Calmodulin binding of a peptide derived from the regulatory domain of Bordetella pertussis adenylate cyclase

This paper reports the solution conformation and calmodulin binding of a 43-residue peptide from the calmodulin-binding domain of Bordetella pertussis adenylate cyclase. The peptide (P225-267) was synthesized and 15N-labeled at specific amino acids. It binds calmodulin with an equilibrium dissociation constant of 25 nM. Assignment of the NMR spectrum of the free peptide and analysis of the NOE connectivities and secondary shifts of C alpha protons allowed us to identify a 10-amino acid fragment (Arg237 to Arg246) which is in rapid equilibrium between alpha-helical and irregular structures. Titration experiments showed that at substoichiometric molar ratios the two molecules are in intermediate exchange between free and bound conformations. Using 15N-edited methods we assigned a large part of resonances of the labeled residues in the bound peptide. Analysis of the chemical shift differences between free and bound states shows that the fragment Leu240-Ala257 is the most affected by the interaction. The proton spectra of the calmodulin, in the free and complexed states were extensively assigned using homonuclear experiments. Medium- and long-range NOE patterns are consistent with a largely conserved secondary and tertiary structure. The main changes in chemical shift of calmodulin resonances are grouped in six structural regions both in NH2- and COOH-terminal domains. Intermolecular NOE connectivities indicate that the NH2-terminal of the bound peptide fragment is engulfed in the COOH-terminal domain of calmodulin. The interaction geometry appears to be similar to those previously described for myosin light chain kinase or calmodulin kinase II fragments.

Study of the antiviral activity of some new classes of AS-triazine derivatives (preliminary note)

The inhibitory activity exerted by some derivatives with an asymmetrical triazine structure on the multiplication of certain viruses [parainfluenza type 1 Sendai virus, vesicular stomatitis virus, (VSV) herpes simplex type 1 virus (HSV)] was determined: the role of coupling with ribose and that of substitution by halogens on the lateral chain was pointed out.

CD 26--to be or not to be a cofactor for CD 4 receptor of human immunodeficiency viruses

Earlier work has shown that HIV binding to CD 4 is necessary, but apparently not sufficient, for viral entry into cells. Several molecules have been proposed as potential candidates for coreceptors in HIV infection. Remarkable attention and criticism was raised by the report of Hovanessian group from Pasteur Institute, France, which claimed the role of CD 26, an enzyme also known as dipeptidyl peptidase IV, as cofactor in HIV entry and HIV infection. Present review mentions some reports which support or reject this hypothesis.

Considerations about the prophylactic role of T cell vaccination in HIV infection

The AIDS epidemic in Romania has properties that are both common to countries of Eastern Europe and unique to Romania. The unique aspects include the large number of cases in children infected parenterally and a relatively low but steadily increasing number of HIV infected adults. Other groups of children and adults were also exposed at risk to acquire HIV by transfusion with unscreened blood or by multiple parenteral treatments with potentially contaminated needles. Our hypothesis was that a substantial number of people in area of high endemicity was "silently" infected but did not undergo specific immune response or clinical signs. In an attempt to explore the possibility that immunization with autologous proteins (consequence of multiple transfusions) can play a role in the protection from HIV infection or in slowing down the progression of disease, we compared the incidence of autoantibodies (anti-nuclear, smooth muscle and anti-HEp-2) in a group of long survivors children with AIDS, in HIV infected children with rapid evolution and in adults at risk for parenteral acquisition of blood borne viral disease. We analyzed also the incidence of some blood borne viral infections and the presence of anti-HLA antibodies in the same groups of patients. Our results do not support the suggestion that HIV infection or AIDS can be prevented, respectively, delayed by T-cell vaccination.

Preliminary results of HIV screening in sentinel facilities in Romania

In the first months of 1994, 393 patients (random consecutive clinic attenders) from three sentinel clinics were tested for anti-V3 loop antibodies in ELISA with a branched synthetic peptide reproducing eight copies of full V3 sequence. Compared with a commercial HIV 1/2 ELISA kit the sensitivity of anti-V3 assay was 97.6% and the specificity 89.7%. The seroprevalence in women attending prenatal clinic was 7.54% and in children with multiple hospitalization record, 3.82%. Both heterosexual and parenteral transmission through unsafe medical practices fuel actual AIDS epidemic in Romania.

[Seroprevalence of hepatitis C virus among the multiply transfused]

A study was conducted on 61 polytransfused patients, 24 patients submitted to long lasting parenteral treatments, 116 blood donors and 132 controls. Immuno-enzymatic tests were used for detection of antibodies against hepatitis C virus (HCV). They were found in 56 (91.8%) out of the 61 polytransfused patients, in 5 (4.3%) of the donors, in 5 (20.8%) of the patients with multiple treatments and in 5 (3.7%) controls. The VHB markers were detected at variable rates in all investigated groups. The high rate of seropositivity indicates that hepatitis C is becoming an important public health problem in Romania.

[A seroprevalence study of the hepatitis C virus among multiply transfused patients]

A study was conducted on 61 polytransfused patients, 24 patients submitted to long lasting parenteral treatments, 116 blood donors and 132 controls. Immuno-enzymatic tests were used for detection of antibodies against hepatitis C virus (HCV). They were found in 56 (91.8%) out of the 61 polytransfused patients, in 5 (4.3%) of the donors, in 5 (20.8%) of the patients with multiple treatments and in 5 (3.7%) controls. The VHB markers were detected at variable rates in all investigated groups. The high rate of seropositivity indicates that hepatitis C is becoming an important public health problem in Romania.

Protective effect of oral acetylcysteine against the hepatorenal toxicity of carbon tetrachloride potentiated by ethyl alcohol

Considering the well-documented protection of acetylcysteine (AC) in hepatotoxicity related to acetaminophen, we studied the preventive potential of AC against mild hepatotoxicity of CCl4, potentiated with ethyl alcohol (ETH) and the role of tissue glutathione. Rats fed a liquid diet with 30% of energy from ETH, had-intraperitoneal CCl4 administered in three injections, at 7-day intervals. AC was ingested at the level for acetaminophen overdose. ETH markedly potentiated the injury induced by CCl4, as evidenced by higher values of serum alanine aminotransferase (ALT), urinary bile acids (BA), serum creatinine, histological score of liver cell necrosis, mortality and by lower body weights and lower liver glutathione, when compared with CCl4 alone. Protective effect of AC consisted of a lesser hepatocytic necrosis, better body weights and higher liver glutathione. We conclude, that AC favorably modifies liver damage induced by CCl4 and potentiated with ETH. There is a preventive role for AC in subjects who combine ETH overuse with exposure to hepatotoxic xenobiotics, whose toxicity is modified by tissue glutathione.

Induction of chemiluminescent emission in polymorphonuclear leucocytes stimulated by Sendai virus

Sendai virus (SV) stimulates in vitro the chemiluminescent emission (CHL) of human polymorphonuclear leucocytes (LPMN). The kinetics of CHL produced by LPMN depends on the structure of stimulus, the intensity being dependent of the immunological status of the subject. CHL induced by Sendai virus is similar to that given by phorbol-myristate (PMA) as regards the induction of an early maximum. To obtain CHL significant emission, an optimum ratio between LPM concentration and Sendai virus dilution is required. The maximum effect is obtained in a large scale of dilution of Sendai virus ranging from 6,000 to 16,000 uHA.

Calcium blockers in ischemic stroke

The study investigated the evolution of 72-nifedipine treated cases with ischemic stroke. Dipyridamole was administered to 72 controls. Subjects showed clinical improvement, thus calcium blockers can constitute a therapy alternative. A good influence of nifedipine was remarked in blood pressure.

Antiviral activity of some copper complexes of symmetrical triazines

Copper complexes of hydrazones derived from symmetrical triazines inhibit the multiplication of three different types of viruses (Sendai, HSV and VSV) showing as well a scavenger activity on O2- radicals. The results emphasize the antiviral activity of these complexes which have at the same time a O2- radical scavenger activity.

Evolution of ischemic heart disease risk factors in "The Bucharest Multifactorial Preventive Trial of Coronary Heart Disease" after 15-year follow-up

The paper presents the evolution of the levels of smoking, hypercholesterolemia, essential hypertension and obesity in the course of a prophylactic action carried out for 15 years (1971-1986) in a group of 5000 males aged 40-60 years. In the group still available after 15 years of follow up consisting of 2000 subjects, a decrease was obtained in the number of smokers, from 22.3% to 5.6% of hypercholesterolemia from 31.3% to 23.7%. The cumulated incidence of essential hypertension has increased from 15.5% to 36.7% and of obesity from 12.6% to 14.4%. At the same time the incidence of angina pectoris and myocardial infarction increased from 1.1% to 5.3%. For comparison are presented data obtained in a similar control group.

Basal cell carcinoma. A population-based incidence study in Rochester, Minnesota

Population-based annual incidence rates for histologically proved basal cell carcinoma were derived from the records linkage system of the Rochester Epidemiology Program Project. Residents of Rochester, Minnesota, during the years 1976 to 1984, formed the observational cohort. A total of 657 first episodes of basal cell carcinoma were observed. Annual incidence rates per 100,000 persons in the Rochester population, standardized to the 1980 U.S. white population, were 175 for men, 124 for women, and 146 combined. Recurrent or subsequent basal cell carcinoma was observed among 30% of patients during an average of 4.5 years of follow-up; no metastatic lesions occurred. The rates of recurrence were similar after complete excision or treatment with curettage and cauterization in these observational data.

Viral infection correlated with superoxide anion radicals production and natural and synthetic copper complexes

Studies conducted on asymmetric triazine derivatives synthetized at the Chemical and Pharmaceutical Research Institute showed that products S1, S16, S17, S19, S20 and S22 have a remarkable O2- radical scavenger activity. Among these derivatives, the product S1 is the most efficient as an antiviral agent.

[Acute alcoholic hepatitis]

In a group of 1,025 cases of alcoholic liver the authors detected 28 cases (2.73%) of acute alcoholic hepatitis on the basis of the morphologic examination, 75% were males, mean age 45 +/- 18 years. The mean amount of alcohol consumed daily was 106.7 g for a mean duration of 19.78 years. The hepatic lesional substrate was hepatic steatosis and cirrhosis in 7 cases (25%) and steatofibrosis in the other 14 cases (50%). The triggering factors were the abuse of alcohol in 27 cases and a pneumonia in the last case. The disease was characterized by fever, encephalopathy, hepatomegaly, hepatocytolytic-cholestatic syndrome. The evolution was dictated by the gravity of the background hepatic lesional substrate.

Haemodilution therapy in acute ischaemic stroke

The effect of hemodilution was studied in 106 acute ischaemic stroke patients (55 hemodiluted and 51 control subjects). The investigation did not show statistically significant differences between the two groups regarding the mortality rate and the degree of rehabilitation (modified Rankin Scale) but revealed a significant neurologic score (proposed by the Scandinavian Stroke Study Group) in the hemodiluted group. A correlation between the favourable score modification and the degree of hematocrit modification was also observed.

Effects of asymmetrical triazine copper complexes on superoxide radical formation and on the Sendai virus multiplication

The O2- scavenging activity of some ligands of asymmetrical triazine seems to be enhanced when complexed with copper. S1 Cu complex in concentration of 10(-8) M inhibits the multiplication of type 1 (Sendai) parainfluenza virus cultivated on MCA fragments. The possible mechanism of inhibition is discussed.