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Biomedical subjects

T Tanizawa

Publications and source records attributed to T Tanizawa.

At least 55 records · Page 3Linked to original sources
PubMed1996

Bone particles disturb new bone formation on the interface of the titanium implant after reaming of the marrow cavity.

Histomorphometric studies were conducted in rats to determine whether bone particles would disturb new bone formation on the interface of titanium implants inserted after reaming of the marrow cavity. In eighty 10-week-old female Wistar rats, smooth-surfaced titanium alloy implants were inserted bilaterally into the marrow cavity after reaming in the distal femur. There were three experimental groups: in the irrigated femora, sterile saline was flushed through the medullary canal; in the particle femora, autologous bone particles were inserted into the intramedullary cavity; and in the reamed femora, the implant was inserted without procedures after reaming. The rats were sacrificed at one, two, four or eight weeks postoperatively, and Villanueva bone staining was applied for histomorphometric studies. The bone volume of new bone on the interface of the implant in the irrigated femora was greater than that in the particle or the reamed femora throughout the study period. The results suggest that clearance of bone particles by irrigation after reaming of the marrow cavity significantly facilitates new bone formation on the interface of implants by one week. The findings also suggest the potential clinical application of total canal irrigation prior to insertion of cementless femoral components as well as cemented prosthesis.

Absorptiometry, Photon↗
PubMed1996

Reactive lymphoid hyperplasia of the liver characterized by an angiofollicular pattern mimicking Castleman's disease.

A case of reactive lymphoid hyperplasia of the liver exhibiting a characteristic angiofollicular pattern is reported. A hepatic nodular lesion was discovered by abdominal echography during clinical follow-up of abnormal liver function tests. It was diagnosed as hepatocellular carcinoma because of its hypervascularity when observed by angiography, and surgically resected. Grossly, the lesion was well-demarcated and measured 2 cm in diameter. Microscopically, the nodule was composed of lymph follicles with germinal centers, and the hyalinized inter-follicular space contained abundant hyalinized vasculature and plasma cells. The surrounding liver tissue exhibited chronic inflammation with some peculiar angiofollicular structures mimicking Castleman's disease. An immunohistochemical study revealed that the angiofollicular structure had the same characteristics as a lymph follicle with a germinal center, and that the plasma cells proliferating in the inter-follicular space had polyclonal immunophenotypes. These histological and immunohistochemical findings indicated that the angiofollicular structure observed was a kind of reactive lymph follicle, and that this hepatic lesion was reactive lymphoid hyperplasia rather than Castleman's disease or an inflammatory pseudotumor.

Aged↗
PubMed1996

Decrease of mesangial matrix after immunosuppressive therapy in children with reversible membranoproliferative glomerulonephritis type I.

We followed the course of membranoproliferative glomerulonephritis (MPGN) type I after immunosuppressive therapy in 10 children. At diagnosis all patients had abnormal urinary findings. After a mean follow-up of 14 years all but one patient showed normal urinalysis and renal function. Glomerular morphometry revealed an increase in the ratio of mesangial matrix area to glomerular area (M/G%) in all patients. After immunosuppressive treatment, a second biopsy was performed, which showed a significantly decreased M/G% in 4 patients. In 3 of the remaining 6, the mean M/G% was significantly lower in a third biopsy when compared with the first. In addition, there was a negative correlation between M/G% and duration from onset disease to biopsy (r = -0.46, p <0.05). Fifteen biopsies (6 initial and 9 repeat biopsies) were examined for the staining of various extracellular matrices. In the initial biopsy type IV collagen, type V collagen and fibronectin were increased in expanded mesangial areas. Type III collagen was found segmentally in a few biopsies only. M/G% correlated with the grade of type IV collagen, type V collagen and fibronectin staining. These findings suggest that a reversible clinical course of MPGN type I in children is paralleled by a decrease of mesangial matrix expansion.

Adolescent↗
PubMed1996

[Successful induction of immune tolerance and novel hemostatic effects in a hemophilia A with high-responder inhibitor by regular infusions of factor VIII].

A hemophilia A patient with high responder inhibitor had been treated by (activated) prothrombin complex concentrates (A) PCC and activated factor VII until the occurrence of intracranial bleeding at the age of 6 years. Since the inhibitor titer was decreased less than 1 Bethesda Units/ml, high dose of factor VIII was given followed by the infusions of factor VIII concentrates (100 units/kg) three times a week. In spite of previous episodes of anamnestic responses by factor VIII products before, the inhibitor titer did not increase and disappeared completely 6 months after the FVIII infusion therapy. The specific anti-factor VIII IgG subclasses of the inhibitor were IgG2 and IgG4. The inhibitor recognized both light and heavy chains. He have no bleeding episode for 6 months since the beginning of the prophylactic with factor VIII concentrates.

Blood Coagulation Factors↗
PubMed1995

A histomorphometric study on effects of single and concurrent intermittent administration of human PTH (1-34) and bisphosphonate cimadronate on tibial metaphysis in ovariectomized rats.

This study compared the single administration of hPTH(1-34), bisphosphonate cimadronate (YM-175), and concurrent therapy of these two for restoration of lost bone mass in ovariectomized (OVX) rats. Animals were untreated for 4 weeks after surgery, and then injected s.c. with vehicle (OVX+V), hPTH(1-34) (30 micrograms/kg) (OVX+P), YM-175 (5 micrograms/kg) (OVX+Y), or a combination of these two (OVX+P+Y), 3 days a week, for 8 weeks, and sacrificed. Their proximal tibia were processed undecalcified for quantitative bone histomorphometry. Although OVX+Y showed a reduction of bone turnover compared to OVX+V, it failed to restore lost bone mass in OVX rats. In contrast, OVX+P exhibited a stimulation of bone formation and restored cancellous osteopenia due to OVX. OVX+P+Y also resulted a recovery of osteopenia, however, stimulation of bone formation by PTH was suppressed by YM-175.

Animals↗
PubMed1995

Discrepancy of response of hPTH administration and its withdrawal between trabecular and cortical bone sites in OVX rats.

We demonstrated the differences of response between trabecular and cortical bone sites in the rat induced by OVX and hPTH(1-34) administration [subcutaneous injection, 30 micrograms/kg, 3 times/week, for 12 weeks] and its withdrawal [for 8 weeks]. We observed that hPTH(1-34) administration in OVX rats partially prevented OVX-induced cancellous bone loss in the proximal tiabial metaphysis and added cortical bone in the tibial shaft. After cessation of hPTH treatment, bone loss was observed both in trabecular and cortical bone; however, it was more dramatic on endocortical surfaces.

Animals↗
PubMed1995

[Bone histomorphometric analysis in primary hyperparathyroidism].

In primary hyperparathyroidism, bone remodeling is increased due to an enhanced activation frequency which is caused by excessive PTH. In mild cases, eroded, osteoid and labeled surfaces are increased. But as bone balance per remodeling cycle in cancellous bone is zero or even slightly positive, bone volume and structure are relatively maintained. In advanced cases, bone resorption is predominant in the endosteal surface of cortical bone, resulting in progressive thinning and increased porosity, cancellisation. As far cancellous bone resorption depth is deepened to occur trabecular perforation associated with fibrous tissue replacement, osteitis fibrosa.

Bone Remodeling↗
PubMed1995

Silent and progressing accumulation of aluminum in bone without definite histological osteomalacic aspects in chronic hemodialysis patients.

The aluminum (Al) contents of the tap water and the dialysis fluid in our center had proven to be less than 10 micrograms/l during more than 10 years. We evaluated the Al content, stainable Al, and the histomorphometry of the bone biopsy specimens from the 23 chronic renal failure patients on dialysis. The plasma Ca, P, Mg, ALP, C-PTH, and Al levels except calcitonin (CT, r = 0.442, p < 0.05) had no significant relationship to the hemodialysis (HD) duration. Their bone histologies were classified as osteitis fibrosa (OF) in 9, mild type (MILD) in 11, mixed type (MIXED) in 2, and osteomalacia (OM) in 1. The stainable Al% on the trabecular bone surface showed a positive correlation with HD duration (r = 0.569, p < 0.001), with the bone Al content (r = 0.455, p < 0.05), and with the bone Al/Ca ratio (r = 0.668, p < 0.01), respectively. The bone Al, Ca and Mg content did not correlated with HD duration and with plasma Al levels, although the bone Al/Ca ratio showed a strong correlation with HD duration (r = 0.675, p < 0.01) and with plasma Al levels (r = 0.719, p < 0.001). In the histomorphometric parameters, plasma Al levels, stainable Al, bone Al content, as well as bone Al/Ca ratio had no significant correlation with the osteomalacic aspects. Thus, our observations revealed that the Al accumulation in the bones was latent and progressing without definite osteomalacic changes, even though the dialysate Al concentration was under the critical level. Other Al invasion roots besides dialysis fluid should be regarded, including oral intake of Al-containing phosphate binders or other gastrointestinal medicines, as well as food content.

Aluminum↗
PubMed1994

Bone mineral density and bone histomorphometric assessments of postpregnancy osteoporosis: a report of five patients.

Reports of five young women who developed vertebral fractures associated with pregnancy and lactation are presented (Fig. 1). Ages ranged from 24 to 37 (mean 30) years. All five patients have osteoporosis with two to nine vertebral fractures at presentation postpartum. Bone mineral density (BMD) was measured by single-photon absorptiometry, quantitative computer tomography, and dual-energy X-ray absorptiometry. BMD of the trabecular bone was less than normal values and it remained apparently low even several years after pregnancy. Histological findings of bone biopsy identified the bone loss with increasing bone resorption. Our present findings suggest that postpregnancy osteoporosis affects mainly the trabecular bone site, and the patients might have low peak bone mass and poor reversibility probably due to a low rate of remodeling.

Absorptiometry, Photon↗
PubMed1994

Immunolocalization of platelet-derived growth factor, transforming growth factor-beta, and fibronectin in acute megakaryoblastic leukemia manifesting tumor formation.

Acute megakaryoblastic leukemia (AMKL) manifesting myelofibrosis and tumor formation in the liver with marked increase of reticulin is described. The megakaryoblastic nature of the leukemic cells of the bone marrow and the hepatic tumor nodule was established by positive immunohistochemical stains for CD41a and CD41b on frozen tissue sections. Immunolocalization of the platelet-derived growth factor (PDGF) protein and transforming growth factor (TGF)-beta protein also was demonstrated in the leukemic cells of the bone marrow and the hepatic tumor. Further, the deposition of fibronectin that has been known as the ligand of CD41a molecule and collagen types I and IV were recognized in the extracellular matrix of the bone marrow and the hepatic tumor. These results suggest that specific expression of growth factor proteins by the leukemic cells may selectively regulate the fibrosis of the bone marrow as well as the tumor formation of AMKL. The expression of adhesion molecules and growth factor proteins by the leukemic cells and the deposition of extracellular matrix are discussed in relation to the myelofibrosis as well as the tumor-forming nature of AMKL.

Collagen↗
PubMed1994

p53 expression in myeloid cells of myelodysplastic syndromes. Association with evolution of overt leukemia.

To assess p53 expression in the hematopoietic cells of the bone marrow in premalignant as well as malignant conditions, we examined immunohistochemically bone marrow biopsies from patients with myelodysplastic syndromes (MDS, n = 51), acute myeloid leukemia (n = 42) and as a nonneoplastic condition, aplastic anemia (n = 20) and samples from individuals who had no hematological disorder (control, n = 12). Nuclear accumulation of p53 protein was found in seven of 51 patients with MDS (14%) and two of 42 acute myeloid leukemia patients (5%), whereas patients with aplastic anemia and control subjects were uniformly negative for p53 protein. In the bone marrow of patient with MDS, p53-positive cells constituted about 5 to 30% of the total bone marrow cells. Two-color immunohistochemical analysis revealed that the p53-positive cells were also positive for the myeloid cell marker. Half of the MDS cases that evolved to overt leukemia (seven of 14) exhibited positive p53 reaction in the bone marrow at the time of initial diagnosis. This frequency (50%) was significantly higher than that in de novo acute myeloid leukemia cases. All of the seven MDS cases that exhibited p53 expression at the time of initial diagnosis developed overt leukemia later, and p53 expression was maintained throughout the progression of MDS. The results suggest that p53 mutations that occur in the myeloid cells in MDS may confer a growth advantage to these cells resulting in the progression to overt leukemia. Thus, immunohistochemical examination for p53 is very useful for predicting the evolution to overt leukemia from MDS.

Acute Disease↗
PubMed1993

Maintenance of bone mass by physical exercise after discontinuation of intermittent hPTH(1-34) administration.

Human PTH(1-34) has been recognized for its marked anabolic effect on bone, but that effect has been reported to be lost after cessation of PTH treatment. The objective of this study was to determine the fate of hPTH-stimulated bone and whether this anabolic effect of PTH could be maintained by daily exercise. Eleven-week-old Sprague-Dawley rats were ovariectomized (OVX) and human PTH(1-34) (30 micrograms/kg) was injected subcutaneously three times per week for 12 weeks beginning one week after surgery. After the cessation of PTH treatment, treadmill exercises were performed for 8 weeks (15.7 m/min, 1 h/day, 5 days/week). The results of histomorphometric assessment in the proximal tibial metaphysis demonstrated that hPTH treatment partially prevented OVX-induced cancellous bone loss. Eight weeks following the cessation of PTH treatment, PTH-stimulated bone mass went back to the OVX control level. Daily exercise did maintain PTH-stimulated bone mass; however, this exercise did not increase the bone mass in PTH-untreated OVX rats.

Animals↗
PubMed1991

C3 deposition in IgA nephropathy in children and adolescents.

The aim of this study was to assess the significance of C3 deposition in IgA nephropathy in children and adolescents. One hundred and two patients aged 5-21 years (57 male and 45 female) were studied. The findings of C3 deposition were classified into 8 groups by immunofluorescent (IF) pattern and intensity as follows: group MC3+ (N = 12): mesangiocapillary pattern and 3+ in intensity; group MC2+ (N = 13): mesangiocapillary and 2+; group MC1+ (N = 4): mesangiocapillary and 1+; group M3+ (N = 11): mesangial and 3+; group M2+ (N = 24): mesangial and 2+; group M1+ (N = 18): mesangial 1+; group S (N = 12): only segmentally positive; and group N (N = 8): negative. Histological changes were scored semiquantitatively as an activity index (cellular proliferation, necrosis, interstitial cell infiltration, and cellular crescents) and a chronicity index (mesangial sclerosis, segmental and global glomerular sclerosis, fibrous crescents, adhesion and tubulo-interstitial change). IF findings were scored semiquantitatively and laboratory findings were also studied. The following results were obtained: 1) The scores of total activity index in MC groups were higher than in the M, S or N groups, and the greater the degree of C3 deposition, the higher the score; 2) Such result was not evident in the chronicity index; 3) High IF scores of IgG and IgM were found in the MC3+ and MC2+ groups; 4) Hematuria was more severe in MC3+ and MC2+ than in other groups, and proteinuria was more prominent in the MC than other groups. Thus the degree of C3 deposition was parallel with histological activity and urinary findings.

Adolescent↗
PubMed1991

C3 deposition in serially biopsied children with IgA nephropathy.

Twenty-five children with IgA nephropathy were studied by serial renal biopsy to investigate C3 deposition. The children were classified into three groups according to the immunofluorescent (IF) course of C3 deposition: group I (N = 9): unchanged or slightly decreased; group II (N = 4): changed to segmental deposition; and group III (N = 12): changed to negative deposition. Histological changes were scored semiquantitatively as an activity index (cellular proliferation, necrosis, interstitial cell infiltration and cellular crescents) and a chronicity index (mesangial sclerosis, segmental and global glomerular sclerosis, adhesion, fibrous crescents and tubulo-interstitial change). The IF findings were scored semiquantitatively and laboratory data were also studied. The following results were obtained: 1. Normal urinalysis was often observed in group III; 2. The IF scores of IgA and IgG were decreased at the second biopsy in all groups, most notably in group III; 3. The activity indices at second biopsies were decreased in all groups, most notably in groups II and III, consistently with our previous study which showed that C3 deposition increases in accordance with histological activity; 4. The chronicity index was unchanged in all groups and C3 deposition did not reflect histological chronicity. Thus, this study indicates that C3 deposition occurs as the disease progresses and reflects histological activity.

Adolescent↗
PubMed1991

[A study of urinary immunoglobulins and electrolyte excretion after lordosis].

We described a transient low or non-selective proteinuria after forced lordosis as a characteristic of orthostatic proteinuria and the heteroporous theory and sieving function theory which might explain the mechanism of orthostatic proteinuria. The angiogenic action of the renin-angiotensin system played an important part in these theories. Angiotensin II was recognized as the key regulator of renal sodium excretion, because it reduced the urinary Na/K ratio. Since the purpose of this study is to investigate the influence of the renin-angiotensin system on the mechanism of orthostatic proteinuria, proteins and electrolytes in the urine were examined before and after lordosis in 9 healthy children (Group A) and in 6 children with orthostatic proteinuria (Group B). The urinary ratio of protein/creatinine (P/cre) in Group B was already significantly higher than that in Group A before lordosis and significantly increased after lordosis, while P/cre in group A did not increase after lordosis. The urinary Na/K ratio (Na/K) in Group B was already significantly lower than that in Group A before lordosis, and after forced lordosis, Na/K in Group A decrease with no difference between both groups observed. It is suggested that a significant increase on P/cre after lordosis was obtained only in Group A, whereas in both groups the renal vein may be compressed by forced lordosis and as a result angiotensin II may be stimulated. There might be a difference of the responsibility to angiotensin II in glomerular mesangium contraction between both groups.

Adolescent↗
PubMed1989

Long-term follow-up of membranoproliferative glomerulonephritis type II and pregnancy: a case report.

A 24-year-old female was diagnosed as having membranoproliferative glomerulonephritis type II (or dense deposit disease), 11 years prior to becoming pregnant. The patient's first renal biopsy was performed 5 years after the onset of her renal symptoms. This biopsy was compared to a second renal biopsy taken just before the patient became pregnant. The second renal biopsy only showed a slight progression in the disease process. During the course of pregnancy, neither renal insufficiency nor hypertension were clinically evident. However, both an increase in proteinuria and a transient hypoalbuminemia were observed. The pregnancy, labor and delivery, and postpartum course for both the mother and child were without complications. Cases of membranoproliferative glomerulonephritis type I and pregnancy have been reported. However, to our knowledge, there are few reports documenting the outcome of pregnancy when a patient has membranoproliferative glomerulonephritis type II. We suggest that it is possible for a patient with membranoproliferative glomerulonephritis type II to have an uneventful pregnancy if she has neither hypertension nor renal insufficiency.

Adult↗