Dynamics of the HIV epidemic in southern China: sexual and drug-using behaviours among female sex workers and male clients in Yunnan

To examine the HIV/sexually transmitted infection (STI)-related risk behaviours among community-based female sex workers (FSWs) and their clients in Yunnan Province, China, we performed a cross-sectional study of 705 FSWs and 100 male clients. We found that HIV seroprevalence among FSWs was 13.0% and the most prevalent STI was herpes simplex virus type 2 (HSV-2) (71.1%), followed by Chlamydia trachomatis (18.1%) and syphilis (8.8%). The 20% of FSWs who reported injection drug use also reported needle-sharing behaviours in the last three months. Drug-using FSWs had substantially higher HIV and HSV-2 prevalence, serviced more clients and had a longer history of sex work than non-using FSWs. In total, 57.0% of male clients did not consistently use condoms with FSWs, 2.0% reported illicit drug use and 17.0% had STI symptoms in the last year. The dual risk behaviours of drug-using FSWs and clients place them at greater risk of HIV infection. Intervention programmes must adopt comprehensive methods.

High frequency of low-level microsatellite instability in early colorectal cancer

Molecular events in early colorectal cancers (CRCs) have not been well elucidated because of the low incidence of early CRCs in clinical practice. Therefore, we studied 104 sporadic early CRCs with invasion limited to submucosa compared with 116 advanced CRCs. Loss of heterozygosity as well as microsatellite instability (MSI) status was examined. A significantly high frequency of low-level MSI (MSI-L) phenotype was detected in early CRCs (51.0%) compared with advanced CRCs (25.9%; P = 0.0001). In early and advanced CRCs, samples with MSI-L phenotype differed from microsatellite stable (MSS) phenotype with respect to loss of heterozygosity at 1p32 and 8p12-22. MSI-L is a frequent genetic event in early CRCs and may be a novel pathway in colorectal carcinogenesis distinct from both MSI-H and MSS.

Temporal changes in liver cancer incidence rates in Japan: accounting for death certificate inaccuracies and improving diagnostic techniques

Primary liver cancer (PLC) rates have risen dramatically during the past few decades in some regions, particularly in Japan, where PLC is now the third major cause of cancer death. PLC is one of the most difficult tumors to diagnose correctly, because (i) the liver is a frequent site of cancer metastasis and (ii) death from PLC is often attributed to cirrhosis or chronic hepatitis. Also, because the disease is often rapidly fatal, a large proportion of liver cancer cases are identified based on death certificates alone without confirmation by clinical records. Thus, worldwide differences in published incidence rates for this disease reflect regional or national differences in both the accuracy of death certificates and the sensitivity of diagnostic methods. By comparing death certificate causes of death with those based on pathology review, we were able to adjust 1958--1994 incidence rates for a large Japanese cohort for these errors. Although the death certificate false-positive error rate declined, the false-negative error rate remained high throughout the study. The introduction of improved liver cancer diagnostic methods in Japan in the early 1980s was associated with a sharp increase in PLC incidence. We conclude that errors in death certificate causes of death and changes in liver cancer diagnostic techniques have had an important impact on the reported incidence of this disease. Taking these factors into account, rates of hepatocellular carcinoma rose between 2.4- and 4.3-fold in our Japanese cohort from 1960 to 1985, peaked about 1993 and declined thereafter. Incidence rates of cholangiocarcinoma remained stable through 1987.

Liver cancer in atomic-bomb survivors: histological characteristics and relationships to radiation and hepatitis B and C viruses

Histological features of primary liver cancer among atomic-bomb survivors and their relationship to hepatitis B (HBV) and C viral (HCV) infections are of special interest because of the increased risk of liver cancer in persons exposed to ionizing radiation and the high and increasing liver cancer rates in Japan and elsewhere. We conducted a pathology review of liver cancers occurring from 1958 to 1987 among subjects in the 120,321 member cohort of 1945 Hiroshima and Nagasaki residents. A panel of pathologists classified tumor histological types and defined accompanying cirrhotic changes of the liver. Archival tissue samples were assessed for HBV using pathology stains and PCR. Reverse transcriptase (RT) PCR was used to determine HCV status. We used unconditional logistic regression to compare 302 hepatocellular carcinoma (HCC) cases to 53 cholangiocarcinoma (CC) cases, adjusting for age, year of diagnosis, sex and viral status. Cirrhotic changes occurred significantly more often among HCC than CC cases (76% in HCC and 6% in CC). Compared to CC cases, HCC cases were 10.9 times more likely to be HBV-positive (95% confidence interval: 2.1-83.2) and 4.3 times more likely to be HCV-positive (95% confidence interval: 1.1-20.5). No significant differences were found between HCC and CC cases in radiation exposures. The predominance of HCC in the atomic-bomb survivors follows the background liver cancer pattern in Japan. Our findings suggest that HBV and HCV are involved in the pathogenesis of HCC with or without cirrhosis and are significantly less important in that of CC.

Patterns of memory performance in children with controlled epilepsy on the CVLT-C

Decreased memory skills have been reported in children with epilepsy. However, standardized instruments to evaluate learning and memory in children have been unavailable until recently. The present study was designed to assess memory patterns in children with epilepsy based on the California Verbal Learning Test-Children's Version (CVLT-C). The test was administered to 44 children with complex partial seizures and 21 children with generalized seizures between 8 and 13 years of age. Children in the study had been treated for epilepsy for at least 6 months, had well-controlled seizures on monotherapy, and had no evidence of anticonvulsant toxicity. Children with head injuries, learning disabilities, or hyperactivity were excluded. Test results did not reflect differences in memory performance based on seizure type. Scores for the entire sample indicated intact new learning, decreased intrusions and perseverative responses, and better short-term than long-term delayed recall. Recognition skills were stronger than long-term delayed recall skills and suggested that memory performance may be improved for these children when a multiple-choice format is available in academic settings.

Bladder-cancer incidence in relation to vegetable and fruit consumption: a prospective study of atomic-bomb survivors

We examined the relation between consumption of 22 dietary items and subsequent bladder-cancer incidence in a cohort of atomic-bomb survivors in Japan. Subjects were 38,540 people (14,873 men and 23,667 women) who responded to a mail survey carried out between 1979 and 1981 and who had no known cancer diagnosed before the start of follow-up (1 January 1980 for men, 1 February 1981 for women). Consumption frequencies for 22 dietary items were ascertained with pre-coded answers. As of the end of 1993, there were 114 (83 men and 31 women) incident cases of bladder cancer among 450,326 person-years at risk. Statistical analysis was done using Poisson regression for grouped survival data Consumption of green-yellow vegetables and fruit were protectively associated with risk. Adjusted for gender, age, radiation exposure, smoking status, educational level, body-mass index and calendar time, the relative risk (RR) for those consuming green-yellow vegetables 2-4 times per week and almost everyday was 0.62 [95% confidence interval (CI) 0.39-0.98] and 0.54 (95% CI 0.30-0.94) respectively, as compared with those consuming once per week or less. The corresponding RR for fruit consumption was 0.50 (0.30-0.81) and 0.62 (0.39-0.99) respectively. Chicken consumption was unexpectedly associated with decreased risk, but additional adjustment for consumption did not change the relation of green-yellow vegetables or of fruit to risk. The consumption of the other dietary items, including meat and green tea, was not related to risk. The findings add to evidence that high consumption of vegetables and fruit are protective against bladder cancer.

Soya foods and breast cancer risk: a prospective study in Hiroshima and Nagasaki, Japan

The association between soya foods and breast cancer risk was investigated in a prospective study of 34759 women in Hiroshima and Nagasaki, Japan. Women completed dietary questionnaires in 1969-1970 and/or in 1979-1981 and were followed for incident breast cancer until 1993. The analysis involved 427 cases of primary breast cancer in 488989 person-years of observation. The risk for breast cancer was not significantly associated with consumption of soya foods: for tofu, relative risks adjusted for attained age, calendar period, city, age at time of bombings and radiation dose to the breast were 0.99 (95% CI 0.80-1.24) for consumption two to four times per week and 1.07 (0.78-1.47) for consumption five or more times per week, relative to consumption once a week or less; for miso soup, relative risks were 1.03 (0.81-1.31) for consumption two to four times per week and 0.87 (0.68-1.12) for consumption five or more times per week, relative to consumption once a week or less. These results were not materially altered by further adjustments for reproductive variables and were similar in women diagnosed before age 50 and at ages 50 and above. Among 17 other foods and drinks examined only dried fish (decrease in relative risk with increasing consumption) and pickled vegetables (higher relative risk with higher consumption) were significantly related to breast cancer risk; these associations were not prior hypotheses and, because of the large number of comparisons made, they may be due to chance.

Family history of cancer in children and young adults with colorectal cancer

BACKGROUND

Family history of colorectal cancer among adult patients has been reported in the literature. Although extremely rare in children, colorectal cancer in this population may represent a unique group in whom genetic factors play a significant etiologic role. The aim of the present study was to assess genetic contribution, as measured by family history, to the development of colorectal cancer in probands under 21 years of age at diagnosis.

PROCEDURE

Detailed family histories were obtained from surviving patients or their parents. The risk [standardized incidence ratio (SIR)] of cancer in the relatives was calculated by comparing the observed and the expected incidence based on rates in the general population and person-years at risk.

RESULTS

Twenty-five patients (median age at diagnosis 15 years) diagnosed with colorectal cancer at St. Jude Children's Research Center since 1964 or their surviving next of kin were available for interview. The 461 relatives contributed 18,908 person-years of follow-up. Statistically significant increased risk of colorectal cancer was present among all relatives (SIR = 6.0, 95% CI, 2.7-10.6), and the increased risk of colorectal cancer was confined to relatives of probands who were under 15 years of age at diagnosis (SIR = 10.0, 95% CI, 4.5-17.6). In addition, there was an excess of uterine/cervical cancer among all female relatives (SIR = 6.5, 95% CI, 3.2-10.9).

CONCLUSIONS

The observed excess of colorectal cancer, in relatives of younger probands, suggests the need to examine these kindreds for genetic instability resulting from defects in mismatch repair genes to characterize further the patterns of risk observed.

Cognition and behavior after temporal lobectomy in pediatric patients with intractable epilepsy

The increased use of surgical intervention for intractable epilepsy during childhood has resulted in a critical need for information concerning possible cognitive and behavioral changes in pediatric patients after surgery. In this pilot study, comprehensive neuropsychologic evaluations were completed on nine children who had a temporal lobectomy for intractable epilepsy before 16 years of age. Performances before and after surgery were compared using cognitive and behavioral measures. Repeated measures analysis of variance did not indicate differences in performance on the basis of laterality of surgery, although the number of left (n = 5) vs right (n = 4) temporal resections was small. Paired comparison t tests, which included all patients, did not suggest marked changes in cognitive functioning after surgery, although decreases in delayed verbal memory were evident. Positive effects on quality of life during the first year after surgical intervention were suggested by reduced internalizing symptoms and increased social interaction. Replication of this study is recommended with a larger number of patients and multicenter collaboration.

A comparison of rectal diazepam gel and placebo for acute repetitive seizures

BACKGROUND

Acute repetitive seizures are readily recognizable episodes involving increased seizure frequency. Urgent treatment is often required. Rectal diazepam gel is a promising therapy.

METHODS

We conducted a randomized, double-blind, parallel-group, placebo-controlled study of home-based treatment for acute repetitive seizures. Patients were randomly assigned to receive either rectal diazepam gel, at a dosage varying from 0.2 to 0.5 mg per kilogram of body weight on the basis of age, or placebo. Children received one dose at the onset of acute repetitive seizures and a second dose four hours later. Adults received three doses -- one dose at onset, and two more doses 4 and 12 hours after onset. Treatment was administered by a care giver, such as a parent, who had received special training. The number of seizures after the first dose was counted for 12 hours in children and for 24 hours in adults.

RESULTS

Of 125 study patients (64 assigned to diazepam and 61 to placebo) with a history of acute repetitive seizures, 91 (47 children and 44 adults) were treated for an exacerbation of seizures during the study period. Diazepam treatment was superior to placebo with regard to the outcome variables related to efficacy: reduced seizure frequency (P<0.001) and improved global assessment of treatment outcome by the care giver (frequency and severity of seizures and drug toxicity) (P<0.001). Post hoc analysis showed diazepam to be superior to placebo in reducing seizure frequency in both children (P<0.001) and adults (P=0.02), but only in children was it superior with regard to improvement in global outcome (P<0.001). The time to the first recurrence of seizures after initial treatment was longer for the patients receiving diazepam (P<0.001). Thirty-five patients reported at least one adverse effect of treatment; somnolence was the most frequent. Respiratory depression was not reported.

CONCLUSIONS

Rectal diazepam gel, administered at home by trained care givers, is an effective and well-tolerated treatment for acute repetitive seizures.

Coinfection of wild ducks by influenza A viruses: distribution patterns and biological significance

Coinfection of wild birds by influenza A viruses is thought to be an important mechanism for the diversification of viral phenotypes by generation of reassortants. However, it is not known whether coinfection is a random event or follows discernible patterns with biological significance. In the present study, conducted with viruses collected throughout 15 years from a wild-duck population in Alberta, Canada, we identified three discrete distributions of coinfections. In about one-third of the events, which involved subtypes of viruses that appear to be maintained in this duck reservoir, coinfection occurred at rates either close to or significantly lower than one would predict from rates of single-virus infection. Apparently, the better adapted an influenza A virus is to an avian population, the greater is its ability to prevent coinfections. Conversely, poorly adapted, nonmaintained viruses were significantly overrepresented as coinfectants. Rarely encountered subtypes appear to represent viruses whose chances of successfully infiltrating avian reservoirs are increased by coinfection. Mallards (Anas platyrhynchos) and pintails (A. acuta) were significantly more likely to be infected by a single influenza A virus than were the other species sampled, but no species was significantly more likely to be coinfected. These observations provide the first evidence of nonrandom coinfection of wild birds by influenza A viruses, suggesting that reassortment of these viruses in a natural population does not occur randomly. These results suggest that even though infections may occur in a species, all subtypes are not maintained by all avian species. They also suggest that specific influenza A virus subtypes are differentially adapted to different avian hosts and that the fact that a particular subtype is isolated from a particular avian species does not mean that the virus is maintained by that species.

Late mortality of long-term survivors of childhood cancer

PURPOSE

To determine the frequency and patterns of late mortality among long-term survivors of childhood cancer.

MATERIALS AND METHODS

Medical records of patients who survived at least 5 years after the diagnosis of childhood cancer were reviewed to determine the causes of subsequent deaths. Estimated 15-year survival and standardized mortality ratios for deaths from nonneoplastic treatment complications were compared with adjusted United States population estimates. The study included 2,053 patients who had survived > or = 5 years, grouped by treatment eras that reflected increased intensity of therapy and significantly improved survival (early era, 1962 to 1970; recent era, 1971 to 1983).

RESULTS

There have been 258 subsequent deaths in the 2,053 childhood cancer survivors; 169 occurred 5 to 10 years postdiagnosis and 89 > or = 10 years post diagnosis. For the study period as a whole, deaths were attributed to recurrent primary malignancy in 61% of cases, second malignancy in 20%, nonneoplastic treatment complication in 10%, and unintentional injury/suicide in 8%. Late death from recurrent disease decreased significantly for survivors treated in the recent era (P < .0001), while the risk of death from second malignancies increased, although not statistically significantly (P = .10). Projected 15-year survival estimates for all > or = 5-year survivors in both treatment eras was greater than 90%, but differed from expected rates.

CONCLUSION

Late mortality from recurrence after treatment for childhood cancer decreases with more effective initial therapy. Prolonged disease-free status is associated with an expected survival that approaches that of the general population for patients treated from 1971 through 1983. The impact of more recent intensified and novel therapies for high-risk patients remains to be determined.

Ultrasonography for thyroid screening after head and neck irradiation in childhood cancer survivors

We prospectively used ultrasonography to detect thyroid abnormalities in 96 long-term survivors of childhood cancer, who received head and neck radiation therapy at a median age of 8.9 years. The median time interval since irradiation was 10.8 years (range 5.6-22.8 years). Most survivors of leukemia received 24 Gy cranial irradiation for central nervous system prophylaxis; patients with solid tumors received between 20 and 66 Gy (median 37.5 Gy). The total evaluation included clinical history, physical examination, thyroid function tests, and thyroid ultrasonography; radionuclide scans were performed in patients whose abnormalities persisted on subsequent ultrasound exams. Clinical history and physical examination revealed thyroid abnormalities in 14 patients (15%), but ultrasound detected abnormalities in 42 patients (44%). These findings included inhomogeneity (n = 29), cysts (n = 15), and nodules (n = 22) and occurred in nearly half of patients treated with 15 Gy or more directly to the thyroid gland. Radionuclide scans confirmed the presence of thyroid nodules in 13 of 15 patients with ultrasonographic evidence of nodules. Six patients had thyroid neoplasia, including one case of papillary carcinoma. All patients with neoplasia had nodules demonstrated on ultrasonography. Our experience suggests that in childhood cancer survivors, ultrasonography is a sensitive, affordable, and noninvasive means of detecting subtle parenchymal abnormalities. We recommend thyroid ultrasonography for childhood cancer survivors who received head and neck irradiation. A baseline study should be obtained within 1 year of completion of therapy. The frequency of subsequent examinations should be based on the radiation dose and the patient's age at the time of irradiation.

An epidemiological study of influenza viruses among Chinese farm families with household ducks and pigs

To examine the possibility of interspecies transmission and genetic reassortment of influenza viruses on farms in Southern China, we surveyed 20 farm families living outside the city of Nanchang who raised pigs and ducks in their homes. Weekly interviews of family members and virus isolation studies of throat swabs and faecal samples, collected from September 1992 to September 1993, established the seasonal pattern of respiratory tract infections in these families and identified 11 influenza viruses (6 in humans and 5 in ducks). Most of the human isolates were type A of H3N2 subtype. Serologic studies of farm pigs indicated infection by the same human viruses circulating in family members, but there was no evidence that either swine or avian viruses had been transmitted to pigs. Eight of 156 human serum samples inhibited the neuraminidase activity of two of the duck isolates, raising the possibility of interspecies transmission of these avian viruses. Genotype analysis of duck and human isolates provided no evidence for reassortment. Our finding support the concept that intermingling of humans, pigs and ducks on Chinese farms is favourable to the generation of new, potentially hazardous strains of influenza virus.

Aspirin and reduced risk of esophageal carcinoma

BACKGROUND

Aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs) have been shown experimentally to inhibit chemically induced esophageal cancers. An epidemiologic study of more than 600,000 adults in the United States followed for 6 years found that aspirin use was associated with a reduced risk of death from esophageal cancer.

METHODS

The relation of aspirin use and esophageal cancer was examined using data from the National Health and Nutrition Examination Survey (NHANES I) and the National Epidemiologic Follow-up Studies (NEFS). Of the 14,407 United States residents followed for 12-16 years, esophageal cancer developed in 15. Persons were classified as nonusers, occasional users, or regular users of aspirin based on their response to two questions at the baseline examination: whether they had taken aspirin in the past 30 days and whether they had used pain medications regularly during the prior 6 months.

RESULTS

Occasional use was associated with a 90% decreased risk (95% confidence interval, 0.01-0.76) of developing esophageal cancer, and no person classified as a regular user developed the disease. Adjusting for cigarette smoking (ever vs. never) and alcohol intake (at least monthly vs. not) did not explain the finding.

CONCLUSION

Aspirin use was associated with a 90% decreased risk of developing esophageal carcinoma. Further studies to determine whether aspirin is protective against both squamous cell esophageal carcinoma and adenocarcinoma of the esophagus are indicated.

Aspirin and reduced risk of esophageal carcinoma

BACKGROUND

Aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs) have been shown experimentally to inhibit chemically induced esophageal cancers. An epidemiologic study of more than 600,000 adults in the United States followed for 6 years found that aspirin use was associated with a reduced risk of death from esophageal cancer.

METHODS

The relation of aspirin use and esophageal cancer was examined using data from the National Health and Nutrition Examination Survey (NHANES I) and the National Epidemiologic Follow-up Studies (NEFS). Of the 14,407 United States residents followed for 12-16 years, esophageal cancer developed in 15. Persons were classified as nonusers, occasional users, or regular users of aspirin based on their response to two questions at the baseline examination: whether they had taken aspirin in the past 30 days and whether they had used pain medications regularly during the prior 6 months.

RESULTS

Occasional use was associated with a 90% decreased risk (95% confidence interval, 0.01-0.76) of developing esophageal cancer, and no person classified as a regular user developed the disease. Adjusting for cigarette smoking (ever vs. never) and alcohol intake (at least monthly vs. not) did not explain the finding.

CONCLUSION

Aspirin use was associated with a 90% decreased risk of developing esophageal carcinoma. Further studies to determine whether aspirin is protective against both squamous cell esophageal carcinoma and adenocarcinoma of the esophagus are indicated.

Outcome findings from a multidisciplinary clinic for children with epilepsy

Children with chronic or intractable epilepsy are at higher risk for medical and social difficulties. A multidisciplinary clinic was established to improve medical management and address psychosocial issues. The purposes of the present study were to describe the multidisciplinary clinic, retrospectively examine the referral patterns for children served by the clinic, and analyze factors significantly predictive of parental satisfaction with the multidisciplinary approach. The Epilepsy Clinic Satisfaction Questionnaire was sent to all patients seen in the clinic over a 2-year period. Outcome findings were based on 136 respondents. A stepwise regression analysis indicated that the best predictor of parental rating of clinic quality was the amount of information given concerning the diagnosis and treatment of epilepsy. Staff attitude was also significantly related to parental satisfaction.

Hereditary spastic paraplegia linked to chromosome 15q: Analysis of candidate genes

We previously reported an extended kindred with autosomal dominant uncomplicated hereditary spastic paraplegia (HSP) and found close linkage between the disorder and microsatellite polymorphisms on chromosome 15q. Multipoint linkage analysis reached a maximum LOD score (10.16) between D15S128 and D15S156, a region that includes genes encoding alpha5 and beta3 subunits of GABAA receptor. Theoretically, abnormal GABA-mediated neurotransmission could produce spasticity and possibly other changes of HSP. We used genetic linkage analysis to evaluate these two HSP candidate genes and observed obligate recombinants for polymorphisms immediately adjacent to (or within untranslated regions of) genes encoding alpha5 and beta3 GABAA receptor subunits. Although these genes are linked tightly to the HSP locus, our findings conclusively exclude these genes from being responsible for HSP in this kindred.

Influenza infection in humans and pigs in southeastern China

The three last pandemic strains of influenza A virus-Asian/57, Hong Kong/68 and Russian/77-are believed to have originated in China. The strains responsible for the 1957 and 1968 human pandemics were reassortants incorporating both human and avian influenza viruses, which may have arisen in pigs. We therefore undertook a population-based study in the Nanchang region of Central China to establish the prevalence, types and seasonal pattern of human influenza infection and to screen serum samples from animals and humans for evidence of interspecies transmission of influenza viruses. Two definite influenza seasons were demonstrated, one extending from November to March and the other July to September. The profile of antibodies to commonly circulating human influenza viruses was no different in Nanchang and neighboring rural communities than in Memphis, Tennessee, USA. In particular, Chinese women who raised pigs in their homes were no more likely to have been exposed to influenza virus than were subjects who seldom or never had contact with pigs. However, we did obtain evidence using isolated H7 protein in an enzyme-linked immunoabsorbent assay for infection of pig farmers by an avian H7 influenza virus suggesting that influenza. A viruses may have been transmitted directly from ducks to humans. The results of the serological survey also indicated that pigs in or near Nanchang were infected by human H1N1 and H3N2 influenza viruses, but not with typical swine viruses. We found no serological evidence for H2 influenza viruses in humans after 1968.

Genetic reassortment in pandemic and interpandemic influenza viruses. A study of 122 viruses infecting humans

The human influenza pandemics of 1957 and 1968 were caused by reassortant viruses that possessed internal gene segments from avian and human strains. Whether genetic reassortment of human and avian influenza viruses occurs during interpandemic periods and how often humans are infected with such reassortants is not known. To provide this information, we used dot-blot hybridization, partial nucleotide sequencing and subsequent phylogenetic analysis to examine the 6 internal genes of 122 viruses isolated in humans between 1933 and 1992 primarily from Asia, Europe, and the Americas. The internal genes of A/New Jersey/11/76 isolated from a human fatality at Fort Dix, New Jersey in 1976 were found to be of porcine origin. Although none of the geographically and temporally diverse collection of 122 viruses was an avian-human or other reassortant, cognizance was made of the fact that there were two isolates from children from amongst 546 influenza A isolates obtained from The Netherlands from 1989-1994 which were influenza A reassortants containing genes of avian origin, viruses which have infected European pigs since 1983-1985. Thus, genetic reassortment between avian and human influenza strains does occur in the emergence of pandemic and interpandemic influenza A viruses. However, in the interpandemic periods the reassortants have no survival advantage, and the circulating interpandemic influenza viruses in humans do not appear to accumulate avian influenza virus genes.

Aspirin and reduced risk of esophageal carcinoma

BACKGROUND

Aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs) have been shown experimentally to inhibit chemically induced esophageal cancers. An epidemiologic study of more than 600,000 adults in the United States followed for 6 years found that aspirin use was associated with a reduced risk of death from esophageal cancer.

METHODS

The relation of aspirin use and esophageal cancer was examined using data from the National Health and Nutrition Examination Survey (NHANES I) and the National Epidemiologic Follow-up Studies (NEFS). Of the 14,407 United States residents followed for 12-16 years, esophageal cancer developed in 15. Persons were classified as nonusers, occasional users, or regular users of aspirin based on their response to two questions at the baseline examination: whether they had taken aspirin in the past 30 days and whether they had used pain medications regularly during the prior 6 months.

RESULTS

Occasional use was associated with a 90% decreased risk (95% confidence interval, 0.01-0.76) of developing esophageal cancer, and no person classified as a regular user developed the disease. Adjusting for cigarette smoking (ever vs. never) and alcohol intake (at least monthly vs. not) did not explain the finding.

CONCLUSION

Aspirin use was associated with a 90% decreased risk of developing esophageal carcinoma. Further studies to determine whether aspirin is protective against both squamous cell esophageal carcinoma and adenocarcinoma of the esophagus are indicated.

Interspecies transmission of influenza viruses

In this report we examine the hypothesis that aquatic birds are the primordial source of all influenza viruses in other species. Two partly overlapping reservoirs of influenza A viruses exist in migrating water-fowl and shorebirds throughout the world. These species harbor influenza viruses of all the known hemagglutinin and neuraminidase subtypes. In contrast to the rapid, progressive changes in both the nucleotide and amino acid sequences of mammalian virus gene lineages, avian virus genes show far less variation and, in most cases, appear to be in evolutionary stasis. There are periodic exchanges of influenza virus genes or whole viruses between species, giving rise to pandemics of disease in humans, lower animals, and birds. The periodic exchange of influenza viruses between species has been illustrated by the appearance of new pandemic influenza viruses in humans, including the Spanish influenza of 1918, the Asian influenza of 1957, and the Hong Kong influenza of 1968. Transmission of avian influenza viruses to swine in Europe in 1979 has resulted in the appearance of human-avian reassortant influenza viruses in pigs in Italy and in children in the Netherlands. These studies provide evidence supporting the possibility that pigs serve as a mixing vessel for reassortment between influenza viruses in mammalian and avian hosts and raise the question of whether the avian influenza viruses now circulating in European swine are the precursors of the next human pandemic virus.

Misclassification of nutrient and energy intake from use of closed-ended questions in epidemiologic research

The authors investigated the effect of collecting food frequency intake data using questionnaires that record response intervals rather than exact frequencies of consumption. Measures of energy and 24 nutrients were calculated using both types of frequency data for subjects' mean intakes, rank classifications and group mean values. Frequency data obtained between 1987 and 1989 using the open-ended Health Habits and History Questionnaire (HHHQ) developed by Block and associates at the National Cancer Institute were recoded into the interval response formats used by the computer-scannable version of the HHHQ and into the format used in the food frequency questionnaire developed by Willett for the Nurses' Health Study and other studies. Compared with the open-ended HHHQ, for otherwise identical data sets, the closed-ended HHHQ and Willett response categories produced significantly different (p < 0.05) measures of intake on the individual level for 18 (72%) (HHHQ) and 16 (64%) (Willett) of the 25 nutrient and energy measures studied, and they ranked 13-53% (HHHQ) and 16-52% (Willett) of subjects in different quintiles for the various measures. Use of food frequency questionnaires with closed-ended response categories causes nondifferential misclassification that could bias study results. To reduce such misclassification in epidemiologic studies, the authors recommend that food frequency questionnaires obtain exact frequencies of intake for measurement of diet exposure, and they describe an open-ended questionnaire layout which does so and also permits computer scanning of data.

Autosomal dominant, familial spastic paraplegia, type I: clinical and genetic analysis of a large North American family

"Familial spastic paraplegia" (FSP) refers to clinically and genetically diverse syndromes characterized by insidiously progressive lower extremity spasticity. We evaluated 126 members of a large kindred, including 31 affected subjects, in which FSP was transmitted as a stereotyped, autosomal dominant disorder that showed complete genetic penetrance. Affected subjects developed insidiously progressive gait disturbance between ages 12 and thirty-five. Neurologic examination revealed hyperreflexia and spasticity in the lower extremities, weakness of hip flexion and ankle dorsiflexion, extensor plantar response, diminished vibratory sense in the feet, and pes cavus. Using genetic linkage analysis, we excluded the FSP1 locus on chromosome 14q11.2 as the disease locus in this family. We present the clinical and genetic features of FSP type I, including the age-adjusted risk of developing the disorder in this family.

Autosomal dominant familial spastic paraplegia: tight linkage to chromosome 15q

Autosomal dominant, uncomplicated familial spastic paraplegia (FSP) is a genetically heterogeneous disorder characterized by insidiously progressive lower-extremity spasticity. Recently, a locus on chromosome 14q was shown to be tightly linked with the disorder in one of three families. We performed linkage analysis in a kindred with autosomal dominant uncomplicated FSP. After excluding the chromosome 14q locus, we observed tight linkage of the disorder to a group of markers on chromosome 15q (maximum two-point lod score 9.70; theta = .05). Our results clearly establish the existence of a locus for autosomal dominant FSP in the centromeric region of chromosome 15q. Comparing clinical and genetic features in FSP families linked to chromosome 14q with those linked to chromosome 15q may provide insight into the pathophysiology of this disorder.

Results of temporal lobectomy for the treatment of partial complex epilepsy

Epilepsy is the third most common cause of neurologic disability. The disease carries a 15 prevalence and a 3.5% lifetime risk. Seventy percent of patients can achieve good seizure control with medication. The remaining 30%, some 360,000 people across the United States, have intractable epilepsy and would benefit from evaluation at an epilepsy specialty center where surgical intervention is an option. The following report reviews a series of 50 patients referred to the Arkansas Comprehensive Epilepsy Program for treatment of intractable complex partial epilepsy. In this series, we evaluate results of temporal lobectomy, commenting upon factors in the patients' histories which may influence their outcomes.

Epilepsy and pregnancy: mother and child

Pregnancy in women that have epilepsy is not contraindicated. Definite associated risks do exist but are not as great as once believed. The woman of child bearing age with epilepsy should be educated and informed about the risk of increased seizures and the complications associated with the pregnancy and AED's. Seizure frequency may increase in one-third to one-half of women during pregnancy. AED serum levels decrease during pregnancy and may have a negative impact on seizure control. The risks for mother and child produced by generalized convulsions and especially status epilepticus far outweigh the potential risks associated with AED's. Prenatal obstetrical and neurological care during pregnancies of women with epilepsy is mandatory and can result in an improved outcome. All AED's do have some teratogenic potential, but this is much less than previously described. An understanding of the risks associated with epilepsy and pregnancy and appropriate therapy will result in a better outcome for both mother and child.

The diagnosis and classification of epileptic seizures

Appropriate classification of epileptic seizures is possible based on clinical historical, physical, and laboratory findings. Specific seizure types are more likely to respond to selected antiepileptic drugs (AED's). Correct classification allows for the selection of the appropriate AED and thus increases the likelihood of seizure control. There are numerous epilepsy syndromes or specific types of epilepsy and their description is beyond the scope of this article. The selection of treatment and the description of presently available and future AED's will be discussed in subsequent articles.

Analysis of the influenza virus gene pool of avian species from southern China

Although Southern China has been considered the epicenter of human influenza pandemics, little is known about the genetic composition of influenza viruses in lower mammals or birds in that region. To provide information on the molecular epidemiology of these viruses, we used dot blot hybridization and phylogenetic methods to study the internal genes (PB1, PB2, PA, NP, M, and NS) of 106 avian influenza A viruses isolated from a total of 11,798 domestic ducks, chickens, and geese raised in Southern China including Hong Kong. All 636 genes examined were characteristic of avian influenza viruses; no human or swine influenza genes were detected. Thus, influenza virus reassortants do not appear to be maintained in the domesticated birds of Southeast Asia, eliminating opportunities for further gene reassortment. Phylogenetic analysis showed that the internal genes of these viruses belong to the Eurasian avian lineage, supporting geographical separation of the major avian lineages. The PB1 genes were most similar to A/Singapore/57 (H2N2) and Hong Kong (H3N2) viral genes, supporting an avian origin for the recent human H2N2 and H3N2 pandemic strains. The majority of internal genes from avian influenza viruses in Southern China belong to the Eurasian lineage and are similar to viruses that have recently been transmitted to humans, swine, and horses. This study provides evidence that the transmission of avian influenza viruses and their genes to other species is unidirectional and that the transmission of mammalian influenza virus strains to domestic poultry is probably not a factor in the generation of new pandemic strains.

Wild ducks are the reservoir for only a limited number of influenza A subtypes

Analysis of cloacal samples collected from 12,321 wild ducks in Alberta, Canada, from 1976 to 1990 showed influenza A infections to be seasonal, with prevalences increasing as the population became increasingly more dense. Viruses with 3 haemagglutinin (H3, H4, and H6) and 3 neuraminidase subtypes (N2, N6, and N8) were found consistently to infect both adult and juvenile ducks each year, indicating that wild ducks may be a reservoir for these viruses. In contrast, viruses with 7 haemagglutinin (H2, H5, H7, H8, H9, H11, and H12) and 3 neuraminidase subtypes (N1, N3, and N4) were not found for prolonged periods during the study; when they were found, they primarily infected juveniles at moderate levels. Whilst wild ducks appear to perpetuate some influenza A viruses, they apparently do not act as a reservoir for all such viruses.

Prevalence of smoke detectors and safe tap-water temperatures among welfare recipients in Memphis, Tennessee

The poor are at high risk for fire- and scalding-related injuries and deaths, many of which could be prevented by installing smoke detectors and reducing residential tap-water temperatures to safe levels. The goal of this study was to measure the prevalence of smoke detectors and safe tap-water temperatures among welfare recipients and compare subjects living in safe and unsafe homes. We interviewed 109 black women residing in inner-city Memphis who were receiving Aid to Families with Dependent Children and inspected their homes for functional smoke detectors and safe tap-water temperatures. Of the 533 residents reported to live in the homes visited for this study, 53.1% were not protected by smoke detectors. More crowded residences were substantially more likely to lack detectors. Most of the smoke detectors which were present were provided by landlords. Of 69 smoke detectors examined, 17.4% did not work. Of the 153 children age 0-5 years living in the homes we visited, 79.1% lived in residences with excessively hot tap water (> 54 degrees C). We conclude that additional efforts are needed to increase the use of smoke detectors and to decrease excessively hot tap water in the homes of welfare recipients.

Interspecies transmission and reassortment of influenza A viruses in pigs and turkeys in the United States

Genetic reassortment between influenza A viruses in humans and in animals and birds has been implicated in the appearance of new pandemics of human influenza. To determine whether such reassortment has occurred in the United States, the authors compared the genetic origins of gene segments of 73 swine influenza virus isolates (1976-1990), representing 11 states, and 11 turkey virus isolates (1980-1989), representing eight states. The host origin of gene segments encoding the internal proteins of H1N1 swine and turkey influenza viruses was identified by developing a dot-blot assay. All gene segments of swine influenza viruses were characteristic of influenza virus genes from that species, indicating that pigs may not be frequent participants in interspecies genetic exchange and reassortment of influenza viruses in the United States. In contrast, 73% of the turkey influenza virus isolates contained genes of swine origin. One turkey isolate was a reassortant having three genes characteristic of avian influenza virus and three of swine origin. These findings document a high degree of genetic exchange and reassortment of influenza A viruses in domestic turkeys in the United States. The molecular biologic techniques used by the authors should aid future epidemiologic studies of influenza pandemics.

Evaluation of a pharmacy-managed warfarin-monitoring service to coordinate inpatient and outpatient therapy

The effects of implementing a warfarin-monitoring service for inpatients were evaluated. The pharmacy-managed service includes chart review, laboratory interpretation, recommendations for warfarin dosage adjustments, physician and patient education, and coordination of follow-up in the outpatient anticoagulation clinic. In a before-after trial, 52 patients monitored by the warfarin-monitoring service were compared with 97 patients who received warfarin before the service was implemented. Significantly fewer determinations of prothrombin time (PT) and partial thromboplastin time (PTT) were ordered for after-trial patients compared with before-trial patients. PT stability at hospital discharge was significantly improved in after-trial patients. After-trial patients were 12.2 times more likely to be referred to the anticoagulation clinic. No difference was found between the before and after groups in overall compliance with follow-up; however, among patients with no history of substance abuse, after-trial patients were 6.7 times more likely to be compliant. The warfarin-monitoring service had no significant effect on the number of hospital visits and readmissions related to toxicity and recurrence of thrombosis. After-trial patients were 5.4 times more likely to have a therapeutic PT at the initial follow-up appointment. The warfarin-monitoring service improved warfarin dose determination, improved PT stability, and increased referrals to the anticoagulation clinic; among patients with no history of substance abuse, it also improved clinic compliance.

Use of restraint devices to prevent collision injuries and deaths among welfare-supported children

Evidence that death and injury rates for young children involved in automobile collisions could be reduced if children were restrained prompted the State of Tennessee to pass the nation's first child passenger law, a law that became effective in January 1978. Although similar laws have now been enacted throughout the United States, usually restraint devices are not provided to low-income groups who may have difficulty affording them. Few studies have examined the use of such devices by welfare recipients. A total of 56 black women, receiving Medicaid and residing in inner city Memphis, were interviewed about their use of passenger restraints during automobile travel for their children ages 0-3 years. About two-thirds of the mothers interviewed said they rarely or never used child passenger restraint devices when transporting their child. Children age 3 years were significantly less likely to be transported in child restraint devices than younger children. Women who had received welfare payments for 3 years or more or who made fewer than one automobile trip a week with their child were significantly less likely to use child passenger restraints. These results suggest that, in spite of child passenger laws, automobile restraint devices are not used for a high percentage of children ages 0-3 years receiving medical care under State and Federal Medicaid programs. Since treatment costs are paid under these programs when children are injured in collisions, program administrators may have strong incentives to increase the proportion of these children being restrained while traveling in motor vehicles.

Identification of risk factors for diethylstilbestrol-associated clear cell adenocarcinoma of the vagina: similarities to endometrial cancer

This epidemiologic case-control study describes risk factors for clear cell adenocarcinoma of the vagina among 106 cases and 447 controls with in utero exposure to diethylstilbestrol (DES). Controlling for age, socioeconomic status, and time during gestation of initial DES exposure, the authors found a significantly increased risk of this cancer in women who were taller or more obese then their contemporaries at age 14-15 years. The relative risk of this cancer for women in the highest tertile for height compared with those in the lowest tertile was 2.5 (95% confidence interval 1.23-4.90). The relative risk from a similar comparison of body mass was 2.8 (95% confidence interval 1.20-6.53). Trend tests indicated that both factors had significant dose-response relations with risk of vaginal clear cell adenocarcinoma. These findings are particularly interesting since height and body mass are risk factors for endometrial cancer. DES-positive cases interviewed more than 10 years after diagnosis were also significantly thinner than cases interviewed less than 7 years after diagnosis (p = 0.01), providing the first evidence that adolescent adiposity level is associated with survival times for women with this disease.

Atypical electroencephalographic pattern in a patient with subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) has become rare since the widespread use of the measles vaccine. In this patient with a 5 month history of seizures and progressive dementia due to SSPE, the atypical electroencephalographic pattern was characterized by generalized spike-and-wave discharges, maximal on the right, associated with clinical seizures. After diazepam (intravenously), more typical periodic complexes appeared.

Clear cell adenocarcinoma of the lower genital tract. Correlation of mother's recall of diethylstilbestrol history with obstetrical records

The written obstetric records of maternal exposure to diethylstilbestrol (DES) were used as a criterion standard and compared with the DES exposure history recalled by mothers of women with vaginal, cervical, or indeterminable vaginal/exocervical clear cell adenocarcinoma. Among cervical cases, the sensitivity of maternal recall was 50% (N = 2), and its specificity was 100%. Among vaginal and vaginal/exocervical cases, this sensitivity was 72%; specificity was 60%; and the majority of these mothers who said they did not take DES were DES positive by written records. Thus investigators should avoid using maternal recall alone to measure DES exposure. Among subjects for whom written maternal obstetric records were available, 88% of vaginal cases and 46% of cervical cases were DES positive. The authors conclude that few cases of vaginal clear cell adenocarcinoma should occur in young women as the cohort of women exposed in utero to DES continues to age, whereas cases of cervical origin may continue to occur.

Vaginal bleeding and diethylstilbestrol exposure during pregnancy: relationship to genital tract clear cell adenocarcinoma and vaginal adenosis in daughters

Comparing 186 cancer cases and 1772 cancer-free controls and reexamining several previously published studies, we found genital tract clear cell adenocarcinoma and vaginal adenosis to be moderately, but nonsignificantly, associated with vaginal gestational bleeding when in utero diethylstilbestrol exposure was statistically controlled. Considering the prevalence of diethylstilbestrol exposure in the general population, the relative risks of vaginal clear cell adenocarcinoma for in utero exposure were 365.6 and 459.0 when vaginal bleeding did and did not occur during the index pregnancy, respectively. The relative risks of vaginal adenosis for such diethylstilbestrol exposure were 15.4 and 92.8, respectively, for these women. The strong associations between in utero diethylstilbestrol exposure and both vaginal adenosis and genital tract clear cell adenocarcinoma cannot be attributed to the occurrence of problem pregnancy. However, among daughters exposed to diethylstilbestrol, maternal vaginal bleeding during the index pregnancy does appear to be associated with reduced risks of vaginal adenosis and vaginal clear cell adenocarcinoma.

Medical appraisal during health hazard evaluations involving workers exposed to lead

To evaluate the medical aspects of the Health Hazard Evaluation (HHE) program of the National Institute for Occupational Safety and Health (NIOSH), 170 lead-related HHE reports published through 1984 were examined. The percentages of HHEs conducting basic medical examination procedures justified by elevated environmental exposure to lead at worksites were as follows: blood or urine lead level testing, 57%; medical history taking, 55%; physical examinations, 23%; CBCs, 18%; and urinalysis, 7%. The HHE program has primarily focused on whether or not environmental worksite hazards are present at the time of the evaluation and not on ascertaining whether there is evidence of adverse health effects attributable to past worksite exposures. The program has not focused on minimizing adverse health effects when they exist or on providing a series of building blocks for health effects research. More clearly defined HHE program goals and a logic for deciding when and how medical examinations should be performed during HHEs need to be developed.

The neurotoxicity of cyclotrimethylenetrinitramine (RDX) in a child: a clinical and pharmacokinetic evaluation

Cyclotrimethylenetrinitramine (RDX) is a highly explosive compound frequently used for both military and civilian purposes. Previously reported cases of human RDX intoxication were limited to wartime settings and have described no human pharmacokinetic data. We report the first human intoxication to occur in a non-wartime setting. This intoxication presented with status epilepticus in a child and permitted the description of RDX human pharmacokinetics. It also suggested a strong association between central nervous system dysfunction and RDX intoxication.