Factor VIIa and the extracellular domains of human tissue factor form a compact complex: a study by X-ray and neutron solution scattering.

The four-domain structure of human factor VIIa and the two-domain structure of tissue factor form a tight complex to initiate blood coagulation. By solution scattering, the mean X-ray and neutron radii of gyration RG (which determine macro-molecular elongation) were found to be 3.25 nm, 2.

Mature teratoma of the uterine cervix with pulmonary differentiation.

Teratomas of the uterus are very rare, and a uterine teratoma with pulmonary differentiation has not, to our knowledge, been described previously. In this article, we report such a case in a 33-year-old woman, who presented with heavy vaginal bleeding and a polypoid mass of the uterine cervix. The cervical lesion was composed entirely of mature lung tissue, including bronchial, bronchiolar, and alveolar structures.

Structured sexual therapy with severely dissociative patients.

Individuals and couples often have a desire to increase their sexuality even in the face of severe past physical and sexual trauma. Requirements for effective therapy include the establishment of a safe environment, cooperation of a partner to allow the patient to be in control, and an exploration of past sexual abuse to avoid recapitulation that may trigger flashbacks or dissociative episodes. It is also helpful if permission is given to a sexualized ego fragment to become more assertive and help the patient reconcile sexuality as ego-syntonic.

Acidic and basic fibroblast growth factors have comparable effects on the haemostatic function of vascular endothelium.

Acidic and basic fibroblast growth factor (aFGF and bFGF respectively) are closely related mitogens (55% homology) of the heparin binding growth factor family. Reports of the relative potency of these growth factors and the ability of heparin to potentiate the activity of bFGF are conflicting. We have examined the effect of heparin and human recombinant aFGF and bFGF on basal and thrombin challenged release of metabolites from cultured human umbilical vein endothelial cells (HUVEC).

Molecular cloning of two different cDNAs for maize acetyl CoA carboxylase.

Acetyl CoA carboxylase (EC 6.4.1.

Studies on wheat acetyl CoA carboxylase and the cloning of a partial cDNA.

Wheat germ acetyl CoA carboxylase (ACCase) was purified by liquid chromatography and electroelution. During purification bovine serum albumin (BSA) was used to coat Amicon membranes used to concentrate partially pure ACCase. Despite further SDS-PAGE/electroelution and microbore HPLC steps BSA remained associated.

Botulinum A like type B and tetanus toxins fulfils criteria for being a zinc-dependent protease.

Although botulinum neurotoxin (BoNT) types A and B and tetanus toxin (TeTx) are specific inhibitors of transmitter release whose light chains contain a zinc-binding motif characteristic of metalloendoproteases, only the latter two proteolyse synaptobrevin. Chelation of zinc or its readdition at high concentration hindered blockade of neuromuscular transmission by BoNT/A and B, indicating that type A also acts via a zinc-dependent mechanism. Such treatments prevented proteolysis of synaptobrevin II in rat brain synaptic vesicles by BoNT/B and TeTx but only the activity of the latter was antagonised appreciably by ASQFETS, a peptide spanning their cleavage site.

Prosexual drugs: empirical status of the "new aphrodisiacs".

The search for an effective aphrodisiac has been a perennial pursuit of most societies throughout history. In the past decade, attention has focused increasingly on the prosexual effects of oral pharmacological agents with central neurotransmitter actions. The role of various dopaminergic, adrenergic, and serotonergic agents, in particular, has been intensively investigated in both human and animal studies.

Microtubule-dissociating drugs and A23187 reveal differences in the inhibition of synaptosomal transmitter release by botulinum neurotoxins types A and B.

The inhibitory effects of botulinum neurotoxins types A and B on Ca2(+)-dependent evoked release of [3H]noradrenaline from rat cerebrocortical synaptosomes were compared and their molecular basis investigated. A23187, a Ca2+ ionophore, proved more efficacious in reversing the blockade produced by type A than that by B, whereas the actions of neither were changed by increasing intraterminal cyclic GMP levels using 8-bromo-cyclic GMP of nitroprusside. Disruption of the actin-based cytoskeleton with cytochalasin D did not alter the inhibition seen subsequently with either toxin.

ADP-ribosylation of cerebrocortical synaptosomal proteins by cholera, pertussis and botulinum toxins.

Certain microbial toxins ADP-ribosylate G proteins that may be related to those postulated to participate in secretion, whilst botulinum neurotoxins, produced by Clostridium botulinum, block Ca2(+)-dependent neurotransmitter release. Thus, botulinum, pertussis and cholera toxins were examined for ADP-ribosyl transferase activity using isolated nerve terminals. Although type D botulinum, cholera and pertussis toxins exhibited such enzymic activity, this was not detectable with types A or B botulinum neurotoxins or their individual chains, in any synaptosomal fraction.

Clues to the multi-phasic inhibitory action of botulinum neurotoxins on release of transmitters.

1. With the aim of gaining insight into the mechanism of Ca2(+)-dependent secretion, inhibition of transmitter release by botulinum neurotoxins or their fragments was studied at mammalian motor nerve terminals, cerebrocortical synaptosomes and PC-12 cells. 2.

Choreoathetosis induced by cyproheptadine.

Cyproheptadine is an antihistamine with antiserotoninergic and anticholinergic properties. It is a relatively safe drug with many varied indications for usage, which rarely produces serious adverse neurologic sequelae. Reports of involuntary movement disorder secondary to cyproheptadine are rare.

Characterization of the inhibitory action of botulinum neurotoxin type A on the release of several transmitters from rat cerebrocortical synaptosomes.

Under optimised conditions for intoxication, botulinum neurotoxin type A was shown to inhibit approximately 90% of Ca2+-dependent K+-evoked release of [3H]acetylcholine, [3H]noradrenaline, and [3H]dopamine from rat cerebrocortical synaptosomes; cholinergic terminals were most susceptible. In each case, the dose-response curve for the neurotoxin was extended, with about 50% of evoked release being inhibited at approximately 10 nM whereas 200 nM was required for the maximal blockade. This may suggest some heterogeneity in the release process.

Leukocyturia in cyclosporine-treated renal allograft recipients.

Five hundred eighty-seven daily urine specimens were examined from 179 consecutive renal allograft recipients with the use of quantitative cytodiagnostic urinalysis. Specimens were divided between those patients receiving cyclosporine (CyA) and steroid immunotherapy (73 patients) and those receiving standard azathioprine (Aza) and steroid immunotherapy (106 patients). When patients with urinary tract infections were excluded, an increase in leukocyturia was observed in the CyA-treated patients.

Botulinum toxin A blocks glutamate exocytosis from guinea-pig cerebral cortical synaptosomes.

The exocytotic release of L-glutamate from guinea-pig cerebral cortical synaptosomes can be extensively inhibited by preincubation with botulinum neurotoxin type A at 37 degrees C for 1-2 h. The toxin has no effect on synaptosomal respiratory control, respiratory capacity, ATP synthesis, plasma-membrane 86Rb+ permeability or plasma-membrane potential, does not inhibit the entry of 45Ca2+ into the synaptosome upon depolarization and does not alter the ability of intrasynaptosomal mitochondria to sequester Ca2+. The blockade of Ca2+-dependent glutamate release may be totally reversed by the Ca2+/2 H+-exchange ionophore ionomycin, but not by increasing extracellular Ca2+ concentration.

Health risk appraisal in primary care.

Preventive medicine focuses on the identification of factors that will lead to disability or disease and then the discovery of ways to eliminate or at least minimize these risk factors. In this article, the authors outline a guide for primary health care practitioners to practice preventive medicine using a computerized individual risk appraisal.

A sensitive and useful radioimmunoassay for neurotoxin and its haemagglutinin complex from Clostridium botulinum.

A sensitive radioimmunoassay for the detection of botulinum toxin, produced by Clostridium botulinum, was developed. This employs homogeneous botulinum neurotoxin type A and its 125I-labelled derivative of high specific radioactivity, rather than its complex with haemagglutinin as used hitherto. The sensitivity of the assay is 1 ng of neurotoxin per ml, which is equivalent to 80 LD50 units (half-lethal doses) in mice.

Regulation of C4 photosynthesis: inactivation of pyruvate, Pi dikinase by ADP-dependent phosphorylation and activation by phosphorolysis.

These studies provide information about the mechanism of the light/dark-mediated regulation of pyruvate, Pi dikinase (EC 2.7.9.

An affinity label for the regulatory dithiol of ribulose-5-phosphate kinase from maize (Zea mays).

Ribulose-5-phosphate kinase from maize (Zea mays) can exist in either a reduced, active form or an oxidized, inactive form. Reduced ribulose-5-phosphate kinase is rapidly and irreversibly inactivated by the dichlorotriazine dye Reactive Red 1 (Procion Red MX-2B), but the irreversible inactivation of the oxidized form of ribulose-5-phosphate kinase occurs at only 0.05% of this rate.

Regulation of C4 photosynthesis: regulation of activation and inactivation of NADP-malate dehydrogenase by NADP and NADPH.

Inactive NADP-malate dehydrogenase (disulfide form) from chloroplasts of Zea mays is activated by reduced thioredoxin while the active enzyme (dithiol form) is inactivated by incubation with oxidized thioredoxin. This reductive activation of NADP-malate dehydrogenase is inhibited by over 95% in the presence of NADP and the Kd for this interaction of NADP with the inactive enzyme is about 3 microM. Other substrates of the enzyme (malate, oxaloacetate, or NADPH) do not effect the rate of enzyme activation but NADPH can reverse the inhibitory effect of NADP.

Regulation of C4 photosynthesis: physical and kinetic properties of active (dithiol) and inactive (disulfide) NADP-malate dehydrogenase from Zea mays.

NADP-malate dehydrogenase was purified from leaves of Zea mays in the absence of thiol-reducing agents by (NH4)2SO4, polyethylene glycol, and pH fractionation followed by dye-ligand affinity chromatography and gel filtration. The purified enzyme is completely inactive (no activity detected between pH 6 and 9) but can be reactivated by thiol-reducing agents including dithiothreitol and thioredoxin. The active enzyme shows distinctly alkaline pH optima when assayed in either direction; Km values at pH 8.