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Biomedical subjects

M Bobadilla

Publications and source records attributed to M Bobadilla.

28 records · Page 2Linked to original sources
PubMed1989

Epidemic of Serratia marcescens bacteremia and meningitis in a neonatal unit in Mexico City.

A case-control study was conducted on an epidemic of bacteremia and meningitis caused by Serratia marcescens in the neonatal intensive care unit and special care nursery of a general hospital in Mexico City, Mexico. A 19.9% incidence of bacteremia and meningitis was recorded in contrast to 1.4% and 3.7% during preepidemic and post-epidemic periods; a 69% mortality rate was observed. Peripheral IV catheters and the use of mixed IV fluids prepared in the wards were the major risk factors (P less than 0.001). Rectal and nasopharyngeal cultures were positive in 68% of asymptomatic neonates and hand cultures were positive in 16.7% of personnel. Strains were resistant to all aminoglycosides and broad-spectrum penicillins, and belonged to the A5/8 biogroup. Containment of this outbreak was difficult because of failure to identify colonized infants early in the epidemic and because of persistent carriage of S marcescens by personnel. Comparisons between this hospital and tertiary care centers in Mexico suggest that in developing countries nosocomial infections could be of greater magnitude in secondary than in tertiary level centers.

Cross Infection↗
PubMed1989

Improved method for bacteriological diagnosis of spontaneous bacterial peritonitis.

The definitive diagnosis of spontaneous bacterial peritonitis is made by a positive ascitic fluid culture. Causative organisms cannot be isolated in up to 65% of patients with well-defined spontaneous bacterial peritonitis, probably due to inadequate ascites culture techniques. We prospectively compared two ascites culture methods: conventional (on chocolate agar and thioglycolate broth) and modified (inoculation of 10 ml of ascites in a tryptic soy broth blood culture bottle at the patient's bedside). In a 10-month period, 31 cirrhotic patients met our diagnostic criteria for spontaneous bacterial peritonitis; both culture methods were performed on their ascitic fluid. The conventional method grew bacteria in only 16 of the 31 episodes (52%), whereas the modified method grew bacteria in 25 (81%), a significantly higher sensitivity (P less than 0.05). The modified method also shortened significantly the time for detection of bacterial growth. We conclude that ascites inoculation into a blood culture bottle at the patient's bedside should be the routine method for ascites culture.

Ascitic Fluid↗
PubMed1986

Control of emergence of multi-resistant gram-negative bacilli by exclusive use of amikacin.

Results of a three-year prospective study of amikacin as the only aminoglycoside used at the Instituto Nacional de la Nutrición "Salvador Zubirán" are presented. During the initial three-month baseline period, resistance to amikacin, gentamicin, and tobramycin among 870 gram-negative bacterial isolates was 3.2 percent, 17.4 percent, and 11.2 percent, respectively. In this period, the overall consumption of aminoglycosides was 69 percent for gentamicin, 30.5 percent for amikacin, and 0.5 percent for tobramycin. In the following period of exclusive amikacin use, sensitivity patterns of 9,344 gram-negative strains isolated over three years were recorded. During this period, amikacin constituted 99.3 percent of all aminoglycosides used. The percentage of gentamicin-resistant gram-negative strains declined to 7.4 percent (p less than 0.0001), whereas the percentage of amikacin-resistant strains did not change significantly. Quarterly trend analysis of aminoglycoside-resistant strains also demonstrated a significant decrease in gentamicin resistance (p less than 0.005) and an overall steady state of amikacin resistance. It is concluded that the exclusive use of amikacin was not accompanied by a significant increase in amikacin resistance during a three-year period, and may even lead to a decrease in resistance to gentamicin and tobramycin among most gram-negative organisms.

Amikacin↗
PubMed1982

Hypertrophic osteoarthropathy in cyanotic congenital heart disease: its prevalence and relationship to bypass of the lung.

The frequency of hypertrophic osteoarthropathy in cyanotic congenital heart disease has previously been considered to be very low. Only a few isolated reports have described such an association. We studied 32 consecutive patients older than 6 years with various types of cyanotic congenital heart disease and examined each case for hypertrophic osteoarthropathy. We also assessed the role of the altered cardiopulmonary hemodynamics in the development of hypertrophic osteoarthropathy by means of cardiac catheterization. Our results showed that 31% of the patients had hypertrophic osteoarthropathy. When the hemodynamic parameters of the group of patients with hypertrophic osteoarthropathy were compared with those of the remaining patients, we found significant differences in the systemic blood flow (P less than or equal to 0.05), right-to-left shunt (P less than or equal to 0.05), and arterial oxygen unsaturation (P less than or equal to 0.005). Thus, we found a much higher prevalence of hypertrophic osteoarthropathy in patients with cyanotic congenital heart disease than has previously been recognized. The development of hypertrophic osteoarthropathy is related to the degree of bypass of the lung. This is consistent with the concept that hypertrophic osteoarthropathy results from mediators in the systemic venous circulation that escape inactivation in the pulmonary capillary bed.

Adolescent↗
PubMedDate not supplied

Flow cytometric evaluation of the effects of doxorubicin on rat spermatogenesis.

Histopathologic examination of testicular tissue allows testicular impairment to be investigated. As an alternative to histopathology, flow cytometry (FCM) using a triple staining technique that combines DNA-ploidy with mitochondria stainability and vimentin immunostaining has also been utilized to evaluate testicular damage. In this article we evaluate the effects on spermatogenesis after acute exposure of rats to doxorubicin. Testicular cell suspensions of treated and control animals were analyzed by FCM. This allows several cell types to be identified and quantified, giving a control pattern. Deviations from this control pattern are considered as an indication of testicular damage. Doxorubicin produced a depletion of spermatogonia as early as 3 d after treatment. This effect could be followed through the temporal evolution of spermatogenesis. Comparable results were obtained by histopathology. The presented results show that FCM is a suitable and sensitive method for the detection of testicular damage. The advantages of FCM over other techniques include its rapidity and objectivity.

Animals↗
PubMedDate not supplied

New and traditional approaches for the assessment of testicular toxicity.

In this study, the suitability of several methods for the assessment of testicular damage, including histopathology, flow cytometry (FCM), testicular sperm head counts, and secretion of androgen binding protein (ABP), has been evaluated. Testicular toxicity after acute exposure of adult rats to different doses of the known toxicant 1,3-dinitrobenzene (DNB) was analyzed. The effects showed dose dependence, in spite of the large variability within each dose group. Histopathology and FCM showed germ cell depletion, particularly of round spermatids; testicular sperm head counts were reduced and ABP production was increased. All evaluated methods showed similar sensitivities. The increased testicular ABP levels support the theory that the Sertoli cell is the likely target of DNB induced testicular toxicity, producing subsequent germ cell depletion. The presented results show the suitability of FCM for the analysis of testicular damage and also support the usefulness of including a metabolic marker for Sertoli cell function.

Androgen-Binding Protein↗
PubMedDate not supplied

Recombinant cDNA encapsulation in small liposomes with hepatocyte access ability.

Liposomal encapsulation efficiency of a recombinant cDNA was studied by several procedures. We observed that supernatant fraction of ultracentrifuged liposomes prepared by extrusion through polycarbonate filters of 400 nm pore size yielded a very homogeneous suspension of small (50 nm diameter) unilamellar liposomes with highest DNA/lipid ratio and great ability to access to hepatocytes.

Animals↗