Studies on relationship between testicular capsule and sperm transport in rat testis.

Aim: In SD rats, histological changes in the testis were observed after bilateral capsulotomy (of the tunica albuginea) in order to investigate the physiological role of the testicular capsule on sperm transport.

Methods: Bilateral longitudinal capsulotomy was devised to disrupt the capsular contractile function. With this technique, only the tunica vaginalis and tunica albuginea were slit open, leaving the tunica vasculosa intact to embrace the underlying testicular parenchyma.

Effect of testicular capsulotomy on secretion of testosterone and gonadotrophins in rats.

Aim: In order to clarify further the mechanisms underlying the effect of capsulotomy on testicular function, the levels of testosterone, LH and FSH were observed.

Methods: Intratesticular testosterone levels and LH, FSH levels in the peripheral blood of normal, sham-operated and capsulotomized rats were detected by RIA.

Results: After testicular capsulotomy, there was a progressive reduction in the testosterone level in the testicular venous blood together with a progressive increase in the LH and FSH levels in the peripheral blood from approximately 30 days post-capsulotomy.

A functional investigation of tumor suppressor gene activities in a nasopharyngeal carcinoma cell line HONE1 using a monochromosome transfer approach.

Monochromosome transfers of selected chromosomes into a nasopharyngeal carcinoma (NPC) cell line were performed to determine if tumor suppressing activity for NPC mapped to chromosomes 9, 11, and 17. Current information from cytogenetic and molecular allelotyping studies indicate that these chromosomes may harbor potential tumor suppressor genes vital to NPC. The present results show the importance of CDKN2A on chromosome 9 in NPC development.

p53 inactivating mutations in chinese breast carcinomas.

While previous reports on breast cancers indicate that Caucasian women have a low frequency of p53 mutations, higher frequencies of mutations are reported in some Japanese populations. There are few reports regarding p53 mutations in Chinese breast carcinomas. Using a previously established sensitive p53 yeast functional assay, we screened 23 Chinese breast carcinomas for mutations.

Genomic instability and alterations in Apc, Mcc and Dcc in Hong Kong patients with colorectal carcinoma.

Our aim was to reveal the significance of tumor-suppressor genes and genomic instability in 99 Hong Kong Chinese colorectal carcinoma (CRC) patients by PCR-LOH analysis and PCR-PTT assay. The frequencies of allelic loss of Apc, Mcc and Dcc and of APC truncation were 31.3% (15/48), 11.

Measurement of biodegradable substances using the salt-tolerant yeast Arxula adeninivorans for a microbial sensor immobilized with poly(carbamoyl)sulfonate (PCS). Part II: Application of the novel biosensor to real samples from coastal and island regions.

A microbial sensor for rapid measurement of the amount of biodegradable substances based on the salt-tolerant yeast Arxula adeninivorans LS3 has been developed especially for coastal and island regions. Our parameter, the so-called sensorBOD, that is available after only a few minutes, agrees with the 5-day value for the biochemical oxygen demand (BOD5) very well. We have employed the Arxula sensor in the short-time estimation and supervision of the BOD of both domestic and industrial wastewater with high salinity.

Detection of p53 mutations in Hong Kong colorectal carcinomas by conventional PCR-SSCP analysis versus p53 yeast functional assays.

Background: Previous reports indicate that the p53 yeast functional assay is a highly sensitive method of detection of p53 mutations in clinical specimens. Our earlier report (1) showed a 35.4% p53 mutation frequency in Hong Kong colorectal carcinoma (CRC) patients, when conventional molecular screening techniques were utilized to assess the mutation rate in the hot spots in exons 5-8.

Measurement of biodegradable substances using the salt-tolerant yeast Arxula adeninivorans for a microbial sensor immobilized with poly(carbamoyl) sulfonate (PCS) Part I: Construction and characterization of the microbial sensor.

A microbial biosensor based on the yeast Arxula adeninivorans LS3 has been developed for measurement of biodegradable substances. Arxula is immobilized in the hydrogel poly(carbamoyl) sulfonate (PCS). The immobilized yeast membrane is placed in front of an oxygen electrode with -600 mV versus Ag/AgCl.

Ki-ras codon 12 point mutational activation in Hong Kong colorectal carcinoma patients.

This study investigated the frequency and importance of Ki-ras codon 12 mutations in 99 Hong Kong Chinese colorectal carcinoma specimens by allele-specific oligonucleotide hybridization. The frequency of mutations detected was 30% and the most common mutation observed resulted in aspartic acid substitutions. Previous studies showed that specific Ki-ras mutations have been significantly associated with prognosis.

L-myc genotypes in Hong Kong Chinese colorectal carcinoma patients.

L-myc genotypes have been correlated with prognosis in different human tumors. Its role in colorectal carcinoma (CRC) is still unclear. This study aimed to assess the L-myc genotypes in 99 Hong Kong Chinese CRC patients by PCR-RFLP techniques.

p53 inactivating mutations in Chinese nasopharyngeal carcinomas.

Previously a low frequency of p53 mutations was detected in nasopharyngeal carcinoma (NPC) using molecular techniques to screen for mutations, yet immunohistochemical staining revealed a high frequency of p53 aberrant proteins. These findings might be attributed to the occurrence of p53 mutations outside the common hot spots and/or the inactivation of the protein through interactions with cellular or viral proteins. Using a previously established simple and sensitive p53 yeast functional assay, we blindly screened 25 nasopharyngeal biopsies for p53 mutations from exons 4 to 11.

Comparative p53 mutational spectra in aerodigestive tract tumors in Hong Kong Chinese patients.

The p53 mutations in colorectal, esophageal and lung carcinomas from Hong Kong were studied previously. The availability of mutation data for these cancers in one geographical region prompted investigations into special features of these p53 alterations. Mutations in codons 175, 176, 248 and 273 accounted for 35% of all mutations detected.

Autonomic nervous control of venous pressure and secretion in submandibular gland of anesthetized dogs.

In dogs anesthetized with pentobarbital sodium, hilar venous pressure (Phv) and secretion were measured from the submandibular gland receiving spontaneous blood flow or vascular perfusion at the normal resting flow rate. Parasympathetic nerve stimulation and ACh-induced secretion increased Phv and its pulse pressure; Phv also showed an obvious arterial (or perfusion pressure)-like waveform. Vasoactive intestinal polypeptide (VIP) exerted similar effects on Phv but produced negligible secretion.

p53 intron 2 genotypes detected in normal specimens and lung carcinomas in Hong Kong.

Previous studies suggest that the polymorphic p53 intron 2 displays a high frequency of mutations, occurring with different frequencies in tumor tissues versus peripheral blood of lung cancer patients as compared to healthy individuals. We evaluated the significance of these polymorphisms and mutations utilizing matched triple specimens from the lung tumor, normal lung tissue, and peripheral blood of cancer patients. Identical genotypes were observed in normal tissues and blood, while 4 mutations were observed in tumors.

Functional evidence for a nasopharyngeal carcinoma tumor suppressor gene that maps at chromosome 3p21.3.

Nasopharyngeal carcinoma is a malignancy that is prevalent among populations from Southeast Asia. Epidemiological studies indicate that genetic predisposition, Epstein-Barr virus, and environmental conditions may play a role in determining incidence. Molecular studies have implicated a tumor suppressor gene(s) on the short arm of chromosome 3.

p53 mutations detected in colorectal carcinoma patients in Hong Kong.

A mutational spectrum for exons 5-8 of the p53 tumor suppressor gene in colorectal carcinomas in Hong Kong Chinese was established. Ninety-nine colorectal carcinomas from Hong Kong patients were analyzed for mutations in p53 gene by PCR-single-strand conformation polymorphism analysis and direct DNA sequencing. Thirty-five of the 99 tumors (35.

p16 tumor suppressor gene mutations in Chinese esophageal carcinomas in Hong Kong.

The frequency and nature of genetic alterations in the p16 tumor suppressor gene in 25 esophageal squamous cell carcinoma specimens from Chinese patients were investigated by PCR-SSCP and DNA sequencing techniques. No gross deletions occurred in either exon 1 and 2 of the gene by PCR amplification. However, genetic changes were observed in three cases.

The diagnostic value of bronchoalveolar lavage in immunocompetent children with chronic diffuse pulmonary infiltrates.

We have investigated the diagnostic value of (BAL) in 29 immunocompetent children (ages 1 month to 18 years) with chronic diffuse pulmonary infiltrates on chest radiograph who presented for evaluation over a 3-year period. The median age at the time of the BAL was 20 months with a range of 1-210 months. Positive results (1) diagnostic of a primary disorder; (2) consistent with a diagnosis; or (3) diagnostic of a secondary disorder, were obtained in 20/29 patients (13 with a single positive BAL finding and 7 with more than one finding).

Analysis of L-myc and GSTM1 genotypes in Chinese non-small cell lung carcinoma patients.

The genotypes of L-myc and GSTM1 genes were studied in normal lung tissues of 98 non-small cell lung carcinoma (NSCLC) patients from Hong Kong using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) techniques. Results showed a statistical difference in L-myc genotypes between Chinese and African Americans (P = 0.02).

Tissue distribution of Epstein-Barr virus genotypes.

The genome of naturally occurring Epstein-Barr virus contains either two or three copies of a 29-bp tandem repeat sequence in the first intron of the BZLF gene. These genotypes differ markedly in their distribution between blood and epithelial tissues, presumably because they have adapted to separate life cycles in these sites. The genotype prevalent in the blood also appears to be better able to transform B lymphocytes.

Chromosomal 11 alterations in non-small-cell lung carcinomas in Hong Kong.

We examined 60 non-small-cell lung cancer (NSCLC) patients for evidence of genetic alterations on chromosome 11 with nine polymorphic markers by Southern blot and microsatellite marker analysis. These analyses detected genetic alterations at both the 11p and 11q arms. At the 11p15 Ha-ras locus, the loss of heterozygosity (LOH) occurred in three out of 11 (27.

Detection and evaluation of p53 intron 2 polymorphism in lung carcinomas in Hong Kong.

A polymorphism in intron 2 of the p53 gene, which gives rise to 2 alleles, A1 and A2, was analyzed by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct DNA-sequencing techniques. The distribution of this allele in the peripheral blood in the Chinese population comprising 27 healthy individuals, 30 bronchiectasis patients, 34 non-small-cell lung cancer (NSCLC) patients and 27 SCLC patients was analyzed. The genotypic distributions for this marker were significantly different between the blood of healthy individuals and SCLC patients.

p53 mutational spectrum of esophageal carcinomas from five different geographical locales in China.

A mutational spectrum for exons 5-8 of the p53 tumor suppressor gene in esophageal carcinomas in mainland China and Hong Kong was established. This study involved 209 squamous cell carcinoma specimens obtained from five different geographical locales in China: Zhengzhou, Taiyuan, Shantou, Guangzhou, and Hong Kong. Zhengzhou and Shantou were high-incidence regions for esophageal cancer, whereas the other three regions had low or intermediate incidence of the disease.

p53 mutations in non-small cell lung carcinomas in Hong Kong.

Lung resections from 50 Chinese patients in Hong Kong diagnosed as having non-small cell lung carcinoma were examined for the presence of mutations in the p53 gene by polymerase chain reaction single-stranded conformation polymorphism methods and for aberrant protein expression by immunostaining techniques. Eight-point mutations in the evolutionarily conserved exon 5 through 8 regions were detected. Abnormal expression of p53 detectable by immunostaining techniques was seen in 23 specimens tested.

Pulmonary vascular disorders masquerading as interstitial lung disease.

During the acquisition of a series of 92 children with interstitial lung disease (ILD) over a 14 year period, a significant minority (8/92 or 9%) were initially diagnosed as having ILD, but were subsequently found to have a variety of arterial, venous, and/or capillary disorders that explained their initial pulmonary findings. This subgroup of patients has had a very high morbidity and mortality, with only three of eight patients currently surviving. The presentation, evaluation, and natural history of these eight children were reviewed.