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Biomedical subjects

B J Myers

Publications and source records attributed to B J Myers.

At least 19 recordsLinked to original sources
PubMed2001

The discovery of indoxacarb: oxadiazines as a new class of pyrazoline-type insecticides.

The evolution of the insecticidal pyrazoline moiety that was originally discovered in 1972 has led to the discovery of a new crop insecticide, indoxacarb, which is the first commercialized pyrazoline-type sodium-channel blocker. Both monocyclic and fused-tricyclic pyrazolines and pyridazines, as well as structurally related semicarbazones were examined prior to the discovery of analogous tricyclic oxadiazines which had similarly high activity as well as favorable environmental dissipation rates and low toxicity to non-target organisms. The eventual leading candidate, DPX-JW062, was originally obtained as a racemic molecule, but a chiral synthesis was developed which produces material that is 50% ee in the insecticidal (+)-S-enantiomer (DPX-MP062, indoxacarb).

Animals↗
PubMed2000

Total synthesis of (+)-amphidinolide P. [corrected].

The convergent enantiocontrolled total synthesis of the 15-membered macrolactone (-)-amphidinolide P is reported. Key transformations include a Sakurai allylation, a Stille coupling for the formation of a fully functionalized acyclic precursor, and intramolecular transesterification.

Animals↗
PubMed1994

Drug-using and nonusing women: potential for child abuse, child-rearing attitudes, social support, and affection for expected baby.

Eighty pregnant women (25 substance using, 55 nonusing) from an American prenatal clinic serving lower-income to working-class women responded to questionnaire measures of child-rearing attitudes. The drug users' primary substance of misuse was cocaine (68%), alcohol (16%), amphetamines (12%), or sedatives (4%); polydrug use was documented for 80% of the women. The two (user and nonuser) groups were not different on demographic (age, race, marital status, education, SES, source of income) or obstetrical factors (number of pregnancies, number of children). Drug-using women scored significantly higher on a measure of child abuse potential; more than half scored in the range of clinical criterion for extreme risk. As their babies were not yet born, no actual physical abuse was documented, only a higher potential for abuse. The subgroup who were both drug users and had lower social support scored higher on child abuse potential than all other subgroups. The drug users also had lower self-esteem scores than the nonusers. The two groups did not differ on measures of overall social support, authoritarian/democratic child-rearing beliefs, or affection for the expected baby.

Adult↗
PubMed1993

Social support and anxiety in pregnant drug abusers and nonusers: unexpected findings of few differences.

Drug-abusing (n = 25) and nonusing (n = 55) pregnant women from a publicly supported prenatal clinic were tested for level of social support and of pregnancy anxiety during the last half of pregnancy. Differences found between the groups were fewer than expected. Drug abusers did not differ from nonusers in overall level of social support or in Appraisal, Belonging, or Tangible subscales. Abusers were found to report lower levels of self esteem; lower self esteem was predicted by drug abuse, having more children and lower socioeconomic status. Drug abusers did not differ from nonusers in their overall feelings of pregnancy anxiety, but they did indicate higher fears for themselves and for the baby, and there was a tendency for higher depression and withdrawal.

Adolescent↗
PubMed1990

Couples with an elderly parent with Alzheimer's disease: perceptions of familial relationships.

This study examined family relationships in families with and without an elderly parent with Alzheimer's disease. Spouses (29 pairs with an Alzheimer's diseased parent; 29 pairs with a healthy elderly parent) completed questionnaires regarding their perceived relationships with each other, their parent, and one of their own children (aged 8-18). In addition, they completed surveys that inquired about feelings of burden regarding the target parent. Couples perceived a poorer relationship with parents with Alzheimer's disease when contrasted to couples who had a healthy elderly parent. In addition, wives with an Alzheimer's parent also tended to have a more negative relationship with their husbands than wives who had a healthy parent. Perceptions of burden were associated with poorer spousal relationships for wives but not husbands.

Adaptation, Psychological↗
PubMed1989

Water stress and seedling growth of two eucalypt species from contrasting habitats.

Seedlings of Eucalyptus maculata Hook (mesic environment) and E. brockwayi C.A. Gardn. (arid environment) were supplied 100, 70 or 40% of their water requirements estimated from leaf area and the water used by well-watered seedlings. Restricting water supply caused large differences in growth rates, which were related to large differences in total leaf area. There was a fivefold range of variation in number of leaves per plant, and a reduction of up to 20% in average leaf size as a consequence of restricting water supply. Eucalyptus maculata seedlings produced more dry matter than E. brockwayi seedlings, but net assimilation rate was higher in E. brockwayi seedlings. Transpiration rates were also higher in E. brockwayi than in E. maculata. Leaf expansion was analyzed as a function of water stress integral (S(Psi)), which is the cumulative integral over time of predawn water potential below a datum. The leaf area achieved at any stress level was not uniquely dependent on total S(Psi), there was a secondary effect associated with reduced leaf growth caused by previous stress. At any value of S(Psi), reductions in leaf growth of water-stressed seedlings relative to leaf growth of well-watered control seedlings were greater in E. maculata seedlings than in E. brockwayi. Treatment differences in both species showed that, within the levels of stress applied, a moderate water stress over a long period of time was more detrimental to dry matter production than a severe stress for a short time.

Journal Article↗
PubMed1988

Water stress integral-a link between short-term stress and long-term growth.

Water stress integral (S(Psi)), the cumulative integral of pre-dawn leaf water potential over any chosen period of time, was estimated from measurements of pre-dawn water potential made every two weeks in a Pinus radiata D. Don plantation near Canberra, Australia. Also measured were final length of current-season needles and annual stem basal area increment. Data were gathered over a 4-year period from a control plot, a fertilized plot, an irrigated plot, and two plots that were both fertilized and irrigated. Among years and treatments, annual basal area increment varied over a threefold range. Of this variation, 91% was accounted for by variation in S(Psi) for the entire year, during every month of which stem diameter growth occurred. Of variation in annual needle elongation, 90% was accounted for by variation in S(Psi) from late August to late February, which was the period of needle growth. In dry years, the annual value of S(Psi) in non-irrigated plots was mainly determined by soil water content, but in wet years in non-irrigated plots, and in all years in irrigated plots, it was closely correlated with tree nutrient status (r(2) = 0.81).

Journal Article↗
PubMed1987

Premenstrual tension syndrome symptom clusters. Statistical evaluation of the subsyndromes.

Premenstrual symptoms were evaluated in a group of women with severe premenstrual tension syndrome. Factor analysis was performed in order to establish the nature of symptom clusters in this sample. Similar to clinical observations reported on before, the results revealed two distinct clusters of emotional/behavioral symptoms and two of physical symptoms.

Adolescent↗
PubMed1982

Early intervention using Brazelton training with middle-class mothers and fathers of newborns.

The purpose of this study was to test the effectiveness of the Brazelton exam as a parent education tool for mothers and fathers. 42 middle-class families with firstborn, healthy, full-term infants were randomly assigned to one of three groups: father treatment, mother treatment, and control. The target parents in the treatment groups were taught to perform the Brazelton exam on their own infant, with attention being drawn to the infant's most positive interactive and physical abilities. Questionnaire and observational data were collected in the hospital and at 4 weeks postpartum. These included measures of knowledge of infant behavior, confidence in parenting ability, satisfaction with the infant, and behavior with the infant. The results showed that treatment parents scored higher in knowledge about infants, at both the early and the 4-week periods. Also, treatment fathers were more involved in caretaking with their infants at 4 weeks than were control fathers. More modest treatment effects were shown for confidence and satisfaction measures. No behavioral treatment effects were found during a 10-min observation of parent-infant interaction.

Adult↗
PubMed1975

Calcification of the bladder and papillary tumours of the bladder and ureters in gibbons (Hylobates lar) infected with Schistosoma haematobium (Iran).

Many species of nonhuman primates have been employed to find parasite-definitive host combinations which would allow for investigations on different aspects of schistosomiasis haematobia. Gibbons (Hylobates lar), exposed to moderate numbers of Schistosoma haematobium cercariae, have demonstrated some of the basic features of schistosomiasis haematobia in man. Calcification in schistosomiasis haematobia is variable. Radiologically evident calcification of the bladder was noted in one gibbon. Radio-opaque areas in the bladder corresponded to dense deposits of calcified eggs observed on histological examination. Thus, it seems, bladder calcification, thought to be a later complication of schistosomiasis, can develop fairly rapidly. One of two gibbons killed 11 months after infection had small papillary transitional cell tumours in both ureters. The other had papillary transitional cell tumours covering most of the urinary bladder surface. No invasion of muscle by tumour was present and no metastases were seen.

Animals↗