Ganglioside-induced adherence of botulinum and tetanus neurotoxins to adducin

Preincubation of botulinum neurotoxin serotype A, B, or E with ganglioside GT1b was previously found to enhance adherence of botulinum neurotoxin to synapsin I and an approximately 116-kDa bovine brain synaptosomal protein; in contrast, adherence to these two proteins by tetanus neurotoxin required preincubation with GT1b. We have now found that preincubation of the neurotoxins with ganglioside GD3 enhances their adherence to the approximately 116-kDa protein more than that with GT1b. A purified preparation of the water-soluble approximately 116-kDa protein was obtained from bovine brain synaptosomes by preparative column sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis. N-Terminal amino acid sequences were obtained for two tryptic fragments of the approximately 116-kDa protein. These sequences matched with the data bank sequences for beta-adducin, a cytoskeletal protein. The carboxy-terminal tail region of adducin, but not the head region, was adhered to by the neurotoxins. Adherence of the neurotoxin to adducin and synapsin I may facilitate presentation of the neurotoxin to its specific substrate(s).

A new function for adducin. Calcium/calmodulin-regulated capping of the barbed ends of actin filaments

Adducin is a membrane skeleton protein originally described in human erythrocytes that promotes the binding of spectrin to actin and also binds directly to actin and bundles actin filaments. Adducin is associated with regions of cell-cell contact in nonerythroid cells, where it is believed to play a role in regulating the assembly of the spectrin-actin membrane skeleton. In this study we demonstrate a novel function for adducin; it completely blocks elongation and depolymerization at the barbed (fast growing) ends of actin filaments, thus functioning as a barbed end capping protein (Kcap approximately 100 nM). This barbed end capping activity requires the intact adducin molecule and is not provided by the NH2-terminal globular head domains alone nor by the COOH-terminal extended tail domains, which were previously shown to contain the spectrin-actin binding, calmodulin binding, and phosphorylation sites. A novel difference between adducin and other previously described capping proteins is that it is down-regulated by calmodulin in the presence of calcium. The association of stoichiometric amounts of adducin with the short erythrocyte actin filaments in the membrane skeleton indicates that adducin could be the functional barbed end capper in erythrocytes and play a role in restricting actin filament length. Our experiments also suggest novel possibilities for calcium regulation of actin filament assembly by adducin in erythrocytes and at cell-cell contact sites in nonerythroid cells.

Eosinophilia in chronic childhood sinusitis

OBJECTIVES

To quantify eosinophilia in sinus tissues obtained from children with chronic sinusitis and to correlate the degree of eosinophilia with history of asthma, allergy, cystic fibrosis, and preoperative computed tomographic (CT) scans.

DESIGN

Examination of surgical specimens from children who underwent functional endoscopic sinus surgery and controls.

SETTING

Tertiary care medical center.

PATIENTS

Thirty-four children who underwent functional endoscopic sinus surgery for chronic sinusitis refractory to medical treatment were divided into three groups: 13 with asthma, 11 without asthma, and 10 with cystic fibrosis. Normal sphenoid sinus mucosa was also obtained from six adults undergoing transsphenoidal hypophysectomies.

MAIN OUTCOME MEASURES

Number of lamina propria and intraepithelial eosinophils in surgical specimens, allergic status, presence or absence of asthma, and CT scans obtained preoperatively.

RESULTS

There were significantly more lamina propria and intraepithelial eosinophils in the tissue of children with chronic sinusitis compared with normal sphenoid sinus mucosa. More eosinophils were counted in the tissues of patients with asthma and cystic fibrosis compared with patients without concomitant disease, but this did not reach statistical significance. Allergy status did not affect the degree of tissue eosinophilia. Eosinophilia did not correlate with severity of mucosal disease as assessed by CT scans.

CONCLUSIONS

Tissue eosinophilia is a characteristic histologic feature of chronic sinusitis in children, especially those with asthma. The presence of allergy does not predict tissue eosinophilia. Furthermore, the degree of tissue eosinophilia does not correlate with the severity of mucosal thickening seen on CT scans.

Adducin: a physical model with implications for function in assembly of spectrin-actin complexes

Adducin binds to spectrin-actin complexes, promotes association of spectrin with actin, and is subject to regulation by calmodulin as well as protein kinases A and C. Adducin is a heteromer comprised of homologous alpha and beta-subunits with an NH2-terminal protease-resistant head domain, connected by a neck region to a COOH-terminal hydrophilic, protease-sensitive region. This study provides evidence that adducin in solution is a mixture of heterodimers and tetramers. CD spectroscopy of COOH-terminal domains of alpha- and beta-adducin bacterial recombinants provides direct evidence for an unstructured random coil configuration. Cross-linking, proteolysis, and blot-binding experiments suggest a model for the adducin tetramer in which four head domains contact one another to form a globular core with extended interacting alpha- and beta-adducin tails. The site for binding to spectrin-actin complexes on adducin was identified as the COOH-terminal tail of both the alpha- and beta-adducin subunits. The capacity of native adducin to recruit spectrin to actin filaments is similar to that of adducin tail domains. Thus, adducin tail domains alone are sufficient to interact with F-actin and a single spectrin and to recruit additional spectrin molecules to the ternary complex.

Note-taking skills of university students with and without learning disabilities

The notes of 30 university students with learning disabilities (LD) and 30 nondisabled university students were compared on the number of cued and noncued information units recorded and the number and type of abbreviations used. Results showed that the university students with LD performed significantly lower on all variables. Implications for practitioners are provided and future research discussed.

Protective immunity is induced by a Borrelia burgdorferi mutant that lacks OspA and OspB

A mutant of virulent Borrelia burgdorferi 297 was apparently selected for by long-term storage at 5 degrees C. This mutant was found to lack the plasmid which encodes outer surface protein A (OspA) and OspB. In addition to the loss of the OspA and OspB proteins, the mutant lacked two lipoproteins, of 20 and 7.5 kDa, that were observed in the wild type. Since the mutant was not recovered from the tissues or blood of hamsters injected with the mutant, the mutant was determined to be noninfectious. Hamsters vaccinated with noninfectious mutant 297 were protected completely from challenge with virulent wild-type 297 spirochetes. Prechallenge sera from hamsters vaccinated with mutant 297 lacked antibodies to OspA and OspB, while those from hamsters vaccinated with virulent wild-type 297 or avirulent 297 exhibited antibodies to these proteins. Hamsters vaccinated with virulent wild-type 297 or mutant 297 elicited antibodies to OspC and a 39-kDa protein (P39), whereas hamsters vaccinated with avirulent 297 lacked these antibodies. These results suggest that OspC and/or P39 are important for the development of a protective immune response. Study of this mutant may elucidate factors important to the development of a Lyme disease vaccine.

Isolation and characterization of Borrelia burgdorferi from blood of a bird captured in the Saint Croix River Valley

Field investigations were conducted to further evaluate the role of birds in the maintenance and dissemination of Borrelia burgdorferi. Blood specimens were taken from 39 passerine birds of 17 species captured during June 1991 at the Saint Croix National Riverway in Wisconsin, and one isolate, WI91-23, was cultured from an adult song sparrow (Melospiza melodia). This isolate was shown to be infectious for Peromyscus leucopus and Mesocricetus auratus (golden hamster). Isolate WI91-23 was confirmed as B. burgdorferi by immunofluorescence assay by using species-specific anti-OspA monoclonal antibodies H3TS and H5332 and anti-OspB antibody H5TS. Isolate WI91-23 was compared with Borrelia anserina Es, Borrelia hermsii MAN-1, and other B. burgdorferi strains (ATCC 53210, CT-1, and Catharus fuscescens [veery] liver 10293). Pulsed-field gel electrophoresis of in situ-lysed spirochetes revealed that the DNA plasmid profile of WI91-23 was most similar to those of plasmids from B. burgdorferi and most different from those of plasmids from B. anserina and B. hermsii. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that the protein profile of WI91-23 was like that of other B. burgdorferi strains studied, with dominant proteins corresponding to OspA and OspB, and that it differed from the protein profiles of B. anserina and B. hermsii. These findings indicate that passerine birds may serve as reservoirs for B. burgdorferi.

DNA analysis of Borrelia burgdorferi NCH-1, the first northcentral U.S. human Lyme disease isolate

The DNA of the first northcentral United States human Lyme disease isolate, Borrellia burgdorferi NCH-1, was characterized and compared with the DNAs of nine other B. burgdorferi isolates. Strain NCH-1 was isolated in August 1989 from a human skin biopsy specimen. DNA was analyzed by pulsed-field gel electrophoresis and restriction endonuclease analysis. Contour-clamped homogeneous electric field pulsed-field gel electrophoresis of in situ-lysed cells was performed to compare the plasmid profiles of the various isolates. The plasmid profile of isolate NCH-1, which included five plasmids of approximately 69, 42, 38, 32, and 23 kb, could be distinguished from those of the other isolates examined. The DNA profile of NCH-1 was most similar to those of strain 297 (human cerebrospinal fluid isolate, Connecticut) and strain PAL (human erythema migrans isolate, New York) and most dissimilar from those of strain P/Gau (human erythema migrans isolate, Germany) and strain IPF (Ixodes persulcatus tick isolate, Japan). These results indicate that genetic diversity exists among B. burgdorferi strains isolated from different geographical areas.

Electro-clinical correlations of positive and negative sharp waves on the temporal and central areas in premature infants

The goal of this study on 199 premature infants (24-41 weeks CA) was to investigate the electro-clinical correlations of positive and negative sharp waves, comparing those from the temporal and central areas. Positive discharges were seen more often less than 30 weeks CA and the negative type greater than 30 weeks. Patients without sharp waves rarely have seizures and those with paroxysms often do, dependent in part on the number of these discharges. When negative sharp waves are found on the frontal or occipital areas, where they uncommonly occur, the incidence of seizure almost doubles, compared to those on the central or temporal areas. Periventricular leukomalacia (PVL) was seen in less than one fourth of all patients, increasing to 32% with negative sharp waves, but nearly doubling the latter incidence with positive paroxysms, seen especially on the temporal, rather than central areas. Positive discharges were seen much more frequently with stage III-IV hemorrhage (Hg) than in stage I-II and these were mainly temporal, not central in location. Seizures and Hg were related only with grade III-IV, not with grade I-II Hg. Based on these data, positive sharp waves would predict in 69% of these infants the presence of at least one of the triad of seizures, intracerebral Hg or PVL, similar for the temporal and central locations. Follow-up studies showed that normal records at 30 weeks often changed to abnormal ones around 36 weeks. Finally, sensitivity data showed that for the positive sharp wave the highest values were for PVL, the lowest for seizures and midway for Hg, while the negative sharp waves show exactly the opposite, highest for seizures and lowest for PVL.

Methylated DNA in Borrelia species

The DNA of Borrelia species was examined for the presence of methylated GATC sequences. The relapsing-fever Borrelia sp., B. coriaceae, and only 3 of 22 strains of B. burgdorferi contained adenine methylation systems. B. anserina lacked an adenine methylation system. Fundamental differences in DNA methylation exist among members of the genus Borrelia.

The sharp theta rhythm on the occipital areas of prematures (STOP): a newly described waveform

This study on 500 prematures and neonates with conceptional ages (CA) of 23-49 wks describes the STOP pattern (sharp theta on the occipitals of prematures). STOP is similar to PT theta (premature temporal theta) in configuration, but is faster in frequency, lower in amplitude, more often unilateral, aside from the obvious difference in location. The incidence (%) was highest at the youngest age, decreasing to zero near term, and the amount (number of bursts) was greatest at 25 wks (CA). Three different parts appear in the incidence and amplitude curves, and these three parts may be related to changes in the laterality of the pattern. In the youngest age these rhythms are mainly bilateral, in the older neonates they are unilateral and are either for the ages between those extremes. STOP is seen more often in active sleep, but is reduced in incidence in patients with abnormal slow waves, ictal or immature patterns. Right-sided STOP was more frequently associated with abnormal EEGs, especially in males with right-sided sharp waves, often noted in the patients with seizures and intraventricular hemorrhages.

The relationship between EEG changes and cognitive functions in dementia: a study in a VA population

This study explores the relationship between the results of tests of dementia and the EEG findings in 94 demented patients of different etiologies. Abnormal EEGs were found in 83% of all patients, usually diffuse slow wave abnormalities, the degree of which correlated very well with the Modified Hachinski test. Only a weak relationship was found between the EEG and the Mini-Mental Status Examination, while the Mattis and its subtests correlated better. Focal EEG abnormalities on the temporal areas were the characteristic pattern in patients with alcoholic dementia. The test scores in the 17% with normal EEGs were consistent with the above findings, in that patients with normal tracings scored well on the Modified Hachinski and Mattis tests, but not on the Mini-Mental Status Exam.

Effect of fluoride on Treponema denticola

The effect of fluoride on the growth of Treponema denticola was studied. Fluoride, at a concentration of 20 micrograms/ml, was found to suppress the growth of all three strains tested. Growth was completely inhibited by 40 micrograms of fluoride per ml.

Duration of tonic immobility in chickens as a function of alpha-adrenergic receptor stimulation and blockade

Tonic immobility in chickens was influenced by a variety of drugs that act on the adrenergic neurochemical system of the body. Alpha 1 agonists such as methoxamine and phenylephrine produced decreases in the duration of immobility, although the former compound also caused a significant increase in the immobility response at high dosages. Alpha 2 agonists such as clonidine, naphazoline, and guanfacine enhanced the duration of immobility, but clonidine also produced an apparent reversal of this effect at high dosages. Subsequent experiments examined more fully the biphasic effects by methoxamine and clonidine on tonic immobility through interactions with alpha antagonists. Yohimbine, an alpha 2 blocker, attenuated the duration of immobility, either alone or in conjunction with various dosages of methoxamine. Prazosin, an alpha 1 blocker, had no direct effect on tonic immobility, but potentiated the duration of the response when given in conjunction with various dosages of methoxamine. When these antagonists were given in conjunction with clonidine, yohimbine reduced immobility durations, while prazosin had no apparent effect on this response. These results are discussed in terms of the relative contributions of the alpha 1 and alpha 2 adrenoceptors to the duration of the immobility response.

Disaccharidase activities in jejunal fluid

Jejunal fluid and mucosal tissue were obtained simultaneously from the same jejunal site in a group of 29 children by a modified biopsy procedure. Lactase, maltase, and sucrase activities were measured in both fluid and mucosal specimens using the same analytical method. The fluid enzyme activities showed highly significant positive correlations with the same enzyme activity in the relevant tissue samples. Relative concentrations of disaccharidase enzymes represented by sucrase: lactase activity ratios also showed a highly significant positive correlation between fluid and tissue. This close relation suggests that the mucosa is the sole or predominant source of disaccharidase activity in the intestinal fluid. The results of kinetic studies comparing tissue and fluid enzyme characteristics also indicate a mucosal origin for the fluid enzyme activities. We conclude that disaccharidase activities in jejunal fluid reflect closely local tissue values and that these measurements may be useful in assessing mucosal enzyme activity in infants in whom jejunal biopsy is not possible.

Total parenteral nutrition in infancy: effect on the liver and suggested pathogenesis

Biochemical, histological, and electron-microscopic investigation of seven preterm infants who became jaundiced after prolonged total parenteral nutrition showed conjugated hyperbilirubinaemia apparently due to cholestasis without significant primary liver cell injury. In the absence of evidence indicating a direct toxic effect on the liver of this form of nutrition the necropsy findings in one child and analogy with the effects of total parenteral nutrition in animals suggest that the cholestasis is the result of suppression of trophic and/or secretion-stimulating hormone(s) normally produced by the gut, due to absent enteral nutrition. Biochemical and electron-microscopic findings suggest that liver cell damage occurs after resumption of enteral nutrition.

The use of Doppler flow velocity measurement to assess the hemodynamic response to vasodilators in patients with heart failure

To determine if the hemodynamic response to vasodilator therapy can be assessed noninvasively by pulsed Doppler velocimetry, we compared the hemodynamic changes after treatment to changes in Doppler aortic blood flow measurements. The relationship between the absolute values and percent changes of invasively measured systemic vascular resistance (SVR) and stroke volume (SV) and Doppler-measured peak flow velocity (PFV), left ventricular ejection time (ET) and flow velocity integral (FVI) were evaluated. Measurements were made during 18 drug interventions in 13 patients treated with vasodilator agents for congestive heart failure (CHF). A poor correlation was found between the absolute values of either SVR or SV and the absolute values of each of the three Doppler aortic blood flow indexes studied. In contrast, a good correlation was found between percent changes in aortic PFV and in SVR (r = -0.89), and between percent changes in Doppler aortic FVI and in SV (r = 0.88). The correlation between percent changes in SVR and FVI revealed an r value of -0.65, while the correlation between percent changes in SVR and in ET showed an r value of -0.15. Percent changes in SV and either PFV or ET correlated with r values of 0.75 and 0.70, respectively. We conclude that Doppler aortic blood flow measurement can be used to assess quantitative changes in SVR and SV after vasodilator therapy. These findings suggest that it may be useful for evaluating vasodilator drug therapy in patients with CHF.

Differential effects of alpha-adrenergic antagonists on tonic immobility in domestic fowl

Groups of young chickens were injected with various dosages of several alpha-adrenergic antagonists and tested for the effects of these drugs on tonic immobility. Yohimbine, a very potent alpha2 antagonist, produced a significant decrease in the duration of tonic immobility at doses of 1 mg/kg, while prazosin, a potent alpha1 antagonist, had no apparent effect on immobility duration. Phentolamine, a on-specific alpha antagonist, produced a significant decrease in the duration of immobility at doses of 0.1 mg/kg, but had no effect at higher or lower doses. These results support the involvement of the alpha-adrenergic system with the duration of the tonic immobility reflex, but at the same time they also suggest that alpha2 receptors are more closely involved with the immobility response than alpha1 receptors. However, none of these drugs had any apparent effect on the initial susceptibility of subjects to the immobility reflex, as measured by the number of inductions required to produce tonic immobility.

Speed of change in pancreatic mass and in intestinal bacteriology of parenterally fed rats

1. Indices of pancreatic mass and bacterial counts for jejunal and ileal mucosa were studied in rats after 3, 6, 10 and 15 days of total parenteral nutrition and compared with the results from orally fed and sham intravenously fed control rats. 2. Pancreatic wet weight corrected for body weight decreased significantly by 31--42% after 3, 6, 10 and 15 days of total parenteral nutrition. The most striking decrease occurred within 3 days. Other indices of pancreatic mass (protein and DNA) showed a similar pattern suggesting pancreatic hypoplasia. There was more DNA per g of pancreas, indicating that unless there were changes in tissue water cellular hypotrophy must have accompanied the hypoplasia. 3. Pancreatic RNA also decreased significantly after 3--10 days of total parenteral nutrition, suggesting reduced protein synthesis. 4. Bacterial counts (log number) whether expressed as number/unit length of intestine or number/g wet weight of mucosa were decreased for anaerobic bacteria in the jejunum after 3--15 days of total parenteral nutrition. In the ileum both aerobic and anaerobic bacteria increased after 6 days of parenteral nutrition and then decreased significantly. 5. The changes in bacterial flora are unlikely to account for the adaptive hypoplasia seen in the intestine of intravenously fed rats.

Speed of onset of adaptive mucosal hypoplasia and hypofunction in the intestine of parenterally fed rats

1. To establish the speed on onset of jejunal and ileal mucosal hypoplasia and hypofunction in parenterally fed rats, we measured three indices of mucosal mass, three mucosal enzymes and quantitative histology after 3, 6, 10 and 15 days of total parenteral nutrition and compared the results with those in two orally fed control groups, one with and one without intravenous catheters and metabolic cage restraint. The kinetics of galactose absorption in vivo were also measured after 10 days of total parenteral nutrition and in both control groups. 2. The most striking decrease in both jejunal and ileal mucosal wet weight and protein and DNA content per 10 cm length of intestine, occurred after only 3 days of total parenteral nutrition; thereafter the mean values showed only a slight further decrease. 3. The results of the morphometric studies showed that the hypoplasia affected the villi slightly more than the crypts. Within 3 days of starting total parenteral nutrition, mean jejunal mucosal thickness decreased by 16% and after 15 days it had fallen by 28%. The ileum showed similar, although less marked, changes. In the jejunum (not the ileum) modest cellular hypotrophy accompanied the mucosal hypoplasia; there were more epithelial cells/unit length of mid-villus and there was more DNA per g of mucosa in the total parenteral nutrition group than in the control group of rats. 4. Jejunal galactose absorption from the 16, 32 and 64 mmol/l solutions was significantly less in the 10-day total parenteral nutrition rats than in the controls, the apparent Vmax. being five times greater in the orally fed animals. The apparent Michaelis constant (Km) was also significantly less than normal in the jejunum of the parenterally fed rats, suggesting increased affinity of the hypothetical carrier for galactose, perhaps as a result of functionally hypermature cells. 5. Mucosal alkaline phosphatase and catalase activities per unit length of intestine decreased and alpha-D-glucosidase activity increased in the jejunum and ileum of the total parenteral nutrition rats. 6. These results show that during total parenteral nutrition, the ileum and particularly the jejunum show marked reductions in mucosal mass and function after only 3 days of total parenteral nutrition and that there is a more gradual and progressive loss of mucosal mass thereafter up to 15 days.