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Biomedical subjects

M L Cooper

Publications and source records attributed to M L Cooper.

At least 73 records · Page 4Linked to original sources
PubMed1990

In vitro effects of matrix peptides on a cultured dermal-epidermal skin substitute.

Composite dermal-epidermal skin substitutes rely on a firm attachment of human keratinocytes (HK) to the dermal substrate for graft survival on the wound. An in vitro study was performed assessing whether the addition of matrix peptides to the dermal substrate effected the epithelial thickness. Cultured grafts were made by attaching HK to the external surface of a collagen-chondroitin 6-sulfate (GAG) membrane and inoculating human fibroblasts (HF) internally. If the matrix peptide (RGD Peptide) was added to the collagen-GAG membrane prior to placement of the HK and HF, the resultant epithelial layer at the end of the normal 4-day culture period was significantly thicker (19.7 +/- 0.9 microns versus 13.5 +/- 1.0 microns). Subjectively, the HF content was also greater on the peptide-treated grafts. When HF were not placed on the cultured graft, i.e., only collagen-GAG membrane, RGD peptide, and HK, the resultant epithelial thickness was even greater (28.3 +/- 1.0 microns). These data suggest that addition of matrix peptides, which increase cell attachment to the dermal substrate, may prove effective in the improvement of this cultured composite dermal-epidermal skin substitute.

Bandages↗
PubMed1990

Perceived social support, self-efficacy, and adjustment to abortion.

Prior to their having a 1st trimester abortion, women's perceptions of social support from their partner, family, and friends and self-efficacy for coping were assessed. Depression, mood, physical complaints, and anticipation of negative consequences were measured after the 30-min recovery period. As predicted, perceived social support enhanced adjustment indirectly through its effects on self-efficacy. Women who perceived high support from their family, friends, and partners had higher self-efficacy for coping. Higher self-efficacy, in turn, predicted better adjustment on the psychological measures but not on the physical complaint measure. No direct path between social support and adjustment was observed. In addition, women who told close others of their abortion but perceived them as less than completely supportive had poorer postabortion psychological adjustment than either women who did not tell or women who told and perceived complete support.

Abortion, Induced↗
PubMed1990

The influence of sociodemographic characteristics on familial alcohol problems: data from a community sample.

The moderating influence of race (black versus white), age, sex, and socioeconomic status on the relationship between alcohol abuse/dependence in offspring and a family history of alcoholism/problem drinking was investigated in a representative general population sample (N = 1659). Significant family history by race by age and family history by race by sex interactions were observed when predicting lifetime risk of alcohol abuse/dependence in offspring. Socioeconomic status did not moderate the effect of familial alcoholism/problem drinking on offspring alcohol abuse/dependence. Relative odds ratios indicated that the risk of alcohol abuse/dependence associated with a positive family history increased with increasing age among whites; whereas, it decreased with increasing age among blacks. Among whites, the relative odds ratio for the effect of family history was higher for females than for males; however, among blacks it was higher for males than females. Although these findings need to be replicated in other populations, they suggest that it is important to take race, age, and sex into consideration when investigating familial alcohol problems.

Adult↗
PubMed1990

Five-year reliability of self-reported alcohol consumption.

Reliability of alcohol consumption reported on a self-administered questionnaire was examined in 73 gynecologic outpatients. The questionnaire included quantity-frequency questions on current beverage-specific alcohol use (wine, beer and liquor). The questions were replicated 5 years later for both the earlier period and for current drinking patterns. Results indicated that, in general, original and retrospective data were highly correlated. Only recall of wine, the least frequently drunk beverage, was more highly correlated with current than with original consumption. Frequency of drinking was typically recalled better than quantity per occasion. Beverage-specific absolute alcohol per day (AA) was less reliable than total AA. Retrospective AA values accounted for 86% of the variability in original scores. The heaviest drinkers, however, tended to report disproportionately greater alcohol intake in retrospect. Thus, almost twice as many heavy drinkers were identified on the basis of their retrospective reports compared to those identified by their original reports. Results from this study suggest that considerable confidence can be placed in retrospective reports of total alcohol consumption by nonalcoholic women over a relatively long-term interval and that heavy drinking may be reported more accurately retrospectively than currently.

Adult↗
PubMed1990

Work stress and alcohol effects: a test of stress-induced drinking.

Drawing on both tension reduction and social learning theories, we hypothesized that work stressors lead to increased distress, which in turn promotes problematic alcohol use among vulnerable individuals. Vulnerable individuals are hypothesized to possess few personal and social resources for responding adaptively to work-related stressors and distress and to hold positive expectancies for alcohol's effects. We tested our model in a random sample of 574 employed adults, using a combination of path analytic and hierarchical moderated regression techniques. Results revealed no support for a simple tension reduction model of work stress-induced drinking and only limited support for a social learning model. We conclude that a much more circumscribed view of the etiologic role of work stress in problematic alcohol use is indicated.

Adolescent↗
PubMed1989

Burn wound closure with cultured autologous keratinocytes and fibroblasts attached to a collagen-glycosaminoglycan substrate.

Improved survival of patients with extensive burn injuries requires the development of better techniques for timely and permanent closure of the full-thickness wound. We developed procedures for establishing confluent, stratified layers of cultured, autologous keratinocytes on the surface of a modified collagen-glycosaminoglycan membrane that contains autologous fibroblasts. We transferred the composite grafts onto limited areas of excised full-thickness burn wounds of four patients with extensive burn injuries. Our results indicate that this composite graft material has acceptable "take," with formation of a basement membrane within 9 days of graft placement. Use of this technique for major wound coverage may offer a significant advance in the care of extensively burned patients and also may be useful for providing skin for reconstructive surgery.

Adult↗
PubMed1989

Roles of gender, gonadectomy and estrous phase in the analgesic effects of intracerebroventricular morphine in rats.

Gender and gonadal function have previously been shown to influence the magnitude of analgesia following systemic morphine and opioid and nonopioid forms of swim analgesia with male rats displaying greater analgesia than female rats and gonadectomy reducing analgesic magnitude in both genders. These effects have been presumed to be centrally mediated. The present study evaluated the roles of gender, gonadectomy and estrous phase upon dose-response and time-response functions of analgesia following intracerebroventricular administration of morphine as measured by the tail-flick and jump tests. Sham-operated male rats displayed significantly greater magnitudes of peak and total analgesia following central morphine than sham-operated female rats on both nociceptive measures. This striking effect was reflected both in terms of magnitude and ED50; while male rats displayed near-maximal analgesia at a 5 micrograms dose of morphine, female rats displayed moderate analgesia at doses as high as 40 micrograms of morphine. Castration produced small, but significant reductions in the magnitude of central morphine analgesia; the ED50 of morphine analgesia, however, was not changed. Although female rats in either proestrous or estrous displayed significantly greater magnitude of analgesia than ovariectomized rats or rats in a combined met-/di-estrous phase at some doses, the ED50 of morphine analgesia was not significantly altered as functions of estrous phase or ovariectomy. The interaction of opiate receptors and gonadal steroid receptors is considered as one possible determinant of gender differences observed in the magnitude and potency of central morphine analgesia.

Analgesia↗
PubMed1988

Loss of striatal mu1 opiate binding by substantia nigra lesions in the rat.

Opiate receptors have been identified within the striatum and some have been localized presynaptically to nigrostriatal neurons. Using unilateral ablative lesions of the substantia nigra, we examined binding in the ipsilateral and contralateral striata. Lesions significantly lowered both 3H[D-Ala2,MePhe4,Gly(ol)5]enkephalin (DAGO) and 3H[D-Ala2,Leu5]enkephalin (DADL) binding. The inclusion of competitors in these assays revealed a decrease in both mu1 and mu2 receptors. Mu1 binding was slightly more sensitive to the lesioning than mu2 binding. Selective mu1 and mu2 binding assays supported these observations. No change in delta binding was observed in the lesioned striata. These studies raise the possibility that both mu1 and mu2, but not delta, receptors are localized presynaptically on nigrostriatal neurons.

Animals↗
PubMed1988

Gender-specific and gonadectomy-specific effects upon swim analgesia: role of steroid replacement therapy.

Both gender-specific and gonadectomy-specific effects have been observed for the analgesic responses following continuous and intermittent cold-water swims (CCWS and ICWS respectively): female rats display significantly less analgesia than males, and gonadectomized rats display significantly less analgesia than sham-operated controls. The present study evaluated the effects of steroid replacement therapy with testosterone propionate (TP: 2 mg/kg, SC) upon CCWS and ICWS analgesia on the tail-flick and jump tests and hypothermia in sham-operated or gonadectomized male and female rats. Thirty days following surgery, rats received either no treatment, a sesame oil vehicle or TP for 14 days prior to, and then during testing. Relative to the no treatment condition, repeated vehicle injections in sham-operated rats eliminated the gender-specific, but did not affect the gonadectomy-specific effects upon CCWS and ICWS analgesia. TP reversed the deficits in CCWS and ICWS analgesia observed in both castrated and ovariectomized rats on both pain tests. TP only potentiated CCWS analgesia in sham-operated males on the tail-flick test. TP potentiated CCWS and ICWS hypothermia in gonadectomized rats and in male sham-operated rats. These data indicate that gonadal steroids play a major modulatory role in the etiology of swim analgesia, and that the observed gender effects are sensitive to possible adaptational variables.

Analgesia↗
PubMed1987

Modulation of gender-specific effects upon swim analgesia in gonadectomized rats.

Gender-specific effects have been observed for continuous and intermittent cold-water swim (CCWS and ICWS respectively) analgesia: analgesic magnitudes following CCWS and ICWS are significantly smaller in female rats than in age-matched and weight-matched male rats. The present study evaluated the role of gonadal status in these gender-specific effects by examining CCWS and ICWS analgesia, hypothermia and activity in intact and gonadectomized rats. Following confirmation of the original gender-specific effects on the tail-flick and jump tests, it was found that both castration and ovariectomy significantly reduced CCWS and ICWS analgesia. Indeed, castrated males displayed similar magnitudes of analgesia as intact females. The more marked hypothermia observed in intact females indicated that this variable failed to account for the analgesic gender-specific effects. The reduced hypothermia following gonadectomy also failed to account for the analgesic changes. The increased activity during ICWS, but not CCWS following gonadectomy also did not account for the analgesic changes. These data suggest that gonadal steroids normally appear to facilitate these stress-related analgesic responses.

Animals↗
PubMed1986

Accuracy of radiographic lung volume using new equations derived from computed tomography.

This study compared radiographic measurements of regional lung volume with corresponding physiologic measurements. The database included 48 normal, supine adults who had previously undergone spirometry and helium-dilution lung volume measurements to determine physiologic functional residual capacity (G-FRC) and total lung capacity (G-TLC). Chest x-rays had also been obtained for these subjects at functional residual capacity and total lung capacity. To calculate radiographic lung volumes at functional residual capacity and total lung capacity (R-FRC and R-TLC, respectively), we traced the lung outline from the chest x-ray, and digitized each outline. We then calculated total and regional lung volumes, using equations previously derived from computed tomographic scans. R-FRC and R-TLC were closely correlated (r = 0.973, maximum SEE 6.8%) with G-FRC and G-TLC, whether or not separate equations were used for regions below the diaphragm. Using only maximum anteroposterior diameter reduced the r-value to 0.957 (SEE 9.6%). The accuracy of our method of radiographic measurement of regional lung volume was validated by the concurrence between the physiologic and radiographic measurements.

Adult↗
PubMed1983

Gradients of cellular maturation and synaptogenesis in the superior colliculus of the fetal rhesus monkey.

Light (LM) and electron microscopic (EM) qualitative and quantitative analyses were employed to determine the tempo and spatial gradients of synaptogenesis and cellular differentiation in the superficial superior colliculus (SC) of the rhesus monkey between embryonic (E) days E47 and E84. By E47, a majority of the neurons of the prospective superficial gray layer (SGS) have arrived at their final positions and contribute to a uniform band of small, darkly Nissl-stained neurons at the outer surface of the SC. By E54, cells in the middle of the rostral pole of the superficial SC become considerably larger, paler staining, and less densely packed than the more medially or laterally located cells. These regional differences, which extend posteriorly through about the middle of the SC at this age, are evident on both the LM and EM levels and were confirmed by a quantitative EM analysis of the cytodifferentiation and synaptogenesis in the SGS. Several overlapping EM probes made across the medial, middle, and lateral regions of the SGS at each of three coronal levels reveal consistently more developed neuropil and smaller amounts of extracellular space in the middle region than in the medial and lateral portions of the more anterior SC. Further, the densities of synapses, both in terms of synapses/micron2 of total cross-sectional area and synapses/micron2 of neuropil alone, are also higher in the middle than the peripheral regions. Most of the middle-peripheral differences found in the mid-E50s are still evident by the early E60s, but have disappeared by midgestation (E80s). The present results are interpreted to indicate that the middle region of the SGS at a given transverse level begins to mature significantly earlier than the medial or lateral areas. Since our previous 3H-thymidine analysis (Cooper and Rakic, '81a) failed to reveal significant regional variation in the time of neuron origin in the superficial SC, the observed spatiotemporal gradients of neuronal maturation in the primate SGS probably do not arise from underlying gradients of cellular proliferation.

Animals↗
PubMed1983

Early divergence and changing proportions of neuronal and glial precursor cells in the primate cerebral ventricular zone.

Immunocytochemical staining with antisera directed against glial fibrillary acidic protein (GFA) was used to examine the cellular composition of the proliferative ventricular zone (VZ) in the occipital lobe of rhesus monkey fetuses during the first half of their 165-day gestational period. Electron microscopic analysis revealed a small number of GFA-positive cells in specimens of embryonic (E) ages E39 and E40. By E47 about 28% of the cells in the VZ were immunoreactive. This percentage increased to 37% at E61 and reached 60% by E80. The fraction of GFA-positive mitotic figures followed the same general tendency with 34, 47, and 80% being labeled at E47, E61, and E80, respectively. The present results reveal the existence of two basic classes of cells, GFA positive and GFA negative, indicating that in the primate brain, glial and neuronal precursor cells may coexist in the ventricular zone at embryonic ages when few, if any, neurons have become postmitotic.

Animals↗
PubMed1983

Retinohypothalamic pathway in the dove demonstrated by anterograde HRP.

The hypothalamic suprachiasmatic nucleus (SCN) of the ring dove was demonstrated by the presence of labeled retinal processes. Horseradish peroxidase or tritiated proline were injected into the vitreous of the eye and were transported in an anterograde manner to label the SCN. After identifying the retinorecipient area of the hypothalamus by anterograde tracing procedures, a diffusely organized nucleus corresponding to this region was noted in Nissl material.

Animals↗
PubMed1983

Effect of intravenous administration of T-2 toxin on blood coagulation in calves.

The single IV administration of T-2 toxin to calves at a dosage of 0.25 mg/kg of body weight produced statistically significant decreases in plasma activity of factors VII, IX, X, and XI and in fibrinogen values (P less than 0.05). Similar changes in the coagulation factors were observed after the single IV administration of T-2 toxin to calves which were given vitamin K (25 mg daily) for 5 days before and after dosing with T-2 toxin. The procoagulant activity of factor VIII was unaffected by T-2 toxin administration to calves.

Animals↗
PubMed1981

Neurogenetic gradients in the superior and inferior colliculi of the rhesus monkey.

The spatiotemporal patterns of neurogenesis in the superior colliculus (SC) and inferior colliculus (IC) were analyzed by plotting the positions of heavily labeled neurons in autoradiograms from a series of rhesus monkeys that had been exposed to 3H-thymidine at various embryonic (E) days and killed either shortly thereafter or at 2-3 months postnatally. Tectal neurons in this species are generated in the ventricular and subventricular zones surrounding the mesocoele (future Sylvian aqueduct) within the first third of the 165-day gestation period. Cells destined for the SC undergo final mitosis from E30 to E56, with peak proliferation from E38 to E43. These cells exhibit only a weak ventrodorsal gradient of neurogenesis and virtually no mediolateral or rostrocaudal gradients. Genesis of the neurons of the central nucleus (CN) of the IC also occurs between E30 and E56 and peaks around E43; but in contrast to cells of the SC, CN cells exhibit distinct rostrocaudal, lateromedial, and ventrodorsal gradients of genesis. Quantitative analysis revealed that whereas neurogenesis of the SC proceeds with about equal strength along the three cardinal axes, in the CN the lateral-medial gradient is significantly stronger than the anterior-posterior gradient. In addition, both the lateral-medial and ventral-dorsal IC gradients are significantly stronger than any SC gradients. Analysis of embryos sacrificed at short intervals following 3H-thymidine injection shows that the gradients are not caused by secondary lateral cell movement or by selective cell death. Thus, these findings suggest that within the generative zone of the midbrain tectum significant regional differences exist which result in distinctive spatiotemporal patterns of proliferation for the neurons of the primate superior and inferior colliculi.

Animals↗