Impaired Wound Induction of 3-Deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) Synthase and Altered Stem Development in Transgenic Potato Plants Expressing a DAHP Synthase Antisense Construct.

Potato (Solanum tuberosum L.) cells were transformed with an antisense DNA construct encoding part of 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) synthase (EC 4.1.2.15), the first enzyme of the shikimate pathway, to examine the role(s) of this protein in plant growth and development. Chimeric DNA constructs contained the transcript start site, the first exon, and part of the first intron of the shkA gene in antisense or sense orientations under the control of the cauliflower mosaic virus 35S promoter. Some, but not all, of the transgenic plants expressing antisense DAHP synthase RNA showed reduced levels of wound-induced DAHP synthase enzyme activity, polypeptide, and mRNA 12 and 24 h after wounding. No alteration in the wound induction of DAHP synthase gene expression was observed in transgenic potato tubers containing the chimeric sense construct. Reduced steady-state levels of DAHP synthase mRNA were observed in stem and shoot tip tissue. Some plants with the chimeric antisense construct had reduced stem length, stem diameter, and reduced stem lignification.

Latino beliefs about diabetes.

OBJECTIVE: To describe Latino beliefs about diabetes and assess heterogeneity in beliefs across different groups. RESEARCH DESIGN AND METHODS: This study comprised a survey of 161 representative Latino adults from four diverse communities: Hartford, Connecticut; Edinburg, Texas; Guadalajara, Mexico; and rural Guatemala. A 130-item questionnaire covered causes symptoms, and treatments for diabetes. Information on demographics and acquaintanceship with someone with diabetes was also collected. The cultural consensus model was used to analyze the variation in responses to determine whether the degree of consistency within and between samples was sufficient to warrant aggregation and description as a single set of beliefs. RESULTS: Homogeneous beliefs were present within each of the four samples. Although variability in responses increased significantly from Connecticut to Guatemala (P < 0.00005), there was significant agreement between samples on the answers (P < 0.0005). Answers tended to be concordant with the biomedical description of diabetes. Greater acculturation, higher educational attainment, and higher diabetes prevalence were associated with greater cultural knowledge about diabetes. In Connecticut, greater knowledge correlated with longer mainland U.S. residency (P < 0.05). In Mexico, those with average educational attainment knew more (P < 0.05). Finally, average knowledge levels were higher in communities with greater diabetes prevalence. CONCLUSIONS: The cultural consensus model facilitated assessment of cultural beliefs regarding diabetes and diabetes management. Overall, Latino cultural beliefs about diabetes were concordant with the biomedical model. Variation in responses tended to characterize less knowledge or experience with diabetes and not different beliefs.

Iron status of inner-city elementary school children: lack of correlation between anemia and iron deficiency.

The iron status of 103 inner-city third and fourth graders was evaluated. These children had significantly lower hemoglobin concentrations and significantly higher serum ferritin concentrations than values previously reported. Mean erythrocyte protoporphyrin concentrations agree with previous results whereas mean corpuscular volume was significantly lower than in some previous studies. Though 11 children (10.7%) were anemic, only 1 anemic child had another abnormal measure of iron status. Three children (2.9%) had a low serum ferritin concentration along with another abnormal measure of iron status. Four children (3.9%) had at least two abnormal measurements of iron status without an elevated blood lead concentration. These results agree with recent observations of decreasing rates of anemia in preschool children. The poor utility of hemoglobin measures to identify iron-deficient children suggests the need for alternate screening methods, and the relatively high serum ferritin concentration suggests a trend of rising iron stores in school-age children.

Bucket-related drownings in the United States, 1984 through 1990.

The purpose of the study is to document the incidence of bucket-related drowning in the United States and to identify factors associated with this type of submersion injury. Analysis of Consumer Product Safety Commission data revealed 160 bucket-related drownings for the years 1984 through 1989, representing a mortality rate of 0.367 per 100,000 persons (younger than 2 years old) per year in the United States. Eighty-eight percent of bucket drownings occurred in toddlers aged 7 to 15 months old. Black children were six times more likely to drown in a bucket than white children of similar age (P less than .0001). Male toddlers were at significantly greater risk than females (P less than .01). A seasonal trend present in the data indicated that infants are more likely to drown in warmer than in colder months (P less than .01). States with the highest rates of bucket drowning were Vermont (2.1/100,000), Arizona (1.5/100,000), and Illinois (1.0/100,000). Through passive and active educational strategies, perhaps this fatal home injury can be prevented.

Management of the newborn with myelomeningocele: time for a decision-making process.

The relationship between time of surgical intervention and eventual outcome was examined in 110 newborns with myelomeningocele. Numerous earlier reports have cited a significant increase in mortality and morbidity associated with delay of surgery beyond 48 hours. Within the study population of infants, 52 infants (47%) had "early" surgery within the first 48 hours of life, 32 infants (29%) had "delayed" surgery between 3 and 7 days of age, 12 infants (11%) had "late" surgery between 1 week and 10 months of age, and 14 infants (13%) never had surgery by parental decision. Survival rates were similar between those with early, delayed, or late surgery as 92%, 94%, and 100%, respectively, were alive at age 10 months. Also, no significant association existed between time of surgery and development of ventriculitis, developmental delay, or worsening of paralysis. From these observations, it is concluded that there is no urgency in surgical intervention for the initial management of newborns with myelomeningocele. Rather, there is time for comprehensive discussions, counseling, and emotional support for those parents in need of a decision-making process before establishing consent for or against surgical management of their newborn.

Prospective evaluation of a risk scoring system for predicting preterm delivery in black inner city women.

Nine percent of United States births are preterm. The ability to efficiently identify women destined to deliver before term would enable obstetricians to initiate early intervention. The Papiernik-Creasy risk scoring system is being extensively applied for this purpose, without prospective validation in this country. We evaluated prospectively its ability to predict high risk women in a black inner city population, when applied once early in pregnancy. The system, based on social, past medical, and current pregnancy problems, failed to identify at-risk patients. Adjusting the score cutoff and reweighting factors with discriminate analysis did not improve the predictive value. Analysis of an additional 60 social, demographic, and medical factors failed to produce a useful alternative risk assessment tool. We suggest that risk scoring systems such as these may not be helpful in socioeconomically at-risk populations.

Knowledge and beliefs about malaria on the Pacific coastal plain of Guatemala.

Surveys of residents of the Pacific coast of Guatemala revealed a lack of knowledge and many misconceptions about the transmission and treatment of malaria, which could adversely affect malaria control measures and antimalarial therapy. Although mosquitoes are known to play an important role in malaria transmission and are thought to become infected by biting individuals with malaria, 75% of people interviewed believe that the mosquitoes can also acquire infections from contaminated water or by biting snakes and frogs. Furthermore, most residents believe that malaria can be acquired in other ways, such as by bathing too frequently or by drinking unboiled water. Although self-treatment of malaria with oral and injectable drugs purchased at stores and pharmacies is very common, less than 10% of the respondents were aware of the correct curative dose of chloroquine. Chloroquine injections are preferred to tablets and believed to be approximately three times as potent as tablets of the same concentration. Nearly two-thirds of the interviewees believed that pregnant and lactating women with malaria should avoid the use of chloroquine because it may cause a spontaneous abortion or dry up breast milk. Similar surveys of National Malaria Service workers and village malaria workers revealed higher levels of knowledge, although the village workers had many misconceptions about malaria transmission. An educational campaign directed at correcting some of these misconceptions should result in more appropriate self-treatment of malaria and greater acceptance by residents of personal protection methods and vector control and drug treatment programs.

Knowledge, beliefs, and practices in relation to malaria transmission and vector control in Guatemala.

As part of an effort to involve community members in malaria control activities, we studied knowledge, beliefs, and practices of residents of both the Pacific coastal plain and northeastern Guatemala related to malaria transmission and Anopheles albimanus control. Most residents recognized the role of mosquitoes in malaria transmission, but few knew how mosquitoes acquired their infections or understood the risk of having an untreated person in their midst. If this were more widely known, residents might put greater pressure on infected patients to seek timely and appropriate antimalarial treatment. Seventy-three percent of families owned one or more bed nets; however, even though most informants believed that bed nets help protect against malaria, the major reason for using them was to prevent nuisance mosquito bites. It is concluded that efforts should be made to promote bed net use by seeking ways to make them more affordable and by emphasizing their effectiveness as a barrier to nuisance mosquitoes. Although residents have a very positive opinion of the National Malaria Service spray teams, it is proposed that cooperation might be improved if malaria workers would emphasize the fact that house spraying reduces the numbers of nuisance mosquitoes and other pest insects, rather than focusing solely on malaria prevention, which most informants believed was less important. This study emphasizes the importance of understanding community beliefs and practices when planning or evaluating vector control activities.

A meta-analysis of condom effectiveness in reducing sexually transmitted HIV.

Before condoms can be considered as a prophylaxis for sexually transmitted human immunodeficiency virus (HIV), their efficacy must be considered. This paper reviews evidence on condom effectiveness in reducing the risk of heterosexually transmitted human HIV. A meta-analysis conducted on data from in vivo studies of HIV discordant sexual partners is used to estimate the protective effect of condoms. Although contraceptive research indicates that condoms are 87% effective in preventing pregnancy, results of HIV transmission studies indicate that condoms may reduce risk of HIV infection by approximately 69%. Thus, efficacy may be much lower than commonly assumed, although results should be viewed tentatively due to design limitations in the original studies.

Personal preferences and ethnic variations among Anglo and Hispanic breast and bottle feeders.

The preferences of Spanish-speaking Hispanics and English-speaking Anglos for breast and bottle feeding were evaluated using marketing research techniques. Preliminary interviews with 55 mothers conducted within the first 48 hr post-partum elicited a list of verbatim responses regarding the positive and negative aspects of both feeding methods. An additional 195 women rank-ordered the most frequently mentioned statements in terms of their preference for each. Socio-demographic data on the mothers were analyzed with chi-square analysis and discriminant analysis. Multidimensional scaling was used to assess the preferred characteristics of breast and bottle feeding. Results indicated that most mothers prefer a method of infant feeding that allows the mother to be 'closer to her baby' and allows the baby to 'grow up healthier.' Bottle feeders perceived bottle feeding to be superior because it insured that baby would be 'full and satisfied' and would 'get all the vitamins and nutrients it needed,' especially when 'mother was not eating right" or was 'on medications.' Analysis of cultural preference patterns revealed that there exists a strong culture pattern or preference for breast feeding and its characteristics among Anglos. In contrast, the Hispanics show no clear preference for either breast or bottle feeding.

Qualities of an ideal volunteer community malaria worker: a comparison of the opinions of community residents and national malaria service staff.

Since the late 1950s, most malaria surveillance and treatment in rural areas of Latin America has been carried out by networks of unpaid community malaria workers, known as Volunteer Collaborators, who are selected and supervised by staff of the national malaria services (NMSs) in each country. In spite of the free and readily accessible antimalarial treatment available at these Volunteer Collaborator posts, many residents continue to seek treatment elsewhere and in most cases take doses of antimalarials that are insufficient to cure their infections. To identify ways in which the Volunteer Collaborator Network could be made more attractive to residents and to improve the process of selection of new workers, we asked community residents and Guatemalan NMS workers to rank order, according to their importance, 11 qualities or characteristics of an 'ideal' volunteer malaria worker. Community residents preferred someone who is available to take care of patients at all times of the day, is a responsible person, and has a general knowledge of medicine. No significant differences were noted in the rank orders of male and female residents or literate and illiterate residents. National Malaria Service workers also preferred someone who takes care of patients at all times of the day, even when busy. In addition, they wanted individuals who recognize the importance of their work as a Volunteer Collaborator, but choosing volunteers who had a general knowledge of medicine was not important. By modifying the procedures used to select Volunteer Collaborators so as to identify candidates with the qualities preferred by residents, it should be possible to increase acceptance and improve the performance of these volunteer workers.

Assessing rater performance without a "gold standard" using consensus theory.

This study illustrates the use of consensus theory to assess the diagnostic performances of raters and to estimate case diagnoses in the absence of a criterion or "gold" standard. A description is provided of how consensus theory "pools" information provided by raters, estimating rater competencies and differentially weighting their responses. Although the model assumes that raters respond without bias (i.e., sensitivity = specificity), a Monte Carlo simulation with 1,200 data sets shows that model estimates appear to be robust even with bias. The model is illustrated on a set of elbow radiographs, and consensus-model estimates are compared with those obtained from follow-up data. Results indicate that with high rater competencies, the model retrieves accurate estimates of competency and case diagnoses even when raters' responses are biased.

Consensus theory model of AIDS/SIDA beliefs in four Latino populations.

To describe Latino beliefs about AIDS (SIDA), Latino adults were sampled at two U.S. sites (Connecticut and Texas) and two international sites (Mexico and Guatemala). A 125-item questionnaire covered risk factors, symptoms, treatments, and sequellae of AIDS. The cultural consensus model was used to determine the cultural beliefs for each sample. Responses from 161 people indicated that a single set of beliefs was present at each site and that beliefs were shared across sites. Comparison of answers between samples indicated high agreement (p < .0007). The proportion of shared beliefs, however, decreased significantly between samples: .68 in Connecticut, .60 in Texas, .51 in Mexico, and .41 in Guatemala (p < .05). The proportion of positive answers similarly decreased from Connecticut to Guatemala (p < .001). Beliefs were stronger and more detailed in the higher prevalence areas. Furthermore, Latino beliefs tended to converge on biomedical beliefs about the disease.

Predictors of lead stores in male veterans.

Thirty-two male veterans participated in a study to determine cumulative lead exposure in an urban population. Subjects were chosen on the basis of blood pressure status in order to attempt to compare lead exposure between patients with and without hypertension. Patients currently enrolled in hypertension clinic and on treatment were recruited and matched with controls for age, race, and socioeconomic status. Each subject underwent provocative chelation via slow intravenous infusion of CaNa2 EDTA and 6-h urinary lead measurement and completed an interviewer-administered questionnaire. Twenty blacks and 12 whites participated, with a median age of 52 years (range: 27 to 72). Urinary lead excretion ranged from below detection limits to frankly toxic levels in an individual with heavy moonshine ingestion. Lead levels were higher than reported in other non-workplace populations. The distribution of lead values was skewed, as expected, with a median excretion of 75 mcg lead/6 h (corresponding to a median 24 degrees post-chelation urinary lead excretion of 286 mcg) and modal values between 50 and 75 micrograms lead. Levels of 95 mcg lead/6 h (corresponding to 24 degrees levels of 333 mcg lead) and above were considered "high" (N = 11) and the remainder were "low" (N = 21). Among those able to recall various characteristics of their first childhood dwellings, the presence of flaking paint in a multiple family dwelling was strongly associated with "high" lead excretion (X2 = 9.32, p = 0.009). Hypertensives excreted slightly more lead than nonhypertensives, although the difference was not statistically significant in this small sample. Lead excretion was not associated with current (treated) blood pressure determinations among hypertensives. However, lead excretion was associated with systolic pressure as recorded on entry to the hypertension clinic (N = 21, R2 = 0.24, p = 0.03).

The effect of blood lead on blood pressure in children.

The effect of elevated blood lead levels on the blood pressure of children has not been clearly described. In order to define this association better, we conducted a cross-sectional study, evaluating the association between lead and high blood pressure. Using a Dinamap monitor to measure blood pressures, blood pressures and blood lead levels were measured in 149 children (ages 1-10 years) receiving medical care at the General Medical and Lead Poisoning Clinics at Children's Hospital of Philadelphia. Blood lead levels ranged from 7 to 70 mg/dL with a mean of 27 mg/dL. The mean systolic blood pressure was 108 mmHg and the mean diastolic reading was 63 mmHg. Higher systolic blood pressure was significantly correlated with increased weight, age, and height. Diastolic pressure was significantly associated with weight and height. There was a small, negative correlation between blood lead levels and systolic blood pressure, and a positive but insignificant correlation between lead levels and diastolic blood pressure. Our study population had both higher mean lead levels and a higher prevalence of hypertension than is true of the U.S. population as a whole. We concluded that elevated blood lead levels are not associated with elevated blood pressure in children.

Factors affecting Agrobacterium tumefaciens-mediated transformation of peppermint.

Substantial improvement in peppermint (Mentha x piperita L. var. Black Mitcham) genetic transformation has been achieved so that the frequency of transgenic plants regenerated (percent of leaf explants that produced transformed plants) was 20-fold greater than with the original protocol. Essential modifications were made to conditions for Agrobacterium tumefaciens co-cultivation that enhanced infection, and for selection of transformed cells and propagules during regeneration. A systematic evaluation of co-cultivation parameters established that deletion of coconut water from the co-cultivation medium resulted in substantially increased transient ß-Glucuronidase (GUS) activity, in both the frequency of explants expressing gusA and the number of GUS foci per explant (>700 explants). Co-cultivation on a tobacco cell feeder layer also enhanced A. tumefaciens infection. Enhanced transformation efficiencies were further facilitated by increased selection pressure mediated by higher concentrations of kanamycin in the medium during shoot induction, regeneration, and rooting: from 20 to 50 mg/l in shoot induction/regeneration medium and from 15 to 30 mg/l in rooting medium. Raising the concentration of kanamycin in media substantially lowered the number of "escapes" without significant reduction in plant regeneration. These modifications to the protocol yielded an average transformation frequency of about 20% (>2000 explants) based on expression of GUS activity or the tobacco antifungal protein, osmotin, in transgenic plants. Genetic transformation of peppermint has been enhanced to the extent that biotechnology is a viable alternative to plant breeding and clonal selection for improvement of this crop.

Transgenic peppermint (Mentha×piperita L.) plants obtained by cocultivation with Agrobacterium tumefaciens.

The first transgenic peppermint (Mentha×piperita L. cultivar Black Mitcham) plants have been obtained by Agrobacterium-mediated transformation by cocultivation with morphogenically responsive leaf explants. Basal leaf explants with petioles, from leaves closest to the apex of in-vitro-culture-maintained shoots (5 cm), exhibited optimal shoot organogenetic responsiveness on medium supplemented with thidiazuron (8.4 µM). Shoot formation occurred at sites of excision on the leaf blade and petiole either directly from cells of the explant or via a primary callus. Analyses of transient GUS activity data indicated that DNA delivery by microprojectile bombardment was more effective than Agrobacterium infection. However, no transgenic plants were obtained from over 22,000 leaf explants after particle bombardment. Cocultivation of leaf explants with Agrobacterium strain EHA 105 and kanamycin selection produced transgenic plants. Greater transient and stable -glucuronidase (GUS) activities were detected in explants or propagules transformed with the construct where gusA was driven by the pBISN1 promoter rather than a CaMV 35S promoter. Eight plants were subsequently regenerated and verified as transgenic based on detection of the nptII transgene by PCR and Southern blot analyses. The Southern analyses indicated that the plants were derived from eight unique transformation events. All transgenic plants appeared morphologically normal. Analyses of GUS activities in leaves sampled from different portions of these transgenic plants, 10 months after transfer to the greenhouse, indicated that six out of the eight original regenerants were uniformly transformed, i.e., did not exhibit chimeric sectors.

Acculturation and compliance with medical therapy.

Lack of compliance with medical therapy is a major clinical problem. We undertook a study to determine whether degree of acculturation to mainland U.S. culture was predictive of compliance in Puerto Rican families having a child with asthma. A questionnaire was administered to parents of Puerto Rican asthmatic children attending an asthma clinic and taking oral theophylline as part of their medical management. The questionnaire included items concerning medical, socioeconomic, and cultural variables, as well as a standardized instrument devised to measure degree of acculturation. Compliance was measured by a serum theophylline level obtained at the time of the visit. Families were divided into compliant (n = 15) and noncompliant (n = 13) groups based on their child's serum theophylline determination. There was a significant difference in mean acculturation scores between compliant and noncompliant groups (p = .008). Those in the complaint group had scores indicative of a style of acculturation that integrated aspects of both "Anglo" and Puerto Rican lifestyles. Those in the noncompliant group had scores indicative of a less acculturated lifestyle. The findings of this study show that degree of acculturation is a predictor of compliance with medical therapy in mainland Puerto Ricans. Additional studies with other cultural groups are needed, as well as other studies incorporating acculturation into a multivariate model of compliance.

An epidemiological description of a folk illness: a study of empacho in Guatemala.

Although anthropologists have provided descriptions of many folk illnesses, few have systematically evaluated their prevalence and determined who is at greatest risk for acquiring them. This report attempts to provide a systematic description of the folk illness empacho including the symptoms that define it. Illness prevalence was estimated and subpopulations at greatest risk were identified from illness histories collected from a random sample of households in rural Guatemala. Empacho was found to constitute a distinct cluster of symptoms: diarrhea, vomiting, headache, and lack of appetite. It differed from other gastrointestinal illnesses in that headaches were more likely and stomachaches were less likely to be reported. Empacho was highly prevalent and occurred in adults and children. Further, results showed that although empacho was frequently diagnosed by residents, folk healers were rarely consulted for any illness. Nevertheless, a strong association exists between a household diagnosis of empacho and the use of folk healers by those households (p less than .001).

Empacho in four Latino groups: a study of intra- and inter-cultural variation in beliefs.

It is usually impossible to know if reported differences between cultures are due to cultural differences or due to a difference in the methods used to study the cultures. This paper describes a collaborative, multisite study using a shared methodology to study intra- and inter-cultural variation in beliefs. A series of standard interview schedules were used to study Latin American beliefs about empacho in Guatemala, Mexico, and in the United States (Mexican-Americans and Puerto Ricans). Results showed consistency in beliefs about empacho both within and between the four samples.