Regionally specific age-dependent decline in alpha 2-adrenoceptors: an autoradiographic study in human brain

The effect of sex, postmortem delay and aging on alpha 2-adrenoceptor binding was studied in tissue sections from several representative regions of the human brain from 21 subjects using [3H]UK-14304 as a ligand. Sex and postmortem delay did not influence the density of alpha 2-receptors. Aging resulted in clear decreases in most forebrain areas examined (n. basalis greater than basal ganglia greater than hypothalamus greater than fronto-temporal cortex greater than hippocampus greater than visual cortex), whereas alpha 2-receptors did not significantly change with age in the amygdala and several infratentorial areas. We conclude that age-related, regionally specific decreases in the density of alpha 2-receptors occur in the human brain. The implications of these findings for age-dependent noradrenergic degeneration are discussed.

The polymerase domain of Streptococcus pneumoniae DNA polymerase I. High expression, purification and characterization

The 3'-terminal two-thirds of the Streptococcus pneumoniae polA gene was cloned in an Escherichia coli genefusion vector with inducible expression. The resulting recombinant plasmid (pSM10) directs the hyperproduction of a polypeptide of 70.6 kDa corresponding to the C-terminal fragment of pneumococcal DNA polymerase I. Induced cells synthesized catalytically active protein to the extent of 7% of the total soluble protein in the cells. The polymerase fragment was purified to greater than 90% homogeneity with a yield of 1.5 mg pure protein/l culture. The protein has DNA polymerase activity, but no exonuclease activity. The enzyme requires a divalent cation (MgCl2 or MnCl2) for polymerization of DNA. Comparison of the mutant and wild-type pneumococcal polymerases shows that the construction did not affect the enzymatic affinity for the various substrates. The mutant protein, like its parent DNA polymerase I, exhibited an intermediate level of activity with primed single-stranded DNA. At high molar ratio of enzyme/DNA substrate, the polymerase fragment catalyzes strand displacement and switching after completing the replication of a primed single-stranded M13 DNA molecule.

Community- and hospital-acquired respiratory syncytial virus infections in Chile

Nasopharyngeal aspirates were obtained on admission from 614 patients younger than 2 years of age who were hospitalized in a ward for acute respiratory infections from June 1988 through October, 1989, in Santiago, Chile. Patients in two rooms were followed during the cold seasons by sampling aspirates every other day during the child's entire hospital stay. Clinical features were recorded daily. Indirect monoclonal immunofluorescent assay and isolation in HEp-2 were used for respiratory syncytial virus (RSV) diagnosis. The mean RSV detection rate was 39% at the time of admission, ranging from 8% in April, 1989, to 62% in July, 1988. During the cold months 43 of 288 (15%) nosocomial RSV cases were detected. Pneumonia and wheezing bronchitis were the principal diagnoses of both groups admitted, whether they were shedding RSV or not. It is concluded that RSV plays a major role in admissions for acute respiratory infections, as well as in nosocomial infections, in Santiago. Because clinical features do not allow one to differentiate viral from bacterial acute respiratory infections, the importance of rapid viral diagnosis is emphasized.

[Etiology of lower respiratory infections in hospitalized infants]

As a contribution to knowledge about the etiology of lower respiratory tract infections (LRI) in infants, 235 patients aged one year or less admitted to a children's hospital at northern metropolitan area of Santiago, Chile along years 1987 throughout 1989 with radiologically confirmed diagnosis were studied. Infants were eligible only if their symptoms lasted for not more than five days and their hospital stay was less than two days. Controls consisted on 74 healthy infants. A search for presumptive etiology was done by means of usual bacteriological procedures (pharyngeal swabs and blood cultures), plus latex test for type b Haemophilus influenzae (Hib) and Streptococcus pneumoniae (SP) in concentrated urine specimens; indirect immunofluorescence (IF) for specific Chlamydia trachomatis (CT) IgM; serological tests, isolation and IF in pharyngeal aspirates for syncytial respiratory virus (SRV), influenza, parainfluenzae and adenoviruses were also used. Evidence of viral infection was detected from 135/235 (57.5%) of cases and 21/74 (28.3%) controls, SRV being the most common. From 18/119 and 2/119 studied patients Hib and SP antigens were respectively detected, but urinary antigens were also present in 6/24 controls, raising questions about this test's specificity. IF titers of 1:32 or higher for CT were found in 5/80 patients, all younger than 5 months. It was possible to perform the whole set of available methods in 80 patients, in 70% of which some evidence of a known etiologic agent was found. Serology alone gave etiological clues in only 30% of these cases and usual microbiological cultures of throat swabs and blood from none of them. No combinations of age, fever, respiratory rate, apnea, bronchial obstructive syndrome, white blood cell counts over 15,000 or of band forms over 500 per cu mm, erythrocyte sedimentation rates, reactive C protein and x-ray findings allowed differential diagnosis between presumptive bacterial or viral etiology, except in one case of an infant presenting with pleural effusion and positive antigenuria for Hib.

Metabolic responses of isolated hepatocytes to adenosine; dependence on external calcium

The role of cyclic-adenosine monophosphate (cAMP) and calcium (Ca2+) in the metabolic responses to adenosine was studied in isolated hepatocytes from fed rats. In the presence of 1.2 mM Ca but not in the absence of Ca2+, adenosine stimulated ureagenesis without increasing cAMP. Adenosine inhibited the glucagon mediated increase in cAMP. Adenosine increased free cytoplasmic Ca2+ provided that cells were incubated in the presence of external Ca2+. In the absence of added Ca2+ adenosine did not stimulate ureagenesis or the movements of Ca2+. It is suggested that, in the liver cell, Ca2+ may be a second messenger for adenosine.

[Evaluation of traditional medicine: effects of Cajanus cajan L. and of Cassia fistula L. on carbohydrate metabolism in mice]

The authors report the results of pharmacologic evaluation of two medicinal plants: Cajanus cajan (L.) Millsp and Cassia fistula, which are used in Panamanian folk medicine for the treatment of diabetes. It was found that the aqueous fraction of the leaves and stems of C. cajan did not produce any hypo blood sugar effect in normoglycemic mice; instead, it produced a hyperglycemia with doses of 500 mg/kg and 1000 mg/kg (p less than 0.001). Only with a dose of 300 mg/kg a short lived decrease in the glycemia was seen at one hour. On the contrary, the folk use of the leaves of C. fistula for diabetes seems to have some correlation with the popular frek use. The aqueous fraction produced a significant decrease in the glycemia (p less than 0.001) at 4 and 24 hours with doses of 300 and 500 mg/kg, and at one and four hours after the dose of 1000 mg/kg (p less than 0.001). In the glucose tolerance test, the aqueous fraction of C. cajan produced a significant and short lasting decrease (p less than 0.05) with the dose of 300 mg/kg, while the dose of 500 mg/kg did at 0.25, 0.5 and 1 hour (p less than 0.01). The 1000 mg/kg dose produced a significant increase in glucose tolerance at 1 and 2 hours (p less than 0.05). The aqueous fraction of C. fistula produced a significant decrease (p less than 0.05) with the dose of 500 mg/kg at 0.25 and 0.5 hours. The 1000 mg/kg dose produced a significant increase (p less than 0.001) at 0.25 and 2 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

[Etiology of lower acute respiratory infections in hospitalized infants. 3. Investigation of Chlamydia trachomatis]

Five infants with Chlamydia trachomatis associated pneumonia are analyzed. They were diagnosed out of 80 infants admitted to the hospital with pneumonia whose etiology was studied for virus, bacteria and Chlamydia trachomatis. Serum IgM antibodies to Chlamydia tr. were measured by indirect immunofluorescence (IIF), which is considered to be specific in high titers (1 greater than or equal to 32). The five cases represented 10.4% of infants studied younger than six months. One child was born by cesarean section suggesting the possibility of other non oculogenital still undefined mechanism of transmission. Clinical symptoms and laboratory findings were characteristics of those described in Chlamydia tr. pneumonia. Chlamydia trachomatis must be considered an etiologic agent in infantile pneumonia specially in the first six months of life. The high specificity and sensitivity of the IFF makes this serologic test the best non-invasive method for diagnosis of Chlamydia tr. pneumonia currently available.

Treatment of recurrent common warts with one low dose of intralesional natural human leukocyte interferon alpha

Nine patients with recurrent and long lasting common warts were treated with intralesional Hu-IFN-alpha. The schedule was a single dose per wart, ranged between 10(5) and 2 x 10(5) IU. Placebo was also administered in 3 of these patients. Complete remission was observed in 7 of the 9 patients. The pattern of warts involution and the possible interferon mechanism of action are discussed. A significant pain relief, produced by interferon injection was observed in the patients with plantar warts and in one patient with subungueal wart.

[Calculation of the mitral valve area using Hatle's method. Effect of the preload change induced by nitrates]

The aim of the present study was to assess the effect of changes in preload induced by nitrates on calculated mitral valve area by Doppler pressure half-time. Forty patients (mean age 51 +/- 10 years), 23 with mitral stenosis, ten with mechanical prosthesis and seven with bioprosthesis were studied by Doppler echocardiography. Twelve were in sinus rhythm and 28 had atrial fibrillation. Mitral valve area by Doppler pressure half-time, peak and mean mitral gradient and pulmonary artery systolic pressure were measured before and after isosorbide dinitrate (5 mg) or nitroglycerin (0.4 mg). The nitrates produced a significant reduction of pre-load in total group (p less than 0.001) but did not change the mitral valve area (1.9 +/- 0.8 to 1.9 +/- 0.8). The subsets of patients with size valvular area (greater than 2 cm2, less than 2 cm2, less than 1.5 cm2, mechanical prosthesis, bioprosthesis, sinus rhythm and atrial fibrillation) had an insignificant change in mitral valve area after administration of nitrates. We conclude that the mitral valve area by Doppler pressure half-time method do not modify in different conditions of preload. These findings remain in patients with prosthesis, different sizes of mitral valve area and atrial fibrillation.

Cardiac surgery at San Pablo Heart Institute: a preliminary report of the first year experience

A series of 341 patients undergoing cardiac surgery, of which 276 underwent coronary artery bypass grafting (CABG) and 37 underwent valve replacement, is presented herein. Results of mortality and morbidity are shown, discussed and compared to that of other institutions, and found favorable. These patients represent our first year of experience at the San Pablo Heart Institute.

[Systolic stress in mitral stenosis]

Left ventricular systolic stress was studied in nineteen patients with mitral stenosis, twelve in sinus rhythm and seven in atrial fibrillation. Left ventricular dimensions and volumes and septal and posterior wall thickness were measured by means of M and two bidimensional echocardiography at rest and during isometric exercise. Expulsive indices: fractional shortening, ejection fraction and mean circumferential shortening rate were calculated. Ventricular mass, meridional stress and several end-systolic stress or pressure/volume relationships were estimated. Patients with atrial fibrillation were older and had systolic dysfunction: greater end-systolic volumes and depression of both expulsive fractions and some of the end-systolic indices. Preload and wall thickness were normal. Patients with atrial fibrillation showed higher ventricular stress as a consequence of greater ventricular dimensions. Ejection fraction correlates directly with mitral valve area and inversely with inotropic state and heart rate. It is concluded that systolic dysfunction in mitral stenosis is multifactorial. The most important determinants of the abnormality are heart rate and inotropic state. The study did not show any primary abnormality of afterload or hypotrophy of the left ventricle.

[Etiology of acute infections of the lower respiratory tract in hospitalized infants: bacterial antigens]

Demonstration of bacterial antigens in biological fluids has been used for early detection of bacterial infections. Recent evidence suggests that higher detection rates of these antigens can be obtained from concentrated urine than from serum samples of patients. Evidence of bacterial infection by antigen detection was looked for from 50 fold concentrated urine samples by means of an ultrafilter system (Minicom) and latex agglutination for Haemophilus influenzae B (HiB) and Streptococcus pneumoniae (Sp) in three groups of patients. Group A (Positive controls), included 7 patients whose blood culture were positive for HiB (n = 5) and Sp (n = 2). Group B (Healthy controls) involved 16 children without clinical and laboratory signs of infection, coming from ambulatory well baby clinics and surgical wards, and group C was formed by 77 patients with negative blood cultures but with clinical and X ray evidence of lower respiratory tract infection. The corresponding antigen was demonstrated in urine samples from all group A patients. Three group B subjects gave positive results for HiB antigen. HiB antigen was detected from 10 and Sp antigen from 2 group C patients. These results suggest that the search for bacterial antigens in urine would be useful for etiological diagnosis and management of patients with bacterial pneumoniae. There is no definite explanation for the finding of HiB antigen in urine from apparently healthy children but the possibility of previous or actual asymptomatic infections must be taken into account.

Immunomodulation by indoleamines: serotonin and melatonin action on DNA and interferon-gamma synthesis by human peripheral blood mononuclear cells

Different concentrations of indoleamines, serotonin and melatonin, inhibited phytohemagglutinin stimulated DNA synthesis. Thus, 10(-3) to 10(-4) M of either indoleamine acted at the optimal phytohemagglutinin concentration, while 10(-3) to 10(-7) M acted at suboptimal phytohemagglutinin levels. The serotonin effect was reversed by the serotonergic S1-S2 receptor antagonist methysergide but not by the S2 antagonist ketanserin. This indicates that only the S1 receptor is involved in the inhibitory effect. Inhibition of lymphoproliferation by indoleamines was also exerted on pokeweed mitogen and protein A from Staphylococcus aureus stimulations. Serotonin and melatonin also inhibited phytohemagglutinin and protein A from Staphylococcus aureus induction of interferon-gamma synthesis. The initial uptake of Ca2+ was not affected by indoleamines, suggesting that it is not the mechanism of their inhibitory effects. As interferon-gamma induced tryptophan uptake by T lymphocyte- and macrophage-depleted populations, and tryptophan is the metabolic precursor of serotonin and melatonin, a new immunoregulatory circuit is postulated.

A prospective, randomized study comparing highly selective vagotomy and extended highly selective vagotomy in patients with duodenal ulcer

The recurrence rate of duodenal ulcer after highly selective vagotomy is nearly 10 percent. To diminish this percentage, extended highly selective vagotomy with sectioning the gastroepiploic nerves has been proposed in order to reduce postoperative gastric acid secretion. We have prospectively compared the decrease in gastric acid secretion through measurement of basal acid output, maximal acid output, and peak acid output in patients who underwent highly selective vagotomy or extended highly selective vagotomy. No significant differences in postoperative gastric acid secretion were found and, therefore, no changes in the probability of postoperative recurrence of duodenal ulcer were seen.

Enzyme-linked immunosorbent assay for diagnosis of brucellosis

The performance of an ELISA for detection of total antibodies to Brucella spp. was compared with that of the Rose Bengal, standard agglutination and Coombs test in the diagnosis of brucellosis. Sera tested were from 208 patients from whom Brucella melitensis had been isolated, 177 patients with significant results in at least two conventional tests, and 107 patients with fever from whom no Brucella spp. had been isolated and in whom all conventional tests were negative. ELISA was the most sensitive test (97%), showing greater specificity (96%) and good predictive positive and negative values (98% and 94% respectively). ELISA was the only positive test in 6% of patients in whom brucellosis had been confirmed by culture.

Evaluation of four enrichment media for isolation of Campylobacter jejuni

Diarrheal stool specimens were inoculated into the following media: alkaline peptone water (APW), Bruce-Zochowsky medium (BZ), Campylobacter enrichment broth (CEB), Campy-thio broth (CT), and Skirrow blood-agar (SK) plate. All media were incubated at 42 degrees C in microaerophilic conditions for 24 h. Afterwards, a new SK plate was inoculated from every liquid medium. Campylobacter jejuni was isolated from 43 of the 259 specimens when CT was used, from 45 when APW was used, from 46 when BZ was used, and from 46 when CEB was used; these totals include specimens that grew after enrichment only, on SK plates only, and both after enrichment and on SK plates. No significant differences were found between the isolates obtained with and without enrichment procedures.

Comparative efficacy of seven selective media for isolating Campylobacter jejuni

Diarrheal stools from 263 patients were inoculated on seven selective media: Butzler selective medium, Blaser medium, Skirrow blood agar, Preston campylobacter selective medium, Preston campylobacter blood-free medium, Butzler Virion medium, and modified Preston medium (with amphotericin B [2 mg/liter]). A similar number of Campylobacter jejuni strains were isolated from all the media studied; nevertheless, the presence of competing fecal flora (FF) made the detection of suspect colonies difficult. Preston campylobacter blood-free medium with cefoperazone yielded the greatest number of C. jejuni isolations, and contaminating FF grew in only 9% of the plates showing C. jejuni growth; all the other media allowed the abundant growth of other FF, regardless of whether C. jejuni was isolated from them or not.

Annular apodizers for low sensitivity to defocus and to spherical aberration

We propose a method for designing apodizers that increase the depth of focus and reduce the influence of spherical aberration. These two properties are explicitly manifested in computer-generated pictures and values of the Strehl ratio for variable spherical aberration.

[Treatment of congenital chloride diarrhea with prostaglandin synthetase inhibitor (author's transl)]

In a patient with congenital chloride diarrhea, the hyperreninemia, hyperaldosteronism, hypokaliemia and hypokaliuria diminished during treatment with prostaglandin synthetase inhibitor. These findings suggest that probably prostaglandins stimulate renin-aldosterone system in congenital chloride diarrhea.

[Recurrent obstructive bronchitis in infants]

The study comprised 458 infants complaining of recurrent obstructive bronchitis from the clinical, chest X-rays and gastroesophageal reflux investigation view points. Spontaneous radiological reflux was found in 49.1% of the patients, although a history of vomiting was present only in 26.6%. In infants with positive radiological reflux, manometrics showed a shorter gastroesophageal sphincter and with lesser pressures than a group of normal infants. With medical treatment of the reflux, remission of the respiratory symptoms was seen in 63.5% of the patients. In a group of infants treated, control X-rays, and manometrics were practiced at the end of the medical treatment showing significant improvement of pressure and length of the gastroesophageal sphincter. The long-term follow-up in infants showing failure of the medical treatment, bronchial asthma appeared in 56.6%.