Resonance Raman spectroscopy indicates a lysine as the sixth iron ligand in cytochrome f

The resonance Raman spectrum of turnip cytochrome f is similar to that of other c-type cytochromes with the exception of a single band at 1532 cm-1 which is shifted to lower frequency relative to its position (1542-1545 cm-1) in other c-type cytochromes. Comparison of the frequency of this band with that in alkylated cytochrome c at high pH suggests that the sixth heme iron ligand in cytochrome f is a deprotonated lysine amino group rather than a methionine sulfur. Comparison of the amino-acid sequences of cytochromes f and c1 suggests lysine-145 as a likely candidate for the sixth heme iron ligand in cytochrome f.

Chronic treatment with beta adrenergic agonists and antagonists alters the composition of proteins in rat parotid saliva

This investigation was undertaken to determine the role of beta-adrenergic receptors in the regulation of the protein composition of rat parotid saliva. Chronic treatment of rats with dobutamine, a beta 1-adrenergic agonist, resulted in changes in parotid saliva volume, protein concentration, and composition which were essentially the same as those changes which occurred following chronic treatment with isoproterenol, a non-specific beta-adrenergic agonist. Chronic treatment with the beta 2-adrenergic agonist, terbutaline, had no effect on parotid saliva volume, protein concentration, or composition. Chronic treatment of rats with a beta 1-adrenergic antagonist, metoprolol, had different effects on saliva dependent on the manner by which the drug was delivered. Twice-daily injections of metoprolol led to a decrease in flow rate, but protein concentration and composition were unaltered. When metoprolol was delivered by surgically implanted osmotic minipumps, neither the flow of parotid saliva nor its concentration of protein was altered; however, there was a reduction in the proportion of proline-rich proteins in saliva. Comparable changes in parotid saliva protein composition occurred when the minipumps delivered propranolol, a non-specific beta-adrenergic antagonist. Chronic treatment of rats with an alpha 2-adrenergic agonist (clonidine) or antagonist (yohimbine) was without effect on parotid saliva flow rate, protein concentration, or composition. These findings suggest that the synthesis of proline-rich proteins is regulated, in part, by beta-adrenergic receptor stimulation, and primarily by the beta 1-receptor subtype.

4-Hydroxybutyric aciduria in a patient without ataxia or convulsions

A child presenting with mild psychomotor retardation, hypotonia, microcephaly and hyperkinesis is described. Urinary organic acid analysis by combined gas chromatography-mass spectrometry revealed 4-hydroxybutyric aciduria. Succinic semialdehyde dehydrogenase activity in extracts of white cells derived from the patient was less than 10% of control values.

Influence of thyroxine in the regulation of rat parotid salivary protein composition

This study tested the role of thyroxine in the regulation of the protein composition of rat parotid saliva. Thyro-parathyroidectomy was performed on two groups of rats, one of which subsequently received thyroxine replacement; the third group was sham-operated. Parotid saliva was collected on the eighth day after surgery, with pilocarpine and isoproterenol used as a secretory stimulus. The volume of saliva collected in 30 min from the thyro-parathyroidectomized rats was 55% less than that collected from sham-operated rats. In the thyro-parathyroidectomized rats, the protein concentration as measured by absorption at 215 nm was unaltered, but that measured by the Lowry procedure was 43% higher. Spectrophotometric scans of Coomassie Blue-stained gels following sodium dodecylsulfate polyacrylamide gel electrophoresis of the secreted proteins showed an 18% reduction in the proportion of protein attributable to amylase and a 43% reduction in proportion of acidic and basic proline-rich proteins following thyro-parathyroidectomy; deoxyribonuclease and two other major secretory proteins (Fraction I and Fraction V) were increased (38%, 20%, and 46%, respectively). These changes in flow rate, protein concentration by the Lowry assay, and protein composition were prevented by treatment of thyro-parathyroidectomized rats with thyroxine replacement and are in opposition to those changes we reported earlier for hyperthyroid rats. The results indicate that the flow of saliva as well as the synthesis of the various salivary proteins are influenced by thyroxine.

Bronchial leukocyte proteinase inhibitor levels in bronchial washings in asthma patients

To evaluate whether epithelial damage of airways in asthma could be related to diminished levels of the low molecular weight bronchial leukocyte proteinase inhibitor (BLPI) in airways, we determined BLPI in bronchial washings of 13 asthma patients and 13 healthy subjects, using a sensitive enzyme-linked immunoassay. The patients had asthma due to western red cedar and had bronchial washings done 24 to 48 hours after a mild to moderate asthmatic reaction induced by inhalation challenge. We did not find significant differences in BLPI concentrations in lavage fluid of asthma patients and healthy control subjects. The ratios of BLPI to albumin levels in bronchial washings appeared to be lower among asthmatic patients, but this difference was mainly due to an increase in albumin levels in lavage fluid in asthma. In addition, there were no significant differences in BLPI levels in washings obtained from main and segmental bronchi in both control subjects and asthma patients.

Determination of intrinsic membrane transport parameters from perfused intestine experiments: a boundary layer approach to estimating the aqueous and unbiased membrane permeabilities

A boundary layer approach is developed for estimating the aqueous resistance in a perfused rat intestine experiment. Knowing the aqueous resistance allows the membrane surface concentration to be calculated as a function of the perfusate inlet concentration and perfusional flow rate. Determination of membrane uptake as a function of the membrane surface concentration rather than the perfusate concentration gives the intrinsic, unbiased membrane parameters for the uptake mechanism of Michaelis-Menten-type kinetics in parallel with passive diffusion. The aqueous resistance derived in the analysis is verified by comparison with flux data for 1-leucine and progesterone measured at various flow rates and intestinal lengths. The approach allows for a direct estimate to be made of the unbiased membrane permeability parameters.

Membrane permeability parameters for some amino acids and beta-lactam antibiotics: application of the boundary layer approach

The boundary layer approach to analyzing the results of the perfused intestinal segment method of measuring membrane permeabilities is applied to the amino acids; leucine, valine, phenylalanine, lysine and aspartic acid and the beta-lactam antibiotics, cephalexin and penicillin V. The analysis indicates that in determining the membrane parameters, Pw vs. Cw data are preferable to using Jss = PwCw vs. Cw data. It is further shown that the carrier permeability, Pc* = Jmax*/Km, may be the most significant parameter to consider since luminal amino acid or drug concentration may generally be below the Km value. A comparison of P*c values for the beta-lactams with results for passively absorbed compounds indicates that the cephalosporins would be expected to be well absorbed orally based on the perfusion results. This suggests that this approach may be useful in estimating oral drug absorption for compounds that are absorbed passively as well as by a carrier-mediated mechanism.

Regulation of intraganglionic synapses among rabbit parasympathetic neurones

1. The response of parasympathetic neurones to the removal of preganglionic innervation was studied in the ciliary ganglia of adult rabbits. After section of the preganglionic oculomotor nerve, individual ciliary neurones were characterized electrophysiologically by intracellular recording, and morphologically by intracellular injection of horseradish peroxidase. 2. Within the first 24-48 h after nerve section, only two of fifty-nine neurones responded to antidromic stimulation of the postganglionic ciliary nerve with synaptic potentials. This result indicates that synaptic connections between principal neurones are rare in normal ganglia. 3. One week after denervation, however, excitatory postsynaptic potentials were recorded in thirty-nine out of fifty-three cells examined. Thus there is a rapid and extensive formation of intraganglionic connections after denervation. Morphological analysis of these ganglion cells showed numerous fine processes arising from the cell bodies and dendrites; such neurites were not present among control neurones. Many of these newly formed processes appeared to form synapses on neighbouring cells. 4. A similar proportion of neurones (about two-thirds of the cells) showed antidromically evoked excitatory postsynaptic potentials 2 weeks after denervation. Dendrites were still longer and more complex than controls at this time. After several months the morphology and prevalence of intraganglionic connections returned to normal as the ganglion became reinnervated. 5. Thus, denervation of rabbit ciliary ganglion cells induces the rapid formation of large numbers of functional synaptic connections among ganglion cells. It is postulated that local regulatory factors govern connections between parasympathetic ganglion cells. After denervation, these trophic signals are no longer modulated by presynaptic axons and they exert a stimulus for sprouting and synapse formation among this population of cholinergic neurones.

The significance of depression in the prediction of relapse in chronic schizophrenia

The prospective monitoring of two separate groups of chronically schizophrenic patients on regular depot maintenance therapy suggests that depression developing after an interval of 1 year from recovery from an acute relapse indicates a significant increase in the risk of a further relapse within 2 years, compared with depression within the first year, or no depression. Patients with such depression were more prone to relapses than other patients, despite regular medication within normal dose ranges. The results suggest that the aetiology of depression occurring in patients after 1 year in a stable mental state is different from that of depression within the first year, and in many patients, the former represents underlying schizophrenic activity prior to an early relapse.

Development and evaluation of an attentional test for head injured children--1. Information processing capacity in a normal sample

The Children's Paced Auditory Serial Addition Task (CHIPASAT) was developed to assess the capacity and rate of information processing in children. This basic aspect of attention underlies many abilities, and is impaired following head injury in adults. Similar impairment may occur in children after head injury or other CNS dysfunction. A sample (N = 315) of normal school children was assessed with the CHIPASAT to establish normative data, and relationships between age, arithmetic ability, general intellectual (g) ability and information processing capacity. The results suggest that the age and, to a lesser extent, the arithmetic ability of a child have a significant influence on information processing capacity. The children's general intellectual ability (g) and sex were unrelated to CHIPASAT performance.

Purification and characterization of four monofluorescein cobra alpha-toxin derivatives

We labeled cobra-alpha-toxin (Naja naja siamensis 3) with near stoichiometric quantities of fluorescein isothiocyanate. To reduce labeling of the hyperreactive N epsilon-lysine 23, the alpha-toxin was modified reversibly with citraconic anhydride before fluorescein labeling. The citraconic anhydride was later removed with strong acid, and four of the six possible monofluorescein alpha-toxin derivatives were isolated by isoelectric focusing on an immobilized pH gradient. Thermolysin digestion and subsequent high pressure liquid chromatography of the peptides yielded one dominant fluorescent peak from three of the isolated monofluorescein derivatives. Sequence analyses of these three fluorescent peaks indicated monofluorescein labeling at Lys-69, Lys-35, and Lys-49. Since one derivative (not identified by sequence analysis) displayed essentially identical chromatographic, spectroscopic, and binding properties as our previously identified monofluorescein-Lys-23 toxin (Johnson, D. A., and Taylor, P. (1982) J. Biol. Chem. 257, 5632-5636), we identified the site of labeling of this fourth derivative to be Lys-23. While only small differences were observed in the extinction maxima and molar extinction coefficients, the quantum yields of the isolated derivatives varied markedly and ranged between 0.18 and 0.41. Binding of monofluorescein-Lys-69, -Lys-35, -Lys-49, and -Lys-23 derivatives to the membrane-associated acetylcholine receptor from Torpedo californica was associated with -39, -26, -9, and +96% changes in fluorescence emission intensity, respectively. Based on analyses of the kinetics of fluorescence changes associated with receptor binding, the association and dissociation rate constants were measured. Relative to native cobra alpha-toxin, monofluorescein conjugation reduced the bimolecular association rate constants for binding to the receptor 13-33-fold. The dissociation rate binding rate constants were less affected and were reduced 0-5-fold.

Bronchial leukocyte proteinase inhibitor: hydrodynamic properties and interaction with alpha 2-macroglobulin-bound elastase

Bronchial leukocyte proteinase inhibitor (BLPI) is an 11.7 kDa, acid-stable protein found in mucous secretions, which inhibits neutrophil elastase. The Stoke's radius of BLPI calculated from sedimentation equilibrium and sedimentation velocity centrifugation data was in good agreement with the value determined by gel filtration. These data indicate that BLPI exists in a compact globular conformation at both neutral and acidic pH. BLPI, due to its small compact size, can inhibit neutrophil elastase after the enzyme has been complexed with alpha 2-macroglobulin (A-2-M) but alpha 1-proteinase inhibitor failed to inactivate A-2-M-bound elastase. The apparent association rates of BLPI and Eglin C with A-2-M-bound elastase were found to be 6.3 X 10(2) M-1s-1 and 1.1 X 10(3) M-1s-1, respectively. These apparent association rates decreased 168-fold for BLPI and 909-fold for Eglin C, relative to the association rates of these inhibitors with free elastase. These changes probably result from a combination of effects, such as inhibitor accessibility to the enzyme and/or reaction rate, but regardless of the mechanism these data suggest that BLPI may function to control both free and A-2-M-bound elastase.

Observations on the use of depot neuroleptics in schizophrenia

This paper reviews some of the advantages and disadvantages of long-term maintenance therapy with neuroleptics in schizophrenia. The need to separate first-illness schizophrenia from chronic schizophrenia is illustrated. The reduction in the risk of a further acute relapse with continued medication and the likely duration of maintenance therapy are discussed. The true meaning of a further relapse to the patient in terms of reduced social and work function is also discussed. The advantages of using long-acting depot injections for drug administration are stressed. The complex issue of the correct dosage for maintenance is reviewed, with no proven advantage for either very high doses or very low doses. The frequency of depressive symptoms in schizophrenia is reviewed and the possible aetiologies discussed. The decision to use short- or long-term drug therapy, and whether to use a particular method of drug administration (oral or long-acting depot injections) should be separate issues. Depot injections may, on occasions, be the appropriate method of drug administration for short-term therapies, just as oral drugs have a place in the longer-duration maintenance treatments.

Changes in rat parotid saliva protein composition following chronic reserpine treatment and their relation to inanition

Chronic administration of the catecholamine-depleting agent, reserpine (0.5 mg/kg), resulted in a reduction in food intake after 3 days. To differentiate effects of the drug from those of reduced food intake a pair-fed group, whose daily caloric intake was restricted to the amount consumed by the reserpine-treated rats, was included. After 7 days, both the reserpine-treated and pair-fed control exhibited a marked reduction in the volume of saliva collected in a 30 min interval following a secretory stimulus compared to untreated ad libitum-fed controls, and the proportion of salivary proteins attributable to acidic and basic proline-rich proteins and to minor 1b protein were decreased whereas deoxyribonuclease was increased. For two of the salivary proteins (fractions I and V) changes for the reserpine-treated and pair-fed groups were different. Fraction I was reduced in both groups, but exhibited a greater decrease in the pair-fed than in the reserpine-treated, whereas fraction V was significantly increased only in the pair-fed group. Thus many of the salivary changes associated with reserpine treatment may have resulted from the change in feeding habits and not from reserpine treatment per se. The study demonstrates the importance of controlling for food intake under experimental circumstances which may lead to a marked change in daily feeding habits.

Transthoracic needle aspiration biopsy. Review of 233 cases

In 233 cases in which transthoracic needle aspiration was done at the Mayo Clinic from 1980 through 1983, the cytology slides, tissue fragments and patient histories were reviewed; the original and review diagnoses were compared and correlated with the subsequent clinical course. In most cases, the procedure was performed with an 18-gauge needle under fluoroscopic guidance, primarily in cases with suspected malignant masses that were considered to be not surgically resectable. In 70% of the cases, there was a history of malignancy, and 82% of the malignant lesions were of extrapulmonary origin. Correlation of the original diagnosis with the clinical course yielded 70% (164 cases) true positives, 6% (14 cases) true negatives, 16% (37 cases) false negatives, 0% false positives and 8% (18 cases) indeterminants. In none of the false-negative cases was the slide subsequently read as positive in a blind review. Of the true-positive cases, 12% had positive tissue fragments only, 37% had positive cytology smears only, and 51% had both positive smears and fragments. In 32% of the cases, there were radiologically demonstrable pneumothoraces, and in 12%, placement of a chest tube was required. Hemoptysis occurred in less than 5% of the cases. In summary, transthoracic needle biopsy provides an efficient way to accurately obtain diagnostic tissue, with acceptable minor complications.

In vivo antitumor activity demonstrated with squamous carcinoma reactive monoclonal antibody-Vinca immunoconjugates

An immunoconjugate (PF1/D-DAVLBHYD), made with the squamous carcinoma reactive monoclonal antibody PF1/D and a derivative of vinblastine, DAVLBHYD, was shown to suppress established T222 human tumor nude mouse xenografts using a multidose protocol. Treatments of xenograft-bearing mice with free drug, free antibody, or a mixture of the two, were unsuccessful at achieving suppression without associated toxicity, using otherwise identical protocols. A Vinca conjugate with a related squamous carcinoma reactive monoclonal antibody, PF1/B, was shown to have similar tumor suppressive activity. In a dual immunoconjugate therapy protocol, PF1/D-DAVLBHYD and PF1/B-DAVLBHYD had additive antitumor effects which were consistent with their complementary tumor reactivity.

Double-blind comparison of half-dose and standard-dose flupenthixol decanoate in the maintenance treatment of stabilised out-patients with schizophrenia

A double-blind controlled trial of 50% dose reduction in maintenance treatment in stable out-patients with low BPRS scores and good social function shows a significantly higher relapse rate in the low-dose group at 12 months (P less than 0.05). After an interval of 24-36 months from dose reduction, 56-76% had experienced a relapse and 76-79% had resumed their former dosage. No clear advantage was shown for the lower dose in either a reduction of side-effects or improved social function, but a reduced prevalence or lower rate of symptom emergence for tardive dyskinesia was suggested.

Social adjustment and interaction after severe head injury: II. Rationale and bases for intervention

Social anxiety, social performance and self-esteem are suggested to be important factors in the social adjustment of severely head-injured patients. The present study attempted to remediate some of these deficits in social interaction and adjustment by adopting theoretical models of the development of self-understanding, and of the general process of recovery from head injury, together with the application of existing methodology from social skills training. Reassessment after one year of group treatment did not show any statistically significant results, but some important individual changes in social performance and social anxiety were found. Reasons for the apparent failure to change are discussed, with recommendations for more intensive treatment and refinement of measures.

Cardiac myocyte guanosine transport and metabolism

Guanosine transport and metabolism were examined in adult rat cardiac myocytes. Myocytes transported guanosine via saturable [Km = 18 microM, maximum velocity (Vmax) = 3.61 pmol.mg-1.s-1] and nonsaturable (rate constant = 1.47 X 10(-2] processes. The saturable process was inhibited by nitrobenzyl-thioinosine, inosine [inhibition constant (Ki) = 180 microM], and adenosine (Ki = 112 microM). Extracellular guanosine taken up by myocytes was slowly phosphorylated to guanine nucleotides. The majority of guanosine (98%) existed as free intracellular guanosine after 60 s. Countertransport of nucleosides could not be demonstrated in these cells at physiological concentrations in the presence of up to a 10-fold gradient of nucleoside. These studies indicate that adult rat cardiac myocytes can be used to assess myocardial guanosine transport separate from its metabolism. Comparable inhibition of guanosine and adenosine transport by each other and by inosine support the hypothesis that guanosine and adenosine are transported by a common carrier.

Properties of the 18-MV photon beam from a dual energy linear accelerator

The beam characteristics of the 18-MV photon beam of a Varian Clinac 1800 are presented. The clinically relevant parameters of central axis depth dose, tissue-phantom ratios, peak-scatter factors, and relative output factors are discussed and compared to 18-MV beam data previously reported. The nominal beam energy was found to be 18.3 +/- 0.8 MV on the central axis. The beam symmetry and uniformity meet the manufacturer's specifications. The inverse-square law is applicable within 1.4% over the clinically useful range of distances and field sizes. An empirical fit equation for the central axis depth dose is presented.

Decidium. A novel fluorescent probe of the agonist/antagonist and noncompetitive inhibitor sites on the nicotinic acetylcholine receptor

We have examined the interaction of the nicotinic acetylcholine receptor with decidium diiodide, a bisquaternary analogue of ethidium containing 10 methylene groups between the endocyclic and trimethylamino quaternary nitrogens. Decidium inhibits mono-[125I]iodo-alpha-toxin binding, inhibits agonist-elicited 22Na+ influx in intact cells, augments agonist competition with mono-[125I]iodo-alpha-toxin binding, and enhances [3H]phencyclidine (PCP) binding to a noncompetitive inhibitor site. These effects occur over similar concentration ranges (half-maximum effects between 0.1 and 0.4 microM). Thus, decidium binds to the agonist site and converts the receptor to a desensitized state exhibiting increased affinity for agonist and heterotropic inhibitors. These properties are similar to metaphilic antagonists characterized in classical pharmacology. At higher concentrations decidium associates directly with the noncompetitive inhibitor site identified by [3H]phencyclidine binding. Dissociation constants of decidium at this site in the resting and desensitized states are determined to be 29 and 1.2 microM, respectively. Analysis of fluorescence excitation and emission maxima reveal that binding to both the agonist and noncompetitive inhibitor sites is associated with approximately 2-fold enhancement of fluorescence. The excitation maximum for decidium bound at the agonist site appears at 490 nm while that for decidium bound at the noncompetitive inhibitor site appears at 530 compared to 480 nm in buffer. These results suggest that decidium experiences a more hydrophobic environment upon binding to the nicotinic acetylcholine receptor sites, particularly to the noncompetitive inhibitor site. Fluorescence energy transfer between N'-fluorescein isothiocyanate-lysine-23 alpha-toxin (FITC-toxin), and decidium is not detected when each is bound to one of the two agonist sites on the receptor. This allows a minimal distance to be estimated between fluorophores. In contrast, energy transfer is observed between decidium nonspecifically associated with the membrane or with nonspecific sites and the FITC-toxin at the agonist sites.

Rapid isolation of human kininogens

A rapid, two-step procedure is described for the isolation of both "high molecular weight" (H-) and "low molecular weight" (L-) plasma kininogens from a single sample of plasma. Affinity chromatography on carboxymethyl-papain-Sepharose is used, together with high-resolution anion exchange chromatography.

Regulation of parotid salivary proteins by glucocorticoids

Previous studies have indicated that adrenal-intact rats treated for one week with pharmacological doses of the synthetic glucocorticoid, dexamethasone, show a significant reduction in the proportion of proline-rich proteins and an increase in the proportion of amylase in rat parotid saliva (Johnson et al., 1987). In order to understand more fully the role of glucocorticoids in the regulation of salivary proteins, we performed bilateral adrenalectomies on groups of rats. Some of the adrenalectomized rats were treated with replacement-level doses of the synthetic glucocorticoid, dexamethasone. The food intake was monitored daily for both groups, and sham-operated pair-fed controls were included so that the effects of alterations of food intake could be separated from those of the experimental procedures. After eight to 12 days, uniformly stimulated parotid saliva was collected from these animals as well as from sham-operated controls fed ad libitum. The volume of saliva collected in 30 min was recorded, and the saliva samples were analyzed for concentration and composition of protein. Although the volume of saliva was not affected, parotid saliva collected from adrenalectomized rats exhibited a two-fold greater proportion of proline-rich proteins and reductions in other major secretory proteins: DNase, Fraction I, and Fraction V. The parotid gland secretory granules of adrenalectomized rats were more electron-lucent than in the ad libitum-fed controls. Treatment of adrenalectomized rats with dexamethasone largely prevented the changes in salivary protein composition as well as the alterations in secretory granule morphology.(ABSTRACT TRUNCATED AT 250 WORDS)