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Biomedical subjects

J Hoffman

Publications and source records attributed to J Hoffman.

At least 163 records · Page 9Linked to original sources
PubMed1987

The social ecology and early parenting of Caucasian adolescent mothers.

Social characteristics, maternal behaviors, and the home environments of Caucasian adolescent and nonadolescent mothers were investigated in a sample of 50 primiparous low- and middle-class women and their 4-month-old infants. The mothers were interviewed about their child-care network and about stressful life events that may have occurred since the infant's birth. The HOME inventory was completed and videotapes of 2 hours of home observations were coded to assess maternal proximity, verbalizations, activity, and physical contact with the infant. Interview data indicated that adolescent mothers relied more frequently on other teenagers and other network members for help in child care than nonadolescent mothers. In addition, they also received more frequent support from their mothers and less frequent help from their partner's and partner's mother and siblings than nonadolescent mothers. During the home visit, they were less verbal with their infants and scored significantly lower on the Responsiveness and Maternal Involvement subscales as well as on the total HOME inventory; these results were replicated on subgroups matched for socioeconomic status, emphasizing the unique social context and parenting practices of teenage mothers.

Adolescent↗
PubMed1986

Immunologic activity of lipopolysaccharides released from macrophages after the uptake of intact E. coli in vitro.

Lipopolysaccharides (LPS) have been isolated from culture supernatants and from cell lysates after the in vitro phagocytosis of E. coli by murine macrophages. By using E. coli radiolabeled specifically in the LPS component with [3H]galactose, our studies have shown that the macrophage-"processed" LPS is enhanced with respect to its immunostimulatory activity in comparison with control phenol-water-extracted LPS. As assessed by its ability to induce interleukin 1 production in naive macrophages or proliferation in cultures of murine splenocytes, the macrophage-processed LPS is between 10- and 100-fold greater in specific activity. Evidence is presented for both structural and chemical alterations in the LPS macromolecule.

Adjuvants, Immunologic↗
PubMed1986

The effects of vagotomy on compensatory ovarian hypertrophy and follicular activation after unilateral ovariectomy.

Following unilateral ovariectomy in the rat, the remaining ovary undergoes rapid compensatory changes including an increase in the number of antral follicles (follicular activation) and an increase in ovarian weight (compensatory ovarian hypertrophy). The ovary is innervated by the vagus nerve (Burden et al., 1983). In the present study, the effects of right and left cervical vagotomy and abdominal vagotomy on follicular activation and compensatory ovarian hypertrophy in the remaining right or left ovary were compared 15 days after unilateral ovariectomy. Neither right nor left cervical vagotomy affected compensatory ovarian hypertrophy of the right or left ovaries but abdominal vagotomy depressed compensatory ovarian hypertrophy in both the right and left ovaries. Left cervical vagotomy did not inhibit follicular activation, but right cervical vagotomy prevented follicular activation in the right but not left ovary. Also, abdominal vagotomy inhibited follicular activation in the right but not the left ovary. In animals with both ovaries which were subjected to the left or right cervical vagotomy or abdominal vagotomy follicular counts in both right and left ovaries were similar. Collectively, these data indicate that the vagus nerve participates in follicular activation after unilateral ovariectomy. The data also indicate that the right ovary is more dependent on vagal influences for follicular activation than the left ovary.

Animals↗
PubMed1986

Adriamycin chemotherapy for malignant mixed mesodermal tumor of the ovary. A Gynecologic Oncology Group Study.

Malignant mixed mesodermal tumor (MMMT) of the ovary is a rare, but usually fatal, cancer for which there exists no proven postsurgical therapy. The Gynecologic Oncology Group has evaluated adriamycin in this disease at a dose of 75/m2. Among 10 evaluable cases with measurable disease there was one partial response and no complete responses. Of 21 cases with nonmeasurable tumor four remain clinically free of cancer from 2 to 45 months. There were two treatment-related deaths. We conclude that adriamycin alone as first-line chemotherapy in patients with MMMT of the ovary is not sufficiently active to be clinically useful.

Doxorubicin↗
PubMed1986

The effect of naproxen on acute mountain sickness and vascular responses to hypoxia.

The role of prostaglandins in the pathogenesis of acute mountain sickness and two hypoxia-induced vascular responses was evaluated using the cyclooxygenase inhibitor naproxen. Eleven men spent 24 hours at sea level, followed by 34 hours of decompression to 428 mm Hg while receiving naproxen (N), 250 mg twice daily or placebo (P) in a double-blind crossover trial. Serum naproxen levels measured by high pressure liquid chromatography were not changed by hypoxia. The severity of acute mountain sickness (AMS) by the Environmental Symptom Questionnaire scores and observer assessment were unaffected by drug treatment. Retinal artery diameter measured from projected fundus photographs was increased after 27 hours at altitude (11.4 +/- .5 mm) vs. sea level (9.4 +/- .5 mm, p less than 0.05) during both trials. Upright mean arterial pressure fell after 6 hours at altitude (79 +/- 3 mm Hg during N and P vs. 92 +/- 3 at sea level, p less than 0.01). Minute ventilation, end expiratory alveolar PO2 and PCO2 did not differ between drug trials. This study suggests vasodilating prostaglandins do not have a major role in the genesis of AMS, hypoxia-induced retinal vasodilatation, or postural blood pressure responses in man.

Acute Disease↗
PubMed1986

Maternal and environmental factors affecting developmental outcome of infants of adolescent mothers.

The effect of maternal and environmental factors on the developmental outcome of infants with low medical risk born to adolescent and non-adolescent, primiparous, Caucasian mothers was studied. Twenty-one were adolescent mothers (less than or equal to 17 years of age) and 21 were non-adolescent (21-29 years of age). Assessment of child care support, life stress, and home environment were carried out at 4 months. Infants were examined at 8 months, and child care support and life stress were reassessed. Adolescent mothers reported less child care support at both 4 and 8 months and more life stress at 8 months than non-adolescent mothers. Adolescent mothers were also found to be less responsive, used restriction and punishment more often, and were less involved with their infants during the home observation. Infants of adolescent mothers had lower Bayley Mental Development Indices at 8 months. A theoretical model, whereby the mother's age, education, and socioeconomic status (SES) were conducive to less optimal child care support and life stress, which in turn affected the infant's cognitive status, was supported by this data. Thus, within a low medical risk population, we have documented the significant role of maternal and environmental factors in determining the infant's cognitive status.

Adolescent↗
PubMed1986

Corticosteroids in COPD. A clinical trial and reassessment of the literature.

A placebo-controlled, double-blind cross-over trial was conducted to assess whether 16 men with chronic obstructive pulmonary disease (COPD) would benefit from orally taken corticosteroids. Two weeks of treatment with 40 mg of prednisone daily did not result in improvement of pulmonary symptoms or function in the group as a whole, although one patient had small improvement in airflow. The baseline spirometric data and beta-agonist responsiveness of the patients in the study were then compared to a reference population consisting of 264 men who fulfilled a criteria for chronic obstruction out of 730 men who comprised a systematic sample drawn from all patients referred for spirometry at three hospitals. Our study subjects and those of five similar trials of corticosteroids in COPD had more severe obstruction than this reference group. Furthermore, the proportion of steroid responders found in each study was inversely related to the baseline FEV1 of the patients examined. It appears that previous studies of corticosteroids in COPD may have overestimated the number of COPD patients who might benefit from corticosteroids, due to a bias resulting from the selection of severely obstructed subjects.

Aged↗
PubMed1986

Analgesic effectiveness of D-phenylalanine in chronic pain patients.

Enkephalins are a biochemical pathway for endogenous analgesia. A number of compounds inhibit degradation of enkephalins within the body. One of these compounds, D-phenylalanine (DPA), has been shown to increase the pain threshold in animals. It is hypothesized that this naloxone reversible analgesia is induced by DPA blockage of enkephalin degradation by the enzyme carboxypeptidase A. Preliminary studies of chronic pain patients have shown a response rate to DPA from 32% to 75%. This study was a double-blind crossover evaluation of a randomized parallel design to determine the efficacy of DPA in 30 subjects with chronic pain from varied etiology which was unrelieved by multiple therapeutic interventions. Each patient received a stabilized therapeutic regimen during this study consisting of four weeks of either DPA 250 mg or lactose (placebo) orally four times a day. After four weeks the DPA and placebo groups were crossed over for an additional four weeks of treatment. Pain was quantified using a visual analog pain scale and a cold pressor test. Data from the pain questionnaires revealed more pain relief on DPA reported by 25% of the patients, more pain relief on placebo reported by 22% of the patients, and no difference in pain relief reported by 53% of the patients. Lowest pain level of the visual analog scale was reported by 47% of the patients on DPA and 53% on placebo. There appears to be no significant analgesic effect from D-phenylalanine in chronic pain patients when compared to placebo.

Animals↗
PubMed1986

Effects of atypical patterns of fetal growth on newborn (NBAS) behavior.

Newborn infants who showed anthropometric signs of atypical patterns of fetal growth were compared with infants of appropriate growth on the Neonatal Behavioral Assessment Scale (NBAS) and on recently developed supplementary items. The sample consisted of lower-socioeconomic-status families in San Juan, Puerto Rico, and included teenage and older mothers. Infants with atypical patterns of fetal growth showed lower scores than did infants of appropriate growth on the NBAS orientation, motor, and reflex clusters and on 15 of the 18 supplementary scores. Gestational age was covaried and showed independent effects on 6 items. Differential effects on measures of state and autonomic function were also found when the effects of the ponderal index were held constant. The results suggested that neonatal behavior is related to multiple indices of fetal growth patterns that may indicate early versus late nutritional insult. Supplementary NBAS items do not improve the discriminability of the NBAS but may help explain the basis for observed group differences.

Adolescent↗
PubMed1985

Broviac catheter sepsis: the natural history of an iatrogenic infection.

Between January 1982 and December 1983, 335 Broviac catheters placed in 270 infants and children were prospectively evaluated. The average duration of catheter life was 99.7 days, yielding a total accumulated experience of 33,394 catheter days. Blood culture-proven bacteremia occurred on 77 occasions (23%), an average of one spetic episode for every 434 days of catheter use. Temperature elevation was the only consistent clinical sign of infection occurring in 91% of the children. White blood cell counts remained within the normal range in the majority of patients. The differential counts were most helpful, however, documenting a significant increase in the number of immature neutrophils. The rise in band forms was frequently observed 24 to 48 hours before the onset of clinically evident sepsis. Platelet counts did not change significantly. Eighty-eight microorganisms were identified on blood culture. Eighty-three bacterial isolates were recovered (94%) and five fungi. The vast majority of patients (86%) had a single organism on blood culture but polymicrobial sepsis was observed on 11 occasions. Staphylococcus sp (38%) and Streptococcus sp (25%) species were most common. Of particular importance, 48% of coagulase negative staphylococci were nafcillin-resistant. Of the gram negative bacteria, Klebsiella (10%) and Pseudomonas (6%) species were most frequent. In 53 patients, antibiotic therapy was administered in an attempt to salvage the catheter. Bacteremia was controlled successfully in 39 (74%), and in the other 14 children, persistent sepsis dictated catheter removal. One patient (0.4%) died as a result of catheter-related sepsis.

Catheterization↗
PubMed1985

In vivo activation of mouse macrophages with beta-1,3-D-glucan-derivatized plastic beads.

Macrophages obtained from animals treated with beta-1,3-D-glucan-derivatized plastic beads were greatly stimulated, as judged by morphology, esterase release, and cytostatic effect on L-929 tumour cells in vitro. The pretreatment of mice with such beads conferred an apparent absolute local resistance to an otherwise lethal pneumococcal infection but had no effect on the growth of intraperitoneal AA ascites sarcoma. Moreover, peritoneal cells from animals pretreated with glucan beads did not protect the animals in a Winn assay.

Animals↗
PubMed1985

The rhythmic structure of mother-infant interaction in term and preterm infants.

The purpose of this study was to quantify social interaction rhythms in 3- and 5-month-old term and preterm infants and their mothers. Infant-mother dyads were videotaped in a 3-min face-to-face paradigm. For each second of the interaction, separate scores were assigned to infant and mother indicating levels of affective involvement, creating 2 180-sec time series. Spectral and cross-spectral techniques were used to quantify periodicities in each member of the dyad and to estimate the synchrony or coherence of interactional rhythms between each infant and mother. Results showed the existence of periodicities in the behavior of each infant and mother at 3 and 5 months, with most subjects showing spectral peaks between .022 and .10 Hz. Increases from 3 to 5 months in behavioral periodicities were found for infants and mothers as well as for the coherence between infant-mother dyads. Term dyads showed higher coherence than preterm dyads at both 3 and 5 months. Term infants more often led the interaction at both ages. These results were taken as evidence that behavioral periodicities, which may be biologically based, underlie early mother-infant interaction and provide a temporal structure for the organization of cognitive and affective experience. Differences in synchrony between term and preterm infants may explain later reported differences in language between these groups.

Age Factors↗