R-cadherin expression in the developing and adult zebrafish visual system.

Cell adhesion molecules in the cadherin family have been implicated in histogenesis and maintenance of cellular structure and function in several organs. Zebrafish have emerged as an important new developmental model, but only three zebrafish cadherin molecules have been identified to date (N-cadherin, paraxial protocadherin, and VN-cadherin). We began a systematic study to identify other zebrafish cadherins by screening zebrafish cDNA libraries using an antibody raised to the cytoplasmic domain of mouse E-cadherin. Here, we report a partial cDNA with extensive sequence homology to R-cadherin. Spatial and temporal expression of this putative zebrafish R-cadherin was examined in embryos and adults by Northern analysis, RNase protection, and in situ hybridization. R-cadherin message increased during embryogenesis up to 80 hours postfertilization (hpf) and persisted in adults. In the embryonic brain, R-cadherin was first expressed in groups of cells in the diencephalon and pretectum. In adult zebrafish brain, R-cadherin continued to be expressed in several specific regions including primary visual targets. In the retina, R-cadherin was first detected at about 33 hours postfertilization in the retinal ganglion cell layer and the inner part of the inner nuclear layer. Expression levels were highest during periods of axon outgrowth and synaptogenesis. Retrograde labeling of the optic nerve with 1,1'-dioctadecyl-3,3,3',3', tetramethylindocarbocyanine perchlorate (DiI) followed by in situ hybridization confirmed that a subset of retinal ganglion cells in the embryo expressed R-cadherin message. In the adult, R-cadherin expression continued in a subpopulation of retinal ganglion cells. These results suggest that R-cadherin-mediated adhesion plays a role in development and maintenance of neuronal connections in zebrafish visual system.

Increased moth herbivory associated with environmental stress of pinyon pine at local and regional levels.

Using 6 years of observational and experimental data, we examined the hypothesis that water and nutrient stress increase the susceptibility of pinyon pine (Pinus edulis) to the stem- and cone-boring moth (Dioryctria albovittella). At two geographic levels, a local scale of 550 km2 and a regional scale of 10,000 km2, moth herbivory was strongly correlated with an edaphic stress gradient. At a local scale, from the cinder soils of Sunset Crater to nearby sandy-loam soils, nine of ten soil macro- and micronutrients, and soil water content were lowest in cinder-dominated soils. Herbivore damage was six times greater on trees growing in the most water and nutrient deficient site at Sunset Crater compared to sites with well-developed soils. Percentage silt-clay content of soil, which was highly positively correlated with soil nutrient and soil moisture at a local scale, accounted for 56% of the variation in herbivory at a regional scale among 22 sites. Within and across sites, increased stem resin flow was positively associated with reduced moth attack. On the basis of moth distribution across a stress gradient, we predicted that pinyons growing in highly stressful environments would show increased resistance to herbivores if supplemented with water and/or nutrients. We conducted a 6-year experiment at a high-stress site where individual trees received water only, fertilizer only, and water + fertilizer. Relative to control trees, stem growth and resin flow increased in all three treatments, but only significantly in the water + fertilizer treatment. Although there was no significant difference in herbivore damage among these three treatments, there was an overall reduction in herbivore damage on all treatment trees combined, compared to control trees. This experiment suggests that release from stress leads to increased resistance to insect attack and is consistent with our observational data. While other studies have predicted that short-term stress will result in herbivore outbreaks, our studies extend this prediction to chronically stressed host populations. Finally, while flush-feeders are not predicted to respond positively to stressed host plants, we found a positive association between herbivore attack and stressed pinyon populations.

Patient perception of quality of life after burn injury. Results of an eleven-year survey.

The purpose of this study was to assess how patients with burns perceive their physical, psychological, social, and economic status since their burn injuries and to examine the question, "Does burn severity or age at the time of injury affect the patient's perception of his or her quality of life after burn injury?" A 25-item questionnaire was mailed to 1837 former patients who had been hospitalized in our adult burn center from 1975 to 1987, and 245 (13.1%) completed questionnaires were returned. The chi 2 test suggests that the patient sample overall did not experience a change in perceptions after burn injuries. However, when the adult group is divided by burn severity (grouped into low and high percent of burn) and by age at the time of injury (grouped into young and old), both the young and the older persons with high burn severity identify impairments in their quality of life after burn injury.

"Burn repeaters" and injury control.

The purposes of this study were (1) to identify the percentage of patients with burns or intergenerational family members who have had previous burn injuries that required hospitalization and (2) to assess the need for an inpatient burn prevention program for patients and families. This study revealed an increase from 8% to 19% "burn repeaters," with a yearly average of 13% in a 5-year census and a 20.1% etiologic fraction related to the marker of increased risk (previous burn injury). These results strongly substantiate the necessity for an inpatient prevention program for patients and families to promote injury control by reduction of subsequent burn injury and thus break the burn injury cycle.

The relationship of patient stress to burn injury.

The stress of burn injury can have an especially profound psychologic effect on individuals with recent histories of stress life events. A review of the literature reveals a model for this effect and documents the possibility of burn-prone patients, a concept that may explain the high number of patients with burns who also report a high level of stress before injury. This study was designed to assess the proportion of patients with burns reporting previous stress and to assess the relationship of this stress to burn injury and its exacerbating effects. A definite correlation between previous stress and burn injury was found, indicating that many patients with burns may have been in a vulnerable state at injury. Since such vulnerable patients will show a more severe reaction and more serious level of psychologic dysfunction than the seriousness of their injuries might indicate, their identification would have decided benefits in their psychologic rehabilitation.

Surveillance for dust storms and respiratory diseases in Washington State, 1991.

Southeast Washington State, which has a long history of seasonal dust storms, experienced 2 d of dust storms in October 1991, during which PM10 levels exceeded 1,000 micrograms/m3 (i.e., six times greater than the Environmental Protection Agency's 24-h PM10 standard). Three community hospitals in southeast Washington were visited for the purpose of assessing the possible effects of dust storms on respiratory health. During these visits, the number of emergency room visits for respiratory disorders for each day of 1991 were abstracted. These numbers were compared with daily PM10 levels for 1991. Also determined were the observed/expected ratios for the number of emergency room visits for each respiratory disorder category during October 1991. The maximum observed/expected ratio for the respiratory disorders was 1.2. For 1991, we found a 3.5% increase in the number of daily emergency room visits for bronchitis for each 100 micrograms/m3 increase in PM10. In addition, 2 d subsequent to those days on which the PM10 levels exceeded 150 micrograms/m3, there was a 4.5% increase in the number of emergency room visits for sinusitis for each 100 micrograms/m3 increase in PM10. Our results indicate that the naturally occurring PM10 in this setting has a small effect on the respiratory health of the population in general.

Investigating cancer clusters.

A cluster is a mini-epidemic of a rare disease. Clusters may give clues to the etiology of disease, or may signal a hazardous exposure. Unfortunately, cluster investigations seldom are conclusive, for several reasons. Statistically significant clusters can occur by chance. The probability of finding chance cancer clusters is calculated for the 200 Alaska Native villages. The problem of selection bias is explained, and other limitations of epidemiology are described. A logical, stepwise protocol for investigating cancer clusters is presented.

Cross-modal utilization of information: recognition memory for environmental stimuli.

In a study of cross-modal recognition memory for vision and audition photographs were matched for meaningful content with naturalistic sounds. Fifteen subjects inspected pictures and were tested with sounds and for 15 other the procedure was reversed. The two cross-modal groups were further divided into subgroups of 5 to test at one of three delays: immediate, 2 days, or 7 days. Accuracies for recognition of vision-audition for the respective retention intervals were 88.0%, 81.8%, and 75.4% and for audition-vision 87.9%, 85.1%, and 76.7%. Delay interval significantly affected cross-modal recognition. There was no interaction. Vision-audition recognition accuracy did not differ from audition-vision. The cross-modal recognition for both was high. Neither differed from a comparable intra-modal recognition memory for naturalistic sounds (Lawrence, 1974).

Report on blind subjects' tactile and auditory recognition for environmental stimuli.

In two related experiments on recognition-on touch and audition-accuracy rates were obtained from congenitally blind subjects and compared with those for normally sighted subjects. In Exp. 1, 5 blind subjects inspected, i.e., handled, 150 common objects and were tested after a delay of 7 days. In Exp. 2, 9 blind subjects listened to 194 naturalistic sounds and were also tested after a 7-day delay. Accuracy of tactile recognition for the blind was 89.4% while it was 87.9% for the normally sighted. Sound recognition by blind subjects was 76.6% and for the normally sighted it was 78.4%. Neither difference was statistically significant.

Comparison of accuracy in auditory and tactile recognition memory for environmental stimuli.

Accuracy rates for auditory and tactile recognition of naturalistic stimuli over a 7-day period are compared. 40 subjects listened to 50, 107, or 194 naturalistic sounds and were tested immediately or after delays of 2 or 7 days. 30 other subjects handled but did not visually inspect 150 common objects and were tested over the same three delay intervals. Recognition accuracy for sounds was 87.5%, 82.5%, and 80.4% while common objects were recognized at 96.0%, 93.8%, and 88.5% rates of accuracy. Tactile recognition memory was superior to auditory recognition memory. The recognition accuracies of both modalities were affected by the delay interval. The number of items inspected had no effect on the recognition memory for sounds. Following a delay of 1 wk., the accuracy of recognition relative to the original level of function was 92% for both modalities.

Influence of active encoding on tactile recognition memory for common objects.

Active tactile recognition memory for common objects is compared with passive touch. The recognition memory test occure after a delay between inspection and test of seven days. Three groups of five each have the following conditions and results: Group I manipulated objects at both inspection and test to obtain a recognition rate of 87.9%; Group II manipulated objects at inspection but not at test, i.e., passive touch, to produce a recognition rate of 80.7%; Group III manipulated objects at test but not at inspection to perform at a 72.5% accuracy rate. Object manipulation had a significant effect and the group means were all significantly different (p less than or equal to .05), with the largest performance decrement due to passive touch at encoding. Generally, the findings implicated the importance of object identity in tactile recognition memory which, in turn, is supportive of the depth-of-processing approach to memory.

Prevalence, knowledge and care patterns for gastro-oesophageal reflux disease in United States minority populations.

BACKGROUND: While there is evidence of ethnic variation in the prevalence of gastro-oesophageal reflux disease (GERD) symptoms, few population-based studies examine GERD symptom prevalence amongst the growing Hispanic minority in the US as well as Asians in the West. AIM: To examine the prevalence, awareness and care patterns for GERD across different ethnic groups. METHODS: A population-based, cross-sectional survey was fielded in English, Chinese and Spanish that assessed self-reported GERD prevalence, awareness and care patterns in four ethnic groups (Caucasian, African American, Asian, Hispanic). RESULTS: A total of 1172 subjects were included for analysis: 34.6% experienced GERD symptoms at least monthly, 26.2% at least weekly and 8.2% at least daily. Statistically significant differences in raw prevalence rates between racial groups were found: 50% of Hispanics experienced heartburn at least monthly, compared with 37% of Caucasians, 31% of African Americans and 20% of Asians (P > 0.0001). Significant differences in knowledge and care-seeking patterns by ethnicity were also observed. CONCLUSIONS: This study confirms the high prevalence of GERD symptoms in the US and introduces Hispanics as the ethnicity with the highest prevalence rate. Asians in the US have higher rates of symptoms than in the Far East. These data demonstrate a need for culturally appropriate education about GERD symptoms and treatment.

Environmental causes of cancer among Native Americans.

Age-adjusted mortality from cancer is steadily increasing among Native Americans, raising concern about environmental causes. Toxic waste dumps, mining activities, paper mills, military activities, agricultural chemicals, and urban pollution are common sources of carcinogen exposure on reservations and among the urban poor. Despite documented hazards, we do not see a pattern of cancer excess that might result if Native Americans were exposed to these carcinogens more than other Americans. Abuse of tobacco can be shown to be the most important contributor to cancer mortality among Native Americans. Although there are good reasons for environmental regulation and clean-up, the most cost-effective method of cancer prevention is tobacco control.

Unintentional carbon monoxide-related deaths in the United States, 1979 through 1988.

OBJECTIVE: To describe the epidemiology of recent unintentional carbon monoxide poisoning deaths in the United States. DESIGN: Descriptive analysis of carbon monoxide-related deaths in the United States from 1979 through 1988, based on death certificate reports compiled by the National Center for Health Statistics. POPULATION STUDIED: All US deaths, 1979 through 1988. RESULTS: We reviewed data from 56,133 death certificates that contained codes implicating carbon monoxide as a contributing cause of death. Of these, 25,889 were suicides, 210 were homicides, 15,523 were associated with severe burns or house fires, and 11,547 were classified as unintentional. The number of unintentional deaths decreased steadily by about 63 deaths per year, from 1513 in 1979 to 878 in 1988. The highest death rates occurred in winter and among males, blacks, the elderly, and residents of northern states. Motor vehicle exhaust gas caused 6552 (57%) of the unintentional deaths; 5432 (83%) of these were associated with stationary automobiles. CONCLUSIONS: The rate of unintentional death from carbon monoxide poisoning is decreasing. This may be attributable to improvements in automobile pollution control systems and improved safety of cooking and heating appliances. Prevention programs should target young drivers, males, and the elderly.

Patterns of cancer mortality among Native Americans.

BACKGROUND: Native Americans have been reported to have lower cancer incidence and mortality than other racial groups in the U.S., although some have questioned whether this was due to racial misclassification. This study provides improved estimates of cancer mortality, determined from a sampling of people who live on Indian reservations. METHODS: The authors reviewed death certificates from U.S. counties that contain Indian lands, excluding certain areas with known problems of racial misclassification. Age-adjusted mortality rates for specific types of cancer were calculated using U.S. Census population figures, and these rates were compared with rates for all races in the U.S. RESULTS: This sample included 38% of the American Indian and Alaska Native populations. The age-adjusted annual mortality rate for all cancers combined was 148.2 per 100,000 for both genders, 133.1 for females, and 167.2 for males. The rates for males and for both genders combined, but not for females, were significantly lower than the U.S. rates for all races (P < 0.05). Females had significantly lower rates of death from carcinoma of the lung and breast and significantly higher rates of death from carcinoma of the cervix and gallbladder (P < 0.05). Males had significantly lower rates of death from carcinoma of the lung, colon, and prostate, and significantly higher rates of liver carcinoma. Both genders combined had significantly lower rates of death from lung and colon carcinoma and significantly higher rates of death from stomach, liver, kidney, and gallbladder carcinoma. Geographic differences were substantial, with the Northern and Plains regions experiencing much higher mortality from lung, colon, and breast carcinoma than the Southwest region. CONCLUSIONS: Compared with the general U.S. population, Native Americans experience quite different patterns of cancer mortality. Cancer prevention and control programs should be designed specifically for this minority population.