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Biomedical subjects

J I Santos

Publications and source records attributed to J I Santos.

At least 19 recordsLinked to original sources
PubMed1992

Effects of oral soy phosphatidylcholine on phagocytosis, arachidonate concentrations, and killing by human polymorphonuclear leukocytes.

A dietary supplement of linoleic acid (LA) as soy phosphatidylcholine (PC) or as triglyceride on polymorphonuclear leukocyte (PMNL) functions, arachidonate (AA) concentrations, AA release, and leukotriene B4 (LTB4) generation was studied in normal adults. Study 1: Eight subjects were fed PC (27 g) or placebo for 3 d in a blinded crossover experiment with PMNL assays at baseline and 4, 7, and 14 d. Study 2: Subjects were fed equal quantities of LA as PC (18 g, n = 8), safflower (SF, n = 4), or soybean oil (SY, n = 4) with PMNL assays at baseline and 48 h. Study 1: PC increased PMNL phagocytosis and killing of Candida albicans twofold (P less than 0.001) and PMNL phospholipid AA content threefold (P less than 0.001); AA release after Candida albicans stimulation increased 5.3-fold, correlating with PMNL killing (r = 0.932) and phagocytosis (r = 0.872). Study 2: PC, but not SF or SY, produced changes similar to those of study 1. With PMNL exposure to calcium ionophore A23187 or N-formyl-methionyl-leucyl-phenylalanine, PC increased LTB4 generation. Phospholipid LA, in contrast to triglyceride LA, enhanced PMNL phospholipid AA, phagocytosis, and killing.

Adult↗
PubMed1992

Evidence of preferential female prevalence of HTLV-I associated tropical spastic paraparesis in Bahia-Brazil.

In order to evaluate the prevalence of HTLV-I infection and its association with tropical spastic paraparesis (TSP) in Bahia, a Northeastern State of Brazil, CSF and sera from TSP patients and CSF and/or sera from some selected groups of individuals were studied. The results seem to indicate a higher prevalence of HTLV-I infection in women than men with TSP and among individuals of HIV risk groups. Some alterations of routine analysis of CSF can suggest HTLV-I infection in TSP patients.

Adult↗
PubMed1991

Ceftizoxime disposition in neonates and infants during the first six months of life.

The single-dose pharmacokinetics of ceftizoxime sodium were studied in 52 neonates and infants between 0.1 and 189 days of age. Subjects received ceftizoxime 25 or 50 mg/kg iv over 15-30 minutes. The drug was administered q8-12h for five days to permit tolerance evaluation on repetitive dosing. No differences were observed in ceftizoxime pharmacokinetic parameter estimates relative to dose. However, marked differences were observed in ceftizoxime pharmacokinetic characteristics relative to infant age; ceftizoxime half-life and mean residence time decreased, whereas body clearance increased with infant age. Ceftizoxime volume of distribution remained relatively constant over infant age. No adverse effects associated with ceftizoxime administration were observed. These data suggest that ceftizoxime 50 mg/kg q12h be used for infants less than or equal to 2 weeks of age (less than or equal to 40 weeks postconceptional age) and that 50 mg/kg q8h be administered for older infants.

Aging↗
PubMed1991

[Recurrent respiratory infection in children: its clinical and laboratory evaluation].

Respiratory infections comprise the main cause of medical consultations, and one of two of the first causes of morbidity and mortality in children under five in developing countries. Epidemiological studies have shown that preschool children contract between four and six respiratory infections in the course of a year without this causing any alarm as a deviation from "normality". Yet, the general practitioner and the pediatrician are frequently faced with the dilemma of deciding whether the child who is "always ill" the use of the recurrent infections is, normal or has predisposing conditions to the infections. Among the predisposing conditions for recurrent respiratory infections in children are several host factors, such as immune defense mechanisms and non-immune mechanisms as well as the infections agent and/or the environment. This article is an overview of the clinical and laboratory evaluation findings of children with recurrent respiratory infections.

Child↗
PubMed1990

Comparative efficacies of aztreonam and chloramphenicol in children with typhoid fever.

We compared aztreonam with chloramphenicol in a randomized trial involving the treatment of 36 children with typhoid fever. Eighteen children were randomized to receive aztreonam, 150 mg/kg/day intravenously, and 18 to receive chloramphenicol, 100 mg/kg/day orally. On entry in the study the clinical characteristics of the two treatment groups were comparable. The duration of therapy was 14.9 +/- 3.6 days for the aztreonam group and 12.8 +/- 2.6 days for the chloramphenicol group. The mean duration of fever was 5.9 +/- 3.1 days and 4.05 +/- 2.1 days for aztreonam and chloramphenicol groups respectively (P greater than 0.05). Clinical cure was observed in all patients treated with aztreonam and in 17 of 18 children given chloramphenicol; one patient died in the latter group. There were no relapses in either group. We observed clinical adverse reactions during the treatment with aztreonam in 2 patients. All strains of Salmonella typhi were susceptible to aztreonam, 1 strain was resistant to chloramphenicol and 3 strains were resistant to ampicillin. Aztreonam appears to be a satisfactory alternative to chloramphenicol in cases of typhoid fever caused by resistant strains or when chloramphenicol is contraindicated.

Adolescent↗
PubMed1990

In vitro and in vivo effects of subinhibitory concentrations of clindamycin on experimental Klebsiella pneumoniae sepsis.

We studied the effect of subinhibitory doses of clindamycin on the course of experimental Klebsiella pneumoniae sepsis. Wistar rats were injected intraperitoneally with an inoculum containing 5 x 10(6) colony-forming units of K. pneumoniae resistant to clindamycin (minimum inhibitory concentration greater than 128 micrograms/ml) and then distributed to receive clindamycin 10 mg/kg/day or placebo for 10 days. All animals were bacteremic at 3 h. When the magnitude of bacteremia was compared, no difference was seen during the first 24 h; however, by 72 h the clindamycin-treated group had a significant decrease in the number of colony-forming units per milliliter blood (p less than 0.01). The mortality rate showed a tendency to decrease in the treated group (0%) as compared with the control group (30%). By 120 h, 3 of the 9 (33%) surviving animals from the control group were still bacteremic versus 0 of 11 (0%) in the clindamycin-treated group. These results suggest that subinhibitory clindamycin therapy can improve bacterial clearance and survival during the course of experimental K. pneumoniae sepsis.

Animals↗
PubMed1990

[Nosocomial measles: a proposal for its control in hospitals].

The transmission of measles in medical settings has become increasingly recognized. Due to the lack of information on nosocomial measles in Mexico we performed a 14 year retrospective study at the Hospital Infantil de México Federico Gómez. The objectives of our study were: a) to determine the frequency of the disease in our hospital; b) to determine the association between nutritional status and risk of acquiring nosocomial measles and c) to establish the relationship between nutritional status and complications in morbidity and mortality due to nosocomial measles. Eighty nine children with nosocomial measles were identified. We observed that patients with severe malnutrition had a greater risk of acquiring nosocomial measles developing complication and dying. The most frequent complication was pneumonia.

Child↗
PubMed1990

[Complications in children with measles].

Ongoing immunization campaigns have significantly reduced the incidence of measles. To evaluate the efficacy of vaccination policies, however, it is necessary to analyze disease indicators of mortality and of morbidity such as medical complications and sequelae. We reviewed the hospital experience at Hospital Infantil de Mexico regarding children with measles who necessitated hospitalization between January 1976 and December 1989. During this 14 year period, 176 patients with measles were hospitalized; the majority of the cases corresponded to the period between 1985 and 1989. Fifty five percent of the cases corresponded to children under one year of age. Of those older than 12 months, 81% lacked an immunization history. Eighty percent were from Mexico city or from the neighboring state of Mexico. The mayor complications included: respiratory tract infections such as pneumonia (50.8%), diarrhea (18.2%), and less frequent: laringotracheitis, otitis media, myocarditis and pyodermitis. More than 70% were significantly (grade II or III) malnourished. Twenty three patients died, for a mortality of 13%. The factors more likely related to measles mortality were; age less than two years, undernutrition, and more than two medical complications associated. This report emphasizes that medical complications and mortality are more likely to occur in very young unimmunized, malnourished children.

Child↗
PubMed1990

[Guidelines for vaccination against measles in children].

After the introduction of massive immunization campaigns in Mexico, started in 1973, the measles mortality rate has been reduced in children under five years of age from 2.8% in 1989 to a level of 1.6% in 1985. Two epidemics occurred in 1985 and 1989 with 19,460 and 20,076 reported cases respectively. In the first quarter of 1990 a total of 22,906 cases were reported. The age distribution has been: patients greater than 1 year 26.3%; 1-4 years 24.8%; 5-14 years 35.5% and greater than 15 years 18.2%. The vaccination coverage, between 1987 and 1988, ranges from 34% to 75% in outbreaks studies and in the National Health Survey. The vaccine efficacy in those outbreaks has been estimated from 63% to 89%. The epidemics have been primary related to low vaccination coverage during the last 15 years. The conglomeration of a cumulative number of non vaccinated persons could explain the distribution of cases in all age groups. The strategy based on two doses as has been recommended in the US, is useful in programs addressed to eradicate measles, but the low resources and limited access to health services in rural communities of Mexico have made these control measures in feasible. The measles control in Mexico, must be based in vaccinate each child at the first anniversary, this strategy could be enough to take off the measles epidemics.

Age Factors↗
PubMed1990

[Neonatal meningitis: observations on its etiology, mortality and sequelae].

A retrospective study was carried out on all cases diagnosed with neonatal meningitis at the Hospital Infantil de México Federico Gómez. A rate of 9.6 cases per 1,000 discharged patients was found as well as 6.7% association with sepsis. In 50 of the cases analyzed, an etiologic agent was identified in 23 children; the main bacteria identified were Escherichia coli (24%), Klebsiella pneumoniae (14%), Enterobacter (4%), Proteus mirabilis and Pseudomonas sp (2%), respectively. The mortality rate was 60% and sequelae were seen in 13 of the surviving 20 patients. The unfavorable prognosis of neonates with meningitis forces us to establish an early diagnosis, make every effort to identify the causing agent and try new medications as well as co-adjuvant treatments.

Hospitals, Pediatric↗
PubMed1990

[Educational and research program on diagnosis and treatment of otitis media in Latin America].

Otitis media in Latin America is an important cause of hearing impairment and infectious complications which can be prevented without an inordinate effort or investment of resources. The Latin American Otitis Media Research and Training Program is a multidisciplinary, international project designed to improve the detection an treatment of otitis media in Latin America. Over 200 health care providers have already participated in pilot seminars presented in Brazil, Costa Rica, and Mexico. These sessions were highlighted by audiovisual presentations emphasizing pneumatic otoscopy. We conclude that this focused program of medical education can significantly contribute to improve primary health care in the region.

Adolescent↗
PubMed1990

[Capacity of opsonic recognition of polymorphonuclear neutrophils in malnourished children].

The opsonic recognition capacity of polymorphonuclear neutrophils (PMNs) was evaluated in 19 noninfected children (13 eutrophic and 6 malnourished) and 22 infected children (10 eutrophic and 12 malnourished) by determining the rosette-formation capacity of the PMNs with sheep erythrocytes. After evaluating the percentage of rosette-forming neutrophils (RFN), we did not observe significant differences between the PMNs from eutrophic children and those from noninfected malnourished children (70.2 +/- 5% vs 67 +/- 3% respectively, P greater than 0.5). In contrast, the opsonic recognition capacity of PMNs from children with acute bacterial infections was significantly lower in the eutrophic (54.4 +/- 5.8%, P less than 0.05) and even more accentuated in the malnourished children (42.8 +/- 5%, P less than 0.01) when compared to the noninfected children. These results indicate that the opsonic recognition capacity of the PMNs decreases during bacterial infections. Due to the critical role of the PMNs as a mechanism of defense against infection, the greater decrease of the opsonic recognition capacity of the PMNs observed in infected malnourished children could be yet another explanation for the greater morbidity and mortality from the infectious processes observed in malnourished children.

Adolescent↗
PubMed1989

Antimicrobial susceptibility of selected bacterial enteropathogens in Latin America and worldwide.

We conducted an in vitro susceptibility study of bacterial pathogens to various antimicrobials. Strains of Shigella, Salmonella, Escherichia coli, and Klebsiella pneumoniae collected in the 1960s, 1970s, and 1980s at the Hospital Infantil de Mexico Federico Gomez were tested against ampicillin, chloramphenicol, tetracycline, trimethoprim-sulfamethoxazole, amikacin, gentamicin, and furazolidone. Over the 3-decade period, the resistance of enteropathogens to furazolidone showed the least overall increase. Klebsiella susceptibility to the aminoglycosides decreased during the same period. Worldwide reports of enteropathogenic resistance to antimicrobials are also reviewed. In comparing the results of these worldwide studies with our own, we conclude that there is a need for periodic surveillance and testing of bacterial resistance to antimicrobials.

Anti-Bacterial Agents↗
PubMed1989

Vitamin A supplementation improves macrophage function and bacterial clearance during experimental salmonella infection.

The effects of additional but nontoxic amounts of vitamin A on susceptibility to salmonella infection was studied by comparing rates of bacterial clearance and phagocytosis. Forty-eight male Lewis rats were divided into a treatment group receiving a total of 6000 units of vitamin A palmitate weekly for 5 weeks and a control group was given an equal volume of saline. After completion of the treatment regimen, one-half from each group were infected intraperitoneally with 10(5) Salmonella typhimurium; the other half received intraperitoneal injection of saline. At this time no differences in weight gain were noted and all animals were sacrificed within 2 weeks. At 72 hr after bacterial challenge, all saline-treated control animals displayed bacteremia. Cultures of liver and splenic homogenates were positive in 89 and 100% of infected control animals vs 0 and 44% for treated animals during the first week of infection. Kupffer cell, peritoneal, and splenic macrophages of the vitamin A-treated group had greater phagocytic activity than controls as assessed by the percentage of cells ingesting yeast particles and by the number of particles ingested (phagocytic index). These results suggest that vitamin A in moderate amounts may benefit the host's response to infection by enhancing phagocytic cell function.

Animals↗
PubMed1989

[Impact of infections on mortality in children with cancer].

A study of the role infections play in the death of 29 children with cancer was conducted from 1983 to 1988. An infection was the main cause of death in twelve patients and was associated with hemorrhage in nine. Five of the patients were free of infection at the time of their death. The most frequently found etiological agents found in hemocultures taken while still alive were: Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus viridans, Salmonella enteritidis, Escherichia coli, Enterobacter sp and Candida spp. A retrospective study on the role of infections in the death of children with cancer was conducted. The clinical and autopsy records of 29 children who died between 1983 and 1988 were reviewed. Infection was the main cause of death in twelve patients and was associated with hemorrhage in nine. Five of the patients were free of infection at the time of death. The most frequent etiologic agents found in blood cultures taken while still alive were: Staphylococcus epidermidis.

Adolescent↗