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Biomedical subjects

M E Wilson

Publications and source records attributed to M E Wilson.

At least 217 records · Page 12Linked to original sources
PubMed1994

Gun violence among youth and the pediatrician's role in primary prevention.

Adolescence is a developmental stage characterized by high rates of violent behavior. Increasingly, violent injury is involving preadolescent children. Evidence suggests that the availability of guns increases the lethality of violent acts. Because guns are ubiquitous in the United States and integral to the current epidemic of youth violence, pediatricians should participate in primary prevention of firearm injuries. Efforts should begin long before children reach adolescence. Pediatricians should: (1) Encourage parents to remove guns from the home, or at a minimum to keep guns unloaded and locked up; (2) Advise parents to limit viewing of gun violence in the media, and playing with toy guns and video games that involve shooting; (3) Be alert for early indicators of aggressive behavior; and (4) Become outspoken advocates for laws that restrict gun availability.

Adolescent↗
PubMed1994

Pediatrician interview style and mothers' disclosure of psychosocial issues.

OBJECTIVE: Primary care pediatricians play an important role in the detection, diagnosis, treatment, and referral of children with mental health problems. Some parents, however, are reluctant to discuss behavioral and emotional symptoms with their child's pediatrician. Studies of patient-physician communication suggest that specific aspects of pediatrician interview style (asking questions about psychosocial issues, making supportive statements, and listening attentively) increase disclosure of sensitive information. We hypothesized that disclosures of parent and child psychosocial problems would be more likely to occur during visits when pediatricians used these techniques. DESIGN: Cross-sectional analysis of a systematic sample of pediatric primary care visits. POPULATION: Two hundred thirty-four children ages 6 months to 14 years and their mothers or female guardians attending an inner-city hospital-based pediatric primary care clinic; 52 physicians in their second or third year of pediatric residency training. METHODS: Visits audiotaped and dialogue coded using the Roter Interactional Analysis System. Independent variables included counts of pediatrician utterances in the following categories: (a) questions about psychosocial issues, (b) statements of support and reassurance, and (c) statements indicating sympathetic and attentive listening. Dependent variables were the disclosure of information about: (a) parental medical or emotional impairment, (b) family disruption, (c) use of physical punishment, and (d) aggressive or overactive child behavior. RESULTS: Use of psychosocially oriented interviewing techniques was associated with a greater likelihood of disclosure for all four of the topic areas studied. Odds ratios for disclosure, adjusted for parental concerns and child age, ranged from 1.09 to 1.22 depending on the interview technique and outcome involved. Positive associations were observed both for topics raised primarily in response to pediatrician questions (family and parent problems) and for topics raised primarily by mothers (behavior and punishment). CONCLUSIONS: Three simple communication skills were associated with disclosure of specific concerns relevant to child mental health. Training pediatricians to use these skills would help to better detect and diagnose children's mental health problems.

Adolescent↗
PubMed1993

Bacon therapy and furuncular myiasis.

OBJECTIVE: To evaluate a simple, noninvasive method for removing fly larvae from patients with furuncular myiasis. DESIGN: Case series. SETTING: Ambulatory office of a tertiary care center. PATIENTS: Three patients who presented with Dermatobia hominis infestation. INTERVENTION: The patients with D hominis infestation were treated with the application of bacon fat over the larval apertures. MAIN OUTCOME MEASURE: Removal of intact larvae. RESULTS: Within 3 hours of the application of bacon, the larvae had migrated sufficiently far out of the skin to be removed with tweezers. Ten larvae were removed with this method. There were no treatment failures or complications. CONCLUSIONS: Furuncular myiasis will be seen more frequently in temperate areas as individuals travel to endemic areas. We describe the clinical characteristics of myiasis and a simple method of treatment that permits rapid diagnosis and cure.

Animals↗
PubMed1993

The effect of ongoing protein synthesis on the steady state levels of Gp63 RNAs in Leishmania chagasi.

G63, the major surface glycoprotein of Leishmania chagasi promastigotes, increases 11-fold in amount as promastigotes grow from logarithmic to stationary phase. Transcripts from three different classes of gp63 genes are differentially expressed during this development (Ramamoorthy, R., Donelson, J. E., Paetz, K. E., Maybodi, M., Roberts, S. P., and Wilson, M. E. (1992) J. Biol. Chem. 267, 1888-1895). We studied the effect of protein synthesis inhibitors on gp63 mRNAs. The steady state level of log class gp63 RNA, expressed primarily in logarithmic phase promastigotes, increased 16.5-fold after incubation in cycloheximide. A similar increase in log gp63 RNAs was caused by inhibitors that block different steps in translation. In contrast, the levels of stationary class gp63 RNA, expressed in stationary phase parasites, and constitutive class gp63 RNA, expressed throughout promastigote growth, increased only 2.3- and 1.5-fold, respectively. The latter was not statistically significant. Nuclear run-on assays showed that the cycloheximide effect was not due to an increased rate of transcription. However, the t1/2 of log RNAs was prolonged 6.5-fold after incubation in cycloheximide, in contrast to a 1.7-fold increase in the t1/2 of ATPase RNA, suggesting that cycloheximide specifically stabilizes log gp63 mRNAs. Thus, a highly labile negative regulatory protein, such as an RNase, may specifically target log gp63 RNAs for degradation.

Animals↗
PubMed1993

Relationship between social factors and pituitary-adrenocortical activity in female rhesus monkeys (Macaca mulatta).

Psychosocial stress in humans has been related to the occurrence or progression of certain diseases and a positive social environment has been shown, in some cases, to ameliorate this effect. In many experimental studies changes in serum cortisol levels have been used as an endocrine-defined stress response, however, the variation in this measure under unchanging conditions in socially housed animals is not well documented. The present study was designed to examine the relationship between specific social behaviors and concentrations of serum cortisol in female rhesus monkeys. Subjects were members of one of two social groups. One was an established long-term (8 years) group with members which had from one to many kin, while the second was a group formed 5 months prior to the onset of the present study composed of initially unfamiliar animals. Blood samples were collected weekly and a total of 16 hr of behavioral data was collected on each subject. For purposes of analyses, the year-long study was organized according to calendar quarters (3 months) with cortisol concentrations averaged and behavioral categories cumulated. When regression techniques were applied, it is of note that neither group nor dominance rank was a predictor of cortisol levels. However, when a correlation analysis was applied to each group separately to assess the effect of dominance rank, rank significantly correlated with cortisol levels in the established but not in the recently formed group. In each quarter, analyses revealed behavioral categories which combined to account for a significant proportion of the variance in cortisol levels, but these behaviors were not identical over the four quarters. For three of the four quarters analyzed, and for the year as a whole, an affiliative behavioral category was predictive of cortisol levels in addition to agonistic behavioral categories. These data suggest that cortisol levels are influenced by not only negative interactions, such as receiving bites, but also by positive interactions such as receiving grooms. Results also showed that reconciliatory behaviors occurred significantly more frequently following dyadic agonistic episodes in the recently formed versus the long-term group. The higher rate of reconciliatory behaviors exhibited by the recently formed group may account for the lack of a dominance rank/cortisol relationship.

Aggression↗
PubMed1993

Sequence diversity and organization of the msp gene family encoding gp63 of Leishmania chagasi.

During in vitro growth Leishmania chagasi promastigotes differentially express 3 classes of RNAs encoding the major surface protease (MSP) gp63 that can be distinguished by their unique 3' untranslated regions. Here we show that the three classes (logarithmic-specific, stationary-specific and constitutively expressed) are encoded by a family of at least 4 tandem stationary genes (mspS2, mspS1, mspS3 and mspS5) followed by twelve or more logarithmic genes (mspL genes), one constitutive gene (mspC) and a final stationary gene (mspS4). Some of the stationary genes can be distinguished from each other by groups of nucleotide differences within the coding regions that result in localized amino acid differences. Northern blots confirm that RNAs from the individual stationary genes are present in stationary, but not logarithmic, phase promastigotes. Western blots using sera directed against synthetic peptides indicate that correspondingly heterogeneous gp63 proteins are expressed in L. chagasi promastigotes. A 200-bp region upstream of all three gp63 gene classes is conserved except for a variable number of 6-bp repeats. Downstream of the gp63 coding regions are highly conserved, class-specific sequences that include the 3' untranslated regions and extend past the polyadenylation site for 65 bp (mspL), 345 bp (mspC) or 2.8 kb (mspS). These sequence features flanking the msp coding regions are likely important in the growth phase-specific expression of the three gp63 RNA classes.

Amino Acid Sequence↗
PubMed1993

An alternative method for rapid preparation of 99Tcm-sestamibi.

The availability of 99Tcm-sestamibi is limited, especially in emergency cases due to the time-consuming preparation procedure that requires a 10-min boiling water bath and a 30-min radiochemical purity (RCP) analysis. These two restrictions have been surmounted by the combined use of a microwave oven heating method and a minipaper chromatography system. However, use of the microwave oven heating method presents some potential problems: (1) technical error in setting the microwave oven heating time and power setting; (2) ejection of the rubber septum if the vial is not evacuated; (3) breakage of the vial during the microwave heating process; (4) inconsistent and inhomogeneous microwave heating; (5) reevaluation process required for use of a different type of microwave oven. Although a 1-min boiling water bath time is sufficient to provide an acceptable RCP for 99Tcm-sestamibi, additional time is required to heat the water to a boiling state. An instant hot water machine was evaluated for possible replacement of the microwave heating method. Three millilitres of 5500 MBq (150 mCi) 99Tcm was added to a Cardiolite kit and then placed in a 150-ml insulated beaker filled with hot water (86.2 +/- 1.9 degrees C, n = 45) from an instant hot water machine. A minipaper chromatography system was used to determine the RCP of samples after 1, 1.5, 2, 3, 4 and 5 min incubation periods. Our results show that 2 min was the shortest incubation time that yielded an acceptable RCP of 94.7 +/- 0.4% (n = 60) over the 24 h evaluation time. The use of an instant hot water machine not only avoids those problems associated with the microwave heating method, but also provides a rapid, efficient and relatively simple option for preparation of 99Tcm-sestamibi.

Humans↗
PubMed1993

Orotracheal intubation in patients with potential cervical spine injuries. An indication for the gum elastic bougie.

The conditions for emergency tracheal intubation of patients with cervical spine injury were simulated in 157 patients during induction of anaesthesia for routine surgery. The view of the larynx obtained during laryngoscopy with the head in the optimum intubating position was compared with that obtained when manual in-line stabilisation of the cervical spine and cricoid pressure were used. During laryngoscopy with cervical stabilisation, the view of the larynx was reduced in 45% of patients, and in 22% of patients nothing was visible beyond the epiglottis. To assess the ease of intubation with the neck stabilised and with cricoid pressure applied, patients were randomised to either direct visual intubation (n = 79), or intubation aided by a gum elastic bougie (n = 78). The median time taken for visual intubation was 20 s, but in six patients intubation took over 45 s. In addition, five patients in this group could not be directly intubated. Using the gum elastic bougie all patients, including the failures from the visual group, were intubated within 45 s (median 25 s). We recommend the gum elastic bougie as an aid to intubating the patient with suspected cervical spine injury, particularly when the glottis is not immediately visible.

Cervical Vertebrae↗
PubMed1993

Activation of serum complement by polysaccharide-containing antigens of Porphyromonas gingivalis.

We previously reported that hot aqueous phenol extraction of Porphyromonas gingivalis yields a preparation containing both lipopolysaccharide (LPS) and an antigenically distinct capsular polysaccharide (PS). In the present study, we examined the capacity of phenol-water extracts from a number of strains of P. gingivalis to activate human serum complement. Anticomplementary activity of extracts from two invasive and two noninvasive strains of P. gingivalis was assessed in a sheep erythrocyte hemolytic assay and in an alternative pathway-selective rabbit erythrocyte hemolytic assay. In the sheep erythrocyte assay, extracts from noninvasive strains were found to exhibit greater anticomplementary activity than extracts derived from invasive strains. A phenol-water extract from invasive strain ATCC 53977 was further resolved into its LPS and PS fractions. Whereas isolated LPS from this strain exhibited strong anticomplementary activity, the PS fraction was only weakly active. Phenol-water extracts from three of four strains were found to be potent activators of the alternative pathway, with extracts from the two noninvasive strains being most active. The extract from the remaining strain (ATCC 53977) was a poor activator of the alternative pathway. Further analysis of this extract revealed, however, that the LPS fraction was a potent activator of the alternative pathway, although the PS fraction exhibited negligible activity. The results of this study indicate that phenol-water extracts of invasive and noninvasive strains of P. gingivalis differ in their respective anticomplementary activities, with invasive strains being less active. Although extracts from both invasive and noninvasive strains activated the alternative pathway, this activity appears to be attributable to the LPS, rather than the PS, component.

Antigens, Bacterial↗
PubMed1993

Oestradiol negative feedback inhibition on LH secretion during lactation is prolonged in adolescent primiparous rhesus monkeys.

Lactational infertility in rhesus monkeys is significantly prolonged in adolescent primiparous compared with adult multiparous mothers. In order to determine if this longer period of infertility for young mothers is the result of a greater sensitivity to nursing-induced inhibition of LH release either by enhanced oestradiol negative feedback or a direct non-gonadally mediated suppression, the effects of periodic administration of oestradiol on serum LH concentrations in nursing ovariectomized adolescent primiparous (Prp; n = 5) and adult multiparous (Mlt; n = 7) mothers was assessed. Females were treated every 5-6 weeks with a 21-day time-release capsule of oestradiol which produced serum concentrations of approximately 250, 90 and 45 pmol/l by +6, +13 and +20 days after treatment. Thus, the design permitted assessment of LH and prolactin concentrations under a regime of 21 days of decreasing oestradiol levels followed by 2-3 weeks of no oestradiol treatment. Females were studied from week 3 to week 42 post partum and oestradiol treatment occurred during weeks 5, 11, 21, 26, 31, 36 and 41. Behavioural observations indicated that the amount of time mothers nursed their offspring decreased in a similar fashion throughout the lactational period for both Prp and Mlt females. LH concentrations under the 'no oestradiol' conditions progressively increased throughout lactation reaching maximum levels by week 36 post partum in a similar manner for both Prp and Mlt mothers. These data suggest that differences in fertility between adolescent and adult nursing mothers observed previously cannot be attributed to a difference in a direct non-gonadally-mediated affect on LH. With respect to oestradiol negative feedback inhibition of LH, oestradiol treatment effectively suppressed serum LH concentrations at all points during lactation up to week 31, at which time LH concentrations were maximally suppressed in both Prp and Mlt mothers at +6 days after treatment but by day +13 LH values were significantly higher in Mlt females. After oestradiol treatment during week 36, LH values were again maximally suppressed on day +6 in Prp females but not in Mlt females. However, the response of serum LH after oestradiol treatment during week 41 was similar between Prp and Mlt females at all sampling points.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

The amplitude of nocturnal melatonin concentrations is not decreased by oestradiol and does not alter reproductive function in adolescent or adult female rhesus monkeys.

Nocturnal concentrations of melatonin in serum decline significantly with advancing pubertal development in both children and non-human primates and elevated levels may be associated with anovulation in adults. Three studies, using female rhesus monkeys, were performed to determine whether (1) the decline in nocturnal melatonin concentrations in adolescents was due to maturational increases in serum oestradiol, (2) the experimental elevation in nocturnal melatonin would delay the normal progression of puberty in post-menarchial monkeys, and (3) the experimental elevation in nocturnal melatonin would disrupt normal ovulatory function in adults. In experiment 1, juvenile female rhesus monkeys, housed indoors in a fixed photoperiod (12 h light:12 h darkness), were assigned randomly to one of two treatment groups: ovariectomized with no replacement therapy (control; n = 4) or ovariectomized with oestradiol replacement therapy maintaining oestradiol at approximately 90 pmol/l (treated; n = 8). Twenty-four hour as well as daytime serum samples were collected from 19 to 35 months of age. Nocturnal melatonin concentrations declined significantly in all females with advancing chronological age and this change was unaffected by oestradiol treatment. The decline in nocturnal melatonin concentrations occurred, on average, 2.0 +/- 0.2 months after the initial rise in serum LH in control females and 6.0 +/- 0.8 months in treated females. Furthermore, this decline in night-time melatonin was not related to significant developmental changes in body weight. In experiment 2, control (n = 6) and melatonin-treated (treated; n = 6) adolescent female monkeys were studied from -30 to +105 days from menarche. Beginning at 45 days following menarche, treated females received 30 days of nocturnal melatonin infusion to elevate levels to prepubertal values. Developmental changes in perineal swelling and coloration as well as serum oestradiol and insulin-like growth factor-I (IGF-I) were compared with values observed during the 45-day pretreatment and 30-day post-treatment conditions as well as with those observed in control females. Despite a significant elevation in nightly melatonin levels for the 30-day period in treated females, developmental changes in oestradiol, IGF-I, and perineal coloration and swelling were not different compared with the control females. In experiment 3, adult females were given melatonin nightly beginning on the first day of menses following an ovulatory cycle and treatment was continued for 45 days or until the next menstruation occurred. Melatonin was elevated to supraphysiological levels every night throughout the treatment period.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Constant low-dose oestradiol replacement accelerates skeletal maturation and growth in ovariectomized adolescent rhesus monkeys.

The effects of oestradiol (OE2) on adolescent growth in female rhesus monkeys were evaluated by testing the hypothesis that, upon removal of the ovary, the increase in growth normally seen at the time of puberty would be abolished and that treatment with OE2 would restore it. Juvenile monkeys (n = 12) were ovariectomized and were given either an OE2-bearing silicone elastomer capsule implanted subcutaneously to simulate mid-pubertal concentrations ('treated =', n = 8) or no steroid treatment ('control =', n = 4). Females were studied from 18 to 42 months of age which, in intact females, typically encompasses the prepubertal period to the occurrence of first ovulation. Over the whole period, growth in body weight, crown-rump (CR) length and tibia length for control females were less than the 95% confidence limits of females treated with OE2. However, significant spurts of growth in both CR and tibia length occurred in the control as well as treated animals, although the peak velocities were somewhat lower for non-OE2-treated animals. Peak growth velocities occurred at an earlier chronological age in treated females, although at the same degree of skeletal maturity as found in control females. Skeletal maturity was significantly advanced in treated females from 27 months onward. Serum concentrations of nocturnal GH increased significantly with advancing age in both groups, with greater increases observed in treated females. Serum concentrations of IGF-I were higher in treated females until some 30 months of age, at which point concentrations increased in a similar fashion in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗