Sy Chan

Predictive value of sperm morphology and movement characteristics in the outcome of in vitro fertilization of human oocytes

One hundred fourteen semen samples from Chinese males were analyzed for routine semen parameters including the semen volume, sperm count, percentage motility, and percentage normal morphology. Of these 114 samples, 54 also had movement characteristics of seminal and swim-up sperm evaluated by the computer image analyzer system (Cellsoft; Cryo Resources Co., New York). All semen samples were subjected to the swim-up procedure to harvest the motile sperm before inseminations of human oocytes. Fertilization was considered to have occurred when at least one oocyte was observed with two or more pronuclei. Semen samples were classified as infertile (0% fertilization rate;N=32) or fertile (>0% fertilization rate;N=82) before statistical analyses. There was a significant difference (P<0.005) in percentage normal morphology of seminal sperm between the fertile (mean±SE; 67.3±1.2%) and the infertile (59.3±2.2%) samples. The percentage normal morphology of seminal sperm correlated (r=0.3049;P<0.002) with the fertilization rate and this parameter was selected by the multivariate stepwise discriminant analysis as the discriminator capable of predicting the fertilization rate with 57.9% accuracy. Statistical analyses of samples where sperm movement was also evaluated demonstrated that there was significant differences (P<0.01) between the fertile (N=38) and the infertile (N=16) samples in percentage normal morphology of seminal sperm (67.8±1.8% vs 56.2±2.6%) and curvilinear velocity of swim-up sperm (89.2±3.5 vs 68.2±7.2 μm/sec). The fertilization rates correlated with the percentage normal morphology of seminal sperm (r=0.3868;P<0.005) and velocity of swim-up sperm (r=0.3842;P<0.005). Multivariate stepwise discriminant analysis demonstrated that these two sperm parameters in combination were capable of predicting the fertilization rate with 74.1% accuracy. Our results indicate that seminal sperm morphology, coupled with computerassisted image analysis of movement characteristics of swim-up sperm, can help to predict the outcome of in vitro fertilization of human oocytes.

Colorectal carcinoma in Hong Kong: epidemiology and genetic mutations

The incidence of colorectal carcinoma is rising at an alarming pace in Asian urban societies such as Hong Kong. Detailed examination of the epidemiological pattern and genetic mutation of colorectal cancer in the Hong Kong Chinese population is overdue. We compared the reported age incidence of colorectal carcinoma in Hong Kong with that of Scotland and other countries. Hong Kong showed a much higher incidence of colorectal carcinoma among the young age groups. By comparison with other countries, this raised incidence among the young appeared to be related to southern Chinese societies. The recent dramatic rise in colorectal cancer in Hong Kong was largely attributable to an increase in the over 50 years age group, while the young incidence remained unchanged. We also defined the mutation spectrum of p53 and Ki-ras in 67 unselected cases by direct DNA sequencing. Interestingly, insertion/deletion mutations in p53 from colorectal carcinoma in Hong Kong showed a significantly higher frequency (17.2%) than the Scottish data (0%) and the world database (6.6%), although the overall frequency of p53 mutation (43%) in Hong Kong was similar to others. The high incidence of colorectal carcinoma in young people and the raised proportion of frameshift mutations in p53 encourage further search for a genetic basis for susceptibility to this disease in the Hong Kong Chinese population.

Serum squamous cell carcinoma antigen in the monitoring of radiotherapy treatment response in carcinoma of the cervix

In this study, squamous cell carcinoma antigen (SCC) was detected in 96 of 157 patients with squamous cell carcinoma of the cervix and the percentage of patients with raised SCC levels increased with the stage of disease (P less than 0.01). The use of serial SCC assays and cervical biopsy histology during the course of radiotherapy to predict tumor response to irradiation was assessed. In patients who were given external irradiation before intracavitary radium, a high SCC level or the presence of viable tumor cells in the biopsy was found to be of no predictive value. However, at completion of radiotherapy, i.e., after intracavitary radium application, patients with persistently high SCC levels had a significantly higher incidence of residual tumor than patients whose SCC levels returned to normal (P less than 0.01). In 60% of patients with a persistently high SCC level, viable tumor was found in the cervical biopsy at the end of radiotherapy. On the other hand, only 5.4% of patients whose SCC level returned to normal had residual tumor.

Primary mixed neuroendocrine and mucinous carcinoma of the ovary

SummaryA rare case of mixed carcinoma of ovary with a predominant malignant neuroendocrine and a lesser mucinous tumor component is described. Extensive areas of enteric-type epithelium containing endocrine cells were present in both the mucinous borderline tumor element and in the small foci of mucinous adenocarcinoma. Transition from the mucinous tumor to the malignant neuroendocrine component provides evidence for the derivation of some neuroendocrine or carcinoid tumors direct from mucinous tumors without necessarily being a component of a teratoma. Contrary to reported examples of mucinous carcinoid, the overgrowth and spread of the neuroendocrine component characterised the aggressive and lethal nature of this tumor.

Use of serum squamous cell carcinoma antigen assays in chemotherapy treatment of cervical cancer

Serum squamous cell carcinoma antigen levels of 15 patients with recurrent or progressive squamous cell carcinoma of the cervix on chemotherapy treatment were assayed. In 13 of these 15 patients (86.7%), clinical response was positive correlated with change in serum SCC level. A stationary or rising serum SCC level indicated that the disease is probably stationary or progressive and chemotherapy should be stopped or changed.

Up-regulation of lysozyme production in colonic adenomas and adenocarcinomas.

The presence of lysozyme protein in some gastric adenomas and adenocarcinomas has been well documented. There have been relatively few studies investigating the presence of lysozyme in tumours of the large intestine and they show contrasting results. We aim to investigate the cellular source and expression of lysozyme in colonic adenomas and adenocarcinomas.

Spermatozoal Fertilizing Capacity in Polyzoospermia: a Preliminary Study

Summary:  Men with the spermatological symptom of polyzoospermia (> 250 times 106 sperm/ml) have been reported to seldom impregnate their wives. It was the aim of this study to investigate the spermatozoal fertilizing capacity in polyzoospermia by the human sperm and zona‐free hamster ova penetration bioassay. General semen characteristics and in vitro spermatozoal fertilizing capacity were studied in 12 polyzoospermic male partners of couples of infertile marriages. The results were compared with those from a control group of normospermic fertile men (n = 22). No significant differences in sperm motility, normal morphology and in vitro spermatozoal fertilizing capacity were found between the two groups. The polyzoospermic men we studied did not appear to have any defect with the spermatozoal fertilizing capacity, as assessed by the heterologous sperm ‐ ova penetration bioassay. The apparent impairment of fertility and higher abortion rate in couples with polyzoospermic male partners, as described in the literature, may be related to chromosomal aberrations and/or other unknown functional defect of the spermatozoa.

Association of time to prostate-specific antigen nadir and logarithm of prostate-specific antigen velocity after progression in metastatic prostate cancer with prior primary androgen deprivation therapy.

We investigated the association of time to prostate-specific antigen nadir (TTPN) and logarithm of prostate-specific antigen velocity after progression Log(PSAVAP) in metastatic prostate cancer with prior primary androgen deprivation therapy (ADT). All metastatic prostate cancer patients treated with primary ADT from 2000 to 2009 were reviewed. Patients who developed disease progression were included in the subsequent analyses. Patients were categorized into three groups according to their TTPN: TTPN of <3 months, 3-17 months, and >17 months. We compared the Log(PSAVAP) between the different TTPN groups using Mann-Whitney U-test and Kruskal-Wallis test. Further multiple linear regression analyses on Log(PSAVAP) were performed to adjust for other potential confounding factors. Among 419 patients who were treated with primary ADT, 306 patients developed disease progression with a median follow-up of 28 months. Longer TTPN was associated with lower Log(PSAVAP) (P = 0.008) within all subgroup analyses (TTPN of <3 vs 3-17 months, P= 0.020; TTPN of 3-17 vs >17 months, P= 0.009; and TTPN of <3 vs >17 months, P= 0.001). Upon multiple linear regression analyses, baseline PSA (regression coefficient 0.001, P= 0.045), PSA nadir (regression coefficient 0.002, P= 0.040), and TTPN (regression coefficient −0.030, P= 0.001) were the three factors that were significantly associated with Log(PSAVAP). In conclusion, a longer TTPN was associated with lower Log(PSAVAP) in metastatic prostate cancer patients following primary ADT. TTPN cut-offs at 3 months and 17 months appeared to have prognostic significance in predicting Log(PSAVAP). TTPN may serve as a good prognostic indicator in deciding the treatment strategy in patients with disease progression.

Gastric conduit failure after esophagectomy: acute management and surgical reconstruction options

Background: Brazilian population presents very high levels of genomic diversity due to the multi-ethnicity, which have important clinical/genomic implications. Cyclooxygenase-2 (Cox-2) is induced in response to growth factors and cytokines; and is expressed in infl ammatory diseases, premalignant and esophageal tumors. The product of folate metabolism by the enzyme methylenetetrahydrofolate reductase (MTHFR) acts in DNA synthesis. Alteration or inhibition of this enzyme increases the susceptibility to mutations, alter DNA methylation, and gene expression of the tumor suppressor genes and proto-oncogenes, leading to a potential risk factors for esophageal cancer. Cox-2 and MTHFR polymorphisms might modify the levels of protein expression and may have a considerable infl uence on disease phenotype, which may have important clinical/genomic implications.