients with Churg-Strauss syndrome with ocular manifestations are described; 15 previously reported cases and the present 2 cases of Churg-Strauss syndrome with ocular manifestations are reviewed.

INTERVENTION

Ocular manifestations were divided into two groups: orbital inflammatory pseudotumor and ischemic vasculitis.

MAIN OUTCOME MEASURES

The onset, conjunctival involvement, orbital imaging, antineutrophil cytoplasmic antibodies (ANCA), and visual prognosis were evaluated.

RESULTS

The characteristics of the orbital inflammatory pseudotumor type (eight cases) are chronic onset, positive conjunctival involvement, abnormalities in orbital imaging studies, negative ANCA, and good visual prognosis. The ischemic type (nine cases) is characterized by sudden onset, no conjunctival involvement or abnormalities in imaging studies, positive ANCA, and occasional poor visual prognosis.

CONCLUSIONS

Orbital inflammatory pseudotumor and ischemic vasculitis may represent two essential characteristics of Churg-Strauss syndrome, granulomatosis and angiitis, respectively. The clinical features of the two types are so distinct that differentiation may be meaningful for diagnosis and treatment of Churg-Strauss syndrome with ocular manifestations.

Differential biosynthesis of polysialic or disialic acid Structure by ST8Sia II and ST8Sia IV

ST8Sia II (STX) and ST8Sia IV (PST) are polysialic acid (polySia) synthases that catalyze polySia formation of neural cell adhesion molecule (NCAM) in vivo and in vitro. It still remains unclear how these structurally similar enzymes act differently in vivo. In the present study, we performed the enzymatic characterization of ST8Sia II and IV; both ST8Sia II and IV have pH optima of 5.8-6.1 and have no requirement of metal ions. Because the pH dependence of ST8Sia II and IV enzyme activities and the pK profile of His residues are similar, we hypothesized that a histidine residue would be involved in their catalytic activity. There is a conserved His residue (cf. His(348) in ST8Sia II and His(331) in ST8Sia IV, respectively) within the sialyl motif VS in all sialyltransferase genes cloned to date. Mutant ST8Sia II and IV enzymes in which this His residue was changed to Lys showed no detectable enzyme activity, even though they were folded correctly and could bind to CDP-hexanolamine, suggesting the importance of the His residue for their catalytic activity. Next, the degrees of polymerization of polySia in NCAM catalyzed by ST8Sia II and IV were compared. ST8Sia IV catalyzed larger polySia formation of NCAM than ST8Sia II. We also analyzed the (auto)polysialylated enzymes themselves. Interestingly, when ST8Sia II or IV itself was sialylated under conditions for polysialylation, the disialylated compound was the major product, even though polysialylated compounds were also observed. These results suggested that both ST8Sia II and IV catalyze polySia synthesis toward preferred acceptor substrates such as NCAM, whereas they mainly catalyze disialylation, similarly to ST8Sia III, toward unfavorable substrates such as enzyme themselves.

Nicorandil increases adenosine 5'-monophosphate-primed interstitial adenosine via activation of ecto-5'-nucleotidase in rat hearts

With the use of microdialysis techniques, we examined the effects of nicorandil, a hybrid of an ATP-sensitive K+ (K ATP) channel opener and a nitrate compound, on the production of interstitial adenosine in rat hearts in situ. The level of dialysate adenosine measured under a constant supply of adenosine 5'-monophosphate (AMP) reflected the activity of endogenous ecto-5'-nucleotidase. Nicorandil (0.3-3mM) increased the level of AMP (100 microM)-primed dialysate adenosine in a concentration-dependent manner, and this effect was completely abolished by the guanylate cyclase inhibitor, methylene blue (100 microM), but not by the K ATP channel blocker, glibenclamide (10 microM). Another K ATP channel opener, cromakalim (0.1-1mM), did not increase the production of AMP-primed dialysate adenosine. These results suggest that nicorandil increases the level of interstitial adenosine via cyclic guanosine monophosphate-mediated activation of ecto-5'-nucleotidase.

Hypopituitarism due to pituitary metastasis of lung cancer: case of a 21-year-old man

A 21-year-old man presented persistent dry cough, general malaise, loss of appetite, decreased sexual desire and double vision. Chest radiograph revealed a mass shadow in the left upper lobe. Histopathological diagnosis of the tumor was squamous cell carcinoma. Brain computed tomography and magnetic resonance imaging revealed a metastasis to the pituitary gland. Hypopituitarism was diagnosed by pituitary function tests. Diabetes insipidus was absent and the function of the posterior lobe of the pituitary gland was preserved. Hypopituitarism due to pituitary metastasis is a rare complication of lung cancer, and has never been reported in a patient as young as 21 years old.

Transgenic mice with inactive alleles for procollagen N-proteinase (ADAMTS-2) develop fragile skin and male sterility

Transgenic mice were prepared with inactive alleles for procollagen N-proteinase (ADAMTS-2; where ADAMTS stands for a disintegrin and metalloproteinase with thrombospondin repeats). Homozygous mice were grossly normal at birth, but after 1-2 months they developed thin skin that tore after gentle handling. Although the gene was inactivated, a large fraction of the N-propeptides of type I procollagen in skin and the N-propeptides of type II procollagen in cartilage were cleaved. Therefore the results suggested the tissues contained one or more additional enzymes that slowly process the proteins. Electron microscopy did not reveal any defects in the morphology of collagen fibrils in newborn mice. However, in two-month-old mice, the collagen fibrils in skin were seen as bizarre curls in cross-section and the mean diameters of the fibrils were approx. half of the controls. Although a portion of the N-propeptides of type II procollagen in cartilage were not cleaved, no defects in the morphology of the fibrils were seen by electron microscopy or by polarized-light microscopy. Female homozygous mice were fertile, but male mice were sterile with a marked decrease in testicular sperm. Therefore the results indicated that ADAMTS-2 plays an essential role in the maturation of spermatogonia.

Protein kinase C isoform-dependent modulation of ATP-sensitive K+ channels during reoxygenation in guinea-pig ventricular myocytes

ATP-sensitive K+ (KATP) channels activated by glucose-free anoxia close immediately upon reoxygenation in single guinea-pig ventricular myocytes, while KATP channels open persistently during reperfusion in coronary-perfused guinea-pig ventricular myocardium. To investigate the reasons behind this discrepancy, we investigated whether protein kinase C (PKC) modulates the opening of KATP channels during anoxia-reoxygenation and ischaemia-reperfusion. Exposure of guinea-pig ventricular cells to glucose-free anoxia shortened the action potential duration at 90% repolarisation (APD90) and evoked the glibenclamide-sensitive robust outward current (IK,ATP). Subsequent reoxygenation caused an immediate prolongation of APD90 and a decrease in IK,ATP within approximately 20 s. When the novel (Ca2+-independent) PKC was activated by applying 1,2-dioctanoyl-sn-glycerol (1,2DOG, 20 M) with EGTA (20 mM) in the pipette, the APD90 restored gradually after reoxygenation and the extent of recovery was appoximately 80% of the pre-anoxic value. Moreover, IK,ATP decreased slowly and remained opened for up to approximately 4 min after reoxygenation. These results suggest persistent opening of KATP channels during reoxygenation. The persistent activation of KATP channels was augmented when both novel and conventional (Ca2+-dependent) isoforms of PKC were activated by applying 1,2DOG without EGTA in the pipette. In coronary-perfused right ventricular myocardium, APD90 remained shortened for up to approximately 30 min of reperfusion. The gradual restoration of APD90 after ischaemia-reperfusion was facilitated by the KATP channel blocker glibenclamide and by the potent PKC inhibitor chelerythrine. Our results provide the first evidence that PKC activation contributes to the persistent opening of KATP channels during reoxygenation and reperfusion. We also conclude that both novel and conventional PKC isoforms co-operatively modulate the opening of KATP channels during the early phase of reoxygenation.

Inactivation of one allele of the type II collagen gene alters the collagen network in murine articular cartilage and makes cartilage softer

OBJECTIVE

To evaluate the influence of inactivation of one allele ("heterozygous knockout" or "heterozygous inactivation") of the type II procollagen gene (Col2a1) on the biomechanical properties and structure of the articular cartilage and subchondral bone in 15 month old mice.

METHODS

Indentation stiffness of the humerus head articular cartilage was measured by a microindentation method. Cartilage and subchondral bone were prepared for digital densitometry of proteoglycans (PGs), polarised light microscopy (PLM) of collagen, and osteoarthrosis (OA) grading.

RESULTS

Heterozygous inactivation of the Col2a1 gene softened articular cartilage (p=0.002) as measured by indentation stiffness ((mean (SEM) 0.50 (0.07) MPa v 0.94 (0.13) MPa in controls). Fibrillar collagen network exhibited lower birefringence in the intermediate (p=0.04) and deep zones (p=0.01) of cartilage by PLM, indicating either decreased collagen content or a lower degree of fibril parallelism in the knockout mice. The total and zonal thicknesses of articular cartilage were unchanged. Zonal PG contents did not differ significantly. In knockout mice, the prevalence of superficial fibrillation-that is, a sign of OA, was higher than in controls (73% v 21%, p=0.002). The collagen induced birefringence of the superficial zone was not reduced. The subchondral bone volume fraction was lower in knockout mice than in controls, 31% v 43% (p=0.01), and optical retardation values in PLM of bone collagen were slightly but significantly lower (p=0.01).

CONCLUSION

Heterozygous inactivation of the Col2a1 gene made articular cartilage softer, altered the collagenous network, reduced subchondral bone volume, and altered its microstructure. Changes in the cartilage collagen network probably contributed to increased susceptibility to OA.

Alterations in electrical and mechanical activity in Langendorff-perfused guinea pig hearts exposed to decreased external sodium concentration with or without hypotonic insult

In order to examine electrical and mechanical effects of hyponatremia and hypotonicity, relevant to those in patients with 'water intoxication' syndrome, Langendorff-perfused guinea pig hearts were exposed to reduced NaCl concentrations (hypotonic [NaCl](0)-reduction) under the monitoring of left ventricular developed pressure (LVDP) and epicardial ECG. In some hearts, hyponatremia (from 140 to 80 mEq/l) was compensated for by adding mannitol to maintain osmolarity at a constant level (isotonic [NaCl](0)-reduction) or tetraethylammonium chloride to maintain both osmolarity and chloride concentrations at a constant level (isotonic [Na(+)](0)-reduction). Progressive isotonic [NaCl](0)-reduction increased LVDP, which was abolished in the presence of KB-R7943, a novel inhibitor of Na(+)/Ca(2+)-exchange. LVDP was reduced in hypotonic [NaCl](0)-reduction in which myocardial water content was increased. PQ interval and QRS duration were prolonged with both hypotonic and isotonic [NaCl](0)-reduction and these changes tended to be more pronounced with hypotonic than with isotonic [NaCl](0)-reduction. Similar ECG changes were also evident with isotonic [Na(+)](0)-reduction. Gd(3+) (1-5 µM), a blocker of stretch-activated nonspecific cation channels, had no substantial effects on the electrical or mechanical changes seen with hypotonic [NaCl](0)-reduction. In conclusion, isotonic [NaCl](0)-reduction produced a positive inotropism by modulating Na(+)/Ca(2+)-exchange, whereas hypotonic [NaCl](0)-reduction led to negative inotropism, due in part to hypotonic myocardial swelling. In addition, [Na(+)](0)-reduction, irrespective of the concomitant [Cl(-)](0) or osmotic changes, depressed atrioventricular as well as intraventricular conduction.

[Clinical comparison of Chlamydia pneumoniae pneumonia, ornithosis, and Mycoplasma pneumoniae pneumonia]

To elucidate the differences between the clinical aspects of Chlamydia pneumoniae (C. pn) pneumonia and those of two other atypical pneumonias, Chlamydia psittaci (C. ps) pneumonia and Mycoplasma pneumoniae (M. pn) pneumonia, we analyzed the symptoms and laboratory data on the cases of these three types of pneumonia: 46 cases of C. pn pneumonia, 39 cases of C. ps pneumonia, and 131 cases of M. pn pneumonia. C. pn pneumonia was significantly more frequent among the elderly (mean 70 +/- 16 years, p < 0.01) and patients were significantly more likely to be male (76%, p < 0.05). A white blood cell count of over 10,000 was seen in 46% of C. pn pneumonia cases, a higher proportion than those of C. ps pneumonia (15%, p = 0.03) or M. pn pneumonia (18%, p = 0.006) cases. The proportions of patients with these infections who had an elevated GOT or GPT were not significantly different. Maximum body temperature was higher in M. pn pneumonia than in C. pn pneumonia (p = 0.003). Purulent sputa were seen in 44% of C. pn pneumonia cases and 50% of M. pn pneumonia cases, and these rates were higher than that of 13% in C. ps pneumonia cases (p = 0.002, p = 0.004). Dyspnea and anorexia symptoms were the most frequent in C. pn pneumonia cases (24% and 29%, respectively, the highest of all three pneumonias). There were clinical differences between C. pn pneumonia and the other two atypical pneumonias. However, there was some difficulty in differentiating between C. pn pneumonia and typical bacterial pneumonia because mixed infections were common (24%) in C. pn pneumonia cases.

Supernatant protein factor, which stimulates the conversion of squalene to lanosterol, is a cytosolic squalene transfer protein and enhances cholesterol biosynthesis

Squalene epoxidase, a membrane-associated enzyme that converts squalene to squalene 2,3-oxide, plays an important role in the maintenance of cholesterol homeostasis. In 1957, Bloch and colleagues identified a factor from rat liver cytosol termed "supernatant protein factor (SPF)," which promotes the squalene epoxidation catalyzed by rat liver microsomes with oxygen, NADPH, FAD, and phospholipid [Tchen, T. T. & Bloch, K. (1957) J. Biol. Chem. 226, 921-930]. Although purification of SPF by 11,000-fold was reported, no information is so far available on the primary structure or biological function of SPF. Here we report the cDNA cloning and expression of SPF from rat and human. The encoded protein of 403 amino acids belongs to a family of cytosolic lipid-binding/transfer proteins such as alpha-tocopherol transfer protein, cellular retinal binding protein, yeast phosphatidylinositol transfer protein (Sec14p), and squid retinal binding protein. Recombinant SPF produced in Escherichia coli enhances microsomal squalene epoxidase activity and promotes intermembrane transfer of squalene in vitro. SPF mRNA is expressed abundantly in the liver and small intestine, both of which are important sites of cholesterol biosynthesis. SPF is expressed significantly in isolated hepatocytes, but the expression level was markedly decreased after 48 h of in vitro culture. Moreover, SPF was not detectable in most of the cell lines tested, including HepG2 and McARH7777 hepatomas. Transfection of SPF cDNA in McARH7777 significantly stimulated de novo cholesterol biosynthesis. These data suggest that SPF is a cytosolic squalene transfer protein capable of regulating cholesterol biosynthesis.

More knee joint osteoarthritis (OA) in mice after inactivation of one allele of type II procollagen gene but less OA after lifelong voluntary wheel running exercise

OBJECTIVE

To investigate the incidence and severity of osteoarthritis (OA) and the effects of voluntary wheel running in normal mice and mice carrying either a targeted inactivation of one allele, heterozygous 'knockout', of Col2a1 gene or both alleles, homozygous 'knockout', of Col11a2 gene.

METHODS

Mice lived until 15 months of age in individual cages. Running activity was recorded around the clock. OA changes were evaluated from serial knee joint sections by light microscopy.

RESULTS

Heterozygous inactivation of Col2a1 gene coding for type II procollagen made the cartilage more susceptible to OA. At 15 months of age, OA prevalence was 60-90% in knockouts and 20-45% in normal controls (P < 0.01-0.001). Unexpectedly, a reduction of OA due to wheel running was observed in both knockout strains (P< 0.05-0.01). This effect was most evident in the femoral condyles. Incidence of OA in runners was approximately 50-85% of that in sedentary littermates. OA prevalence was higher in normal control and runner mice with high body weight. Running did not affect OA development in normal mice.

CONCLUSION

Heterozygous knockout of Col2a1 gene increased the OA prevalence in mice. Lifelong voluntary wheel running had a protective effect against OA in both knockout mice lines. The reason for this remains unknown. Reduction of OA may result from the reorganization and strengthening of the articular cartilage collagen network and/or adjacent muscles due to running, or lower body weight. Increased compliance of the articular cartilage and bones of the knockout mice may also contribute to the reduction of OA in exercised animals.

Chemical characterisation of the oligosaccharides in hooded seal (Cystophora cristata) and Australian fur seal (Arctocephalus pusillus doriferus) milk

Carbohydrates were extracted from hooded seal milk, Crystophora cristata (family Phocidae). Free oligosaccharides were separated by gel filtration and then purified by ion exchange chromatography, gel filtration and preparative thin layer or paper chromatography and their structures determined by 1H-NMR. The hooded seal milk was found to contain inositol and at least nine oligosaccharides, most of which had lacto-N-neotetraose or lacto-N-neohexaose as core units, similar to those in milk of other species of Carnivora such as bears (Ursidae). Their structures were as follows: Gal(beta1-4)Glc (lactose); Fuc(alpha1-2)Gal(beta1-4)Glc (2'-fucosyllactose); Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (lacto-N-neotetraose); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (lacto-N-fucopentaose IV); Gal(beta1-4)GlcNAc(beta1-3)[Gal(beta1-4)GlcNAc(beta1-6)]Gal(1-4)Glc (lacto-N-neohexaose); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)[Gal(beta1-4)GlcNAc(beta1-6)]Gal(beta1-4)Glc (monofucosyl lacto-N-neohexaose a); Gal(beta1-4)GlcNAc(beta1-3)[Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-6)]Gal(beta1-4)Glc (monofucosyl lacto-N-neohexaose b); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)[Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-6)]Gal(beta1-4)Glc (difucosyl lacto-N-neohexaose); Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (para lacto-N-neohexaose); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (monofucosyl para lacto-N-neohexaose). Milk of the Australian fur seal, Arctophalus pusillus doriferus (family Otariidae) contained inositol but no lactose or free oligosaccharides. These results, therefore, support the hypothesis that the milk of otariids, unlike that of phocids, contains no free reducing saccharides.

Increase in tonsillar germinal centre B-1 cell numbers in IgA nephropathy (IgAN) patients and reduced susceptibility to Fas-mediated apoptosis

IgAN is a common form of primary glomerulonephritis and also a disease of tonsillar focal infection. The comprehensive mechanism underlying this disease remains to be defined. To better understand its pathogenesis, we investigated tonsillar CD5+ B cells (B-1 cells) with respect to IgA synthesis. Germinal centre (GC) B cells were isolated from the tonsils of IgAN patients and the number of B-1 cells in the GC determined by flow cytometry. GC B-1 and B-2 (CD5- B) cells were purified by cell sorter, the cells were incubated with agonist anti-CD40 MoAb and the ability for antibody production by B-1 and B-2 cells determined by ELISPOT assay. GC B-1 cells and B-2 cells were incubated with agonist anti-Fas MoAb, and apoptosis in GC B-1 cells and B-2 cells was analysed by flow cytometry. Although B-1 cells do not usually take part in the GC reaction, an increase in B-1 cell numbers was observed in the GC of tonsils from IgAN patients. These B-1 cells were likely IgA1 antibody-producing cells, since the prominent IgA subclass in IgAN is generally considered to be IgA1. Although Fas-dependent apoptosis is essential for the elimination of activated B cells, these B-1 cells showed a reduced susceptibility to Fas-mediated apoptosis. It is conceivable that activated B-1 cells may survive in the GC due to impaired apoptosis and thus produce abnormal antibodies. These findings suggest that the immune responses of B-1 cells in the tonsillar GC could thus have an impact on the pathogenesis of IgAN.

Alpha-tocopherol transfer protein is important for the normal development of placental labyrinthine trophoblasts in mice

Alpha-tocopherol transfer protein (alpha-TTP), a cytosolic protein that specifically binds alpha-tocopherol, is known as a product of the causative gene in patients with ataxia that is associated with vitamin E deficiency. Targeted disruption of the alpha-TTP gene revealed that alpha-tocopherol concentration in the circulation was regulated by alpha-TTP expression levels. Male alpha-TTP(-/-) mice were fertile; however, placentas of pregnant alpha-TTP(-/-) females were severely impaired with marked reduction of labyrinthine trophoblasts, and the embryos died at mid-gestation even when fertilized eggs of alpha-TTP(+/+) mice were transferred into alpha-TTP(-/-) recipients. The use of excess alpha-tocopherol or a synthetic antioxidant (BO-653) dietary supplement by alpha-TTP(-/-) females prevented placental failure and allowed full-term pregnancies. In alpha-TTP(+/+) animals, alpha-TTP gene expression was observed in the uterus, and its level transiently increased after implantation (4.5 days postcoitum). Our results suggest that oxidative stress in the labyrinth region of the placenta is protected by vitamin E during development and that in addition to the hepatic alpha-TTP, which governs plasma alpha-tocopherol level, the uterine alpha-TTP may also play an important role in supplying this vitamin.

Hypoglycemic effect of cibenzoline in patients with abnormal glucose tolerance and frequent ventricular arrhythmias

While some antiarrhythmic agents have potential hypoglycemic effects and indeed some reports of hypoglycemic adverse effect of those drugs, no systematic reports have been issued. We studied the hypoglycemic effects of cibenzoline, a class I antiarrhythmic agent. Cibenzoline succinate (150-300 mg/day) was given orally for 12 weeks to 10 patients who had ventricular premature complexes (VPCs) of >1000 per 24 hours and abnormal glucose tolerance before treatment with cibenzoline. Abnormal glucose tolerance, judged by a 75-g oral glucose tolerance test (OGTT), was defined as the response designated as "diabetic" or "borderline" type according to the criteria specified by the Japan Diabetes Society. In OGTT, the insulinogenic index (defined as the ratio of the increment of IRI [immunoreactive insulin] to that of plasma glucose at 30 minutes after a glucose load) and the sum of IRI (sigma IRI) were also determined. Holter ECG recordings, OGTT, and measurements of fasting plasma glucose IRI, and HbA(1c) were performed before and during cibenzoline treatment. Cibenzoline caused VPC reduction of >70% in 6 of the 10 patients. The drug significantly decreased fasting plasma glucose and HbA(1c) (mean +/- SD) 12 weeks after treatment, from 6.18 +/-0.92 mM/L to 5.54 +/- 1.08 mM/L and from 6.17 +/- 1.03% to 5.83 +/- 0.96%, respectively (P < 0.05). While it significantly increased fasting IRI from 4.99 +/- 1.50 to 6.51 +/- 1.47 microU/mL (P < 0.01), the insulinogenic index from 0.33 +/- 0.26 to 0.65 +/- 0.38 (P < 0.05), and sigma IRI from 168 +/- 67 microU/mL to 199 +/-46 (P < 0.05). Cibenzoline exerted a hypoglycemic effect, facilitating insulin secretion in patients with abnormal glucose tolerance and ventricular arrhythmias.