Three-dimensional computer modeling for pattern formation on the surface of an expanding polymer gel.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to N Suematsu.
Explore the source record for details and available documents.
The prostate gland develops from the fetal urogenital sinus at the base of the urinary bladder. It finally differentiates into three lobes; ventral, lateral and dorsal lobes of the prostate. In spite of their common developmental origin and similar glandular structure, these lobes show the different biochemical characteristics, for example, in the proteins they secrete. In the present study, we investigate the involvement of the epithelial-mesenchymal interaction in the lobe-specific differentiation of the prostatic epithelium by means of epithelial-mesenchymal recombination experiments. We have used a prostatic steroid-binding protein (PSBP) as a specific differentiation marker for the ventral prostate. PSBP is a tetramer which consists of 2 sub-units, one containing the polypeptides C1 and C3 and the other containing the polypeptides C2 and C3. Northern analysis with a complementary DNA probe encoding C1 peptide (PSBP-C1) revealed that the mRNAs were detected exclusively in the ventral prostate but not in the dorsal prostate or in other organs such as urinary bladder and kidney. In situ hybridization with a complementary (anti-sense) RNA probe demonstrated that the transcripts were found only in the epithelium, not in the mesenchyme of the ventral prostate. In situ hybridization also showed that, in normal development, the mRNAs for PSBP-C1 in the ventral epithelium were first detectable at day 14 after birth, coinciding with the onset of its cytodifferentiation, and that they reached mature levels by day 21. We then carried out tissue-recombination experiments to examine whether the transcription of the PSBP-C1 gene in the epithelium is affected by the surrounding mesenchyme. Fetal urogenital sinuses were subdivided into ventral and dorsal halves. Following collagenase treatment, both halves were separated into their epithelial and mesenchymal compartments. Homotypic (ventral epithelium plus ventral mesenchyme [Ev/Mv] and dorsal epithelium plus dorsal mesenchyme [Ed/Md]) and heterotypic (ventral epithelium plus dorsal mesenchyme [Ev/Md] and dorsal epithelium plus ventral mesenchyme [Ed/Mv]) recombinations were carried out. After 4-5 weeks of growth in male host, the glandular structures characteristic for prostate glands were formed in all explants. However, in situ hybridization revealed the transcripts of the PSBP-C1 gene only in the epithelium associated with the ventral mesenchyme (Ev/Mv and Ed/Mv).(ABSTRACT TRUNCATED AT 400 WORDS)
Explore the source record for details and available documents.
A large gap in peripheral nerve will not allow effective regeneration unless a grafting conduit is used to bridge the defect. Conventionally, nerve tissue has been used as such a conduit in nerve reconstruction; however, results from techniques using these grafts are often unsatisfactory. A number of recent investigations have indicated that nerve fibers will regenerate through a non-neural tube. The purpose of this review is: 1) to provide an overview of the various tubulation techniques previously reported for peripheral nerve gap repair; 2) to investigate new possibilities for enhancing the regenerative capacity of nerves following these tubulation techniques by drawing from technical innovations in microsurgery and recent progress in immunology and neurobiology. The interposed graft thus may perform a more positive role, not merely as a pathway for deregenerating axons, but as a source for neuronotrophic factors and neurite-promoting factors, which would nurture and guide the neurons and axons. Such modifications in graft materials may lead to clinical applications of tubulation of nerve defects that would result in an improvement in clinical results.
A case of brachial plexus injury caused by electric current is reported. A 14-year-old boy touched a bare electric cord with his right fifth finger. The electric current ran from the finger through the extremity to the neck. Then it caused brachial plexus palsy gradually. The clinical course and the electrophysiological examination revealed that the affected nerve fibers were in a state of neurapraxia.
A 35-year-old unmarried woman was admitted to our hospital because of right pneumothorax. Pulmonary lymphangiomyomatosis was suspected from CT and transbronchial lung biopsy findings. The diagnosis was confirmed histologically by open lung biopsy. As her biopsy specimen showed positive findings for both estrogen and progesterone receptor, tamoxifen administration was started. The CT revealed multiple cystic lesions (5-10 mm in diameter) but otherwise normal vascular structures and normal lung density. The plain chest radiograph showed no abnormalities. CT is very useful for the early detection of pulmonary lymphangiomyomatosis.
Ten millimeter gaps in sciatic nerves of rats were repaired by vein grafting (n = 30) and by nerve grafting (n = 30). Electrophysiologic evaluation demonstrated that the nerve-graft group had a significantly higher percentage of re-innervation and shorter delay of terminal latency in myoelectrical response evoked by electrical stimulation of the sciatic nerve, compared with the vein-graft group at two and three months. But there were no differences between the two grafted groups after six months. In both grafted groups, the numbers of myelinated nerve fibers increased substantially over time, although the vein-grafted segments had smaller numbers of fibers than the nerve-grafted segments at both three and 12 months. Microangiograms also demonstrated different patterns of revascularization between the two groups. Results suggest that, although autologous vein grafting requires a longer period of time for nerve regeneration, compared with autologous nerve grafting, its ability to repair nerve is considerable.
Explore the source record for details and available documents.
A 54-year-old man, who had the history of a blood transfusion 29 years ago, was admitted to our hospital because of dyspnea and abdominal fullness. Physical examination revealed jaundice and massive ascites and laboratory data suggested liver cirrhosis. The high level of AFP and a CT scan indicated the association of hepatocellular carcinoma and its metastasis to the right adrenal gland. On the 21st hospital day, he suddenly complained of severe pain in the right upper quadrant and the right flank, and fell into hemorrhagic shock. Blood transfusion was given, but he died on the 24th hospital day. Autopsy revealed liver cirrhosis, accompanied by hepatocellular carcinoma with the metastasis to the right adrenal gland and multiple pulmonary tumor thrombi. Massive hemorrhaging due to rupture of the right adrenal metastasis was seen in the retroperitoneal space.
The clinical and radiologic course was reviewed in seven patients treated with an iliac osteocutaneous free flap (iliac flap) for treatment of large bone defects in the tibia and first metacarpal bone and overlying skin. Application of the iliac flap was followed by free bone grafting in four patients and aesthetic surgery in four patients. All patients obtained solid bony union and good skin coverage; none had complaints upon walking. An iliac flap was useful as a salvage procedure for the treatment of massive defect of bone and skin in extremities, especially in the lower one-third of the lower leg. Transient osteoporosis occurred before osteosclerosis and bony union. Bone remodeling with change in the trabecular pattern preceded transformation from cancellous to cortical bone.
Epithelio-mesenchymal recombination experiments revealed that urogenital-sinus mesenchyme of normal rat fetuses failed to induce androgen-receptors in sinus epithelium of androgen insensitive Tfm (testicular ferminization) mouse fetuses. Nevertheless, the mesenchyme can induce the morphogenesis of prostate-like glands in the androgen-receptor-deficient epithelium.
Free vascularised bone grafting was performed on six patients with large segmental bone defects following trauma, osteo-cutaneous defects and large bony defects following tumour resection. A free vascularised fibular graft was performed in five patients and a free iliac osteo-cutaneous flap was performed in one patient. In all patients, bony fusion was achieved by two to three months, without infection or recurrence of bone tumour. The donor site deficit was minimal.
Trigger wrist is a rare condition unlike the trigger finger of the metacarpophalangeal joint. This report describes a case of trigger wrist secondary to a giant cell tumour of the flexor tendon sheath. No previous reports are available in the medical literature.
An unusual case of classic thymic granuloma is reported. A 16-year-old boy presented with a huge mediastinal mass and the superior vena caval syndrome. Irradiation and combination chemotherapy induced complete remission, despite several episodes of lymph node recurrence. Examination of the first biopsy specimen was considered to indicate a histiocytic tumor or malignant form of eosinophilic granuloma, because of the diffuse proliferation of histiocytes and marked infiltration of eosinophils. Late involvement in the lymph node appeared to have the same histologic characteristics as the mediastinal tumor. Immunohistochemically, the proliferating histiocytes were stained with anti-S100 protein IgG but not with anti-lysozyme or anti-NCA (nonspecific cross-reacting antigen with carcinoembryonic antigen) antibody. These characteristics were similar to those of interdigitating cells in the lymph nodes, thymus, and other lymphoid tissues. The relationship of this case to mediastinal Hodgkin's disease or proliferative disorders of histiocytes is discussed.
To elucidate the influence of the alpha1-antichymotrypsin (ACT) polymorphism on Alzheimer-type neuropathological changes and the development of sporadic Alzheimer's disease (AD), we studied the relationship between the ACT polymorphism and the severity of Alzheimer-type neuropathological changes in the brains from AD patients and nondemented subjects. There was no association of the ACT polymorphism with Alzheimer-type neuropathological changes in AD or nondemented individuals. ACT polymorphism was not associated with the development of AD. These results remained nonsignificant when the ACT genotype groups were divided into subgroups according to the apolipoprotein E (ApoE) epsiolon4 status. Our study shows that the ACT polymorphism has no effect on Alzheimer-type neuropathological changes or the development of AD, either alone or in combination with ApoE epsiolon4.
A subset of senile dementia, 'senile dementia (SD) of the neurofibrillary tangle (NFT) type' (SD-NFT), is characterized by numerous NFTs in the hippocampal region and absence or scarcity of senile plaques throughout the brain. To elucidate the pathogenesis of SD-NFT in comparison with Alzheimer's disease (AD), we investigated the hippocampal lesions and analyzed the tau gene. The hippocampal regions from 5 patients with SD-NFT were neuropathologically evaluated in comparison with AD and nondemented control subjects. The tau gene was analyzed in 3 patients with SD-NFT. The densities of NFTs in the CA1/subiculum and entorhinal cortex of SD-NFT were significantly higher than those in AD. However, hippocampal atrophy, neuronal and synaptic loss, and astrocytic and microglial proliferation in SD-NFT were significantly mild compared with AD. There was no significant difference between SD-NFT and AD in the immunoreactivities of NFTs with different anti-tau antibodies. No mutation was found in the tau gene from the SD-NFT patients. Our results indicate that the neurodegenerative process with NFT formation of the hippocampal region in SD-NFT would be different from that in AD.
In the neuropathological investigations of 32 demented patients with severe cerebral amyloid angiopathy (CAA), we found an unusual case, a 90-year-old woman, presenting with the pathology of atypical Alzheimer's disease (AD). The case showed severe plaque-like angiopathy, in which all the senile plaques except for some diffuse plaques were formed around amyloid beta (/A4) protein-laden vessels. Analysis of the amyloid beta protein precursor gene from the patient revealed no mutation. Our results have indicated that, among demented patients with severe CAA, there is the vascular variant of AD characterized by severe plaque-like beta protein angiopathy.