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The structure of phycobiliproteins of the cyanobacterium Acaryochloris marina was investigated in buffer solution at physiological temperatures, i.e. under the same conditions applied in spectroscopic experiments, using small angle neutron scattering. The scattering data of intact phycobiliproteins in buffer solution containing phosphate can be well described using a cylindrical shape with a length of about 225Å and a diameter of approximately 100Å. This finding is qualitatively consistent with earlier electron microscopy studies reporting a rod-like shape of the phycobiliproteins with a length of about 250 (M. Chen et al., FEBS Letters 583, 2009, 2535) or 300Å (J. Marquart et al., FEBS Letters 410, 1997, 428). In contrast, phycobiliproteins dissolved in buffer lacking phosphate revealed a splitting of the rods into cylindrical subunits with a height of 28Å only, but also a pronounced sample aggregation. Complementary small angle neutron and X-ray scattering experiments on phycocyanin suggest that the cylindrical subunits may represent either trimeric phycocyanin or trimeric allophycocyanin. Our findings are in agreement with the assumption that a phycobiliprotein rod with a total height of about 225Å can accommodate seven trimeric phycocyanin subunits and one trimeric allophycocyanin subunit, each of which having a height of about 28Å. The structural information obtained by small angle neutron and X-ray scattering can be used to interpret variations in the low-energy region of the 4.5K absorption spectra of phycobiliproteins dissolved in buffer solutions containing and lacking phosphate, respectively., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Juvenile male rhesus macaques received therapeutic doses of fluoxetine daily from one to three years of age and were compared to vehicle-treated controls (N=16/group). Genotyping for monoamine oxidase A (MAOA) polymorphisms was used to form subgroups (N=8) with high and low expression of the gene. Behavioral responses were scored during 30-second exposures to pictures differing in affective content. As expected from its therapeutic effect, fluoxetine decreased the behavioral response to emotionally evocative pictures. A 44% reduction in number of expressive behaviors was seen, but only in subjects with low expression MAOA polymorphisms. In general, this effect occurred for pictures of varying affective content and was not due to altered occurrence of one specific behavior or type of behavior. The drug*genotype interaction was seen after one and two years of treatment and did not reverse one year after discontinuation of dosing. Two potential translational implications are suggested: (1) MAOA genetic polymorphisms may be the source of some of the variability in response to fluoxetine treatment in children; (2) extended fluoxetine treatment during juvenile brain development may result in persistent effects on emotional regulation., (Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.)

Iron deficiency has been shown to impair dopamine functioning in rodent models, but it is challenging to obtain evidence of such effects in human infants. Because spontaneous eye-blink rate may provide a noninvasive assessment of dopamine functioning, we hypothesized that eye-blink rate would be lower in infants with iron-deficiency anemia and would increase with iron therapy. A 4-min eye-blink assessment was conducted for quiet, alert infants sitting on their mother's lap. Data were available for 61 9- to 10-mo-old infants from inner-city Detroit (19 iron-deficient anemic, 23 nonanemic iron-deficient, and 19 nonanemic iron-sufficient). Iron-deficient and iron-sufficient nonanemic groups had similar eye-blink rates (P = 0.90) and were therefore combined. We used Poisson regression based on generalized estimation equation methodology to test for differences between iron-deficient anemic and nonanemic infants in blinks/min and change after 3 mo of iron therapy. Iron-deficient anemic infants had a lower initial eye-blink rate than nonanemic infants (mean +/- SD) (4.0 +/- 1.9 vs. 5.3 +/- 2.8 blinks/min; P = 0.02; effect size = 0.6 SD). At 12 mo, eye-blink rate increased by 2.1 blinks/min in the iron-deficient anemic group (P = 0.008); there was no change in the nonanemic group (P = 0.96). These results are consistent with reduced dopamine function in iron-deficient anemic infants. The clinical importance of a lower eye-blink rate is unclear, but impaired dopamine functioning is likely to have broader impact, given the role dopamine plays in regulating movement, motivation, cognition, and hormone release.

Marginal iron (Fe) deficiency is prevalent in children worldwide, yet the behavioral and biochemical effects of chronic marginal Fe intakes during early development are not well characterized. Using a murine model, previous work in our laboratory demonstrated persistent behavioral disturbances as a consequence of marginal Fe intakes during early development. In the present study, Swiss-Webster mice fed a control Fe diet (75 microgram Fe/g diet, n = 13 litters) or marginal Fe diet (14 microgram Fe/g diet, n = 16 litters) during gestation and through postnatal day (PND) 75 were killed on PND 75 for assessment of tissue mineral concentrations, dopamine metabolism, myelin fatty acid composition, and c- and m-aconitase activities. In addition, these outcomes were assessed in a group of offspring (n = 13 litters) fed a marginal Fe diet during gestation and lactation and then fed a control diet from PND 21-75. Marginal Fe mice demonstrated significant differences in brain iron concentrations, dopamine metabolism and myelin fatty acid composition relative to control mice; however, no difference in c- or m-aconitase activity was demonstrated in the brain. The postnatal consumption of Fe-adequate diets among marginal Fe offspring did not fully reverse all of the observed biochemical disturbances. This study demonstrates that chronic marginal Fe intakes during early development can result in significant changes in brain biochemistry. The persistence of some of these biochemical changes after postnatal Fe supplementation suggests that they are an irreversible consequence of developmental Fe restriction.

In three experiments, high aluminum diets (1000 microg Al/g diet) were fed to mice throughout their life span to determine whether neurodegenerative changes were seen with aging. Brain Al concentrations were slightly lower in Al-treated mice than controls. Generally, no increased mortality or gross evidence of neurodegeneration was seen in Al-treated mice. Eighteen and 24 month old Swiss Webster mice fed the high aluminum diet differed from controls on some neurobehavioral tests, but differences were no greater than previously seen with shorter term exposure in younger mice. Both brain Al concentration and susceptibility to oxidative damage, as measured with TBARS, were lower in the Al-treated aged mice than in controls. In addition, Al-treated aged Swiss Webster and C57BL/6J mice showed somewhat enhanced performance in the Morris water maze. Finally, Al treatment did not exacerbate the effect of MPTP treatment on a grip strength measure in either 66 or 235 day old male mice. Swiss Webster and C57BL/6J mice do not appear to provide useful models for studying Al-induced neurodegenerative changes in aging.

The objective of this study was to investigate the behavioral and cognitive outcomes associated with chronic marginal iron (Fe) intakes during early development. Offspring (3 males and 3 females/litter) of Swiss-Webster female mice who had been fed a control Fe diet (75 microg Fe/g diet) or marginal Fe diet (14 microg Fe/g diet) for 9 wk before mating were weaned on postnatal (PND) 21. Offspring of marginal Fe dams were fed either the marginal Fe diet (marginal group) or a control diet (replete group) from PND 21 throughout the duration of the study, whereas offspring of control dams consumed the control diet ad libitum (control group). On PND 30, 45 and 60, one male and female per litter underwent grip strength and auditory startle testing. A Morris maze was used to assess cognitive function in males starting at PND 50. Marginal Fe mice consistently demonstrated significantly lower grip strength, which was independent of differences in body weight. In addition, marginal Fe males demonstrated attenuated startle responsiveness, as well as altered performance in the Morris water maze. These differences in performance were found in association with lower brain Fe concentrations. Postnatal Fe supplementation did not reverse all of these disturbances because differences in brain Fe concentrations and maze learning persisted. This study demonstrates that chronic marginal Fe intakes during early development can result in persistent biochemical and behavioral changes in mice.

Primate species demonstrate a prolonged period of development before reproductive maturity that includes distinctive periods of rapid growth in the late fetal, late infancy and early adolescent stages. Rhesus monkeys resemble humans in this discontinuous pattern of growth and also in its relationship to brain development. Studies of zinc deprivation in rhesus monkeys have suggested an important relationship among growth rate, nutrient status and behavioral performance in infancy as well as adolescence. Recently, moderate combined zinc and iron deprivation (intake 0.2 mg Zn and 0.8 mg Fe/d, compared with control intake of 2.9 mg Zn and 1.7 mg Fe/d) during the adolescent growth spurt (29-32 mo. of age) of female rhesus monkeys (n = 8/group) was shown to influence behavior without affecting growth. Behavioral assessments included the Continuous Performance Test, the Delayed Nonmatch to Sample Test and activity (measured with an actimeter). The behavioral syndrome was characterized by reduced activity, reduced participation in behavioral testing and slower response. These changes could be reversed or prevented to some extent by altering the diet to include tablets of powdered beef (adding approximately 1.7 mg Zn and 0.7 mg Fe to daily intake). The study suggests that behavior may be sensitive to the quality of the diet available during the period of rapid adolescent growth and development.

Background: The adolescent growth spurt and menarche increase iron and zinc needs and could precipitate functional deficiencies if dietary sources are inadequate., Objective: The effects of mild, combined zinc and iron deprivation during the growth spurt and the ability of meat as a common dietary source of zinc and iron to reverse these effects was studied., Design: Pubertal female rhesus monkeys were fed control diets (n = 8) or diets marginally deficient in zinc (2 microg/g diet; n = 8) and iron (10 microg/g diet; n = 8) for 3 mo. A powdered beef supplement (104 microg Zn/g and 43 microg Fe/g, 11 +/- 2 g/d) was then fed daily to half of the deprived group for 3 additional months., Results: Growth and hematology were not affected significantly by iron-zinc deprivation, but plasma zinc and iron were somewhat lower in the deprived group than in the control group after 3 mo. The deprived monkeys reduced their participation in behavioral testing, responded more slowly and less frequently to test stimuli, and were less active. The beef supplement increased participation in testing and stabilized activity levels, but response times remained depressed. Plasma ferritin was lower in the nonsupplemented deprived monkeys than in the controls by the end of the experiment. Four of 8 of the deprived monkeys had iron deficiency anemia compared with none of the controls and 1 of 8 who received the beef supplement., Conclusions: Marginal zinc and iron deprivation in early adolescence can lead to behavioral and hematologic dysfunction in nonhuman primates and dietary beef supplements can prevent and reverse some of these effects.

The capacity of Al3+ to promote oxidative damage to brain membranes was investigated both in vitro and in vivo. In vitro, Al3+ and related metals (Sc3+, Ga3+, In3+, Be2+, Y3+, and La3+) stimulated Fe2+-initiated lipid and protein oxidation in brain myelin and synaptic membranes. Al3+, Sc3+, Y3+, and La3+ significantly promoted protein-associated carbonyl production in myelin, while in synaptic membranes, the stimulatory effect was observed in the presence of Ga3+, In3+, Y3+, Sc3+, and La3+. In myelin the magnitude of the stimulation of lipid oxidation followed the order Sc3+, Y3+, La3+ > Al3+, Ga3+, In3+ > Be2+. When compared to mitochondria and microsomal and synaptic membranes, myelin showed a marked susceptibility to Al3+-mediated lipid peroxidation. The differential susceptibility of myelin compared to synaptic membranes could not be explained by differences in membrane composition, since the relative content of negatively charged phospholipids (binding sites) was similar for both membranes, and myelin had a lower content of poly-unsaturated fatty acids (substrates of lipid oxidation) and a higher concentration of alpha-tocopherol compared to synaptic membranes. In a model of Al3+ intoxication imposed to mice during pregnancy and early development, a 72% higher content of lipid peroxidation products was found in brain myelin. The fluidity of myelin evaluated by the polarization fluorescence of 1,3-diphenylhexatriene was significantly higher in the Al3+-intoxicated mice than in controls. Since myelin has a high relative content of lipid:protein compared to other membranes, these results support our hypothesis that ions without redox capacity can stimulate in vitro and in vivo lipid oxidation by promoting phase separation and membrane rigidification, thus accelerating lipid oxidation.

Plasma protein concentrations are an important determinant of maternal-fetal drug transfer in the perinatal period. Plasma concentrations of alpha 1-acid glycoprotein (AAGP) and albumin were measured in pregnant rhesus monkeys using radial immunodiffusion assays at weekly intervals during the third trimester (n = 12), at 3-day intervals in the 2 weeks prior to full term (n = 10), and at 0, 1, 12, and 60 h after birth (n = 4). AAGP concentrations increased significantly, and albumin concentrations decreased significantly, from weeks 13 to 21 gestation as well as from day 150 gestation to birth. No changes were seen in the postpartum period. AAGP and albumin concentrations were highly negatively correlated from day 150 gestation to birth. The data suggest that AAGP and albumin concentrations are jointly but inversely regulated by physiological or hormonal conditions that precede delivery.

A large percentage of newborns are exposed to pharmacological agents that affect the brain in connection with pain management during labor. The two most commonly used agents are meperidine, administered intravenously or intramuscularly, and bupivacaine, administered by the epidural route. Over the years, infant behavioral assessments have been used in the neonatal nursery to identify labor analgesia regimens with minimal impact on neonatal status. However, considerable controversy has centered on the general issue of possible harm to the neonate from use of analgesia and anesthesia in obstetrics. Due to limitations on experiments in the obstetric situation and a lack of suitable animal models, the broader issues concerning the effects of these agents on the developing brain and possible long-term consequences for infant adaptive functioning have received little attention. A series of studies has recently been completed using a rhesus monkey model for administration of labor analgesia under controlled experimental conditions and long-term behavioral evaluation of infants. Most of the assessments, including those of cognitive function, were not influenced by perinatal analgesia. However, these studies have confirmed the neonatal depressant effects of meperidine and have suggested that the course of behavioral maturation during certain periods of infancy is influenced by both meperidine and bupivacaine administration at birth. These effects could occur as a result of effects on vulnerable brain processes during a sensitive period, interference with programming of brain development by endogenous agents, or alteration in early experiences.

Lethargy is characteristic of malnourished populations, but little is known about the biologic mechanism or consequences for cognitive performance. In the current experiment, 24-h activity patterns and performance of an attention task were studied in adolescent female monkeys (18-33 mo of age, n = 10/group) under conditions of moderate dietary zinc deprivation (2 micrograms Zn/g diet) and adequate dietary zinc (50 micrograms Zn/g). There were progressive decreases in daytime activity levels in the zinc-deprived group followed by slowing of growth around the time of the growth spurt. Attention performance was also impaired before the onset of growth retardation. Zinc-deprived monkeys failed to show the shift to later initiation of the rest phase of the diurnal cycle seen in controls in late adolescence. These data support previous findings that activity and attention can be affected during early stages of zinc deprivation before the onset of growth retardation.

Growth retardation has been associated with zinc deficiency in adolescent human populations, but animal models were not available previously to explore this syndrome. Moderate dietary zinc deprivation (2 micrograms Zn/g diet) was introduced in female rhesus monkeys (Macaca mulatta; n = 10) from the beginning of puberty through menarche. Subgroups of animals (n = 4) continued to be fed the zinc-deficient diet through 45 mo of age (sexual maturity). Reduced weight gain and linear growth and lower plasma zinc concentrations (11.8 +/- 0.6 and 9.2 +/- 0.8 mumol/L in control and zinc-deficient monkeys, respectively) were evident during the premenarcheal growth spurt. Slower skeletal growth, maturation, and mineralization were recorded in the postmenarcheal period and some indicators of sexual maturation were delayed. Food intake was slightly higher in the zinc-deficient group than in controls. These data confirm that adolescent growth and maturation are vulnerable to disruption by moderate dietary zinc deprivation in nonhuman primates.

High dietary A1 can result in lowered tissue Mn and Fe concentrations in weanling mice. Possible mechanisms underlying this effect of A1 (altered milk Fe and Mn content, altered absorption or retention of Fe and Mn) were investigated in this experiment. To determine if milk composition was changed, milk was analyzed for Fe and Mn at 0, 3, 7, and 12 days postnatal. To determine if A1 influenced absorption and/or retention of Fe and Mn, a single milk meal containing 54Mn and 59Fe was administered by gavage to 12 day old pups and tissues were obtained 6 and 24 h later. Pup body and tissue weights were not affected by the high A1 diet. Milk from dams fed high A1 diets (1000 micrograms A1/g, n = 11, A11000) had similar Fe and Mn concentrations as milk from dams fed a control diet (7 micrograms A1/g, n = 11), although A1 concentrations were higher. Absorption and tissue distribution of 54Mn and 59Fe, as determined at the 6 h timepoint, were unaffected by maternal diet group (control n = 16, AL1000 n = 10). However, total retention of both 54Mn and 59Fe was 8-10% lower in the AL1000 pups 24 h after gavage (P = 0.030 for Mn and 0.017 for Fe). These data suggest that high dietary A1 during development alters the ability of nursing mouse pups to retain absorbed Fe and Mn.

The majority of studies of developmental zinc deficiency and behavior were conducted in laboratory animals, primarily rats and rhesus monkeys. Effects on food intake complicate interpretation of experiments using severe zinc deficiency. Severe zinc deficiency in rats during the period of rapid brain growth has similar effects to protein calorie malnourishment during this period, including altered emotionality and food motivation. When behavior is tested during a period of zinc deprivation in immature animals, lethargy (reduced activity and responsiveness) is a prominent characteristic, but learning, attention and memory are also affected. The few supplement studies available in children did not report effects on behavior. Although zinc has multiple roles in brain function, considerable brain sparing occurs in zinc deficiency, and peripheral mechanisms of altered behavior also need to be considered.

Assessment of zinc nutriture is often compromised by the lack of reliable biomarkers. In the present study the effect of dietary zinc deprivation on plasma extracellular superoxide dismutase (EC SOD) activity was investigated in rat and rhesus macaque models. This enzyme, which contains both zinc and copper, is distinct from cytosolic copper-zinc SOD. Young, growing rats fed zinc-deficient diets (1.5 nmol Zn/g diet) were characterized by low plasma zinc concentrations and plasma EC SOD activities (16% and 56% of controls, respectively). Adolescent rhesus macaques fed diets that contained a marginal amount of zinc (30.6nmol Zn/g diet) also had low plasma zinc concentrations and low EC SOD activities compared with controls fed diets containing 765 nmol Zn/g diet (75% and 40%, respectively). Enzyme activity was not affected after in vitro addition of zinc to plasma samples from control, restrict-fed, and zinc-deficient rats. Taken together, these data support the concept that plasma EC SOD activity can be a biomarker for zinc status.

Young rhesus monkeys (Macaca mulatta, n = 14) 25-30 mo of age were fed a zinc-deficient (ZD) diet (2 micrograms Zn/g diet) (moderate zinc deprivation) over 15 week. The ZD diet period was compared with a zinc-adequate (ZA) diet period (50 micrograms Zn/g diet) of the same duration, which either preceded or followed it (crossover design). Plasma zinc was lower at the end of the ZD than after the ZA period. There were no overt signs of zinc deficiency or effects on growth rate. Spontaneous motor activity was lower and performance of a visual-attention task and short-term-memory task were poorer during the ZD period than during the ZA period. Behavioral effects were detected as changes from individual baseline values, and often represented a failure to improve. The results suggests that dietary zinc deprivation can modulate behavior in prepubertal monkeys without affecting growth.

Previous studies have shown that excess dietary Al during development can affect neurobehavioral measures and decrease tissue Mn of 21-day-old weanling mice without a corresponding increase in tissue Al concentrations. Al and Mn have similar tissue concentrations and similar affinities for transferrin, which is the major plasma transport protein for Al and Mn as well as Fe. In the present study, brain Al, Mn and Fe were studied at 6, 12, 18 and 24 days of age in offspring of Swiss Webster mice fed a semipurified diet containing excess Al (Al[+], 1000 micrograms Al/g diet, Al as Al lactate), marginal Mn (Mn[-], 3 micrograms Mn/g diet) or both excess Al and marginal Mn (Al[+]Mn[-]) from conception to day 24 postnatal (weaning on day 18). Brain Al concentrations were higher at 6 days of age than at later ages and were significantly elevated by the excess Al diet (P = 0.017) but returned to control levels by weaning. Brain Mn concentrations increased from day 6 to day 24 and were lower in the Mn deficient groups (P < 0.001) and also in the excess Al group (P = 0.024) than in controls. Brain Fe concentrations were not influenced by diet. Similar patterns were seen in liver as in brain. The marginal Mn diet led to postnatal growth retardation which was more severe in litters of dams fed Al[+]Mn[-] diets than in litters fed Mn[-] diet. These data suggest that excess Al in diet can interact specifically with Mn metabolism during development.

Fetal body movements were studied in three groups of gravid rhesus macaques fed different amounts of dietary zinc (100 micrograms Zn/g diet, control, n = 12; 4 micrograms Zn/g diet, marginal deprivation, n = 7; 2 micrograms Zn/g diet, moderate deprivation, n = 11). Sonographic examinations were conducted during the third trimester in awake chair-restrained dams. Movement categories, derived from the human biophysical profile, were motor activity (trunk and limb movements), startle, and breathing movements. Moderately deprived fetuses were more active than controls on gestational day (GD) 115; maternal plasma zinc concentrations were significantly correlated with fetal activity at this time. In addition moderately deprived fetuses exhibited fewer breathing episodes on GDs 115-135. Biometrics measures indicated growth retardation in one moderately deprived fetus. These data suggest that moderate, but not marginal, dietary zinc deprivation influences fetal status as evaluated by sonography.

Excessive dietary aluminum (Al) has been proposed to be a factor contributing to several neurological disorders in humans. Six 8-week-old female Swiss Webster mice were fed for 10 weeks purified diets containing 100 (control, 100 Al), 500 (500 Al) or 1000 (1000 Al) micrograms Al/g diet. Brain and liver lipid peroxidation was determined by evaluating the production of 2-thiobarbituric acid reactive substances (TBARS) in brain and liver homogenates in the presence or absence of 50 microM ferrous iron. TBARS production in the absence of iron in brain homogenates from mice fed the 1000 Al diet was higher (30%) than that in the 100 Al control group (3.1 vs. 2.4 nmol TBARS/mg protein). The addition of ferrous iron increased TBARS production in brain homogenates from all 3 dietary groups. The iron-induced TBARS production was 26% higher in the 1000 Al brain homogenates than in the 100 Al group (4.9 vs. 3.9 nmol TBARS/mg protein). Brain TBARS production in the presence and absence of iron was similar between the 100 and 500 Al groups. TBARS production in liver homogenates measured either with or without iron was similar for the 3 groups. These results show that, in mice, dietary Al intoxication leads to increased brain TBARS production, suggesting that enhanced lipid peroxidation may be one possible mechanism underlying the neurological damage associated with increased tissue Al.

Two studies of the responses to clonidine as the sole antihypertensive drug in the treatment of mild-to-moderate hypertension are reported. In the first, 11 patients with mild hypertension were treated with 0.1 mg clonidine twice daily for eight weeks. Those patients with "low renin" hypertension (n = 7) were noted to show an increase in plasma renin activity; the patients with "normal renin" hypertension (n = 4) tended to show a decrease. Both groups had a similar decrease in blood pressure. The changes in renin activity correlated significantly (p less than 0.01) with the small changes in endogenous creatinine clearance (r = 0.84). In the second study, 16 patients with mild-to-moderate essential hypertension were treated for three months with 0.2 mg clonidine three times daily. Blood pressure decreased from 167 +/- 4/105 +/- 2 to 140 +/- 3/90 +/- 2 mm Hg (p less than 0.01). Blood pressure changes correlated with decreases in plasma catecholamines (r = 0.61, p less than 0.001) and heart rate (r = 0.78, p less than 0.001). No significant changes in cardiac output, blood volume, renal blood flow, or glomerular filtration rate were noted. Clonidine is an effective and safe therapy when used as the sole medication in treating mild-to-moderate hypertension.

The immune system is gaining increasing attention as a target of toxicant action. Many compounds, including metals, drugs, and pesticides, are able to alter immune functions. Additionally, the ability of toxicants to experimentally alter resistance to a variety of bacterial, viral, and tumor challenges is suggestive for the possible involvement of toxicants in morbidity and mortality. However, the implications of immunotoxicology as a subject of study may not be fully realized in some laboratories due to unfamiliarities into the workings of immunity by toxicologists. In an attempt to bridge this toxicology-immunology gap, this paper presents the major concepts of the immune system by reviewing specific examples of immune responses and their environmental interactions. Data from selected toxins are then used to illustrate how these responses may be altered.

One of the possible mechanisms that has been proposed to underlie the deleterious effects of excess aluminum on brain function is an impairment in the normal formation of the cytoskeletal network. Based on recent reports that aluminum can promote the in-vitro polymerization of purified tubulin, in the present study we characterized the effects of high dietary aluminum on in-vitro microtubule formation in brain supernatants. Mice were fed diets containing aluminum 25-1000 micrograms/g for up to 10 weeks. Tubulin polymerization in high-speed brain supernatants was not found to be affected by dietary aluminum. However, we observed that the addition of aluminum in vitro stimulated microtubule assembly in brain supernatants from mice fed control diets, as had been previously reported. Thus, impaired brain microtubule function is not an early general biochemical lesion in aluminum toxicosis.

Growth was evaluated in rhesus monkey infants that were the offspring of females given a marginally zinc-deficient diet (4 micrograms/g zinc) from the beginning of pregnancy and through 12 months of postnatal life. These zinc-deficient (ZD) infants were compared to controls whose mothers were fed a complete diet, either ad libitum or pair-fed to zinc-deficient dams, throughout gestation and lactation. Male ZD infants had evidence of growth retardation at birth. In contrast, growth retardation in female ZD infants was not observed until 1 month of age. From 3 to 9 months of age (late lactation and subsequent to weaning) ZD infants attained weights similar to those of the control group. However, analysis of crown-rump and femur length indicated that ZD infants' growth was less than optimal throughout the entire 1st yr of observation. In addition, skinfold thickness was markedly higher in ZD than in control infants in the postweaning period. In the juvenile period (9-12 months of age) both male and female ZD animals fell behind controls in body weight. ZD juveniles were also hypogeusic, as determined by a quinine acceptance test. Low weight ZD infants had reduced somatic growth as reflected in sitting height, long bone growth, head circumference, and limb circumference. Regression analysis indicated that impaired growth rates from 9 to 12 months were associated with both lower food intake and reduced food use efficiency. Plasma zinc concentration was, in general, inversely related to weight gain in both groups during the 1st yr.

Forty-eight elderly patients with uncomplicated mild essential hypertension entered two drug regimens. In group 1, clonidine monotherapy (n = 15), clonidine was titrated to achieve goal blood pressure (less than 90 mm Hg diastolic) in dosages of 0.05 mg twice daily to 0.2 mg three times daily. Blood pressure decreased without major side effects (p less than 0.001). Three patients required small doses of diuretic after six months of clonidine monotherapy. In group 2, step-care therapy (n = 33), clonidine was added to chlorthalidone, 25 mg daily, for three weeks. Eight patients achieved the goal blood pressure with chlorthalidone, 25 required clonidine (0.1 mg to 0.3 mg twice daily) to achieve blood pressure control. Side effects of clonidine did not require discontinuation of therapy. Retrospective analysis of up to 2 1/2 years of clonidine plus diuretic (n = 51) showed a similar blood pressure reduction. Clonidine can be used effectively with or without a diuretic in the elderly hypertensive.

Rhesus monkey infants were marginally deprived of zinc (4 ppm diet) from conception and were compared to controls (100 ppm diet) during the first year of life in development of reflexes and motor patterns, mother-infant interaction, delayed response performance, discrimination learning and reversal, and open field behavior. Deficits in amount and variety of behavior were recorded in deprived infants; spontaneous locomotor activity was 50% below control levels in males at 1 mo of age; spontaneous activity was 7-10% lower in both males and females at 3 mo of age; response latencies were 50% lower than controls at 7-9 mo; failure to reach discrimination reversal criterion was seen in 71% of deprived infants as compared to 10% of controls at 10 mo of age; and abnormally low levels of climbing and exploration were seen in two of six deprived infants at 12 mo of age. No abnormalities in the rate of behavioral development or in emotional adaptability were observed. These and other results suggest that syndromes of lethargy, apathy, and hypoactivity are characteristic of behavioral effects of marginal zinc deprivation in primates.

Studies of marginal zinc deficiency in rhesus monkeys have demonstrated that plasma Zn levels are often a poor indication of Zn status. To better assess the Zn status of these animals, we examined their liver concentration of Zn as well as of other minerals, metallothionein (MT), and superoxide dismutase (SOD). Liver-wedge biopsies were obtained from adult rhesus monkeys fed for 15 mo, either a control (100 micrograms Zn/g) or a marginally Zn deficient diet (4 micrograms/g; ZD). Liver Zn and MT concentrations were lower in ZD monkeys than in controls whereas iron concentration was higher in ZD monkeys than in controls. Liver copper, manganese, and magnesium concentrations and activities of CuZnSOD and MnSOD were similar in the two groups. Data from the groups were pooled for regression analysis. Measurement of liver Zn and MT concentrations are useful in the assessment of the effects of long-term Zn deprivation in primates.

Rhesus monkeys were fed a diet marginally deficient in zinc (4 ppm zinc) throughout pregnancy and were monitored for changes in hematological, biochemical, and immunological parameters. This dietary zinc level was chosen because it did not produce an overt deficiency syndrome when fed for 10 wk to nonpregnant monkeys. Deprived animals were compared to control groups fed a zinc replete (100 ppm) diet ad libitum or on a food restricted (pair fed) basis. Beginning in the 3rd trimester zinc-deprived monkeys exhibited characteristic signs of deficiency including dermatitis, anorexia, and low levels of plasma zinc (less than 65 micrograms/100 ml) and of serum alkaline phosphatase activity. The extent of plasma zinc depression in deficient monkeys was dependent on total food intake; severely anorexic monkeys lost weight but maintained normal plasma zinc levels; monkeys that gained 20 to 30% of their body weight during pregnancy had severely depressed plasma zinc. Plasma vitamin A was reduced in the deprived group while copper, magnesium, and folate levels remained similar to controls. Hematological changes indicative of iron deficiency anemia (reduced packed cell volume, mean corpuscular volume, and Hb) were also seen in severely deficient monkeys. In addition, the peripheral lymphocyte mitogen response was reduced in deficient dams. We conclude that marginal deficiency of dietary zinc can produce significant abnormalities of nutritional status and has the potential for producing serious immunohematological dysfunction during pregnancy.

Adult nonpregnant female rhesus monkeys fed purified diets containing 100 or 4 ppm zinc for 1 yr were mated then studied through midgestation. At mating, zinc-deprived (ZD) monkeys showed maternal lymphocyte response to mitogens concanavalin A (Con A) and phytohemagglutinin (PHA), serum uric acid and carbon dioxide, and WBC lower than in control (C) monkeys. There was a significant positive association between plasma zinc and PHA response. At midgestation, discriminant analysis revealed that maternal lymphocyte response to Con A, fetal abdominal circumference (by ultrasound), plasma fibrinogen, serum IgM, and amniotic fluid iron level were discriminators for diet group, all lower in ZD than in C monkeys. Maternal plasma and RBC zinc at midgestation were positively associated with fetal growth and plasma uric acid. These observations suggest that immune function (ie, mitogen response and serum immunoglobulin level) is a strong discriminator of dietary zinc deprivation in rhesus monkeys, both before and during pregnancy.

A marginal state of zinc deficiency was induced in the pregnant nonhuman primate, Macaca mulatta, by feeding a diet containing 4 ppm zinc beginning at conception. Pregnancy outcome of marginally zinc-deficient monkeys (ZD) was compared to both pair-fed (PF) and ad libitum fed (AL) control animals (100 ppm zinc). Stillbirths, abortions, and delivery complications were more frequent in both ZD and PF dams than in AL controls; no malformations were detected (maternal plasma zinc was normal during organogenesis). Male ZD neonates weighed significantly less than same sex controls; also, in relation to colony norms, 7/8 ZD males, 2/8 ZD females, and 1/10 PF controls were of low birth weight. Further, plasma zinc and iron levels were lower in ZD neonates than in AL and PF controls. ZD neonates also had reduced muscle tonus. Birth weight and maternal plasma zinc concentration were negatively correlated in ZD group but positively correlated in AL and PF groups. Indeed, maternal plasma zinc concentration alone did not identify a state of zinc deficiency which impaired fetal growth in monkeys.

Arrested adolescent growth and sexual maturation are striking symptoms of severe dietary zinc deprivation. More general implications of mild or marginal Zn deficiency during adolescence are not known. Five marginally Zn-deprived (ZD) male monkeys (4 mg Zn/kg diet) were compared with five controls pair fed a diet containing 100 mg Zn/kg during early adolescence. Mean plasma Zn levels were 38% lower in ZD group than in controls when evaluations began. During rapid growth plasma Zn decreased in controls but not ZD animals. ZD animals had delayed onset of accelerated weight gain and linear growth; loss of subcutaneous fat typical of early adolescence did not occur. ZD monkeys required two to three times more trials for both learning and reversal a visual discrimination task. Immune function was depressed 20-30% as reflected in early reduced proliferative response of peripheral lymphocytes and later lower immunoglobulin levels. Marginal dietary Zn deprivation affects growth and function in adolescence without producing frank developmental retardation.

To assess long-term effects of marginal zinc deprivation on pregnancy, adult non-pregnant female rhesus monkeys were fed diets containing 100 or 4 ppm zinc for 1 yr. then mated; effects on pregnancy and its outcome are under study. During this year, food intake was not depressed in zinc-deprived (ZD) monkeys, and there were relatively few effects on biochemical or hematological indices. By the end of the year, plasma zinc concentration was somewhat lower in ZD monkeys than in controls. Several immune variables, including serum IgM and IgG levels and polymorphonuclear leukocyte (PMN) function, were depressed in the ZD group, changes closely reflecting circannual fluctuations in plasma zinc levels in both diet groups. Endotoxin-activated plasma from ZD monkeys had less potential to promote chemotaxis than that from control monkeys, suggesting that defective PMN function may relate to a plasma effect. Marginal zinc deprivation may thus influence immune function before other variables are affected.

Plasma renin activity (PRA) was measured during the administration of clonidine (0.1 mg twice daily) to 11 patients with essential hypertension. After eigth weeks a trend toward an increase in PRA was noted. This increase was significant in "low renin" subjects (less than 1 ng Al/ml/hr, n = 7) in whom PRA (ng/ml/hr +/- SEM) rose from a control value of 0.7 +/- 0.1 to 2.0 +/- 1.1 at one week, 5.6 +/- 2.1 at four weeks, and 4.4 +/- 1.0 at eight weeks (p less than 0.05). In contrast, in a small group of "normal renin" patients (n = 4), PRA did not change significantly but tended to decrease on clonidine therapy from 9.2 +/- 3.4 at control to 3.3 +/- 2.0 at one week, 3.4 +/- 0.6 at four weeks, and 4.7 +/- 1.7 ng Al/ml/hr at eight weeks. Plasma renin substrate and serum and urinary electrolytes did not change significantly in either group and blood pressure reduction was comparable in the two groups. A strong negative correlation (r = -0.84, p less than 0.001) was found between changes in creatinine clearance and changes in PRA. Previous studies have implicated alpha-adrenergic receptors as the site of clonidine actions on blood pressure and renin release. The observed renin stimulation during chronic administration of clonidine to "low renin" patients with essential hypertension may imply an altered intrarenal alpha-receptor function in "low renin" essential hypertension.

The relationship between dietary zinc, vitamin A, and retinol-binding protein (RBP) was studied in pregnant rhesus monkeys. Beginning on day 0 of gestation, monkeys were divided into three groups; 1) eight ad libitum-fed controls (AL) fed a diet containing 100 micrograms/g zinc, 2) 15 zinc-deprived (ZD) fed a diet containing 4 micrograms/g zinc, 3) 11 pair-fed controls (PF) fed the 100 micrograms/g control diet in amounts equal to those consumed by ZD animals. ZD monkeys had lower plasma zinc levels than did the AL and PF groups at day 135 of gestation, and at 1 and 3 months gestation. A positive correlation between plasma vitamin A and plasma zinc was observed (r = 0.5150, p less than 0.05) and between RBP and zinc (r = 0.883, p less than 0.001) in the ZD group at day 135 of pregnancy. By 3 months postpartum, plasma zinc levels increased in all groups; a positive correlation between zinc and vitamin A was observed in the ZD group (r = 0.5162, p less than 0.05) and in the PF group (r = 0.6353, p less than 0.05); however, no correlation between zinc and RBP was observed. In ZD monkeys, the ratio of RBP to vitamin A was higher (p less than 0.05) than in controls at day 135 of pregnancy. Polynomial regression of the interaction between plasma vitamin A and zinc, and the RBP/vitamin A and zinc, indicated a curvilinear relationship between plasma zinc and these two parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

The etiology of tumor-induced hypercalcemia was investigated in a transplantable Leydig cell tumor of the Fischer rat. In this model, serum calcium rose from a baseline of 10.4 +/0 0.3 mg/dl to 12.5 + 0.4 mg/dl at day 10 and 16.4 +/- 1.3 mg/dl (p less than 0.001) at day 13 post transplant. Urinary calcium also increased from 1.52 +/- 0.17 mg/d to 3.52 + 0.72 mg/d (Day 12, p less than 0.01). Serum phosphate decreased from a baseline of 7.5 +/- 0.3 mg/dl to 5.5 +/- 0.6 mg/dl at day 13 (p less than 0.05). At day 13 serum immunoreactive parathyroid hormone levels fell 76% from baseline (p less than 0.01). Calcitonin increased from 59 +/- 2 pg/ml to 88 +/- 9 pg/ml (p less than 0.02). The plasma prostaglandin E metabolite, 13,14-dihydro-15-keto-PGE2 increased from 407 +/- 103 pg/ml to 647 +/-62 pg/ml (p less than 0.05) and the active Vit D compound 1,25(OH)2D increased from 94.8 +/- 5.2 pg/ml to 162.3 +/- 11.8 pg/ml (p less than 0.01). Urinary cyclic AMP did not decrease in parallel with the parathyroid hormone level and, in fact, increased from 146 +/- 3 nmol/d to 172 +/- 27 nmol/d (NS). Administration of the cyclooxygenase inhibitor indomethacin (20 mg/Kg/d) or hydrocortisone (50 mg/Kg/d) did not prevent the development of hypercalcemia. This model is similar to many patients with humoral hypercalcemia of malignancy who demonstrate suppression of parathyroid hormone with elevated urinary cyclic AMP excretion and may prove useful in the understanding of the responsible mechanisms.

The possibility of permanent damage to brain function after developmental corticosteroid treatment has been raised in connection with therapeutic use of potent synthetic corticosteroids during the period of brain development in the human fetus and infant. In the present study, brain function was evaluated in rats treated during brain development with triamcinolone acetonide (TAC). A subtoxic dose (0.9 mg/kg), which did not retard growth, was used. TAC treatment at two periods of post-embryonic brain development (day 0 and day 10 postnatal) led to deviations from normal exploration strategies in a radial maze. Treatment on day 16 gestation was effective only in males. Neonatal TAC-treatment also affected spontaneous alternation in a T-maze. Measures which reflected arousal-activity levels during behavioral tests, such as time to initiate exploration and time to complete exploration, were not affected by treatment. These results suggest that the development of complex brain function in rats can be altered by subtoxic corticosteroid treatment in the perinatal period.

Skeletal maturation was evaluated from ages 1 to 3 y in rhesus monkeys that had been subjected to a diet marginally deficient in zinc (4 micrograms/g Zn) from conception through age 3 y. Skeletal development was assessed at 18, 24, 30, and 36 mo of age and compared with that of controls fed ad libitum. Skeletal maturation was determined by the presence of epiphyseal ossification centers. To evaluate endochondral bone mineralization the appearance of the zone of provisional calcification on the metaphyseal side of the growth plate and the width of the growth plate were observed. Marginal Zn deprivation was associated with delayed skeletal maturation in monkeys up to age 3 y. Defective mineralization of bone was evident in these monkeys up to age 6 mo. Between ages 6 mo and 3 y bone mineralization increased in some of the marginal-Zn monkeys to values that were only slightly below those for control monkeys.

The effect of a hypercalcemia-producing Leydig cell tumor on vascular reactivity in Fischer rats was studied. Seven to eight days after tumor implantation, there was no difference between tumor (T) and control (C) animals in serum calcium, serum phosphate, plasma catecholamine levels, mean arterial pressure (MAP), or blood pressure responses to norepinephrine (NE) infusion. At day 12-13 of tumor growth, the serum calcium in the tumor-bearing rats was significantly higher (12.2 +/- 0.8 vs. 9.7 +/- 0.3 mg%, P less than .01) and their serum phosphate significantly lower (4.5 +/- 0.3 vs. 5.7 +/- 0.4 mg%, P less than .01) than controls. Plasma epinephrine (E) (497 +/- 154 vs. 62 +/- 13 pg/ml, P less than .05), and norepinephrine (NE) (686 +/- 85 vs. 329 +/- 75 pg/ml, P less than .01) were markedly elevated in the tumor rats. MAP and the blood pressure responses to graded NE infusions were significantly lower in tumor animals at Day 12-13, whereas there was no change in sensitivity to angiotensin II (AII) infusions. In vitro contractile responses of tail artery segments to transmural nerve stimulation (TNS) in animals with tumors were lower than in controls but there were no differences in sensitivity to exogenous NE in vitro. These results suggest that the tumor stimulates production of a circulating factor which desensitizes NE receptors and that this tumor also decreases neurovascular function by an undefined mechanism.

Rhesus monkey infants fed a marginally zinc-deficient diet (4 ppm) from conception through 12 mo of postnatal life were monitored for changes in hematological, biochemical, and immunological parameters. These zinc-deprived (ZD) infants were compared to control infants whose mothers were fed a zinc-replete (100 ppm) diet either ad libitum (AL) or pair-fed (PF) throughout gestation and lactation. Blast transformation of peripheral blood lymphocytes to phytohemagglutinin (PHA-P), concanavalin A (Con A), and pokeweed mitogen (PWM), was dramatically depressed in the zinc-deficient (ZD) group. Similarly, ZD infants had reduced polymorphonuclear leukocyte function as measured by chemotaxis to endotoxin-activated plasma and phagocytosis of Candida albicans. Levels of serum IgM were significantly altered in zinc-deficient infants compared to controls. Serum concentrations of IgG and IgA were similar in zinc-deficient and control infants. ZD infants also manifested a hypochromic microcytic anemia at one month of age, reduced activity of the zinc metalloenzyme alkaline phosphatase, and lower activity of SGPT.

Neurobehavioral evaluations were conducted in neonatal monkeys (Macaca mulatta) exposed to narcotic analgesics during labor through their dams. Infants exposed to meperidine (2 mg/kg maternal dose) or alfentanil (0.1 mg/kg maternal dose) were compared with controls whose dams received no analgesic. Meperidine and alfentanil differ in pharmacologic properties related to maternal-fetal transfer and neonatal metabolism. Drug-exposed infants showed neurobehavioral effects over the first 3 days of life including depressed respiration (at birth), depressed environmental response to aversive stimuli (days 0, 1, and 2), more overnight sleep (day 1), and more quiet behavior patterns while awake (day 3). In addition, drug exposure was associated with increased elicited muscle tone early in the neonatal period and earlier maturation of sitting, standing, and walking. No effects on growth or health were noted, but drug-exposed infants had lower hematocrits and an earlier onset of a linear growth rate as reflected in body weight. No qualitative or quantitative differences were noted between the two drug treatments. Because behavioral effects were seen after the drug was eliminated, a direct pharmacologic action of the drug does not fully explain the findings.

Skeletal maturation was evaluated in newborn and infant rhesus monkeys that had been subjected to a marginally zinc-deficient diet (4 ppm zinc) from conception through 12 months of postnatal life. Serial radiographic assessment of skeletal development was performed and compared to both ad libitum and pair-fed controls. Radiographs were obtained at birth and at 1, 3, 9, and 12 months of age. In each age group a maturation indicator was selected to identify individuals with abnormal skeletal maturation defined on the basis of presence of epiphyseal ossification centers. Animals were compared only within a given sex group. Additionally, to evaluate endochondral bone mineralization, the appearance of the zone of provisional calcification on the metaphyseal side of the growth plate and the width of the growth plate were assessed. A marginal level of zinc deprivation during gestation and during the 1st yr of life was found to be associated with significantly delayed skeletal maturation and defective mineralization. This abnormality of bone mineralization has many features similar to human rachitic syndromes and suggests that zinc plays an important role in endochondral bone formation.

Infant monkeys (Macaca mulatta) exposed to narcotic analgesics during labor after treatment of dams were evaluated for growth and development over a 14-week period. Ten infants exposed to meperidine (2 mg/kg maternal dose) or alfentanil (0.1 mg/kg maternal dose) were compared with seven controls whose dams received no analgesic. No group differences in weight gain or body growth were observed. Alfentanil-exposed infants appeared to have a higher incidence of infections requiring veterinary treatment. Measures of spontaneous activity showed a significantly higher incidence of immature rest pattern (laying) in the alfentanil group associated with lower overall locomotor activity relative to controls. Meperidine-exposed infants had a generally higher overall level of locomotor activity than controls that was statistically significant at 11 weeks of age. Alfentanil-exposed animals were impaired in performance of a simple cognitive task (object constancy) at 2 to 3 months of age and meperidine-exposed infants showed a similar nonsignificant trend. Gross and fine motor maturations were similar to those of controls. Thus, in this situation, the impact of obstetric analgesic treatment was demonstrable for several months after birth in some limited areas.