Miniaturized Raman instrumentation detects carotenoids in Mars-analogue rocks from the Mojave and Atacama deserts

This study is primarily focused on proving the potential of miniaturized Raman systems to detect any biomolecular and mineral signal in natural geobiological samples that are relevant for future application of the technique within astrobiologically aimed missions on Mars. A series of evaporites of varying composition and origin from two extremely dry deserts were studied, namely Atacama and Mojave. The samples represent both dry evaporitic deposits and recent evaporitic efflorescences from hypersaline brines. The samples comprise halite and different types of sulfates and carbonates. The samples were analysed in two different ways: (i) directly as untreated rocks and (ii) as homogenized powders. Two excitation wavelengths of miniaturized Raman spectrometers were compared: 532 and 785 nm. The potential to detect carotenoids as biomarkers on Mars compared with the potential detection of carbonaceous matter using miniaturized instrumentation is discussed.

The Capacity of Humans to Identify Components in Complex Odor–taste Mixtures

Despite the fact that humans experience mixtures of odors and tastes each time they eat, little is known of their capacity to detect the individual components of foods. To investigate this capacity, 43 subjects were trained to identify three odors and three tastes and were required to indicate which of these could be identified in stimuli consisting of one to six components. Although the odor and taste components of most binary mixtures were identified, subjects encountered substantial difficulties with more complex mixtures with only two components being identified in the four- to six-component mixtures. In general, tastes were more easily identified than smells and were the only stimuli identified in the five- to six-component mixtures. Several mechanisms are proposed to account for the poor identification of components.

Relationship between molecular structure, concentration and odor qualities of oxygenated aliphatic molecules

Increasing the concentration of an odorant increases the number of receptor cells and glomeruli in the olfactory bulb that are stimulated, and it is commonly acknowledged that these represent increased numbers of receptor types. Currently, it is not known whether a receptor type is associated with a unique quality and a unique molecular feature of an odorant, or its activation is used by the brain in a combinatorial manner with other activated receptor types to produce a characteristic quality. The present study investigated the proposal that a molecular feature common to several aliphatic odorants and known to be the key feature required to stimulate the same mitral cells in the olfactory bulb results in a quality that is common to the odorants. Since the common structural feature may activate a specific receptor type possibly at a similar concentration, the qualities of the odorants were determined at seven concentrations where the lowest and highest concentrations were the detection threshold (DT) and 729DT of each subject. A list of 146 descriptors was used by 15 subjects to describe the qualities of each odorant at each concentration. The results indicate that each of the five odorants was characterized by different qualities and the qualities of four of the odorants changed with changes in concentration. Importantly, no quality common to each of the odorants that had the same molecular feature could be identified and it is proposed that identification of the odorants occurs via a combinatorial mechanism involving several types of receptors.

A psychophysical study of the relationship between temporal processing in odor mixtures and transduction pathways

Depending on the odorant, transduction during the olfactory reception process is reported to be mediated by the second messengers cyclic adenosine 3',5'-monophosphate (cAMP) or inositol 1,4,5-triphosphate (IP(3)). The present study with humans investigates the relationship between temporal processing in mixtures and the type of transduction process used. The most common outcomes were reciprocal temporal interactions which were primarily dependent on odorant concentration and independent of the type of transduction process. The results are consistent with the bulk of evidence that each receptor neuron commonly has only one type of receptor.

Identification of the components of taste mixtures by adults and children

Recently, it was reported that cognitive factors may have impeded the analysis of binary taste mixtures by 8- to 9-year-old children, resulting in them identifying only the strongest component in each mixture compared to adults who identified both components (Oram, Laing, Freeman, & Hutchinson, 2001). The current study aimed to overcome this limitation by employing different training procedures and different instructions when conducting the task. In particular, the training involved familiarization with the two stimuli at several levels of perceived intensity to facilitate identification of the varying levels of each stimulus in mixtures. Using a selective attention procedure, adults and children were required to identify the components of stimuli that contained water, sucrose (sweet), sodium chloride (salty), or were binary mixtures of these two tastants. Both groups were successful in identifying the component(s) in each stimulus, demonstrating the importance of appropriate training and test procedures when studying the sensory responses of children. Together with data from the earlier study by Oram et al. (2001) it is concluded that 8- to 9-year-olds have the cognitive skills to analyze taste mixtures in terms of the identity of the components and their perceived strengths.

Functional occlusion: II. The role of articulators in orthodontics

Opinion is divided on whether there is a place for the use of semi-adjustable dental articulators in orthodontics. In this review we explore the validity and reproducibility of the techniques involved in mounting study models on a semi-adjustable dental articulator. We also look at the role of articulated study models in orthodontic diagnosis and treatment planning, in the finishing stages of orthodontics and in planning for orthognathic surgery. We report that each of the many stages involved in mounting study models on a semi-adjustable articulator is a potential source of error and that only if the technique is carried out with a high degree of accuracy is it worth the additional chairside time.

Antitumor benzothiazoles. 14. Synthesis and in vitro biological properties of fluorinated 2-(4-aminophenyl)benzothiazoles

Synthetic routes to a series of mono- and difluorinated 2-(4-amino-3-substituted-phenyl)benzothiazoles have been devised. Whereas mixtures of regioisomeric 5- and 7-fluoro-benzothiazoles were formed from the established Jacobsen cyclization of precursor 3-fluoro-thiobenzanilides, two modifications to this general process have allowed the synthesis of pure samples of these target compounds. Fluorinated 2-(4-aminophenyl)benzothiazoles were potently cytotoxic (GI(50) < 1 nM) in vitro in sensitive human breast MCF-7 (ER+) and MDA 468 (ER-) cell lines but inactive (GI(50) > 10 microM) against PC 3 prostate, nonmalignant HBL 100 breast, and HCT 116 colon cells. The biphasic dose-response relationship characteristically shown by the benzothiazole series against sensitive cell lines was exhibited by the 4- and 6-fluoro-benzothiazoles (10b,d) but not by the 5- and 7-fluoro-benzothiazoles (10h,i). The most potent broad spectrum agent in the NCI cell panel was 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (10h) which, unlike the 6-fluoro isomer (10d), produces no exportable metabolites in the presence of sensitive MCF-7 cells. Induction of cytochrome P450 CYP1A1, a crucial event in determining the antitumor specificity of this series of benzothiazoles, was not compromised. 10h is currently the focus of pharmaceutical and preclinical development.

Analysis of taste mixtures by adults and children

Children at mid-childhood (8-9 years), have limited perceptual-attentional skills to analyze complex stimuli (Shepp, Barrett, & Kolbet, 1987), and little is known of their skills to analyze chemosensory stimuli. Accordingly, this study investigated the ability of adults and 8-9 year old children to perceive tastes in binary mixtures. In Experiment 1, subjects used a selective attention procedure to indicate whether sweet, salty, and sour tastes were present in stimuli consisting of sucrose (sweet), sodium chloride (salty), citric acid (sour), and all possible binary mixtures of these tastants. Adults correctly recognized the two tastes in all mixtures, whilst children recognized only one in each mixture. Children were successful in recognizing sweet in both sweet-containing mixtures and salty in the sodium chloride-citric acid mixture. In Experiment 2, subjects used a similar selective attention paradigm to assess the perceived intensity of the three tastes in the above single and two-component stimuli. Suppression of one or both components was recorded with most mixtures by both age groups. However, with the mixture sodium chloride-citric acid, only the children recorded suppression of sourness, whilst for adults only saltiness was suppressed. In neither mixture containing sourness did children report suppression of sweetness or saltiness. It is concluded that at mid-childhood humans have difficulty analyzing taste mixtures into their components, due to attentional and possibly gustatory shortcomings.

Evidence for a genetic predisposition towards acute rejection after kidney and simultaneous kidney-pancreas transplantation

BACKGROUND

In vitro production of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin 10 (IL-10), and transforming growth factor-beta (TGF-beta) correlate with their respective genetic polymorphisms. We analyzed the relationship between these genetic polymorphisms and posttransplant outcome.

METHODS

Using DNA polymerase chain reaction (PCR) technology, polymorphisms for TNF-alpha, IFN-gamma, IL-10, and TGF-beta were determined for 82 kidney (K) and 19 simultaneous kidney-pancreas (SKP) recipients. These results were analyzed with regard to the incidence of acute rejection (AR), and the timing and severity of the first AR episode.

RESULTS

A high TNF-alpha production phenotype correlated with recurrent acute rejection (AR) episodes (P<0.026). Compared with the low TNF-alpha production phenotype, more patients with the high production phenotype had a post-AR serum creatinine >2.0 mg/dl, but this was not statistically significant (64 vs. 35%, P=0.12). There was no relationship between TNF-alpha genotype and the time to first AR episode or incidence of graft loss. IFN-gamma production phenotype showed no correlation with any of these clinical outcome parameters. There was an increase in AR incidence as the IL-10 production phenotype increased (low, intermediate, high), but only in low TNF-alpha producer phenotypes (P=0.023).

CONCLUSIONS

Patients with a polymorphic cytokine genotype putatively encoding for high in vivo TNF-alpha production, and to a lesser extent IL-10 cytokine genotypes putatively encoding for higher levels of in vivo IL-10 production, had a worse clinical outcome regarding AR episodes. These data support the hypothesis that the strength of alloimmune responsiveness after transplantation in part is genetically determined.

Antitumor benzothiazoles. 8. Synthesis, metabolic formation, and biological properties of the C- and N-oxidation products of antitumor 2-(4-aminophenyl)benzothiazoles

2-(4-Aminophenyl)benzothiazoles 1 and their N-acetylated forms have been converted to C- and N-hydroxylated derivatives to investigate the role of metabolic oxidation in the mode of action of this series of compounds. 2-(4-Amino-3-methylphenyl)benzothiazole (1a, DF 203, NSC 674495) is a novel and potent antitumor agent with selective growth inhibitory properties against human cancer cell lines. Very low IC(50) values (<0.1 microM) were encountered in the most sensitive breast cancer cell lines, MCF-7 and T-47D, whereas renal cell line TK-10 was weakly inhibited by 1a. Cell lines from the same tissue origin, MDA-MB-435 (breast), CAKI-1 (renal), and A498 (renal), were insensitive to 1a. Accumulation and metabolism of 1a were observed in sensitive cell lines only, with the highest rate of metabolism occurring in the most sensitive MCF-7 and T-47D cells. Thus, differential uptake and metabolism of 1a by cancer cell lines may underlie its selective profile of anticancer activity. A major metabolite in these sensitive cell lines has been identified as 2-(4-amino-3-methylphenyl)-6-hydroxybenzothiazole (6c). Hydroxylation of 1a was not detected in the homogenate of previously untreated MCF-7, T-47D, and TK-10 cells but was readily observed in homogenates of sensitive cells that were pretreated with 1a. Accumulation and covalent binding of [(14)C]1a derived radioactivity was observed in the sensitive MCF-7 cell line but not in the insensitive MDA-MB-435 cell line. The mechanism of growth inhibition by 1a, which is unknown, may be dependent on the differential metabolism of the drug to an activated form by sensitive cell lines only and its covalent binding to an intracellular protein. However, the 6-hydroxy derivative 6c is not the 'active' metabolite since, like all other C- and N-hydroxylated benzothiazoles examined in this study, it is devoid of antitumor properties in vitro.

Polymorphic haplotypes of the interleukin-10 5' flanking region determine variable interleukin-10 transcription and are associated with particular phenotypes of juvenile rheumatoid arthritis

OBJECTIVE

To determine the distribution of the interleukin-10 (IL-10) 5' flanking region haplotypes in children with arthritis and in controls, and to investigate the functional significance of each haplotype.

METHODS

Sequence-specific oligonucleotide probing was used to determine haplotype frequency. Transient transfection studies were used to investigate the transcription of reporter genes driven by each haplotype. Whole blood cultures were performed to assess IL-10 production by each genotype.

RESULTS

Patients with arthritis involving >4 joints were more likely to have a genotype with an ATA haplotype than those whose arthritis remained restricted to <4 joints. This ATA haplotype was associated with lower transcriptional activity than the GCC haplotype (P = 0.02), and the ATA/ATA genotype was associated with lower IL-10 production under lipopolysaccharide stimulation than other genotypes (P < 0.02).

CONCLUSION

The results of this study demonstrate the functional significance of the ATA haplotype and reveal a significant association of genotypes containing this haplotype with extended oligoarthritis.

Polymorphic haplotypes of the interleukin-10 5' flanking region determine variable interleukin-10 transcription and are associated with particular phenotypes of juvenile rheumatoid arthritis

OBJECTIVE

To determine the distribution of the interleukin-10 (IL-10) 5' flanking region haplotypes in children with arthritis and in controls, and to investigate the functional significance of each haplotype.

METHODS

Sequence-specific oligonucleotide probing was used to determine haplotype frequency. Transient transfection studies were used to investigate the transcription of reporter genes driven by each haplotype. Whole blood cultures were performed to assess IL-10 production by each genotype.

RESULTS

Patients with arthritis involving >4 joints were more likely to have a genotype with an ATA haplotype than those whose arthritis remained restricted to <4 joints. This ATA haplotype was associated with lower transcriptional activity than the GCC haplotype (P = 0.02), and the ATA/ATA genotype was associated with lower IL-10 production under lipopolysaccharide stimulation than other genotypes (P < 0.02).

CONCLUSION

The results of this study demonstrate the functional significance of the ATA haplotype and reveal a significant association of genotypes containing this haplotype with extended oligoarthritis.

Perception of sweetness in simple and complex taste stimuli by adults and children

Currently, there is little information on the ability of children to analyse complex chemosensory stimuli in terms of the presence and magnitude of the components. The present study investigates this question by comparing the ability of 95 adults and 8- to 9-year-olds to estimate the sweetness of several concentrations of sucrose in water and in three foods, namely, orange drink, custard and shortbread biscuits, using a magnitude estimation procedure. The results indicated that similar response functions were produced by adults and children for the sweetness of aqueous solutions of sucrose, custard and biscuits, but not for orange juice, where the functions produced by both female and male children were significantly flatter than those of the adults. Stimulus context may have influenced the ratings of children in the no-sucrose and highest sucrose concentration conditions with two of the foods. The absence of differences between the response functions of the female and male children with all types of stimuli indicated that gender had no influence on their responses. It is concluded that, at mid-childhood, humans are capable of estimating the sweetness of sucrose in foods, but that they have a tendency to limit the range of numbers used in their estimates of sweetness at high concentrations of sucrose in some foods.

Polymorphic haplotypes of the interleukin-10 5' flanking region determine variable interleukin-10 transcription and are associated with particular phenotypes of juvenile rheumatoid arthritis

OBJECTIVE

To determine the distribution of the interleukin-10 (IL-10) 5' flanking region haplotypes in children with arthritis and in controls, and to investigate the functional significance of each haplotype.

METHODS

Sequence-specific oligonucleotide probing was used to determine haplotype frequency. Transient transfection studies were used to investigate the transcription of reporter genes driven by each haplotype. Whole blood cultures were performed to assess IL-10 production by each genotype.

RESULTS

Patients with arthritis involving >4 joints were more likely to have a genotype with an ATA haplotype than those whose arthritis remained restricted to <4 joints. This ATA haplotype was associated with lower transcriptional activity than the GCC haplotype (P = 0.02), and the ATA/ATA genotype was associated with lower IL-10 production under lipopolysaccharide stimulation than other genotypes (P < 0.02).

CONCLUSION

The results of this study demonstrate the functional significance of the ATA haplotype and reveal a significant association of genotypes containing this haplotype with extended oligoarthritis.

Digital cameras and orthodontics: an overview

The need to record clinical images, for use in documenting treatments, patient education, patient contracting, referral letters and sharing information with colleagues, is increasing. This article reviews the advantages and disadvantages of 35 mm and digital photography.

Antitumor benzothiazoles. 7. Synthesis of 2-(4-acylaminophenyl)benzothiazoles and investigations into the role of acetylation in the antitumor activities of the parent amines

2-(4-Aminophenyl)benzothiazoles display potent and selective antitumor activity against inter alia breast, ovarian, colon, and renal cell lines, but their mechanism of action, though yet to be defined, may be novel. Metabolism is suspected to play a central role in the mode of action of these benzothiazoles since drug uptake and biotransformation were observed in sensitive cell lines (e.g., breast MCF-7 and MDA 468 cells) in vitro, whereas insensitive cell lines (e.g., prostate PC 3 cells) showed negligible uptake and biotransformation. N-Acyl derivatives of the arylamines have been synthesized, and in vitro studies confirm N-acetylation and oxidation as the main metabolic transformations of 2-(4-aminophenyl)benzothiazoles, with the predominant process being dictated by the nature of the 3'-substituent. The prototype amine 3 underwent mainly N-acetylation in vitro, while 3'-substituted analogues 4 and 5 were primarily oxidized. N-Acetylation of 4 to 11 exerts a drastic dyschemotherapeutic effect in vitro, but acetylation of the halogeno congeners 5-7 gave acetylamines 12-14 which substantially retain selective antitumor activity. In vivo pharmacokinetic studies in rats confirmed rapid and exclusive N-acetylation of the 3'-methyl analogue 4, but less acetylation with the 3'-chloro analogue 5. Distinct expression patterns of N-acetyltransferase NAT1 and NAT2 have been demonstrated in our panel of cell lines.

The development of meat-eating habits during childhood in Australia

The development of meat-eating habits of 999 Australian children between 1 and 16 years of age stratified across socioeconomic groups, was determined using a 4-day diary and measurement procedures to document intake. The results indicated that a stable pattern of meat-eating behaviour, as regards the frequency and type of meat eaten was established during the period 1-4 years of age and remained until 10-12 years for males and until at least 14-16 years for females. In contrast, the amount of meat consumed increased with age, the greatest increases occurring with adolescent males who ate the largest amounts of beef, chicken and pork. It is suggested that the early establishment of meat-eating habits may reflect a more general effect that may occur with other types of food.

Temporal processing of odor mixtures reveals that identification of components takes precedence over temporal information in olfactory memory

Temporal processing of binary mixtures results in odorants being perceived in series separated by many hundreds of milliseconds. Since the odorant perceived first is the main suppressor, knowledge of the order of perception of two odorants can allow prediction of interactions in mixtures. The present study investigated the temporal coding of ternary mixtures composed of carvone, coniferan and triethylamine, and citralva, lillial and triethylamine using a specially constructed air-dilution olfactometer. The results indicated that even though each of the components could be readily identified in ternary mixtures, it was very difficult to indicate which odor was perceived first, with chance scores being recorded. The same outcome occurred even when the 'slowest' odorant was delivered 600 ms after the 'fastest' to the nose. It is proposed that olfactory memory gives precedence to identification of the components of mixtures rather than to their order of perception when more than two odorants are in a mixture.

Fluorescent staining of kappa opioid receptors using naltrexamine derivatives and phycoerythrin

An immunofluorescent technique that is more sensitive than radioligand binding was developed in order to detect opioid receptors expressed on leukocytes. The current study was designed to optimize the method for fluorescently labeling kappa opioid receptors. For these experiments, the opioid antagonist naltrexamine was conjugated to either fluorescein (FITC-NTXamine) or biotin (biotin-NTXamine). One-step, two-step, and three-step protocols were compared to determine which procedure resulted in optimal staining of the kappa opioid receptor expressed on intact, unfixed R1E/TL8x.1.OUAr.1(R1EGO) cells, a thymoma known to express kappa opioid receptors. The one-step method involved incubating cells with FITC-NTXamine, and the fluorescein intensity was measured by flow cytometry. In the two-step method, cells were incubated with biotin-NTXamine, followed by extravidin-conjugated phycoerythrin, and the phycoerythrin fluorescence was measured. Finally, in the three-step protocol, cells were incubated with FITC-NTXamine, followed by biotin-conjugated anti-fluorescein IgG, then extravidin-phycoerythrin. The one-step protocol stained the cells, but the signal was not diminished in the presence of opioid competitors. The two-step approach did not stain cells significantly above background levels. Only the three-step approach yielded staining that was displaced by the kappa-selective antagonist nor-binaltorphimine. Thus, the addition of a secondary biotinylated antibody, resulting in the amplification of binding, which was detected using phycoerythrin as a fluorophore, was required to detect low levels of opioid receptor expression on leukocytes.

Mandibular enlargement: an unusual complication of a cervical cystic hygroma

A 13-year-old boy with a large cervical cystic hygroma, which extended into the floor of mouth, was referred for treatment of painful teeth and tongue. Clinically there was a large submandibular swelling, enlargement of the mandible and a Class III malocclusion. Intra-orally the tongue was enlarged and vesiculated. Gross caries was present in both mandibular permanent first molar teeth. Treatment comprised oral hygiene instruction, dietary advice, chlorohexidene mouth rinse, and removal of the carious teeth. At a later data, removal of the lesion and correction of the mandibular enlargement will be undertaken.

Juvenile systemic hyalinosis--a rare cause of gingival hypertrophy: a case report

A 5-year-old boy was referred because of gross gingival hypertrophy which caused severe feeding difficulties in addition to obvious aesthetic concern. The patient also suffered from frequent upper respiratory tract infections and diarrhoea. In addition, he had pigmentation on bony prominences of his hands, elbows, knees and ankles, cutaneous nodules behind his ear and granulomatous tissue adjacent to his nose. Excess gingival tissue was removed under general anaesthesia. Histological features suggested a diagnosis of juvenile hyaline fibromatosis, which is considered to represent the same underlying pathological condition as infantile systemic hyalinosis. It is suggested that systemic hyalinosis should be preceded by 'infantile' or 'juvenile' depending on the clinical presentation.

The influence of flavor and color on drink identification by children and adults

This study investigated how color and flavor influences drink identification by children and adults. The children ranged in age from 2 to 18 years of age. Each subject tasted four drinks that differed in color and flavor. Each drink had an atypical color-flavor pairing (e.g., brown-pineapple) or a typical pairing (e.g., brown-chocolate). After tasting each drink, the subject chose which of four flavor names identified the drink. For the atypical drinks, the selection of color-associated names (e.g., chocolate for a brown drink) decreased, and the selection of flavor-associated names increased with age from the preschoolers to the adults. For the typical drinks, the selection of the correct name was greater than 80% for all ages. These results suggest that drink identification becomes more influenced by flavor as children get older because of an increase in the ability of children to focus on flavor as their perceptual-attentional skills mature.

Hypersensitivity to an orthodontic bonding agent. A case report

A case report of a 14-year-old male who developed an allergic reaction shortly after the placement of Edgewise stainless steel orthodontic brackets with Unite, a composite bonding agent, is reported. Patch testing revealed that he was allergic to the set composite and the catalyst paste. The brackets were replaced by stainless steel orthodontic bands cemented with Poly F Zinc polycarboxylate cement which allowed treatment to progress without further incident.

Topographical differences in sweetness sensitivity in the peripheral gustatory system of adults and children

The sensitivity of localised areas of the anterior tongue of adults and 8-year-old males to the sweetener sucrose was determined, using a two-alternative forced choice psychophysical procedure. Stimulation of 12 areas by 0.2125 M sucrose or water, using a filter paper technique, indicated that the children were significantly more sensitive to the sweetener at eight of the areas. Counts of papillae at each of the 12 areas showed that there were similar numbers for adults and children at eight areas, whilst at three of the areas that exhibited a higher sensitivity to sucrose, children had significantly more papillae. Since 8-year-old males are less sensitive to sucrose when the stimulus is given as a whole-mouth stimulus [12], it is proposed that the children's gustatory system may be unable to integrate the information available at the tongue as efficiently as adults, or that the threshold and stimulus-response functions of receptor cells are different in the two groups.

Schwannoma of the anterior cranial fossa and paranasal sinuses

Only two cases of schwannomas involving the anterior cranial fossa and paranasal sinuses or nasal fossa have been reported previously. We describe a third case which involved all of these structures and also the left orbit.

Effects of alcohol on functional development of the auditory pathway in the brainstem of infants and chick embryos

The effects of alcohol on the development of neural function in the auditory pathway of the brainstem have been examined in human neonates and chick embryos. Auditory brainstem evoked responses were recorded in six infants of mothers for whom there was evidence of alcohol abuse during pregnancy. In four of the infants, evoked responses were abnormal, with poorly defined, inconsistent peaks. Neurophysiological and histological studies were done on chick embryos which received a single dose of alcohol early incubation. In most surviving embryos the neuroanatomical arrangement of the auditory nuclei in the brainstem was normal. However, Golgi impregnation revealed abnormalities in the length and structure of the dendrites in nucleus laminaris. Electrically evoked neuronal activity revealed abnormalities of synaptic function and the distribution of nerve terminals. The results indicate that in infants and chick embryos the functional development of the auditory pathway in the brainstem is disrupted by exposure to alcohol. Such early changes in this sensory pathway may contribute to the behavioural and intellectual handicaps associated with the fetal alcohol syndrome.

Death of motorneurons during the postnatal loss of polyneuronal innervation of rat muscles

A study was made of the decline in the number of motor neurons and axons of the brachial spinal cord of the rat during postnatal development. The injection of horseradish peroxidase (HRP) into the biceps muscle showed that it was innervated by motor neurons located in the dorsolateral position of the lateral motor column in segments C5 and C6; HRP injections into the triceps muscle showed that it was innervated by motor neurons located in the ventrolateral position of the lateral motor column in segments C7 and C8. There was no change in the position of these motor neuron pools between birth and maturity. However, there was a decline in the number of neurons in each pool during the postnatal period; over 35% of the neurons present at birth had disappeared by maturity. This loss of neurons was uniform throughout the rostrocaudal extent of each pool. It was accompanied by a similar percentage loss in the number of axons in a ventral root at the branchial level (C8). Electrophysiological measurements showed that the disappearance of motor neurons was accompanied by a loss in the polyneuronal innervation of synaptic sites in the biceps muscle. The possibility that a decrease in the number of neurons contributes to the loss of polyneuronal innervation is discussed.

The effect in vitro of high-density lipoprotein on hydrolysis of triacylglycerol by lipoprotein lipase

In an incubation system in vitro with fully activated Intralipid as substrate, rat high-density lipoprotein inhibits the hydrolysis of triacylglycerol by lipoprotein lipase from rat adipose tissue, but does not inhibit hydrolysis by the enzyme from bovine milk. The pattern of inhibition suggests that substrate and high-density lipoprotein may compete for association with rat adipose-tissue lipoprotein lipase.

"Anabolic" effects of methandienone in men undergoing athletic training

After failure to confirm an anabolic action of testosterone and its derivatives in rats, methandienone ('Dianabol', an "anabolic steroid" used by athletes) has been given to 11 athletic men during a course of weight-training, in a double-blind, crossover experiment. The dose of methandienone was 100 mg/day for 6 wk. Body weight and composition, muscular strength and performance, and indices of endocrine function were studied. Compared with the placebo period, on methandienone the subjects gained weight (mean 3-3 kg +/- 0-6 kg) and accumulated a disproportionately large amount of potassium (420+/-68 mmol); the increase in weight was confined to the lean part of the body, and the muscles increased in size. Strength and performance improved over each training period, but not significantly differently on drug and placebo. On the drug, plasma-cortisol concentration and urinary cortisol excretion increased, and plasma-testosterone decreased. Although the weight and body-composition changes may demonstrate an anabolic action of methandienone in man, they may alternatively have been caused by an increase in intracellular fluid, and the question of anabolic action therefore remains open.