Phenylalanine hydroxylase expression in liver of a fetus with phenylketonuria

The expression and activity of phenylalanine hydroxylase was studied in the liver of a fetus aborted after prenatal diagnosis of phenylketonuria. No phenylalanine hydroxylase enzymatic activity or immunoreactive protein was detectable in the PKU liver specimen, though both enzymatic activity and immunoreactive protein were detectable in control specimens of similar gestational age. Phenylalanine hydroxylase messenger RNA of normal size was present in the PKU fetal liver at normal abundance. These results confirm the genetic diagnosis of PKU in this fetus and indicate that the mutations in this fetus affect translation or stability of the phenylalanine hydroxylase protein.     

Electromyographic analysis of traditional and nontraditional abdominal exercises: implications for rehabilitation and training

BACKGROUND AND PURPOSE: Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent‐knee sit‐up. The purpose of this study was to test the effectiveness of traditional and nontraditional abdominal exercises in activating abdominal and extraneous musculature. SUBJECTS: Twenty‐one men and women who were healthy and between 23 and 43 years of age were recruited for this study. METHODS: Surface electromyography (EMG) was used to assess muscle activity from the upper and lower rectus abdominis, external and internal oblique, rectus femoris, latissimus dorsi, and lumbar paraspinal muscles while each exercise was performed. The EMG data were normalized to maximum voluntary muscle contractions. Differences in muscle activity were assessed by one‐way, repeated‐measures analysis of variance. RESULTS: Upper and lower rectus abdominis, internal oblique, and latissimus dorsi muscle EMG activity were highest for the Power Wheel (pike, knee‐up, and roll‐out), hanging knee‐up with straps, and reverse crunch inclined 30°. External oblique muscle EMG activity was highest for the Power Wheel (pike, knee‐up, and roll‐out) and hanging knee‐up with straps. Rectus femoris muscle EMG activity was highest for the Power Wheel (pike and knee‐up), reverse crunch inclined 30°, and bent‐knee sit‐up. Lumbar paraspinal muscle EMG activity was low and similar among exercises. DISCUSSION AND CONCLUSION: The Power Wheel (pike, knee‐up, and roll‐out), hanging knee‐up with straps, and reverse crunch inclined 30° not only were the most effective exercises in activating abdominal musculature but also were the most effective in activating extraneous musculature. The relatively high rectus femoris muscle activity obtained with the Power Wheel (pike and knee‐up), reverse crunch inclined 30°, and bent‐knee sit‐up may be problematic for some people with low back problems.     

Ultrastructural evidence for remodelling in a central noradrenergic pathway following electrolytic lesioning

Electrolytic lesions were carried out in the medial hypothalamus of adult rats to study remodelling responses in a central noradrenergic pathway, the medial forebrain bundle. Four days, two weeks, 4 weeks and 8 weeks post-lesion, the animals were perfused and processed for correlated fluorescence microscopic (FM) and electron microscopic (EM) study. FM evaluation 4 days post-lesion showed that, compared with control preparations, catecholaminergic fibers became thick, distorted and intensely fluorescent. With increasing survival times the caliber of these fibers became finer and fluorescence intensity was gradually diminished. Some of the small blood vessels in the vicinity of the lesion acquired an intense perivascular fluorescence. Electron microscopic examination of the lesion site 4 days post-lesion disclosed many degenerating axons and increased extracellular space. No increased extracellular space was discerned by 8 weeks post-lesion. After all survival periods greatly enlarged axonal profiles were seen, and these resembled 'growth cones' described in earlier tissue culture, developmental and peripheral nervous system studies.     

A novel synthetic route to 11-deoxyanthracycline AB synthons

An efficient synthetic method for 11-deoxyanthracycline AB synthons is described. A versatile key intermediate vinyl bromide3 was prepared from 5-methoxy-1-tetralone in three steps, and then was converted to the allylic alcohols4 and8 which, in tum, fumished highly fuctionalized AB synthons7 and12, respectively, via sequential epoxidation-reduction-protection processes.     

Biotransformation of dehydroparadols byAspergillus niger

To prove uniqueness of allylic alcohol formation from α,β-unsaturated ketones by mammal enzymes, a metabolic pattern of dehydroparadols, non-pungent synthetic analogs of shogaol byAspergillus niger was examined. Two biotransformation products of a dehydroparadol, 1-(4-hydroxy-3-methoxyphenyl)-non-1-en-3-one were accumulated in the culture broth ofA. niger. They were characterized as 1-(4-hydroxy-3-methoxyphenyl)-non-1-en-9-ol-3-one and 1-(4-hydroxy-3-methoxyphenyl)-nonan-9-ol-3-one by UV, NMR and mass spectroscopic analyses. Accumulation of allylic alcohol metabolites was not observed.     

Effects of redirecting the vagosympathetic trunk into the hypothalamus

The cat vagosympathetic trunk was redirected into the hypothalamus to study peripheral and central nervous system interrelationships and their possible effects on the regenerative responses. Electron microscopy permitted detailed scrutiny of the morphologic characteristics of degeneration, growth, and other cytological changes. Three months after insertion into the hypothalamus, the vasgosympathetic fibers appeared healthy and many axonal growth cones and incompletely ensheathed neurites were present—features characteristic of regenerating axons. Signs of active growth were relatively sparse in the surrounding central nervous system tissue but central axonal and presumed dendritic growth cones were observed. These were more numerous after the peripheral nerve had been cut and allowed to undergo degeneration prior to insertion into the central nervous system. Although there was considerable intermingling of peripheral and central elemets in the boundary zone between them, evidence of synaptic union between the peripheral and central neurons was not observed.     

Fluorescence immunohistochemistry and confocal scanning laser microscopy: a protocol for studies of joint innervation

We have developed a reliable technique for labeling and examining neural structures in soft tissues associated with articular joints and have tested it in human wrist joints under various specimen-related conditions. The labeling protocol employs an immunohistochemical process with a panneuronal marker (PGP 9.5) as the primary antibody and Alexa Fluor 488 as the fluorescing secondary antibody. Imaging was done using a confocal laser scanning microscope, which produced exceptionally detailed three-dimensional images of nerve endings and transiting nerve fibers from thick sections of wrist joint ligaments obtained from human cadavers. The protocol provided a practical postmortem window for specimen acquisition and processing without significant apparent worsening of image quality. The images produced are resistant to fading with repeated exposure to a fluorescent light source, which gives many opportunities for observation. Background staining is minimal, producing high contrast labeling of target tissues, which, in turn, enhances image analysis.     

Learning deficits and brain monoamines in rats with congenital hyperbilirubinemia

At 28 days of age, rats with congenital hyperbilirubinemia (homozygous Gunn strain) were submitted to an active learning task (two-way shuttlebox avoidance) and a passive learning task (step-down avoidance) and the results compared with controls (heterozygous littermates). Jump thresholds to painful footshock were used as measures of pain sensitivity. After testing, the concentration of dopamine and norepinephrine was measured in eight brain regions. The jaundiced Gunn rat demonstrated significant learning retardation on both avoidance tasks compared with their controls. Because jump thresholds to shock were similar in hyperbilirubinemic animals and their controls, these differences in learning performance could not be attributed to differences in sensitivity to footshock. Norepinephrine concentrations in hypothalamus and hippocampus were elevated in jaundiced rats compared with controls. In jaundiced rats, dopamine concentrations in striatum and pons-medulla were diminished. Cerebella in jaundiced rats were significantly smaller, and total content of both dopamine and norepinephrine significantly lower in jaundiced rats compared with controls. Learning deficits in young jaundiced Gunn rats may be associated with the changes in brain catecholamine concentrations found in these animals. To determine whether or not any recovery from hyperbilirubinemia occurs, similar behavioral and biochemical testing could be applied to homozygous Gunn rats at different stages in development.     

Catecholamine inputs to the nucleus tractus solitarius

The projections of brainstem catecholaminergic (CA) cell groups to the rat nucleus tractus solitarius (NTS) were examined using 6-hydroxydopamine (6-OHDA) injections and glass microknife cuts. 6-OHDA (4 micrograms) was injected into the intermediate NTS, and this resulted in depletion of CA fluorescent varicosities from the NTS at this rostrocaudal level, except for varicosities along the periventricular edge of the NTS. In addition, a band of swollen fluorescent axons extended between the CA A1 cell group of the ventrolateral medulla and the lateral NTS. Microknife cuts were used to interrupt the projections of the CA A1 and A2 cell groups (located in the caudal NTS) and tissues were examined for changes in CA varicosity density within the intermediate NTS. Following transverse knife cuts of the intermediate NTS, rostral to the A2 cell group, fluorescent varicosities rostral to the cut virtually disappeared, and the fluorescence intensity of the ipsilateral A2 neurons caudal to the cut was increased. These cuts also eliminated the 6-OHDA-resistant varicosities along the periventricular NTS. After microknife cuts lateral to the intermediate NTS, the fluorescent varicosity density in the NTS was unchanged. These results indicate that the major CA projection to the NTS arises from the ipsilateral A2 cell group. The 6-OHDA-resistant varicosities arising from neurons caudal to the knife cut probably arise from the adrenergic C2 cell group.