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Biomedical subjects

W J Rodriguez

Publications and source records attributed to W J Rodriguez.

At least 109 records · Page 6Linked to original sources
PubMed1979

Cefaclor in the treatment of susceptible infections in infants and children.

Cefaclor is a new oral cephalosporin with in vitro activity against a wide variety of organisms including S. aureus, S. pneumoniae, S. pyogenes and H. influenzae (including ampicillin-resistant strains). Seventy-nine patients ranging in age from 2 months to 14 years with soft tissue infections (17 cases), otitis media (17), and streptococcal pharyngitis (45) were studied. They received cefaclor orally at a dose of 40 mg/kg per day in three or four divided doses for a minimum of five days. Results were generally good with favourable clinical and bacteriological responses obtained in 90% of cases. Most patients became afebrile within 48 hours after starting cefaclor. Two patients with H. influenzae cellulitis and bacteraemia defervesced within 24 hours and their blood cultures became negative promptly. Hepatic, renal and haematopoietic studies showed no adverse reactions except for an occasional increase in the eosinophil count with no clinical counterpart of hypersensitivity. Pharmacokinetic studies revealed that following a 10 mg/kg oral dose, peak serum levels of 8 micrograms/ml were observed at one hour, followed by a rather rapid tapering off so that at the end of four hours, virtually no cefaclor was detectable in serum.

Adolescent↗
PubMed1978

Epidemiology of human rotavirus Types 1 and 2 as studied by enzyme-linked immunosorbent assay.

To determine the relative importance of two known serotypes of human rotavirus, we developed an enzyme-linked immunosorbent assay to differentiate serotype-specific rotavirus antigen and antibody. Using this technic, we studied the epidemiology of the two serotypes in acute gastroenteritis. Seventy-seven per cent of 414 rotavirus isolates were Type 2, and the remainder were Type 1. The serotype distribution was similar in specimens from children in Washington, D.C., and other parts of the world. Sero-epidemiologic studies revealed that most children living in the Washington, D.C., area acquired antibody to both types by the age of two years. An analysis of children who were reinfected indicated that sequential infections usually involved different serotypes and that illness caused by one serotype did not provide resistance to illness caused by the other serotype. These results suggest that, to be completely effective, a vaccine must provide resistance to both serotypes.

Antibodies, Viral↗
PubMed1978

Clinical and laboratory evaluation of cefamandole in infants and children.

Fifty-three infants and children, aged three months to 15 years, were treated with an average daily dose of 100 mg of cefamandole/kg intravenously. Of these patients, 47 had soft tissue cellulitis and six had pneumonia. Primary pathogens, including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Haemophilus influenzae, were isolated from 43 of the 53 patients. Bacteremia was documented in six of the 53 patients. A satisfactory clinical and bacteriologic response to cefamandole was achieved in all cases except on (98%). The only treatment failure occurred in an infant with both periorbital cellulitis and bacteremia due to H. influenzae who developed meningitis while receiving cefamandole; no extravasation of the drug across the blood-brain barrier could be detected in spite of inflamed meninges. In general, the only aberrant effects of cefamandole were the appearance of eosinophilia in 28% of patients and a positive indirect Cooms' test without hemolysis in one patient. Cefamandole showed excellent in vitro activity against 87 ampicillin-resistant strains of H. influenzae. Because it has greater activity than any of the other cephalosporins against this important pediatric pathogen, cefamandole may have particular pertinence in the treatment of infections in infants and young children.

Adolescent↗
PubMed1978

Differential binding of penicillin by membrane fractions from penicillin-susceptible and -resistant gonococci.

An inverse relationship between binding of [(14)C]penicillin to cells of Neisseria gonorrhoeae and the minimal inhibitory concentration of penicillin was recently reported by us. Herein we report a similar relationship in binding by cytoplasmic membranes derived from 10 strains of gonococci. Membranes were extracted after Braun homogenization and differential centrifugation of the resulting extracts. Membranes derived from penicillin-susceptible cells bound 140 to 200 nmol of [(14)C]penicillin per g of enzyme, whereas relatively nonsusceptible strains bound 18 to 59 nmol. Binding by cell walls was only a small fraction of the total binding and probably represents contamination of the walls by membrane. Pretreatment of cell membranes with either unlabeled penicillin or cephalothin prior to [(14)C]penicillin exposure markedly decreased (14)C binding. Slab gel electrophoresis of membranes revealed 13 protein bands, 8 of which were labeled.

Cell Membrane↗
PubMed1977

Acute purulent otitis media in children older than 5 years. Incidence of Haemophilus as a causative organism.

It is generally believed that Haemophilus influenzae is not commonly a causative agent of otitis media in children older than 5 years of age. We recently studied cases of 58 children, aged from 5 to 9 years, who had acute otitis media. Haemophilus species were the causative agents in 36% of cases. This high incidence of Haemophilus isolation from the middle ear exudate of these children has important therapeutic implications; antibiotics effective against H influenzae should be employed when dealing with otitis media in this older age group.

Acute Disease↗
PubMed1977

Human reovirus-like agent infection. Occurrence in adult contacts of pediatric patients with gastroenteritis.

Sixty-four adult family contacts of 61 young patients with gastroenteritis were included in a study for evidence of concurrent infection with the human reovirus-like agent (HRVLA) of infantile diarrhea. Evidence of infection was detected in 26 (41%) of the adult contacts. The HRVLA infection occurred significantly more often among adult contacts of pediatric patients infected with HRVLA (55%) than among contacts of young patients not infected with the agent (17%). Mild cases of gastroenteritis developed in only three of the contacts infected with HRVLA.

Adolescent↗
PubMed1977

Clinical features of acute gastroenteritis associated with human reovirus-like agent in infants and young children.

Between January, 1974, and June, 1975, infection with a human reovirus-like agent was detected in 47% of 152 infants and children hospitalized with acute gastroenteritis. Certain epidemiologic, clinical, and laboratory findings appear to be helpful in distinguishing gastroenteritis due to HRVLA from other causes in those children sick enough to require hospitalization. Age: 76% of infants and children seven through 12 months of age and 76% of those 13 through 24 months of age had infection with the HRVLA, whereas such infection was found in only 21% of infants under six months of age and 23% of children 25 through 60 months of age. Time of Year: 61% of patients studied during the cooler months had HRVLA infection and such infection was not found from June to October. Frequency of vomiting and dehydration: Twice as many patients infected with HRVLA as those who were not had vomiting (92%) and significant dehydration (83%).

Acute Disease↗
PubMed1977

Cerebrospinal fluid lactic acid levels in meningitis.

Measurement of cerebrospinal fluid lactic acid by gas liquid chromatography and by an enzymatic Monotest lactate test was evaluated for the early detection of bacterial meningitis in 396 patients. Spinal fluid specimens from 62/62 patients with a bacterial or mycoplasma etiology yielded lactate levels greater than the upper limits of normal, whereas specimens from 334 patients with no bacterial involvement gave values within the normal range. The duration of elevated CSF lactate values coincided with the clinical response to therapy. When considered along with the history and physical examination of the patient, determination of lactic acid proved to be a rapid and reliable diagnostic test for the early detection of untreated as well as partially treated pyogenic meningitis.

Adolescent↗
PubMed1976

Human reovirus-like agent as the major pathogen associated with "winter" gastroenteritis in hospitalized infants and young children.

We found a human reovirus-like agent in the stools of 42 per cent of 143 infants and young children hospitalized with acute gastroenteritis between January, 1974, and June, 1975. Half the patients studied by electron microscopy and serologic technics had evidence of infection with the agent. The infection had a seasonal pattern: 59 per cent of those admitted during the cooler months (November to April) shed the agent, with a peak of 78 per cent in December, 1974, and January, 1975, combined. None of the patients admitted during the warmer months (May to October) shed the agent. None of 275 Escherichia coli isolates from 32 patients with diarrhea produced heat-labile enterotoxin, whereas 17 of the 32 had evidence of infection with the reovirus-like agent. In addition, 14 of 40 parents of 37 patients with diarrhea associated with the reovirus-like agent were also infected, but most infectious were inapparent. This agent appears to be the major cause of diarrheal illness in the young during the cooler months.

Acute Disease↗
PubMed1976

Recent advances in the aetiology of viral gastroenteritis.

Studies with the human reovirus-like (HRVL) agnet, also designated rotavirus and duovirus, have revealed that it is a major aetiological agent of diarrhoea of infants and young children in many parts of the world. In a study of patients admitted with a diarrhoeal illness to the Children's Hospital of the District of Columbia in the United States from January 1974 to June 1975, it was found that half of the patients studied by both virus shedding (by electron microscopy) and serological (complement-fixation) techniques demonstrated evidence of infection with the HRVL agent. The temporal distribution of infections with the HRVL agent followed a seasonal pattern with this agent being shed exclusively by patients admitted during the cooler months of the year. Electron microscopic examination of stools was as efficient as serological methods for detecting infection with the HRVL agent. We also initiated studies to determine the possible mode of transmission of the HRVL agent by studying contacts of hospitalized patients. We found that 35% parents of patients with HRVL infections were also infected with the HRVL agent. Serological studies revealed that the HRVL agent was antigenically related to the Nebraska Calf Diarrhoea Virus, the epizootic diarrhoea of infant mice virus, the SA-11 virus, and the "O" agent.

Animals↗
PubMed1974

Reoviruslike agent in stools: association with infantile diarrhea and development of serologic tests.

Reoviruslike particles were visualized by electron microscopy in stool filtrates prepared from stools of infants and young children with severe acute gastroenteritis. Patients who had such particles in their stools and whose paired acute and convalescent serums were tested developed an antibody response to the reoviruslike agent, which was measured by immune electron microscopy and by complement fixation. The reoviruslike agent was antigenically related to the epizootic diarrhea of infant mice virus and the Nebraska calf diarrhea virus.

Animals↗
PubMedDate not supplied

Approaches to immunization of infants and young children against gastroenteritis due to rotaviruses.

Recent studies have shown that in developed countries rotaviruses are the single most important etiologic agents of acute gastroenteritis that requires hospitalization of infants and young children. Although deaths from gastroenteritis are, in general, infrequent in the developed countries, an effective rotavirus vaccine would clearly be of benefit to reduce the heavy toll of morbidity from gastroenteritis due to rotavirus. In the developing countries the impact of diarrheal diseases is staggering. It was recently estimated that in Asia, Africa, and Latin-America during a one-year period there would be 3.5 billion cases of diarrhea and 5-10 million deaths associated with diarrhea; in addition, diarrhea was ranked first in freqency in the categories of disease and mortality. In the developing countries rotaviruses are known to cause diarrhea, but their relative role in this high mortality rate is not yet known. epidemiologic data indicate that development of an effective rotavirus vaccine would reduce morbidity, and they suggest that a vaccine would also reduce a portion of the mortality from diarrheal disease. The prospects and approaches for the development of an effective rotavirus vaccine are presented. The recent successful propagation of rotavirus type 2 in cell culture represents an important step in this regard. In addition, the antigenic relation between human and animal strains offers another possible approach. The need for a live attenuated vaccine is indicated by the prime role played by local intestinal immunity in resistance to rotavirus disease.

Animals↗
PubMedDate not supplied

Trimethoprim-sulfamethoxazole in the treatment of otitis media caused by ampicillin-resistant strains of Haemophilus influenzae.

Trimethoprim-sulfamethoxazole (TMP-SMZ) was successful treatment for 93% of cases of acute otitis media caused by ampicillin-resistant Haemophilus influenzae studied. All 15 children in this study had symptoms of otitis media that were unrelieved by a course of ampicillin therapy, but 14 of them responded promptly to a 10-day course of TMP-SMZ. Potentially invasive type b strains of H. influenzae were isolated in cultures of the middle ear exudate of three children, all of whom responded well to TMP-SMZ therapy. The middle ear isolates of H. influenzae were sensitive in vitro to TMP-SMZ. It is concluded that TMP-SMZ is effective and convenient for the treatment of otitis media caused by ampicillin-resistant H. influenzae.

Ampicillin↗
PubMedDate not supplied

Chlamydia trachomatis in otitis media in children.

Thirty-one middle ear fluids were obtained for Chlamydia trachomatis culture by tympanocentesis or myringotomy in 26 children and acute otitis media (AOM) or persistent otitis media with effusion (POME). The study population included 12 patients with AOM and 14 patients with POME. C. trachomatis was recovered from the middle ear fluid of two patients (16%) with AOM and from one patient (7%) with POME. Sixty external auditory canal specimens from 30 normal children were cultured. None was positive for C. trachomatis. Because our study population was small the true significance of this organism as a pathogen in ADM or POME is impossible to assess at this time.

Acute Disease↗
PubMedDate not supplied

Trimethoprim-sulfamethoxazole treatment of persistent otitis media with effusion.

Persistent otitis media with effusion (POME) is found in 50% of young children after 10 days of antimicrobial therapy for acute otitis media. Pathogenic bacteria are present in at least 25% of such effusions. We studied the effect of a 2-week course of trimethoprim-sulfamethoxazole (TMP-SMX) administered to 33 children who had POME and compared the results obtained to those of a similar group of children with POME who did not receive drug therapy. This study was designed to answer two questions: (1) Would TMP-SMX promote the resolution of POME? (2) Would TMP-SMX prevent an attack of acute otitis media (AOM) superimposed on POME? The diagnosis of POME was validated by obtaining a type B tympanogram, and AOM was diagnosed according to strict criteria. Each child was randomly assigned either to a treatment group that received a 14-day course of TMP-SMX or to a control group that received no medication. TMP-SMX failed to promote resolution of POME but did prevent recurrent AOM. During the second 2-week (follow-up) phase of the study, when no antimicrobial was given to either subject group, the incidence of AOM was similar in both groups.

Child, Preschool↗