Different time course of changes in sarcoplasmic reticulum and myosin isoforms in rat soleus muscle at early stage of hyperthyroidism.

AIMS AND METHODS: We studied changes in the expression of myosin and sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) and in Ca2+ uptake and release rates by the SR in rat slow-twitch soleus muscles treated with thyroid hormone (3,5,3'-triiodo-l-thyronine, T3) for 1, 3, 7 and 21 days. RESULTS: The content of fast SR Ca2+-ATPase isoform SERCA1a protein significantly increased as early as 3 days of T3 treatment, while a rise in fast myosin heavy chain isoforms was found only 21 days after the onset of T3 administration. T3-induced slow-to-fast transitions were much less pronounced in myosin light chain than in myosin heavy chain. Moreover, in vitro measurements of SR Ca2+-handling capacity with indo-1 indicated that increases in uptake rate preceded those of release rate (7 vs. 21 days). CONCLUSION: These data suggest that changes in the myosin and SERCA expressions seem not to occur in a coordinated manner at the early stage of hyperthyroidism and that intervention with T3 may temporarily produce slow-twitch type I fibres which contain, in addition to slow SERCA2a isoform, the appreciable amounts of fast SERCA1a isoform. Moreover, it is speculated that some fibres in the hyperthyroid soleus muscles may temporarily acquire unique contractile properties distinct from normal fast and slow fibres.

Bonding abutments to cast metal post/cores: comparison of pre-treatment effects.

Bond strengths were evaluated for (1) metal primer systems when the metal was contaminated by a dentin conditioner and (2) a dentin adhesive system when dentin was contaminated by metal primers. Disc specimens were cast in a silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy and dentin specimens were prepared by grinding the labial surface of bovine teeth. Specimens were treated with (1) metal primer alone, (2) dentin conditioner alone, (3) metal primer followed by dentin conditioner and (4) dentin conditioner followed by metal primer. A resin cement was poured into a mould over a restricted bonding area and allowed to set. Metal specimens were shear stressed to failure after thermocycling (4-60 degrees C; 20,000 cycles). Dentin specimens were stressed in the same manner after 24 h of immersion in 37 degrees C water. The results were compiled and analysed by anova. Data for dentin specimens treated with dentin conditioner only or with the combination of dentin conditioner and metal primer were not significantly different, statistically. Post-thermocycled groups indicated that bond strengths to the alloy significantly decreased (P < 0.05) when the primed metal surface was contaminated with dentin conditioner regardless of the timing of its application.

Activated astrocytes with glycogen accumulation in ischemic penumbra during the early stage of brain infarction: immunohistochemical and electron microscopic studies.

Brain infarction was induced in rats by injection of microspheres through the right internal carotid artery, and structural changes in the astrocytes were observed during the early period following the infarction. Necrotic foci, varying in size and shape, were found in the right hemisphere. After immunohistochemical staining for GFAP, GFAP-positive astrocytes in the perinecrotic area known as the ischemic penumbra had distinctly increased in number and size with elongation of cytoplasmic processes 3 days after infarction. Electron microscopic observation revealed that glycogen granules had markedly accumulated in the cytoplasm of astrocytes located in the ischemic penumbra 3 and 5 days after infarction. Seven days after infarction, however, the glycogen granules disappeared from the astrocytes. Intermediate filaments increasingly appeared in the protoplasmic astrocytes after 3 days and were abundant in the activated and hypertrophied astrocytes after 7 days. As a result of our present study, we conclude that: (1) the function of glucose uptake from blood vessels was not impaired in the astrocytes under hypoxic conditions; (2) the astrocytes actively ingested blood glucose through the endothelial cells and accumulated it as glycogen for activation of their functions, and the cell volume increased under hypoxic conditions; (3) the depression of energy metabolism and the decrease in the uptake of energy sources in the nerve cells promoted glycogen accumulation in the astrocytes under hypoxic conditions; (4) intermediate filaments (GFAP filaments) increased in number, coincident with the activation and enlargement of the astrocytes; and (5) protoplasmic astrocytes were transformed into fibrous astrocytes in the ischemic penumbra of the brain infarction.

Measuring reduced cytochrome aa3 in cadaveric lungs using near-infrared spectroscopy.

Researchers are investigating the use of cadaveric lungs to make up for the shortage of donors. However, no method to enable accurate evaluation of cadaveric lung viability has been established. We designed the present study to evaluate the viability of cadaveric lung tissue using near-infrared spectroscopy (NIRS). Male Lewis rats were anesthetized, mechanically ventilated, and subjected to a left thoracotomy. After cardiac arrest induced by an injection of sodium pentobarbital, we continued mechanical ventilation using oxygen (Group 1, n = 16) or nitrogen (Group 2, n = 20). Using NIRS, we monitored the redox state of cytochrome aa3 at intervals of 20 minutes for a period of 5 hours. We harvested the lung tissues of each group at 2 and 5 hours post-mortem and performed pathologic examination. The reduced cytochrome aa3 in Group 2 increased from 2 hours post-mortem. We observed no significant changes in Group 1. We found and scored the formation of hyaline membranes, intra-alveolar edema, edema around bronchioles and small vessels, and congestion in the cadaveric lungs. In Group 1, histologic findings were mild to moderate. In Group 2, findings were moderate at 2 hours post-mortem but became much more severe at 5 hours post-mortem. The measurement of reduced cytochrome aa3 using NIRS may reflect the histologic condition of cadaveric lung tissue. We expect that this evaluation method will be advantageous for lung transplantation in the future.

Rotational acetabular osteotomy for severely dysplastic acetabulum.

The operative procedures chosen for arthrosis with severe acetabular dysplasia vary among orthopaedic surgeons. We operated on 250 hips using the rotational acetabular osteotomy (RAO) method of Ninomiya and Tagawa [8]. In this report, we describe the technique of RAO and the results of this procedure in patients with severely dysplastic hips. Among the 250 hips, there were 6 which were classified as Severin group V. In those hips, the CE angle was less than 0 degrees, and the femoral head showed superolateral subluxation. After acetabular osteotomy with straight and curved osteotomes, smooth inferolateral rotation could be done in all cases. At the latest follow-up symptoms were improved remarkably, especially pain. Radiographically, adequate coverage of the femoral head was achieved and joint congruence improved in all 6 hips.

Light and electron microscopic study of peripheral nerve damage in patients with lepromatous leprosy (LL) and borderline lepromatous leprosy (BL).

Cutaneous branches of radial nerves in patients with lepromatous leprosy (LL) and borderline lepromatous (BL) were studied by light and electron microscopy. Foamy macrophages were found more or less in the nerve fibers of all leprosy patients and distributed in the epineurial, perineurial and endoneurial areas. In the endoneurium, the foamy macrophages were mainly located in the subperineurial and perivascular spaces. Vacuolated Schwann cells were also found in the nerve fasciculus. In electron microscopy, these foamy macrophages and vacuolated Schwann cells contained numerous small dense materials, irregular in size and shape, considered to be degenerated and fragmented mycobacterium leprae. These dense materials were found also in the cytoplasm of vascular endothelial cells. These findings suggest that mycobacteria enter into the endoneurium via the blood vessels. In our present study, on the other hand, it was very difficult to find the intact mycobacteria in the cytoplasm of the foamy macrophages, Schwann cells or endothelial cells, as well as in the Ziehl-Neelsen staining of paraffin sections. The disappearance of intact bacilli in our present study might have been caused by multi drug therapy. The myelinated nerve fibers were degenerated and disappeared in variable degrees. Degenerative changes of the myelin sheath developed from the outer layer to the inner layer with disarrangement of the lamellar structure. These findings were different from myelin destruction of peripheral nerves in Wallerian degeneration. The degenerative changes of the myelin sheath are caused by degeneration and destruction of Schwann cells in leprosy patients. Fibrosis surrounding myelinated and unmyelinated nerve fibers, i.e., periaxonal fibrosis, was found to a greater or lesser extent in the endoneurium. In the present study, it is still unclear whether the periaxonal fibrosis was due to necrosis of the Schwann cells by infection of mycobacteria or to an autoimmune mechanism such as antiperipheral nerve antibody. However, lamellated concentric fibrosis surrounding regenerative myelinated and unmyelinated nerve fibers with the disappearance of mycobacteria suggests that degenerations and regenerations of nerve axons were repeated during clinical cause. These findings indicated that autoimmune mechanisms play an important role in the pathogenesis of periaxonal fibrosis.

Is communication to endocardium necessary for angiogenesis in transmyocardial laser revascularization?

There is evidence of angiogenesis being induced after transmyocardial laser revascularization (TMLR), although the precise mechanism has not been fully elucidated. This study was designed to examine whether or not blood flow from the left ventricle through the channels is essential for angiogenesis following TMLR. Ten dogs underwent the creation of two types of laser channels in the left ventricle: 1) a transmural channel (TMC), which penetrates the myocardium, and 2) a non-transmural channel (NTMC), which does not open to the epicardium. The animals were sacrificed on the 28th postoperative day and the vascular density was examined. Vessels with smooth muscle media were seen within or around the channel remnant. The vessel density was compared between TMC and NTMC. The outer and inner halves of the myocardium in the TMC region were compared in the same way. The density of vessels within and around the channel remnants was significantly higher in TMC than in NTMC (1.439 versus 0.685 vessels/microscopic visual field (mvf=40X); p=0.0025). The vascular density was significantly higher in the region adjacent to TMC than in a distant region (>3 mm from the channel center). The vascular density was significantly higher in the outer half than in the inner half of the myocardium (1.730 versus 1.180 vessels/mvf: p=0.0459). These findings demonstrate that communication to the left ventricular lumen enhances angiogenesis of TMLR, although blood flow in the channel did not exist 4 weeks after TMLR and angiogenesis tended to be more highly enhanced in the outer half than in the inner half of the myocardium.

Revision surgery after triple-cup arthroplasty.

Although various operative procedures have been applied for advanced or terminal osteoarthritis of the hip joints in relatively young patients, the long-term results are controversial. Since 1974, we have performed the triple-cup arthroplasty developed by Aoki in 110 patients who were comparatively young. The triple-cup assembly is composed of stainless-steel outer and inner cups between which a high density polyethylene cup is incorporated, so that there are basically four mobile surfaces, but the major movement is actually taking place between the outer cup and the plastic cup [8]. We have sometimes encountered migration of the cups, which caused hip joint pain and decreased the range of motion. Revision surgery was required for 25 hip joints in 21 patients (23%). The acetabulum was very thin in almost all cases, so that reaming of the cavity had to be restricted to the minimum possible. The femoral head in the cup was often covered with a layer of fibrous tissue. We could utilize the femoral head as a bone graft, even though the residual volume of bone varied in each case. The result of revision surgeries after the triple-cup arthroplasty was good clinically and radiographically at last follow-up.

Effects of complement suppression on xenograft survival in hyperacute rejection.

To examine the significance of complement in discordant cardiac xenograft rejection, morphological changes in the rejection reaction were investigated following administration of FUT-175 (FUT), an anticomplement reagent. Guinea pigs were the cardiac donors, and Wistar rats were the recipients. Four groups of rats were constituted as follows: Group 0 was the control group. FUT of 40 mg/kg was injected intraperitoneally in group I. It was followed by continuous intravenous infusion (20 and 40 mg/kg/hr) in groups II and III. In one series, the effects of FUT on complement suppression was examined. In the FUT groups of rats (groups I to III), the serum levels of CH50 and ACH50 were measured at 0, 1, 2 and 4 hr following injection of FUT. In the second series of rats with identical treatments, the graft heart beating time following cardiac transplantation was measured. Cardiac transplantation into untreated rats was also performed as a control (group 0). In another series, the graft hearts in the FUT groups were extracted after 15, 30, 60 and 90 min of coronary reperfusion for morphological examination with scanning electron microscopy. The complement levels decreased significantly in the FUT-treated rats in a dose-dependent manner. Although the graft heart beating times in the FUT-treated groups were significantly longer than in group 0 (103, 106, and 112 min versus 14.7 min, p < 0.01), there was no significant difference in the graft heart beating time or in the morphological changes among the three FUT groups. Our results suggest the presence of factors other than complements contribute to the cardiac xenograft rejection.

The significance of atrial monophasic action potentials for monitoring rat cardiac allograft rejection.

BACKGROUND: Changes in the monophasic action potential may be used for detecting early acute rejection in the transplanted rat heart. METHODS: Heterotopic heart transplantations were performed in allogeneic and syngeneic rats. During atrial pacing, monophasic action potentials were simultaneously recorded in the right atrium and ventricle of the transplanted hearts on postoperative days 1, 3, and 5. The amplitude and duration of monophasic action potentials, atrioventricular conduction time, and cardiac intervals were analyzed. Histopathologic examination for rejection was performed on postoperative days 1, 3, and 5. RESULTS: In the allogeneic group, monophasic action potential amplitude progressively decreased, and monophasic action potential duration gradually increased after heart transplantation in the atrium and ventricle. With rejection, the amplitude decreased to a greater extent, and monophasic action potential duration increased to a greater extent in the atrium than in the ventricle on day 3. The atrioventricular conduction time increased on day 5, but the cardiac interval did not change. An inverse correlation between histopathologic grade and the monophasic action potential amplitude, and a positive correlation between histopathologic grade and the monophasic action potential duration existed for both the atrium and ventricle. These electrophysiologic and histopathologic changes were not observed in the syngeneic group. CONCLUSIONS: We conclude that right atrial monophasic action potentials may be a useful and reliable indicator of early acute heart transplant rejection.

A randomized trial of a consultation service to reduce falls in nursing homes.

CONTEXT: Falls are a major health problem in nursing homes, but no interventions have been shown to prevent falls in nursing home residents. OBJECTIVE: To evaluate an intervention program designed to prevent falls and associated injuries in high-risk nursing home residents. DESIGN: Randomized controlled trial. SETTING AND PARTICIPANTS: Seven pairs of middle Tennessee nursing homes with 1 facility in each pair randomly assigned to the intervention. Facilities had 482 (261 control, 221 intervention) residents who qualified for the study because they had high risk of falls and a potential safety problem that could be addressed by the intervention. INTERVENTION: Comprehensive structured individual assessment with specific safety recommendations that targeted suboptimal practices for environmental and personal safety, wheelchair use, psychotropic drug use, and transferring and ambulation. Facility staff were encouraged to implement the individual recommendations and to improve overall facility safety. MAIN OUTCOME MEASURES: The mean proportion of recurrent fallers and incidence rate of injurious falls in the facility in the year following the intervention. RESULTS: The mean proportion of recurrent fallers in intervention facilities (43.8%) was 19.1% (95% confidence interval, 2.4%-35.8%) lower than that in control facilities (54.1%, P=.03). Intervention facilities had a nonsignificant trend toward a lower mean rate of injurious falls (13.7 vs 19.9 per 100 person-years, reduction of 31.2%, P=.22). Subgroup analyses suggested greatest benefits for residents for whom the recommended interventions were carried out or who had 3 or more falls in the preceding year. CONCLUSION: The high rate of falls and related injuries in nursing homes should not be viewed as inevitable, but as outcomes that can be substantially improved through structured safety programs.

Papillary adenocarcinoma of the sigmoid colon associated with psammoma bodies and hyaline globules: report of a case.

We report a case of papillary adenocarcinoma of the sigmoid colon with psammoma bodies and intracytoplasmic hyaline globules. The patient was a 59-year-old woman. The tumor showed central ulceration with smooth elevated ridges. Histologically, the tumor was composed of numerous large irregular tubular structures accompanying infolded papillary growth. The tumor cells showed cytoplasmic basophilia and prominent nuclear atypia. Psammomatous-type calcification was scattered in the tumor stroma as well as in the glandular lumina. In addition, intracytoplasmic hyaline globules of various sizes were seen in the neoplastic cells. We propose the name papillary adenocarcinoma associated with psammoma bodies and hyaline globules for this tumor. Accumulation of further cases is needed to clarify the clinical significance of this type of tumor.

Protective effect of beraprost sodium, a stable prostacyclin analogue, on cardiac allograft vasculopathy in rats.

Intimal thickening and luminal narrowing of the coronary arteries are insidious complications of cardiac allograft. However, the pathogenesis of cardiac allograft vasculopathy (CAV) remains to be clarified. In this study, the protective effect of a prostacyclin analogue (beraprost sodium; BPS) on CAV was evaluated after heterotopic cardiac transplantation in rat. All recipients were treated with cyclosporine A (10 mg/kg/day intramuscularly). Eight rats received oral therapy with BPS of 50 micrograms/kg/day (BPS group) and another 8 rats received vehicle only (control group). All surviving cardiac grafts were removed on the 60th postoperative day and were examined to determine the severities of cellular rejection and CAV (> 50 microns in diameter). Additionally, 6-keto-prostagrandin F1 alpha and thromboxane B2 were compared between the two groups. There was no significant difference in the grading score for cellular rejection based on the ISHLT grading system (2.31 +/- 0.75 vs 2.47 +/- 0.65, p = 0.81). Although the endothelial cells were preserved in both groups, a deposition of fibrin-like dense materials was recognized in the subendothelial layers of the control group, but not in the BPS group. Intimal thickening was inhibited significantly in the BPS group. The intimal ratio (intimal area/sectional area of artery) was significantly lower in the BPS group than in the control group (0.134 +/- 0.03 vs 0.205 +/- 0.047; p < 0.01), without any difference in the medial ratio (medial area/sectional area of artery). alpha-actin positive smooth muscle cells (SMC) in intima were fewer in number in the BPS group than in the control group. The plasma thromboxane B2 level was significantly lower in the BPS group than in the control group (270 +/- 116 pg/ml vs 585 +/- 258 pg/mg; p < 0.01). It was concluded that BPS suppressed CAV development after heterotopic allogenic cardiac transplantation in rats.

Beneficial effects of perfluorotributylamine/pluronic F-68 stem-emulsion (FC43se) on discordant lung xenografts.

The aim of this study was to assess the effectiveness of Perfluorotributylamine/Pluronic F-68 Stem-Emulsion (FC43se) against hyperacute rejection in rabbit-pig xenodiscordant transplantation in an ex-vivo lung model. Rabbits were divided into two groups. In Group 1 (control), after extraction, the lungs were connected directly to the experimental circuit as soon as possible. The lungs were then perfused with 100 ml of pig blood only. In Group 2 (FC(+) Group), after extraction, the lungs were connected to the same circuit as soon as possible. The lungs were then perfused with 10 ml of FC43se plus 90 ml of pig blood. The duration of perfusion was defined from when the perfusion started until the PAP reached 50 mmHg. Significant differences in survival were seen between Group 1 and Group 2: in Group 1, the survival time was 51.9 +/- 16.8 min, whereas in Group 2 the survival time was 76.9 +/- 12.4 min (p < 0.01). The wet-to-dry weight ratio after 30 min of perfusion in Group 2 was significantly lower than that of Group 1 and the mean pulmonary artery pressure of Group 2 at 35, 40 and 45 min after perfusion was significantly lower than that of Group 1. Histological examination revealed that FC43se suppressed the adhesion of leukocytes to the surfaces of endothelial cells, and also attenuated the intimal edematous changes accompanying leukocyte infiltration. Therefore, FC43se has a beneficial effect on suppressing hyperacute rejection in xenogeneic discordant lung transplantation.

Ammonia determination as an early indicator in experimental superior mesenteric artery occlusion.

Superior mesenteric artery occlusion (SMAO) is often fatal. An indicator which enables the early diagnosis of SMAO is needed. As we think putrefaction products must appear and increase in the blood and ascites in SMAO, changes in the concentrations of ammonia, one of the putrefaction products, were measured in this study. Thirteen adult mongrel dogs were used for the in vitro experiment. The jejunum, ileum, and ascending colon were resected and incubated in saline. Changes in ammonia concentrations in the saline were examined at various incubation times. In the in vivo experiment, 11 mongrel dogs comprised the SMAO group and another 10 mongrel dogs comprised the control group. Changes in ammonia concentrations in the blood and ascites were examined in both groups. In the in vitro experiment, ammonia concentrations in the saline bath increased in all samples. It was highest in the sample from around the ascending colon, and lowest from around the jejunum. However, at the end of experiment, this difference became insignificant. In the in vivo experiment, ammonia concentrations in samples of the blood increased early and significantly in the SMAO group, compared with the control group. Ammonia concentrations in samples of the ascites also increased significantly. The in vitro experiment showed that ammonia leaked from the ischemic intestines, and secondarily, a large amount of ammonia was produced from intestinal putrefaction. The in vivo experiment revealed that the ammonia level in the blood could be used as a good early indicator of acute mesenteric ischemia.

Metaplastic shadow cells in rectal adenocarcinoma: report of a case with immunohistochemical study.

We report a case of adenocarcinoma of the rectum with foci of metaplastic shadow cells. The patient was a 65 year old man with anemia. Macroscopically the tumor was an ordinary rectal cancer. Microscopically, in addition to the features of moderately differentiated adenocarcinoma invading the subserosa, islands of shadow cells in tumor nests were detected in both primary and one of three pericolic metastatic lymph node lesions. Neoplastic glandular cells showed gradual transition to shadow cells. An antibody specific for high-molecular-weight cytokeratins reacted with the shadow cells and intermediate zone epithelial cells surrounding them, but no CEA, low-molecular-weight cytokeratins or cyclin D1 was detectable in them. Cytokeratin 14 was expressed only in the transitional zone epithelial cells. The intermediate zone epithelial cells were regarded as metaplastic squamous cells, from which the shadow cells were derived. The patient died of multiple liver metastases nine and a half months after surgery. To our knowledge, this is the first report of an immunohistochemical study of rectal adenocarcinoma containing shadow cells not only in the primary lesion but also in a metastatic lymph node.