Epidemiology and risk factors of Alzheimer's disease

The epidemiology of Alzheimer's disease is complex. The approach of the distribution of this disease in human populations is limited by an insidious onset and a difficult diagnosis assessment for alive patients. The hunt for Alzheimer's disease determinants has been boosted by the development of molecular biology techniques, allowing the detection of genetic susceptibility factors. Epidemiology offers new areas of research in the field of a disease whose impact and severity is growing, but whose preventive and therapeutic issues remains uncertain.     

Epidemiology and risk factors of wedge-shaped defects in a Swiss population

The purpose of this study was to determine the prevalence of wedge-shaped abrasion defects in the teeth of an adult Swiss population. 980 letters explaining the study were sent to randomly selected subjects. 391 persons (40%) belonging to two age groups (26-30 and 46-50 years) were checked for frequency and severity of wedge-shaped lesions on all buccal tooth surfaces. Furthermore patients were asked about dietary and prophylactic habits as well as other factors possibly relevant to this study. The frequency of severe wedge-shaped defects was 19.1% in the younger, and 47.2% in the older age group, with a mean of 3 affected teeth per person (pooled age group). On average, 34.8% of all patients suffered from tooth hypersensitivity. 84.6% of the examinees with wedge-shaped defects complained of hypersensitivity at these sites. It is concluded that wedge-shaped defects cause considerable problems to more than one third of the population, and that such lesions are often combined with hypersensitivity of affected teeth.     

Epidemiology, risk factors and prophylaxis of venous thrombo-embolism in obstetrics and gynaecology

The classical psychoanalytic concept of the one-person treatment model and its assumptions concerning psychic reality are compared with the contemporary two-person model, subsumed under the concept of "alterity" (otherness). The classical model of unconscious mental life is explored in terms of the principles of "autochthony" (signifying the fantasy that self and object are created entirely from and by the self) and "cosmogony" (an aspect of primary and secondary processes that accounts for the creation of a personal and an objective world-view). Autochthony and cosmogony are subsumed under the category of "creationism." I discuss why I identify these three phenomena by these relatively unused terms.     

Dietary factors and the risk of endometrial cancer

BACKGROUND: Endometrial cancer is associated with overweight, but little is known on its possible relationship with specific aspects of diet. METHODS: The relationship between dietary factors and the risk of endometrial cancer was investigated in a case-control study conducted in Switzerland and Northern Italy on 274 patients with histologically confirmed endometrial cancers and 572 control subjects admitted to the hospital for acute nongynecologic disorders that were not hormone related, metabolic, or neoplastic. RESULTS: Significant direct associations were observed with (1) the total energy intake (odds ratio [OR] for the highest versus the lowest consumption tertile = 2.7) and, after allowance for energy intake, (2) the frequency of consumption of most types of meats, eggs, beans or peas, added fats (OR for total added fat = 2.5), and sugar (OR = 2.5). Significant protection, of the order of 40-60% reduction in the highest versus the lowest consumption tertile, was conferred by elevated intake of most vegetables and fresh fruit and whole grain bread and pasta. This was reflected in the low OR for the highest tertiles of intake of beta-carotene and ascorbic acid (OR for the highest versus the lowest consumption tertile after allowance for energy intake = 0.5). CONCLUSIONS: The current study suggests that, aside from the predictable adverse effects of overeating and consequent overweight, some qualitative aspects of the habitual diet may also be associated with the risk of endometrial cancer, chiefly, the intake of animal proteins and fat (directly) and of fresh fruit, vegetables, and fibers (inversely).     

Postoperative radiation for cervical cancer with pathologic risk factors

PURPOSE: To examine the efficacy of postoperative radiation therapy for early-stage cervical cancer with pathologic risk factors. METHODS AND MATERIALS: We reviewed the charts of 83 patients who received postoperative radiation therapy at our facility from March 1980 to November 1993 for early stage cervix cancer with positive surgical margins, positive pelvic or periaortic lymph nodes, lymphovascular space invasion, deep invasion, or for disease discovered incidently at simple hysterectomy. Twenty-eight patients received low dose rate (LDR) intracavitary radiation with or without external beam pelvic irradiation and 55 patients received external beam pelvic irradiation with high dose rate (HDR) intracavitary implants. Of these 83 patients, 66 were evaluable--20 LDR and 46 HDR patients. All patients received 45-50 Gy external beam irradiation and 20 Gy LDR equivalent intracavitary irradiation prescribed to 0.5 cm below the mucosa. Ninety percent of the LDR group and 92% of the HDR group completed treatment within < 56 days. Treatment-related toxicities were scored according to the GOG toxicity scale. Mean and median follow-up times were 101 months and 111 months (3-172 months) for the LDR group and 42 and 40 months (3-98 months) for the HDR group. RESULTS: The 5-year disease-free survival was 89% for the LDR group and 72% for the HDR group. Local control was observed in 90% (18 out of 20) of the LDR patients and 89% (41 out of 46) of the HDR patients for an overall local control rate of 89.5%. Two of 20 LDR patients (10%) experienced recurrence (two pelvic with distant metastasis). Nine of 46 HDR patients (22%) had recurrence of disease (three pelvic, four distant metastasis, and two pelvic with distant metastasis). In the HDR group, 6 out of 16 (38%) with positive lymph nodes died of disease whereas, 27 out of 30 (90%) of the patients with negative lymph nodes remain free of disease. Three of 20 (15%) LDR patients and 4 out of 46 (9%) HDR patients experienced Grade 2 or 3 late treatment- related complications. No patient in either group had Grade 4 or 5 complications. Pathologic risk factors were analyzed. Lymph node positivity and lymphovascular space invasion were found to be significant (p = 0.01 and p = 0.02). Positive margins, deep invasion, and age were not significant. CONCLUSION: Our results demonstrate the efficacy of postoperative irradiation for cervical cancer with pathologic risk factors. Overall, the local control rate was 89.5% The HDR results demonstrate that this method can be delivered safely and effectively.     

Inherited factors and environmental exposures in cancer risk

Carcinogenesis is a multistage process that results from the interaction of carcinogenic exposures, cellular macromolecules (eg, DNA), and endogenous mutational mechanisms. Involved in these processes are metabolic activation and detoxification of chemical carcinogens, genetic sequences of protooncogenes and tumor suppressor genes, and DNA repair, among others. Each of these vary widely among individuals and can be associated with increased cancer risk. Cytochrome P4501A1, P4502E1 and N-acetyl transferase 2 are examples of enzymes involved in the metabolic activation of potential environmental carcinogens such as polycyclic aromatic hydrocarbons, benzene, and aromatic amines, respectively. Germ-line mutations in these genes are common and associated with abnormal enzymatic function that are mechanistically related to quantitative changes in binding of carcinogens to DNA. Allelic frequencies for these mutations vary among different racial and ethnic populations and may explain, in part, differences in cancer rates. Risk assessments attempt to predict cancer rates in humans using mathematical models that are often based upon limited experimental data. They do not generally incorporate the numerous stages of carcinogenesis or interindividual variation. Thus, sensitive and resistant populations are not sufficiently considered. This limits the accuracy of currently applied risk assessment models.     

Dietary factors and risk of lung cancer in never-smokers

The primary purpose of this study was to evaluate the effectiveness of cortical anchorage, by comparing two groups of patients with Class II malocclusions that were treated successfully with Class II elastics. One group of 30 previously treated patients had a utility arch used to set up cortical anchorage in the lower arch before Class II elastic wear; the second group was treated with standard edgewise mechanics where anchorage preparation consisted of full appliances, a well-aligned mandibular arch, and a rectangular arch wire. The groups were selected according to age, sex, and the amount of Class II elastic usage. Pretreatment and posttreatment cephalometric radiographs were used to generate 32 variables. A Student's t test was used to evaluate treatment change between the groups and revealed that there were no statistically significant differences. Lower molar teeth extruded and moved mesially equally in both groups. Although cortical anchorage did not retard lower molar movement, it was no less effective in controlling molar movement with a partial appliance than the fully banded standard edgewise appliance.     

Dietary risk factors for colon cancer in a low-risk population

Spontaneous EEG was registered under different activity conditions in 26 volunteers. The EEG synchronisation parameters were compared with the geomagnetic and solar activity on the day of experiment. A positive correlation of the EEG data with the geomagnetic activity was revealed, being most obvious in the frontal and central areas. A negative correlation between some local EEG synchronisation parameters and different indices of the solar activity, was also revealed. The degree of synchronisation of the spontaneous EEG seems to reflect sensitivity of the human nervous system to the Earth's magnetic field. A stressor response to strong short-term disturbances in the geomagnetic field reveals itself in the form of enhancement of the EEG global synchronisation. A sedative effect of slow magnetic oscillations is locally revealed in the parameters of the EEG synchronisation within the left hemisphere as well as the interhemisphere synchronisation.     

Epidemiology of congenital cytomegalovirus infection: maternal risk factors and molecular analysis of cytomegalovirus strains

To determine factors that influence the occurrence of congenital cytomegalovirus (CMV) infection, the authors surveyed prospectively 8,254 infants born in eastern Iowa between October 1989 and June 1994. The authors conducted a case-control study to identify maternal risk factors, matching each CMV-infected infant with three uninfected infants according to hospital and date of birth. CMV strains were compared by using the polymerase chain reaction (PCR) to identify common sources of infection. Of the 7,229 infants cultured successfully for CMV, 35 (0.48%) were congenitally infected. Mothers of CMV-infected infants were more likely to be single (odds ratio (OR) = 3.05, p = 0.016), to work in sales (OR = 4.93, p = 0.008), or to be students (OR = 5.01, p = 0.017). Conversely, women who worked in health-care professions were less likely to have a congenitally infected infant (OR = 0.14, p = 0.049). PCR analysis indicated 27 distinct strains of CMV, but two groups of infants (two infants per group) excreted strains with indistinguishable molecular patterns. One of these pairs of infants had older siblings who attended the same child-care center during their mothers' pregnancies. The authors concluded that demographic and occupational factors influenced the risk of giving birth to an infant with congenital CMV infection. Many distinct CMV strains were identified, suggesting that major point source outbreaks had not occurred. Nonetheless, point source acquisition of CMV from child-care environments did account for some cases of congenital CMV infection in eastern Iowa.     

Anthropometric and other risk factors for ovarian cancer in a case-control study

Because it has been suggested that an environmental factor may play a role in the etiology of ovarian cancer, a case-control study was conducted to assess some environmental and other risk factors for ovarian cancer from 1994 to 1996 in northern Kyushu, Japan. We analyzed the data of 89 cases with epithelial ovarian cancer and 323 controls without any cancer or ovarian disorder. After controlling for the effect of potential confounders, the odds ratios of ovarian cancer across increasing quartiles of the heaviest body weight were 1.00, 1.15, 1.71, 2.29 (P = 0.008, test for trend). Significantly increased risks were noted for a history of diabetes mellitus (P < 0.05), and for a family history of ovarian cancer (P < 0.05). Significantly decreased trends for risk were obtained for the number of pregnancies (P < 0.01) and the number of live births (P < 0.001). This study provides additional support for an association between obesity and the risk of ovarian cancer. This relationship may at least partly explain the recent increase in the incidence of ovarian cancer in Japan, although possible contributions of other factors can not be ruled out.     

中国东北地区成人非传染性慢性疾病的流行病学调查及影响因素分析

目的:了解中国东北吉林省德惠市城乡居民高血压、糖尿病(DM)、血脂紊乱、酒精性肝病(ALD)、非酒精性脂肪性肝病(NAFLD)、代谢综合征(MS)及肥胖(Obesity)等9种非传染性慢性疾病的流行病学现状,并对这些慢性病危险因素进行分析.方法:采用分层抽样方法,对德惠市11个居委会和9个村共6 043人进行问卷调查和体格检查.采用多因素Logistic回归分析对各疾病的相关危险因素进行分析.结果:东北地区德惠城乡居民的高血压、DM、血脂紊乱、ALD、NAFLD、MS、超重和中心型肥胖的患病率分别为28.67%、4.82%、51.00%、3.74%、15.5%、21.54%、58.22%和36.67%;不同疾病患病率性别间比较有差异,高血压患病率男性多于女性(P<0.001),中心性肥胖、血脂紊乱、MS和NAFLD患病率女性大于男性(P<0.05).高龄(OR=1.04,95%CI为1.03～1.05)、脂肪肝(OR=19.42,95%CI为11.62～32.4)、高血糖(OR=1.15,95%CI为1.06～1.26)、高胆固醇血症(OR=1.38,95%CI为1.19～1.59)、高甘油三酯血症(OR=1.32,95%CI为1.1～1.49)和高体重指数(OR=1.42,95%CI为1.3～1.47)是非传染性慢性病的主要危险因素.结论:中国东北部地区德惠市部分非传染性慢性病的发病率较高,且随着年龄的增长患病率逐渐增高;慢性病的发病和进展与本地区的生活、饮食习惯、经济水平、教育程度、地区差异有明显相关性.     

Parity and the risk of pancreatic cancer: a nested case-control study

Three unusual cases of small-size leiomyosarcoma of the perirenal space were studied with CT. The renal capsule has been proved to be the origin of this type of tumor. A CT examination is accurate in suggesting the site of origin and excluding a renal cell carcinoma. However, unless evidence of invasion is noted, it is impossible on CT features to discriminate leiomyosarcoma from a benign leiomyoma.     

Long-term impact of reproductive factors on cancer risk

In the program ODS we provide a methodology for quickly ordering random clones into a physical map. The process of ordering individual clones with respect to their position along a chromosome is based on the similarity of binary signatures assigned to each clone. This binary signature is obtained by hybridizing each clone to a panel of oligonucleotide probes. By using the fact that the amount of overlap between any two clones is reflected in the similarity of their binary signatures, it is possible to reconstruct a chromosome by minimizing the sum of linking distances between an ordered sequence of clones. Unlike other programs for physical mapping, ODS is very general in the types of data that can be utilized for chromosome reconstruction. Any trait that can be scored in a presence--absence manner, such as hybridized synthetic oligonucleotides, restriction endonuclease recognition sites or single copy landmarks, can be used for analysis. Furthermore, the computational requirements for the construction of large physical maps can be measured in a matter of hours on work-stations such as the VAX2000.     

Analysis of risk factors for cisplatin-induced ototoxicity in patients with testicular cancer

This study evaluates the degree and relevance of persisting ototoxicity after cisplatin-based standard-dose chemotherapy for testicular cancer, with emphasis on identification of potential factors for an increased risk of this late sequel. Hearing thresholds of 86 patients with a median age of 31 years (range 21-53 years) and a median follow-up time of 58 months (range 15-159 months) were assessed by conventional pure-tone audiometry. Interviews were conducted evaluating the patients' history with special regard to audiological risk factors, as well as circumstances of ototoxic symptoms. Details concerning treatment and patient variables were extracted retrospectively from the patients' charts. An additional screening programme assessed current body functions, blood parameters and other late toxicities. Symptomatic ototoxicity persisted in 20% of patients (59% tinnitus, 18% hearing loss, 23% both), while 10% had experienced completely reversible ototoxic symptoms for a duration of 1-18 months after treatment. Symptoms were bilateral in 81% of patients. Hearing thresholds were compatible with cisplatin-induced hearing loss in 42% of audiograms performed. Subjective (history) and objective (audiogram) findings were not always consistent. The following statistically significant risk factors for ototoxicity were established: high cumulative dose of cisplatin (P < 0.0001); history of noise exposure (P = 0.006). Additionally, high doses of vincristine (P = 0.001) seemed to result in reversible ototoxic symptoms. No other independent risk factors were identified. In conclusion, persisting ototoxicity represents a clinical sequel for approximately 20% of testicular cancer patients treated at standard dose but may affect more than 50% of patients receiving cumulative doses of cisplatin > 400 mg m(-2). Previous noise exposure may also result in a threefold increased risk for cisplatin ototoxicity. Future studies should use these risk factors as important stratification criteria for trials aiming at the evaluation and prevention of cisplatin-induced ototoxicity.     

Menstrual and reproductive factors and risk of breast cancer in Asian-Americans

We conducted a population-based case-control study of breast cancer among Chinese-, Japanese- and Filipino-American women in Los Angeles County Metropolitan Statistical Area (MSA), San Francisco-Oakland MSA and Oahu, Hawaii. One objective of the study was to quantify breast cancer risks in relation to menstrual and reproductive histories in migrant and US-born Asian-Americans and to establish whether the gradient of risk in Asian-Americans can be explained by these factors. Using a common study design and questionnaire in the three study areas, we successfully conducted in-person interviews with 597 Asian-American women diagnosed with incident, primary breast cancer during the period 1983-87 (70% of those eligible) and 966 population-based controls (75% of those eligible). Controls were matched to cases on age, ethnicity and area of residence. In the present analysis, which included 492 cases and 768 controls, we observed a statistically non-significant 4% reduction in risk of breast cancer with each year delay in onset of menstruation. Independent of age at menarche risk of breast cancer was lower (odds ratio; OR=0.77) among women with menstrual cycles greater than 29 days. Parous Asian-American women showed a significantly lower risk of breast cancer then nulliparous women (OR=0.54). An increasing number of livebirths and a decreasing age at first livebirth were both associated with a lower risk of breast cancer, although the effect of number of livebirths was no longer significant after adjustment for age at first livebirth. Women with a pregnancy (spontaneous or induced abortions) but no livebirth had a statistically non-significant increased risk (OR=1.84), but there was no evidence that one type of abortion was particularly harmful. A positive history of breastfeeding was associated with non-significantly lower risk of breast cancer (OR=.78). There are several notable differences in the menstrual and reproductive factors between Asian-Americans in this study and published data on US whites. US-born Asian Americans had an average age at menarche of 12.12 years-no older than has been found in comparable studies of US whites, but 1.4 years earlier than Asian women who migrated to the US. Asian-American women, particularly those born in the US and those who migrated before age 36, also had a later age at first birth and fewer livebirths than US whites. A slightly higher proportion of Asian-American women breastfed, compared with US whites. The duration of breastfeeding was similar in US-born Asians and US whites, but was longer in Asian migrants, especially those who migrated at a later age. Menstrual and reproductive factors in Asian-American women are consistent with their breast cancer rates being at least as high as in US whites, and they are. However, the effects of these menstrual and reproductive factors were small and the ORs for migration variables changed only slightly after adjustment for these menstrual and reproductive factors. These results suggest that the lower rates of breast cancer in Asians must be largely as a result of other environmental/lifestyle factors.     

Surgery for left-sided pancreatic cancer

A total of 590 exocrine pancreatic cancers of the body or tail of the pancreas, operated on between January 1982 and December 1988, were analysed. There were 128 pancreatic resections (group 1), 164 palliative bypasses (group 2) and 293 exploratory laparotomies which included 74 splanchnicectomies (group 3). The mortality rate was lower in group 1 (9 per cent) than in group 2 (19 per cent) (P = 0.012). The mortality rate exceeded 40 per cent in groups 1 and 2 for patients aged more than 70 years with pre-existing organ failure. The morbidity rate was 32 per cent in group 1 and 29 per cent in group 2. Patients with metastases had a median survival of 3.4 months, whatever the operative treatment. In the presence of lymph node involvement there was no significant difference in survival between groups 1 and 2. Patients with no metastases and no lymph node involvement had 1- and 3-year survival rates of 38 and 12 per cent respectively after pancreatic resection. Only patients with a small tumour (< or = 4 cm), no lymph node involvement and no metastases achieved a significantly better survival after resection (P = 0.049). Curative resection should be reserved for a small tumour confined to the pancreas. Fewer than 10 per cent of patients will be suitable for surgery. For the other cases, resection must be considered as a palliative procedure without a significant improvement in survival. It seems justified to limit palliative surgery to candidates for digestive bypass and to use non-surgical palliation for the remainder.     

Pericholangitis and sclerosing cholangitis are risk factors for dysplasia and cancer in ulcerative colitis

Known risk factors for the development of dysplasia and cancer in ulcerative colitis (UC) patients are: 1) increased extent and duration of disease and 2) increased age at symptom onset. This case-control study was performed to determine whether cholestatic liver disease is associated with neoplastic transformation. Twenty-nine UC patients with extensive disease of long duration and dysplasia or cancer detected in a cancer surveillance program were pair-matched to UC patients without neoplasia from a large inflammatory bowel disease registry matched on extent of disease, sex, and calendar year of disease onset. Of the 29 cases, 10 were found to have cholestatic liver disease; nine with pericholangitis and one with primary sclerosing cholangitis (PSC). Two controls had PSC. Cholestatic liver disease was a significant risk factor for the development of dysplasia or cancer (odds ratio 9.00, 95% confidence interval 1.14-71.0). Increased age at symptom onset also was found to be a significant risk factor for neoplasia (odds ratio 1.04 for each additional year, 95% confidence interval 1.00-1.08) that did not exhibit confounding or interacting effects with cholestatic liver disease. The degree of neoplasia (low-grade dysplasia, high-grade dysplasia, or cancer) did not appeared to affect the results. Therefore, cholestatic liver disease, either pericholangitis or PSC, was significantly associated with the development of dysplasia or cancer in UC patients and should be considered an important risk factor for neoplastic transformation.