Role of maintenance sucralfate in prevention of duodenal ulcer recurrence

Fifty-nine patients who had duodenal ulcers that were healed following sucralfate administration in a dose of 1 g four times a day were randomly entered into a double-blind, placebo-controlled, 12-month maintenance study to determine whether sucralfate 1 g twice daily prevents recurrence of duodenal ulceration. Patients were assessed endoscopically at four, eight, and 12 months after healing or earlier if clinical relapse occurred. Of the original 59 patients, 53 showed healing with six weeks of therapy, and the remaining six patients required 10 weeks of treatment. Nine patients were subsequently lost to follow-up because of non-compliance, leaving 50 patients for the analysis, 24 who received sucralfate and 26 who received placebo. There were 10 ulcer recurrences in the sucralfate group and the ulcers in 14 (58 percent) patients remaining healed at the end of 12 months. In contrast, there were 21 recurrences in the placebo group with the ulcers in five patients (19 percent) remaining healed at 12 months. Patients who received placebo experienced recurrence more quickly than those who received sucralfate and there was no difference between the two groups in terms of symptomatic and asymptomatic recurrence. There was no alteration in serum aluminium and phosphate levels throughout the study. Smoking seemed to have no adverse effect on recurrence once initial healing had been achieved. Sucralfate is, therefore, an effective and safe maintenance treatment for duodenal ulcer disease.

Metabolism of C4 and linkage analysis in a kindred with hereditary incomplete C4 deficiency

We studied a kindred in which C4 deficiency had been discovered. Unlike families with total absence of C4, in this kindred C4 deficiency was found to be incomplete, autosomal dominant, not caused by null alleles, and not associated with a high incidence of systemic lupus erythematosus. The deficient state was caused by hyposynthesis of C4, not by hypercatabolism. The locus for incomplete C4 deficiency was not closely linked to the major histocompatibility complex. The abnormal autosomal dominant allele is, apparently, rare, and how it causes decreased synthesis of C4 is unknown.

The effect of protein deficiency on systemic release of rat mucosal mast cell protease II during Nippostrongylus brasiliensis infection and following systemic anaphylaxis

Serum rat mucosal mast cell protease II (RMCPII) was measured in protein-deficient rats to assess mucosal mast cell (MMC) activation during primary infection with the nematode, Nippostrongylus brasiliensis, and during systemic anaphylaxis produced by Nippostrongylus antigen in immune animals. In the first study, serum RMCPII increased 4-fold by day 15 after infection. By day 20, serum RMCPII continued to rise in protein-deficient animals, but decreased in nutritionally normal animals. This was associated with impaired worm rejection in protein-deficient rats. During systemic anaphylaxis, serum RMCPII was elevated in three groups of protein-deficient rats on 6%, 8% and 10% low protein diets and in nutritionally normal rats. All protein-deficient rats exhibited 3 to 7-fold less mucosal permeability of the small intestine to Evan's blue dye injected intravenously compared to nutritionally normal animals following anaphylactic stimulation. These results demonstrated that MMC are activated during infection in protein deficiency, and suggest that reduced MMC function does not explain delay in worm expulsion. Impaired mucosal anaphylaxis in protein deficiency could not be attributed to a failure of MMC response.

Prevention of duodenal ulcer occurrence. Double-blind comparison of ranitidine and cimetidine

We compared ranitidine and cimetidine in maintenance therapy to prevent duodenal ulcer recurrence over a period of 24 months. Endoscopic examination at the end of 12 months showed that the ulcers of 26 of 31 patients (84%) on ranitidine in a dose of 150 mg remained healed and of 10 of 13 (77%) patients on cimetidine in a dose of 400 mg at night remained healed. Thirty-four patients continued in an open evaluation of ranitidine in a dose of 150 mg at night for a further 12-month period, and during this time there were four further recurrences. Life table estimates of duodenal ulcer recurrence during the 2-year period showed no significant difference between the two forms of treatment.

Molecular basis for the deficiency of complement 1 inhibitor in type I hereditary angioneurotic edema

Hereditary angioneurotic edema (HANE) results from deficiency of complement 1 inhibitor (C1 INH). In type I HANE, C1 INH is present in serum at levels 5-30% of normals. Using cultured monocytes and biosynthetic labeling of proteins, C1 INH was detected in supernatants of cells from HANE patients at levels 20% of those detected in normals. The intracellular reduction of C1 INH in patients' monocytes approached 50%. The study of C1 INH messenger RNA (mRNA) by Northern blot analysis indicated that in HANE patients' monocytes a message of normal size is present at about half the concentration of that from normal cells. One of the patients analyzed showed the presence of a genetically inherited abnormal mRNA (1.9 kb) in addition to the normal mRNA (2.1 kb). Southern blot analysis of DNA from peripheral blood leukocytes did not show any difference in quantity or in sizes of endonuclease restriction fragments between patients and normals. The defect(s), therefore, in type I HANE is pretranslational, but is not due to a deletion or to a major chromosomal rearrangement.

The effect of methionine and protein deficiency in delaying expulsion of Nippostrongylus brasiliensis in the rat

Three protein-deficient diets containing 5%, 6%, or 7% casein, with and without 0.3% methionine supplementation, were fed to Wistar rats from weaning for 6 wk. Animals were infected subcutaneously with 1500 larvae of Nippostrongylus brasiliensis and killed after 14 days when nutritionally normal animals have expelled more than 97% of the worm burden. There was a delay in worm expulsion that was related to both the protein content (p = 0.0006) and to methionine content (p less than 0.0001). Methionine supplementation significantly reduced the worm burden in animals fed the 7% protein diet from a geometric mean of 32.4 to 5.2 (p = 0.0408) and in rats fed the 6% protein diet from a mean of 162 to 8.1 (p = 0.0002) but had no effect in rats on the 5% casein diet. Thus, addition of methionine overcame the adverse effect of protein deficiency in these less severely affected groups.

Blood loss during Nippostrongylus brasiliensis infection in the rat

Faecal blood loss was measured during Nippostrongylus brasiliensis infection in the DA rat using 51Cr-labelled red blood cells (r.b.c.s). In an initial study, faecal blood loss was measured on day 7 of primary infection with 3000 larvae administered subcutaneously (s.c.), and found to be 0.03 ml/24 h in uninfected animals and 0.14 ml/24 h in infected animals. In a further experiment, blood loss was measured on the day before infection and for 13 days after primary s.c. infection with 5000 larvae. Faecal blood loss was 0.05 ml/24 h or less until day 3, began to rise from day 5, reached a peak of 0.51 ml/24 h on day 8, and fell until day 13. This was closely associated with the rise and fall of the pooled faecal egg count. Direct worm count confirmed a high worm burden on day 7 and expulsion by day 14. The effect of the worm burden on the haemoglobin concentration (Hb) was measured in a further experiment and showed a fall in Hb with a mean worm burden of 726 compared to that of 47 or 284 worms. The study concluded that there is minimal background blood loss in uninfected rats but that infection with N. brasiliensis is a cause of intestinal blood loss and this is associated with a fall in Hb concentration that is dependent on the worm burden.

Purification and chemical composition of gpL115, the human lymphocyte surface sialoglycoprotein that is defective in Wiskott-Aldrich syndrome

gpL115, the surface sialoglycoprotein that is defective in lymphocytes of Wiskott-Aldrich syndrome patients has been purified from large scale cultures of the lymphoblastoid line CEM. The purification entails cell lysis and solubilization of gpL115 with the detergent Nonidet P-40, sequential affinity chromatography on lentil lectin-Sepharose, wheat germ lectin-Sepharose, and, after treatment with sialidase, on peanut lectin-Sepharose. Sepharose CL-6B gel filtration removes residual protein contaminants and transfers asialo-gpL115 from Nonidet P-40-containing to sodium dodecyl sulfate-containing buffer. The yield, 1300 micrograms of homogeneous protein/10(11) cells, represents greater than 60% recovery. The amino acid composition of gpL115 has several atypical features including low lysine content, high proline content, and very high content of hydroxyamino acids (12.5 residues of serine and 12.5 residues of threonine/100 amino acids). Total carbohydrate content of gpL115 is very high, i.e. 52% for the asialo-molecule. The major carbohydrate residues of asialo-gpL115 are galactose and N-acetylgalactosamine in approximately equimolar amounts (25 and 22 residues/100 amino acids, respectively) plus severalfold lower amounts of N-acetylglucosamine, fucose, and mannose.

Human inhibitor of the first component of complement, C1: characterization of cDNA clones and localization of the gene to chromosome 11

C1 inhibitor is a heavily glycosylated plasma protein that regulates the activity of the first component of complement (C1) by inactivation of the serine protease subcomponents, C1r and C1s. C1 inhibitor cDNA clones have been isolated, and one of these (pC1INH1, 950 base pairs) has been partially sequenced. Sequence analysis demonstrates that the C1 inhibitor is a member of the serpin "superfamily" of protease inhibitors. In the region sequenced, C1 inhibitor has 22% identity with antithrombin III, 26% with alpha 1-antitrypsin and alpha 1-antichymotrypsin, and 18% with human angiotensinogen. C1 inhibitor has a larger amino-terminal extension than do the other plasma protease inhibitors. In addition, inspection of residues that are invariant among the other protease inhibitors shows that C1 inhibitor differs at 14 of 41 of these positions. Thus, it appears that C1 inhibitor diverged from the group relatively early in evolution, although probably after the divergence of angiotensinogen. Southern blot analysis of BamHI-digested DNA from normal individuals and from rodent-human somatic cell hybrid cell lines (that contain a limited but varied human chromosome complement) was used to localize the human C1 inhibitor gene to chromosome 11.

Ultrastructure and composition of bovine conglutinin

Conglutinin binds in a Ca2+-dependent manner to the carbohydrate portion of zymosan and cell-bound iC3b (complement subcomponent C3b cleaved by Factor I in the presence of factor H) similarly to lectin-like proteins that participate in the clearance of plasma glycoproteins. This carbohydrate-binding protein has been found to include both collagenous and non-collagenous domains. Electron micrographs of bovine conglutinin are presented in which conglutinin appears as a tetramer of four 'lollipop' structures emanating from a central hub. The stem region, linking each head to the central hub, is quite stiff, whereas the hub-stem junction is a flexible hinge. From electron micrographs of a pepsin digest of conglutinin, the linkage region is identified as the collagenous portion of the macromolecule. Conglutinin is a multimer of a single polypeptide chain. From sedimentation equilibria of unreduced as compared with reduced and alkylated conglutinin, there are determined to be three disulphide-linked chains. These data, combined with information on the subunit polypeptide of conglutinin, suggest a model for conglutinin in which four disulphide-linked trimers are associated via the N-termini to form the intact macromolecule as viewed in the electron microscope. The ultrastructure of conglutinin appears ideally suited to its lectin-like function.

Acoustic brainstem responses for clinical use: the effect of attention

The acoustic brainstem response (ABR) is generally thought to be unaffected by variation in attention; however, recent papers suggest that during visual distraction of the subject wave Nv may be delayed. We have examined the ABRs of 22 normal subjects in states of auditory attention and visual distraction, using routine clinical testing procedures. We have shown that under these conditions altered attention states have no demonstrable effect on the latency of wave Nv.

Acoustic brainstem responses for clinical use: a comparison of pure tone stimuli with wide band clicks

The acoustic brainstem response (ABR) in clinical use is generally elicited by a wide band click stimulus. This gives a well-synchronized response detectable at low sound intensities, but requires tedious biological recalibration which could be largely eliminated by the use of pure tone pip stimuli. We have therefore assessed ABRs in response to pure tone pips at 2 KHz and 4 KHz. This has shown that these tone pips elicit a much poorer response than clicks, having thresholds which are both significantly higher, and more widely distributed. We therefore conclude that wide band clicks remain the most satisfactory stimulus for clinical use.

Focus on rehabilitation in the acute care setting: the role of the neuro clinical nurse specialist

Establishment of an early rehabilitation program for patients with neurological/neurosurgical illness or injury is the focus of this article. The Neuroscience Clinical Nurse Specialist (NCNS) is identified as having a major responsibility in initiating early rehabilitation in the acute care setting. Development of the rehabilitation program is discussed through the NCNS's roles as educator, clinician, consultant, and researcher. Implementation of the rehabilitation program emphasizes the use of the nursing process, the role of the staff nurse, active patient and family participation, and use of the interdisciplinary team approach. General concepts rather than specific practices are used in order to present an overview of the role.

Reversible nutritional myopathy with myotonia in the protein-deficient rat given methionine

Rats fed a protein-deficient synthetic diet developed hind limb weakness caused by a myopathy with myotonic features on electromyography. Deficiency of vitamin E and selenium, known causes of nutritional myopathy, were excluded. Methionine supplementation of the diet reversed the clinical signs of weakness within 12 h.

A synthetic nonapeptide corresponding to the NH2-terminal sequence of C3d-K causes leukocytosis in rabbits

Numerous biologically active fragments have been described that are derived from the C3 molecule. Recently, a polypeptide (Mr 41,000) generated from the alpha chain of human iC3b by limited proteolysis with plasma kallikrein was shown to exhibit several biological functions. This C3-derived cleavage product, C3d-K, suppresses mitogen- and antigen-induced proliferation of human T-lymphocytes and induces leukocytosis in rabbits. We have identified and synthesized a portion of C3d-K that is associated with the leukocytosis phenomenon. A nonapeptide corresponding to the amino-terminal nine residues of C3d-K was synthesized using conventional Merrifield solid-phase peptide chemistry; the structure of this peptide is Thr-Leu-Asp-Pro-Glu-Arg-Leu-Gly-Arg (TLDPERLGR). At a final concentration of 4 X 10(-6) M, both the nonapeptide and the des-Arg octapeptide (TLDPERLG) were capable of inducing leukocytosis in rabbits. Additionally, both peptides enhance vascular permeability when injected in guinea pig skin. These activities are similar to those previously attributed to a C3 fragment identified as C3e by Ghebrehiwet and Müller-Eberhard (Ghebrehiwet, B., and Müller-Eberhard, H.J. (1979) J. Immunol. 123, 616-621). We conclude that the nonapeptide TLDPERLGR represents the active center of the C3-derived leukocytosis factors C3e and C3d-K. This active synthetic analogue of C3d-K should prove valuable in elucidating the mechanism of action for complement-dependent leukocyte mobilization in vivo.

The histopathological changes in the thymus gland in the acquired immune deficiency syndrome

Histologic study of the thymus glands from patients who have died of AIDS reveals changes consistent with an organ-specific immune complex attack by polyclonal immunoglobulins directed against the thymic epithelial cells, Hassall's corpuscles, and certain subsets of thymocytes. This results in marked architectural alteration: there is eventual disappearance of the corpuscles, the epithelial cells become spindled with pyknotic nuclei, there is thymocyte depletion and patchy fibrosis, and there is loss of the normal corticomedullary demarcation. These changes are characteristic and are not found in the normal aging process of the thymus gland. The blood levels of thymic peptides are abnormal. There appears to be specific immunoglobulins directed against thymic epithelial cells, Hassall's corpuscles, and certain subsets of T lymphocytes. The end result appears to be both a histologic and functional thymic disorder. If this is correct, then appropriate therapy for AIDS may be thymic peptide replacement or even thymic transplantation.

Serum pancreatic isoamylase estimation by the inhibitor method as a diagnostic test for chronic pancreatitis

The diagnosis of chronic pancreatitis is often difficult to establish and may involve invasive diagnostic procedures. Serum pancreatic isoamylase has been estimated by the inhibitor method in controls and in 38 patients with known chronic pancreatitis in order to evaluate its use as a diagnostic test. The mean pancreatic isoamylase in those with chronic pancreatitis (68 +/- 77 IU/l) was significantly lower (p less than 0.005) than in controls (113 +/- 60 IU/l). The diagnostic sensitivity of pancreatic isoamylase was 50% (compared to total amylase 9%) and had a specificity of 95%. Stimulation tests with cholecystokinin and secretin failed to increase the sensitivity of the test. A low value of pancreatic isoamylase strongly supports a diagnosis of chronic pancreatitis and may obviate the need for further investigation.

Bovine conglutinin is a collagen-like protein

Conglutinin is a bovine plasma protein which is relatively large and asymmetric with elevated contents of glycine and, to some extent, proline. Although its physiologic function is unknown, conglutinin is known to bind, in the presence of calcium, to yeast cell walls and to the solid-phase-inactivated third component of complement. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, isolated conglutinin appeared to consist of a single polypeptide chain (Mr 48 000). Unreduced conglutinin consisted of a single stained band with an apparent molecular weight of approximately 300 000. Cross-linking experiments with glutaraldehyde and dimethyl suberimidate suggested that this Mr 300 000 molecule consists of six of the disulfide-linked polypeptide chains. Amino acid composition revealed hydroxylysine and hydroxyproline together with elevated glycine and proline contents. Digestion of reduced, alkylated conglutinin with bacterial collagenase resulted in formation of a precipitate which consisted of an Mr 24 000 peptide which was digested to Mr 21 000 with large quantities of collagenase. These peptides contained less glycine, proline, hydroxylysine, and hydroxyproline than did the intact protein. The supernatant from this digestion mixture was, however, enriched in these four amino acids, with glycine making up nearly one-third of the total. Prolonged digestion with pepsin at 37 degrees C resulted in an Mr 20 000 peptide which was enriched in glycine, proline, hydroxyproline, and hydroxylysine. Amino-terminal sequence analysis showed that the glycine-X-Y repeating sequence begins at residue 26.(ABSTRACT TRUNCATED AT 250 WORDS)

Physiologic inactivation of fluid phase C3b: isolation and structural analysis of C3c, C3d,g (alpha 2D), and C3g

The fragments that result from the inactivation of C3b have not been completely characterized. Initial inactivation is catalyzed by the protease factor I, which, in the presence of its cofactor (factor H), cleaves two peptide bonds in the alpha'-chain of C3b. This results in the release of a small peptide (C3f, Mr 3000) from iC3b, which consists of the C3 beta chain covalently bonded to two alpha'-chain-derived peptides (Mr 68,000 and Mr 43,000). Surface-bound iC3b is cleaved at a third site by factor I to produce C3c and C3d,g (or alpha 2D). The factor I cofactor for this cleavage is the C3b receptor that is present on erythrocyte and leukocyte membranes. This report describes the isolation and initial structural characterization of C3c and C3d,g generated in whole blood after complement activation with cobra venom factor. These fragments were compared with the C3 fragments isolated from the serum and plasma of a patient with complement activation in vivo. The fragments were isolated with two solid phase monoclonal antibodies, one of which recognizes a determinant on C3g (clone 9) and one of which recognizes a determinant on C3c (clone 4). C3c isolated from normal blood showed three polypeptides that had apparent m.w. of 75,000, 43,000, and 27,000. The C3d,g consisted of a single polypeptide chain with a m.w. of 40,000. Amino terminal sequence analysis showed that the Mr 27,000 peptide from C3c is derived from the amino terminal portion of the alpha'-chain of C3b, whereas the Mr 43,000 peptide is derived from the carboxy terminus of the same chain. Amino terminal sequence analysis showed also that C3g is derived from the amino terminus of C3d,g. The C3 fragments isolated from a patient with partial lipodystrophy, nephritic factor activity, low serum C3 levels, and circulating C3 cleavage products showed a more complicated pattern on SDS-PAGE. The fragment isolated with clone 9 had an apparent m.w. of 40,000, identical to C3d,g generated in vitro, and it had the same amino terminal sequence as C3d,g generated in vitro. The eluate from insolubilized clone 4, however, showed prominent bands with Mr of 75,000, 56,000, 43,000, and 27,000, together with a triple-banded pattern at 68,000 and a minor band at 80,000. This eluate thus appears to contain C3c, and iC3b or an iC3b-like product. The origin of the Mr 56,000 and Mr 80,000 peptides have not yet been determined. These studies, with previous data, definitively order the C3c and C3d,g peptides in the alpha-chain of C3.(ABSTRACT TRUNCATED AT 400 WORDS)

Physiologic inactivation of fluid phase C3b: isolation and structural analysis of C3c, C3d,g (alpha 2D), and C3g

The fragments that result from the inactivation of C3b have not been completely characterized. Initial inactivation is catalyzed by the protease factor I, which, in the presence of its cofactor (factor H), cleaves two peptide bonds in the alpha'-chain of C3b. This results in the release of a small peptide (C3f, Mr 3000) from iC3b, which consists of the C3 beta chain covalently bonded to two alpha'-chain-derived peptides (Mr 68,000 and Mr 43,000). Surface-bound iC3b is cleaved at a third site by factor I to produce C3c and C3d,g (or alpha 2D). The factor I cofactor for this cleavage is the C3b receptor that is present on erythrocyte and leukocyte membranes. This report describes the isolation and initial structural characterization of C3c and C3d,g generated in whole blood after complement activation with cobra venom factor. These fragments were compared with the C3 fragments isolated from the serum and plasma of a patient with complement activation in vivo. The fragments were isolated with two solid phase monoclonal antibodies, one of which recognizes a determinant on C3g (clone 9) and one of which recognizes a determinant on C3c (clone 4). C3c isolated from normal blood showed three polypeptides that had apparent m.w. of 75,000, 43,000, and 27,000. The C3d,g consisted of a single polypeptide chain with a m.w. of 40,000. Amino terminal sequence analysis showed that the Mr 27,000 peptide from C3c is derived from the amino terminal portion of the alpha'-chain of C3b, whereas the Mr 43,000 peptide is derived from the carboxy terminus of the same chain. Amino terminal sequence analysis showed also that C3g is derived from the amino terminus of C3d,g. The C3 fragments isolated from a patient with partial lipodystrophy, nephritic factor activity, low serum C3 levels, and circulating C3 cleavage products showed a more complicated pattern on SDS-PAGE. The fragment isolated with clone 9 had an apparent m.w. of 40,000, identical to C3d,g generated in vitro, and it had the same amino terminal sequence as C3d,g generated in vitro. The eluate from insolubilized clone 4, however, showed prominent bands with Mr of 75,000, 56,000, 43,000, and 27,000, together with a triple-banded pattern at 68,000 and a minor band at 80,000. This eluate thus appears to contain C3c, and iC3b or an iC3b-like product. The origin of the Mr 56,000 and Mr 80,000 peptides have not yet been determined. These studies, with previous data, definitively order the C3c and C3d,g peptides in the alpha-chain of C3.(ABSTRACT TRUNCATED AT 400 WORDS)

Cooperative interaction of factor B and other complement components with mononuclear cells in the antibody-independent lysis of xenogeneic erythrocytes

Synergistic cytotoxicity is a term used to describe a cytotoxic system in which xenogeneic erythrocyte target cells are lysed in the presence of nonimmune human mononuclear effector cells and antibody-depleted normal human serum. Neither the mononuclear cells nor the serum alone are cytolytic to the target erythrocytes. Previous studies have shown that the serum activity is not immunoglobulin and is heat-labile, suggesting a similarity to serum complement. In this report, sera deficient in various complement components as well as highly purified single complement components were tested with whole mononuclear cell populations and purified monocytes and lymphocytes to further characterize this cytotoxicity system. Whole mononuclear cell populations failed to mediate target cell lysis in sera deficient in C5 or factor B. However, C3-deficient serum, even in the presence of anti-C3 antibody, supported synergistic cytotoxicity normally. Purified lymphocytes were also normally cytotoxic in C3-deficient serum but failed to lyse targets in sera deficient in C5, C7, C8, or depleted of factor B. Purified monocytes failed to lyse the target cells only in factor B-depleted serum and could lyse the target cells in serum-free medium when purified factor B alone was added. Monocyte-mediated cytotoxicity induced by factor B was inhibited 73-100% by adding lymphocytes back to the purified monocytes. Thus, both lymphocytes and monocytes can serve as effector cells in this form of cytotoxicity but require cooperative interaction with different sets of complement components. In addition, lymphocytes can modulate the monocyte-mediated form of target cell lysis associated with factor B.

A prospective study of persistent diarrhoea

A prospective study was undertaken in 100 patients with diarrhoea to identify the causes and to better define the prevalence of the irritable bowel syndrome (IBS) and to determine if there was a diagnostic symptom complex evident in patients with IBS. A diagnosis of IBS was made in 28 patients and in this group the prevalence of lactase deficiency was found to be 40%. Pain in association with urgency was usual and urgency occurring in the absence of pain was more likely to be found in association with an organic colonic lesion. The two most important symptoms which distinguish IBS from other causes were blood in the motions and weight loss. Giardia lamblia were found in nine patients and 15 patients responded to an empirical course of either metronidazole or tinidazole, without a positive diagnosis of giardiasis being made. Fourteen patients had inflammatory bowel disease and a variety of drugs were responsible for diarrhoea in 10% of patients. Sigmoidoscopy and small bowel biopsy were the most valuable diagnostic investigations.

Delayed expulsion of the nematode Nippostrongylus brasiliensis from rats on a low protein diet: the role of a bone marrow derived component

Rats on a low protein diet, containing 10% casein as the only source of protein, have an impaired capacity to expel primary infections with the nematode Nippostrongylus brasiliensis and remain susceptible to reinfection. In the present study, the transfer of syngeneic bone marrow cells to rats on a low protein diet reconstituted the expulsion mechanism allowing parasite rejection to occur at the same rate as rats on a sufficient diet. Serum transfer, on the other hand, did not significantly alter the rate of worm expulsion. These results demonstrate that a bone marrow derived component plays an important role in the impaired immunity of rats fed a low protein diet.

EMG biofeedback in patients with motor disorders: an aid for co-ordinating activity in antagonistic muscle groups

A computer program was developed to analyse the relative amount of EMG activity in an agonist-antagonist pair of muscles while subjects performed voluntary flexion-extension movements at the wrist to track a visual target. The data were presented to the subjects in the form of a vector display, the angle and length of which was determined from calculation of EMG power in the two muscles. This new approach to EMG biofeedback was evaluated in two hemiplegic patients and three patients with cerebellar incoordination. Over a training period of several weeks, all the subjects were able to modify the pattern of EMG activity in the muscles to reduce the amount of inappropriate coactivation of flexors and extensors and to produce more sustained and regular activation of individual muscle groups.

Active site amino acid sequence of human factor D

Factor D was isolated from human plasma by chromatography on CM-Sephadex C50, Sephadex G-75, and hydroxylapatite. Digestion of reduced, S-carboxymethylated factor D with cyanogen bromide resulted in three peptides which were isolated by chromatography on Sephadex G-75 (superfine) equilibrated in 20% formic acid. NH2-Terminal sequences were determined by automated Edman degradation with a Beckman 890C sequencer using a 0.1 M Quadrol program. The smallest peptide (CNBr III) consisted of the NH2-terminal 14 amino acids. The other two peptides had molecular weights of 17,000 (CNBr I) and 7000 (CNBr II). Overlap of the NH2-terminal sequence of factor D with the NH2-terminal sequence of CNBr I established the order of the peptides. The NH2-terminal 53 residues of factor D are somewhat more homologous with the group-specific protease of rat intestine than with other serine proteases. The NH2-terminal sequence of CNBr II revealed the active site serine of factor D. The typical serine protease active site sequence (Gly-Asp-Ser-Gly-Gly-Pro was found at residues 12-17. The region surrounding the active site serine does not appear to be more highly homologous with any one of the other serine proteases. The structural data obtained point out the similarities between factor D and the other proteases. However, complete definition of the degree of relationship between factor D and other proteases will require determination of the remainder of the primary structure.

The effect of iron deficiency, protein deficiency and dexamethasone on infection, re-infection and treatment of Giardia muris in the mouse

The association between nutrient deficiencies, steroid administration, anti-flagellate therapy and giardiasis was examined using the Giardia muris/mouse model. Administration of steroids to BALB/c mice resulted in persisting high levels of infection with G. muris, whereas untreated animals were able to eliminate this parasite. In addition, steroid treatment significantly reduced the efficacy of anti-flagellate therapy. Protein-deficient mice eliminated the parasite at the same rate as mice on an optimum diet and also developed strong acquired resistance to re-infection. A similar pattern was observed in iron-deficient mice, except that the number of parasites that became established during the first 2 weeks of infection was significantly reduced. Thus, there was no evidence of synergism between iron and protein deficiency and infection in this model.

Properdin factor D: effects on thrombin-induced platelet aggregation

Factor D, when preincubated with platelet suspensions, at concentrations as low as 1.2 micrograms/ml, inhibited thrombin-induced platelet aggregation. No inhibition of collagen or arachidonic acid-induced platelet aggregation was found. Inhibition occurred, but to a lesser extent, when thrombin and factor D were added to platelets at the same time. No inhibition occurred when factor D was added after thrombin. Thrombin was able to overcome inhibition by factor D by increasing its concentration. Diisopropyl-phosphorofluoridate-inactivated factor D also inhibited thrombin-induced platelet aggregation so that enzymatic activity of factor D was not required for inhibition. Factor D absorbed with hirudin coupled to Sepharose 6B showed no decrease in inhibitory capacity. 125I-Factor D bound to platelets in a manner suggesting an equilibrium reaction similar to thrombin. At low factor D input, binding was linear, whereas at higher input, binding began to approach saturation. Binding of 125I-labeled thrombin to platelets was inhibited by factor D. Analysis of these data show that factor D does not alter the total number of thrombin molecules which bind to the platelet surface at saturation. However, the dissociation constant for thrombin is altered from 2.78 to 6.90 nM in the presence of factor D (20 micrograms/ml). Factor D is thus a competitive inhibitor of thrombin binding, although the affinity of factor D for the platelet thrombin receptor is much less than that of thrombin. These phenomena occur at physiologic concentrations of factor D. Therefore, factor D may function in vivo as an inhibitor of platelet aggregation.

Neutralization test in influenza: use in individuals without hemagglutination inhibition antibody

In influenza immunization trials, patients who were seronegative by the hemagglutination inhibition test could be divided into two groups according to preimmunization levels of neutralizing (Neut) and neuraminidase inhibition (NI) antibodies. The group with low levels of Neut and NI antibodies usually developed adequate levels of hemagglutination inhibition antibody after one dose of vaccine, and the group with undetectable Neut and NI antibodies did not.

Complement-dependent histaminase release from human granulocytes

The role of particle-bound complement proteins in the induction of noncytotoxic enzyme release from human granulocytes was investigated with the use of sera genetically deficient in complement and highly purified complement components. Release of histaminase, one of two important histamine catabolizing enzymes, and beta-glucuronidase from polymorphonuclear leukocytes was solely dependent on particle-bound C3b (the larger cleavage product of the third component of complement) when fluid-phase complement was excluded. The extent of enzyme release was a function of particle-bound C3b input, was reduced by exposing the particles to C3b inactivator, and was blocked by fluid-phase C3b. Phagocytosis of the C3b-coated particles was not required for enzyme release from neutrophils. In contrast, phagocytosis of "opsonized" particles was required for noncytotoxic release of histaminase and arylsulfatase from eosinophils; other proteins, as well as C3b, were able to opsonize particles for induction of enzyme release from eosinophils. These studies suggest a dual role for complement (particularly C3) in modulating vascular permeability phenomena, i.e., release of vasoactive mediators by the action of C3a and C5a, and release of the corresponding enzymes that inactivate the mediators by C3b.

Nippostrongylus brasiliensis infection in the rat: effect of iron and protein deficiency on the anthelmintic efficacy of mebendazole, pyrantel, piperazine, and levamisole

The benzimidazole anthelmintics mebendazole and fenbendazole have been shown to be much less effective against Nippostrongylus brasiliensis infections in the rat on a combined iron and protein deficient diet. In the present experiments it was shown that the anthelmintic efficacy of mebendazole was significantly impaired in the rat on either an iron deficient or a protein deficient diet. Furthermore, iron and protein deficiency reduced the efficacy of the anthelmintics pyrantel and piperazine but not levamisole. The finding that nutritional deficiencies reduce anthelmintic efficacy may well be relevant to worm eradication programmes in iron deficient and protein calorie malnourished populations.

Suppression of rejection of Nippostrongylus brasiliensis in iron and protein deficient rats: effect of syngeneic lymphocyte transfer

Rejection of Nippostrongylus brasiliensis is impaired in iron and protein deficient rats and this suggests that iron and protein deficiency directly or indirectly suppresses the immune response. The site of the immunological defect in deficient rats was investigated using the technique of cellular transfer of resistance. The functional activity of immune mesenteric lymph node cells obtained from iron and protein deficient donors was not depressed as measured by their capacity to cause parasite rejection in nutritionally sufficient recipients. In contrast, immune lymph node cells obtained from either sufficient or deficient donors did not result in parasite rejection in iron and protein deficient recipients. These results indicate that there is no permanent defect of lymphocyte function in iron and protein deficient rats and suggest that either some other component of the rejection mechanism is defective, or that lymphocyte function is blocked in an iron and protein deficient environment.

Histopathology in giardiasis: a correlation with diarrhoea

There is controversy both in regard to the severity of small bowel mucosal damage attributable to giardiasis and to the causal relationship of these changes to the associated diarrhoea. In this series of 17 consecutive patients with giardiasis, small bowel histology and diarrhoea were independently assessed and compared. Disaccharidase assays were performed in 16 of these patients and a repeat biopsy obtained in seven cases. On histological examination the villous architecture varied from normal to sub-total villous atrophy. When these changes were compared with the severity of diarrhoea, a direct correlation was obtained, the more severe symptoms being associated with the more severe villous changes. Repeat biopsy after treatment demonstrated improvement in the histology which correlated with improvement in diarrhoea. Lactase activity was low in all patients with moderate or severe diarrhoea as well as in some patients with mild diarrhoea, two of whom had normal histology. This series demonstrates the occurrence of a spectrum of mucosal changes in giardiasis and supports the concept that these changes mediate the diarrhoea associated with this gut parasite.

Membranoproliferative glomerulonephritis (MPGN type I) and dense deposit disease (DDD) in children

A review of the histologic findings in 27 patients originally classified as having some form of membranoproliferative glomerulonephritis (MPGN) revealed 13 with MPGN Type I and 14 with dense deposit disease (DDD). In all 14 cases where electron microscopy was performed, the histologic diagnosis was confirmed. In nine cases the diagnosis of DDD was easily made in histologic sections on the basis of ribbon-like, brightly PAS positive thickening of the GBM, without "splitting" and with relatively slight mesangial proliferation. However, in five cases the picture closely resembled MPGN Type I, with hypercellularity, "splitting" and only focal ribbon-like thickening of the GBM, which required oil immersion for recognition. There was no correlation between the serum C3 levels and the morphologic diagnosis: nine (4 MPGN Type I, 5DDD) had persistently low C3 levels, two (1 MPGN Tye I, 1DDD) were normocomplementemic, and in 16, the C3 levels varied. C3 levels increased with time in nearly all patients. The clinical course was similar in patients with MPGN Type I and DDD. Significant correlations between the rate of development of renal failure and sex, age of onset, nephrotic syndrome or therapy could not be made. The five year survival rate was 87%; 12 developed renal insufficiency by five years. Although morphologically distinct, these findings suggest that DDD is clinically indistinguishable from MPGN Type I.

Nippostronglylus brasiliensis infection in the rat: effect of iron and protein deficiency and dexamethasone on the efficacy of benzimidazole anthelmintics

Malnutrition, anaemia, and gut parasites are commonly interrelated. Using the Nippostrongylus brasiliensis-rat model, the effect of iron and protein deficiency on the efficacy of benzimidazole anthelmintics was studied. It was demonstrated that the anthelmintics mebendazole and fenbendazole were significantly less effective in eradicating parasites when animals were deficient in iron and protein. This decreased efficacy of anthelmintics in iron and protein deficiency could not be overcome by intraperitoneal administration of the drug. Since nutritional deficiencies may act via impairment of the immune response, anthelmintic efficacy was determined in adequately nourished rats treated with the immunosuppressive drug dexamethasone. A similar decrease in efficacy of mebendazole was shown when these animals were treated with dexamethasone. Thus it is possible that lowered anthelmintic efficacy in iron and protein deficient animals is mediated by immune deficiency. These findings may be relevant to anthelmintic programmes in malnourished communities.

Biosynthesis of the third component of complement (C3) in vitro by monocytes from both normal and homozygous C3-deficient humans

Human monocytes synthesized the third component of complement (C3) up to 5 wk in vitro. Evidence for net C3 synthesis was based on (a) incorporation of 14C-labeled amino acids into C3 protein, (b) indentity of the allotype of C3 produced in vitro with that of the doner's serum C3, even in the presence of carrier C3 protein of a different allotype; (c) correspondence of electrophoretic mobility, size, and subunit structure of C3 protein produced in vitro with serum C3; (d) inhibition of C3 production with cycloheximide. Monocytes from two unrelated C3-deficient patients were studied under conditions that supported C3 synthesis by normal monocytes. Serum from each of the patients contained less than 1% of the normal C3 concentration, buth their monocytes produced C3 at approximately equal to 25% of the normal rate when studied after 2 wk in vitro. The C3 produced in vitro by monocytes from one of the patients had the molecular weight of normal serum C3 and dissociated appropriately under reducing conditions. Monocytes from C3-deficient patients could not be distinguished from normals on the basis of morphology, rosetting with C3-coated erythrocytes, or rates of C2, and total protein synthesis.