Biomedical subjects

H Kitamura

Publications and source records attributed to H Kitamura.

At least 37 records · Page 2Linked to original sources

PubMed2001

Induction of transplantation tolerance with a short course of tacrolimus (FK506): I. Rapid and stable tolerance to two-haplotype fully mhc-mismatched kidney allografts in miniature swine.

BACKGROUND: Inbred miniature swine provide a large animal model in which the effects of selective major histocompatibility complex (MHC) matching can be reproducibly studied. We have previously demonstrated that although a 12-day course of cyclosporine uniformly induces tolerance to class I-mismatched renal allografts, it does not induce tolerance across full MHC barriers. In this study, we assessed whether and at what dose tacrolimus might permit allografts to induce tolerance across different MHC barriers. METHODS: Recipients of MHC disparate renal allografts were treated with a 12-day course of tacrolimus by continuous intravenous infusion. Groups were divided as follows: (1) class I-mismatched kidneys with 0.3 mg/kg/day tacrolimus (n=3); (2) fully MHC-mismatched kidneys with 0.3 mg/kg/day tacrolimus (n=2); and (3) fully MHC-mismatched kidneys with 0.12-0.16 mg/kg/day tacrolimus (n=4). RESULTS: In groups 1 and 2, recipients with tacrolimus levels of 45-80 ng/ml accepted renal allografts long-term with stable renal function. Donor-specific hyporesponsiveness was demonstrated by cell-mediated lymphocytotoxicity and mixed lymphocyte response, and subsequent donor-matched grafts were also accepted, without further immunosuppression (n=4), confirming systemic tolerance. In group 3, recipients that achieved tacrolimus levels of 35 ng/ml (n=2) accepted their grafts without chronic changes, whereas recipients with levels of 20-26 ng/ml (n=2) developed chronic allograft glomerulopathy, suggesting 35 ng/ml as the threshold blood level for tolerance induction. In vitro assays demonstrated that peripheral blood lymphocytes from tolerant animals produced inhibitory cytokines, suggesting the involvement of regulatory mechanisms. CONCLUSIONS: To our knowledge, this study represents the first demonstration of the induction of transplant tolerance across a two-haplotype full MHC barrier with a short course of immunosuppression in a large animal model. These studies may also have clinical applicability, because the time course required to induce tolerance was sufficiently short that the high drug levels required might be expected to be tolerated clinically with only transient toxicity.

Animals↗

PubMed2001

AG-041R, a novel indoline-2-one derivative, induces systemic cartilage hyperplasia in rats.

AG-041R (3R-1-(2,2-diethoxyethyl)-3-((4 methylphenyl)aminocarbonylmethyl)-3-((4-methylphenyl) ureido)-indoline-2-one) is a novel small compound synthesized as a cholecystokinin-2 (CCK(2))/gastrin receptor antagonist. In the course of the development of this compound, we discovered unexpectedly that oral administration of a high dose for 4 weeks markedly induced systemic cartilage hyperplasia. This change was histologically observed in the auricles, the trachea, the marginal region of the femoral condyle, the xiphoid process and intervertebral disks in rats. Daily intraarticular injections of AG-041R into rat knee joints for 3 weeks also caused cartilage hyperplasia in the marginal region of the femoral condyle, but no hyperplasia was observed in any other cartilage. We have confirmed that chondrogenic activity of AG-041R is an intrinsic property of the compound, and is not due to its CCK(2)/gastrin receptor antagonistic actions. These results indicate that AG-041R is a novel stimulator of chondrogenesis, and can be expected to be a potent therapeutic agent for cartilage disorders.

Administration, Oral↗

PubMed2001

Occurrence of gangliosides in the common squid and pacific octopus among protostomia.

Acidic lipids from tissues of the common squid Todarodes pacificus and the pacific octopus Octopus vulgaris were characterized. Hepatopancreatic tissues of both animals had complex compositions of resorcinol-positive acidic lipids, many of which became reactive with cholera toxin B subunit and anti-G(M1) antibody after in situ treatment with sialidase on TLC. One of the major acidic lipids in squid tissue was isolated and examined for its structure. This acidic lipid was identified to be the ganglioside G(D1a) based upon the susceptibility to sialidases of different substrate specificity, characterization of reaction products, and electrospray ionization-mass spectrometry of the lipid. Hepatopancreatic tissues of squid and octopus also contained acidic lipids that reacted with A2B5, a monoclonal antibody specific to c-series gangliosides. Cerebral ganglia of both animals expressed resorcinol-positive acidic lipids, though their compositional patterns differed from the hepatopancreatic tissues. N-Acetylneuraminic acid was identified as the main species in lipid-bound sialic acid in both tissues. The contents of lipid-bound sialic acid in cerebral ganglia were significantly lower than those of hepatopancreatic tissues in both animals. The present study presents the first evidence for the occurrence of gangliosides in protostomia.

Animals↗

PubMed2001

Determination of the levels of novel 31-amino acid endothelins and endothelins in human lungs.

An effective method for determination of the levels of newly discovered 31-amino acid endothelins [ETs(1-31)] as well as big ETs and 21-amino acid ETs [ETs(1-21)], in human lungs has been developed. About 85% of ETs in human lung homogenates were recovered on acid extraction 8 times. Most of the published protocols for the determination of tissue ETs involve a reverse-phase minicolumn to separate proteins from peptides, after which the levels of ETs are directly determined by enzyme immunoassay. The levels determined, however, include fairly high amounts of non-bioactive ET metabolites in tissues and the data reported are diverse. We established an effective methods for the extraction and the separation of nine different muscle constricting ETs from their metabolites on a reverse-phase C18 column. Using this protocol, the levels of ETs in human lungs were determined by means of a sandwich-enzyme immunoassay specific for each ET derivative. The levels of ET-2(1-21) were the highest among those of ETs, and the levels of ETs(1-31) were in a similar range to those of big ETs but were lower than those of ETs(1-21). This method can be utilized to assess the pathophysiological roles of ETs(1-31) in various human organs.

Chromatography, High Pressure Liquid↗

PubMed2001

Posttransplantation lymphoproliferative disease in miniature swine after allogeneic hematopoietic cell transplantation: similarity to human PTLD and association with a porcine gammaherpesvirus.

Posttransplantation lymphoproliferative disease (PTLD) is a major complication of current clinical transplantation regimens. The lack of a reproducible large-animal model of PTLD has limited progress in understanding the pathogenesis of and in developing therapy for this clinically important disease. This study found a high incidence of PTLD in miniature swine undergoing allogeneic hematopoietic stem cell transplantation and characterized this disease in swine. Two days before allogeneic peripheral blood stem cell transplantation, miniature swine were conditioned with thymic irradiation and in vivo T-cell depletion. Animals received cyclosporine daily beginning 1 day before transplantation and continuing for 30 to 60 days. Flow cytometry and histologic examination were performed to determine the cell type involved in lymphoproliferation. Polymerase chain reaction was developed to detect and determine the level of porcine gammaherpesvirus in involved lymph node tissue. PTLD in swine is morphologically and histologically similar to that observed in human allograft recipients. Nine of 21 animals developed a B-cell lymphoproliferation involving peripheral blood (9 of 9), tonsils, and lymph nodes (7 of 9) from 21 to 48 days after transplantation. Six of 9 animals died of PTLD and 3 of 9 recovered after reduction of immunosuppression. A novel porcine gammaherpesvirus was identified in involved tissues. Miniature swine provide a genetically defined large-animal model of PTLD with many characteristics similar to human PTLD. The availability of this reproducible large-animal model of PTLD may facilitate the development and testing of diagnostic and therapeutic approaches for prevention or treatment of PTLD in the clinical setting.

Amino Acid Sequence↗

PubMed2001

Analysis of gap junction formation in rat hepatocytes by intravenous injection of an anti-connexin32 monoclonal antibody (HAM8).

HAM8 monoclonal antibody was used to examine the mechanism of connexin32 (Cx32) formation in the rat model in vivo by immunofluorescence and immunoelectron microscopy. After a single intravenous injection of HAM8 IgG, a number of HAM8 signals were observed at the sinusoidal face, between adjacent hepatocytes as well as in the cytoplasm stained with only 2nd fluorescent antibody. Moreover, the in vivo localization of the HAM8 antigen appeared to change with time. At 5 min after the antibody injection, Cx32 signals from liver sections were clearly detected at the sinusoidal face. Fifteen minutes later, numerous linear and dotted fluorescent signals were observed between hepatocytes; in addition, much punctate staining was found at the sinusoidal face and in hepatocytes. These findings were identified by immunoelectron microscopy. Interestingly, 1 hr later, much punctate staining considered to be similar to those seen in the normal rat liver tissues was observed between adjacent hepatocytes, suggesting that a great deal of Cx32 combined with HAM8 have been assembled into identifiable gap junction plaques. Five hours later, intercellular and intracellular Cx32 signals were infrequently detected. When staining was performed with HAM8 and 2nd antibody, however, numerous Cx32 signals were again observed between neighboring hepatocytes, as punctate staining appearing in a pattern approximately the same as that seen in the normal liver tissue. Based on these results, we assumed that a precursor gap was present during Cx32 formation, and discussed the pathways of Cx32 formation and the degradation of Cx32 as well as that of HAM8.

Animals↗

PubMed2001

Increased secretion of tumour necrosis factor and interleukin 6 from isolated, perfused liver of rats after partial hepatectomy.

The present study explored the changes in hepatic secretion of tumour necrosis factor (TNF) and interleukin 6 (IL-6) during the regenerative process of the liver, focusing on the role of Kupffer cells. The secretions of TNF and IL-6 from the perfused rat liver were increased after 67% partial hepatectomy, reaching a maximum at 48 h. The response of cytokine secretion induced by lipopolysaccharide (LPS: 1 microgram/ml) was also potentiated in regenerating liver. The secretion of TNF, but not that of IL-6, induced by LPS was almost totally suppressed by pretreatment of rats with gadolinium chloride, which depletes Kupffer cells. These results indicate that hepatic secretions of TNF and IL-6 are increased during the regenerative process of the liver. Kupffer cells play an important role in hepatic secretion of TNF, whereas the production of IL-6 can be achieved by other cells of the liver.

Animals↗

PubMed2001

[Perioperative management of a patient with purpura fulminans syndrome due to protein C deficiency].

PURPOSE: Protein C is a vitamin K-dependent anticoagulant and homozygous protein C deficiency is a rare fatal thrombotic disease. This report describes the perioperative management of homozygous protein C deficiency in a patient who underwent a total of three surgical procedures under general anesthesia and the successful use of activated protein C concentrate. CLINICAL FEATURES: A female baby, who developed disseminated intravascular coagulation and purpura fulminans shortly after birth, was diagnosed as purpura fulminans syndrome due to homozygous protein C deficiency. At one month of age, she suffered bilateral retinal detachment and glaucoma due to retinal hemorrhage. After marked improvement of her condition after administration of activated protein C concentrate, she underwent a left iridectomy and implantation of a Broviak catheter under general anesthesia. Her intraoperative course was uncomplicated but, on postoperative day four, she presented another episode of massive cutaneous necrosis and gangrene. Activated protein C concentrate was administered again, with good results. She underwent replacement of a Broviak catheter at four months of age, and right iridectomy for glaucoma at eight months. Both were uneventful. CONCLUSION: The perioperative management of homozygous protein C deficiency and purpura fulminans requires appropriate measures for thromboembolic prophylaxis. Sufficient iv fluid administration is necessary. Attention should be paid to decrease the risk of tissue compression such as that associated with positioning, blood pressure cuff, and endotracheal intubation, which may cause necrosis over pressure points. Replacement therapy with activated protein C concentrate appears safe and effective. The anesthetic management is reviewed and discussed.

Anesthesia, General↗

PubMed2001

Vascular endothelial growth factor enhances glomerular capillary repair and accelerates resolution of experimentally induced glomerulonephritis.

Vascular endothelial growth factor (VEGF) regulates angiogenesis through endothelial cell proliferation and plays an important role in capillary repair in damaged glomeruli. We tested the hypothesis that VEGF might be beneficial in rats with severe glomerular injury in glomerulonephritis (GN) based on its angiogenic and vascular remodeling properties. Acute GN with severe glomerular destruction was induced in rats by injection of anti-Thy-1.1 antibody (day 0) and Habu-snake venom (day 1). Rats were intraperitoneally injected with recombinant human VEGF(165) (10 microg/100 g body wt/day) or vehicle from day 2 to day 9, and monitored changes in glomerular capillaries, development of glomerular inflammation, and progression to glomerular sclerosis after acute glomerular destruction in both groups. Rats that received anti-Thy-1.1 antibody and Habu-snake venom showed severe mesangiolysis and marked destruction of capillary network on day 2. VEGF was expressed on glomerular epithelial cells, proliferating mesangial cells, and some infiltrating leukocytes, and VEGF(165) protein levels increased in damaged glomeruli during day 5 to day 7. Normal, damaged, and regenerating glomerular endothelial cells expressed VEGF receptor flk-1. However, endothelial cell proliferation and capillary repair was rare in vehicle-treated rats with severe glomerular damage, which progressed to global sclerosis and chronic renal failure by week 8. In contrast, in the VEGF-treated group, VEGF(165) significantly enhanced endothelial cell proliferation and capillary repair in glomeruli by day 9 (proliferating endothelial cells: VEGF(165), 4.3 +/- 1.1; control, 2.2 +/- 0.9 cells on day 7, P < 0.001; and glomerular capillaries: VEGF(165), 24.6 +/- 4.8; control, 16.9 +/- 3.4 capillaries on day 7, P < 0.01). Thereafter, damaged glomeruli gradually recovered after development of capillary network by week 8, and significant improvement of renal function was evident in the VEGF-treated group during week 8 (creatinine: VEGF(165), 0.3 +/- 0.1; control, 2.6 +/- 0.9 mg/dl, P < 0.001; proteinuria: VEGF(165), 54 +/- 15; control, 318 +/- 60 mg/day, P < 0.001). We conclude that the beneficial effect of VEGF(165) in severe glomerular injury in GN emphasizes the importance of capillary repair in the resolution of GN, and may allow the design of new therapeutic strategies against severe GN.

Animals↗

PubMed2001

High cyclin E and low p27/Kip1 expressions are potentially poor prognostic factors in lung adenocarcinoma patients.

Cyclin E is an important regulator of entry into the S phase of the cell cycle. p27/Kip1 (p27) binds to cyclin E/Cdk2 complex and negatively regulates cell proliferation. We immunohistochemically examined the expression of cyclin E and p27 in 98 cases of resected lung adenocarcinoma to evaluate the prognostic significance of cyclin E and p27. Cyclin E was expressed in 16 cases (16%), and p27 was expressed in 41 cases (42%). Using Kaplan-Meier survival analysis, patients with cyclin E positive (P=0.0017) and p27 negative (P=0.011), both individually and in combination (P<0.0001), had a worse prognosis. We also analyzed the relationship of these findings to clinicopathological parameters, which revealed that cyclin E-positive, p27-negative cases had a higher Ki67 expression (P=0.012) and a higher rate of lymph node metastasis (P=0.0078) than other groups. Our results suggested that cyclin E over expression, in association with p27 reduction in particular, may potentially be a poor prognostic factor in lung adenocarcinoma patients. However, to verify the prognostic significance of these factors, a multivariate analysis of a larger number of patients should be undertaken.

Adenocarcinoma↗

PubMed2001

Liver gangliosides of various animals ranging from fish to mammalian species.

Liver gangliosides of different animal species were analyzed. Bony fish liver contained a major ganglioside that migrated faster than GM3 on thin-layer chromatography (TLC). This ganglioside was identified to be GM4 (NeuAc) by methods including product analysis after sialidase treatment and negative-ion electrospray ionization (ESI)-mass spectrometry (MS). The presence of GM4 (NeuGc) in fish liver was also demonstrated. The main ganglioside band of bovine liver consisted of two different molecular species, i.e. GD1a (NeuAc/NeuAc) and GD1a (NeuAc/NeuGc). Major gangliosides of liver tissue exhibited a distinct phylogenetic profile; GM4 was expressed mainly in lower animals such as bony fish and frog liver, whereas mammalian liver showed ganglioside patterns with smaller proportions of monosialo ganglioside species. While c-series gangliosides were consistently expressed in lower animals, they were found only in mammalian liver of particular species. No apparent trend was observed between the concentration of liver gangliosides and the phylogenetic stage of animals. The present study demonstrates the species-specific expression of liver gangliosides.

Animals↗

PubMed2001

Tolerization of Gal alpha 1,3Gal-reactive B cells in pre-sensitized alpha 1,3-galactosyltransferase-deficient mice by nonmyeloablative induction of mixed chimerism.

Using a alpha 1,3-galactosyltransferase wild-type (GalT(+/+)) to deficient (GalT(-/-)) mouse bone marrow transplantation model, we have previously demonstrated that a non-myeloablative conditioning regimen is capable of permitting induction of allogeneic and xenogeneic mixed chimerism. Chimerism is associated with the rapid and lasting tolerization of anti-Gal alpha 1,3Gal (Gal) natural antibody (Ab)-producing B cells. However, one limitation of this model is that anti-Gal natural Ab levels are lower in GalT(-/-) mice than in humans and other primates. To overcome this limitation, we have now investigated the possibility of inducing such tolerance in GalT(-/-) mice that produce much higher levels of anti-Gal Abs due to presensitization with Gal-bearing xenogeneic cells. B6 GalT(-/-) mice that were pre-sensitized with rabbit red blood cells received non-myeloablative conditioning with depleting anti-CD4 and CD8 mAbs, 3Gy whole body and 7Gy thymic irradiation, and infusion of BALB/c GalT(+/+) bone marrow cells (BMC). Although engraftment of standard marrow doses was inhibited by the presensitization, long-lasting mixed chimerism could be induced in recipients of a high dose [160 x 10(6)] of allogeneic wild-type BMC. Achievement of persistent chimerism was associated with high levels of anti-Gal IgG(1) pretransplant, suggesting an inhibitory effect of non-complement-fixing IgG(1) Ab on anti-Gal-mediated marrow rejection. Induction of mixed chimerism was associated with a rapid disappearance of serum anti-Gal and tolerization of anti-Gal Ab-producing cells. B cells with anti-Gal receptors became undetectable in mixed chimeras. Mixed chimeras accepted subsequently transplanted donor-type GalT(+/+) hearts (> 140 days), whereas rapid (within 2 days) rejection of GalT(+/+) hearts occurred in conditioned control GalT(-/-) mice. In conclusion, when a high dose of GalT(+/+) BMC was administered to pre-sensitized GalT(-/-) mice, chimerism and tolerance were achieved. The absence of B cells with receptors recognizing Gal in mixed chimeras suggests a role for clonal deletion/receptor editing in the maintenance of B cell tolerance.

Animals↗

PubMed2001

Effects of specific anti-B and/or anti-plasma cell immunotherapy on antibody production in baboons: depletion of CD20- and CD22-positive B cells does not result in significantly decreased production of anti-alphaGal antibody.

Anti-Galalpha1-3Gal antibodies (antialphaGal Ab) are a major barrier to clinical xenotransplantation as they are believed to initiate both hyperacute and acute humoral rejection. Extracorporeal immunoadsorption (EIA) with alphaGal oligosaccharide columns temporarily depletes antialphaGal Ab, but their return is ultimately associated with graft destruction. We therefore assessed the ability of two immunotoxins (IT) and two monoclonal antibodies (mAb) to deplete B and/or plasma cells both in vitro and in vivo in baboons, and to observe the rate of return of antialphaGal Ab following EIA. The effects of the mouse anti-human IT anti-CD22-ricin A (proportional to CD22-IT, directed against a B cell determinant) and anti-CD38-ricin A (proportional to CD38-IT, B and plasma cell determinant) and the mouse anti-human anti-CD38 mAb (proportional to CD38 mAb) and mouse/human chimeric anti-human anti-CD20 mAb (proportional to CD20 mAb, Rituximab, B cell determinant) on B and plasma cell depletion and antialphaGal Ab production were assessed both in vitro and in vivo in baboons (n = 9) that had previously undergone splenectomy. For comparison, two baboons received nonmyeloablative whole body irradiation (WBI) (300 cGy), and one received myeloablative WBI (900 cGy). Depletion of B cells was monitored by flow cytometry of blood, bone marrow (BM) and lymph nodes (LN), staining with anti-CD20 and/or anti-CD22 mAbs, and by histology of LN. EIA was carried out after the therapy and antialphaGal Ab levels were measured daily. In vitro proportional to CD22-IT inhibited protein synthesis in the human Daudi B cell line more effectively than proportional to CD38-IT. Upon differentiation of B cells into plasma cells, however, less inhibition of protein synthesis after proportional to CD22-IT treatment was observed. Depleting CD20-positive cells in vitro from a baboon spleen cell population already depleted of granulocytes, monocytes, and T cells led to a relative enrichment of CD20-negative cells, that is plasma cells, and consequently resulted in a significant increase in antialphaGal Ab production by the remaining cells, whereas depleting CD38-positive cells resulted in a significant decrease in antialphaGal Ab production. In vivo, WBI (300 or 900 cGy) resulted in 100% B cell depletion in blood and BM, > 80% depletion in LN, with substantial recovery of B cells after 21 days and only transient reduction in antialphaGal Ab after EIA. Proportional to CD22-IT depleted B cells by > 97% in blood and BM, and by 60% in LN, but a rebound of B cells was observed after 14 and 62 days in LN and blood, respectively. At 7 days, serum antialphaGal IgG and IgM Ab levels were reduced by a maximum of 40-45% followed by a rebound to levels up to 12-fold that of baseline antialphaGal Ab by day 83 in one baboon. The results obtained with proportional to CD38-IT were inconclusive. This may have been, in part, due to inadequate conjugation of the toxin. Cell coating was 100% with proportional to CD38 mAb, but no changes in antialphaGal Ab production were observed. Proportional to CD20 mAb resulted in 100% depletion of B cells in blood and BM, and 80% in LN, with recovery of B cells starting at day 42. Adding 150cGy WBI at this time led to 100% depletion of B cells in the BM and LN. Although B cell depletion in blood and BM persisted for > 3 months, the reduction of serum antialphaGal IgG or IgM Ab levels was not sustained beyond 2 days. Proportional to CD20 mAb + WBI totally and efficiently depleted CD20- and CD22-positive B cells in blood, BM, and LN for > 3 months in vivo, but there was no sustained clinically significant reduction in serum antialphaGal Ab. The majority of antibody secretors are CD38-positive cells, but targeting these cells in vitro or in vivo with proportional to CD38-IT was not very effective. These observations suggest that CD20-and CD22-positive B cells are not the major source of antialphaGal Ab production. Future efforts will be directed towards suppression of plasma cell function.

Animals↗

PubMed2001

Porcine hematopoietic cell xenotransplantation in nonhuman primates is complicated by thrombotic microangiopathy.

Thrombotic microangiopathy (TM) is a serious complication of bone marrow transplantation (BMT) that resembles thrombotic thrombocytopenic purpura (TTP). In attempting to achieve hematopoietic cell chimerism in the pig-to-baboon model, we have observed TM following infusion of high doses (>10(10) cells/kg) of porcine peripheral blood mobilized progenitor cells (PBPC) into baboons. We performed investigations to analyze the pathobiology of this TM and to test therapeutic interventions to ameliorate it. PBPC were obtained by leukapheresis of cytokine-stimulated swine. The initial observations were made in two baboons that underwent a non-myeloablative regimen (NMR) prior to PBPC transplantation (TX) (group 1). We then studied three experimental groups. Group 2 (n = 2) received NMR without PBPC TX. Group 3 (n = 2) received PBPC TX alone. Group 4 (n = 6) received NMR + PBPC TX combined with prostacyclin, low-dose heparin, methylprednisolone, and cyclosporine was replaced by anti-CD40L mAb in five cases. Baboons in groups 1 and 3 developed severe thrombocytopenia (<10,000/mm3), intravascular hemolysis with schistocytosis (>10/high powered field (hpf)), increase in plasma lactate dehydrogenase (LDH) (2500-9000 U/l), transient neurologic changes, renal insufficiency, and purpura. Autopsy on two baboons confirmed extensive platelet thrombi in the microcirculation, and, similar to clinical BMT-associated TM/TTP, no unusually large vWF multimers or changes in vWF protease activity were observed in the plasma of baboons with TM. In group 2, self-limited thrombocytopenia occurred for 10-15 days following NMR. Group 4 baboons developed thrombocytopenia (<20,000/mm3) rarely requiring platelet transfusion, minimal schistocytosis (<3/hpf), minor increase in LDH (<1000 U/l), with no clinical sequelae. We conclude that high-dose porcine PBPC infusion into baboons induces a microangiopathic state with vWF biochemical parameters resembling clinical BMT-associated TM/TTP and that administration of antithrombotic and anti-inflammatory agents can ameliorate this complication.

Animals↗

PubMed2001

Modulation of the expression of the Cip/Kip family of cyclin-dependent kinase inhibitors in foetal developing lungs of hamsters.

We examine the cell proliferation activity and expression of cyclin-dependent kinase inhibitors of the Cip/Kip family, p21Cip1, p27Kip1 and p57Kip2, in foetal hamster lungs to determine the expression patterns of the cyclin-dependent kinase inhibitors and to clarify the relationship between expression of the cyclin-dependent kinase inhibitors and lung development. Foetal hamster lungs on gestational days 12.5-16 (the day of birth) and adult lungs were fixed in 4% paraformaldehyde. Frozen sections were immunostained for the cyclin-dependent kinase inhibitors, and examined by immunostaining for Ki-67 and bromodeoxyuridine to determine the proliferation activity of the foetal lungs. During the foetal period, cell proliferation activity, as analysed by Ki-67 or bromodeoxyuridine labelling, decreased with development of the lung. In contrast to the gradual decrease of cell proliferation activity, cells with p27Kip1 immunoreactivity increased with development. On the other hand, p21Cip1-positive cells were most prominent around gestational day 14.5, while after birth positive cells decreased markedly. A few p57Kip2-positive cells were detected in the bronchiolar epithelium on gestational day 14.5. Western blotting analyses confirmed these immunostaining patterns. Thus, the levels of the cyclin-dependent kinase inhibitors of the Cip/Kip family are modulated in the lungs during the foetal period, and each shows a unique expression pattern. The cyclin-dependent kinase inhibitors may play roles not only in regulating cell proliferation activity but also in regulating other functions such as differentiation in the lung during the foetal period.

Aging↗

PubMed2001

Pulmonary artery dissection in patients without underlying pulmonary hypertension.

AIMS: Pulmonary artery (PA) dissection is a rare event which usually occurs in patients with underlying pulmonary hypertension. We describe two patients who developed PA dissection without pre-existing pulmonary hypertension and present an extensive review of the literature. METHODS AND RESULTS: In the first patient (a 59-year-old woman), acute-onset dyspnoea was initially thought to have been caused by pulmonary thrombosis, and thromboendarterectomy was performed. Histologically, pulmonary dissection without external rupture was evident, chiefly in the right main PA. In the second patient, an 85-year-old man who had hypergammaglobulinaemia of unknown cause and died from a haemorrhagic gastric ulcer, arterial dissection was detected at autopsy. There was no underlying pulmonary hypertension in either patient. Although the true reason for the development of dissection is unclear, pre-existing inflammation was considered to be related to its formation, at least in the second case. CONCLUSIONS: A literature review indicated that idiopathic and inflammation-related PA dissection is extremely unusual. Since PA dissection is very rare, it is important to be aware of its features in order to make a correct diagnosis.

Aged↗

PubMed2001

Recovery of sexual function after nerve-sparing radical prostatectomy or cystectomy.

BACKGROUND: The recovery of sexual function (erectile function and frequency of sexual intercourse) over time after nerve-sparing radical prostatectomy or cystoprostatectomy was evaluated. METHODS: Forty-nine consecutive patients with clinically localized prostate cancer and muscle-invasive bladder cancer were treated with radical prostatectomy and radical cystoprostatectomy with a nerve-sparing procedure. Erectile function was evaluated by the circumferential change of the penis during nocturnal penile tumescence (NPT value) with an erectometer before and after surgery. Erectile function and the frequency of sexual intercourse were also evaluated with a self-administered questionnaire before and after surgery. Multivariate analysis by Cox's proportional hazards model was used to evaluate the factor(s) that affected the recovery of erectile function and sexual intercourse. RESULTS: The recovery rates of erectile function were 49% at 3 years and 79% at 5 years. For recovery of sexual intercourse the rates were 36% at 3 years and 57% at 5 years. Multivariate analysis revealed that the preoperative NPT value was the only independent factor which significantly affected the recovery of erectile function. The age at surgery was a significant factor for recovery of sexual intercourse. CONCLUSION: Nerve-sparing operations can often, but not always, provide preservation or recovery of erectile function for patients who receive radical prostatectomy or cystoprostatectomy. Recovery of erectile function depends upon the preoperative NPT value and recovery of sexual intercourse depends upon the age of the patient.

Adult↗

PubMed2001

The specificity of monoclonal antibody A2B5 to c-series gangliosides.

To examine the specificity of monoclonal antibody A2B5, four A2B5-reactive gangliosides (designated as G-1, G-2, G-3 and G-4) were purified from bonito fish brain. Ganglioside-1, -2, and -3 migrated above GD1b, below GQ1b, and far below GQ1b on thin-layer chromatography. Ganglioside-4 had the slowest chromatographic mobility and migrated below G-3. The structures of these gangliosides were characterized by overlay analysis with glycolipid-specific ligands, product analysis after sialidase or mild acid treatment, and electrospray ionization-mass spectrometry (ESI-MS). Accordingly, G-1, G-2 and G-3 were identified to be GT3, GQ1c and GP1c, respectively. The ganglioside G-4 was shown to have the following structure: NeuAc-NeuAc-NeuAc-Galbeta1-3Gal NAcbeta1-4(NeuAc-NeuAc-NeuAcalpha2-3)Galbeta1-4Glcbeta1-1'Cer. The antibody A2B5 reacted with these c-series gangliosides, but not with GD3 and other gangliosides and neutral glycosphingolipids. The antigenic epitope for A2B5 was assumed to include the trisialosyl residue connected to the inner galactose of the hemato- or ganglio-type oligosaccharide structure of gangliosides. Phylogenetic analysis of brain gangliosides using the A2B5 preparation demonstrated that c-series gangliosides are enriched in lower animals, especially bony fish of different species. The monoclonal antibody A2B5 would be a useful tool for examining the distribution and function of c-series gangliosides.

Animals↗