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Biomedical subjects

T Kishida

Publications and source records attributed to T Kishida.

At least 127 records · Page 7Linked to original sources

Germline mutations in the von Hippel-Lindau disease tumor suppressor gene: correlations with phenotype.

von Hippel-Lindau disease (VHL) is an inherited neoplastic disease characterized by a predisposition to develop retinal angiomas, central nervous system hemangioblastomas, renal cell carcinomas, pancreatic cysts, and pheochromocytomas. The VHL gene was recently isolated by positional cloning. The cDNA encodes 852 nucleotides in 3 exons. The VHL gene is unrelated to any known gene families. We identified germline mutations in 85/114 (75%) of VHL families. Clinical heterogeneity is a well-known feature of VHL. VHL families were classified into 2 types based on the presence or absence of pheochromocytoma. The types of mutations responsible for VHL without pheochromocytoma (VHL type 1) differed from those responsible for VHL with pheochromocytoma (VHL type 2). Fifty-six % of the mutations responsible for VHL type 1 were microdeletions/insertions, nonsense mutations, or deletions; 96% of the mutations responsible for VHL type 2 were missense mutations. Specific mutations in codon 238 accounted for 43% of the mutations responsible for VHL type 2. The mutations identified in these families will be useful in presymptomatic diagnosis. The identification of mutations associated with phenotypes contributes to the understanding of fundamental genetic mechanisms of VHL disease.

Adrenal Gland Neoplasms↗

Von Hippel-Lindau (VHL) disease with pheochromocytoma in the Black Forest region of Germany: evidence for a founder effect.

We identified a germline missense mutation at nucleotide 505 (T to C) of the VHL tumor suppressor gene in 14, apparently unrelated, VHL type 2A families from the Black Forest region of Germany. This mutation was previously identified in two VHL 2A families living in Pennsylvania (USA). All affected individuals in the 16 families shared the same VHL haplotype indicating a founder effect. This missense mutation at codon 169 (Tyr to His) would probably cause an alteration in the structure of the putative VHL protein. The association of this distinct mutation with the pheochromocytoma phenotype in VHL may help to elucidate the genetic mechanism of carcinogenesis in this multi tumor cancer syndrome.

Adrenal Gland Neoplasms↗

Diagnosis of preterm premature rupture of the membranes using a newly developed AFP monoclonal antibody test kit.

OBJECTIVE: We have developed a new anti-AFP monoclonal antibody kit which is easier to use than other examination methods for detecting AFP in the leaked amniotic fluid. In this study, we investigate the clinical value of this test in the diagnosis of preterm premature rupture of the membranes (PROM). METHODS: We employed 103 patients of less than 37 weeks of gestational age for this preliminary study. We compared the clinical usefulness of this new AFP test with that of the nitrazine test and measured the concentration of AFP in vaginal fluid or cervical secretion by EIA. RESULTS: The nitrazine test showed a correct diagnostic rate of 62.1%, in contrast the AFP test kit had a 98.0% rate (P < 0.001). The reaction time using the kit is 3 min. CONCLUSION: The AFP test is a simple and non-invasive test which can be easily carried out repeatedly as a bedside examination. This study has confirmed the high clinical efficacy of the newly developed AFP test kit as a method of PROM diagnosis.

Amniotic Fluid↗

Clinical usefulness of the dye-injection method for diagnosing premature rupture of the membranes in equivocal cases.

OBJECTIVE: In 1981, we preliminarily reported on the clinical value and safety of the intra-amniotic dye (Phenol-sulfonphthalein, PSP)-injection method for diagnosing PROM. In the current study, through examination of 64 equivocal cases in the midtrimester of pregnancy, we investigated the clinical efficacy of the PSP test. METHODS: In the present study we examined patients with equivocal PROM in their 14th week to 33rd week of gestation, whose findings were positive according to a combination of conventional diagnostic methods. The results of the PSP test and conventional diagnostic methods were compared with the final diagnosis of PROM. RESULTS: The conventional diagnostic methods showed an accuracy rate of 63.9%-70.5%, in contrast to the PSP test, which had a 100%-accuracy rate (p < 0.001). CONCLUSION: Using the PSP test in combination with amnioscopy, we have established a method of differentially diagnosing PROM. We have reconfirmed the clinical efficacy of the PSP test in 64 equivocal PROM cases.

Female↗

Detection of germline mutations in the von Hippel-Lindau disease gene by the primer specified restriction map modification method.

Von Hippel-Lindau disease (VHL) is an inherited disorder characterised by a predisposition to develop tumours in the eyes, central nervous system, kidneys, and adrenal glands. Recently the VHL gene was cloned and shown to be mutated in 75% of US and Canadian VHL families. To develop simple, rapid methods for the detection of mutations found in large numbers of affected people, we designed based on the primer specified restriction site modification method. These tests have proved useful in identifying asymptomatic mutated VHL gene carriers who have the nt 505 T to C mutation or the nt 686 T to C mutation. Together with an MspI digestion test which can detect a mutation hot spot in codon 238, polymerase chain reaction/restriction endonuclease based tests can now detect VHL mutations in more than 50% of VHL type 2 families.

Base Sequence↗

[Prognostic factors for metastatic renal cell cancer].

We examined various prognostic factors of metastatic renal cell carcinoma. Patients who had metastasis at nephrectomy (A group, 38 cases) and those who had metastasis as recurrent tumors after nephrectomy (B group, 38 cases) entered in this study. Five-year survival rate of total cases after confirmation of metastatic foci was 15% and there was no statistical significant difference between A and B groups. Several pathological factors were related to poorer prognosis and included large diameters of original tumors, positive lymph nodes, higher grade tumors and non-clear cell type tumors. Patients who have a solitary lung metastasis showed better prognosis compared to those with multiple lung metastases or metastases of other organs. Two factors related to treatment were shown to contribute to better prognosis. These were the response to interferon alfa (IFN alpha) and the possibility of total resection of visible metastatic tumors. Patients who belong to A group were shown to achieve markedly better therapeutic benefit from IFN alpha or IFN alpha plus anticancer drugs. Five-year survival rate for the responders was 40%, as compared to less than 5% for the non-responders. Ten-year survival rate for patients with metastasis who had undergone complete resection of visible tumor was 50%, and the for patients belonging to B group Showed 80%. We concluded that these prognostic factors should be considered to decide how to select patients with metastatic renal cell cancer.

Adult↗

Preparation of multi-locus DNA probe cocktail by liquid-phase reassociation.

We developed a simple, rapid method for the preparation of a DNA-fingerprinting probe cocktail, and tested its usefulness in paternity testing. Exploiting the property of tandemly repetitive DNA segments to be rapidly renatured after heat denaturation, we enriched restriction fragments of a child's genomic DNA for minisatellites by liquid phase reassociation followed by capture with immobilized streptavidin. We amplified and simultaneously labeled the reassociation product by anchored PCR using a digoxigenin-labeling mixture. Using this probe cocktail, we were able to detect fingerprints of paternity case trios, and the results were corroborated by DNA fingerprinting with a commercially available probe as well as by conventional phenotyping. Our method enables one to prepare a fresh cocktail of probes from the DNA sample under study during the overnight electrophoresis and Southern transfer steps in DNA fingerprinting, and eliminates the need of having an expensive probe of limited shelf life. If one has a practical outlook on DNA fingerprinting and regard it as a preliminary test, one does not have to use a cloned DNA probe. The present study demonstrates that a multi-locus probe cocktail serves such a practical purpose.

Base Sequence↗

Retinoblastoma gene mutation in primary human renal cell carcinoma.

We searched for possible mutations in the E2F-binding region of retinoblastoma gene in primary human renal cell carcinomas, using polymerase chain reaction and single-strand conformational polymorphism analysis of RNA. Retinoblastoma gene mutation was detected in 1 of 21 cases (5%). DNA sequencing of the polymerase chain reaction product verified that this case had a 6-base deletion at the beginning of exon 8. Our findings suggest that mutation of the retinoblastoma gene is involved in only a subgroup of sporadic human renal cell carcinomas.

Base Sequence↗

Diagnosis of premature rupture of membranes with an improved alpha-fetoprotein monoclonal antibody kit.

We developed a new kit for detecting alpha-fetoprotein (AFP) in leaked amniotic fluid (Eur J Obstet Gynecol Reprod Biol 1995;58:67-72). Later, we developed an improved AFP kit utilizing the same AFP monoclonal antibody. We compared this improved AFP test with the nitrazine test for 137 patients. The nitrazine test correctly diagnosed 62.1% of the cases, but the improved AFP kit diagnosed 98.0% for < 37 weeks of gestation (P < 0.001). The nitrazine test showed a specificity of 58.3%, whereas the AFP kit showed a 100% rate for detecting > or = 37 weeks of gestation (P < 0.01). The reaction time with the AFP kit is 90 s. This study has confirmed a high clinical efficacy of the improved AFP test kit as a method of diagnosis of premature rupture of fetal membranes.

Amniotic Fluid↗

PCR amplification of D2S44 (YNH24) alleles.

We have successfully amplified D2S44 (YNH24) alleles by a method for long-distance PCR using a special polymerase enhancer, Taq Extender PCR Additive. The alleles amplified from DNA samples of 58 Japanese subjects ranged from 0.42 to 3.5 kb and were 1.5 kb shorter than those detected by Southern blotting of Hinf I-digested genomic DNAs. Although alleles longer than 3 kb were barely visible by ethidium bromide staining, we were able to visualize them clearly with SYBR GREEN I NUCLEIC ACIC GEL STAIN. PCR amplification of D2S44 alleles is much simpler than their restriction fragment length polymorphism (RFLP) analysis; therefore, our procedure is well-suited for use in medicolegal practice. With minor modifications, the method described here should be applicable to other loci of variable number of tandem repeats (VNTRs) that have been analyzed by Southern blotting.

Alleles↗

Vaginal and cervical pH in bacterial vaginosis and cervicitis during pregnancy.

The purpose of our study is to see whether vaginal and cervical pH are helpful to screen for bacterial vaginosis and cervicitis during pregnancy. One hundred and seven pregnant women underwent prospectively both vaginal pH and cervical pH measurement and screening for microbial infections of the lower genital tracts at 10, 20 and 30 gestational week between February 1993 and August 1993. The value of vaginal pH significantly elevated in bacterial vaginosis (P < 0.05). Vaginal pH values also significantly elevated in patients who had had sexual intercourse 2 days before the dates of examinations (P < 0.01). Cervical pH value exhibited no significant change in bacterial vaginosis and cervicitis. Vaginal pH is a valid indicator for screening of bacterial vaginosis during pregnancy. However, vaginal pH might be influenced by the presence of semen. Cervical pH is not a useful parameter for screening of cervicitis during pregnancy.

Cervix Uteri↗

Frequent somatic mutations and loss of heterozygosity of the von Hippel-Lindau tumor suppressor gene in primary human renal cell carcinomas.

We analyzed 47 primary sporadic human renal cell carcinomas (39 clear cell and 8 non-clear cell) for mutations of the von Hippel-Lindau (VHL) tumor suppressor gene using the polymerase chain reaction and single strand conformational polymorphism analysis of DNA. All of the positive cases in single strand conformational polymorphism analyses were further characterized by direct sequencing. Somatic mutations were detected in 22 (56%) of 39 clear cell renal carcinomas including 15 deletions, 3 insertions, 3 missense mutations, and 1 nonsense mutation. Nineteen of these mutations predicted to produce truncation of the VHL protein. These mutations mainly occurred in the last one-third region of exons 1, 2, and 3. In addition, loss of heterozygosity of the VHL gene was observed in 16 (84%) of 19 informative clear cell renal carcinomas. No somatic mutations were detected in 8 non-clear cell carcinomas. These results show that the VHL tumor suppressor gene is one of the major tumor suppressor genes in human renal cell carcinomas, especially in the clear cell subtype renal cell carcinoma. Clear cell carcinoma might be distinguished from other pathological types of renal cell carcinomas by molecular genetic techniques.

Base Sequence↗

Clinical significance of serum iron and ferritin in patients with colorectal cancer.

To clarify the significance of serum iron and ferritin as indicators of iron loss caused by continuous bleeding, and, thus, to determine their value as markers of colorectal cancer, values for the two were compared in male patients with early and advanced colorectal cancer and age-matched male controls. The mean value of serum iron levels in patients with advanced colorectal cancer was significantly decreased compared with values in patients with early colorectal cancer and controls, 50.5 +/- 38.6 micrograms/dl vs 93.0 +/- 32.1 micrograms/dl and 107.1 +/- 32.9 micrograms/dl, respectively (p < 0.001). The mean value of serum ferritin levels in patients with early and advanced colorectal cancer was also significantly decreased compared with controls, 80.5 +/- 35.0 ng/ml (p < 0.01) and 48.8 +/- 72.8 ng/ml (p < 0.001), respectively, vs 117.1 +/- 46.8 ng/ml. However, there was no significant difference between mean serum iron levels in patients with early colorectal cancer and controls. Eighteen (78.3%) of the 23 patients with advanced colorectal cancer and 3 (16.7%) of the 18 patients with early colorectal cancer had serum iron levels below 85 micrograms/dl and serum ferritin levels below 60 ng/ml. Levels of both serum iron and ferritin, without clinically evident anemia, are useful indicators of advanced colorectal cancer.

Aged↗

[Definite diagnosis of premature rupture of the membranes (PROM) using intra-amniotic dye injection method and development of a new kit (AFP-test kit) for PROM diagnosis].

In the diagnosis of premature rupture of the membranes (PROM) in the mid-trimester of pregnancy, it is often difficult to obtain reliable information from only an analysis of the amniotic fluid, especially in equivocal cases. In cases where we have not been able to obtain a definite diagnosis of PROM by conventional methods including amnioscopy, we have employed the intra-amniotic dye injection method (PSP method) by abdominal amniocentesis. We have established the method to be good for discrimination of high-leak and low-rupture PROM as well as the rupture of the pseudo-amniotic cavity, and have preliminarily reported on the clinical usefulness and safety of the PSP method since 1981. In this study, through examination of 64 equivocal PROM cases, we have investigated the clinical efficacy of the PSP method for cases in their 14th to 33rd week of gestation. The conventional methods showed a correct diagnostic rate of 63.9%-70.5%, in contrast the PSP method had a 100% rate. We have reconfirmed the clinical efficacy of the PSP method. The PSP method has been proven to be a reliable PROM diagnostic method, but employed for a selected doubtful cases. A non-invasive, reliable and rapid method which can be employed in a repeated manner as a bed-side examination, has been needed for many years. Amniotic fluid contains a high concentration of alpha-fetoprotein(AFP), especially in mid-trimester, and undetectable levels are determined in urine, vaginal fluid and seminal fluid. We have developed a new anti-AFP monoclonal antibody kit for PROM diagnosis. In the present study, we investigated the fundamental ability of AFP-test kit and the clinical efficacy of this kit for 71 cases in their 11th to 40th week of gestation with PROM or suspected PROM. The AFP-test kit method showed a correct diagnostic rate of 100%. The reaction time of this kit is approximately 3 minutes. It is a simple and non-invasive test which can be easily carried out repeatedly as a bed-side examination. This study has confirmed the high efficacy of the AFP-test kit as a method of PROM diagnosis.

Amniocentesis↗

Universal probe system for DNA fingerprinting.

A universal probe system is a combination of an unlabeled primary probe that has been inserted in a cloning vector and a labeled secondary probe that is specific to the vector. This system is time- and labor-saving in that one does not need to label probes every time one uses them, so long as they are inserted in the same vector. As a first step in the preparation of a universal probe system for DNA fingerprinting, we isolated multi-locus probes from a subgenomic library that had been constructed by insertion into the phagemid pUC118 of 1-2 kb fragments of DNA from human myeloma cells. Next, we isolated single-stranded DNAs of recombinant phagemids, and hybridized them with Southern blots of DNAs from mother-child-father trios or unrelated individuals. As with double-stranded DNA probes, we were able to detect DNA fingerprints, with a commercially available, alkaline phosphatase-labeled secondary probe or a digoxigenin-labeled universal sequencing primer.

DNA Fingerprinting↗