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Biomedical subjects

Hiroshi Nishikawa

Publications and source records attributed to Hiroshi Nishikawa.

At least 19 recordsLinked to original sources
PubMed2006

Effects of cyanide and dissolved oxygen concentration on biological Au recovery.

The number of discarded electric devices containing traces of Au is currently increasing. It is desirable to recover this Au because of its valuable physicochemical properties. Au is usually dissolved with relatively high concentrations of cyanide, which is associated with environmental risk. Chromobacterium violaceum is able to produce and detoxify small amounts of cyanide, and may thus be able to recover Au from discarded electric devices. This study investigated the effects of cyanide and dissolved oxygen concentration on biological Au recovery. Cyanide production by C. violaceum was sufficient to dissolve Au, while maintaining a high cyanide concentration did not enhance Au dissolution. Increased oxygen concentration enhanced Au dissolution from 0.04 to 0.16 mmol/l within the test period of 70 h. Electrochemical measurement clarified this phenomenon; the rest potential of Au in the cyanide solution produced by C. violaceum increased from -400 to -200 mV, while in the sterile cyanide solution, it was constant in cyanide concentrations ranging from 0 to 1.5 mmol/l and increased in dissolved oxygen concentrations ranging from 0 to 0.25 mmol/l. Therefore, it was clarified that dissolved oxygen concentration is the main factor affecting the efficiency of cyanide leaching of gold by using bacteria.

Biodegradation, Environmental↗
PubMed2006

Elevated serum RANTES levels in patients with ovarian cancer correlate with the extent of the disorder.

OBJECTIVE: To assess the clinical relevance of serum regulated upon activation, normal T-cell expressed and secreted (RANTES) levels in distinguishing patients with ovarian cancers from those with benign ovarian cysts, we measured its concentration with reference to the disease stage, pathological grading, histological subtype, and the residual tumor mass. METHODS: Preoperative serum RANTES levels were measured in women with invasive epithelial ovarian cancer (n = 52), borderline ovarian tumor (n = 6), benign ovarian cysts (n = 28), or normal controls (n = 12) using an enzyme-linked immunosorbent assay. RESULTS: The serum RANTES concentration was significantly elevated in the ovarian cancer patients (median 53 ng/ml, interquartile range 23-104 ng/ml) compared to the benign ovarian cyst patients as controls (38 ng/ml, 5-72 ng/ml) values correlating with the stage of disease and the extent of residual tumor mass. No significant correlation between CA125 and RANTES in the serum was observed in either the controls or the ovarian cancer patients. Using a RANTES cutoff of 45 ng/ml and a CA125 cutoff of 35 units/ml, when either marker was elevated, the specificity improved 94%. CONCLUSION: Our study suggest that preoperative serum RANTES levels may be useful in differentiating benign ovarian tumors from malignancy correlating with the extent of the disorder.

Adult↗
PubMed2006

Acute exacerbation of macroglossia leading to necrosis of the anterior third of the tongue.

Macroglossia is defined as an enlarged tongue that protrudes beyond the teeth or the alveolar ridge in the resting position. Macroglossia may be classified into generalised and localised based on the extent of tongue involvement. Each of these groups can be subdivided into congenital, inflammatory, traumatic, metabolic and neoplastic lesions [Myer III CM, Hotaling AJ, Reilly JS. The diagnosis and treatment of macroglossia in children. Ear Nose Throat J 1986;65:444-8]. The congenital causes are vascular anomalies such as haemangioma and lymphovenous malformations. We report the case of a large lymphovenous malformation of the tongue in a 17 month old child who developed an acute exacerbation of macroglossia following trauma. This eventually led to necrosis of the anterior third of his tongue requiring a partial glossectomy.

Accidental Falls↗
PubMed2006

Sympathetic paraganglioma presenting with Horner's syndrome in a child.

Paragangliomas of the head and neck arise from collections of cells from the neural crest associated with cranial or sympathetic nerves. Such lesions are rare in children. The majority of paragangliomas in the paediatric age groups have been familial, occurring in association with an adrenal pheochromocytoma. Children typically present with a neck mass and systemic evidence of catecholamine hypersecretion. We present the case of a 12-year-old boy with a history of increasing headache, drowsiness and Horner's syndrome for 8 months. The patient underwent exploration of the neck mass under general anaesthesia. The lesion was found to be in continuity with the left sympathetic chain. It was highly vascular but was removed en mass and sent for histological analysis. The histology showed that the mass was a well-circumscribed encapsulated tumour and that complete excision was achieved. The post-operative period was uneventful and the patient recovered well after the operation. On review at 6 months following surgery, his scars were maturing satisfactorily but the Horner's syndrome was persistent. Sympathetic chain paragangliomas are very rare tumours in the head and neck but should be considered in the differential diagnosis when clinical and radiographic evidence suggest a paraganglioma. The presentation is typically of a slow-growing neck mass with the presence of an ipsilateral Horner's syndrome. To our knowledge, this is the first reported case of a sympathetic chain paraganglioma in a child.

Autonomic Nervous System Diseases↗
PubMed2005

Preoperative serum thrombopoietin levels are higher in patients with ovarian cancer than with benign cysts.

OBJECTIVE: To assess the diagnostic relevance of serum thrombopoietin (TPO) levels, we compared serum TPO levels between the patients with ovarian cancer and benign ovarian cysts. We also correlated serum TPO concentrations in ovarian cancer patients to know prognostic factors such as disease stage, tumor grade, histological subtype, and residual tumor mass. STUDY DESIGN: Preoperative serum TPO levels were measured in women with epithelial ovarian cancer (n=51) and women with benign ovarian cysts (n=25) using an enzyme-linked immunosorbent assay. RESULTS: The serum TPO concentration was significantly elevated in the ovarian cancer patients as compared to the benign patient controls. Platelet counts and TPO in the serum did not correlate in the ovarian cancer patients. However, using a TPO cutoff of 90 pg/ml and a CA125 cutoff of 30 units/ml, when both markers were elevated, the specificity was as high as 92%. CONCLUSION: Serum TPO concentrations may have a role in the diagnostic clinical setting for discerning benign from malignant ovarian tumors.

Biomarkers↗
PubMed2005

Chemoprevention of acrylamide toxicity by antioxidative agents in rats--effective suppression of testicular toxicity by phenylethyl isothiocyanate.

The efficacies of N-acetylcysteine (NAC), phenylethyl isothiocyanate (PEITC), and 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ) at preventing the neurotoxicity and testicular toxicity of acrylamide (ACR) were investigated in rats. To this end, Sprague-Dawley males were given 0.02% ACR in drinking water, with or without 1% NAC, 0.5% PEITC or 0.1% HTHQ in the diet for four weeks. A group of untreated controls was also included in the study. All ACR-treated animals exhibited progressive neurotoxicity as judged by gait scores, and among the chemicals co-administered, only HTHQ caused any suppression by the end of the experiment, and this was slight. The severity of the neurotoxicity, as judged by axonal degeneration in the spinal gracile fasciculus and sciatic nerve (distal portion) and aberrant dot-like synaptophysin immunoreactivity, reflecting nerve terminal degeneration in the cerebellar molecular layer, was not clearly reduced by co-administration of HTHQ, NAC or PEITC either. ACR-induced sciatic nerve axon atrophy was marginally and non-significantly reduced by HTHQ. In contrast, in terms of ACR-induced testicular toxicity, exfoliation of spermatids into seminiferous lumen was clearly reduced by co-administered PEITC and was marginally reduced by co-administered HTHQ. These antioxidative agents may therefore reduce/prevent ACR-induced toxicity, at least in the testes.

Acrylamide↗
PubMed2005

Use of serum secretory leukocyte protease inhibitor levels in patients to improve specificity of ovarian cancer diagnosis.

OBJECTIVE: To assess the clinical relevance of serum secretory leukocyte protease inhibitor (SLPI) levels in distinguishing patients with ovarian cancers from those with benign ovarian cysts, we determined concentrations with reference to the FIGO stage and other clinical characteristics. METHODS: Preoperative serum SLPI levels were measured in women with invasive epithelial ovarian cancer (n = 55), benign ovarian cysts (n = 25), or normal controls (n = 38) using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The serum SLPI concentration was significantly elevated in the ovarian cancer patients (median 67 ng/ml, interquartile range 26-124 ng/ml) as compared to the benign cyst patients (37 and 25-66 ng/ml) or healthy women (32 and 25-43 ng/ml). Using an SLPI cutoff of 50 ng/ml and a CA125 cutoff of 30 units/ml, with both markers elevated the sensitivity was 95%, the specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 89% between the malignant and benign cyst patients. CONCLUSION: Serum SLPI levels could be useful for differentiating benign ovarian cysts from malignancies and to improve the specificity of diagnosis.

CA-125 Antigen↗
PubMed2005

Chemosensitivity in pediatric dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a rare tumor of fibrohistiocytic spectrum and uncommonly presents in infancy and childhood. The standard treatment is wide-margin surgical excision, but this is difficult to achieve in large tumors and may result in unacceptable cosmetic, structural, and functional consequences. The authors describe a child with recurring DFSP who, after extensive surgery, responded to treatment with vinblastine and oral methotrexate. This is the first reported case in literature of a chemotherapeutic response in pediatric DFSP.

Administration, Oral↗
PubMed2004

Structure-activity relationships of adenosine A3 receptor ligands: new potential therapy for the treatment of glaucoma.

Structure-activity relationships (SAR) of fused 1,2,4-triazolo[1,5-c ]pyrimidine were performed. Various substituents were introduced into the heterocyclic ring to improve the potency of adenosine A(3) receptor binding affinity and A(3)-selectivity against other subtypes. Potent and selective A(3) receptor antagonists were identified and were evaluated in a monkey model of intraocular pressure by eye-drop administration. As a result, compound 1c (OT-7999) was found to significantly decrease intraocular pressure in the animal model.

Adenosine A3 Receptor Antagonists↗
PubMed2004

Management of pyopagus conjoined twins.

INTRODUCTION: Approximately 18% of conjoined twins (1 in 200,000 live births) are joined at the sacrum ("pyopagus"). As the joined structures are not life-threatening, there is generally a good prognosis, with time for investigation and planning of operative separation. CASE REPORT: This paper reports on the management of pyopagus twin girls, the first in the UK delivered at 36 weeks by Caesarean section. The diagnosis had been made by ultrasound at 12 weeks' and confirmed by MRI scan at 26 weeks' gestation. Each twin had wasting and weakness below one knee, but no deficit in the other leg. The perineum had two urethras but only one anus. One infant had a colostomy in the immediate neonatal period. With appropriate further imaging, surgery was planned in two stages. First, a balloon expander was inserted in the bridging area. At 3 months of age a team comprising Plastic, Paediatric and Neurosurgeons undertook the definitive separation. DISCUSSION: Details of the multidisciplinary planning, operative separation and follow-up of these two children will be discussed.

Female↗
PubMed2004

Facile synthesis of fused 1,2,4-triazolo[1,5-c]pyrimidine derivatives as human adenosine A3 receptor ligands.

A facile synthetic method for fused triazolopyrimidine derivatives having high affinity and selectivity for human adenosine A(3) receptors is reported. The fused triazolopyrimidine derivatives were easily prepared by one-pot reaction using acylhydrazines and imidates prepared from amine derivatives bearing cyano group and orthoesters in situ. This synthetic method was useful in finding new tricyclic adenosine A(3) receptor antagonists and also in diversifying the substituents at two positions on the fused triazolopyrimidine ring.

Adenosine A3 Receptor Antagonists↗
PubMed2004

Early presentation of an extremity arteriovenous malformation.

We report a very rare case of a high flow arteriovenous malformation (AVM) of the upper limb that caused high output cardiac failure at birth. There was early transfer of the baby to the care of a multidisciplinary team. After radiological intervention, the arm distal to the malformation became ischaemic and an urgent amputation through the upper-humerus followed. Methods of treatment are discussed, together with a review of results in the literature.

Amputation, Surgical↗
PubMed2004

The role of cathepsin B and cystatin C in the mechanisms of invasion by ovarian cancer.

OBJECTIVE: The aim of this study was to investigate the contribution of cathepsin B and cystatin C to the mechanisms of invasion by ovarian cancer. MATERIALS AND METHODS: Using surgical materials from patients with ovarian cancer, immunohistochemistry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis were performed using antibodies against cathepsin B or cystatin C. Serum levels of cathepsin B and cystatin C in patients with benign and malignant ovarian lesions were determined by enzyme-linked immunosorbent assay (ELISA). An invasion assay using an ovarian cancer cell line was performed by addition of cystatin C or specific inhibitors of cathepsin B. RESULTS: While immunohistochemical staining of cathepsin B and cystatin C was evident in cancer cells and associated stromal tissue, this was not the case in benign tumors. The malignancies were also found to be positive for cathepsin B and cystatin C by SDS-PAGE and Western blotting analysis. No significant difference in serum cathepsin B levels was observed between patients with benign and malignant disease. However, the concentration of cystatin C in cases with ovarian cancer was significantly higher in benign cases (P<0.0001) and in healthy controls (P<0.0001). Invasion by cancer cells was dose-dependently suppressed by cystatin C and cathepsin B inhibitors. CONCLUSION: The results provided convincing evidence that cathepsin B and cystatin C may contribute to the mechanisms of invasion of ovarian cancer.

Adolescent↗
PubMed2003

Maxillary volume growth in childhood.

Nasomaxillary abnormalities in form, position, and development in children are often prominent features of craniosynostosis, and in particular, craniofacial dysostosis. While attempting to quantitatively assess the volumetric maxillary deficiency in these patients, it became apparent that there was no "normal" reference range for maxillary volumes throughout childhood that could be used for comparison. The aim of this study was to generate a model for measuring maxillary volume and subsequent changes throughout childhood. The technique of segmentation was applied to magnetic resonance images obtained in 55 healthy children (30 boys, 25 girls), aged 1 month to 184 months (15.33 years). Maxillary volumes were plotted against age for boys and girls to create a model for normal maxillary growth during the first 15 years of life. Maxillary volumes were larger in boys at all ages. However, the pattern of maxillary growth in boys and girls was similar and could be divided into three periods, each lasting approximately 5 years. During the first 5 years of life, there is a steady increase in maxillary volume, at the end of which the maxilla has reached 53 percent of the volume recorded at 15 years. There is an accelerated rate of growth between 5 and 11 years, which corresponds to the development and eruption of the permanent dentition. Thereafter, until the age of 15 years, the rate of growth of the maxilla plateaus. Maxillary volume in the first 12 months of life is, on average, 29 cm3 in boys and 25 cm3 in girls. By 15 years of age, it has increased to an average of 73.0 cm3 in boys and 59.4 cm3 in girls (an increase by a factor of 2.5 in boys and 2.4 in girls). The difference between the two sexes is statistically significant for the entire series (boys: mean maxillary volume = 56.55 cm3, SD = 24.61; girls: mean maxillary volume = 40.68, SD = 17.69, p = 0.009, one-way analysis of variance).

Adolescent↗
PubMed2003

Maxillary volume growth in craniosynostosis.

Craniosynostosis, and in particular, craniofacial dysostosis, exhibits abnormalities of the nasomaxillary complex in form, position, and development. The aim of this study was to quantitatively assess the volumetric maxillary abnormality in patients at the time of initial diagnosis of craniosynostosis and to make comparisons with a "normal" reference range for maxillary volumes throughout childhood. The technique of segmentation was applied to preoperative computed tomographic head scans obtained in 31 children (14 boys, 17 girls), between 1 and 34 months of age (mean, 11.06 months), who underwent cranial expansion surgery for craniosynostosis affecting the coronal suture complex. Maxillary volumes were plotted against age for the first 3 years of life and were compared with a healthy population. There was no statistical difference between the two sexes for mean maxillary volume. The mean maxillary volumes for the entire group were statistically smaller than the norm (p = 0.046, linear regression with age as a covariable), but there was no statistical difference among the four different groups of coronal synostosis (unilateral coronal, nonsyndromic bilateral coronal, nonsyndromic complex pansynostosis, syndromic bilateral coronal synostosis) (p = 0.407, one-way analysis of variance). On graphic data analysis, the maxillary volume was smaller than the norm in craniosynostotic children who presented in the first few months of life. However, by 7 months of age in nonsyndromic bilateral coronal synostosis and by 17 months of age in syndromic bilateral coronal synostosis, the maxillary volumes had increased toward the norm. This implies that the effect of the craniosynostotic process on the midface structures is present from birth and parallels the effect on the cranial vault sutures.

Age Factors↗
PubMed2003

Experimental protection of mice against lethal Staphylococcus aureus infection by novel bacteriophage phi MR11.

The protective effects of bacteriophages were assessed against experimental Staphylococcus aureus infection in mice. Of the S. aureus phages isolated in the study, phi MR11 was representatively used for all testing, because its host range was the most broad and it carries no genes for known toxins or antibiotic resistance. Intraperitoneal injections (8 x 10(8) cells) of S. aureus, including methicillin-resistant bacteria, caused bacteremia and eventual death in mice. In contrast, subsequent intraperitoneal administration of purified phi MR11 (MOI > or = 0.1) suppressed S. aureus-induced lethality. This lifesaving effect coincided with the rapid appearance of phi MR11 in the circulation, which remained at substantial levels until the bacteria were eradicated. Inoculation with high-dose phi MR11 alone produced no adverse effects attributable to the phage. These results uphold the efficacy of phage therapy against pernicious S. aureus infections in humans and suggest that phi MR11 may be a potential prototype for gene-modified, advanced therapeutic S. aureus phages.

Animals↗