Biomedical subjects

Osamu Shimada

Publications and source records attributed to Osamu Shimada.

16 recordsLinked to original sources

PubMed2006

[Temporary inferior vena cava filter applied to 4 patients with urological disease].

A temporary inferior vena cava (IVC) filter was placed in 4 patients. Patient 1 had an advanced testicular germ cell tumor with IVC tumor thrombosis, patient 2 presented with a large adrenal tumor with IVC tumor thrombosis, patient 3 was found to have deep vein thrombosis following grade 3b renal injury, and patient 4 was suffering severe SLE with renal vein thrombosis. The temporary inferior vena cava filter prevented pulmonary thromboembolism in all cases, and no adverse reaction was observed. Temporary inferior vena cava filter is safe and useful to prevent pulmonary thromboembolism associated with urological disorders.

Adolescent↗

PubMed2006

Development of a portable instrument for the continuous analysis of volatile organic compounds (VOCs) and its application to environmental monitoring.

A small, time efficient and sensitive instrument for the continuous analysis of very volatile organic compounds (VOCs) with a boiling point lower than 100 degrees C in addition to the analysis of VOCs with a boiling point in the range of 100-150 degrees C was developed and applied to the measurement of VOCs in the course of university research and environmental monitoring. VOCs, such as n-hexane, acetone, ethyl acetate, alcohols, benzene, toluene and xylene, were continuously measured once every 30 min. The detection limits of hexane, ethyl acetate, benzene and toluene at a preconcentration time of 10 min were 0.41 microg/m(3) (0.12 ppb), 0.67 microg/m(3) (0.19 ppb), 0.22 microg/m(3) (0.07 ppb) and 0.22 microg/m(3) (0.06 ppb), respectively. The relative standard deviations of VOCs were less than 5%. The sensitivities of the present method VOCs were higher than those of the conventional method. The temporal changes in VOC concentrations in several laboratories and at a plant for the disposal of organic liquid wastes were measured, and the behavior of VOCs was analyzed. All the VOC concentrations, except that of ethyl acetate, determined using the portable instrument were slightly lower than those determined using a passive sampler. The portable instrument developed in the course of this study can be used for the risk assessment and management of chemicals.

Air Pollutants↗

PubMed2005

Immunohistochemical study of delta and mu opioid receptors on synaptic glomeruli with substance P-positive central terminals in chicken dorsal horn.

In an attempt to clarify the mechanism underlying the regulation of the release of substance P (SP) from the central axon terminals of the synaptic glomeruli in lamina II of the dorsal horn, we examined the expression patterns of delta and mu opioid receptors (DOR and MOR) in relation to those of enkephalin (ENK) and SP in the synaptic glomeruli. DOR, MOR, ENK and SP immunoreactivities in lamina II of the dorsal horn in the chicken were examined by confocal laser scanning and electron microscopies. DOR immunoreactivity was localized in both SP-positive central terminals and peripheral elements, while MOR immunoreactivity was only localized in the peripheral elements of the synaptic glomeruli. Both of the peripheral DOR- and MOR-immunoreactive elements were shown to be vesicle-containing dendrites by electron microscopy. Dual immunohistochemistry indicated that DOR, MOR and ENK immunoreactivities were located in distinct peripheral elements. On the basis of present results, the possible roles of DOR and MOR in the regulation of the release of SP from the central axon terminals in the synaptic glomeruli are discussed.

Animals↗

PubMed2005

Subsurface cisterna-lined axonal invaginations and double-walled vesicles at the axonal-myelin sheath interface.

The axonal-myelin sheath interface of vertebrate myelinated axons possesses special structural complexities, and there may be an intercellular macromolecular traffic transversing the periaxonal cleft that spans the internodal axon. By conventional electron microscopy and serial sectioning, we observed a category of double-walled vesicles at the axonal-myelin sheath interface, which often contained ribosome-like particles or endoplasmic reticulum. Some of them were demonstrated to continue with the subjacent axon with a thin stalk. In addition, we described a special category of axonal invaginations, probably mediated by subsurface cisternae. The functional implications of these specialized structures were discussed.

Action Potentials↗

PubMed2005

Cavernous nerve reconstruction during radical prostatectomy by sural nerve grafting: surgical technique in nerve harvesting and grafting.

The authors performed cavernous nerve reconstruction by nerve grafting in 22 patients (unilateral-16, bilateral-6) between August 2001 and June 2004. Harvesting of the sural nerve was unexpectedly more difficult than nerve grafting in the extremities or the head and neck, because a knee and lumbar bending position was impossible due to the pelvic surgical field. Suture of the grafted nerve on the distal side required great effort, because there was only sufficient space for one hand at the maximum in a deep region of the pelvic cavity, and the nerve ends easily become invisible by inflow of even a small amount of urine or blood. The mean time of the nerve harvesting and grafting was 1 hr 50 min for unilateral grafting and 2 hr 40 min for bilateral grafting. Recovery of erectile function was observed in about half the patients who had undergone surgery nearly 1 year before. Since harvesting of the sural nerve and nerve grafting were more difficult than expected, modification and improvement of many surgical elements, such as improvement of surgical devices and application of endoscopic techniques, are necessary.

Aged↗

PubMed2005

Colonic adenocarcinoma and stones in an Indiana pouch.

We report on a 63-year-old woman with adenocarcinoma and stones in an Indiana pouch. Adenocarcinoma of an Indiana pouch is extremely rare. To our knowledge, only four cases with adenocarcinoma in an Indiana pouch have been reported.

Adenocarcinoma↗

PubMed2005

Beyond the initial axon segment of the spinal motor axon: fasciculated microtubules and polyribosomal clusters.

Dense undercoating, microtubular fascicles and scattered polyribosomal clusters have until now been considered to be the three structural features of the initial segment, and were thought not to extend beyond the initial segment into the myelinated parts of the axon. The aim of the present study was to make clear whether there is a sudden change in morphology between the unmyelinated and myelinated part. We followed spinal motor axons from the initial segment to the first internode by conventional electron microscopy and serial sectioning, and found that the microtubular fascicles and polyribosomal clusters do exist in the internodal axoplasm. The fasciculated microtubules were observed mainly in the first paranode. The polyribosomal clusters were found along the course of the first internode at a random distance, however, they occurred mainly in the proximal part of the first internode. The proportion of sections in which ribosomes were found, i.e. the incidence of ribosomes, in the first 30-microm-long portion was 71 +/- 24% (mean +/- SD, n = 4), and significantly different from that in the second 30-microm-long portion (3.2 +/- 1.3%) (mean +/- SD, n = 4) (P < 0.005). The more distal part of the first internode was not investigated.

Animals↗

PubMed2005

An immunocytochemical study of calbindin-D28K in laminae I and II of the dorsal horn and spinal ganglia in the chicken with special reference to the relation to substance P-containing primary afferent neurons.

The localization of calbindin-D28K (CB) was studied immunocytochemically in laminae I and II of the dorsal horn and in spinal ganglia in the chicken, and compared with the distribution of substance P (SP) using double immunolabeling. At the light microscopic level, CB immunoreactivity was observed most intensely in the lamina II using the avidin-biotinylated peroxidase complex (ABC) and immunofluorescence methods. At the electron microscopic level using the ABC method, CB immunoreactivity was observed in the following three neuronal elements: 1) the scalloped central terminal with many dense-cored vesicles (DCVs) in the synaptic glomerulus; 2) some vesicle-containing dendrites (VCDs) inside or outside the synaptic glomerulus; and 3) some axon terminals outside the synaptic glomerulus. The CB-immunoreactive (IR) VCDs in the synaptic glomerulus often formed reciprocal synapses with the central terminal. Strong immunoreactivity was observed at the postsynaptic membrane of CB-IR elements. Double immunofluorescence and immunolabeling methods at the electron microscopic level showed that CB and SP colocalized in the scalloped central terminal with DCVs of the synaptic glomerulus. Almost all SP-IR neurons in the spinal ganglion revealed the coexistence of CB in serial sections in the chicken. In light of previous biochemical and physiological reports, our findings suggest that CB - coexisting with SP - plays an important role in the control of pain transmission through its strong Ca(2+)-buffering action in the chicken.

Animals↗

PubMed2004

Mitochondrial accumulation in the distal part of the initial segment of chicken spinal motoneurons.

The axonal initial segment is the initiation site of action potentials and is characterized morphologically by a dense undercoating and fascicles of microtubules connected by cross-bridges. In order to analyze subcellular structures in the initial segment, we made serial transverse sections of initial segments of identified chicken motoneurons by retrograde transport of horseradish peroxidase (HRP) injected into the muscle. The mean (+/-SD) length of the initial segment was 28.1+/-2.3 microm (n=6). Mitochondria accumulated in the distal part of the initial segment, which was 1.4-6.9 microm in length (5-23% of the total length of the initial segment). In the transverse section of the distal part, mitochondrial density was 15.8+/-6.2% (n=5), while in the middle and proximal parts it was 6.1+/-1.6% and 5.6+/-1.4%, respectively. Mitochondrial accumulation was observed in common in phasic and tonic motoneurons in the chicken, and also observed in the distal part of the initial segment of the large ventral horn neurons of the chicken without HRP injection. These findings suggest that accumulated mitochondria play an important role in maintaining the physiological function of the distal part of the motoneuron initial segment.

Animals↗

PubMed2004

The binding of VIP36 and alpha-amylase in the secretory vesicles via high-mannose type glycans.

Vesicular integral protein of 36 kDa (VIP36) is an intracellular lectin recognizing high-mannose type glycans and is highly expressed in salivary glands, especially the parotid gland, which secretes alpha-amylase in large quantities. Here immunoelectron microscopy demonstrated that VIP36 was primarily localized to secretory vesicles in the glandula parotis of the rat, where alpha-amylase also resided. A secretory vesicle fraction, prepared by Percoll density gradient centrifugation, contained both VIP36 and alpha-amylase. Moreover, alpha-amylase that was localized to these secretory vesicles contained high-mannose type glycans. In addition, VIP36 coprecipitated with alpha-amylase in an endo H treatment-sensitive manner. These results suggest that VIP36 is involved in the secretion of alpha-amylase in the rat parotid gland.

Animals↗

PubMed2004

[Three dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer under field adjustment with implanted gold markers: early clinical outcome].

Three dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer under field adjustment with gold marker implantation was performed according to the treatment strategy based on the clinical risk factors to the patients who chose external beam radiotherapy. The treatment strategy contains indications for laparoscopic staging lymphadenectomy and neoadjuvant combined androgen blockade (CAB). This protocol was applied to 19 patients at Kagawa University Hospital from July 2001 to December 2003. The patients were divided into high-risk group (n=14): T3-4N0M0 or PSA > or = 20 ng/ml or Gleason sum > or = 8 or suspicious node, and low-risk group (n=5): T1c-2bN0M0 and PSA < 20 ng/ml and Gleason sum < or = 7 and no suspicious nodes. Basically, high-risk patients underwent laparoscopic staging lymphadenectomy prior to radiotherapy. One of the 14 patients had a positive node and underwent endocrine therapy. The high-risk group received neoadjuvant CAB for 3 to 4 months, followed by gold marker implantation. One patient chose endocrine therapy at this point. Low-risk patients underwent marker implantation without endocrine therapy. Every patient successfully completed planned irradiation. The changes of prostate volume and serum PSA after neoadjuvant CAB were significant [28.7 ml to 15.7 ml (p=0.004) and 53.9 ng/ml to 1.4 ng/ml (p=0.023), respectively]. Only one patient in the high-risk group had biochemical failure. No grade 3 or 4 adverse events occurred in NCI-CTC grading. The analysis of gravity center migration of the implanted gold markers in the first 8 patients showed that the planned safety margin might not be wide enough to avoid neighboring organ irradiation. These results suggested that 3D-CRT under field adjustment with implanted gold markers contributes to both higher efficacy and lower morbidity.

Aged↗

PubMed2003

Localization of VIP36 in the post-Golgi secretory pathway also of rat parotid acinar cells.

VIP36 (36-kD vesicular integral membrane protein), originally purified from Madin-Darby canine kidney (MDCK) epithelial cells, belongs to a family of animal lectins and may act as a cargo receptor. To understand its role in secretory processes, we performed morphological analysis of the rat parotid gland. Immunoelectron microscopy provided evidence that endogenous VIP36 is localized in the trans-Golgi network, on immature granules, and on mature secretory granules in acinar cells. Double-staining immunofluorescence experiments confirmed that VIP36 and amylase co-localized in the apical regions of the acinar cells. This is the first study to demonstrate that endogenous VIP36 is involved in the post-Golgi secretory pathway, suggesting that VIP36 plays a role in trafficking and sorting of secretory and/or membrane proteins during granule formation.

Animals↗

PubMed2003

Clusters of VIP-36-positive vesicles between endoplasmic reticulum and Golgi apparatus in GH3 cells.

The vesicular integral membrane protein VIP36 belongs to the family of animal lectins and may act as a cargo receptor trafficking certain glycoproteins in the secretory pathway. Immunoelectron microscopy of GH3 cells provided evidence that endogenous VIP36 is localized mainly in 70-100-nm-diameter uncoated transport vesicles between the exit site on the ER and the neighboring cis-Golgi cisterna. The thyrotrophin-releasing hormone (TRH) stimulation and treatment with actin filament-perturbing agents, cytochalasin D or B or latrunculin-B, caused marked aggregation of the VIP36-positive vesicles and the appearance of a VIP36-positive clustering structure located near the cis-Golgi cisterna. The size of this structure, which comprised conspicuous clusters of VIP36, depended on the TRH concentration. Confocal laser scanning microscopy confirmed the electron microscopically demonstrated distribution and redistribution of VIP36 in these cells. Furthermore, VIP36 colocalized with filamentous actin in the paranuclear Golgi area and its vicinity. This is the first study to show the ultrastructural distribution of VIP36 in the early secretory pathway in GH3 cells. It suggests that actin filaments are involved in glycoprotein transport between the ER and cis-Golgi cisterna by using the lectin VIP36.

Animals↗

PubMed2002

Involvement of VIP36 in intracellular transport and secretion of glycoproteins in polarized Madin-Darby canine kidney (MDCK) cells.

VIP36, an intracellular lectin that recognizes high mannose-type glycans (Hara-Kuge, S., Ohkura, T., Seko, A., and Yamashita, K. (1999) Glycobiology 9, 833-839), was shown to localize not only to the early secretory pathway but also to the plasma membrane of Madin-Darby canine kidney (MDCK) cells. In the plasma membrane, VIP36 exhibited an apical-predominant distribution, the apical/basolateral ratio being approximately 2. Like VIP36, plasma membrane glycoproteins recognized by VIP36 were found in the apical and basolateral membranes in the ratio of approximately 2 to 1. In addition, secretory glycoproteins recognized by VIP36 were secreted approximately 2-fold more efficiently from the apical membrane than from the basolateral membrane. Thus, the apical/basolateral ratio of the transport of VIP36-recognized glycoproteins was correlated with that of VIP36 in MDCK cells. Upon overproduction of VIP36 in MDCK cells, the apical/basolateral ratios of both VIP36 and VIP36-recognized glycoproteins were changed from approximately 2 to approximately 4, and the secretion of VIP36-recognized glycoproteins was greatly stimulated. In contrast to the overproduction of VIP36, that of a mutant version of VIP36, which has no lectin activity, was of no effect on the distribution of glycoproteins to apical and basolateral membranes and inhibited the secretion of VIP36-recognized glycoproteins. Furthermore, the overproduction of VIP36 greatly stimulated the secretion of a major apical secretory glycoprotein of MDCK cells, clusterin, which was found to carry at least one high mannose-type glycan and to be recognized by VIP36. In contrast to the secretion of clusterin, that of a non-glycosylated apical-secretion protein, galectin-3, was not stimulated through the overproduction of VIP36. These results indicated that VIP36 was involved in the transport and sorting of glycoproteins carrying high mannose-type glycan(s).

Animals↗

PubMed2002

Retroperitoneoscopic partial nephrectomy using microwave coagulation for small renal tumors.

OBJECTIVES: The outcome of laparoscopic partial nephrectomy using a microwave tissue coagulator for treatment of small renal tumors was studied. PATIENTS AND METHODS: From June 1999 to May 2001, eight patients with small renal tumors of less than 5.0cm in diameter (1.0-5.0cm, T1N0M0) underwent retroperitoneoscopic partial nephrectomy. To control bleeding during the partial nephrectomy, the renal parenchyma around the tumor was coagulated using a microwave tissue coagulator with a needle of 1.5cm length. The tumor was circumscribed within the coagulated area with 8-13 punctures of the coagulation needle, and partial nephrectomy was performed using scissors and bipolar forceps. RESULTS: All eight patients successfully underwent the procedure retroperitoneoscopically. The average operative time was 295 minutes and the average blood loss was 129ml. Three patients showed urine leakage from the renal calyces, which was controlled by suturing retroperitoneoscopically. In two patients, the surgical margin was revealed to be positive for renal cell carcinoma by frozen section pathology and additional resection was performed in these individuals. The patients were discharged from the hospital with almost full convalescence on day 10 on average. Within the mean follow-up period of 10.4 months, no recurrence was found when examined with computer tomography (CT) using contrast media. As a complication, one patient experienced a decrease in function of the operated kidney caused by unknown reason. CONCLUSION: Retroperitoneal partial nephrectomy using a microwave tissue coagulator is useful for treatment of small renal tumors located at the peripheral area of the kidney. Bleeding from the renal parenchymal incision site is well controlled without occlusion of the renal artery with additional use of a bipolar coagulator, when necessary. Further experience and long-term follow-up are mandatory however, to establish the usefulness of this technique.

Adult↗

PubMed2002

[The experience of laparoscopic radical nephrectomy for renal tumors].

We evaluate the safety and feasibility of laparoscopic radical nephrectomy for renal tumors. Between September 1993 and October 2001, 18 patients with renal tumors underwent laparoscopic radical nephrectomy. The mean patient age was 57.1 years ranging from 36 to 78. Clinical stage was T1N0 in all patients. The mean tumor diameter was 4.0 cm ranging from 1.8 to 7.0. Laparoscopic radical nephrectomy was performed by using the transperitoneal anterior approach on 11 patients and retroperitoneal approach on 7 patients. The specimen was removed through an extended stab wound after blunt segmentation of renal parenchyma in a specimen bag (LapSac). The mean operative time was 405 (270-550) and 453 (325-635) min for the transperitoneal approach and retroperitoneal approach respectively, and the mean blood loss was 281 (52-700) and 223 (10-850) ml, respectively. There was an intraoperative complication of minor splenic injury in 2 patients receiving the transperitoneal approach, which was conservatively managed. Histopathology revealed renal cell carcinoma in 17 patients and renal oncocytoma in one patient. There was no recurrence with a mean follow-up of 28.9 months. Compared with 13 patients who underwent open radical nephrectomy during the same period, laparoscopic nephrectomy has a longer operative time (424 versus 214 min, p < 0.001), equal blood loss (259 versus 210 ml, p = 0.59), quicker resumption of ambulation (1.8 versus 2.5 days, p = 0.016) and food intake (1.4 versus 2.2 days, p = 0.003), shorter postoperative hospital stay (10.9 versus 18 days, p = 0.0016), and a tendency of less frequent analgesic requirements (1.9 versus 4.7 times, p = 0.09). Laparoscopic radical nephrectomy is a safe and useful surgery for renal tumors providing minimal invasiveness.

Adult↗