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Biomedical subjects

Y Kitajima

Publications and source records attributed to Y Kitajima.

229 records · Page 13Linked to original sources
PubMedDate not supplied

Differential expression of protein kinase C isozymes and small GTP-binding proteins during HL60 cell differentiation by retinoic acid and cyclic AMP: relation with phospholipase D (PLD) activation.

The differential expression of protein kinase C (PKC) isozymes and small GTP-binding proteins, and their relation to O2 generation and phospholipase D (PLD) activation were analyzed during the differentiation of human promyelocytic HL60 cells to neutrophil-like cells induced by either retinoic acid (RA) or dibutyryl cyclic AMP (dbcAMP). In response to either one of the inducers, nitroblue tetrazolium (NBT) reduction activity time-dependently increased. Although PLD activity was upregulated by dbcAMP-treatment, only a slight increase was observed in RA-treated cells. Small GTP-binding proteins Rac1, Rap1, and RhoA, which are reported to be implicated in O2- generation or PLD activation, were already expressed in undifferentiated HL60 cells and their significant changes were not detected during differentiation. The mRNAs of the cytosolic components of NADPH oxidase system, p47phox and p67phox, were present in trace amounts in undifferentiated cells. However, they rapidly increased in response to RA or dbcAMP. In response to either RA or dbcAMP, the increases were observed in cPKC isozymes (alpha, beta I, beta II) but not in other subtypes (delta, epsilon, theta, zeta) by both RT-PCR and Western blot analyses. In dbcAMP-treated cells PKC alpha increased remarkably, whereas PKC beta I and beta II mainly elevated in RA-treated cells. These results suggest the possibility that cPKCs are closely related to cell differentiation and that PKC alpha is involved in PLD activation.

Bucladesine↗
PubMedDate not supplied

Lipofibromatous hamartoma of the median nerve associated with macrodactyly and port-wine stains.

Lipofibromatous hamartoma of the nerve is a very uncommon congenital tumor. An association between this condition and vascular malformations is not well known. We present an 11-year-old girl with a lipofibromatous hamartoma of the right median nerve with macrodactyly. She had small red macules on her right neck, chest, and arm, which were diagnosed clinically as port-wine stains. The specimens of the enlarged nerves showed fibrous and fatty growth surrounding the nerve bundles and proliferation of the small veins. We suggest that this disorder can be accompanied by a vascular malformation.

Child↗
PubMedDate not supplied

Molecular cloning of a gene encoding translation initiation factor (TIF) from Candida albicans.

The differential display technique was applied to compare mRNAs from two clinical isolates of Candida albicans with different virulence; high (potent strain, 16240) and low (weak strain, 18084) extracellular phospholipase activities. Complementary DNA fragments corresponding to several apparently differentially expressed mRNAs were recovered and sequenced. A complementary DNA fragment seen distinctly in the potent phospholipase producing strain was highly homologous to the yeast translation initiation factor (TIF). The selected DNA fragment was then used as a probe to isolate its corresponding complementary DNA clone from a library of C. albicans genomic DNA. The sequence of isolated gene revealed an open reading frame of 1194 nucleotides with the potential to encode a protein of 397 amino acids with a predicted molecular weight of 43 kDa. Over its entire length, the amino acid sequence showed strong homology (78-89%) to Saccharomyces cerevisiae TIF and (63-80%) to mouse eIF-4A proteins. Therefore, our C. albicans gene was identified to be TIF (Ca TIF). Northern blot analysis in the two strains of C. albicans revealed that Ca TIF expression is 1.5-fold higher in the potent phospholipase producing strain. The restriction endonuclease digestion of genomic DNA from this potent strain revealed at least two hybridized bands in Southern blot analysis, suggesting two or more closely related sequences in the C. albicans genome.

Amino Acid Sequence↗
PubMedDate not supplied

Hair follicle nevi and accessory tragi: variable quantity of adipose tissue in connective tissue framework.

Controversy exists about the histologic differences between hair follicle nevi and accessory tragi. We examined 10 congenital lesions histologically, possible diagnoses of which were hair follicle nevi or accessory tragi. Two specimens out of the 10 had tiny, mature hair follicles surrounded by thick fibrous root sheaths, a few fat cells, and no cartilage. The subcutaneous fat cells of their bases were segmented by a connective tissue framework. They had histologic features of hair follicle nevi. One specimen had cartilage and abundant fat cells with a connective tissue framework in the nodule, as well as a conglomeration of numerous well-differentiated hair follicles. It possessed both elements of a hair follicle nevus and an accessory tragus. Seven specimens had abundant subcutaneous fat and showed a prominent connective tissue framework. These were typical accessory tragi. The present study suggests that the number of fat cells in the nodule or papule differs between these two conditions. All the lesions studied revealed a connective tissue framework in the subcutaneous fat. Histologic features of both hair follicle nevi and accessory tragi can coexist in a single lesion. Hair follicle nevi may represent incomplete accessory tragi with scant fat cells.

Adipose Tissue↗
PubMedDate not supplied

Expression of Trk tyrosine kinase receptor is a biologic marker for cell proliferation and perineural invasion of human pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a widely known severe malignancy with a poor prognosis. Perineural invasion extending to the extra-pancreatic nerve plexus, a significant concern in the treatment is frequently present in this cancer. We analyzed immunohistochemical expression of neurotrophins (NGF, BDNF, NT-3) and the cognate receptors, Trk tyrosine kinase receptor family (TrkA, B, C) and p75NGFR in 28 surgically resected PDAC specimens. A comparative study between several clinicopathologic factors and Trk receptors revealed a significant correlation between increased expression of TrkA and cancer proliferation, as well as TrkC and cancer invasion, including venous and perineural invasion. The present findings revealed a novel mechanism in PDAC progression that is mediated via a NTs-Trk interaction.

Adenocarcinoma↗
PubMedDate not supplied

Combined evaluation of NGF and p75NGFR expression is a biomarker for predicting prognosis in human invasive ductal breast carcinoma.

Nerve growth factor (NGF) is a member of the neurotrophin family and is essential for the differentiation and maintenance of neural cells. Recently, it has been reported that NGF is involved in the growth of breast cancer. On the other hand, two types of NGF receptors have been identified, a low-affinity receptor, p75NGFR, and a high-affinity receptor, TrkA. NGF-p75NGFR interaction is known to play an important role in apoptosis, whereas NGF-TrkA interaction is responsible for the survival of neural cells. We examined the relationship between clinicopathological factors, Ki-67 index, apoptotic index and the immunohistochemical expression of NGF, TrkA and p75NGFR in 71 invasive ductal breast carcinoma (IDBC) specimens. Our data indicate that positive Ki-67 expression (a labeling index exceeding 30%) correlates significantly with the positive expression of NGF (p=0.0091). Moreover, the apoptotic index was found to correlate with a strong expression of p75NGFR. Furthermore, patients who were NGF positive and p75NGFR negative had significantly poorer disease-free survival rates (p=0.0165). In contrast, those who were NGF negative and p75NGFR positive had significantly more favorable outcomes (p=0.0191). These findings suggest that a combined evaluation of NGF and p75NGFR expression is a predictive factor in the prognosis of IDBC patients.

Adult↗
PubMedDate not supplied

Demonstration of antibody to 230 kDa bullous pemphigoid antigen in lichen planus-like keratosis.

We describe a 67-year-old man with lichen planus-like keratosis associated with anti-230 kDa bullous pemphigoid antigen (BPAG1) autoantibody. The patient had noticed solitary dark brown macule more than 6 years previously on his left chest. Histological findings showed hypergranulosis, irregular acanthosis, liquefaction degeneration of basal cells, band-like infiltration of lymphocytes at the subepidermal portion, and a cleft at the basement membrane zone (BMZ), resulting in the formation of subepidermal blisters. Direct immunofluorescence findings of perilesional skin showed a linear deposition of IgG at BMZ. On indirect immunofluorescent study using normal human skin, circulating IgG autoantibody to BMZ was present in the patient's serum at a titer of 1:80. The antigen located on the epidermal site of normal skin split by 1M NaCl was reacted with the patient's serum. Immunoblot analysis using epidermal extracts demonstrated the presence of IgG antibody directed to BPAG1 in the patient's serum. These observations suggest that the presence of an antibody to BPAG1 could be caused by the damage of basal cells following lichen planus-like keratosis.

Aged↗
PubMedDate not supplied

An experience for ELISA for desmoglein 1, suggesting a possible diagnostic help to determine the initial therapy for pemphigus foliaceus.

Pemphigus foliaceus (PF) is an autoimmune skin disease in which loss of adhesion between keratinocytes (i.e., acantholysis) in the granular cell layers appears to be mediated by the binding of autoantibodies against desmoglein (Dsg) 1. Although it has been suggested that the activity of the disease is rather correlated with the titer of the antibody, there are still no precise studies on the relationships between the disease activity and the titers of autoantibody against Dsg1 by using ELISA. In this study, we performed ELISA using recombinant Dsg1 (rDsg1) as antigen on 8 patients with pemphigus foliaceus in order to examine the reliability of this test for monitoring disease severity. The resultant index values of ELISA, which were defined by the formula: (OD of tested serum - OD of negative control)/(OD of positive control - OD of negative control) X 100, ranged from 16 to 264 compared with 6.41 of cutoff index value for normal sera. A patient with an index value of 213 had severe widespread erosions with erythema and required pulse therapy of methylpredonisolone (1,000 mg/day for 3 days). A patient with an index value of 111 had a moderate severity and was successfully treated with an initial dose of 30 mg/day (0.64 mg/kg) of predonisolone. The mildest patient with an index value of 16 was controlled with only topical application of 0.05% betamethasone ointment twice a day. These results suggest that ELISA index values for rDsg1 will provide a promising tool for monitoring the disease severity and for determining the initial therapy for pemphigus foliaceus.

Adult↗
PubMedDate not supplied

Cyclin D1 is a possible predictor of sensitivity to chemoradiotherapy for esophageal squamous cell carcinoma.

BACKGROUND: Chemoradiotherapy is currently performed on patients with advanced esophageal squamous cell carcinoma (SCC). The preoperative administration revealed that the patients who responded well to chemoradiotherapy had favorable outcomes, whereas the poor responders conversely resulted in worse prognosis. The aim of this study was to identify molecular markers predicting sensitivity to chemoradiotherapy prior to this treatment. MATERIALS AND METHODS: Our clinical protocol for chemoradiotherapy for esophageal SCC were enrolled in 34 patients comprising 20 patients who underwent surgery after neoadjuvant chemoradiotherapy and 14 patients who were treated chemoradiotherapy without surgery. The expressions of cyclin D1, p53 and Ki-67 were investigated immunohistochemically in biopsy specimens obtained before the treatment from all 34 patients. The immunoreactivities were compared with responsiveness to chemoradiotherapy as evaluated by macroscopic or microscopic method. RESULTS: The mean rate of primary tumor reduction as estimated by esophagography was 75.3% in the cyclin D1 negative group whereas 42.7% reduction rate was observed in the cyclin D1 positive group. The difference in the reduction rate between cyclin D1 positive and negative groups was statistically significant (p = 0.0025). The immunoreactivities of p53 and Ki-67 did not show a significant correlation with responsiveness to chemoradiotherapy. In neoadjuvant group, patients with cyclin D1-positive tumors showed significantly worse overall survival than patients with cyclin D1-negative tumors (p = 0.0380). CONCLUSIONS: Among 34 patients with esophageal SCC, differences in the responsiveness to chemoradiotherapy were correlated with cyclin D1 immunoreactivity assessed in the biopsy specimens. Thus the cyclin D1 protein may be a useful predictor of sensitivity to concurrent chemoradiotherapy for esophageal SCC.

Adult↗
PubMedDate not supplied

Molecular cloning of a Rho family, CDC42Ca gene from Candida albicans and its mRNA expression changes during morphogenesis.

The small GTP-binding protein family regulates various cell functions in mammalian and yeast cells. In the yeast Saccharomyces cerevisiae it has been known to be involved in vegetative growth. As an initial attempt to explore the involvement of CDC42, a member of this family, in the regulation of morphological changes in Candida albicans, we isolated a gene encoding this protein (CDC42Ca) from this fungus. The sequence of isolated gene revealed an open reading frame of 570 nucleotides with the potential to encode a protein of 190 amino acids with a predicted molecular weight of 20.5 kDa. The deduced amino acid sequence was highly homologous to CDC42s from yeast (87.8%), human (76.4%) and Caenorhabditis elegans (73.7%). The CDC42Ca mRNA level showed a transient increase with a peak at 2 h after the fresh medium shift (28 degrees C) when cells synchronously formed buds, whereas it displayed a gradual increase up to 12 h after the medium shift (37 degrees C) with elongation of germ tubes. This suggests that CDC42 may play a role in the bud emergence and also germ tube formation in C. albicans.

Amino Acid Sequence↗
PubMedDate not supplied

Papular mucinosis associated with scleroderma.

A 49-year-old Japanese woman had been suffering from limited cutaneous scleroderma with papular mucinosis. Papular mucinosis was characterized by multiple, asymptomatic, elevated, skin-colored papules on the dorsal regions of the hands. Histopathological findings of the hard papules showed a marked deposition of hyaluronic acid along sclerosis in the middle and the lower parts of dermis. Serological studies revealed a positive antinuclear antibody (speckled type). Intravenous administration of prostaglandin E1 derivatives reduced the size of the papules, the degree of sclerodactyly and the severity of her Raynaud's phenomenon. These observations suggest that manifestations of scleroderma could be found in some cases of papular mucinosis.

Alprostadil↗
PubMedDate not supplied

Antibody to bullous pemphigoid antigen 1 binds to the antigen at perilesional but not uninvolved skin, in localized bullous pemphigoid.

We describe a 59-year-old woman who presented with vesicles, bullae and crusts on her lower legs. Direct immunofluorescence findings for perilesional skin showed linear depositions of IgG and C3 at the basement membrane zone, while no deposition was observed in intact thigh skin, 20 cm distant from the edge of the erosion. On indirect immunofluorescence study using normal human skin, circulating IgG autoantibody to the basement membrane zone (BMZ) was observed in the patient's serum at a titer of 1: 160, which reacted with an antigen located on the epidermal side of normal skin split by 1M NaCl and which stained the BMZ of the thigh skin of the patient that was negative in direct immunofluorescence study. Immunoblot analysis using epidermal extracts demonstrated the presence of IgG antibody directed to 230 kDa bullous pemphigoid antigen (BPAG1) in the patient's serum. These findings suggest that antibody to BPAG1 binds to an antigen uncovered by unknown causes at perilesional, but not at uninvolved skin in the present case of localized bullous pemphigoid.

Autoantibodies↗