Deep peroneal sensory nerve. Standardization in nerve conduction study

Ankle or foot pain may be due to various clinical conditions. Injury or entrapment of the deep peroneal sensory nerve is part of the differential diagnosis; however, no technique studying the deep peroneal sensory conduction velocity has been described. We describe a technique that is simple and reproducible with averaging. We electrophysiologically studied the deep peroneal sensory nerve in 40 neurologically healthy adult subjects. The latency to onset of the sensory action potential was 2.9 +/- 0.4 ms (range = 2.1-3.6 ms). The latency to the peak of the sensory action potential was 3.6 +/- 0.4 ms (range = 2.7-4.2 ms). The conduction velocity was 42 +/- 5 m/s (range = 33-53 m/s). The amplitude was 3.4 +/- 1.2 microV (range = 1.6-6.6 microV). We conclude that the deep peroneal sensory nerve is readily accessible for electrophysiologic evaluation. It may be of value in diagnosing deep peroneal nerve pathology.

New potent topical anti-inflammatory steroids with reduced side effects: derivatives of steroid-16-carboxy esters

Therapeutic use of anti-inflammatory steroids is limited due to their potential suppressive effects on pituitary-adrenal function and the immune system. Based on the antedrug concept, a new class of potent locally active compounds with reduced risk of side effects has been synthesized from prednisolone by introducing a metabolically labile methoxycarbonyl substituent at C-16. Results of topical application of the lead compound, methyl 11 beta,17 alpha,21-trihydroxy-3,20-dioxo-pregna-1,4-diene-16 alpha-carboxylate (P16CM;1), showed that it was 14 times more potent than prednisolone and that it had a greatly reduced tendency to cause systemic side effects. In the present investigations, we have demonstrated that chemical modifications such as 17- and/or 21-esterifications and 17,21-acetonidation of 1 further enhance topical activity in the croton oil ear edema model in rats. Following multiple topical ID50 applications of 1 or its derivatives, no thymolysis was noted. In the carrageenan-soaked sponge model of acute inflammation, all derivatives were potent inhibitors of leukocyte migration, generation of PGE2, and release of elastase. Taken together, these results indicate that esterification or acetonidation of hydroxyl groups at the 17 and/or 21 position, in combination with a labile C-16 methoxycarbonyl group, increases topical activity without concomitantly increasing the risk of side effects.

Neuronal properties and trophic activities of immortalized hippocampal cells from embryonic and young adult mice

The hippocampal formation elaborates trophic factors such as nerve growth factor (NGF) to support the cholinergic innervation it receives from the septal region. To further study the trophic interactions of this pathway, hippocampal cells from embryonic day 18 and postnatal day 21 mice were immortalized via somatic cell fusion to N18TG2 neuroblastoma cells. The hippocampal cell lines exhibit morphological and cytoskeletal features which are typical of their neuronal parents but which are not expressed by the neuroblastoma parent. When differentiated with retinoic acid, the hippocampal cell lines exhibit electrophysiological features similar to cultured hippocampal neurons. Many of the lines constitutively express high levels of NGF, and at least one cell line exerts a non-NGF trophic effect on the expression of choline acetyltransferase by septal neurons in vitro. These cell lines are potentially useful for investigating the neurochemical and excitable properties of hippocampal neurons and identifying novel trophic activities that promote the development and maintenance of the septohippocampal pathway.

Needle electrode insertion into tibialis posterior. A new approach

The tibialis posterior can be a valuable muscle in the electrodiagnostic evaluation of the sacral plexus, lumbosacral roots, lower extremity neuropathies and tibial nerve lesions. It may be under utilized, however, because it is generally considered to be inaccessible to needle examination. The purpose of this study was to compare the widely recommended posterior approach to this muscle to an anterior approach that we define. In six cadaver legs, the safe access to this muscle via the anterior approach was 16.8 +/- 5 mm by contrast to 9.5 +/- 2 mm by the posterior approach. We conclude that the anterior approach to needle electromyography of the tibialis posterior muscle is easier, safer and deserves more widespread practice.

Development and characterization of clonal cell lines derived from septal cholinergic neurons

Studies employing primary cells to determine the molecular basis of neuronal development and selective synaptogenesis in the central nervous system are limited by cellular heterogeneity. Clonal hybrid cell lines derived from a particular region of brain, which express differentiated characteristics typical of the cells of origin, offer a potentially powerful alternative approach. We previously demonstrated the feasibility of deriving such cell lines from septal cholinergic cells. We now delineate the methods employed, and describe the development of additional cholinergic cell lines expressing neuronal and cholinergic features from later developmental stages. One cell line has been studied in detail and found to form neurites, express choline acetyltransferase (ChAT) and neurofilament protein (NFP), and display typical neuronal ultrastructural characteristics, including puncta adherens, neuritic varicosities, vesicles, and growth cones.

Kinetic analysis of duck epsilon-crystallin, a lens structural protein with lactate dehydrogenase activity

Biochemical characterization and kinetic analysis of epsilon-crystallin from the lenses of common ducks were undertaken to elucidate the enzyme mechanism of this unique crystallin with lactate dehydrogenase (LDH) activity. Despite the structural similarities between epsilon-crystallin and chicken heart LDH, differences in charge and kinetic properties were revealed by isoenzyme electrophoresis and kinetic studies. Bi-substrate kinetic analysis examined by initial-velocity and product-inhibition studies suggested a compulsory ordered Bi Bi sequential mechanism with NADH as the leading substrate followed by pyruvate. The products were released in the order L-lactate and NAD+. The catalysed reaction is shown to have a higher rate in the formation of L-lactate and NAD+. Substrate inhibition was observed at high concentrations of pyruvate and L-lactate for the forward and reverse reactions respectively. The substrate inhibition was presumably due to the formation of epsilon-crystallin-NAD(+)-pyruvate or epsilon-crystallin-NADH-L-lactate abortive ternary complexes, as suggested by the product-inhibition studies. The significance and the interrelationship of duck epsilon-crystallin with other well-known LDHs are discussed with special regard to its role as a structural protein with some enzymic function in lens metabolism.

Immortalized young adult neurons from the septal region: generation and characterization

Studies of the development of the central nervous system would be greatly facilitated by the ability to immortalize neuronal tissue from a broad range of ages. We have previously used somatic cell fusion techniques to generate neuronal cell lines from embryonic mice. To immortalize older neuronal cells, a cell isolation technique was developed to obtain viable septal cells from postnatal day 21 mice. The septal cells were fused to N18TG2 neuroblastoma cells and then cultured in selective medium to isolate septum x neuroblastoma cell lines. The hybrid nature of the lines was verified by chromosome analysis and electrophoretic analysis of glucosephosphate isomerase isozymes. The lines express phenotypes typical of differentiated septal neurons. Many lines morphologically resemble neurons and express the high molecular weight neurofilament protein. Several lines express high levels of choline acetyltransferase activity; others synthesize nerve growth factor. These results demonstrate that young adult neuronal tissue can be immortalized and that hybrid cells express properties of the neuronal parent.

Regulation of the hydrolytic and transfer activities of gamma-glutamyl transpeptidase

The activity of gamma-glutamyl transpeptidase was inhibited and stimulated by hippurate with and without acceptor molecules, respectively. Substrate activation was observed when acceptor molecules was not present but the activation was disappeared by the addition of hippurate. When glutamine was absent the inhibition degree of hippurate at pH 8.0 was greater than at pH 7.0, whereas in the presence of both hippurate and glutamine the results were opposed. These show a possibility that glutaminase is activated by hippurate under the condition of physiological pH. The activation of glutaminase by hippurate was also confirmed directly. The inhibition degree of transfer activity by glutamine was increased along the increase of acceptor concentration only in the presence of hippurate. Gamma-Glu-Phe-Gly satisfying prerequisites for donors doesn't act as a substrate, which shows that L-gamma-glutamyl-p-nitroanilide itself hardly acts as an acceptor. This contradicts to an idea that substrate activation caused by autotranspeptidation. The change of apparent Km and Vmax according to the change of pH in the presence of hippurate was different from that in the presence of acceptors. This shows a possibility that the active site on small subunit is inhibited and the latent active site in large subunit is exposed by the interaction of hippurate to the enzyme.

Pharmacokinetics of prednisolone and its local anti-inflammatory steroid-21-oate ester derivatives. In vitro and in vivo comparative study

A new class of local anti-inflammatory steroid-21-oate esters synthesized by modifying the ketol side chain of prednisolone was found to exhibit minimal systemic side effects such as pituitary-adrenal suppression. It has been hypothesized that the absence of the systemic toxicities of these steroids is due to the rapid hydrolysis of the carboxylate ester group to inactive and readily excretable acid metabolites. The pharmacokinetics of prednisolone and its two ester derivatives, methyl 20 alpha- and 20 beta-dihydroprednisolonate (P4 alpha and P4 beta), were studied in rats following im administration of doses ranging from 0.5 to 10 mg/kg. The absorption of each of the three compounds was rapid, as the peak concentration was attained within 20 min after injection. The elimination half-lives of P4 alpha, P4 beta, and prednisolone were independent of dose and were 1.12, 0.28, and 0.53 hr at 10 mg/kg doses, respectively. The AUCs of P4 alpha, P4 beta, and prednisolone following a 10 mg/kg dose were 7678, 242, and 3037 ng/ml.hr, respectively. The pharmacokinetics of the P4 alpha were linear as the AUC increased proportionally with dose. An in vitro study showed that P4 beta was approximately 100% hydrolyzed within 1 hr in plasma at 37 degrees C, whereas P4 alpha was about 30%. However, a negligible disappearance of prednisolone occurred in vitro over a period of more than 2 days. These results suggest that the minimal systemic side effects of these new steroids may be ascribed to the differences in their pharmacokinetic profiles and metabolism from those of prednisolone.

[Intraocular lens implantation at Kaohsiung Medical College]

Between March 1984 and December 1987, 993 cataractous eyes in 884 patients (462 males, 422 females) were operated on using intraocular lens implantation at the Kaohsiung Medical College Hospital. The age of the patients ranged from half year to 93 years, with an average of 61.9 years. Primary lens implantation was performed in 98.4% of the cases, secondary implantation in 1.6% of the cases. There were 6 cases were done by using the triple procedure (combined keratoplasty with cataract extraction and intraocular lens implantation). Among these 742 eyes followed-up for from one to 43 months, final vision could be corrected to 6/12 or better in 63.5% of the cases. While 64.4% of the cases of post-operation cylinder were less than 2 diopters, the final refraction showed that the spherical equivalent diopters were within 2 diopters in 61.7% of the cases. Complications in the anterior chamber lens group included pupillary changes (21.2%), pseudophakic bullous keratopathy or decompensation (13.5%), lens subluxation or dislocation (13.5%) and cystoid macular edema (5.8%). Complications in the posterior chamber lens group included pupillary changes (16.2%), posterior capsular thickening (3.2%), anterior or posterior synechiae (2.7%) and lens subluxation or dislocation (2.8%).

Large mass-like pulmonary cryptococcosis: report of 2 cases

Pulmonary cryptococcosis, a less common fungal infection, frequently reveals nodular lesions (single or multiple) and patchy infiltrations (alveolar or interstitial) on chest X rays. A large mass-like pattern is less common. Here we report 2 cases of pulmonary cryptococcosis with negative bronchoscopic findings. One patient received a right lower lobectomy under the impression of malignancy; the other received a transthoracic needle aspiration, and numerous cryptococci were found by India ink preparation. Thus, pulmonary cryptococcosis should be included in the differential diagnosis of a mass lesion. A brief review of the literature is also included about diagnostic approach and management of pulmonary cryptococcosis.

Erythrocytes as barriers for drug elimination in the isolated rat liver. II. Propranolol

The potential of erythrocytes (RBC) to serve as "barriers" of hepatic elimination of propranolol, a drug with rapid equilibration in blood, was studied in rats under two conditions: (I) the drug was preequilibrated in blood before infusion into the liver, and (II) the drug was directly infused into the liver. The mean fractions of dose escaping elimination during each pass under conditions I and II were 0.0561 +/- 0.040 and 0.0290 +/- 0.024, respectively (P less than 0.02). Contrary to the early study on doxorubicin, most drug molecules in RBC were found to be available for elimination. Implications of the present findings in the prediction of hepatic first-pass effect after oral administration, on the basis of intravenous data, are discussed. Marked underestimation of oral bioavailability of propranolol in humans is consistent with the RBC "barrier" effect hypothesis.

Synthesis and pharmacological evaluation of conjugates of prednisolone and non-steroidal anti-inflammatory agents

Esters of prednisolone with ibuprofen and indomethacin were prepared by coupling the 21-hydroxy moiety of the glucocorticoid to the carboxylic group of the non-steroidal anti-inflammatory agents. The local and systemic anti-inflammatory activities of the conjugates were evaluated using the cotton pellet granuloma bioassay and their topical activity evaluated by the croton oil-induced ear edema assay, in male Sprague-Dawley rats. The results indicate that these conjugates possess greater local and topical anti-inflammatory activity than prednisolone. In the subacute ear edema bioassay, the conjugates displayed no discernible untoward systemic effects, unlike prednisolone and prednisolone acetate, which elicited significant adverse systemic effects, at equipotent doses. These findings suggest that the chemical coupling of prednisolone and non-steroidal anti-inflammatory agents produced compounds with enhanced anti-inflammatory potencies and reduced systemic toxicities, particularly when administered topically.

Erythrocytes as barriers for drug elimination in the isolated rat liver. I. Doxorubicin

The effect of doxorubicin (Dx) equilibration between plasma and erythrocytes (RBC), prior to entering the liver, on hepatic elimination was evaluated under two conditions: (I) the drug being first equilibrated for 30 min in the perfusate (containing 27% human RBC) before infusion into the liver and (II) the drug being directly infused into the liver. Mean (N = 6) steady-state hepatic extraction ratios (E) under conditions I and II were 0.286 +/- 0.131 (SD) and 0.592 +/- 0.147, respectively. The marked difference in E was attributed mainly to the initial difference in plasma/RBC Dx distribution ratio of the inlet blood, the slow efflux of Dx from RBC into plasma under condition I, and the slow influx of Dx from plasma to RBC under condition II. The results indicate that most Dx molecules in RBC are not available for elimination. Drug equilibration between plasma and RBC may therefore represent an important factor in hepatic first-pass metabolism.

Identification of a new transcriptional initiation site and the corresponding functional gene 2b in the murine coronavirus RNA genome

We have previously shown that some strains of the murine coronavirus mouse hepatitis virus (MHV) synthesize an additional mRNA species (mRNA 2b, previously called mRNA 2a) with a size intermediate between that of mRNAs 2 and 3, suggesting the presence of an optional transcriptional initiation site. This transcriptional start is dependent on the leader sequence of the virus strains. To study the mechanism of coronavirus transcriptional regulation, we have cloned and sequenced the region of the viral genome corresponding to the 5' unique coding region of mRNA 2 of the JHM strain of MHV. In addition to the open reading frame (ORF) predicted to encode the viral nonstructural protein p30, a second complete ORF, with the potential to encode a 439-amino-acid polypeptide, was discovered. The transcriptional initiation sites of both mRNA 2a (formerly called mRNA 2) and mRNA 2b were determined by primer extension studies and RNA sequencing. The data indicated that transcription of mRNA 2a initiated at a site, UCUAUAC, that resembled the consensus intergenic sequence. In contrast, the start signal of the optional mRNA 2b, UAAUAAAC, deviated from the consensus sequence. mRNA 2b is a functional mRNA, as shown by in vitro translation studies of mRNA and ORF 2b and by the detection of an additional viral structural protein, gp65, in the JHM strain that synthesized this mRNA. Although the A59 strain of MHV was found to retain ORF 2b, it lacked the correct transcriptional and translational start signals for this gene. This study has therefore identified an optional gene product for murine coronaviruses and provided insights into the mechanism of regulation of MHV RNA transcription.

Effect of change in blood flow on hemodialysis clearance studied by a simple unified organ clearance approach

The applicability of a simple noncompartmental organ clearance approach was extended to evaluate the effect of change in blood flow (Q) on hemodialysis clearance (CL) using patient data reported in the literature. Hemodialysis blood or plasma clearance data of vitamin B12, urea, creatinine and uric acid were fitted into the equation, CL = HQ/(Q + H), where H is the apparent intrinsic hemodialysis clearance for total (bound and unbound) compound. The Q values varied up to 16-fold. The extraction ratios ranged from about 0.4 to 1.0 (indicating existence of marked concentration gradient) and 0.1 to 0.6 for urea and vitamin B12, respectively. The H only serves as an "operator" in a given system, and the H value per unit length of the dialyzer coil can be shown to increase markedly with the length of coil, which is different from the basic assumption in the well-stirred model. For vitamin B12 the present clearance approach appears to be slightly superior to the "parallel-tube model".

Practicing in a university hospital. Perioperative nurses focus on patient care in a teaching setting

The contributions to this article show that the perioperative nurse has become a knowledgeable highly skilled practitioner. Nurses with different backgrounds, nationalities, educational preparation, and professional experience show that the outcome--excellent patient care--is more important than the process. Since the individual perioperative practitioner has implemented the nursing process, perioperative nursing care of patients has improved. The primary lesson that the UCIMC administrators learned was that there are many ways to accomplish goals. Administrators commended the perioperative nurses for their knowledge, risk taking, input and assessments related to problems and decisions, and for accepting challenges with enthusiasm and vigor. The administrators also learned that they need to be facilitating supporters more than supervisors in the OR. This creates an appropriate environment for effective practice. In this manner, the perioperative nurse can achieve both personal and professional satisfaction.

High-performance liquid chromatographic determination of prednisolone and its steroid 21-oate ester derivatives in rat plasma: pharmacokinetic applications

A high-performance liquid chromatographic (HPLC) technique was developed for the determination of prednisolone and its local anti-inflammatory steroid 21-oate ester derivatives in rat plasma. These new steroid esters (methyl 20 alpha- and 20 beta-dihydroprednisolonate; P4 alpha and P4 beta), developed for local use, were found to exhibit minimal systemic side effects as compared with prednisolone. The described method involves a simple organic extraction procedure and separation of steroids using a C18 reversed-phase column for pharmacokinetic study. The method allows simultaneous measurement of endogenous corticosterone following administration of P4 alpha, P4 beta, and prednisolone. The calibration curves of the steroids were linear over a wide range of concentrations (0.05 to 10 micrograms/mL). The limit of detection of the assay for all tested steroids is 10-20 ng/mL. The method is reproducible, with a coefficient of variation of less than 10% for all steroids over a wide range of concentrations. No interference from endogenous steroids nor exogenous steroids was found. The presented method is simple, rapid, specific, sensitive, and reproducible.

Periodate-oxidized 3-aminopyridine adenine dinucleotide phosphate as a fluorescent affinity label for pigeon liver malic enzyme

Treatment of 3-aminopyridine adenine dinucleotide phosphate with sodium periodate resulted in oxidation of the ribose linked to 3-aminopyridine ring and cleavage of the dinucleotide into 3-aminopyridine and adenosine moieties. These two moieties were separated by thin layer chromatography and were synergistically bound to pigeon liver malic enzyme (EC 1.1.1.40), causing inactivation of the enzyme. The inactivation showed saturation kinetics. The apparent binding constant for the reversible enzyme-reagent binary complex (KI) and the maximum inactivation rate constant at saturating reagent concentration (kmax) were found to be 1.1 +/- 0.02 mM and 0.068 +/- 0.001 min-1, respectively. L-Malate at low concentration enhanced the inactivation rate by lowering the KI value whereas high malate concentration increased the kmax. Mn2+ or NADP+ partially protected the enzyme from the inactivation and gave additive protection when used together. L-Malate eliminated the protective effect of NADP+ or Mn2+. Maximum and synergistic protection was afforded by NADP+, Mn2+ plus L-malate (or tartronate). Oxidized and cleaved 3-aminopyridine adenine dinucleotide phosphate was also found to be a competitive inhibitor versus NADP+ in the oxidative decarboxylation reaction catalyzed by malic enzyme with a Ki value of 4.1 +/- 0.1 microM. 3-Aminopyridine adenine dinucleotide phosphate or its periodate-oxidized cleaved products bound to the enzyme anticooperatively. Oxidized 3-aminopyridine adenine dinucleotide phosphate labeled the nucleotide binding site of the enzyme with a fluorescent probe which may be readily traced or quantified. The completely inactivated enzyme incorporated 2 mol of reagent/mol of enzyme tetramer. The inactivation was partially reversible by dilution and could be made irreversible by treating the modified enzyme with sodium borohydride. This fluorescent compound and its counterpart-oxidized 3-aminopyridine adenine dinucleotide may be a potential affinity label for all other NAD(P)+-dependent dehydrogenases.

Identification of the erythropoietin receptors of erythroleukemic cells

Erythropoietin (epo) is the physiologic regulator of red blood cell development. We have demonstrated the presence of epo receptors on two erythroleukemia cell lines, IW32 and IW201. IW32 produces epo constitutively while IW201 is a nonproducing cell line. Neither cell lines respond to epo to differentiate. In this study, we have shown that these cells bound 125I-epo specifically. Binding could be displaced by the presence of unlabeled epo but not by insulin or epidermal growth factor. In contrast to that found in epo responsive cells isolated from Friend virus infected mouse spleen, which were reported to contain both "high" and "low" affinity receptors, our finding indicated only a single class of "low" affinity receptors with apparent dissociation constants of 1.7 nM and 2.0 nM for IW32 and IW201 cell lines, respectively. It is suggested that the absence of "high" affinity receptors may account for the lack of responsiveness of these cells to epo.

Multiple coronary artery-left ventricular fistulas: a pattern of anomalous coronary microvascularization

Fistulas between the coronary artery and the left heart chambers are exceptionally rare, especially those emptying into the left ventricle. We know of 33 cases of coronary artery-left ventricular fistulas reported in the literature, 7 of which had multiple communications. The findings in 6 additional patients with multiple coronary artery-left ventricular fistulas are reported. Three of the 6 patients from all three major coronary arteries. It is important to recognize this anomaly as it may be the source of angina in patients without angiographic evidence of major atherosclerotic coronary artery disease.

Phosphocreatine, an intracellular high-energy compound, is found in the extracellular fluid of the seminal vesicles in mice and rats

High levels of phosphocreatine, a compound known to serve as an intracellular energy reserve, were found in the fluid contained in seminal vesicle glands. The concentrations of phosphocreatine in the extracellular fluid in the mouse and rat were found to be 5.6 +/- 1.6 and 2.2 +/- 0.8 mumol/g, respectively, which are higher than the intracellular levels reported for smooth muscles. The creatine concentrations in the seminal vesicular fluid from these two species were 22.8 +/- 3.1 and 13.0 +/- 5.3 mumol/g, respectively. These creatine levels are approximately 100 and 65 times higher than the creatine levels in mammalian blood. Smaller amounts of ATP (phosphocreatine/ATP ratio of 20-40) and traces of ADP were also found. Comparison of the pattern of distribution of macromolecules (proteins and DNA) with the distribution of phosphocreatine between the cells and the fluid of the seminal vesicle indicates that cell lysis did not account for the phosphocreatine in the seminal vesicle fluid. Rather, the available evidence strongly suggests that this high-energy compound is actively secreted. We found that in the testes, the sperm are exposed to the highest known creatine concentration in any mammalian tissue studied. Based on these results and other recent reports, we propose that the extracellular phosphocreatine, ATP, and creatine are involved in sperm metabolism.

Refractive-index dispersion of phosphosilicate glass, thermal oxide, and silicon nitride films on silicon

We present precise measurements of the refractive-index dispersion in the 0.6-1.5-microm range of dielectric films commonly used to form optical waveguides on Si. These are thermal SiO(2) and phosphosilicate glasses formed from several types of low pressure chemical vapor deposition and Si(3)N(4) formed by LPCVD. Mode refractive-index measurements were made with absolute accuracies of 1 x 10(-4). We show that for samples greater, similar3 microm thick, the error in the film refractive index, determined by extrapolation of the mode refractive index data of the lowest two modes, is less, similar1 x 10(-4). Annealing studies of the phosphosilicate glass samples show that films containing 2% or more of P reached their equilibrium refractive indices after annealing at 800 degrees C, while undoped silica films require annealing at 1100 degrees C to reach equilibrium.