Hyperalgesia during acute opioid abstinence: evidence for a nociceptive facilitating function of the rostral ventromedial medulla

Naloxone-precipitated opioid abstinence is associated with enhancement of reflex responses to noxious stimulation (hyperalgesia). The present experiments in lightly anesthetized rats were designed to determine (1) whether neurons in the rostral ventromedial medulla (RVM) contribute to this enhancement, and (2) whether this enhancement is due to removal of an inhibitory modulatory influence or to activation of a facilitatory influence. In the first experiment, 10 micrograms of morphine was microinjected into the RVM; subsequent administration of naloxone (1 mg/kg, i.v.) shortened tail-flick latency. This is evidence that a synaptic action of opioids within the RVM can contribute to hyperalgesia. In the second experiment, systemic administration of morphine (2 mg/kg, i.v.) was followed by systemic administration of naloxone (1 mg/kg, i.v.), which produced a significant hyperalgesia that could be markedly attenuated by microinjection of 10 micrograms lidocaine into the RVM. That inactivation of RVM reduces the hyperalgesia indicates that the CNS is capable of generating a facilitating action on nociceptive transmission. Previous studies from this laboratory have indicated that a population of RVM neurons, on-cells, shows increased activity during opioid abstinence. The present experiments support the hypothesis that RVM on-cells exert a facilitating influence on nociceptive transmission.

Methotrexate in rheumatoid arthritis: effects on disease activity in a multicenter prospective study

One hundred and twenty-three patients with rheumatoid arthritis (RA) who successfully completed a randomized trial comparing oral methotrexate (MTX) to auranofin enrolled in a longterm prospective study of oral MTX. Of the 91 patients who completed 24 months of therapy, a significant (p = 0.0001) improvement was noted compared to baseline in all clinical disease variables and the Westergren erythrocyte sedimentation rate (ESR). Marked improvement occurred in 94 (76%) and 98 (80%) of the patients in the joint pain/tenderness index and joint swelling index at the last evaluable visit (mean 26 months). Of the 77 patients with an elevated ESR at baseline, 29 (38%) patients normalized it (less than 20 mm/h) while receiving therapy (p less than 0.01). A significant reduction in prednisone dose was also seen. Adverse events occurred frequently but were generally mild in severity. Twenty-seven patients (22%) withdrew during the study. Four (3%) withdrew due to lack of efficacy, and 6 (5%) because of adverse experiences. The overall probability of continuing therapy in the study for 48 months was projected at 72%. This large prospective study supports the observation of earlier smaller studies that MTX is an effective drug in the treatment of RA.

The mechanism of sunlight-mediated inactivation of Bacillus thuringiensis crystals

Detailed photostability studies were carried out using purified delta-endotoxin crystals from Bacillus thuringiensis subspecies HD-1 and HD-73. The mechanism and time course of sunlight inactivation was investigated by: (a) monitoring the tryptophan damage in the intact crystals by Raman spectroscopy, (b) amino acid analysis and (c) biological assays using insects. The results demonstrate that, for purified HD-1 or HD-73 crystals, the 300-380 nm range of the solar spectrum is largely responsible for bringing about crystal damage and consequent loss of toxicity. Purified Bacillus thuringiensis crystals that were exposed to fermentation liquor after cell lysis were more quickly degraded by sunlight than were crystals from cells that were lysed in water. This effect is attributed to adsorption of chromophores by crystals exposed to the fermenter liquor and the subsequent ability of these chromophores to act as photosensitizers. The importance of a photosensitization mechanism in crystal degradation was further emphasized by irradiating Bacillus thuringiensis crystals in vacuo. The latter crystals were found to be less damaged (20% tryptophan loss after 24 h irradiation by the solar spectrum) compared with crystals from the same sample irradiated in air (60% (60% tryptophan loss). Other methods of decreasing exposure of the crystals to oxygen, e.g. by using glycerol as a humectant, were also found to be successful in controlling photodamage. The results concerning photodegradation support a photosensitization mechanism involving the presence of exogenous (and possibly endogenous) chromophores which create singlet oxygen species upon irradiation by light.

A non-cytotoxic suppressor of immunoglobulin synthesis and secretion by B cells of normal humans and patients with rheumatoid arthritis and systemic lupus erythematosus

A factor secreted by thymocytes of immunized rabbits totally suppressed both the initiation of, and ongoing synthesis and secretion of, lectin (PWM)-induced synthesis of IgM and IgG immunoglobulins by the circulating B lymphocytes of normal humans, and of twenty consecutive patients with rheumatoid arthritis and twelve consecutive patients with systemic lupus erythematosus. The suppressor factor, referred to as human Ig synthesis/secretion suppressor factor or HISSF, is not HLA restricted in its activity and is not cytotoxic to the circulating human mononuclear cells (B cells, T cells, Null cells and monocytes). It was demonstrated that T cells precultured with HISSF were transformed into suppressor cells which, when added to fresh cultures of autologous B cells, suppressed the synthesis and secretion of IgM and IgG. On the basis of its suppressive and non-cytotoxic properties in vitro, HISSF may be an effective immunosuppressant in the treatment of patients with autoimmune diseases.

Folding and unfolding of the protoxin from Bacillus thuringiensis: evidence that the toxic moiety is present in an active conformation

The action of trypsin or papain on the 130-kDa crystal protein (protoxin) from Bacillus thuringiensis subsp. kurstaki HD-73 yields a 67-kDa proteinase-resistant toxic fragment (toxin) which is derived from the N-terminal half of the molecule. Sensitivity to proteolysis and fluorescence emission spectroscopy showed that the toxin unfolded to a much greater extent in 6 M guanidinium chloride (GuHCl) than in 8 M urea. Protoxin also unfolded extensively in 6 M GuHCl, whereas in 8 M urea only the C-terminal half of the molecule had unfolded extensively. Both unfolded protoxin and unfolded toxin refolded to their native and biologically active conformations. The biphasic unfolding observed for protoxin suggests that the C-terminal half of the molecule unfolded rapidly, whereas the N-terminal toxic moiety unfolded at a much slower rate, similar to that of the free 67-kDa toxin. A 67-kDa fragment, derived from the N-terminal half of the molecule, could be generated from the protoxin in the presence of either urea or GuHCl by treatment with proteinases. Compared to toxin in denaturants, this fragment was found to be more sensitive to proteolysis. However, on removal of the denaturants the fragment had the same proteinase resistance and cytolytic activity as native toxin. The increased proteinase sensitivity of the fragment generated in the presence of denaturants appears to be due to a perturbation in the conformation of the N-terminal toxic moiety. This perturbation is attributed to the unfolding of the C-terminal region of the protoxin prior to its proteolysis to yield the 67-kDa fragment.(ABSTRACT TRUNCATED AT 250 WORDS)

Octapeptide segments from the amino terminus of glycophorin A contain the antigenic determinants of the M and N blood groups systems

Human red blood cells with phenotype N/N and M/M were tested in an agglutination assay with anti-N and anti-M antibodies, respectively. After incubation of the synthesized octapeptide (Leu-Ser-Thr-Thr-Glu-Val-Ala-Met) from the N-amino terminus of glycophorin A, with anti-N antibody, there was significant inhibition of the agglutination of the N-positive cells. There was also inhibition of the agglutination of the M-positive cells with anti-M antibody by the synthesized octapeptide (Ser-Ser-Thr-Thr-Gly-Val-Ala-Met) from the M-amino terminus of glycophorin A. There was no inhibition, however, of the agglutination of M-positive cells with anti-M antibodies by the N-amino terminal octapeptide. Likewise, the M-amino terminal octapeptide did not inhibit agglutination of N-positive cells with anti-N. Because the synthesized octapeptides contained no carbohydrate, the anti-N and anti-M specificity appears to be determined principally by the peptides themselves. Further studies with the use of chimeric peptides indicate that the amino terminal amino acid leucine of N-glycophorin A is a primary determinant of the N antigen, whereas the amino terminal serine of M-glycophorin A is a primary determinant for the M antigen.

[One-stage flap reconstruction of mandibular defects]

Reconstruction of mandibular defects following severe trauma or resection for malignancy presents a challenge. The mandibular shape and the close relationship of the bone to intra- and extra-oral soft tissues, make surgical procedures difficult. Reconstruction has to correct the bony and soft tissue defects, preserve mandibular functions (mastication, speech and swallowing), and allow the patient to wear dentures and to present an esthetic appearance. Techniques used for mandibular reconstruction have included implants of synthetic materials or rebuilding with autogenous bone grafts, and require a well-vascularized recipient bed. We used the free osteocutaneous scapular and iliac flap techniques, which avoid the disadvantages of local flaps and grafts. They were used in 3 patients after mandibular resection for fibrous dysplasia, osteosarcoma, and squamous cell carcinoma of the oral mucosa invading the mandible, respectively.

Unusual proteolysis of the protoxin and toxin from Bacillus thuringiensis. Structural implications

Trypsin is shown to generate an insecticidal toxin from the 130-kDa protoxin of Bacillus thuringiensis subsp. kurstaki HD-73 by an unusual proteolytic process. Seven specific cleavages are shown to occur in an ordered sequence starting at the C-terminus of the protoxin and proceeding toward the N-terminal region. At each step, C-terminal fragments of approximately 10 kDa are produced and rapidly proteolyzed to small peptides. The sequential proteolysis ends with a 67-kDa toxin which is resistant to further proteolysis. However, the toxin could be specifically split into two fragments by proteinases as it unfolded under denaturing conditions. Papain cleaved the toxin at glycine 327 to give a 34.5-kDa N-terminal fragment and a 32.3-kDa C-terminal fragment. Similar fragments could be generated by elastase and trypsin. The N-terminal fragment corresponds to the conserved N-terminal domain predicted from the gene-deduced sequence analysis of toxins from various subspecies of B. thuringiensis, and the C-terminal fragment is the predicted hypervariable sequence domain. A double-peaked transition was observed for the toxin by differential scanning calorimetry, consistent with two or more independent folding domains. It is concluded that the N- and C-terminal regions of the protoxin are two multidomain regions which give unique structural and biological properties to the molecule.

Characterization of the cysteine residues and disulphide linkages in the protein crystal of Bacillus thuringiensis

Bacillus thuringiensis produces a 130-140 kDa insecticidal protein in the form of a bipyramidal crystal. The protein in the crystals from the subspecies kurstaki HD-1 and entomocidus was found to contain 16-18 cysteine residues per molecule, present primarily in the disulphide form as cystine. Evidence that all the cysteine residues form symmetrical interchain disulphide linkages in the protein crystal was obtained from the following results: (i) the disulphide diagonal procedure [Brown & Hartley (1966) Biochem. J. 101, 214-228] gave only unpaired cysteic acid peptides in diagonal maps; (ii) the disulphide bridges were shown to be labile in dilute alkali and the crystal protein could be released quantitatively with 1 mM-2-mercaptoethanol; (iii) the thiol groups of the released crystal protein were shown by competitive labelling [Kaplan, Stevenson & Hartley (1971) Biochem. J. 124, 289-299] to have the same chemical properties as exposed groups on the surface of the protein; (iv) the thiol groups in the released crystal protein reacted quantitatively with iodoacetate or iodoacetamide. The finding that all the disulphide linkages in the protein crystal are interchain and symmetrical accounts for its alkali-lability and for the high degree of conservation in the primary structure of the cystine-containing regions of the protein from various subspecies.

Low-dose methotrexate compared with auranofin in adult rheumatoid arthritis. A thirty-six-week, double-blind trial

Weekly treatment with low-dose oral methotrexate (MTX) was compared with daily auranofin (AUR) treatment in a 36-week double-blind, randomized, multicenter study of 281 patients with active, adult-onset rheumatoid arthritis. Both treatment groups showed significant improvement by the usual measures of clinical efficacy. The response with MTX occurred earlier and was consistently greater than that with AUR. An intent-to-treat analysis showed significantly greater improvement (P less than 0.01) with MTX for painful and swollen joint counts and physician and patient global assessments of disease activity. Adverse reactions were reported more frequently in the AUR group, and more AUR-treated patients were withdrawn from the study because of toxicity. MTX was thus more effective and better tolerated than AUR in this study.

Multifactorial facial pain--differential diagnosis: a case report

A multidisciplinary algology team was formed to facilitate the diagnosis and treatment of complex head and neck pain disorders. The standard patient evaluation includes a history and physical, surface electromyography, Minnesota Multi-phasic Personality Inventory (MMPI), brief psychiatric interview, dental/occlusal analysis, a postural/musculoskeletal examination; and necessary diagnostic imaging. Clinicians meet in conference after each clinic session. Organic and psychiatric findings are compiled and a differential diagnosis is made. Treatment recommendations are outlined and a review of the evaluation and the therapeutic plan are forwarded to the referring doctor. A typical conference discussion is presented here.

Secondary structure of the entomocidal toxin from Bacillus thuringiensis subsp. kurstaki HD-73

The secondary structure of the toxin from Bacillus thuringiensis subsp. kurstaki (Btk) HD-73 was estimated by Raman, infrared, and circular dichroism spectroscopy, and by predictive methods. Circular dichroism and infrared spectroscopy gave an estimate of 33-40% alpha-helix, whereas Raman and predictive methods gave approximately 20%. Raman and circular dichroism spectra, as well as predictive methods, indicated that the toxin contains 32-40% beta-sheet structure, whereas infrared spectroscopy gave a slightly lower estimate. Thus, all of these approaches are in agreement that the native conformation of Btk HD-73 toxin is highly folded and contains considerable amounts of both alpha-helical and beta-sheet structures. No significant differences were detected in the secondary structure of the toxin either in solution or as a hydrated pellet.

Binding of glucagon to lipid bilayers

At physiological pH and temperature, glucagon binds to liposomes composed of egg phosphatidylcholine and cholesterol (2:1 mol/mol) in a highly specific manner. The chemical reactivities of the functional groups were determined over the concentration range of 1.0 X 10(-6)-3.0 X 10(-8) M by the method of competitive labelling with 1-fluoro-2,4-dinitrobenzene as the labelling reagent. At concentrations above 3 X 10(-7) M, the amino terminal histidine and the two tyrosine residues showed a marked decrease in reactivity in the presence of liposomes, but the reactivity of the Lys-12 N epsilon-amino group was unaltered. At lower concentrations the Lys-12 reactivity also decreased markedly, owing to a change in the environment of this group. These results indicated that two different forms of glucagon existed over the concentration range studied. Both in the absence and presence of liposomes the Lys-12 N epsilon-amino groups showed a transition in reactivity at 1.8 X 10(-7) M. In the presence of liposomes the other functional groups also showed a transition in reactivity at 2 X 10(-7) M but the change was much smaller. The pattern of reactivities were consistent with the X-ray crystallographic structure of the type 2 glucagon trimer being the predominant species at 10(-6) M, with free monomeric glucagon occurring at 3 X 10(-8) M. A trimerization constant of 4 X 10(13) M-2 at pH 7.5 and 37 degrees C was determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Neck contracture as a rare complication of cervical soft tissue expansion

An unusual complication using an inflatable silicon implant for removing postburn scarred tissue of the neck and face is described. The appearance of a fibrotic band along the inflating tube caused neck contracture. The purpose of this article is to present this uncommon complication and to emphasize the technical error when using the tissue expander in the neck region.

Chemical properties of the histidine residue of secretin: evidence for a specific intramolecular interaction

Secretin has a single histidine residue located at the amino terminus which plays a crucial role in its biological activity. The chemical properties, viz. pK and reactivity, of the alpha-amino and imidazole groups of this residue were determined at a secretin concentration of 10(-6) M in 0.1 M KCl at 37 degrees C. Competitive labelling using tritiated 1-fluoro-2,4-dinitrobenzene (DNP-F) as the labelling reagent was the experimental approach employed. The alpha-amino group was found to have a pK value of 8.83 and a reactivity 5-times that of the alpha-amino group in the model compound, histidylglycine. For the imidazole function a pK value of 8.24 and a reactivity 26-times that of the imidazole function in histidylglycine was found. Both these groups in secretin had pK values which were shifted one pK unit higher than in histidylglycine, but like the model compound the reactivity of the imidazole function was still linked to the state of ionization of the alpha-amino group. These observations are interpreted as evidence for the existence of a major conformational state in dilute aqueous solution in which the amino-terminal histidine of secretion is interacting with a negatively charged carboxyl group.

Isolation of carboxyl-terminal peptides from proteins by diagonal electrophoresis: application to the entomocidal toxin from Bacillus thuringiensis

A procedure for the selective isolation of the C-terminal peptides from enzymatic digests of proteins is described. The methodology is based on the diagonal electrophoretic procedure described by R. G. Duggleby and H. Kaplan (1975) Anal. Biochem. 65, 346-354). The carboxyl groups in the protein are amidated with [14C]-methylamine followed by enzymatic digestion. Since only the C-terminal peptides lack a free carboxyl group, these peptides will lie on a diagonal line of a two-dimensional electrophoretogram run at pH 2.1 and 4.4. The diagonal line is delineated by autoradiography using [14C]taurine (net charge = 0 at pH 2.1 and 4.4) and [14C]choline (net charge = +1 at pH 2.1 and 4.4). Radioactive C-terminal peptides lie between these markers and can be directly excised for analysis. This procedure permits the detection and selective isolation of C-terminal peptides with minimal losses. The procedure was applied to the test proteins alpha-chymotrypsin and ribonuclease A. It was used to determine the C-terminus of the Bacillus thuringiensis toxin generated by tryptic cleavage of the protoxin.

[Early microsurgical reconstruction of extremities with free microvascular flaps]

The key to successful reconstruction of the extremities after complex trauma is often adequate soft tissue cover of the injured area. In the past, when surgical debridement of wounds was too extensive, or it exposed vital structures such as blood vessels, nerves, tendons or bones, the limb either had to be amputated or reconstructed in multiple surgical procedures. The use of free microvascular flaps in the immediate postinjury period allows single stage reconstruction of wounds including exposed vital tissues. It promotes limb salvage and shortens recovery time after severe trauma. 4 patients with severe complex trauma of the extremities underwent reconstruction with immediate free microvascular flaps, which included latissimus dorsi and rectus abdominis muscle and free scapular flaps. The surgical protocol included debridement of wounds on arrival with primary fixation of fractures and additional debridement procedures in the first week until the wound was stable. Then final fixation of fractures was performed and the wound was covered by a free microvascular flap. With this technique, single stage reconstruction is possible in most cases, with improvement in function and cosmetic outcome, multiple operations are avoided and the recovery period is shortened.

Facile preparation and characterization of the toxin from Bacillus thuringiensis var. kurstaki

We report a simple three-step method of generating a homogeneous toxic fragment (toxin) in high yield from B. thuringiensis var. kurstaki. Purified crystals were digested with trypsin at pH 10.5, followed by (NH4)2SO4 precipitation and dialysis. For the HD73 strain the preparation is toxic to eastern-spruce-budworm (Choristoneura fuminiferana) larvae. It gives a single 66 kDa band on polyacrylamide-gel electrophoresis and a single band with an isoelectric point of 5.5 on an isoelectric-focusing gel. A single isoleucine N-terminus was detected, and the first 20 amino acids were found to be identical with those predicted from the gene nucleotide sequence. A single lysine C-terminus was detected, and the amino acid composition was in excellent agreement with tryptic cleavages at arginine-28 and lysine-623 of the protoxin. Raman spectroscopic analysis gave values of 20% alpha-helix, 35% beta-sheet and 45% unordered structure. The resistance of the toxin to most proteinases and its susceptibility to proteolysis by papain and Pronases indicates a compact multidomain structure.

Euthyroid hyperthyroxinaemia due to endogenous antibodies to thyroxine and tri-iodothyronine. A case report

A case of euthyroid hyperthyroxinaemia caused by auto-antibodies to thyroxine and tri-iodothyronine is presented. Gel filtration chromatography of the patient's serum showed increased binding of radio-labelled thyroxine analogue to a macromolecular component, which migrated in the gammaglobulin region on electrophoresis. Precipitation by protein A confirmed that this was an immunoglobulin. The importance of recognising this condition so that inappropriate therapy can be avoided is stressed.

Design and implementation of a biomedical image database (BDIM)

We developed a biomedical image database (BDIM) which proposes a standardized representation of value arrays such as images and curves, and of their associated parameters, independently of their acquisition mode to make their transmission and processing easier. It includes three kinds of interactions, oriented to the users. The network concept was kept as a constraint to incorporate the BDIM in a distributed structure and we maintained compatibility with the ACR/NEMA communication protocol. The management of arrays and their associated parameters includes two distinct bases of objects, linked together via a gateway. The first one manages arrays according to their storage mode: long term storage on optionally on-line mass storage devices, and, for consultations, partial copies of long term stored arrays on hard disk. The second one manages the associated parameters and the gateway by means of the relational DBMS ORACLE. Parameters are grouped into relations. Some of them are in agreement with groups defined by the ACR/NEMA. The other relations describe objects resulting from processed initial objects. These new objects are not described by the ACR/NEMA but they can be inserted as shadow groups of ACR/NEMA description. The relations describing the storage and their pathname constitute the gateway. ORACLE distributed tools and the two-level storage technique will allow the integration of the BDIM into a distributed structure, Queries and array (alone or in sequences) retrieval module has access to the relations via a level in which a dictionary managed by ORACLE is included. This dictionary translates ACR/NEMA objects into objects that can be handled by the DBMS.(ABSTRACT TRUNCATED AT 250 WORDS)

Microcomputer analyses of clinical ERG, EOG, and other tests of retinal function

The electroretinogram (ERG) and electro-oculogram (EOG) are two of the most frequently used visual electrodiagnostic tests of retinal function. The ERG and EOG are easily measured, but there are many engineering difficulties in processing their signal data because the response amplitudes are relatively small, and the relevant signals are buried in electromagnetic and biologic noise. These tests tend to be time consuming, so they lend themselves to automatic control. This article describes the engineering designs relative to a microprocessor-based electrophysiologic laboratory at Emory University Clinic to perform ERG, EOG, and other clinical tests of retinal function. A comparable system that offered both the ability to accept data from a variety of transducers and the flexibility to permit all of the planned testing protocols was not available from any commercial source.