Effect of Preservative Pretreatment on the Biological Durability of Corn Straw Fiber/HDPE Composites.

The effects of alkaline copper quaternary (ACQ) and zinc borate (ZB) on the resistance of corn stalk fiber (CSF)-reinforced high-density polyethylene (HDPE) composites to biodegradation were examined. Both biocides could inhibit termites, mold fungi, and wood-decay fungi, even at high CSF formulations (i.e., 60%). Additionally, ACQ enhanced the resistance of the composite materials to certain biotic stresses better than ZB. The CSF/HDPE composites treated with ACQ at the 3.0% level exhibited a superior performance against termites, white rot fungi, and brown rot fungi. ACQ treatment at the 1% level was optimal for inhibiting soft rot fungi. Furthermore, mold growth was not observed on ACQ-treated CSF/HDPE samples. The untreated CSF/HDPE composites were more susceptible to mold infections and decay than the untreated poplar/HDPE composites, likely because of an incomplete removal of the pith. The chemical features of the corn stalk may also have influenced these differences, but this possibility will need to be explored in future investigations. Furthermore, the CSF component of CSF/HDPE composites is highly susceptible to fungal attacks, with the soft rot fungus inducing the largest mass losses, followed by the white rot fungus, and then the brown rot fungus.

Presence of octopamine in firefly photomotor neurons.

Various tissues involved in producing luminescence in larval fireflies (Photuris versicolor) were examined for the presence of octopamine. These tissues included the terminal abdominal ganglion (A8) which innervates the paired lantern organs, the cell bodies of the photomotor neurons and the isolated larval lanterns. A previous study has identified the 4 motoneurons arising from A8 which bilaterally innervate the paired larval lanterns through symmetrical axons existing both sides of the ganglion. Individual photomotor neuron somata were isolated, pooled and found to contain about 0.03 pmol/soma giving an effective concentration of 2.8 mM octopamine. Significant amounts of octopamine were also found within the peripheral effector tissue. The presence of octopamine throughout the luminescence-producing pathway further supports the hypothesis that octopamine serves a neurotransmitter function in firefly bioluminescence. In this system, it appears that octopamine serves a more direct role as a neurotransmitter that that postulated for its modulatory and hormonal functions in other arthropod systems. Furthermore, the bioluminescent response of the larval firefly lantern provides a useful dynamic system to study the physiology, pharmacology and biochemistry of octopaminergic transmission.

Chromosomal polymorphisms of 1, 9, 16, and Y in 4 major ethnic groups: a large prenatal study.

Using trypsin Giemsa banding (GTG), major polymorphisms of the constitutive heterochromatin regions of chromosome 1, 9, 16, and Y were recorded in a New York City population. Polymorphisms were recorded from amniotic fluid specimens received from 6,250 patients from 4 major population groups, ie, White (European)-2,334 cases, American Black-1,795 cases, Hispanic descent-1,737 cases, and Asian (Oriental and Indian)-384 cases. The major chromosomal polymorphisms were classified as follows: obvious pericentric inversion of the constitutive heterochromatin of the long arm of the chromosome (inv qh); significantly enlarged heterochromatic region of the long arm (qh + is greater than, or equal to, twice the size of the short arm of chromosome 16 [16p]); very small or deficient heterochromatic region in the long arm (qh-); large Y (Yq + greater than size of chromosome 18), small Y (Yq- less than size of a G-group chromosome), and pericentric inversion of Y. Our prenatal study confirmed that the incidence of specific chromosomal variants is different in each population group. The most striking examples of this are the pericentric inversion of chromosome 9 and the different polymorphisms of the Y chromosome. The incidence of inv (9) is highest in the Black population (3.57%); slightly above average in Hispanics (2.42%); and relatively low in Whites (0.73%) and Asians (0.26%). The Y appears to be more variable in Asian (3.37%) and Hispanic (1.82%) than in White or Black groups. The 9qh+ is seen more frequently than 1qh+, or 16qh+. Inv (1), 9qh-, and 16qh- are rare. There were no cases of either 1qh- or inv (16).(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital adrenal hyperplasia: update on prenatal diagnosis and treatment.

The diagnostic term congenital adrenal hyperplasia (CAH) applies to a family of inherited disorders of steroidogenesis caused by an abnormality in one of the five enzymatic steps necessary in the conversion of cholesterol to cortisol. The enzyme defects are translated as autosomal recessive traits, with the enzyme deficient in more than 90% of CAH cases being 21-hydroxylase. In the classical forms of CAH (simple virilizing and salt wasting), owing to 21-hydroxylase deficiency (21-OHD), androgen excess causes external genital ambiguity in newborn females and progressive postnatal virilization in males and females. Non-classical 21-OHD (NC21OHD) refers to the condition in which partial deficiencies of 21-hydroxylation produce less extreme hyperandrogenemia and milder symptoms. Females do not demonstrate genital ambiguity at birth. The gene for adrenal 21-hydroxylase, CYP21, is located on chromosome 6p in the area of HLA genes. Specific mutations may be correlated with a given degree of enzymatic compromise and the clinical form of 21-OHD. NC21OHD patients are predicted to have mild mutations on both alleles or one severe and one mild mutation of the 21-OH locus (compound heterozygote). In most cases the mutation groups represent one diagnosis (e.g., Del/Del with SW CAH), however we have found several non-correlations of genotype to phenotype. Non-classical and classical patients were found within the same mutation group. Phenotypic variability within each mutation group has important implications for prenatal diagnosis and treatment. Prenatal treatment of 21-OHD with dexamethasone has been utilized for a decade. An algorithm has been developed for prenatal diagnosis and treatment, which, when followed closely, has been safe for both the mother and the fetus, and has been effective in preventing ambiguous genitalia in the affected female newborn. This is an instance of an inborn metabolic error successfully treated prenatally. Since 1986, prenatal diagnosis and treatment of congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OHD) has been carried out in 403 pregnancies in The New York Hospital Cornell Medical Center. In 280, diagnoses were made by amniocentesis, while 123 were diagnosed using chorionic villus sampling. Of the 403 pregnancies evaluated, 84 babies were affected with classical 21-OHD. Of these, 52 were females, 36 of whom were treated prenatally with dexamethasone. Dexamethasone administered at or before 10 weeks of gestation (23 affected female fetuses) was effective in reducing virilization. Thirteen cases had affected female sibs (Prader stages 1-4); 6 of these fetuses were born with entirely normal female genitalia, while 6 were significantly less virilized (Prader stages 1-2) than their sibs, and one was Prader stage 3. Eight newborns had male sibs: 4 were born with normal genitalia, 3 were Prader stages 1-2, and 3 were born Prader stages 3-4. No significant or enduring side effects were noted in either the mothers or the fetuses, indicating that dexamethasone treatment is safe. Prenatally treated newborns did not differ in weight, length, or head circumference from untreated, unaffected newborns. Based on our experience, proper prenatal diagnosis and treatment of 21-OHD is effective in significantly reducing or eliminating virilization in the newborn female. This spares the affected female the consequences of genital ambiguity of genital surgery, sex misassignment, and gender confusion.

A comparative approach to the behavior called "learned helplessness'.

The phenomenon of 'learned helplessness' is seen broadly across the animal kingdom. The basic characteristics of this behavior are similar in intact mammals, lower vertebrates and invertebrates. In fact, the basic characteristics even are seen in an isolated thoracic ganglion of an insect. The brain is evidently not essential either in mammals or in invertebrates for demonstrating this behavior. A neutral terminology is suggested that allows for investigation of this behavior and its underlying mechanisms in both intact and surgically simplified preparations of both vertebrates and invertebrates. Thus, its phylogeny can be investigated. In addition, simpler systems such as the insect ventral nerve cord with its large neurons and its ease of pharmacological manipulation may have important contributions to make to understanding the neuropharmacology underlying it. The ubiquity of the phenomenon in different phyla suggests that while in the laboratory it may appear maladaptive, this may not necessarily be the case in a natural ecological context. Because of increasing governmental regulations in both Europe and the US on mammalian studies involving shock and distress, such as that associated with 'learned helplessness', it may be prudent to consider other systems that may offer insight into its underlying mechanisms.

Leg position learning in the cockroach nerve cord using an analog technique.

The ultimate goal of this research is to correlate neural activity with leg behavior during learning. Contrary to previous studies of shock avoidance learning in the headless cockroach, in which an all-or-none method of recording was used, we have adopted a direct analog recording of leg position to measure learning in the prothoracic ganglion. This method provides a sensitive and continuous record of leg movement that can be correlated with the interactions of individual neurons that may be involved in such learning. Of the 10 prothoracic legs trained to flex to avoid shock, eight escaped shock by flexion within a maximum of 13 min and seven showed savings when retested. Only four of eight prothoracic legs trained to extend showed avoidance learning and all four showed savings. Electrical stimulation of nerves 3,4,5, and 6 innervating the prothoracic leg revealed which nerves were instrumental in the flexion and extension responses.

An analog technique for recording leg position learning in the cockroach.

Past studies of shock avoidance learning in the cockroach have used an all-or-none method of recording leg position. Leg position was recorded indirectly in terms of the number of shocks the leg initiated. The measure of learning was the decrease in the number of times the leg initiated shock. An analog procedure is described that allows the pattern of leg behavior change to be assessed directly. Thus, the time course and relative magnitude of leg flexions and extensions prior to, during, and following shock can be studied. It will be possible to record peripheral motor nerve activity simultaneously with the behavior and to examine the excitatory and inhibitory interactions of individual neurons that may be involved in such learning.

A ganglionic model of "learned helplessness".

The phenomenon known as "learned helplessness" (LH) is seen broadly across the animal kingdom. Some of the basic characteristics of this behavior are: failure to escape shock when it is possible to do so following non-escapable shock; reversion to non-escape behavior even after successful escape; if the animal is given escape/avoidance training prior to being given inescapable shocks, the latter will not interfere with its ability to later show normal escape/avoidance behavior (generally described as an immunization effect); following inescapable shock training the animals often become "passive and still" when confronted with an inescapable shock. These behaviors are seen in intact mammals, lower vertebrates, and invertebrates. In fact, the basic characteristics are even seen in a spinal rat and, with the exception of one characteristic not yet examined, in an isolated thoracic ganglion of an insect. The brain is evidently not essential either in mammals or in invertebrates for demonstrating this behavior. Not only can an insect ganglion show the behavioral characteristics of LH, but the neural information underlying the phenomenon of LH can be shown to transfer from one ganglion innervating one pair of legs to another ganglion innervating a different pair of legs. Thus, how CNS information underlying LH is coded and transferred from one site to another within the CNS can be examined in such a system. The LH model has provided valuable insights into the physiology of depression. This model suggests that human depression is caused by one's lack of control over traumatic events. It is supported by a number of parallels between depression and LH behavior. Tricyclic antidepressants, MAO inhibitors, and ECT, which are effective in treating depression, also can prevent and reverse LH in mammals. It would be important to find out if they are also effective in invertebrate models. The fact that the characteristics of the behavior called LH are seen in invertebrates such as slugs, cockroaches, and locusts provokes other intriguing questions about the presence of cognition at these phylogenetic levels, as well as what animal or preparation constitutes an appropriate model for human depression.

Development of improved high-performance liquid chromatography conditions for nonisotopic detection of isoaspartic acid to determine the extent of protein deamidation.

A rapid and accurate ion-pairing reversed-phase high-performance liquid chromatography (IP-RP-HPLC) procedure has been developed for nonisotopic detection of isoaspartic acid residues in protein or peptides resulting from deamidation of asparagine residues. The IP-RP-HPLC procedure specifically detects and quantifies S-adenosylhomocysteine (SAH). SAH is a by-product of the reaction between protein isoaspartyl methyltransferase (PIMT), S-adenosylmethionine (SAM), and isoaspartic acid residues. The HPLC conditions described in this paper have been demonstrated to offer significantly better reproducibility compared to earlier studies. The HPLC method allows determination of the extent of protein deamidation without the use of radioisotopes and therefore offers significant advantages for biopharmaceutical development laboratories.

Ionic basis of axonal excitability in an extreme euryhaline osmoconformer, the serpulid worm Mercierella enigmatica (Fauvel).

Despite the extreme fluctuations in blood concentration experienced by this marine osmoconformer, essentially 'conventional' ionic mechanisms are involved in conduction by the giant axons in isosmotic conditions. The resting axonal membrane approximates to an ideal potassium electrode, with a 58-8 mV slope for decade change in [K+]O above 10 mM. The action potential overshoot shows a 55-8 mV decline with decade reduction in [Na+]O and the action potentials are blocked by tetrodotoxin at around 5 X 10(-7) M. The rising phase and overshoot of the action potential remain constant at potassium concentrations up to the relatively high level of 30 mM found in the blood, indicating an unusual absence of sodium inactivation over a wide range of resting potentials. Relatively rapid, symmetrical movement of potassium ions between the bathing medium and the axon surface is deduced from the potential changes induced by alterations in [K+]O. Outward movement of sodium ions (t0-5 = 33-5 s) occurs at a similar rate to that of potassium, but inward movement of Na+ is relatively slow and complex. It is concluded that the ability of axons to function in dilute media must involve specific adaptations to osmotic and ionic stress.

Octopamine: presence in firefly lantern suggests a transmitter role.

The lantern of the adult firefly is innervated by a nerve supply with endings similar to other known monoaminergic nerves. However, catecholamines could not be detected in the nerve endings and noradrenaline and adrenaline were relatively weak agonists in eliciting a flash of light when applied to the lantern in vitro. Firefly lanterns were assayed for octopamine using a sensitive, specific enzymatic assay in which octopamine is enzymatically converted to 3H-synephrine and quantitated by liquid scintillation counting. The presence of substantial amounts (125 ng/g tissue) of octopamine was demonstrated and confirmed by thin layer chromatography. On the basis of this and earlier work, it is suggested that the nerves to the firefly lantern are octopaminergic.