In situ Ca2+ dynamics of Purkinje fibers and its interconnection with subjacent ventricular myocytes

Purkinje fibers play essential roles in impulse propagation to the ventricles, and their functional impairment can become arrhythmogenic. However, little is known about precise spatiotemporal pattern(s) of interconnection between Purkinje-fiber network and the underlying ventricular myocardium within the heart. To address this issue, we simultaneously visualized intracellular Ca(2+) dynamics at Purkinje fibers and subjacent ventricular myocytes in Langendorff-perfused rat hearts using multi-pinhole type, rapid-scanning confocal microscopy. Under recording of electrocardiogram at room temperature spatiotemporal changes in fluo3-fluorescence intensity were visualized on the subendocardial region of the right-ventricular septum. Staining of the heart with either fluo3, acetylthiocholine iodide (ATCHI), or di-4-ANEPPS revealed characteristic structures of Purkinje fibers. During sinus rhythm (about 60 bpm) or atrial pacing (up to 3 Hz) each Purkinje-fiber exhibited spatiotemporally synchronous Ca(2+) transients nearly simultaneously to ventricular excitation. Ca(2+) transients in individual fibers were still synchronized within the Purkinje-fiber network not only under high-K(+) (8 mM) perfusion-induced Purkinje-to-ventricular (P-V) conduction delay, but also under unidirectional, orthodromic P-V block produced by 10-mM K(+) perfusion. While spontaneous, asynchronous intracellular Ca(2+) waves were identified in injured fibers of Purkinje network locally, surrounding fibers still exhibited Ca(2+) transients synchronously to ventricular excitation. In summary, these results are the first demonstration of intracellular Ca(2+) dynamics in the Purkinje-fiber network in situ. The synchronous Ca(2+) transients, preserved even under P-V conduction disturbances or under emergence of Ca(2+) waves, imply a syncytial role of Purkinje fibers as a specialized conduction system, whereas unidirectional block at P-V junctions indicates a substrate for reentrant arrhythmias.     

Colonoscopic Stigmata of 1 mm or Deeper Submucosal Invasion in Colorectal Cancer

Purpose  This study was designed to identify colonoscopic stigmata, indicating substantial invasion into the submucosa by T1 colorectal cancer with sessile morphology, including both flat and protruded types. Methods  A total of 111 Tis or T1 colorectal cancers were studied retrospectively. The lesions were divided into two groups: Group A (n = 83), Tis or T1 cancers with <1 mm submucosal invasion; and Group B (n = 28), T1 cancers with a ≥1 mm submucosal invasion. Printed photographs of the lesions were reviewed by five experienced colonoscopists who were blinded to histology. Deep depression, irregular surface, ulceration or erosion, fold convergence, and spontaneous bleeding were independently evaluated. Findings considered present by three or more reviewers were defined as positive. Kappa analysis was used to measure inter/intraobserver variability. Results  Positive rates of four findings but not fold convergence were significantly higher in Group B than in Group A. Irregular surface and spontaneous bleeding were significant independent predictors of ≥1 mm submucosal invasion, with diagnostic accuracies of 85.6 and 76.6 percent, respectively. Kappa analysis demonstrated fair-to-good inter/intraobserver agreement for spontaneous bleeding and fair-to-good intraobserver agreement for irregular surface. Conclusions  Irregular surface and spontaneous bleeding were colonoscopic stigmata, indicating ≥1 mm submucosal invasion in T1 colorectal cancer.     

Nasal CPAP improves the quality of life and lessens the depressive symptoms in patients with obstructive sleep apnea syndrome

OBJECTIVE: To assess changes in response to nasal continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome (OSAS) concerning excessive daytime sleepiness (EDS), depressive state, and quality of life (QOL). PATIENTS AND METHODS: We assessed for EDS using the Epworth sleepiness scale (ESS), for mood using The Zung self-depression scale (SDS), and for QOL using Short-Form 36 (SF-36) in 132 patients with obstructive sleep apnea syndrome (OSAS) and control subjects. Patients had severe OSAS (apnea-hypopnea index, 59.4+/-23.8/h) and were more hypersomnolent and depressed, and had poorer QOL than 38 age- and gender-matched controls. RESULTS: Before treatment most QOL domains in the SF-36 were significantly associated with patients' SDS scores. With nasal CPAP, ESS and SDS scores were respectively decreased from 9.7+/-4.5 to 4.0+/-2.4 (p<0.0001) and from 49.2+/-10.4 to 45.1+/-9.6 (p<0.0005). Total SF-36 score and scores for seven of eight domains were increased significantly with treatment. Thus, nasal CPAP lessens EDS and depression, and improves QOL, in patients with severe OSAS. Further, magnitudes of changes in total SF-36 scores and in five of eight domains correlated significantly with magnitude of change in SDS score upon nasal CPAP treatment. No relationship was evident between treatment-associated score changes in SF-36 domains and ESS score change. CONCLUSION: Although patients with severe OSAS have poorer QOL than control subjects, nasal CPAP appears to improve QOL by alleviating depression.     

Carboxylic monolayer formation for observation of intracellular structures in HeLa cells with direct electron beam excitation-assisted fluorescence microscopy

Intracellular structures of HeLa cells are observed using a direct electron beam excitation-assisted fluorescence (D-EXA) microscope. In this microscope, a silicon nitride membrane is used as a culture plate, which typically has a low biocompatibility between the sample and the silicon nitride surface to prevent the HeLa cells from adhering strongly to the surface. In this work, the surface of silicon nitride is modified to allow strong cell attachment, which enables high-resolution observation of intracellular structures and an increased signal-to-noise ratio. In addition, the penetration depth of the electron beam is evaluated using Monte Carlo simulations. We can conclude from the results of the observations and simulations that the surface modification technique is promising for the observation of intracellular structures using the D-EXA microscope.OCIS codes: (170.0170) Medical optics and biotechnology, (170.0180) Microscopy     

Isolated ACTH deficiency with Graves' disease: a case report

A 60-year-old man was hospitalized with complaints of general malaise and weight loss. On admission, ACTH and cortisol levels were low, and thyroid function tests revealed hyperthyroidism. These findings and further examination led to a diagnosis of isolated ACTH deficiency (IAD) with Graves' disease. It is known that IAD is frequently associated with thyroid disease, but its association with Graves' disease is rare. The present case is worth noting, because some reports indicate that aggravation of associated Graves' disease may concomitantly aggravate adrenal insufficiency in patients with IAD.     

Granulocytic sarcoma of the colon in chronic myelomonocytic leukemia

A 59-year-old man with a six-month history of chronic myelomonocytic leukemia (CMML) was admitted to the Kitasato University Hospital because of melena in September 2000. Colonofiberscopy and barium enema demonstrated an ulcerated tumorous lesion in the transverse colon. The histopathologic findings of the ulcer bed revealed diffuse infiltration of granulocytes at each stage of differentiation. The diagnosis of granulocytic sarcoma (GS) was made. Surgical resection was not indicated, because thrombocytopenia was hardly improved enough to allow surgery despite repetitive transfusion of platelet concentrates. CMML developed to refractory anemia with excess of blast in transformation in February 2001. Two courses of low dose cytarabine plus aclarubicin were ineffective on the GS in spite of a decrease in the peripheral blood blasts. Progression to acute myeloid leukemia eventually broke out, in July 2001. The patient died of leukemia complicated with pneumonia and intestinal obstruction. At present, nine cases of GS in the colon have been reported. However, these cases did not include CMML. This is the first report describing GS in the colon associated with CMML.