Energy expenditure index of walking for normal children and for children with cerebral palsy

Energy expenditure indices (EEI) based on oxygen uptake and heart rate were used to compare the economy of walking at various speeds by normal and cerebral-palsied children. At low walking speeds, EEI values were high, indicating poor economy. At higher speeds the EEI values decreased until a range of maximum economy was reached. For normal children who were capable of walking beyond this range at higher speeds, the EEI increased again. This pattern was noted for both oxygen-uptake and heart-rate indices. Mean EEI values based on oxygen uptake and heart rate for normal children were significantly lower and occurred at faster walking speeds than values for children with cerebral palsy. EEI based on either oxygen uptake or heart rate can be used clinically to provide objective information to help evaluate the influence on gait function of surgical intervention, ambulatory aids or orthotics.

Prevalence of depression in family caregivers

Family caregivers who sought help to increase their coping skills (N = 158) and caregivers who volunteered for a longitudinal study of Alzheimer's disease (N = 58) were screened for depression. Among help-seekers, 46% had depression according to Research Diagnostic Criteria (RDC), but among non-help-seekers, only 18% met this criterion. In general, women were more depressed than men, but no major differences in the extent of depression were found in those who cared for more impaired persons.

Energy cost of walking in normal children and in those with cerebral palsy: comparison of heart rate and oxygen uptake

The rate of oxygen uptake can be used to assess energy expenditure during walking, but the necessary instrumentation is cumbersome, expensive, and usually unavailable in the clinical setting. Heart rate is an easily measured parameter, but its use as an index of energy expenditure in children has not been validated previously. We found that the relationship between oxygen uptake and heart rate was linear throughout a wide range of walking speeds for both children with cerebral palsy and normal children. There was no significant difference between the slope or the gamma-intercept of the lines for the two groups. These findings validate the use of heart rate as an index of energy expenditure for normal children and for children with cerebral palsy.

A new crystal form of ricin-OR

Ricin-OR, an antitumor toxin, has been crystallized in space group P2 with cell parameters a = 8.77 nm, b = 4.64 nm, c = 7.64 nm and beta = 101 degrees. There is one molecule in the asymmetric unit and the solvent content is estimated to be 48% by volume. The crystals diffract to 0.25 nm resolution which is higher than that of the previously reported C2 crystal form which had a solvent content of 65%.

Preliminary crystallographic analysis of glutamine-binding protein from Escherichia coli

Glutamine-binding protein from Escherichia coli, an essential component in the active transport of L-glutamine across the cytoplasmic membrane, has been crystallized by vapor diffusion in the presence of ammonium sulfate. The crystals exhibit pseudo-tetragonal symmetry with cell constants a = 77.5 A, b = 78.5 A and c = 90.2 A. Analysis of the diffraction data indicates that the space group is P2(1)2(1)2(1). There are two molecules per asymmetric unit and the solvent content is estimated to be 53%.

Neutrophilia and lymphopenia in major mood disorders

Alterations in peripheral blood leukocyte distribution in major depression, including lymphopenia, neutrophilia, eosinopenia, and monocytopenia, have been described. The present study was designed to replicate these results, but with methodological improvements, including age-, sex-, and race-matched control subjects; DSM-III and Research Diagnostic Criteria diagnoses based on the Schedule for Affective Disorders and Schizophrenia interview; objective and subjective severity of depression measured quantitatively; and consideration of psychosocial stressors (DSM-III, Axis IV). We found relative lymphopenia and absolute neutrophilia and leukocytosis in depression, but did not find decreased numbers of eosinophils or monocytes. The relative lymphopenia and absolute neutrophilia were present in the subgroup of only unipolar depressed patients, but not in the bipolar, currently depressed subgroup. However, these blood cell changes were not found in a subgroup of patients who had been medication free greater than or equal to 1 month but only in the subgroup of patients using medication at the time of phlebotomy. Groups formed on the basis of psychosocial stress levels were not found to have significant significant intergroup differences in white blood cell (WBC) counts. The clinical significance of these findings needs study. While leukocytosis and neutrophilia can be found in major depression, these changes are perhaps secondary to medication use.

Initial treatment of colic

This article discusses some of the rationales for the medical management of colic during the initial treatment period. The issue of colic pain control and the masking of clinical signs that may indicate severe gastrointestinal disease is addressed. Therapeutic considerations related to dehydration, metabolic imbalances, hemostatic disorders, antimicrobial therapy, fecal consistency, gastrointestinal decompression, and regulation of intestinal motility are reviewed.

Effect of naloxone on cigarette smoking

Several recent studies have tried to link endogenous opioid peptides (endorphins) with smoking reinforcement. Karras and Kane (1980) showed a one-third decrease in smoking after administration of the opiate antagonist naloxone. However, Nemeth-Coslett and Griffiths (1986) failed to replicate this result with use of a wide range of doses. The current study was an attempt to replicate Karras and Kane's results using 10 male chronic smokers. Each subject received naloxone (10 mg sc) or placebo in a double-blind, cross-over design (cross-over interval 6-14 days) after overnight abstinence from tobacco use. Naloxone reduced the number of cigarettes smoked by 16% in the first 1/2 hour smoking period, with a 10% reduction in carbon monoxide level 1 hour later. Naloxone had no effect on subjective and physiological variables and did not cause any signs of a tobacco withdrawal syndrome. These results are consistent with those of Karras and Kane, and suggest a role for endorphins in smoking reinforcement. Inconsistent results across studies may be due to methodological factors, such as differences in smoking deprivation time and postnaloxone administration testing intervals because naloxone has a short half-life.

Extraction and partial purification of a hepatic stimulatory substance in rats, mice, and dogs

A factor has been isolated from weanling rat liver which stimulates in vivo hepatic DNA synthesis in a dose dependent manner when injected into 40% hepatectomized rats. The factor has been partially purified by successive steps, involving ethanol precipitation, ultrafiltration through an Amicon PM 30 membrane, and finally fast protein liquid chromatography, resulting in a 38,000-fold increase in specific activity over that in the original cytosol. The factor contains a few bands in the molecular weight range of 14,000-50,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Active fractions from fast protein liquid chromatography (F150), when injected into 40% hepatectomized rats, increased hepatic DNA synthesis 3-fold over the background stimulation due to the hepatectomy. The response was dose dependent over a range from 1.76 micrograms to 6.8 micrograms per 200-g (body weight) rat. Mitotic and labeling indexes confirmed that F150 stimulates both replicative DNA synthesis and cell proliferation. The factor is heat and neuraminidase resistant, trypsin sensitive, organ specific, but not species specific.

Pulsatile release of gonadotropin-releasing hormone (GnRH) from the rat hypothalamus in vitro: calcium and glucose dependency and inhibition by superactive GnRH analogs

We have shown previously that the rat hypothalamus retains in vitro its capacity of generating pulsatile release of GnRH. The present study evaluated if pulsatile release of GnRH in vitro was influenced by metabolic conditions (calcium and glucose availability) and the possible self-regulatory role of GnRH in its pulsatile secretion. In the presence of a calcium-chelating agent (EGTA, 20 mM) or a calcium-channel blocker (D-600, 0.1 mM), the release of GnRH induced by a depolarization (veratridine, 50 microM) was markedly and reversibly decreased. In addition, frequency and amplitude of GnRH secretory pulses were significantly reduced (P less than 0.05). When glucose use was inhibited using 2-deoxyglucose (5.6 mM) the release of GnRH induced by veratridine and the frequency of GnRH pulses were also blunted (P less than 0.05). Superactive agonists of GnRH (Buserelin and D-TRP6-PRO9-N-ET, 10 nM) caused a prompt decrease of GnRH release in basal conditions and in the presence of veratridine. A significant inhibition (P less than 0.05) was observed using buserelin concentrations greater than 0.01 nM, whereas two GnRH analogs without biopotency (Leu8-GnRH, Des-gly10-N picolylamide GnRH, 100 nM) did not affect GnRH release. The two agonists of GnRH reduced by 43% to 66% (P less than 0.05) the occurrence of significant GnRH pulses. We conclude that, in vitro, the hypothalamic neuronal circuitry resulting in GnRH pulsatile secretion is dependent on calcium and glucose availability and is sensitive to an ultrashort-loop inhibitory feedback mechanism.

Apparent role of melatonin and prolactin in initiating winter fur growth in mink

A study was conducted to determine the effects of exogenous melatonin and bromocriptine (CB-154), an inhibitor of prolactin synthesis and secretion, on the induction of winter fur growth in mink. Melatonin (10 and 120 mg) was administered to mink (N = 5/group) via silastic implants inserted sc over the scapular area during the last week of June 1985. Treatment of mink (N = 5) with CB-154 alone or in combination with 10 mg melatonin (N = 5) consisted of daily sc injections of 2 mg of the drug in sterile saline from June 25 through July 30. Control animals (N = 5) did not receive injections of vehicle or sham implants. Administration of CB-154 alone or in combination with 10 mg melatonin, as well as 120 mg melatonin alone, initiated growth of the winter fur significantly earlier than that of controls or mink treated with 10 mg melatonin (P less than 0.05). These data suggest that inhibition of prolactin secretion by melatonin is requisite for induction of molt of summer fur and growth of winter fur of mink.

Significance of the "maturation" of metastases from Wilms' tumor after therapy

Several metastatic nodules were discovered in the lungs of a 4-year-old boy two years after surgical excision of Wilms' tumor with subsequent chemotherapy and local irradiation. All these metastatic nodules were composed of differentiated mesenchymal elements similar to those encountered in the primary neoplasm. Similar "mature" metastases have been observed by pathologists in other tumors of embryonic origin. Review of available literature and clinical and experimental data supports the notion that "reversion" of malignant cells into phenotypically benign counterparts may take place spontaneously or under the influence of environmental factors. Anticancer agents (cytostatics, radiation) selectively destroy the more anaplastic cells present in a malignant tumor (or its metastatic implants), thus allowing the "benign" revertants to predominate. Although such lesions are benign-appearing, it is recommended that they be completely excised; however, but further chemo- or radiotherapy may not be necessary.

Gallium scanning and tomography in the preoperative evaluation of lung cancer

Discrepant reports on the utility of gallium scanning in the preoperative evaluation of patients with lung cancer prompted a prospective study of the test. The authors studied 47 patients with lung cancer who underwent preoperative gallium scanning and frontal tomography of the mediastinum. Both tests were found to be most accurate in predicting the presence of mediastinal metastases among patients with squamous cell carcinoma. Both test may help direct surgical planning in patients with known squamous cell carcinoma of the lung.

Subungual malignant melanoma

An early accurate diagnosis of subungual melanoma depends upon an alert podiatric physician. Clinically, the lesion is often easily misdiagnosed and mistreated because of its resemblance to benign nail conditions. This paper discusses the incidence, histology, clinical findings, diagnosis, and treatment of this malignant lesion. An illustrative case report is presented.

Social support and adaptation to stress by the elderly

The first of a two-phase project is reported that examined the prospective effects of stress and social support on the physical and mental health of the elderly. A sample of 50 elderly subjects was assessed at two points in time over a 6-month period. Results indicated that social support was a significant predictor of physical health status, whereas mental health was related to the Stress X Social Support interaction term. These latter results were consistent with the buffering hypothesis, in that high levels of social support served to reduce the negative impact of stress on mental health. Individuals who were in better mental health at the initial assessment experienced fewer stressful events and higher levels of social support over the subsequent 6-month period. The implications of these findings for research and theory regarding the relation between stress and social support are discussed.

Changes in serum prolactin concentrations and ovarian prolactin receptors during embryonic diapause in mink

Experiments were conducted to determine if prolactin receptors were present in the mink ovary, and to examine the relationship between receptor numbers and serum levels of prolactin (PRL) during embryonic diapause and blastocyst reactivation. For analysis of the physicochemical properties of prolactin receptors, ovaries were obtained from anestrous mink. All binding determinations were made using 125I-ovine prolactin (125I-oPRL), and 20 micrograms of tissue protein from the 100,000 X g particulate fraction. To quantify prolactin receptors during gestation, 20 primiparous mink were mated twice on consecutive days between 4 and 10 March and assigned randomly to one of two groups. Mink in Group 1 (N=8) were killed on 13 March when blastocysts were completing their migration into the uterus and entering a state of diapause. Animals in Group 2 (N=10) were killed on 26 March during the period of blastocyst reactivation, just prior to implantation. To determine serum levels of prolactin during gestation, an additional 20 primiparous mink were similarly mated and bled every 4 days from 15 March to 8 April, and then every 7 days until 23 April. Prolactin concentrations were determined by a heterologous double antibody radioimmunoassay using porcine PRL for both tracer and standards. Optimum conditions for binding 125I-oPRL to ovarian membranes were attained at 25 degrees C after 12 h. Scatchard analysis revealed a single class of high affinity binding sites with a Kd of 6.14 X 10(-11) M. The total concentration of receptors during anestrus was 85 fmol/mg protein, which increased significantly during embryonic diapause to 484 fmol/mg protein, then declined to 16 fmol/mg during blastocyst reactivation.