Mothers' representations of their relationships with their toddlers: links to adult attachment and observed mothering.

Mothers (N = 125) and their firstborn sons were studied over an 11-month period to examine relations between mothers' representations of their relationships with their children (measured at 15 months by using the Parent Development Interview [PDI]), adult representations of attachment (measured at 12 months by using the Adult Attachment Interview [AAI]), and observed mothering (measured at 15 and 21 months). Results indicate (a) that mothers classified as autonomous on the AAI scored highest on the joy-pleasure/coherence dimension of the PDI and mothers classified as dismissing on the AAI scored highest on the anger dimension of the PDI and (b) that mothers scoring higher on the joy-pleasure/coherence dimension of the PDI engaged in less negative and more positive mothering.

Earned security, daily stress, and parenting: a comparison of five alternative models.

Research suggests that adults who have developed a coherent perspective on their negative, early attachment relationships (i.e., earned secures) do not reenact poor parenting practices with their own children. However, no studies have addressed whether earned secures maintain positive parenting under the pressures of aversive environmental conditions. This study tested five alternative models that predict how earned secures parent under low and high stress in comparison to adults who had a positive upbringing (i.e., continuous secures) and adults who have an incoherent perspective on a troubled childhood (i.e., insecures). Only if earned secures exhibit effective caregiving under high stress, in comparison to the other security groups, can it be assumed that they have broken the intergenerational cycle of poor parenting. The Adult Attachment Interview was used to classify 97 mothers as earned secure, continuous secure, and insecure. Home observations of parenting and maternal self-reports of daily hassles (our stress measure) were obtained when children were 27 months old. Planned comparisons revealed that the diathesis-stress/incoherent present state of mind model most accurately predicted parenting. Thus, under high stress, the earned secures parented equivalently to the continuous secures and more positively than the insecures; under low stress no group differences were obtained. These findings indicate that in a normative sample earned secures break the intergenerational cycle and exhibit resilient parenting even under high stress conditions.

Risk factors for intracranial hemorrhage in the extracorporeal membrane oxygenation patient.

The need for cardiopulmonary resuscitation and repeated correction of persistent acidosis identifies extracorporeal membrane oxygenation patients more likely to develop an intracranial hemorrhage. The objective of this study was to identify risk factors for an intracranial hemorrhage (ICH) in infants on extracorporeal membrane oxygenation (ECMO). This study was a retrospective-matched, case-controlled study of infants with ICH on ECMO compared with infants without ICH on ECMO. Data collected included patient demographics, ventilator parameters, blood gases, coagulation parameters, the need for cardiopulmonary resuscitation (CPR), neurologic findings, and outcome. The Neonatal Intensive Care Nursery at Kosair Children's Hospital in Louisville, Ky., was the setting. Twenty-three infants who developed an ICH (excluding subarachnoid hemorrhage) on ECMO were matched with a control group of 23 infants without an ICH on ECMO. The presence of acidosis (pH < 7.19 or HCO3 < 17; p < 0.01 and p < 0.05, respectively) and the need for CPR (heart rate < or = 80 or mean blood pressure < or = 30 mm Hg, p < 0.003) shortly before or during cannulation correlated with the development of an ICH in infants on ECMO. The infants with an ICH required more frequent platelet transfusions (p < 0.005), had difficulty maintaining activated clotting times (ACTs) within a normal range (p < 0.03), and had abnormal neurologic examinations shortly before or after the ICH was detected with head ultrasound. The ultrasound was obtained as soon as possible after a change in the neurologic status. The need for CPR and repeated correction of persistent acidosis before or during cannulation identifies ECMO patients more likely to develop an ICH. We found that elevated ACTs and low platelet counts requiring transfusion showed a statistical association with the development of an ICH. Daily head ultrasounds and frequent neurologic checks are thus valuable tools in assessing the ECMO patient who demonstrates difficulty in maintaining coagulation values in the normal range or who requires frequent platelet transfusions.

Development and characterization of monoclonal antibodies specific for amylin.

Highly selective monoclonal antibodies to the peptide hormone human amylin have been produced and characterized. These antibodies are produced by hybridomas resulting from the fusions of BALB/c-derived myelomas and splenocytes from either inbred or outbred mouse strains. Certain of these antibodies recognize epitopes at the amino-terminus or the amidated carboxy-terminus, as well as conformational epitopes within the central region of the 37 amino acid peptide. Several of these antibodies show less than 0.1% cross-reactivity with related peptide hormones such as calcitonin and calcitonin gene-related peptide (CGRP) and have apparent affinities in the low nanomolar range. Antibody pairs were selected for use in two-site assays for the direct measurement of endogenous amylin and the synthetic human amylin analogue, pramlintide (25, 28, 29 tripro-human amylin), which is presently under clinical investigation for improving glucose control in patients with both Type I and Type II diabetes treated with insulin.

An anti-IL-2 antibody increases serum half-life and improves anti-tumor efficacy of human recombinant interleukin-2.

We examined the ability of anti-human recombinant interleukin-2 (hu rIL-2) monoclonal antibody DMS-1.10 to increase serum half-life of hu rIL-2, and the effect of this complex on inhibition of tumor progression in a B16-F10 murine melanoma model. In C57B1/6 mice, intravenous (i.v.) injection of DMS-1.10 premixed with 1 x 10(4) units (U) of hu rIL-2 at a 1:1 molar ratio extended serum half-life greater than 10-fold (222 min) when compared to the same dose of hu rIL-2 alone (20 min). In a murine tumor model, multiple intraperitoneal (i.p.) injections of non-neutralizing DMS-1.10 premixed with hu rIL-2 at a 5:1 molar ratio reduced the growth rate of subcutaneous (s.c.) B16-F10 tumor in C57B1/6 mice by 64% when compared to PBS and irrelevant antibody treated controls. Although similar treatment with hu rIL-2 alone reduced tumor growth rate by 46%, it was significantly less effective than the premixed treatment. Results from a flow cytometry assay confirm B16-F10 does not have IL-2 receptors, precluding direct inhibition of tumor growth by hu rIL-2 treatments. We propose that therapeutic efficacy of hu rIL-2 is improved by prolonging the in vivo half-life with an anti-IL-2 antibody, thus augmenting hu rIL-2 bioactivity and enhancing the hosts immune response against tumor.

The effects of tri-o-cresyl phosphate and metabolites on rat Sertoli cell function in primary culture.

A neurotoxic organophosphate, tri-o-cresyl phosphate (TOCP) is also a testicular toxicant. Histopathologic damage in the testis is first seen in Sertoli cells. TOCP and its activated metabolite saligenin cyclic-o-tolyl phosphate (SCOTP) were evaluated for effects on rat Sertoli cells in primary culture. SCOTP, but not TOCP, caused minor morphologic effects on the cells and increased levels of lactate in the spent medium with no change in pyruvate levels, synthesis of cellular or secreted proteins, or the cyclic AMP response to FSH stimulation. SCOTP was the metabolite of TOCP that produced the largest decrease in nonspecific esterase activity in Sertoli cells (up to 80%), when tested in the concentration range found in vivo. This decrease is consistent with previous in vivo evidence. These in vitro experiments replicate previously observed in vivo biochemical effects and suggest that SCOTP is the metabolite responsible for at least some of the biochemical effects seen in the testis after TOCP exposure.

Purification and characterization of a chimeric bifunctional antibody specific for human carcinoembryonic antigen and indium-benzyl-EDTA.

We describe the purification and characterization of a genetically engineered mouse/human chimeric bifunctional antibody specific for human carcinoembryonic antigen and indium-benzyl-EDTA. A clone expressing the bifunctional antibody has been previously described by our group and was found in this investigation also to express monospecific antibodies as well as Ig forms with mismatched light and heavy chains. The physicochemical properties of these various chimeric immunoglobulins were nearly identical. Isoelectric focusing showed that all these immunoglobulins have pI values between 8.47 and 8.80. A purification method that separates the bifunctional antibody from other Ig forms expressed in the same clone has been devised by relying on a unique interaction between the metal chelate binding region of these antibodies and the sulfopropyl functional group of a TSK SP 5-PW column.

Semen analysis and fertility assessment in rabbits: statistical power and design considerations for toxicology studies.

Semen analysis is commonly used in evaluating human response to reproductive toxicants. Serial semen samples can be collected from rabbits and fertility assessed by artificial insemination, hence this species is potentially well suited for male reproductive toxicity studies that might be extrapolated to humans. However, the size and cost of rabbits often restricts the number of animals used, reducing the sensitivity of such studies. Therefore, it was of interest to optimize study design for semen analysis and fertility assessment in rabbits. Semen samples were collected weekly from sexually mature New Zealand white rabbits and a range of parameters was analyzed (Semen--pH, volume, osmolality; Sperm--number and concentration, morphology, viability, percentage motility, motion characteristics; Seminal plasma--fructose, citric acid, carnitine and protein concentrations, acid phosphatase activity). Male fertility was assessed by inseminating female rabbits with the minimum number of motile sperm required for normal fertility, determined to be one million. The within- and between-buck variabilities were determined for all parameters and used to calculate the statistical power of different study designs. The variability of sperm number and concentration was decreased when measured in four ejaculates collected within a short period of time rather than in a single ejaculate; this was not true of other endpoints measured. In addition, use of preexposure observations further increased the statistical power for all of the parameters. These data can be used to determine the optimum design for studies of male reproductive toxicity using rabbits, with particular regard to cost and the number of animals used.

Expression and characterization of a chimeric bifunctional antibody with therapeutic applications.

A simple method is described for the generation of a biologically produced mouse/human chimeric hetero-bifunctional antibody that has dual specificity for human carcinoembryonic Ag and metal chelate haptens. Two large compound chimeric vectors each containing the genetic information to produce a single antibody specificity were sequentially electroporated into the murine nonsecreting hybridoma SP2/0. This led to the isolation of a clone expressing high levels of total IgG (up to 25 micrograms/ml/10(6) cells), 10 to 20% of which showed simultaneous reactivity with both Ag. Binding studies showed that the immunoreactivities and affinity constants for the individual arms of the bifunctional antibody were equivalent to those seen with the parental antibodies.

The interaction of Sertoli and Leydig cells in the testicular toxicity of tri-o-cresyl phosphate.

Previous studies have shown that after dosing with tri-o-cresyl phosphate (TOCP), the testis contains more active intermediate (saligenin cyclic-o-tolyl phosphate; SCOTP) than do other organs or blood. SCOTP is produced by a cytochrome P450-dependent reaction, and the Sertoli cells, although containing little P450, are the testicular cells that show the first signs of damage after TOCP administration. The present studies evaluated (i) whether testicular Leydig cell production of SCOTP might explain the elevated testicular concentration of SCOTP, (ii) if this production affected testosterone secretion, and (iii) if Sertoli cells cocultured over TOCP-exposed Leydig cells would show effects similar to those found after SCOTP exposure of Sertoli cells in vitro, indicating a cell interaction. Previous data showed that a target enzyme for SCOTP in Sertoli cells, nonspecific esterase (NSE), was inhibited by exposure in vitro to SCOTP, but not to TOCP. In the present experiments, HPLC analysis identified SCOTP in media from Leydig cells cultured with radiolabeled TOCP, demonstrating activation. TOCP addition to Leydig cells decreased testosterone output after stimulation with hCG, an effect that was replicated by subsequent in vivo experiments. Addition of various intermediates in the testosterone biosynthesis pathway indicated that both mitochondrial- and microsomal-based steps in the pathway were affected. Collectively, these data indicate that Leydig cells can activate TOCP. To model whether this activation might affect Sertoli cells in vivo, Sertoli cells were plated in culture-well inserts suspended above (cocultured with) isolated Leydig cells in the presence of TOCP. Sertoli NSE activity was diminished, while remaining unchanged when cultured in the presence of TOCP but without Leydig cells, or over Leydig cells alone. These results show that the Leydig cells in the testis are capable of activating TOCP to SCOTP, and that this can produce effects in Sertoli cells. This in situ activation of TOCP to SCOTP may help explain why the testis contains high concentrations of SCOTP after in vivo dosing with TOCP, and why the testis is a target organ for TOCP toxicity.

Toxicology studies of a chemical mixture of 25 groundwater contaminants. III. Male reproduction study in B6C3F1 mice.

A mixture of chemicals has been developed that models contaminated groundwater around hazardous waste sites. We investigated the effects of this mixture on spermatogenesis in B6C3F1 mice. The animals consumed three different concentrations of this mixture for 90 days, after which time they were euthanatized. Although there was a concentration-related decrease in the amount of fluid consumed at the higher two concentrations, there were no differences in body weight among the groups. Similarly, there was no effect of mixture consumption upon the histology of liver, kidney, testis, epididymis, or seminal vesicles or upon the absolute organ weights of these organs. Kidney weight relative to body weight was increased in the high dose group. Epididymal sperm number and testicular spermatid count were not affected by treatment. These studies show that, at exposure levels that decrease fluid intake and increase adjusted kidney weight, there were no effects of this mixture on gametogenesis in male mice.

Mono-2-ethylhexyl phthalate, a metabolite of di-(2-ethylhexyl) phthalate, causally linked to testicular atrophy in rats.

Acute testicular atrophy results when appropriate dosages of di-(2-ethylhexyl) phthalate (DEHP) or its hydrolysis product mono-2-ethylhexyl phthalate (MEHP) are given to male rats. Events thought to be involved in this pathological effect also occur in cultures of testicular cells in vitro, but require MEHP rather than DEHP. Primary cultures of hepatocytes, Sertoli cells, and Leydig cells were incubated with 14C-labeled MEHP [8 microM] for up to 24 hr. No significant reduction in viability was produced under these conditions. In contrast to the hepatocytes, which extensively metabolized MEHP to a variety of products in 1 hr, the testicular cell cultures were apparently unable to metabolize MEHP (beyond a slight hydrolysis to phthalic acid by Sertoli cells) in 18-24 hr. MEHP was efficiently taken up by hepatocytes, but much less so by testicular cells. These results, combined with related observations from the literature, support the hypothesis that MEHP itself is the metabolite of DEHP responsible for testicular atrophy in rats.

Decline in growth and antibody production of established hybridomas and transfectomas with addition of interleukin 6.

Several sources of the lymphokine interleukin (IL) 6 (human recombinant IL 6, supernatant from P388D1, a murine macrophage cell line and murine thymocyte-conditioned media) were examined for enhancement of growth, immunoglobulin (Ig) secretion and seeding density requirements in murine hybridoma and transfectoma cell lines established in the absence of exogenously added IL 6. None of these preparations increased growth or Ig secretion in the six cell lines studied. In fact, inhibition of proliferation was seen with two of the three IL 6 preparations. Human recombinant IL 6 showed no effect on minimal seeding density, but murine thymocyte-conditioned media gave a tenfold decrease in minimal seeding density requirements in one of two hybridomas and one of two transfectomas studied. All preparations contained active IL 6, as measured by proliferation of the IL 6-dependent cell line T1165.D10. These data show that IL 6 alone does not increase growth or Ig secretion for these established cell lines. This finding is compared with previous reports describing increased growth in primary cultures of murine hybridomas and human myelomas with IL 6.

The effects of mono-(2-ethylhexyl)-phthalate on rat Sertoli cell-enriched primary cultures.

There is considerable evidence from in vivo studies that the Sertoli cell is an initial target cell for the actions of phthalates in the rodent testis. Because this metabolically active cell type plays a central role in spermatogenesis, we examined the effects of a toxic phthalate, mono-(2-ethylhexyl)-phthalate (MEHP), on the secretory and synthetic activities of primary testicular cell cultures isolated from 18-day-old rats. These cultures were 78-84% Sertoli cells. Exposure to MEHP decreased cellular ATP by ca. 20%, decreased production of radiolabeled 14CO2 from acetate, and decreased media levels of pyruvate, while it increased media levels of lactate and intracellular lipid. Protein synthesis, evaluated by radiolabeled leucine incorporation, was not affected by MEHP. Mitochondrial succinate dehydrogenase activity was decreased in the presence of MEHP. Michaelis-Menton kinetic analysis indicated this was a mixed inhibition. There was no apparent change in mitochondrial Rhodamine 123 uptake. These data are consistent with the concept that mitochondria are one target for the actions of MEHP in the Sertoli cell.

Alkaline phosphatase histochemistry discriminates peritubular cells in primary rat testicular cell culture.

Histochemical demonstration of alkaline phosphatase activity appears to be useful in identifying rat peritubular cells in primary testicular cell culture. In both frozen sections of rat testis and Mirsky's fixed, methacrylate-embedded rat testis, the reaction product localized primarily in peritubular cells, vascular endothelium and occasionally in interstitial cells, with much smaller amounts of reaction product associated with elongating spermatids in the germinal epithelium. Occasional late-stage tubules (X-XIV) showed weak reactivity in the epithelium, associated with spermatocytes or Sertoli cells. Ultrastructurally, Gomori-method reaction product was localized to peritubular cells, lymphatics, and spermatogonia in stage VII; no staining was found consistently in Sertoli cells. In isolated cell preparations enriched for Sertoli and germ cells, 1 to 8% of the cells demonstrated alkaline phosphatase activity, while greater than 50% of the cells stained positive for alkaline phosphatase activity in peritubular-enriched fractions. The histochemical demonstration of alkaline phosphatase activity can be useful for identifying peritubular cells in primary cultures of testicular cells.

Microcomputer applications in allied health education: some new alternatives.

Allied health educators should consider that today low-cost microcomputer hardware and software that can significantly enhance the efficiency and effectiveness of teaching are available. These alternative educational applications of microcomputer technology in allied health can be developed by faculty themselves without programming or reliance on computing experts. Such applications include word-processing software for creation and revision of syllabi, exams, and handouts; data base management software for creation of large sets of bibliographic references, storage and retrieval of data on student admissions and matriculation, and management of clinical affiliations; spreadsheet software for preparation of budgets, calculation of student grades and test item analyses, and demonstration of physiologic and biologic phenomena; and graphics software for production of graphs and charts and printing of graphic images. These instructional support uses of microcomputers hold the greatest promise for near-term cost benefit in allied health education.

Into the looking glass: self-assessment for allied health faculty development.

Frequently allied health faculty are unprepared to assume the role of professional academician. Instituting a professional development program can assist faculty in enhancing their effectiveness in that role. As the first step, a faculty group in the School of Health Related Professions, State University of New York at Buffalo, designed a questionnaire to obtain information on faculty members' judgments about their own skills in various activities--teaching, research, writing, service, and administration--and the importance of these activities. The goal of this survey was to identify those activities for which there was the greatest need for faculty development. Research and writing were identified as areas having the greatest overall potential for professional development. The survey also provided groundwork for implementing an on-going professional development program that could be systematically evaluated.