A Cross-cultural Study of Alcohol Dependence in Singapore

This is a comparative study of alcohol dependence in Chinese and Indian patients admitted to a hospital in Singapore. There were 46 patients-21 Chinese and 35 Indians. In both ethnic groups there was a preponderance of male over female patients. There was no significant difference in the mean ages of the two groups but Indian patients started drinking at an earlier age and more of them had a family history of alcohol problems. Comparing the severity of alcohol dependence, Indian patients scored higher on the SADQ but no patients scored above 30 points.     

Histopathologic studies of the liver following intravenous colloidal 198Au therapy

Histologic studies of liver tissue from 27 patients given up to 395 mCi (cumulative) of intravenous colloidal 198Au showed no definite radiation injury and no correlation between hepatic abnormalities and dose. Demonstration of aggregates of colloidal gold in the Kupffer cells was inconsistent, suggesting slow removal or dispersion. Although the liver ordinarily receives the highest radiation dose, the critical organ is the marrow. Results support the recent introduction of 198Au to supplement teletherapy for certain neoplasms diffusely infiltrating the liver. Apparently the beta distribution minimizes endothelial injury in large vessels, which has been shown to be the cause of radiation hepatitis.     

The window for embryo transfer in oocyte donation cycles depends on the duration of progesterone therapy

In 192 oocyte donation cycles performed between January 1993 and July 1996, we examined the width of 'the window for embryo transfer' using standard hormonal replacement methods. All transfers were performed within 48 h of insemination. We varied the day of embryo transfer with regard to the initiation of progesterone therapy and, thus, the duration of endometrial exposure to progesterone and analysed the resulting pregnancy rates. Patients were divided into five groups (I-V) and embryo transfers were performed 2, 3, 4, 5 or 6 days following initiation of progesterone therapy. The number of pregnancies per transfer cycle achieved in groups I-V were 0 (0%), 3 (12%), 16 (40%), 29 (48.3%), and 10 (20.4%) respectively. The increased pregnancy rate in group III in comparison to group II is statistically significant (P < 0.03). Furthermore, the pregnancy rate in group IV (5 days of progesterone administration before embryo transfer) was significantly higher than in group V (6 days of progesterone administration before embryo transfer; P < 0.005). We also noted that, when embryos were transferred 4 or 5 days after initiation of progesterone therapy, the pregnancy rates were not significantly different between menopausal and cycling recipients (50% vs 43.7%). Our results indicate that the window for embryo transfer is dependent on duration of treatment with progesterone; it begins approximately 48 h after starting progesterone administration and lasts for approximately 4 days. The optimum period for transferring embryos at the 4- to 8-cell stage corresponds to cycle days 18 and 19. Transfers performed on the 17th and 20th days of the cycle can result in successful implantation, although the rates of implantation are highest when transfers are done on days 18 and 19.      

The effect of skin transplantation on tumor growth in mice

BACKGROUND: Skin allograft is an immunostimulant. Skin allograft activates effector arms of the immune system including the cytotoxic T lymphocytes, activated macrophages, and natural killer cells. These cells may be involved in the destruction of tumor cells. METHODS: Balb/c mice were divided into the study (n = 10) and control (n = 10) groups. Alloskin grafts 1 cm in diameter from the backs of Swiss albino mice were placed on the backs of balb/c mice (study group). The same size autoskin grafts from the backs of other balb/c mice were used for the control group. Fourteen days after grafting, we inoculated 1,000 Ehrlich ascites tumor cells intraperitoneally into both groups. Two days after tumor inoculation, we used secondary allografts and autografts (which were about 2 to 3 mm in diameter) for the same groups. We followed up graft survival and animal survival in both groups. RESULTS: All 10 of the autografted mice died between the 18th and 25th days owing to malignancy. In the allografted group, 2 mice died (1 on day 17 and the other on day 23). Allograft rejection had not occurred in these 2 mice at the time of their death. The other 8 mice in the same group rejected allograft, on average within 9 days (9+/-3, median 8). These 8 mice were alive and without apparent health problems during the 4 months of follow-up. CONCLUSION: Allo-skin graft rejection may help rejection of tumor cells and may be of use in immunotherapy of cancer.     

Preparation and properties of alpha-galactosidase chemically attached to activated chitin

alpha-Galactosidase (alpha-D-galactoside galactohydrolase, EC 3.2.1.22) from watermelon was covalently immobilized on chitin. The immobilized alpha-galactosidase exhibited an activity of 0.61 U per g of carrier and an activity yield of 67%. The properties of free and immobilized alpha-galactosidase were also searched and compared. The results showed that, optimum conditions for activity were not affected by immobilization. The optimum pH and temperature for free and immobilized enzyme found as pH 6.0 and 65 degress C, respectively. Compared with the free enzyme, the temperature and pH stabilities of the immobilized enzyme were similar. Both the enzymes were stable between pH 2-10 and below 50 degrees C. The Km values for free and immobilized enzyme were determined using p-nitrophenyl-alpha-D-galactopyranoside (PNPG) and raffinose as substrates. Operational stability of the immobilized enzyme was investigated by using both substrates. The operational half-life (t 1/2) was calculated as 34 h for PNPG and 28 h for raffinose. The immobilized alpha-galactosidase was also utilized in the hydrolysis of raffinose. The immobilization procedure on chitin was cheap and also easy to carry out, and the immobilized enzyme had good properties that the potential for practical application is considerable.     

The impact of air pockets around the vaginal cylinder on vaginal vault brachytherapy

Objective:

To evaluate the incidence, size and predisposing factors for air pockets around the vaginal cylinder and their dosimetric effect on the vaginal mucosa.

Methods:

We investigated 174 patients with endometrial carcinoma treated with external radiotherapy (RT) and brachytherapy (BRT) (101 patients, 58%) or BRT alone (73 patients, 42%). The quantity, volume and dosimetric impact of the air pockets surrounding the vaginal cylinder were quantified. The proportions of patients with or without air pockets during application were stratified according to menopausal status, treatment modality and interval between surgery and RT.

Results:

Air pockets around the vaginal cylinder were seen in 75 patients (43%), while 99 patients (57%) had no air pockets. Only 11 patients (6.3%) received less than the prescribed dose (average 93.9% of prescribed dose; range, 79.0–99.2%). Air pockets were significantly fewer in pre-menopausal patients or in patients treated with the combination of external RT and BRT than in post-menopausal patients or patients treated with BRT alone. A significant correlation existed between the mucosal displacement of the air gap and the ratio of the measured dose at the surface of the air gap and prescribed dose (Pearson r = −0.775; p < 0.001).

Conclusion:

Air pockets were still a frequent problem during vaginal vault BRT, especially in post-menopausal patients or in patients treated with BRT alone, which may potentially cause dose reductions at the vaginal mucosa.

Advances in knowledge:

Air pockets around the vaginal cylinder remain a significant problem, which may potentially cause dose reduction in the target volume.The primary treatment of choice in localized endometrial cancer is surgery. Adjuvant radiotherapy (RT) is recommended in intermediate- and high-risk patients in order to diminish disease recurrence. RT can be in the form of external RT (ERT) with vaginal vault brachytherapy (BRT) or BRT only, depending on the risk factors and stage of disease.The purpose of vaginal vault BRT is to eradicate a microscopic tumour at the lymphatics located in the vaginal vault. It was demonstrated that >90% of lymphatics lie within 2–3 mm from the surface of stretched mucosa.¹ For this reason, in order to deliver adequate doses to the submucosal lymphatics, the vaginal cylinder must be in direct contact with the vaginal surface, as recommended by the American Brachytherapy Society (ABS).² The Group Europeén de Curiethérapie and the European Society for Radiotherapy & Oncology (GEC-ESTRO) guidance³ is to prescribe vaginal BRT to 5 mm from the applicator surface with a 2-mm tolerance. The most commonly used applicator for vaginal vault high-dose-rate BRT is a segmented cylinder.⁴ However, during application, air gaps may be observed, which may potentially cause underdosage of the vaginal mucosa.Cameron et al⁵ found that 18 of 25 patients (72%) had air gaps >2 mm in the cranial part of the vagina, with the median number of air pockets per patient being 1 (range, 0–5). Richardson et al⁶ reported that 20 of 25 patients (80%) had at least 1 air pocket in the upper vagina. In another study, Humphrey et al⁷ demonstrated >2 mm air gaps in 11/103 patients, while repositioning or use of a larger cylinder reduced air gaps in 7/103 patients. However, in all of these studies, applicators of different sizes were used with a limited number of patients and conflicting results have been reported.In Baskent University Department of Radiation Oncology, Adana, Turkey, we prefer using cylinders with the largest diameter for reducing air gaps during vaginal vault BRT. The purpose of this study was to evaluate the incidence, size and dosimetric effects of these air pockets. In addition, the predisposing factors for the development of air gaps were analysed.     

The effect of androgen deprivation therapy on 68 Ga-PSMA tracer uptake in non-metastatic prostate cancer patients

To evaluate the effect of neoadjuvant androgen deprivation treatment (ADT) on prostate-specific membrane antigen (PSMA) tracer uptake demonstrated in 68Ga-PSMA-positron emission tomography (PET/CT) in non-metastatic hormone-naïve prostate cancer (PC) patients. The clinical data of 108 PC patients who received neoadjuvant ADT were retrospectively analyzed. All patients had a baseline 68Ga-PSMA-PET/CT scan, and a second scan was delivered median of 2.9 months after the initiation of ADT. The maximum standardized uptake value (SUVmax) of primary tumor (SUVp) and metastatic lymph nodes (SUVln) as well as PSA response were assessed between pre- and post-ADT 68Ga-PSMA-PET/CT scans. There were significant decreases in posttreatment serum PSA, SUVp, and SUVln. A decrease in SUVp was seen in 91 patients (84%) with a median value of 66% (range, 5–100%), while 17 patients (16%) had no change in or an increase in PSMA tracer uptake with a median value of 24% (range, 0–198%). Patients with Gleason score (GS) of 7 had significantly higher metabolic response rates compared to other patients. The disease progression was significantly higher only in patients with GS > 7 disease compared to GS 7 disease. The PSA response to ADT was the lowest in patients with ISUP high-grade tumors. A total of 16 patients (15%) had progressive disease, and in 9 patients (8%), radiotherapy decisions were modified according to posttreatment 68Ga-PSMA-PET/CT scans. The current study includes the largest number of patients analyzed to date and demonstrates that ADT causes a significant decrease in serum PSA values and SUVp and SUVln. The authors demonstrate that 68Ga-PSMA-PET/CT may be used as a quantitative imaging modality after neoadjuvant ADT in hormone-naïve non-metastatic PC patients.     

Evaluation of Factor V Leiden,Prothrombin G20210A,MTHFR C677T and MTHFR A1298C gene polymorphisms in retinopathy of prematurity in a Turkish cohort

Background: To assess Factor V Leiden (FVL) (rs6025), Prothrombin G20210A (rs1799963), MTHFR C677T (rs1801133), and MTHFR A1298C (rs1801131) gene mutations as risk factors in the development of retinopathy of prematurity (ROP).

Materials and methods: A total of 105 children were included in this cross-sectional study. Patients were divided into two groups. The study group consisted of 55 infants with a history of ROP and the control group comprised 50 healthy infants with term birth. All subjects were screened for the presence of certain mutations (FVL, Prothrombin G20210A, MTHFR C677T and MTHFR A1298C) by Real-Time PCR at 1 year of age.

Results: The mean gestational age (GA) and birth weight (BW) of the study group were, 28.65 ± 2.85 weeks and 1171 ± 385.74 g, respectively. There were no significant differences of genotype and allele frequency of Prothrombin G20210A, MTHFR A1298C and MTHFR C677T between the study and control groups (p > 0.05). Eight children (14.5 %) had heterozygous and one child (1.8%) had homozygous FVL mutation in the study group. One child (2%) in the control group had heterozygous FVL mutation. There was statistically significant differences of FVL allele and genotype frequencies between the groups (p < 0.05).

Conclusions: The prevalence of FVL polymorphism (16.3 %) was higher in ROP patients than control subjects in this Turkish cohort. We suggest a possible association of FVL mutation with ROP at the end of the study.