[Obstructive sleep apnea syndrome: a cause of cognitive disorders in the elderly?]

Obstructive sleep apnea syndrome is a chronic disease characterized by repeated upper airway obstructions during sleep, resulting in fragmented sleep with arousals, nocturnal intermittent hypoxemia and diurnal dysfunctions. Despite its high prevalence in elderly, sleep apnea syndrome seems to be underestimated and difficult to be recognized because of the lack of clinical symptoms specificity in this population. Among the numerous consequences of the obstructive sleep apnea syndrome, cognitive impairment prevails on the attention, executive functions and memory. Neuroimaging studies in human and experimental models allowed to highlight neural correlates of these cognitive dysfunctions in obstructive sleep apnea syndrome. The obstructive sleep apnea syndrome with cognitive impairment shares some features with Alzheimer's disease, involving genetic predisposition ApoE4, hippocampus and synaptic plasticity abnormalities. In this context, the question arises whether obstructive sleep apnea syndrome is a possible etiological or aggravating factor of cognitive decline in elderly with mild cognitive impairment or Alzheimer's disease. Although there are conflicting results in studies evaluating therapeutic efficiency of continuous positive air pressure, obstructive sleep apnea syndrome seems nevertheless as a correctable factor, at least for its impact on some cognitive consequences. Looking for sleep apnea syndrome in elderly with cognitive decline should be considered in a global, diagnosis and therapeutic management.

Effects of bosentan on nondigital ulcers in patients with systemic sclerosis

BACKGROUND

Bosentan is an oral dual endothelin receptor antagonist, which has been shown to be efficacious for preventing new digital ulcers in patients with systemic sclerosis (SSc) in two high-quality randomized controlled trials. However, its efficacy for nondigital ulcers in SSc remains unknown.

OBJECTIVES

To evaluate the efficacy of bosentan on nondigital ulcers in patients with SSc.

METHODS

Bosentan was administered to five patients with SSc with pulmonary arterial hypertension, who also had nondigital ulcers refractory to conventional treatments. The efficacy of bosentan on nondigital ulcers and its association with clinical features of ulcers were analysed.

RESULTS

The nondigital ulcers refractory to conventional treatments were significantly improved by the administration of bosentan in cases surrounded with severe cyanosis. In contrast, nondigital ulcers without cyanosis were still refractory to bosentan therapy.

CONCLUSIONS

Bosentan may be efficacious for accelerating the healing of nondigital ulcers with severe cyanosis, suggesting that nondigital ulcers caused by severely impaired peripheral circulation are highly responsive to this treatment.

Measurement of short-chain fatty acids in human faeces using high-performance liquid chromatography: specimen stability

BACKGROUND

Short-chain fatty acids such as lactic acid produced by the intestinal bacterial flora have various physiological actions involved in health, and it is important to determine the concentrations of faecal short-chain fatty acids and evaluate their relationship with large intestinal diseases. In this study, we evaluated the highly selective and sensitive simultaneous measurement of both volatile and non-volatile short-chain fatty acid hydrazides using high-performance liquid chromatography (HPLC).

MATERIALS AND METHODS

Faeces treated with ethanol were used as analytic samples. Short-chain fatty acids were measured as fatty acid hydrazides by HPLC.

RESULTS

For 12 types of short-chain fatty acid, the results regarding linearity, recovery tests and reproducibility were favourable. Faeces treated with ethanol could be stored at room temperature.

DISCUSSION

The stability of short-chain fatty acids in faeces at room temperature was statistically analysed. Faeces stored without treatment with ethanol showed increases/decreases in the concentrations of short-chain fatty acids, which may be due to assimilation by intestinal bacteria. However, specimen in 70% ethanol and stored in room temperature exhibited no substantial changes in concentrations of short-chain fatty acids up to seven days.

Ets-1 is involved in transcriptional regulation of the chick inducible nitric oxide synthase gene in embryonic ventricular myocytes

In order to elucidate roles of Ets family of transcription factors in transcriptional activation of inducible nitric oxide synthase (iNOS) genes, we analyzed the chick iNOS gene expression in cultured chick embryonic ventricular myocytes (CEVM). Deletional analysis and site-directed mutagenesis demonstrated that both the Ets/PEA3 site (-221 to -216 bp) and the kappaB site (-101 to -93 bp) of the 5'-flanking region of the chick iNOS gene were involved in the maximal activation of the lipopolysaccharide (LPS)-induced expression of the reporter (luciferase) gene, although the proximal kappaB site played the more essential role. Electrophoretic mobility shift assay revealed that LPS augmented the nuclear protein bindings to the Ets/PEA3 as well as kappaB motifs. Ets-1, one of the Ets proteins, was suggested to be bound to the Ets/PEA3 oligonucleotide. By Northern blot analysis, LPS was shown to induce iNOS mRNA in CEVM, along with a preceding increase in the levels of c-ets-1 mRNA. Ets-1 may be involved in the iNOS gene transcription in CEVM, presumably through interacting with the NF-kappaB.

Regulation of thyroid hormone receptor isoforms in physiological and pathological cardiac hypertrophy

Physiological and pathological cardiac hypertrophy have directionally opposite changes in transcription of thyroid hormone (TH)-responsive genes, including alpha- and beta-myosin heavy chain (MyHC) and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), and TH treatment can reverse molecular and functional abnormalities in pathological hypertrophy, such as pressure overload. These findings suggest relative hypothyroidism in pathological hypertrophy, but serum levels of TH are usually normal. We studied the regulation of TH receptors (TRs) beta1, alpha1, and alpha2 in pathological and physiological rat cardiac hypertrophy models with hypothyroid- and hyperthyroid-like changes in the TH target genes, alpha- and beta-MyHC and SERCA. All 3 TR subtypes in myocytes were downregulated in 2 hypertrophy models with a hypothyroid-like mRNA phenotype, phenylephrine in culture and pressure overload in vivo. Myocyte TRbeta1 was upregulated in models with a hyperthyroid-like phenotype, TH (triiodothyronine, T3), in culture and exercise in vivo. In myocyte culture, TR overexpression, or excess T3, reversed the effects of phenylephrine on TH-responsive mRNAs and promoters. In addition, TR cotransfection and treatment with the TRbeta1-selective agonist GC-1 suggested different functional coupling of the TR isoforms, TRbeta1 to transcription of beta-MyHC, SERCA, and TRbeta1, and TRalpha1 to alpha-MyHC transcription and increased myocyte size. We conclude that TR isoforms have distinct regulation and function in rat cardiac myocytes. Changes in myocyte TR levels can explain in part the characteristic molecular phenotypes in physiological and pathological cardiac hypertrophy.

Prognostic factors for survival and bladder recurrence in transitional cell carcinoma of the upper urinary tract

BACKGROUND

Prognostic factors for survival in transitional cell carcinoma of the upper urinary tract have been extensively evaluated, but detailed analyses of patterns of bladder recurrence after surgery have been rare.

METHODS

The outcome and tumor recurrence of 93 patients with transitional cell carcinoma of the upper urinary tract surgically treated between 1975 and 1999 were reviewed, retrospectively. Disease-specific survival by pathologic stage and grade were analyzed by the Kaplan-Meier

METHOD

Prognostic factors for survival and bladder recurrence were examined by univariate and multivariate analysis.

RESULTS

The 5-year disease-specific survival rates of the patients with pTa, T1 and T2 were 92.9%, 100% and 88.9%, respectively. However, that of the pT3 patients was 61.9% and the median survival of the pT4 cases was only 7 months. Bladder recurrence was seen in 40 cases and recurrences occurred within 1 year in 32 of these patients. The stage and grade of metachronous bladder tumors usually resembled those of primary tumors, but invasive recurrences were seen in 19% of recurrent cases with primary pTa, pT1 tumors. The significant prognostic factor for survival was pathologic stage (pT3, pT4), but no significant variables were detected for bladder recurrence by multivariate analysis.

CONCLUSIONS

The prognosis of pT3, pT4 patients is poor and effective systemic adjuvant therapy is necessary. Invasive bladder recurrence occurred in 19% of patients with superficial primary tumors. As no significant prognostic variables for bladder recurrence were identified, careful follow up for bladder recurrence is important even if the primary tumors are non-invasive.

Cloning of hypoxia-inducible factor 1alpha cDNA from chick embryonic ventricular myocytes

Hypoxia-inducible factor 1 (HIF-1) is composed of HIF-1alpha and arylhydrocarbon nuclear receptor translocator (ARNT), which belong to the basic-helix-loop-helix-Per/ARNT/Sim (bHLH-PAS) family of transcription factors. HIF plays key roles in oxygen homeostasis and embryonic cardiovascular development. In this study, we have cloned cDNAs encoding the chick HIF-1alpha from cultured embryonic ventricular myocytes (CEVM) and then examined its expression in various embryonic tissues. The deduced amino acid sequence of the chick HIF-1alpha cDNA showed 79% identity with that of the human HIF-1alpha cDNA. In contrast, sequence homology between the chick HIF-1alpha and endothelial PAS protein 1 (EPAS1), another member of the bHLH-PAS proteins, was only low (49%). HIF-1alpha mRNA was expressed abundantly in CEVM, but scarcely in the liver, which was quite different from expression pattern of EPAS1 mRNA. These data suggest that HIF-1alpha may be involved in embryonic cardiovascular development. HIF-1alpha and EPAS1 may play distinct roles during developmental stages.