Anti-nef antibodies and other predictors of disease progression in HIV-1 seropositive injecting drug users.

A cross-sectional and retrospective longitudinal study has been conducted in three Italian infectious disease centres to evaluate the role of anti-nef antibodies and other markers (HIV-1 p24 antigen, p24 Ag; Beta 2-microglobulin, B2-M; and number of CD4+ lymphocytes) as predictors of disease progression in HIV seropositive injecting drug users (IDUs). The selected patients were: 1) HIV-seropositive IDUs in different stages of HIV infection; 2) HIV-seropositive IDUs who had developed AIDS, from whom serial serum samples were available during the asymptomatic stage, and 3) HIV seropositive IDUs who remained asymptomatic through a follow-up period of the same duration as the patients who developed AIDS. Absence of anti-nef antibodies was associated with symptomatic HIV infection. A significant association between the absence of anti-nef antibodies, the presence of p24 Ag, high levels of B2-M, a number of CD4+ lymphocytes less than 500/ml at first visit and disease progression was found. Subjects who were persistently positive for antibody to nef were less likely to develop AIDS than those who were transiently or persistently negative. This difference was statistically significant (p = 0.03). The results of this study show that absence or disappearance of anti-nef antibodies may be used as predictor of disease evolution in HIV seropositive IDUs. This study also confirms the usefulness of other markers, such as p24 Ag, B2-M and number of CD4+ lymphocytes previously shown to be predictive of rapid disease progression for predicting the course of HIV seropositive IDUs.


Chronic intrajejunal TNBS application in TNBS-sensitized rats: a new model of chronic inflammatory bowel diseases.

An enteritis, based on a delayed-type hypersensitivity reaction, was induced in TNBS (2,4,4-trinitrobenzenesulfonic acid) sensitized rats by intrajejunal challenge with TNBS. This treatment induced a chronic inflammation of the distal small intestine, characterized by gross hyperaemia and oedema, as assessed by a macroscopic score. Histologically, the inflammatory response included cell infiltration by lymphocytes and histiocytes, a transmural granulomatous inflammation with multinucleated cells and activated mesenteric lymph nodes. Drug treatment with sulfasalazine or 5-aminosalicylic acid improved enteritis score. The applicability and relevance of this new model is discussed in relation to drug development and basic research of inflammatory bowel diseases.


Therapeutic interventions in gastrointestinal disease based on an understanding of inflammatory mediators.

Whatever initiates inflammation, the final message mediating cellular invasion is chemical. This consideration allows rational development of anti-inflammatory treatments. Two main classes of chemotactic mediator are recognised. Water-soluble peptides, e.g. cytokines derived from macrophages and other cells, play an important integrating part in the early recruitment of neutrophils and mononuclear cells, and in the amplification of immune responses. Lipid-soluble mediators, of which leukotriene B4 is the most highly chemotactic for neutrophils, are important in secondary amplification. In inflammatory bowel disease, we have shown evidence of increased synthesis of cytokines interleukin 1, 6 and 8. These are associated with activation of circulating monocytes in active Crohn's disease, of lamina propria macrophages in relapse of both ulcerative colitis and Crohn's disease, and development of adhesion molecules on vascular endothelium. Our studies show that interleukin 6 is selectively increased in Crohn's disease, whilst preliminary findings suggest that enhanced synthesis of interleukin 8 is particularly characteristic of ulcerative colitis. Patterns of cytokine synthesis may, therefore, be of diagnostic value. They also offer the potential for therapeutic strategies since cytokine antagonists are becoming available. We have also demonstrated increased synthesis of leukotrienes in active inflammatory bowel disease. Since leukotriene B4 is quantitatively the main chemotactic signal in the mucosa in inflammatory bowel disease during relapse, we investigated the therapeutic effect of suppressing leukotriene B4 synthesis by treating patients with fish oil (as Hi-EPA), giving 4.5 g daily of eicosapentaenoic acid. This competes for the 5-lipoxygenase enzymes, inhibiting leukotriene B4 and promoting synthesis of the less chemotactic product, LTB5.(ABSTRACT TRUNCATED AT 250 WORDS)


Cytokines and platelet-activating factor in human inflamed colonic mucosa.

Colonic biopsy specimens from patients with active ulcerative colitis and controls were incubated for four hours in the presence or absence of calcium ionophore or antihuman immunoglobulin E (IgE). Platelet-activating factor (PAF) was determined in the tissue by aggregation assay after extraction with 80% ethanol. PAF was not detected in normal mucosa, whereas A23187 and antihuman IgE stimulated its activity: mean +/- SE, 43.2 +/- 8.6 and 33.0 +/- 6.1 pg/10 mg wet weight, respectively. In active ulcerative colitis, A23187 and antihuman IgE induced significantly higher stimulation of PAF synthesis compared to their effects on normal mucosa. The enhanced stimulation of PAF induced by A23187 was dose-dependently inhibited by sulphasalazine, 5-aminosalicylic acid and prednisolone, but not by sulfapyridine. Colonic interleukin-1 content and release during 24 h of culture were significantly higher in patients with active ulcerative colitis and Crohn's disease compared to normal subjects. Prednisolone significantly and dose-dependently inhibited interleukin-1 release. These results suggest that colonic generation of PAF and interleukin-1 are elevated in patients with inflammatory bowel disease and, thus, may have a role in its pathogenesis. Pharmacological suppression of colonic PAF and interleukin-1 production may have beneficial therapeutic effects.


5-Lipoxygenase inhibitors for the treatment of inflammatory bowel disease.

The unique role of the enzyme 5-lipoxygenase (5-LO) in the production of leukotrienes (LTs) makes it a likely target for biochemical manipulation. The rationale for using 5-LO inhibitors for the treatment of inflammatory bowel disease (IBD) is based on the increased generation of LTs in the inflamed mucosa, LTB4 being the most potent chemotactic and chemokinetic metabolite of arachidonic acid. Furthermore, conventional drugs, such as corticosteroids, sulphasalazine, and 5-aminosalicylic acid, inhibit LT production and specific 5-LO inhibition accelerates healing in animal models of acute colitis. The compounds identified as 5-LO inhibitors can be divided into antioxidants, substrate-analogous, and a large miscellaneous group of inhibitors, where hydroxamic acids are potent and more selective inhibitors of 5-LO. The benzothiophene hydroxyurea, zileuton, is the first selective 5-LO inhibitor evaluated for the treatment of patients with IBD. An 800-mg oral dose of zileuton was shown to reduce LTB4, but not prostaglandin E2, concentrations by 75-85% in rectal dialysates from patients with active ulcerative colitis. The clinical efficacy of zileuton 800 mg b.i.d. has also been tested in a randomized, double-blind, placebo-controlled trial in similar patients. Zileuton significantly improved the symptom scores and the histology score, but not the sigmoidoscopy score, compared to pretreatment conditions and with response to placebo, the beneficial effects being most pronounced in patients not receiving concomitant sulphasalazine treatment. The mean inhibition of LTB4 in the target tissue of inflammation was 70%. The proof that any putative 5-LO inhibitor is blocking LT production is an important stage in assessing any such drug. The main disadvantage of existing new LT inhibitors relates to the high potency of LTs, and unless a higher level of inhibition can be achieved, endogenous LTs may still be present in sufficient amounts to produce their effects.


Schistosomiasis and the social patterning of infection.

Social, cultural, behavioural and economic factors interact with local environmental and ecological factors to produce extraordinary variation in the epidemiology of schistosomiasis, including with respect to prevalence and intensity of infection and the potential for control. This article reviews the literature on schistosomiasis infection, primarily derived from African studies, to identify its major social themes. Research has demonstrated a strong link between economic development strategies, where irrigation has been introduced to boost agricultural production, and the increased transmission of infection. Water-contact studies have provided the fullest and most detailed descriptions of social risk factors, and have isolated age, sex, religion and occupation as primary risk factors. However, fuller explorations of the social and cultural context of infection have yet to be undertaken. The social context of water-related behaviour and patterns of water use within communities and households, the intersection of social and economic activities, and the significance that people give to these activities, remains poorly explored, and although research papers concerned with community-based interventions refer to poor community understanding of the cause, prevention and treatment of the disease, this domain has also received little scholarly attention. Finally, economic studies have focused primarily on working capacity, and extrapolated these findings to generalize about the impact that this might have on productivity, but have yet to address either household or community costs of schistosomiasis infection.


Activity, mechanism of action and pharmacokinetics of 2-tert-butylbenzothiazole and CGP 6140 (amocarzine) antifilarial drugs.

A variety of recently developed drugs, designed to be used in antifilarial chemotherapy, contain a thiocarbonylamide group as a common structural element. One group of these compounds is based on a 2-tert-butylbenzothiazole ring in which the carbonylamide linkage is present as an isothiocyanate, dithiocarbamic acid ester or thiourea derivative. The single representative of another series is an N-methylpiperazine adduct of amoscanate (CGP 6140 or amocarzine). CGP 6140 is currently undergoing clinical trials in patients suffering from onchocercosis. All of the drugs with antifilarial activity affect the motility of filarial worms in vitro. The primary site of action of most of these compounds is the mitochondrion. The drugs result in the swelling of this organelle and also the inhibition of respiration and other associated metabolic functions. The dithiocarbamic acid esters (e.g., CGP 20376) are devoid of intrinsic antifilarial activity. Activity of these compounds requires conversion to the corresponding isothiocyanates. This occurs spontaneously in aqueous solution at physiological pH. The thiourea compounds were found to inhibit acetylcholinesterase activity by competing with its substrate. There is also evidence that the latter drugs are metabolized by a host-derived enzyme to their isothiocyanate analogs. CGP 6140 affects both mitochondrial function and acetylcholinesterase activity. The biochemical effects of the antifilarial compounds were not found to be significantly different between mammalian and parasite test systems. Biochemical and pharmacokinetic studies suggest that the selective toxicity of the new series of drugs towards filarial parasites is most likely preferential drug uptake by the pathogen. The lack of a unique target for these compounds in the parasite may explain the side-effects seen upon their administration to humans.


The influence of the size of the initial inoculum on the efficacy of isometamidium (samorin) on a stock of Trypanosoma congolense.

The effect of the number of trypanosomes in the initial inoculum on the minimum curative dose, was determined for an experimental infection of Trypanosoma congolense in mice treated with isometamidium. Mice were infected by the intravenous route and were then treated three hours later by intraperitoneal injection. The minimum curative dose was shown to be dependent on the size of the initial inoculum, with a difference of a factor of 7.5 as the initial inoculum was increased from 10(3) to 10(6) trypanosomes per mouse. It is concluded that this may be a significant variable for in vivo drug sensitivity test, and may also have implications for treatment of infections in the field.


Influence of D(+)-glucosamine on infection rates and parasite loads in tsetse flies (Glossina spp.) infected with Trypanosoma brucei.

Teneral Glossina morsitans centralis, G. m. morsitans and G. pallidipes were infected with three different clones of Trypanosoma brucei in blood containing D(+)-glucosamine, an inhibitor of tsetse midgut lectin. On average, 5 days of D(+)-glucosamine treatment tripled infection rates, without affecting the proportion of infections that matured. Total infection rates were equal in males and females, but twice as many infections matured in males. Counts of parasites in the guts and salivary glands of 277 flies revealed order of magnitude differences among flies, with females consistently having 2-3-times as many parasites as males. Parasite numbers varied in a sex-specific manner among tsetse-clone combinations, but these differences were not correlated with similar large differences in infection rates. D(+)-glucosamine treatment had no significant effect on parasite loads.


Development of multiple drug resistance of Trypanosoma congolense in Zebu cattle under high natural tsetse fly challenge in the pastoral zone of Samorogouan, Burkina Faso.

Preliminary data from an ongoing epidemiological survey in the pastoral zone of Samorogouan (Kénédougou) indicate the occurrence of multiple-drug-resistant Trypanosoma congolense. Despite frequent trypanocidal drug treatments with diminazene aceturate (Berenil, Hoechst) at 7 mg/kg body weight (bw) at intervals of 2 to 4 weeks, no significant drop in the prevalence of African animal trypanosomosis (AAT) was observed. To examine a suspected drug resistance, 20 Zebu cattle, naturally infected with T. congolense and/or T. vivax, were transferred in December 1989 from Samorogouan into a fly-proof stable. Diminazene aceturate at 7 mg/kg bw cured infections of T. vivax, but was ineffective against T. congolense. Likewise, treatments with homidium bromide (Ethidium, FBC) at 1 mg/kg bw and isometamidium chloride (Trypamidium, Rhône Mérieux) at 1 mg/kg bw, respectively, proved to be ineffective. Corresponding chemotherapeutic trials in previously unexposed Zebu bulls and Sahelian goats infected with one primary T. congolense isolate from Samorogouan demonstrated a high level of resistance to diminazene aceturate (7 mg/kg bw in cattle and 17.5 mg/kg bw in goats), isometamidium chloride (1 and 2 mg/kg bw i.v. in goats) and quinapyramine sulphate (Trypacide'S', Rhône Mérieux) at 5 mg/kg bw in goats. The appearance of a multiple-drug-resistant strain of T. congolense emphasizes the urgent need for new chemical substances as trypanocidal drugs and the increasing importance of efficient vector control.


An in vitro model for screening antileishmanial drugs: the human leukaemia monocyte cell line, THP-1.

Standard anti-leishmanial drugs were tested for their ability to inhibit the growth of intracellular amastigotes of Leishmania aethiopica, L. donovani and L. infantum in the human leukemia monocyte THP-1 cell line. Sodium stibogluconate and meglumine antimoniate were active against L. donovani with ED50 values of 8.9 micrograms SbV/ml and 2.9 micrograms SbV/ml, respectively. L. aethiopica was less sensitive to sodium stibogluconate with an ED50 value of 25.3 micrograms SbV/ml while pentamidine had an ED50 value of 0.6 microM. Both L. donovani (ED50, 9.3 microM), and L. aethiopica (ED50, 6.4 microM), were sensitive to aminosidine sulphate. An L. infantum isolate, clinically resistant to meglumine antimoniate treatment, had an ED50 of 22.2 micrograms SbV/ml. The toxic level of drugs on host cells was determined by colorimetric Methyl Tetrazolium (MTT) assay prior to activity tests. The results obtained with the THP-1 in vitro drug screening model were similar to those obtained in the mouse peritoneal macrophage model.


Comparative evaluation of the colony-stimulating factors induction potential of Plasmodium cynomolgi-infected monkey erythrocytes and soluble antigens.

Plasmodium cynomolgi total antigens soluble in culture medium (P.c.SA), and noninfective P. cynomolgi-infected monkey erythrocytes (P.c.IE) were compared for their potential to induce colony-stimulating factors (CSFs). When injected intravenously in monkeys, both preparations induced an increase in the serum CSFs levels; P.c.IE appeared to be 1.6-fold more potent than the P.c.SA. In vitro P.c.IE induced 1.8-fold more CSF by monkey blood monocyte-derived macrophages than P.c. However, both in vivo and in vitro, the peak CSFs levels induced by P.c.SA were attained apparently 8 h earlier. CSF generated by P.c.SA and P.c.IE induced the formation of macrophage, granulocyte and granulocyte-macrophage colonies, in vitro; P.c.IE-generated CSF induced the formation of significantly (P < 0.01) higher numbers of granulocyte-macrophage colonies, indicating that the CSF induced by them stimulated different biological responses. The CSF induction appeared to be LPS-independent.


Vector competence of Glossina pallidipes and G. morsitans centralis for Trypanosoma vivax, T. congolense and T. b. brucei.

Vector competence of Glossina pallidipes for pathogenic Trypanosoma species was compared to that of G. morsitans centralis. Cattle or goats were the hosts used to infect teneral tsetse, rabbits were used to maintain tsetse which were dissected on day 30. Mean infection rates of G. pallidipes and G. m. centralis by T. vivax isolated from a cow in Kenya were respectively 39.5 +/- 8.9% and 32.1 +/- 10.3% whilst for T. vivax isolated from a cow in Nigeria, they were 30.0 +/- 7.5% and 19.8 +/- 4.3%. Differences were not significant. Differences in infection rates between the sexes of flies were also not significant. Transmission capability to goats by either tsetse species was good for the two T. vivax isolates. Mean infection rates by T. congolense isolated from a lion in Tanzania were significantly lower in G. pallidipes (8.5 +/- 1.8%) than in G. m. centralis (22.5 +/- 2.0%). Males of either tsetse were more susceptible than females. Transmission rates to goats and mice by both tsetse species was 100%. G. pallidipes (3.5%) was less susceptible than G. m. centralis (25.1%) to T. congolense isolated from a cow in Nigeria, but transmission rates to goats and mice by either tsetse was 100%. Also, G. pallidipes (2.7 +/- 0.4%) was significantly less susceptible than G. m. centralis (18.4 +/- 1.1%) to T. b. brucei isolated from a hartebeest in Tanzania. Males of either tsetse species were more susceptible than females. Transmission rates to goats and mice by either tsetse was 100%. G. pallidipes (0%) was not susceptible to T. b. brucei isolated from a pig in Nigeria whilst G. m. centralis showed infection rate of 9.3%. When male G. pallidipes and G. m. centralis were fed every day for 27 days on a goat infected with this T. b. brucei from Nigeria, the infection rates were 8.7% and 20.2%, respectively. Transmission rates to mice by either tsetse species was 100%. In conclusion, G. pallidipes has a vector competence equal to that of G. m. centralis for T. vivax, whilst G. pallidipes has lower vector competence than G. m. centralis for T. congolense and T. b. brucei.


Sonographic organometry in Brazilian and Sudanese patients with hepatosplenic schistosomiasis mansoni and its relation to the risk of bleeding from oesophageal varices.

Fifty-nine patients with hepatosplenic schistosomiasis mansoni were investigated by sonography in Northeast Brazil and Central Sudan. The sizes of the organs usually involved in this disease were quantitatively assessed according to a standardized protocol, and measurements were adjusted to the body height of the individual. The results were compared with those of healthy controls matched by sex, age, geographical origin and socio-economic status. Considerable differences were found between patients and controls as well as between residents from the two areas. The liver of both patients and controls from the Sudan was significantly smaller than that of patients and controls from Brazil. Only in Brazil, but not in the Sudan, was the left liver lobe larger in patients than in the controls. The diameter of the portal and the splenic vein, the spleen size and the thickness of the gallbladder wall were significantly increased in patients from both areas. The increase of the portal and splenic vein diameter was significantly correlated with the degree of hepatic periportal fibrosis and the frequency of bleeding from endoscopically proven oesophageal varices in the patients, irrespective of their geographic origin. In contrast, such correlations were not found for the degree of splenomegaly nor for the degree of gallbladder-wall thickening. It is concluded that standardized sonographic organometry permits the assessment of morbidity in hepatosplenic schistosomiasis mansoni under different endemic conditions. Especially the measurement of the portal vein diameter may allow estimation of the risk of gastrointestinal haemorrhage in these patients.


Recombinant kinetoplast DNA (kDNA) probe for identifying Leishmania tropica.

The paper reports on the construction of a kDNA library with DNA isolated from the WHO reference strain of Leishmania tropica IC-305 and subsequent identification and propagation of recombinant plasmids containing L. tropica kDNA sequences. It also shows that the cloned kDNA sequences can be used as genetic markers in restriction endonuclease, Southern blot transfer, and dot blot hybridisation analysis, to identify L. tropica parasites. When the pL 305-I kDNA probe was used in hybridisation experiments with DNAs from various Leishmania reference strains, species and isolates from different host species and from different geographical locations, hybridisation was detected only with L. tropica, thereby suggesting that the insert in recombinant plasmid 305-I was species-specific. The probe is sensitive to the level of 10(3) parasites in dot blot hybridisation. Additionally, orthogonal field alternation gel electrophoresis (OFAGE) and transverse alternating field electrophoresis (TAFE) were used to characterise Leishmania reference strains and Leishmania species. The molecular karyotypes resolved by these techniques showed significant differences in the profiles of chromosomal sized-DNA molecules among species of Leishmania. The DNA karyotypes of the two reference strains of L. tropica (IC-305 and NLB-067), while similar, were nevertheless distinct.


Glycolipid and protein profiles of normal and Trypanosoma cruzi infected heart muscle cells.

Using Triton X-114, glycolipids and proteins were extracted from heart muscle cells (HMC) infected with Trypanosoma cruzi clone Dm28c and from uninfected HMC, and analysed by SDS-PAGE and high-performance thin-layer chromatography (HPTLC). Two major differences were observed: (a) two proteins with a molecular mass of 92 kDa and 69 kDa were present in the uninfected cells but absent from the infected cells and (b) a 70-90 kDa protein band was detected only in parasitized cells. These differences would seem to constitute alterations taking place during the process of cell recognition and/or parasite interiorization. No differences were observed in the respective glycolipid compositions, of control and infected cells analysed by HPTLC. A glycolipid with the same mobility as the neutral glycolipid isolated from epimastigotes of T. cruzi was detected in the uninfected cells. This finding may lend support to the previously described hypothesis that molecular mimicry is implicated in the cardioneuropathology of Chagas' disease.


The role of temperature and nutritional status in flight initiation by Triatoma infestans.

Flight initiation in Triatoma infestans is associated with low nutritional status and increases with rising temperature; it appears to be largely independent of bug age and sex. A predictive model for the probability of flight initiation was constructed based on weight:length ratios of the bugs and maximum ambient temperature, both of which can be ascertained in the field. The model accurately predicted the proportion of bugs initiating flight in > 85% of the groups used in our study. The predictive equation was found to give significant fits with two independent data sets. From our results it might be expected that flight would be rare during colder (< 20 degrees C) months but that 5-10% of the normal population of an infested house would fly on any given night during the hotter months when temperatures approach 30 degrees C. If bug nutritional status falls significantly, this proportion could be expected to rise to 30%.


Epidemiology of bovine brucellosis in the coastal savanna zone of Ghana.

323 sera from cattle raised in four locations in a coastal savanna area of Ghana were screened for brucellosis using the Rose Bengal plate test. The overall prevalence rate was 9.3%. No significant difference was seen between the infection rates in females (11.3%) and in males (4.3%). Generally, regardless of the sex of the animal, older animals (> or = 2 years) had significantly higher infection rates (11.6%) than younger animals (3.5%). In the females, the older animals had a relatively higher infection rate (13.5%) compared to nil (0) for the younger ones. However, in the males the converse was true, with younger animals having a relatively higher infection rate (6%) compared to the matured males (2.4%). 31% of the 42 herds examined tested positive for brucella antibodies in the Rose Bengal plate test. The need to monitor bovine brucellosis and educate the population at risk on dangers of infection is emphasised.


Diagnosis of New World leishmaniasis: specific detection of species of the Leishmania braziliensis complex by amplification of kinetoplast DNA.

We have sequenced single kinetoplast DNA minicircles from three species and part of a minicircle from the fourth major species within the Leishmania braziliensis complex. Alignment of these sequences with each other and with those of other kinetoplastids allowed the selection of a pair of oligonucleotides suitable as primers in a polymerase chain reaction which is highly specific for the Leishmania braziliensis complex. The reaction is capable of detecting less than one femtogramme of kinetoplast DNA. It has been tested with crude specimens from South American leishmaniasis patients, potential wild animal reservoirs and sandfly vectors. The tests indicate that these primers are suitable for diagnosis of leishmaniasis and potentially useful in epidemiological surveys.


Plasmodicidal effect of desferrioxamine B in human vivax or falciparum malaria from Thailand.

Desferrioxamine B (DFO, Desferal), an iron chelator, was earlier shown to be active against Plasmodium falciparum in vitro and in vivo. The present open pilot study served to assess its clinical tolerability and efficacy in human malaria under hospital conditions. Continuous intravenous DFO was administered to 28 Thai males at a dose of 100 mg/kg over 24 h for 3 consecutive days. No other antimalarial therapy was administered unless recrudescence had occurred. The first 14 patients had symptomatic Plasmodium vivax (P.v.) malaria, while the other 14 patients were suffering from uncomplicated Plasmodium falciparum malaria (P.f.). Both groups were treated in Bangkok, where malaria transmission does not take place, and followed up, on the ward, for 3 weeks (P.v. group) or 4 weeks (P.f. group) after the start of therapy. In both groups DFO reduced the parasitaemia to zero within 106 and 57 h respectively. The fever clearance time was 55 and 60 h, respectively. The overall tolerability of DFO was good but 4 P.v. and 5 P.f. patients had transient visual blurring. Recrudescences were observed on average 15, respectively 10 days after the start of therapy. Only 2 P.v. patients and none of the P.f. patients remained free of recrudescences during the observation period. There was no apparent gametocytocidal effect of DFO on P.f.


Structural differences between the chromatin of procyclic Trypanosoma brucei brucei and of higher eukaryotes as probed by immobilized trypsin.

Soluble chromatin of Trypanosoma brucei brucei procyclic culture forms was submitted to digestion with free or immobilized trypsin. Digestion with trypsin in salt solutions of low and high ionic strengths generated characteristic sets of limit histone peptides. After incubation of chromatin with immobilized trypsin in a solution of low ionic strength, histones were not degraded, whereas a selective proteolysis occurred at 50 mM NaCl. Histones a and d, which correspond to H3 and H4 of higher eukaryotes, were rapidly attacked. Histones b and c, the counterparts of H2A and H2B, were more resistant. The results indicated that probably the basic N-terminal tails of the proteins a and d are located on the surface of the core particle. The location of d on the surface differs from the internal one proposed for histone H4. The salt-induced increase of susceptibility of histones to proteolysis reflects structural changes of T.b. brucei chromatin, which may result in partial chromatin compaction.


Quantitative reconstitution of isolated influenza haemagglutinin into liposomes by the detergent method and the immunogenicity of haemagglutinin liposomes.

The reconstitution of influenza virus haemagglutinin into liposomes from lipid/protein/detergent mixtures by detergent removal provides vesicles that are similar in structure to viral particles. The dissociation properties of haemagglutinin aggregates and the molar ratio of lipid to protein in the starting mixture are the key factors for the individual and total yield of protein incorporation into liposomes. Structural properties of the detergent used as well as special reconstitution conditions are of minor importance for the formation of haemagglutinin liposomes. As determined by radial immunodiffusion-, haemolysis- and fusion experiments, specific properties of haemagglutinin were maintained to a large extent on liposomal incorporation, but its immunogenicity is increased, if the antigen is incorporated into the lipid bilayer of liposomes.


Antigenic and molecular analysis of influenza A(H3N2) virus strains isolated in 1985 in open and closed communities of northern Germany.

Antigenic and molecular analyses of influenza A(H3N2) virus strains isolated in 1985 during outbreaks in open and closed communities of North Germany were carried out. The data obtained have shown that 11 strains isolated in a closed orphanage were antigenically similar to each other. The electrophoretic mobilities of either HA, NP, M1 and NS1 polypeptides or of double stranded RNA segments were indistinguishable. Analysis of viruses isolated at the same time from open communities has revealed that they contained at least three groups of strains differing in homology of 3-5 RNA segments. These data support the idea that an outbreak of influenza in a community is caused by single virus strain, from which their slightly different variants of the virus arise during circulation among sensitive persons.


Virus-specific immune response in the lungs of mice infected with influenza virus.

The time course of primary humoral immune response in NFS/N mice infected with the adapted influenza virus A/Aichi 2/68(H3N2) was followed by determination of the different class immunoglobulins in lungs, lung washings, and in blood serum. The quantity of antibody-producing cells (APC) was estimated by local haemolysis in gel. The presence of antibodies in serum and lavage fluid was tested by the methods of radial haemolysis and radial immunodiffusion. It was shown that the local immune response had developed earlier than systemic antibodies occurred in the serum.


Virus neutralizing antibodies at different stages of the HIV disease: increased levels after azidothymidine treatment.

Specific HIV-1 neutralizing activity was measured in single serum samples obtained from 52 individuals suffering from different stage of HIV disease, as well as in serum samples collected during a four years follow up of other 13 HIV-1 seropositive persons, from whose seven developed AIDS. Three of these persons were treated with azidothymidine. In the former group of single serum specimens, the specific neutralizing antibody positivity rate was 81 per cent in symptomless persons, 92 per cent in patients with ARC and 43 per cent in patients with AIDS. From 13 HIV-1 infected individuals, prospectively investigated from 1986 to 1990, six remained asymptomatic and no significant fluctuation of specific virus neutralizing antibody levels was noted. During this time period, remaining seven patients developed AIDS. In the sera of AIDS patients, specific neutralizing activity was either not detected or its titres were rather low before the appearance of clinical disease. Three AIDS patients were administered azidothymidine. Specific neutralizing antibody titres increased significantly one month after the beginning of azidothymidine administration and persisted at relatively high levels over several months of follow up.


On the antiviral activity of diffusomycin (oxazolomycin).

The effect of the beta-lactone antibiotic diffusomycin (oxazolomycin) was investigated against vaccinia (Lister), herpes simplex type 1 (Kupka), influenza A (WSN; H1N1), and Coxsackie A9 viruses. Diffusomycin reduced significantly the plaque formation of enveloped DNA and RNA viruses by more than 90% in the range of the maximally tolerated dose. As could be shown with vaccinia virus, the antiviral action was not caused by virucidal effect on virions or by interaction with virus adsorption and penetration. In one-step growth cycle assays diffusomycin prevented the replication of herpes simplex type 1, vaccinia and influenza A viruses in a dose-dependent manner. The replication of influenza A viruses was blocked immediately after addition of the compound during zero to six hr p.i. Partial reversibility of the antiviral action was established by washing off the antibiotic from chicken embryo cells (CEC) infected with influenza A virus. Finally, replication of Coxsackie A9 virus was not inhibited by diffusomycin. Electron-optical studies revealed a reduced synthesis of HSV-1 nucleocapsids in dependence on the concentration of the compound.


Molecular characterization of cloned variants of Coxiella burnetii isolated in China.

To study the molecular properties of Coxiella burnetii phase variants we cloned the phase variants of C. burnetii Qiyi (CBQY) strain by the red plaque technique. Three cloned strains, CBQYIC3 (phase I), CBQYIIC7 (phase II) and CBQYIIC5 (semirough-phase) were analysed by SDS-PAGE, immunoblot assay, plasmid isolation and agarose gel electrophoresis of DNA restriction fragments. The results suggest that the unique phase-dependent substance is a lipopolysaccharide and that most protein components of phase I and phase II cells are shared. No significant differences of DNA restriction fragments were found between clonal isolates of phase I and phase II C. burnetii CBQY strains. A plasmid of approximately 56 Kb was isolated from both phase I and phase II variants indicating that phase variation probably could not be attributed to its presence or absence.


Analysis of the coat proteins of the ordinary and Andean strains of potato virus S and antigenic comparisons of carlaviruses.

The coat proteins of both ordinary (PVSO) and Andean (PVSA) strains were shown to be similar in molecular weights, peptide maps, amino acid analysis and reaction to a range of carlavirus antiseras.


Characterization, purification and serology of the Czechoslovak isolate of radish mosaic virus.

The radish mosaic virus 1 (RMV 1) isolate was characterized according to the reaction of differential test plants and then purified by the chloroform-butanol method. UV-analysis of sucrose density gradients at 254 nm revealed three components. The values of A260/280 ratio were 1.42 for the top, 1.49 for the middle and 1.67 for the bottom component, respectively. Electron microscopy of the purified virus revealed isometric particles about 30 nm in diameter. Two antisera were prepared with the titre 1:1024 and 1:2048, respectively. The RMV 1 antigen formed a distinct precipitation line with the antiserum against the California neo-type strain of RMV.


Some physicochemical properties of murine herpes virus.

The effect of incubation temperature variation and various pH values on the stability of murine herpesvirus isolate-76 (MHV-76) was investigated. The virus survival in rabbit embryo fibroblasts cells (REF) has been determined. At room temperature (23 degrees C) 50% of the virus became inactivated during 12 days and at 37 degrees C its half life was 9 days. MHV-76 was completely inactivated at 50 degrees C in 1 hr or at 41 degrees C in 7 hrs. MHV-76 retains its maximal infectivity at the pH range between 6-9 regardless of the duration of treatment. The pH range 3, 4, 5 and 10, 11, 12 caused either complete or more or less expressed inactivation of the virus. A complete inactivation MHV-76 was also achieved after treatment with ethyl ether, chloroform and 2M urea.


Skin virulence of attenuated pseudorabies virus (PRV) strains.

After intradermal inoculation of the attenuated pseudorabies virus (PRV) strains, Bartha, MK35 (gI+) and MK35-T-2 (gI-) to rabbits, they caused local inflammatory nodules with oedema reddiness and necrosis. The specifity of these reactions was confirmed by their inhibition with anti-PRV serum. The minimal dose that caused visible skin reaction was about 10(2) TCID50/ml for Bartha and MK35-T-2 (gI-) strains and over 10(4) TCID50/ml for the MK35 (gI+) strain. It is assumed that the established residual skin virulence can serve as an additional distinction marker for attenuated PRV strains.


DNA regions and genes determining the virulence of herpes simplex virus.

The outcome of virus-host interaction after peripheral inoculation of herpes simplex virus (HSV) depends on virus replication at the portal of entry, the ability of the virus to invade nerve endings and capillary endothelium cells and, the rate of virus replication in neurons and nonneural cells of the nervous system. Functions involved are the activity of viral thymidine kinase, DNA polymerase, immediate early transactivator proteins, the transcription initiation protein, the envelope protein(s) governing virus penetration, syncytium formation and natural killing of infected cells as well as some other regulatory DNA sequences.


T-cell receptor gene polymorphisms in familial cardiomyopathy: correlation with anti-beta-receptor autoantibodies.

Cardiac autoantibodies have been detected in a significant proportion of patients with dilated cardiomyopathy, but their relation to the pathogenesis of the disease remains unknown. This issue was examined in 41 members of an Ohio family with a heritable disorder of the cardiac conduction system and the myocardium. In 41.5% of all members studied, serum anti-beta-receptor antibodies were identified by a combination of techniques: ligand binding inhibition assay, enzyme-linked immunoassay of a beta 1-receptor peptide, and adenylate cyclase inhibition. The prevalence of autoantibodies was significantly higher (p < 0.01) in the affected (64.7%) than in the unaffected (25.0%) members. A 10.0 kb restriction fragment length polymorphism of the C beta region of the T-cell receptor gene was also overrepresented in affected males (60% versus 30% unaffected males, p < 0.01). In males, the presence of anti-beta-receptor antibodies was linked to the 10.0 kb C beta polymorphism. In affected males, a BlgII C alpha 2.14 kb polymorphism was also more frequent (62% versus 32% in unaffected, p < 0.01) and was linked to the presence of anti-beta-receptor antibodies. The distribution of haplotypes defined by V beta 8, C alpha, and C beta probes was significantly different between affected and unaffected (p < 0.04) and between antibody-positive and antibody-negative individuals. Since the major function of the T-cell receptor is the recognition of processed autoantigens, these results provide additional support for the role of autoimmunity in dilated cardiomyopathy.


Instantaneous cardiac death in the posthospital period after acute myocardial infarction.

Sudden arrhythmic cardiac death is a major unresolved health problem, yet there is no agreement on the chronologic definition of sudden death. This retrospective study investigates the frequency distribution of the chronology of the terminal cardiac event in a large postinfarction population and identifies factors associated with instantaneous (< 1 minute) cardiac death. This study involved 229 patients enrolled in the Multicenter Diltiazem Post-infarction Trial who died during 2-year follow-up and had quantitative information on the chronology of the terminal event. Thirty-two percent of the cardiac deaths occurred instantaneously. Patients who died instantaneously were more likely (p < 0.05) to be men, to have a baseline ejection fraction < 0.40, and to have frequent (> or = 10/hour) and repetitive (> or = 3 in a row) ventricular ectopic complexes (VECs) on an ambulatory electrocardiogram than those who did not die instantaneously. Patients who died instantaneously received more digitalis and class IA antiarrhythmic agents and less beta blockers in the week before death than those dying noninstantaneously. Logistic regression analysis identified 3 independent factors that differentiated instantaneous from noninstantaneous death (relative risk; 95% confidence interval): frequent VECs (2.15; 1.11 to 4.17); digitalis (2.57; 1.31 to 5.06); and no beta blocker medication (2.90; 1.09 to 7.75). Instantaneous death (within 1 minute) was responsible for almost one third of the cardiac deaths that occurred in this postinfarction population. Frequent VECs, digitalis, and absence of beta-blocker therapy distinguished patients who died instantaneously from those who died noninstantaneously.


Pulmonary infiltrates and skin pigmentation associated with sulfasalazine.

A patient with ulcerative colitis developed skin pigmentation and diffuse pulmonary shadowing without respiratory symptomatology, while taking sulfasalazine. The clinical picture and radiological abnormalities disappeared spontaneously on discontinuation of the drug. Histopathological studies from specimens taken by transbronchial biopsy showed bronchiolitis obliterans with fibrosing alveolitis. Sulfasalazine-induced lung disorder is an extremely rare entity which must be considered in all ulcerative colitis patients while on sulfasalazine therapy, despite the absence of pulmonary symptomatology.


Salmeterol xinafoate: a review of its pharmacological properties and therapeutic potential in reversible obstructive airways disease.

Salmeterol xinafoate, like salbutamol (albuterol), is a saligenin derivative, and a selective beta 2-adrenoceptor agonist. It produces bronchodilation for at least 12 hours following inhalation of a single 50 micrograms dose. Salmeterol is intended for regular twice-daily treatment of reversible airways obstruction and not for immediate symptomatic relief, and when used in this manner. 50 micrograms twice daily is more effective than salbutamol 200 micrograms or terbutaline 500 micrograms administered 4 times daily, or individually titrated oral doses of theophylline in improving objective and subjective criteria of efficacy in patients with mild to moderate asthma. Salmeterol 100 micrograms inhaled twice daily may provide better control than the lower dose in patients with severe asthma. The long duration of effect of salmeterol makes it particularly suitable for treating patients with nocturnal asthma in whom it improves sleep quality. The place of salmeterol, like that of other beta 2-adrenoceptor agonists used regularly in the treatment of asthma, is being debated. Patients in need of regular beta 2-agonist therapy should also be regarded as candidates for inhaled corticosteroids to counteract underlying inflammation. Thus, salmeterol may be particularly useful in patients requiring regular treatment with beta 2-agonists for nocturnal asthma and results of trials in progress involving large numbers of patients are awaited with interest.


Familial IgA nephropathy: a study of HLA class II allogenotypes in a Chinese kindred.

We have studied the restriction fragment length polymorphism (RFLP) of the major histocompatibility complex (MHC) class II DQ, DR pattern of a Chinese family with IgA nephropathy (IgAN). The three affected and one apparently unaffected sibling shared the same DR and DQ pattern. The subjects were homozygous for DRw12, DQw7, DQ alpha 1b. The DQw7 allele was further confirmed by polymerase chain reaction (PCR) and allele-specific oligonucleotide (ASO) probing. This study confirms that IgAN can run in a family and is consistent with the possible immunopathogenetic effects of MHC class II antigens on IgAN.


Renal artery stenosis modifies glomerular injury in antineutrophil cytoplasmic antibody-associated disease.

A 68-year-old man presented with renal failure, heart failure, gastrointestinal bleeding, and a pulmonary infiltrate. Serologic evaluation revealed a perinuclear antineutrophil cytoplasmic antibody (ANCA) at a titer of 1:1280, which on immunoblot and enzyme immunoassay showed antimyeloperoxidase specificity. Autopsy showed microscopic polyarteritis based on the presence of necrotizing alveolitis and crescentic glomerulonephritis. The extent and activity of the glomerular disease was modified by a right renal artery stenosis (RAS). Twenty percent of glomeruli on the right and 82% glomeruli on the left contained crescentic lesions. Furthermore, predominantly active lesions were associated with renal artery stenosis, while the contralateral kidney contained mostly organized crescents. This observation suggests that hemodynamic factors or its sequelae can influence the onset and severity of ANCA-associated disease.


The many faces of scleroderma.

This review integrates the clinical aspects of systemic sclerosis (SSc; scleroderma) and scleroderma-like conditions with new knowledge of the control of blood vessel tone and the role of anoxia in the activation of connective tissues leading to fibrosis. Serologic tests, high resolution computed tomographic scanning, bronchoalveolar lavage, and physiologic assessment of pulmonary gas diffusion are compared as diagnostic tools and as means of quantitating internal organ involvement. Treatment of Raynaud's disease and phenomenon, management of scleroderma renal crisis, and new means for improving gastrointestinal function with octreotide, the somatostatin analogue, also are discussed. The relationship between idiopathic forms of SSc and eosinophilic fasciitis/eosinophilia-myalgia syndrome caused by L-tryptophan ingestion and the scleroderma-like disease associated with silicone breast implants also is discussed.


Elevated sulfatide excretion in heterozygotes of metachromatic leukodystrophy: dependence on reduction of arylsulfatase A activity.

Sulfatide excretion in urine and arylsulfatase A (ASA) activity in leukocytes were determined in 10 homozygotes of metachromatic leukodystrophy (MLD), 7 obligate and 5 facultative MLD heterozygotes, 6 low ASA subjects (not related to MLD homozygotes), and in 9 controls. As compared to controls (sulfatides: 0-2 nmol/mg lipid; ASA: 101-287 nmol p-nitrocatechol/mg protein/hr), MLD homozygotes displayed highly increased sulfatide excretions (27-280 nmol) and low residual ASA activities (0-13 nmol). Of 12 MLD heterozygotes (ASA: 18-87 nmol) 10 showed increased sulfatides (3-24 nmol). All heterozygotes with ASA activity < 60 nmol (n = 8) had elevated sulfatide excretions (4-24 nmol). Thus, reduction of ASA activity below 40% of the mean value of controls seems to be the critical threshold for elevated sulfatide excretion in MLD heterozygotes. The low ASA subjects (ASA in the heterozygote range) excreted sulfatides in the control range, even those with ASA activities < 60 nmoles (n = 3; including a definite homozygote for ASA-pseudodeficiency; ASA:25 nmol). Statistical evaluation of sulfatide excretion and ASA activity in all subjects (n = 37) revealed a significant inverse relation (Spearman rank correlation; R = 0.8278, P < 0.001). The finding of elevated sulfatide excretion in certain MLD heterozygotes might point to increase of sulfatides also in the nervous system.


Survival and disease progression in human immunodeficiency virus-infected women after an index delivery.

Our objective was to provide information on survival and disease progression in human immunodeficiency virus antibody-positive pregnant women undergoing prospective evaluation. After an index delivery, 103 human immunodeficiency virus antibody-positive pregnant women were identified and underwent follow-up for 3 years. The patients were assessed medically and/or gynecologically when hospitalized for a human immunodeficiency virus-related illness or at each follow-up visit. The life-table method was used to estimate the cumulative probabilities of survival and remaining free of acquired immunodeficiency syndrome. Cox's proportional-hazards analyses were used to identify prognostic factors for survival and progression to acquired immunodeficiency syndrome. The majority of human immunodeficiency virus-infected pregnant women were alive 3 years later. Lymphadenopathy syndrome or herpes genitalis was significantly associated with a subsequent diagnosis of acquired immunodeficiency syndrome. Of the 103 original patients, six had acquired immunodeficiency syndrome at the index delivery and acquired immunodeficiency syndrome developed in 24. Approximately 94% of evaluable patients with development of acquired immunodeficiency syndrome had CD4-lymphocyte counts < 200/mm3. The most common opportunistic infection was Pneumocystis carinii pneumonia. Acquired immunodeficiency syndrome and postpartum zidovudine therapy were independent prognostic factors affecting survival. Survival was affected by Centers for Disease Control group status of human immunodeficiency virus infection at the index delivery.


Anti-CD2 monoclonal antibodies prevent spontaneous and adoptive transfer of diabetes in the BB/Wor rat.

We studied the effects of anti-CD2 monoclonal antibodies (MAb) on spontaneous and induced autoimmune diabetes mellitus in diabetes-prone (DP) and diabetes-resistant (DR) BB/Wor rats. In DP rats, all anti-CD2 MAb prevented spontaneous diabetes and the adoptive transfer of diabetes with Con-A--stimulated acute diabetic spleen cells; OX34 prevented Poly I:C induced accelerated onset of diabetes and the adoptive transfer of diabetes with Con-A--stimulated RT6.1+ T cell depleted DR splenocytes. In DP rats, all anti-CD2 MAb except OX53 depleted CD4+ T cells, without depleting natural killer cells or CD8+ T cells. OX34 injected DR rats were profoundly depleted of CD4+ T cells without evidence of decreased CD8+ T cells, but were not protected against the induction of diabetes by RT6.1+ T-cell depletion and Poly I:C injections. We conclude that anti-CD2 MAbs protect against BB/Wor autoimmune diabetes by depleting CD4+ T cells, preventing the activation of effector cells, or by blocking CD2/ligand interaction between effector and target cells.


Multidrug resistance gene (P-glycoprotein) expression in the human fetus.

P-glycoprotein, a transmembrane protein associated with multidrug resistance in cancer cells, is also expressed in normal tissues. To get more insight into the physiologic role of mdr1/P-glycoprotein, we investigated its expression in human fetal tissues after 7 to 38 weeks of gestation by an immunohistochemical technique, using three different monoclonal antibodies, and by a sensitive RNAse protection assay. Expression of mdr1-mRNA could already be demonstrated in the embryonal phase of human development, after 7 weeks of gestation. Comparing the adult with the fetal tissue distribution, differences were found in specific organs, such as adrenal, intestine, respiratory epithelium, and brain capillaries. In the fetal zone cells of the fetal adrenal cortex no staining was observed by immunohistochemistry, whereas the definitive zone showed increasing expression throughout gestation. Prenatal intestine did not show staining of the epithelium, although definite mdr1-mRNA expression was observed in late specimens. Interestingly, respiratory epithelium of main bronchi and pharynx, not expressing P-gp in adults, did stain positive. Expression of P-gp in brain capillaries was not observed before the third trimester of pregnancy, whereas in kidney and liver, mdr1-mRNA expression and staining for P-glycoprotein were detected in early fetal life (11 to 14 weeks). These findings suggest a pivotal role of P-glycoprotein in physiology of various organs already in early phases of human development and may help to identify its physiologic substrates.


Review of pharmacologic treatment of tinnitus.

Recent research on the pharmacologic treatment of tinnitus is reviewed, emphasizing studies in which controls have been used. Several double-blind cross-over studies have found that lidocaine can reduce tinnitus in about 50 to 75 percent of subjects. Unfortunately, it cannot be used clinically because it must be administered intravenously and its effects are very brief. Other drugs have been much less successful. A few controlled studies have found success rates between 33 and 56 percent using oxazepam, clonazepam, sodium amylobarbitone, flunarizine, and eperisone hydrochloride. None of these studies have been replicated, however. Closely controlled studies using specified etiologic subgroups with subjective and objective psychophysical measurements are needed.


C-type natriuretic peptide inhibits growth factor-dependent DNA synthesis in smooth muscle cells.

We have examined the ability of C-type natriuretic peptide (CNP) to interact with guanylate cyclase-coupled natriuretic peptide receptors by measuring its ability to stimulate intracellular guanosine 3',5'-cyclic monophosphate (cGMP) accumulation in cultured bovine aortic endothelial (BAE) and bovine aortic smooth muscle (BASM) cells. Our experiments indicate that CNP is unable to stimulate the production of cGMP in BAE cells, whereas both atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) markedly elevate cGMP levels in these cells (ANP = BNP >> CNP). In contrast, CNP is the most effective of the three peptides with respect to the stimulation of cGMP levels in BASM cells, fetal human vascular smooth muscle cells, and rat A10 cells (CNP >> ANP > BNP), with the maximal level of stimulation being approximately 5- to 10-fold over that observed for ANP. We have also shown that CNP is able to inhibit serum- and growth factor-induced DNA synthesis in BASM cells. Low concentrations of CNP (20 x 10(-9) M) inhibit up to 80% of the [3H]-thymidine incorporation induced by basic fibroblast growth factor, platelet derived growth factor, epidermal growth factor (EGF), and heparin binding EGF-like growth factor. These data indicate that, although CNP has been detected only in the central nervous system and not in the circulation, it may possess multiple effects on vascular tissue.


Ca(2+)-activated K+ channels in pregnant rat myometrium: modulation by a beta-adrenergic agent.

The properties of Ca(2+)-activated K+ currents and channels were characterized in pregnant rat myometrium in whole cell and cell-attached patches and in lipid bilayers. Membrane depolarization of cultured myometrial cells from a holding potential of -50 to +70 mV in 10-mV steps under voltage-clamp conditions (whole cell mode) activated K+ outward currents (IK). At +70 mV, in the presence of 0.2 mM external Ca2+, the amplitude and activation time constant of IK were 15.0 +/- 2.1 microA/microF and 1.5 +/- 0.2 ms, respectively. Addition of 1 microM A23187 to the external solution increased the current from a control value of 16.0 +/- 2.0 to 67.9 +/- 9.1 microA/microF. Charybdotoxin, a blocker of Ca(2+)-activated K (KCa) channels, and a low concentration of tetraethylammonium chloride (TEA; 1 mM) decreased the amplitude of IK by 47 and 62%, respectively. In cell-attached patches from these cells, 1 microM A23187 increased the open time probability of a 143 +/- 6.0 pS K+ channel. Incorporation of plasma membrane vesicles from pregnant myometrium into lipid bilayers resulted in one predominant type of K+ channel. The unitary conductance of the K+ channel was 326 +/- 9.0 pS in symmetrical 450 mM KCl. The channel activation was both voltage and Ca2+ dependent. TEA inhibited the channel activity with a dissociation constant (Kd) of 378 +/- 10 microM at -60 mV or 1,477 +/- 80 microM at +60 mV. The whole cell currents were found to be stimulated by isoproterenol, a beta-adrenergic agent.(ABSTRACT TRUNCATED AT 250 WORDS)


Alpha 1-adrenergic stimulation of Na-H exchange in cardiac myocytes.

The activation of Na-H exchange in adult rat heart myocytes was characterized in response to a phorbol ester (phorbol 12-myristate 13-acetate) and an alpha 1-adrenergic agonist [6-fluoronorepinephrine (6F-NE)]. Transport activation was assessed by determining the initial rate with which intracellular pH (pHi) was returned from an acid pulse and by following changes in steady-state pHi; pHi was determined by a pH-sensitive fluorescent dye. Both agonists shifted the intracellular pH dependence of Na-H exchange by 0.10-0.15 pH units in the alkaline direction. This shift was prevented by the presence of sphingosine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), inhibitors of protein kinase C. The agonists also alkalinized pHi at steady state. The alkalinization by 6F-NE was blocked by prazosin and H-7. This indicates that the adrenergic stimulation of cardiac Na-H exchange is mediated by an alpha 1-adrenergic mechanism and very likely involves the activation of protein kinase C.


Regulation of protein synthesis by modulation of intracellular calcium in rat liver.

The rate of protein synthesis can be modulated in intact cells by varying the concentration and subcellular distribution of intracellular calcium. Because the biochemical reactions required for the pathway of protein synthesis occur in the cytosol of the cell, it might be expected that protein synthesis would be controlled by free cytosolic calcium rather than the sequestered cation. However, a recent report proposed that maintenance of optimal rates of protein synthesis depends on the amount of calcium sequestered in the endoplasmic reticulum rather than free cytosolic calcium (C.O. Brostrom and M. A. Brostrom, Annu. Rev. Physiol. 52: 577-590, 1990). In the present study, rat livers were perfused with buffer containing various compounds previously shown to alter intracellular calcium concentration and distribution in isolated cells. It was found that conditions designed to cause a rise in free cytosolic calcium had no effect on protein synthesis. In contrast, conditions designed to cause depletion of sequestered calcium resulted in an inhibition of protein synthesis characterized by a reduction in peptide-chain initiation relative to elongation. The inhibition of protein synthesis was further localized to a decrease in the activity of eukaryotic initiation factor (eIF) 2B as measured in extracts from perfused livers. The inhibition of eIF-2B activity was associated with a 2.4-fold increase in the proportion of the alpha-subunit of eIF-2 in the phosphorylated form. In summary, the results of the present study support a model whereby mobilization of calcium sequestered in the endoplasmic reticulum results in an inhibition of protein synthesis in rat liver.(ABSTRACT TRUNCATED AT 250 WORDS)


Hypothalamic neuropeptide Y inhibits gastric acid output in rat: role of the autonomic nervous system.

Injection of neuropeptide Y (NPY) into the hypothalamic paraventricular nucleus (PVN) inhibits gastric acid secretion in anesthetized rats. The role of the autonomic nervous system in mediation of this response was investigated. Unilateral microinjection of 200 pmol NPY into the PVN of anesthetized rats inhibited spontaneous and pentagastrin-stimulated gastric acid output. Inhibition was abolished by subdiaphragmatic vagotomy, atropine, and bethanechol but was restored by electrical stimulation of the distal cut end of the vagus in cervically vagotomized rats. Although sympathectomy, phenoxybenzamine, and yohimbine abolished the inhibition, it was not affected by prazosin treatment. Gastric blood flow was not altered by injection of NPY. These results suggest that the antisecretory effect of NPY in the PVN was sympathetically mediated via suppression of gastric vagal cholinergic tone through activation of alpha 2-adrenoceptors.


Pharmacokinetics and organ specific metabolism of glycine-extended and amidated gastrin in sheep.

Glycine (Gly)-extended gastrin has been described as the inactive precursor form of the biologically active amidated gastrin. The ratio of Gly-extended to amidated gastrin is higher in the circulation than in tissue, suggesting either differential secretion and/or metabolism. Although the distribution of the precursor form is similar in tissue and circulation to its amidated product, the significance of measurable levels of precursor peptide in the circulation is unknown. In this study, we have examined the pharmacokinetic properties and organ-specific metabolism of both the Gly-extended and the amidated forms of gastrin-17 (G-17-Gly and G-17-amide) in the conscious sheep. The metabolic clearance rate, half disappearance time, and production rates were similar for both G-17-Gly and G-17-amide. G-17-Gly was extracted across the head, kidney, and lung but not across the gut and liver. Similarly, G-17-amide was extracted across the head, gut, lung, and kidney but not across the liver. G-17-Gly had no biological activity as evidenced by its failure to stimulate somatostatin secretion nor was there any measurable conversion to amidated gastrin in the circulation. We conclude that the presence of G-17-Gly in the circulation is not the result of a slower clearance and that circulating G-17-Gly is not a precursor for circulating gastrin-amide. The results of this study provide important baseline data for understanding the dynamics of the precursor product relationship between G-Gly and G-amide.


Novel sites for expression of an Escherichia coli heat-stable enterotoxin receptor in the developing rat.

Escherichia coli heat-stable enterotoxin (STa) mediates diarrheal disease by binding to and activating an intestinal transmembrane receptor, guanylate cyclase C (GC-C). To test the hypotheses that there was 1) increased perinatal expression of GC-C in rat intestine and 2) GC-C expression and STa binding in extraintestinal tissues of immature rat, we prepared whole cell membranes and total RNA from jejunum, ileum, colon, liver, kidney, heart, lung, brain, testis, and placenta of rats ranging in age from 12 days gestation to adult. Northern analysis demonstrated the presence of a unique 3.8-kb mRNA transcript at all ages in the jejunum, ileum, colon, and, to a lesser degree, in the testis. GC-C was also detected by Northern analysis in liver (from gestational age 18 days through 14 days postnatal) and in placenta. Steady-state mRNA encoding GC-C was not detected by Northern analysis in the other organs examined. GC-C-specific mRNA expression was greatest in the perinatal period in the jejunum, ileum, and liver. Specific binding of 125I-labeled STa was found in each of the tissue membranes in which GC-C mRNA was present; binding was not present in those tissues that had no detectable GC-C mRNA. The existence of GC-C in extraintestinal organs in the rat, and the development changes in GC-C expression support our hypothesis that GC-C, apart from its role as an STa receptor in mediating diarrheal disease, also serves as a receptor for an endogenous ligand.


Reflex cardiovascular response to exercise is modulated by circulating vasopressin.

Peripheral vasopressin (AVP) can act centrally to sensitize the arterial baroreflex and/or peripherally to attenuate regional blood flow by a direct vascular effect. Because plasma concentrations of AVP increase during exercise, this study examined the possibility that AVP is capable of modulating the reflex cardiovascular response to static muscle contraction. Thus, in anesthetized cats, the pressor [mean arterial pressure (MAP)], myocardial contractile (dP/dt), and heart rate responses to 30-45 s of electrically induced static contraction of the hindlimb muscles were compared before and after intravenous injection of the V1 receptor antagonist d[CH2)5Tyr(Me)]-AVP (V1-x, n = 7), V1-x plus the V2 receptor antagonist [d(CH2)5,D-Phe2,Ile4,Arg8,Ala9]vasopressin (V2-x, n = 5), or the ganglionic blocker hexamethonium chloride (n = 5). In three additional cats, the contraction-induced cardiovascular response was monitored before and after injection of V1-x + V2-x and after hexamethonium. Subsequent to treatment with V1-x, the MAP and dP/dt responses to contraction were augmented by 18 +/- 5 and 22 +/- 10%, respectively (P < 0.05). After injection of V1-x + V2-x, the MAP and dP/dt responses were augmented to a similar extent (32 +/- 6 and 40 +/- 17%, respectively; P < 0.05). However, there was no difference in the magnitude of augmentation of these responses between the two conditions. The heart rate response was not altered by either treatment. Ganglionic blockade eliminated the cardiovascular responses to contraction. Last, when the pressor and contractile responses to contraction were initially augmented by administration of V1-x + V2-x, subsequent ganglionic blockade abolished the entire cardiovascular response.(ABSTRACT TRUNCATED AT 250 WORDS)


Clinical and research implications of the diagnosis of dysphoric or mixed mania or hypomania.

The authors reviewed available evidence regarding the status of dysphoric or mixed mania as a distinct clinical state and formulated operational criteria for its diagnosis. Studies of dysphoric mania or hypomania in patients with bipolar disorder were analyzed with regard to clinical characteristics, prevalence, demographic features, course of illness, outcome, family history, associated conditions, biological tests, and response to biological treatment. Although some studies suggest that dysphoric and nondysphoric mania are similar conditions, others suggest that, compared with nondysphoric mania, dysphoric mania may be more severe; more likely to occur in women; more likely to be associated with suicidality, a younger age at onset, a longer duration of illness, higher rates of personal and familial depression, concomitant alcohol or sedative-hypnotic abuse, neuropsychiatric abnormalities, and poorer outcome; more frequently associated with cortisol nonsuppression; and less likely to respond adequately to lithium but perhaps more likely to respond to ECT or anticonvulsants. Substantial evidence suggests that dysphoric mania may be a distinct affective state. Contrary evidence, however, suggests that dysphoric mania may be a form of typical mania, a stage-related or severe form of mania, or a transitional state between mania and depression. Because the evidence may be inconsistent because of varying definitions of dysphoric mania among studies, the authors propose preliminary operational diagnostic criteria for the future study of dysphoric mania.


Implications of the revised surveillance definition: AIDS among New York City drug users.

The Centers for Disease Control (CDC) has proposed revising the AIDS surveillance definition to include any HIV-seropositive person with a CD4 cell count of less than 200 cells per microliter. Based on a study of persons receiving treatment for HIV infection, this new definition would lead to an estimated 50% increase in the number of persons recognized as living with AIDS. Among 440 HIV-seropositive research subjects recruited from drug treatment programs and through street outreach in New York City, 59 met this definition, yet only 25% of those had been reported to the New York City AIDS registry. The new definition, if combined with HIV and T-cell testing at drug treatment and street outreach programs, could thus yield very large increases in the number of injecting drug users meeting the new surveillance definition of AIDS.


The progression of untreated HIV-1 infection prior to AIDS.

Using a case-control study of untreated men, we investigated the physical, mental, and economic effects of human immunodeficiency virus (HIV-1) infection prior to the diagnosis of acquired immunodeficiency syndrome (AIDS). Beginning 2 to 2.5 years prior to AIDS, case subjects reported more of 12 HIV-1 related symptoms and during the year prior to AIDS, at least 30.6 extra days of these symptoms than did control subjects. Within the 6 months preceding AIDS, case subjects' unemployment rose to 9% (P < or = .05) and depression to 34.2% (P < or = .001). At 6 to 12 months and within 6 months before AIDS, 17.1% and 31.5%, respectively, were anemic, while 37.7% and 64.7% had CD4+ counts less than 200 x 10(6)/L. Diagnosing AIDS at CD4+ counts less than 200 x 10(6)/L could significantly reduce pre-AIDS morbidity. Other implications of these findings are discussed.


Immunity to Hantavirus challenge in Meriones unguiculatus induced by vaccinia-vectored viral proteins.

Vaccinia virus recombinants were constructed that incorporated genomic sequences coding for the nucleoprotein (N) and glycoproteins (G1 and G2) of the hantavirus R22 strain isolated from a rat in China, and designated as RNV and RMV9, respectively. The proteins expressed by RNV and RMV9 were identified by radioimmunoprecipitation and indirect immunofluorescence assay using a panel of monoclonal antibodies and polyclonal immune sera, and were found to be antigenically indistinguishable from authentic R22 viral proteins. Both RNV and RMV9 elicited an anti-R22 antibody response in Mongolian gerbils (Meriones unguiculatus) with titers ranging from 6,400 to 12,800 by enzyme-linked immunosorbent assay, but only RMV9 produced neutralizing antibodies to R22 virus (titer 1:200) and Hantaan (HTN) virus (titer 1:20). The ability of these recombinants to protect Mongolian gerbils against challenge with R22 and HTN viruses was examined. The RMV9 recombinant induced a complete protective immune response against challenge with 10(4) plaque-forming units (PFU) of both R22 and HTN viruses, while RNV induced partial protection against a challenge with the homologous R22 virus and the heterologous HTN virus at a dose of 10(3) PFU. Our data show that the common antigenic sites responsible for eliciting a protective response are located mainly on hantavirus glycoproteins, and that the nucleoprotein may also confer partial cross-protection that presumably involves cell-mediated as well as humoral mechanisms.


A comparison of the pharmacodynamics of rocuronium and vecuronium during halothane anaesthesia.

Thirty healthy patients were randomised to receive either a single bolus dose of rocuronium 0.6 mg.kg-1 or vecuronium 0.1 mg.kg-1 during halothane anaesthesia. Onset time, duration 25, duration 75 and train-of-four 70 were measured. The onset of neuromuscular blockade following rocuronium was more rapid than vecuronium (p = 0.0001). All other pharmacodynamic parameters were similar. During the first minute following injection of the neuromuscular blocking agent, the heart rate increased by 36% in the rocuronium group but remained stable in those patients who received vecuronium (p = 0.0008). No adverse effects were noted in either group.


A microtiter plate transglutaminase assay utilizing 5-(biotinamido)pentylamine as substrate.

Transglutaminases belong to an important family of enzymes involved in hemostasis, skin formation, and wound healing. We describe a technique for the measurement of transglutaminase activity using polystyrene microtiter plates coated with N,N'-dimethylcasein. The substrate 5-(biotinamido)pentylamine is covalently incorporated into N,N'-dimethylcasein by transglutaminase in a calcium-dependent reaction. The biotinylated product is detected by streptavidin-alkaline phosphatase and quantitated by measuring the absorbance at 405 nm following the addition of p-nitrophenyl phosphate. The assay is sensitive, specific, and linear at plasma factor XIIIa concentrations between 0.08 and 1.25 micrograms/ml and at purified guinea pig liver transglutaminase concentrations between 0.05 and 0.8 microgram/ml. The intra-assay coefficient of variation is less than 8%. The solid-phase assay was used to quantitate the transglutaminase activity in Escherichia coli extracts expressing recombinant factor XIII A-chains and to analyze factor XIIIa inhibitors. This method will facilitate the analysis of structure-function relationships of the transglutaminases using recombinant DNA methods. Furthermore, screening of natural and synthetic factor XIIIa inhibitors will be expedited by this solid-phase microtiter plate assay.


Detection of neutral endopeptidase-24.11/CD10 by flow cytometry and photomicroscopy using a new fluorescent inhibitor.

Neutral endopeptidase (NEP; E.C. 3.4.24.11) is a mammalian ectopeptidase identified as the common acute lymphoblastic leukemia antigen (CALLA or CD10). In order to investigate its cellular processing and its role in B lymphocyte differentiation, a fluorescent derivative of the mercapto NEP inhibitor thiorphan, N-[fluoresceinyl]-N'-[1-(6-(3-mercapto-2-benzyl-1-oxopropyl) amino-1-hexyl]thiocarbamide (FTI), has been synthesized. The fluorescent characteristics of fluorescein were conserved in FTI after linkage with the thiol NEP inhibitor. FTI inhibited NEP with an IC50 value of 10 nM and a good selectivity compared to that of aminopeptidase N (greater than 100 microM) and angiotensin converting enzyme (32 microM). The FTI probe was shown to detect membrane-bound NEP using photomicroscopy on cultured cells or flow cytometry techniques. Using NEP-expressing MDCK cells and episcopic fluorescence microscopy, a specific labeling was obtained with 100 nM FTI which was completely displaced by 10 microM HACBOGly, a specific and potent inhibitor of NEP. Therefore, FTI can be considered a suitable tool for following cellular NEP traffic. In flow cytometry, the fluorescent probe FTI, used at concentrations as low as 1 nM with Reh6 cells, could be very useful for detecting NEP/CALLA on lymphoid cells. In addition, the recognition of FTI is independent of tissues and species, a major advantage of inhibitors over monoclonal antibodies.


Intramuscularly administered dexmedetomidine attenuates hemodynamic and stress hormone responses to gynecologic laparoscopy.

The hemodynamic and endocrine effects of three different doses of dexmedetomidine (0.6, 1.2, and 2.4 micrograms/kg), oxycodone (0.13 mg/kg), and saline solution, injected intramuscularly 45-60 min before induction of general anesthesia, were compared in a double-blind, randomized study involving 100 women undergoing gynecologic diagnostic laparoscopy. Anesthesia was induced with thiopental (4.5 mg/kg) and maintained with 0.3% end-tidal isoflurane and 70% nitrous oxide in oxygen. Arterial blood pressure and heart rate increased after endotracheal intubation and during laparoscopy in all groups, but the maximal mean arterial pressure after tracheal intubation was lower in the dexmedetomidine 2.4-micrograms/kg group (104 mm Hg [SD 19]) than in the saline solution group (130 mm Hg [SD 12]). Dexmedetomidine (2.4 and 1.2 micrograms/kg) attenuated the maximal heart rate after intubation (84 [SD 11] and 101 beats/min [SD 15], respectively) compared with saline solution (116 beats/min [SD 19]). On the other hand, 40% of the patients in the dexmedetomidine 2.4-micrograms/kg group received atropine in the postanesthesia care unit for bradycardia (heart rate < or = 40 beats/min). Preoperative anxiety and sedation before and after preanesthetic medication were evaluated by the patients with the aid of a profile of mood-state questionnaire; only dexmedetomidine 2.4 micrograms/kg produced significant anxiolysis and sedation. Plasma concentrations of norepinephrine, epinephrine, 3,4-dihydroxyphenylglycol, cortisol, and beta-endorphin increased less in the dexmedetomidine 2.4-micrograms/kg group in response to tracheal intubation and surgery than in the saline solution group.


Dexmedetomidine infusion for maintenance of anesthesia in patients undergoing abdominal hysterectomy.

The usefulness of intravenous dexmedetomidine infusion for maintenance of anesthesia was studied in patients anesthetized with thiopental, fentanyl, nitrous oxide, and oxygen. Isoflurane was added as needed. The study was conducted in two parts, the first of which was an open dose-response study that comprised 14 women undergoing abdominal hysterectomy. After a suitable infusion regimen of dexmedetomidine was determined according to hemodynamic criteria, 20 patients were included in a double-blind, randomized placebo-controlled trial (10 receiving dexmedetomidine, 10 saline solution). Dexmedetomidine was administered as a two-step infusion to rapidly achieve a steady-state plasma concentration. The infusion was started with an initial dose given over 10 min before the induction of anesthesia; at induction the maintenance rate was begun and continued until closure of the abdominal fascia. The infusion regimens of dexmedetomidine tested in the dose-response study ranged from 120 ng.kg-1 x min-1, followed by 6 ng.kg-1 x min-1, to 270 + 13.5 ng.kg-1 x min-1. In the second part of the study, an initial infusion of 170 ng.kg-1 x min-1 was chosen, followed by 10 ng.kg-1 x min-1 for maintenance. Anesthesia was induced with thiopental (4.0 mg/kg) and maintained with isoflurane in 70% nitrous oxide and oxygen. Isoflurane was administered according to predetermined hemodynamic criteria. Dexmedetomidine infusion did not completely abolish the need for isoflurane but diminished its requirement by > 90% (P = 0.02). The heart rate response to endotracheal intubation was significantly blunted.


Tyraminelike action of succinylcholine in the isolated, blood-perfused canine atrium.

The mechanisms of succinylcholine-induced cardiac effects have not been fully elucidated. Accordingly, we studied the effects of succinylcholine on atrial rate and contractile force in the isolated canine atrium perfused with donor blood. The sinus node artery was perfused with heparinized blood from the common carotid artery of the donor dog at a constant pressure of 100 mm Hg. When succinylcholine in a dose range of 30-1000 micrograms was injected directly into the sinus node artery of the isolated atrium, increases in atrial rate and contractile force were observed in a dose-related manner. The atrial rate and contractile force were increased to 10.5% +/- 1.8% (mean +/- SEM) and 56.8% +/- 8.5% above the control values after the administration of 1000 micrograms of succinylcholine, respectively. After treatment with propranolol, the positive chronotropic and inotropic effects of succinylcholine and norepinephrine were significantly suppressed. Hexamethonium or tetrodotoxin pretreatment inhibited the cardiac effects of nicotine but did not modify the succinylcholine-induced cardiac effects. The succinylcholine-induced effects were significantly inhibited by treatment with imipramine, which also suppressed the tyramine-induced effects. We conclude that succinylcholine has cardioexcitatory properties mediated by release of catecholamine due to a tyraminelike action.


Alpha-2A is the predominant alpha-2 adrenergic receptor subtype in human spinal cord.

alpha-2 Adrenergic receptors can be subdivided into four subtypes based on their pharmacologic properties. The subtype of alpha-2 adrenergic receptor present in human spinal cord has not been reported previously. The affinities of nine alpha-2 subtype-selective drugs for the alpha-2 adrenergic receptor in human spinal cord homogenates were determined using [3H]rauwolscine and [3H]RX821002. These drug affinities (pKi values) were highly correlated with those obtained in a tissue or cell line containing only the alpha-2A adrenergic subtype (correlation coefficient of 0.99 and 0.98 for human platelet and HT29 cells, respectively). In contrast, the correlation of pKi values for the human spinal cord with tissues or cell lines containing other adrenergic receptor subtypes was poor. The correlation coefficients for alpha-2B (neonatal rat lung), alpha-2C (OK cell), and alpha-2D (bovine pineal gland) were 0.15, 0.68, and 0.81, respectively. These data suggest that the predominant alpha-2 adrenergic subtype present in human spinal cord is the alpha-2A subtype. Both [3H]rauwolscine and [3H]RX821002 appeared to label a single class of binding sites. The alpha-2 adrenergic receptor density was significantly greater in the sacral region of the cord as compared to either the lumbar or thoracic regions.


Direct coronary and cerebral vascular responses to dexmedetomidine. Significance of endogenous nitric oxide synthesis.

Dexmedetomidine activates alpha 2-adrenergic receptors in the central nervous system and in the peripheral vasculature. In vivo dexmedetomidine has been found to cause alterations in coronary and cerebral blood flows and arterial pressure by stimulation of vascular smooth muscle alpha 2 receptors. The direct vasoconstrictor effects of alpha 2-adrenergic agonists may be opposed by release of endothelium-derived relaxing factor believed to be nitric oxide. A functional endothelium was demonstrated recently in canine coronary collateral vessels. The objective of the current study was to assess the direct effect of dexmedetomidine on isolated canine proximal and distal coronary arteries, coronary collateral vessels, and middle cerebral arteries. Responses were measured in tissue baths in the presence of indomethacin 10(-5) M and in the absence and presence of NG nitro-l-arginine methyl ester (L-NAME), an inhibitor of vascular nitric oxide synthesis. Dexmedetomidine (3 x 10(-8) to 3 x 10(-3.9) M) caused constriction (3.9, 5.5, 72.8, and 2.3% for proximal and distal coronary arteries, middle cerebral arteries, and coronary collateral vessels, respectively, expressed as a percentage of KCl-induced contraction) in all vessels. This constriction was enhanced by the presence of L-NAME in all vessels except cerebral arteries. The selective alpha 2-adrenergic antagonist atipamezole (10(-4) M) abolished the response to low but not high concentrations of dexmedetomidine in middle cerebral arteries, proximal coronary arteries, and coronary collateral vessels.(ABSTRACT TRUNCATED AT 250 WORDS)


High levels of linkage disequilibria between serologically defined class I bovine lymphocyte antigens (BoLA-A) and class II DQB restriction fragment length polymorphism (RFLP) in Norwegian cows.

Serum defined BoLA-A antigens, together with BoLA-DQB RFLP patterns, were determined in 87 almost unrelated Norwegian cattle. Statistical analysis revealed strong linkage disequilibria between these loci at the population level. A total of 13 haplotypes were found to be present at frequencies significantly greater than those predicted on the basis of their component gene frequencies. Among these, the subgroups 1A and 1B of the DQ1 haplotype were found to be closely associated with the class I antigens A11 and w16, respectively. The association between A11 and DQ1A is of particular interest, as two independent studies, one employing class I serology, and the other RFLP analysis of the class II locus DQ, have previously indicated that A11 and DQ1A confer relative susceptibility to mastitis.


Assignment of the HOX2 and HOX3 gene clusters to the bovine chromosome regions 19q17-qter and 5q14-23.

The homeobox 2 (HOX2) and homeobox 3 (HOX3) clusters have been chromosomally assigned in cattle by in situ hybridization. The probes employed were a murine probe for the mapping of HOX2 to 19q17-qter and human probes for the mapping of HOX3 to 5q14-q23. These assignments confirm the chromosomal assignment of two syntenic groups, consisting of loci located on human chromosome 12 (bovine chromosome 5) and the long arm of human chromosome 17 (bovine chromosome 19).


[Consequences and prevention methods of hemodynamic changes during laryngoscopy and intratracheal intubation].

In patients ranked ASA 1, laryngoscopy and intubation lead to an average increase in blood pressure of 40 to 50%, and a 20% increase in heart rate. These changes, which are greatest one minute after intubation, last for 5 to 10 min. They are due to sympathetic and adrenal stimulation, which may also result in some arrhythmias. About half the patient with coronary artery disease experience episodes of myocardial ischaemia during intubation when no specific prevention is undertaken. Among the different means available for this, narcotics seem to have a reliable and constant effect, but they may be responsible for postoperative respiratory depression. The protective effect of fentanyl starts at 2 micrograms.kg-1, and is at a maximum at 8 micrograms.kg-1. Lidocaine is the drug used most. Recent studies have questioned its efficacy. In clinical practice, it is particularly effective in preventing the pressor response to tracheal intubation, whatever its route of administration (intravenous or intratracheal), but not the increase in heart rate. Beta blockers with bradycardic, antihypertensive, antiarrhythmic and antiischaemic properties, have been advocated. As opposed to lidocaine, these agents are more effective in preventing the changes in heart rate than the pressor response. Because of their depressor effect on the myocardium, their place still remains to be defined, especially in the cardiac risk patient. Short-acting beta blockers should be preferred. Nitroglycerin is specifically indicated in coronary artery disease. Other agents, such as clonidine or calcium blockers, seem to be less effective or less convenient in preventing the haemodynamic alterations. In clinical practice, prevention will first rely on a sufficient dose of narcotics. In some cases, nitroglycerin or beta blockers may be used so as to decrease the doses of narcotics, without altering their efficacy; however, the risk of hypotension should be constantly borne in mind. If preventing measures have not been taken, short-acting antihypertensive agents (beta blockers, calcium blockers) should be used in patients who develop major hypertension during laryngoscopy and intubation.


Nedocromil sodium inhibits the airway response to hyperosmolar challenge in patients with asthma.

We studied 16 asthmatic subjects sensitive to changes in airway osmolarity to determine whether nedocromil sodium has any effect on airway narrowing caused by hypertonic saline challenges. Nedocromil sodium (10 mg) or its vehicle was inhaled 10 min before a challenge with ultrasonically nebulized 4.5% NaCl. FEV1 was measured before challenge and 1 min after each challenge period of 0.5, 1, 2, 4, 8, 8 and 8 min. The challenge was stopped when there was a 20% fall in FEV1 from baseline or after the final challenge period. We measured airway sensitivity, that is, the provoking dose of 4.5% NaCl required to induce a 20% reduction in FEV1 (PD20FEV1) and calculated the fold difference in PD20FEV1 after the intervention. After inhaling nedocromil sodium there was a 3.95-fold improvement in PD20 (p < 0.001) when compared with the vehicle day. After pretreatment with nedocromil sodium two of the 16 subjects were completely protected against 4.5% NaCl challenge, and six developed a plateau in their response. We conclude that nedocromil sodium is effective in reducing airway narrowing in response to 4.5% NaCl challenge in asthmatic subjects, and it appears to be unique in its ability to produce a plateau in response to acute administration of a drug before a bronchial challenge.


Increased number of alveolar macrophages expressing adhesion molecules of the leukocyte adhesion molecule family in smoking subjects. Association with cell-binding ability and superoxide anion production.

This study was designed to investigate whether the expression and functional properties of leukocyte adhesion molecules (LeuCAM; CD11/CD18) are altered in human alveolar macrophages (AM) from smokers. Cells were obtained from 38 smokers (S) and 27 nonsmokers (NS) by bronchoalveolar lavage (BAL). Expression of LeuCAM on freshly isolated cells was studied using a sensitive peroxidase-antiperoxidase method with monoclonal antibodies (mAB) against CD11a, CD11b, CD11c, and CD18. The functional properties of the adhesion molecules were studied by measuring in vitro the binding of AM to the intracellular adhesion molecule-1 (ICAM-1) on human umbilical-vein endothelial cells (HUVEC). The influence of LeuCAM on the increased superoxide anion production (O2-) of smoker AM was quantified after blocking the CD18 molecule by a mAB. Compared with nonsmoker AM, significantly more AM from smokers expressed CD11b (p < 0.001), CD11c (p < 0.001), CD18 (p < 0.001), and CD11a (p < 0.004), whereas there was no difference in the expression of other common epitopes of human macrophages such as CD68, CD71, CD45, HLA-DQ, and HLA-DR. The number of AM expressing CD11a, CD11c, and CD18 showed a correlation to the total number of AM obtained by BAL (p < 0.001). Adherence of AM to HUVEC was higher for smoker than for nonsmoker AM (p < 0.05). The increased binding of smoker AM to endothelial cells could be inhibited by treating the HUVEC with a mAB against ICAM-1. The mAB anti-CD18 reduced O2- release from smoker AM by 42 +/- 5% after 120 min.(ABSTRACT TRUNCATED AT 250 WORDS)


[Current diagnostic-therapeutic trends in carcinoids of the papilla of Vater].

Diagnosis and treatment of carcinoid tumor of the ampulla of Vater: case report. The carcinoid tumour of the ampulla of Vater is extremely rare. The authors report one case. Therefore, they dwell upon the problem connected with classifications, symptomatology and diagnosis of these neoplasms which present difficulty to diagnose preoperatively. At last, they reaffirm the primary role of pancreaticoduodenectomy with lymphadenectomy and, if it is possible, the necessity to extirpate the liver metastases.


Effects of orally administered beta-adrenergic blockers and calcium-channel blockers on the intraocular pressure of patients with treated hypertension.

Little attention has been paid to the influence of orally administered antihypertensive drugs on intraocular pressure (IOP). Therefore, we evaluated the effects of oral medications on the IOPs and visual fields of 70 patients with systemic hypertension who had no ocular symptoms and had not visited any eye hospital. In patients with systemic hypertension treated with medication, the IOP value (mean, 18.3 +/- 4.2 mmHg; age range, 63.3 +/- 11.6 years) was significantly higher than in a control group with a similar age range who were not receiving oral medication (mean, 13.7 +/- 2.0 mmHg; age range, 62.5 +/- 7.8 years). In the group in which hypertension was controlled by medication, the IOPs were lower when orally administered beta-adrenergic blockers were given than in those patients with uncontrolled hypertension. In the group to whom calcium-channel blockers were administered orally, the IOPs were not lower. Angiotensin-converting enzyme inhibitors made the visual fields worse. This study suggests a modulating influence of orally administered drugs on the IOP and visual fields, which may be affected by whether or not the patient's blood pressure is controlled.


[Section of spermatic vessels (Fowler-Stephens procedure). A possible treatment for high undescended testis].

Although orchidopexy for an undescended testis is generally a satisfactory operation, high undescended testis is often a problem. Management of such testicles remains controversial and since 1984 the authors have used spermatic vessels division (Fowler Stephens procedure) in 29 cases with satisfactory results. Although the Fowler-Stephens procedure carries a certain risk of testicular atrophy, the results are equivalent to those achieved by the two stage orchidopexy if careful attention is paid to details of the procedure and selection of cases.


[Do calcium inhibitors have any role in secondary prevention of myocardial infarction?].

The value of using calcium blockers in post-infarction secondary prevention is controversial. The HELD meta-analysis (1989) involving 17,759 patients concluded that they made no contribution in this indication (9.8% mortality rate vs 9.3% in the control group). The findings of the DAVIT II study with verapamil demonstrate a significant reduction in the infarction recurrence rate (18% vs 21.6%) in the treatment group. In the patients without heart failure, there was some benefit in terms of reduced mortality (7.7% vs 11.8%). The true contribution of calcium channel inhibitors, relative to that of beta-blockers in post-infarction medication should be analyzed in function of the various infarction sub-groups (no Q-wave, thrombolytic, with or without left ventricular dysfunction), of the calcium channel inhibitor being investigated and of the administration regimen.


Immortalization of fibroblasts from two patients with hereditary retinoblastoma.

Two RB fibroblastic strains from patients with hereditary retinoblastoma (RB), namely, RB80F/250R and RB110F, were transfected with plasmid DNAs encoding SV-40 large T-antigen at passage 31 and 10, respectively, These transfected fibroblasts developed into two immortalized cell lines. RB80F/250R/ori- and RB110F/gpt. RB110F/gpt had a similar doubling time as the parental cells, whereas RB80F/250R/ori- grew more rapidly with a doubling time of 19 hours compared to the parental cells which had a doubling time of 50 hours. The RB80F/250R/ori- cell line was particularly interesting cytogenetically since no normal chromosome 13 was present, although a marker chromosome 13 was found. In contrast, two apparently normal chromosome 13s were present in RB110F/gpt cells, but these cells had a marker chromosome which involved chromosome 14 (14 p+). Both the cell lines also had an abnormal chromosome 1 (1q-). RFLP analysis using the chromosome 13 specific VNTR probe, pTH162, assigned to 13q14.1 showed that the DNA from the RB80F/250R/ori- cells contained only a 6.1kb allelic fragment whereas the DNAs from parental RB80F/250R and RB80F cultures demonstrated both the polymorphic 8.0kb and 6.1kb allelic fragments. However, the RB gene per se was normal at the DNA level. Both cell lines expressed SV-40 large T-antigen together with elevated levels of p53 protein. In addition, levels of RB protein were the same in exponentially growing nontransformed parental cell strains and their immortalized cell lines. However, at confluency the levels of RB protein were greatly reduced in nontransformed cells but not in immortalized cell lines under similar conditions. In future studies using these immortalized cell lines, we shall make an attempt to discern the role of the RB gene and other tumor suppressor genes in the regulation of normal and malignant growth.


Genetic lesion in the carcinogenesis of cervical cancer.

Allelic loss at specific chromosomal loci was demonstrated in carcinoma of the cervix (CaCx) obtained from Hong Kong Chinese by restriction fragment length polymorphism analysis. Altogether 12 patients with CaCx, 7 with cervical intraepithelial neoplasia (CIN) and 7 with normal cervical tissues were studied. Polymorphic DNA markers for chromosome 3 were used and the tumour and constitutional genotypes of the above patients were compared. Loss of heterozygosity (LOH) was found in 10 out of 12 informative cases with CaCx at RAF-1 locus (3p25) and in 10 out of 11 cases at D3S3 (3p14). Further study on patients with cervical intraepithelial neoplasia showed LOH at both 3p25 and 3p14 in four out of five cases. In normal cervical tissues, no LOH was demonstrated at both loci. Our data suggest that the deletion events occurring on the short arm of chromosome 3 at 3p25 and 3p14 are early events in the development of carcinoma of cervix. Since recessive genes have been reported to reside within or close to these 2 loci, important genes may have been lost or inactivated in the genesis of this tumour. Moreover, human papillomavirus (HPV) type 16, 18 or 33 was found in 8/12 of the carcinomas and 4/7 of CIN using Polymerase Chain Reaction and/or Southern Blot hybridization, confirming the close association with human papillomavirus. Whether the observed genetic lesions in the short arm of chromosome 3 in cervical "premalignant" and malignant lesions and their consistent association with high risk HPV represent independent events in the development of carcinoma of cervix will be discussed.


[Testicular ectopy. Current concepts].

Testicular descent is a complex mechanism influenced by hormonal and anatomical factors. Whatever the age of the patient or the descent technique used for either one or both testes, there is a risk of degeneration and sterility counts. Anatomical studies and the results of sperm are important, hence the importance of establishing a precise anatomical and therapeutic classification.


Characterization of beta-adrenergic receptors in DiFi and HT-29 cells.

The beta-adrenergic receptors present in two human colorectal adenocarcinoma cell lines were characterized by measuring specific binding of [125I]-cyanopindolol (CYP). Whole, cultured, DiFi (derived from a familial adenomatous polyposis [FAP] patient) and HT-29 cells were used in radioligand binding assays. Scatchard analysis of specific 125I-CYP binding gave KDS of 38.6 +/- 5.7 pM in DiFi cells and 54 +/- 9.1 pM in HT-29 cells. However, binding site density (Bmax) in the DiFi cells was greater than that in HT-29 cells. In DiFi cells, the kinetically determined KD was similar to that calculated from Scatchard analysis. Studies in DiFi cells of the displacement of specific 125I-CYP binding by nonselective (propranolol), beta 1-selective (metoprolol and atenolol), and beta 2-selective (ICI 118-551) antagonists revealed only a single class of beta 2-adrenergic receptors. This provides the first evidence that colorectal adenocarcinoma cell lines contain beta-adrenergic receptors and shows that only beta 2-adrenergic receptors are present in DiFi cells. Mechanisms possibly affecting beta-adrenergic-receptor expression in such cells are discussed in relation to colon carcinogenesis.