Search PubMed⌕ Search

Biomedical subjects

M I Marks

Publications and source records attributed to M I Marks.

At least 163 records · Page 9Linked to original sources
PubMed1975

Pharmacokinetics and efficacy of trimethoprim-sulfamethoxazole in the treatment of gastroenteritis in children.

In vitro studies indicates that the constitutents of the drug combination co-trimoxazole are synergistic against Salmonella and effective against shigella isolated from children ill with gastroenteritis. The drug is well absorbed in children with gastroenteritis due to a variety of causes and is distributed, excreted and metabolized in a manner similar to that seen in normal adult volunteers. The drug is tolerated well by children with gastroenteritis even in very high dosages. Despite its in vitro and pharmacokinetic advantages, co-trimoxazole was not any more efficient than any other durg or no therapy in the treatment of salmonella gastroenteritis; it seems to have a role, however, in the treatment of typhoid fever and may be life-saving in patients infected with ampicillin- and chloramphenical-resistant strains. It is also effective in the treatment of shigella gastroenteritis and is recommended where ampicillin-resistant strains are encountered. Its potential usefulenss for the treatment of other bacterial causes of gastroenteritis in children must be evaluated by further controlled therapeutic trials.

Administration, Oral↗
PubMed1975

In vitro activity of clindamycin and other antimicrobials against gram-positive bacteria and Hemophilus influenzae.

SUMMARY: Seven antimicrobials--clindamycin, penicillin, ampicillin, cloxacillin, erythromycin, lincomycin and cephalexin--were found to have a high degree of activity in vitro against 256 isolates of gram-positive bacteria and Hemophilus influenzae. Clindamycin was clearly superior against staphylococci and 3.12 mug/ml or less of clindamycin inhibited all 35 isolates of H. influenzae. Synergism was not demonstrated when clindamycin was tested in combination with sulfisoxazole or sulfamethoxazole by either the agar dilution or 24-hour growth curve method. This was true for penicillin as well, and the effect was independent of sulfonamide sensitivity. The erythromycin-sulfonamide combination was synergistic against 6 of 10 strains studied by the growth curve method; this effect was not demonstrable by the agar dilution method.

Ampicillin↗
PubMed1975

Susceptibilities of bacteria to different antibiotic regimens. Study in two nursery populations.

Hospital nursery A has used chloramphenicol and nursery B has used the combination of penicillin G sodium and kanamycin sulfate routinely in the treatment of neonatal sepsis and other bacterial infections. A hypothesis was formulated that these different antibiotic pressures would select out a substantial number of populations of resistant bacteria in each of the two nurseries. This was tested by periodic sampling of the skin, mouth, and rectal flora of babies and the permanent personnel in these nurseries. These bacteria were studied for susceptibility to a number of antibiotics. The population of resistant strains selected out was correlated with the antibiotics used in each nursery. There is a need for continuing surveillance of hospital nursery strains of bacteria for in vitro susceptibilities to commonly prescribed antimicrobials.

Aminoglycosides↗
PubMed1975

In vitro antibacterial activity of amikacin, a new aminoglycoside, against clinical bacterial isolates from children.

Four hundred and fifty-eight clinical bacterial isolates from a children's hospital were examined for antibiotic susceptibility to amikacin (BB-KS) in comparison with a number of other antibiotics by the disk diffusion and agar dilution methods. The wide spectrum of activity of amikacin against Gram-negative bacteria was confirmed; it included E. coli, Proteus species, Enterobacter species, and Pseudomonas aeruginosa. Staphylococci were highly sensitive, but other Gram-positive bacteria tested were resistant. A disk zone diameter of 10 mm effectively separated resistant form sensitive bacteria in a standard disk diffusion test.

Amikacin↗
PubMed1975

Yeast colonization in hospitalized and nonhospitalized children.

Data have been accumulated to determine the prevalence of yeast colonization of the skin and digestive tract of hospitalized and nonhospitalized infants and children. There was no difference in the prevalence between hospitalized patients at the time of admission and nonhospitalized children. However, there was a positive correlation of the duration of hospitalization and the prevalence of yeast colonization. There were no correlations of hospitalization with site of colonization, age of the patient, or type of yeast isolated.

Adolescent↗
PubMed1975

Evaluation of four antiviral agents in the treatment of herpes simplex encephalitis in a rat model.

Three hundred four animals were used for the systematic evaluation of the in vivo efficacy of 5-iodo-2'-deoxyuridine (IUDR), cytosire arabinoside, 9-beta-arabinofuranosyladenine, and isoprinosine in the therapy of herpes simplex encephalitis in an adult rat model. Type 1 herpes simplex virus was inoculated intracerabrally, and drug was administered by the intraperitoneal route. All experiments included tests for toxicity and viral controls, Eight sets of experiments were used for evaluation of ttherapy with IUDR; the inoculum ranged from 64 to 2,000 TCID50, dose of drug from 0.1 mg/g to 1.0 mg/g per day, and duration of therapy from one to five days. There was no significant improvement in the number of animals surviving or in the survival time when the viral controls were compared with mice in treated groups. A slight trend toward increased survival time and decreased titer of virus in the brains of animals treated with IUDR was noted in the group that received the largest dose. Three or four sets of experiments were used to evaluate each of the other three antiviral drugs. Results were similar to those reported for IUDR. These results indicate a need for further studies, including investigations of the pharmacology and toxicity of these antiviral agents, to establish more clearly the dosages of drug that are therapeutic, those that are toxic, and ratios of these dosages.

Acetanilides↗
PubMed1975

An outbreak of severe pneumonia due to respiratory syncytial virus in isolated Arctic populations.

A rapidly developing outbreak of pneumonia in young infants was documented in two isolated Artic populations in May 1972. These were studied virologically, serologically and clinically. In addition to the two stricken communities, one apparently unaffected with serious clinical illness and a fourth, in which are located the major hospital and airport in the eastern Arctic, were also studied. One hundred and twenty-four patients were studied serologically and 81 respiratory and other specimens were obtained for virus isolation from 40 of these patients. Clinical records were kept of the outbreak in each area and a detailed questionnaire was filled out for 140 children and their families. Respiratory syncytial irus (RSV) was cultured from eight ill children. Electron microscopy provided the first evidence of RSV infection. A seroconversion rate of approximately 50% was seen in both affected communities as well as in the clinically unaffected one. The epidemic in the first two communities was characterized by severe pneumonia and frequent hospitalization but no cases of bronchiolitis were seen. No evidence for other causes of this outbreak could be obtained by testing for antibodies to influenza A and B, parainfluenza 1, 2 and 3, adenovirus and herpes simplex viruses. Unusual features of this epidemic of RSV infection include the high attack rate, severe morbidity, illness manifest almost exclusively as pneumonia rather than bronchiolitis and the difference between the expression of disease in different communities. Historical data and clinical observations were inadequate to explain these unusual features.

Adult↗
PubMed1975

Influences of media and inocula on the in vitro susceptibility of Haemophilus influenzae to co-trimoxazole, ampicillin, penicillin, and chloramphenicol.

The effects of inocula and media on the activities of ampicillin, penicillin, chloramphenicol and co-trimoxazole against Haemophilus influenzae were examined in vitro. Two inocula and four media were tested by the disk diffusion, broth dilution, and agar dilution methods. Chloramphenicol activity versus H. influenzae was least affected by changes in inocula and media, whereas co-trimoxazole was most susceptible to these effects. Filde's and Levinthal's agar dilution tests were most satisfactory for ampicillin. Penicillin was less active on Levinthal's than on Filde's agar. Both ampicillin and penicillin were less active when tested against the higher inoculum. Co-trimoxazole was most active (<1% H. influenzae was resistant) when tested at an inoculum of 10(6) colony-forming units/ml on diagnostic susceptibility test agar with 5% lysed horse blood added. The majority of H. influenzae appeared resistant to co-trimoxazole with increases in the test inocula and/or when tested on brain heart infusion with Filde's, Levinthal's or "low-thymidine" Mueller-Hinton medium.

Ampicillin↗
PubMed1975

Passive immunization in experimental Herpesvirus hominis infection of newborn mice.

Infection of newborn mice with Herpesvirus hominis type 2(HVH-2) was used as an experimental model of disseminated HVH infection in newborn humans. Mice were challenged with 103 plaque-forming units of HVH-2 intranasally and were given 0.2 ml of rabbit serum intraperitoneally. Passive immunizations with rabbit anti-HVH-2 serum resulted in a significant decrease in mortality and prolongation of survival time. This effect correlated with the neutralizing antibody titer of the serum against HVH-2 and was more pronounced when immune serum was administered 1 h after infection as compared with 24 h. These results suggest that administration of high-titer anti-HVH-2 immunoglobulins shortly after delivery could afford significant protection to the newborn of a mother with genital HVH-2 infection.

Animals↗
PubMed1975

Antibacterial activity of tobramycin against gram-negative bacteria and the combination of ampicillin/tobramycin against E. coli.

The antibacterial activity of tobramycin, gentamicin, erythromycin, cloxacillin, kanamycin, cephalexin, penicillin, carbenicillin and polymyxin were compared against 303 clinical bacterial isolates from a pediatric hospital patient population. Standard disk diffusion and agar-dilution methods were employed. Significant activity was demonstrated for tobramycin against pseudomonas, Klebsiella, Escherichia coli and both Staphylococcus aureus and albus; Tobramycin was significantly more active against Pseudomonas than gentamicin or the other antibiotics testedmcomparable activity to gentamicin was present for the other types of bacteria; Cross-resistance was not encountered between tobramycin and gentamicin. 30 isolates of E. coli were tested against the combination of tobramycin and ampicillin by the growth-curve method. Synergism was demonstrated in 4 isolates, antagonism in 1 and an additive effect in 25. A bactericidal effect was present at 24h against 17 isolates with tobramycin alone and against 25 isolates when combined with ampicillin. These results provide in vitro rationale for the consideration of tobramycin for clinical use in patients with Psuedomonas infections for the combination of ampicillin and tobramycin for the treatment of selected E.coli infections.

Ampicillin↗
PubMed1975

The timing of tuberculin tests in relation to immunization with live viral vaccines.

The validity of the recommendation that routine screening for tuberculosis precede the administration of live viral vaccines was tested in a field study. One hundred and ten children already known to be tuberculin-positive, mostly on the basis of prior vaccination with BCG, were immunized with live viral vaccine and retested with tuberculin at the same time. Reversion to a negative tine test occurred in 3% of children given measles, mumps, or rubella vaccine, and 3.6% of controls who received no vaccine but had the tuberculin test repeated at the same interval. Very few Mantoux reactions (two of 68) reverted to negative in children given one of the three vaccines, singly or in combination; some became smaller, but there was no significant difference in the changes in the size of the Mantoux reaction between the vaccinated group and the control group, with the exception of an unexplained increase in the size of the reaction in many of those who received rubella vaccine. Screening for tuberculosis by tine or Mantoux test is not invalidated by simultaneous administration of vaccines against measles, mumps, or rubella, given singly or in combination, as part of preventive care programs.

Adolescent↗
PubMed1975

Coxsackieviruses in human disease.

The outstanding feature of this group of viruses is the wide spectrum of disease it produces in man. Type B viruses have been associated with gastroenteritis, pleurodynia, pharyngitis, meningoencephalitis, aseptic meningitis, pericarditis, myocarditis and respiratory infections. Type A viruses are associated with herpangina, hand, foot and mouth disease, conjunctivitis, meningoencephalitis and respiratory infections. The diagnostic virology laboratory is developing rapid methods of identification.

Adult↗
PubMed1974

Clinical spectrum and carrier state of nontyphoidal salmonella infections in infants and children.

A study was done of 117 children with nontyphoidal salmonellosis from the clinic and inpatient populations of The Montreal Children's Hospital. Uncomplicated gastroenteritis was the most common clinical presentation and the mean duration of illness was 8.7 days. Eleven (24%) of 45 patients tested had bacteremia; retrospective analysis of these patients did not reveal major differences in clinical presentation, laboratory findings, underlying disease or complications when compared with the patients from whom blood cultures were not taken. There were no complications in any of the patients and no deaths. Prolonged stool carriage beyond eight weeks was not a problem except in infants under the age of 3 months, of whom 27% were carriers eight weeks after the onset of illness. Antibiotic therapy was not effective in treating the acute illness and seemed to prolong carriage in young infants.

Adolescent↗
PubMed1974

Variables influencing the in vitro susceptibilities of herpes simplex viruses to antiviral drugs.

Some of the variables in a microtiter tissue culture method for estimating antiviral susceptibility of herpes simplex viruses (HSV) were studied. Six antiviral drugs (5-iodo-2'-deoxyuridine, cytosine arabinoside, 9-beta-arabinofuranosyladenine, isoprinosine, virazole, and 2-deoxy-d-glucose) and three tissue culture cell lines (primary rabbit kidney, WI-38, and rat brain) were studied. Four different inocula (10, 100, 1,000, and 2,000 mean tissue culture doses) and nine isolates of HSV were tested. Minimal inhibitory concentration was defined as a complete inhibition of cytopathogenic effect in tissue culture cells after 72 h of incubation. There was a direct relationship between the viral inocula and the minimal inhibitory concentration. There were also differences between the three tissue culture cell lines and among the different strains of herpesvirus. This was not type specific, and the strain differences were not consistent in different tissue culture lines. Cytosine arabinoside appeared to be the most active drug in vitro, with 5-iodo-2'-deoxyuridine intermediate in activity between cytosine arabinoside and 9-beta-arabinofuranosyladenine; no significant cytotoxicity was encountered with these drugs. Isoprinosine, virazole, and 2-deoxy-d-glucose were not effective against any of the nine strains of HSV tested in this in vitro system; a comparison with previous studies indicates that their activity may be cell dependent. These results emphasize the importance of careful evaluation of in vitro test methods for the susceptibility testing of antiviral agents against HSV. Marked variability between strains and in vitro test systems caution against the application of these methods to in vivo situations until further studies are carried out.

Antiviral Agents↗