Transneuronal transport of peroxidase-conjugated wheat germ agglutinin (WGA-HRP) from the olfactory epithelium to the brain of the adult rat

The sensory neurons of the olfactory epithelium, as a consequence of their odor detection function, contact both the external environment and the central nervous system. The possibility that substances applied to the epithelium might reach the central nervous system was investigated by the intranasal application of peroxidase-conjugated wheat germ agglutinin (WGA-HRP). WGA-HRP was transported through olfactory receptor axons to the glomerulus of the olfactory bulb. Reaction product was localized electron microscopically to tubulovesicular profiles and dense bodies in sensory axons. Evidence of transneuronal transport was indicated by reaction product localized in dense bodies in dendrites postsynaptic to receptor cell axons. Periglomerular, tufted and mitral cells in the olfactory bulb also were transneuronally labeled. Anterograde transneuronal labeling occurred in the olfactory tubercle, piriform cortex and surrounding the lateral olfactory tract. Retrograde transneuronal label was found in neurons of the basal forebrain with the largest number of perikarya in the lateral nucleus of the horizontal limb of the diagonal band, a major source of cholinergic afferents to the olfactory bulb. These data suggest that substances, specifically those which bind to receptors, are transported from the olfactory receptor neurons in the nasal epithelium to the brain. Thus, the olfactory system may provide a route of entry for exogenous substances to the basal forebrain.

Blood vitamin and choline concentrations in healthy domestic cats, dogs, and horses

Blood concentrations of thiamin, biotin, nicotinates, pantothenates, folates, riboflavin, vitamins A, B6, B12, C, E, beta-carotene and choline were analyzed in healthy animals (23 horses, 25 dogs, and 29 cats). B-Complex vitamins and choline also were analyzed in the liver of the dogs and cats. Vitamin concentrations in the blood and livers of dogs were similar; however, blood vitamin A and beta-carotene concentrations were lower in the cat than in the dog. Horses had a higher B12 blood concentration than did the dogs and cats. These data can be useful for detecting overt and hidden vitamin deficits in these species due to various conditions.

Electrophysiologic features of abetalipoproteinemia: functional consequences of vitamin E deficiency

We performed electrophysiologic testing in 10 patients with abetalipoproteinemia (ABL). Peripheral nerve studies implied an axonal disorder. Visual evoked potentials demonstrated prolonged P100 latency in three patients and abnormal electroretinograms in six. Somatosensory evoked potentials indicated dorsal column dysfunction in eight patients. Brainstem auditory evoked potentials were normal. Findings were consistent with the known neuropathology of ABL and of experimental vitamin E deficiency. Stabilization or improvement in electrophysiologic findings occurred with vitamin E supplementation. Neurophysiologic tests document retinal, central somatosensory and peripheral nerve lesions in vitamin E deficiency and provide an objective indication of response to treatment.

Comparison of plasma alpha and gamma tocopherol levels following chronic oral administration of either all-rac-alpha-tocopheryl acetate or RRR-alpha-tocopheryl acetate in normal adult male subjects

Vitamin E was administered orally (400 IU twice a day) to adult male humans for 28 days as either dl-alpha-tocopheryl acetate (all-rac-alpha-tocopheryl acetate) or d-alpha-tocopheryl acetate (RRR-alpha-tocopheryl acetate). Plasma alpha-tocopherol rose rapidly and fell at the same rate following cessation of supplementation with both forms of vitamin E. No significant differences in plasma alpha- or gamma-tocopherol levels were found between the two forms of vitamin E following their administration. The results confirm the currently accepted biopotencies of 1.0 IU/mg and 1.36 IU/mg, respectively for the two forms of vitamin E. Supplementation with either form of alpha-tocopheryl acetate resulted in depressing plasma gamma-tocopherol to less than 1/3 of initial levels; also the gamma/alpha ratio was depressed to less than 1/7 of the initial value. The study suggests that the gamma/alpha vitamin E ratio might also serve as a sensitive index of alpha-tocopherol ingestion.

Anatomical evidence for interactions between catecholamine- and adrenocorticotropin-containing neurons

Recent studies suggest that neurons containing adrenocorticotropin and catecholamines are localized to similar areas of the brain. In this immunocytochemical study, the distributions of neurons and terminals containing adrenocorticotropin and tyrosine hydroxylase, the first enzyme in the catecholamine biosynthetic pathway, were compared using the peroxidase-antiperoxidase technique. Neurons containing adrenocorticotropin and tyrosine hydroxylase formed overlapping hyperbolic lamina in the mediobasal hypothalamus. Although adrenocorticotropin and tyrosine hydroxylase containing neurons often formed small clusters, no double labeled cells were observed. Overlap also occurred between adrenocorticotropin and tyrosine hydroxylase terminal fields in several diencephalic nuclei including the periventricular hypothalamic gray and paraventricular thalamus. In contrast, other regions displayed striking compartmentalization of terminal fields; for example, in both the paraventricular hypothalamus and central nucleus of the amygdala, adrenocorticotropin was located in ventral and tyrosine hydroxylase in more dorsal aspects of the nuclei. Adjacent sections also showed a close correspondence between adrenocorticotropin terminals and tyrosine hydroxylase cell bodies in paraventricular, periventricular, dorsomedial and ventral hypothalamic nuclei. These data provide anatomical substrates for potential functional interactions between catecholamine and adrenocorticotropin systems in forebrain.

Determination of metabolically active B12 and inactive B12 analog titers in human blood using several microbial reagents and a radiodilution assay

Metabolically active B12 analogs and inactive B12 analogs were measured in plasma, red blood cells (RBC), and pooled pernicious anemia serum. B12 values by Lactobacillus leichmannii, Escherichia coli, Euglena gracilis, and radioisotope dilution method (RIDA) as assays for total B12 (active analogs + inactive analogs) were compared to Ochromonas malhamensis values as index of only metabolically active B12. B12 values above those with O malhamensis distinguished inactive analogs from active B12. Inactive analogs contribute 85, 97, 135, and 163% above active B12 activity in normal plasma when E gracilis, L leichmannii, RIDA, and E coli, respectively, were used for B12 analysis. RIDA B12 determinations for active B12 in plasma showed that 44% of the B12 measured was still due to inactive analogs when compared to O malhamensis B12 activity. Inactive B12 analogs contributed 21, 151, and 224% above O malhamensis active B12 in RBC when E gracilis, L leichmannii, and E coli, respectively, were used.

Evaluation of insecticide residues and droplet drift following aerial application to cotton in New South Wales

In a study to determine the extent of off target drift from aerial spraying, insecticides were applied to cotton crops in various strengths of crosswind by an aircraft fitted with rotary atomizers. Both water-based and oil-based sprays were applied, at 20 and 2 litres/ha respectively. Compared with the mean insecticide deposit across a 16-m target swath, in seven runs, the mean recoveries of insecticide 15, 165 and 3 15 m downwind from the edge of the swath were 6.8, 0.13 and 0.002% respectively. Deposition on plants was nearly twice that on the ground, but the proportional decline downwind was similar. Counts of droplets deposited on paper targets fixed to masts showed that the dispersing cloud of water-based spray contracted more rapidly than did that of the oil-based spray, probably because of greater evaporation of the former. The results indicate that a 300-m wide buffer zone between target crops and areas susceptible to contamination should be adequate under most conditions.

Strain differences in pituitary prolactin content: relationship to number of hypothalamic dopamine neurons

BALB/cJ mice have more tuberoinfundibular dopamine neurons, and thus greater tyrosine hydroxylase activity, than CBA/J mice. Strain differences in the synthesis and release of prolactin would also be predicted since dopamine released from the tuberoinfundibular neurons is the prolactin inhibitory factor which plays a role in the regulation of both prolactin synthesis and release. As expected, CBA/J mice, with fewer dopamine neurons, synthesized and released significantly more prolactin than BALB/cJ mice; that is, both pituitary and serum prolactin concentrations were greater in CBA/J mice. To determine if there were more cells containing prolactin or more prolactin per cell, pituitaries were stained with antibodies to prolactin and densitometric analysis made of both the average staining per unit area and total staining per pituitary. For both indices CBA/J mice had more staining than BALB/cJ mice. Using these criteria the difference in staining was attributed to more prolactin-stained lactotrophs in the CBA/J strain. Although no differences in the number of acidophils demonstrated by Pearse Trichrome method were observed, acidophils from BALB/cJ mice appeared smaller and contained less cytoplasm than those from CBA/J mice. We conclude that strain differences in the number of tuberoinfundibular dopamine neurons are inversely related to the number of immunocytochemically demonstrable prolactin-containing cells in the anterior pituitary.

Genetic effects and sexual dimorphism in tyrosine hydroxylase activity in two mouse strains and their reciprocal F1 hybrids

This study further analyzed the environmental and genetic mechanisms underlying the previously reported strain differences in tyrosine hydroxylase (TH) activity in the nigrostriatal and hypothalamic dopamine system of the BALB/cJ (B) and CBA/J (C) inbred mouse strains and related behavioral processes using parental and reciprocal F1 hybrid generations. Significant strain differences were found in both sexes in all the measured characters. Comparing males and females, sexual dimorphisms were found in TH activity of substantia nigra (SN), corpus striatum (CS) and hypothalamus (H), and in exploratory behavior (IE). Presence of sexual dimorphism was genotype dependent, with the exception of TH activity in H. Major components of strain differences, maternal effects and additive gene effects, were separated by biometrical genetic methods. The analysis indicated that significant maternal effects were present in TH activity of TH and CS with a trend towards this phenomenon in the SN. Additive gene effects were significant in all characters and various degrees of dominance were expressed in the hybrids in TH activity of SN and CS, as well as in behavioral traits, IE and spontaneous locomotion (SL). All the biochemical and behavioral parameters were expressed at lower levels in CBA/J than in BALB/cJ mice and reciprocal F1 hybrids took intermediate positions between the two parental strains for all phenotypes examined, with the exception of IE, where complete dominance was found in (CXB)F1 females. These results are consistent with the hypothesis that some of the genes affecting TH activity in brain dopamine systems contribute to the expression of dopamine mediated behaviors. Our analysis also indicates the possibility that the maternal effects on TH activity in CS and SN are the consequences of X-chromosome linked gene effects. We suggest that the influence of the X-chromosome linked gene(s) is dependent upon the action of gonadal steroids during the critical period of ontogenesis, and X-chromosome linked gene(s) play a major role in the genotype dependent expression of sexual dimorphism in TH activity.

Number of dopamine neurons predicts prolactin levels in two inbred mouse strains

Mice of the BALB/cJ strain have more dopamine neurons than mice of the CBA/J strain. We now report that BALB/cJ mice have less circulating and pituitary prolactin than CBA/J mice, a relationship expected from the difference in tuberoinfundibular dopamine neuron number.

Biotin deficiency complicating parenteral alimentation: diagnosis, metabolic repercussions, and treatment

Biotin deficiency associated with total parenteral nutrition is an emerging clinical problem; criteria for diagnosis and dosage for treatment are unclear. We have diagnosed and successfully treated biotin deficiency in three patients. Each patient had alopecia totalis, hypotonia, and developmental delay. Two developed the characteristic scaly periorificial dermatitis; one had only an intermittent scaly rash on the cheeks and occipital scalp. Zinc and essential fatty acid supplements were adequate; serum zinc levels and triene/tetraene ratios confirmed sufficiency of these nutrients. None of the patients received biotin prior to diagnosis, and each had decreased excretion of urinary biotin and increased urinary excretion of organic acids diagnostic of deficiency of two biotin-dependent enzymes (methylcrotonyl-coenzyme A carboxylase and priopionyl-coenzyme A carboxylase). Only one patient had a plasma biotin concentration below the normal range (Ochromonicas danica assay). The rash, alopecia, and neurologic findings responded dramatically to biotin therapy (100 micrograms/day in all patients; an initial larger dose of 1 mg/day for 1 week plus 10 mg/day for 7 weeks in one patient), and did not recur. However, abnormal organic acid excretion persisted in one patient who did not receive the larger dose. We conclude that plasma biotin concentration does not reflect biotin status in all cases and speculate that the biotin supplement currently recommended for pediatric patients (20 micrograms/day) may not be adequate therapy for biotin deficiency and might not even be adequate to maintain normal biotin status during TPN.

A Nutritional and Hematologic Assessment of Elite Ballet Dancers

In brief: We studied the nutritional and hematologic status of 22 professional ballet dancers (10 men, 12 women, mean age 25), from American Ballet Theatre by analyzing daily dietary intake and laboratory data including blood vitamin assays. The dancers had law percent body fat. Daily calorie intake was 2,967 ± 667 kcal for men and 1,673 ± 450 kcal for women. Carbohydrate consumption (38% of the total daily calorie intake for men and 50% for women) was too law for efficient energy use. Hemoglobin and red cell indexes were normal, but serum ferritin was below normal in eight women and three men. Serum chemistry values were normal. Blood vitamin assays were normal in all dancers, reflecting widespread use of vitamin supplements. By sports medicine standards, the dancers' law calorie diets were suboptimal for strenuous physical exercise.

Pyridoxine deficiency in children treated with isoniazid

Isoniazid-induced deficiency of pyridoxine (vitamin B6) is reportedly not uncommon in adults but rare in children. In the present study, 38 children had serum levels of pyridoxine tested while receiving therapy with isoniazid. A biologic assay using the protozoan Tetrahymena thermophila determined pyridoxine status after 2 to 18 months of therapy with isoniazid. Five children (13 percent) were deficient. None had definitive clinical symptoms or signs consistent with pyridoxine deficiency. Three had normal nerve conduction velocity. Children receiving isoniazid in dosages greater than 10 mg/kg/day had a higher incidence of deficiency. Present recommendations for withholding pyridoxine prophylaxis from children receiving isoniazid therapy must be reconsidered in light of these findings, particularly in those children who are debilitated or have a poor nutritional history with a known pyridoxine deficit prior to therapy with isoniazid.

Blood vitamin levels of long-term adult home total parenteral nutrition patients: the efficacy of the AMA-FDA parenteral multivitamin formulation

Although the AMA-FDA parenteral adult multivitamin formula is now widely used, there are no published data on the efficacy of this formulation in maintaining adequate vitamin nutriture in patients on long-term parenteral nutrition. Blood levels of its constituent nutrients were determined in 16 clinically stable home total parenteral nutrition patients with severe gastrointestinal dysfunction, the majority of whom had been on home total parenteral nutrition for 1 to 9 yr and most of whom were ingesting some food orally. The daily formula (MVI-12) was added to the basic total parenteral nutrition formula in 2-day batches; the vitamins were thus infused approximately 3 hr after preparation on day 1 and after 27 hr on day 2. The duration of infusions was from 8 to 16 hr. Blood was drawn approximately 36 hr after completion of the last vitamin infusion. Plasma, trichloroacetic acid-treated plasma, and whole blood were frozen until analyzed for the vitamins by microbiologic or chemical methods. All vitamin levels, except for vitamin D metabolites, were measured four times in each patient between the 4th and 36th wk while receiving daily MVI-12. Single determinations of 25-OH and 1:25 (OH)2 vitamin D were made in eight of the 16 patients between the 61st and 84th wk while on MVI-12. Repeat values during this extended period were also made on five of the patients for vitamins A and E. These values were compared with serum vitamin levels obtained on an earlier formulation (MVI concentrate, Berocca C, and folate each given twice weekly and B12 given once weekly). The AMA-FDA formula given daily maintained blood levels above the lower normal limits for most of its constituent vitamins and vitamin D metabolites for the great majority of stable home total parenteral nutrition adults with unexplained occasional exceptions. However, almost half of the vitamin A levels and some of the pantothenate and biotin values were above the normal range; these tended to be associated with the presence of renal disease. Ascorbic acid and thiamin levels tended to be clustered in the lower normal range. Because of evidence for loss of ascorbic acid standing in total parenteral nutrition solutions for 24 hr prior to infusion, it is recommended that the vitamin formulation be added to the total parenteral nutrition solution just prior to infusion.

Blind loop syndrome, vitamin E malabsorption, and spinocerebellar degeneration

A 72-year-old man had severe malabsorption, progressive retinopathy, and spinocerebellar degeneration 32 years after gastric surgery, blind loop formation, and intestinal bacterial overgrowth. Clinical and pathologic features were typical of vitamin E deficiency; vitamin E was nearly undetectable in serum and profoundly low in adipose tissue. Vitamin E blood levels initially improved on treatment with antibiotics; after additional vitamin E supplementation, there was clinical improvement.

Does UV-A potentiate 'short contact' dithranol therapy?

The effect of ultraviolet-A (UV-A) irradiation in combination with 'short contact' dithranol treatment was studied in ten patients with chronic plaque psoriasis. Increasing concentrations of dithranol were applied daily to the psoriatic plaques on both sides of the body. One side was irradiated with UV-A daily. There was no difference in the rate of clearance between the two sides. The effectiveness of 'short contact' dithranol was confirmed.