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Biomedical subjects

M Gamboa

Publications and source records attributed to M Gamboa.

8 recordsLinked to original sources
PubMed2001

Norepinephrine modulates myelopoiesis after experimental thermal injury with sepsis.

OBJECTIVE: To determine whether thermal injury and sepsis cause an increase in bone marrow norepinephrine release and whether such a release influences bone marrow monocytopoiesis. SUMMARY BACKGROUND DATA: The authors previously demonstrated enhanced bone marrow monocytopoiesis after burn with sepsis. They also showed that physiologic stress and bacterial challenge without injury could lead to a dynamic release of norepinephrine from the bone marrow compartment. In this study, they sought to determine the potential cause-and-effect relationship of bone marrow norepinephrine release on increased monocytopoiesis after burn sepsis. METHODS: Norepinephrine release from bone marrow was determined by traditional pulse-chase methods. Tissue and bone marrow norepinephrine content was ablated by chemical sympathectomy with 6-hydroxydopamine treatment. Clonogenic potential in response to colony-stimulating factors was determined in total nucleated bone marrow cells. Dual color flow cytometry was used to document the distribution pattern of monocyte progenitors. RESULTS: Burn sepsis induced increased norepinephrine release in bone marrow, spleen, and heart. Colony-forming assays demonstrated an increase in responsive colonies, which was significantly attenuated when norepinephrine content was reduced in animals before burn sepsis. Flow cytometric analysis of early and late monocyte progenitors showed a significantly altered distribution profile of monocyte progenitors in norepinephrine-depleted mice compared with norepinephrine-intact mice. Abrogation of bone marrow norepinephrine content resulted in a 62% survival rate in burn septic mice compared with no survivors in norepinephrine-intact mice. CONCLUSIONS: These data suggest that enhanced bone marrow norepinephrine release after burn sepsis may play a role in bone marrow monocytopoiesis, thus contributing to the sustenance of inflammation.

Animals↗
PubMed1998

Ultrastructural study of the skin after facial chemical peels and the effect of moisturization on wound healing.

Ultrastructural changes occurring in the skin at early times after chemical peels as well as effects on the wound healing with moisturization after these peels have been examined. This study evaluated the changes seen in the skin 3 days and 5 days after 35% trichloroacetic acid peels, and the effect of moisturization on this healing was evaluated. Biopsies at 3 days showed an outermost layer of necrotic stratum corneum and stratum granulosum and an underlying layer of new stratum corneum. There were increased cytoplasmic vacuoles in the keratinocytes of the stratum spinosum, stratum granulosum, and stratum basale layers. There was extensive intercellular spacing between the basal keratinocytes. At 5 days the necrotic layer of stratum corneum and stratum granulosum was gone. The lower epidermis at 5 days showed less intercellular spacing, and there was less vacuolization within keratinocytes. In seven of eight patients treated with moisturization after the peel (p = 0.0325), the ultrastructural changes at 5 days were consistent with a more advanced state of healing compared with those that were treated dry. Ultrastructural morphology at this time showed less intercellular spacing and fewer cytoplasmic vacuoles, indicative of an advanced state of wound repair. These moisturized skin specimens had returned to an almost normal state of structure compared with the skin that had been treated dry.

Biopsy↗
PubMed1998

[Serum hepatitis B markers in blood donors in Venezuela. What do they mean?].

PURPOSE: The prevalence of serum BH markers is high in our country. In order to assess the factors of impact in this fact a group of blood donors with positive BH markers attending our Service between 1-1-95 and 12-31-96 was evaluated, although the endemic character of the disease may be an obstacle for its recognition. The residual risk of HBV transmission by seronegative transfusions was also evaluated. MATERIAL AND METHODS: The evaluation of donors was performed by surveying identification data, type and frequency of donations and risk factors. The following reagents were used to carry out the bests: Biotest Elisa HbsAgand Heprofile anti HBc, ADI Diagnostics (1995), and Abbott Auzyme Monoclonal and Abbott Corzyme Diagnostic kit. Positive donors were re-evaluated to determine any progression of the disease and they were classified into false positive (FP), chronic carriers (CC), acute hepatitis (AH), naturally immunized (NI), or without evidence of immunity (WI). The residual transfusional risk was calculated by multiplying the adjusted prevalence of HbsAg positive donors by the window period expressed in fractions of a year. RESULTS: Out of 53,338 donations, 5.91% were discarded due to the presence of HBV, 7.5% of them showing significant association with other markers: HCV, Chagas' disease and syphilis. Of all donors 223 (7.54%) returned for re-evaluation, and only 139 (62.33% of them) could be fully evaluated as follows: FP 10.09%, AH 5.76%, CC 7.19%, NI 68.35%, WI 7.91%. Their mean age was 35.73 +/- 9.95 years, and there were 112 males and 12 females. The donations were patient-related in 93.5% of cases, voluntary in 3.22% and coming from mobile units in 3.22% of instances (p = 0.067). Fifth per cent donated for the first time, and the other 50% had donated previously although not in a consecutive way (p = 0.96): 46% were ignorant of their post-donation findings, 37.09% were seemingly negative and 16.12% had positive tests. Of these last, the reasons for donation included defective questioning and information (50%), results not verified (20%) and family/hospital pressure (30%). Homo/bisexuality and drug abuase (not intravenous) were found significant when associated to each other or to promiscuity. Promiscuity attained significant risk value, especially when previous venereal disease or close contact with BH patients were presented (p = 0.0015, p = 0.155, and p = 0.0036, respectively). The residual risk of transmitting HBV by seronegative transfusions was found to be: 1:437. CONCLUSIONS: 1. No risk factors were detected in a half of the cases. 2. The other half, comprising the known seropositive subjects and the promiscuous, homo/bisexual donors and those having close contact with HBV patients, can be discarded predonation. 3. Drug abuse (not intravenous), frequently associated with other risk factors, should discard a donor. 4. History of veneral disease should be considered a risk factor due to its common association to HBV. 5. The residual risk of acquiring HBV post-transfusion is still high. RECOMMENDATIONS: 1. To improve the information provided to donors regarding the risk factors. 2. The interrogation should be simple, direct and deep. 3. To insist in the importance of the donor returning for his/her credentials in the blood bank and to know about any altered results, and to seek medical advice when appropriate. 4. To change related donation into a voluntary and consecutive pattern.

Adult↗
PubMed1990

Treatment of breast cancer by radical surgery: a personal experience of 653 patients with minimal follow-up of 10 years.

From June 1952 through December 1976, 695 radical operations were performed on 653 women suffering from invasive cancer of the breast. All operations were performed by a single surgeon (E.C.); the same principles in the selection of the patient techniques of surgery and overall treatment were practiced. Postoperative radiation therapy was used only in the beginning of the study, and 56 (15.9%) of the group with axillary metastases received such therapy. No patient with negative axillary lymph node received radiation therapy. No postoperative adjuvant chemotherapy or immunotherapy was administered. Complete follow-up data were obtained in 94.7% of all patients. In accord with the UICC clinical classification, 96 were classified as stage I (14.7%), 445 as stage II (68.1%), and 111 as stage III (17.%); 1 (0.1%) was not classified. From the 653 patients, 651 (two postoperative deaths) were observed for an average of 141.9 months. The longest period of follow-up evaluation for any patient was more than 35 years and the minimum, 10 years. Survival was calculated for the entire study group and for patients classified by nodal status and stage of disease. The 10-year overall survival rate for 651 patients is 60.4%; for those with positive nodes 46.4%, and for those with negative nodes, 76.7%. The overall survival, according to clinical stage, was as follows: the 5-year survival for patients in stage I was 89.5%, and the 10-year survival was 83.1%. In the stage II group, the 5-year survival was 76.1% and the 10-year survival, 58.5%. The patients in stage III had only a 62.1% 5-year survival and a 47.7% 10-year survival.

Adult↗
PubMed1988

Two years of cyclophosphamide and 5-fluorouracil as adjuvant chemotherapy for stage II and III breast carcinoma.

The results after 6 years of a prospective clinical trial of adjuvant chemotherapy with a regimen of two drugs--cyclophosphamide and 5-fluorouracil (CF)-- for 2 years in 97 women with stage II or III breast cancer are reported. Eligible patients were free from distant metastases. All patients began adjuvant therapy within 4 weeks of surgery; therapy consisted of radical, modified, or extended radical mastectomy. No postoperative radiotherapy was given. The results are compared with a historical control group from previous consecutive patients treated by surgery alone. Patients were stratified by age (younger than 50 or older than or equal to 50) and nodal status (one to three positive axillary nodes vs. four or more positive nodes). The estimated 6-year survival was 60% for CF patients vs. 31% for control patients (P = 0.001). The estimated 6-year disease-free survival was 53.6 and 30.3% for CF and control, respectively (P = 0.007). There was a trend toward longer disease-free survival (DFS) and survival (S) in patients treated with CF, but this was not significant in all the subgroups. Disease-free survival was statistically significant in the subgroup of women greater than or equal to 50 years old with one to three positive nodes (P = 0.038); survival in the patients less than or equal to 49 years old with four or more positive nodes (P = 0.0036); and in patients greater than or equal to 50 years old with one to three lymph nodes involvement (P = 0.038).

Adult↗
PubMed1987

Epidemiological aspects of Clostridium difficile in a pediatric hospital and its role in diarrheal disease.

The influence of antibiotics on the frequency of colonization by Clostridium difficile and the presence of its cytotoxin in infants and older children was examined to determine its role in diarrheal disease. Cytotoxin was more closely associated with cases of diarrhea, both in infants and in children than the microorganism, although not significantly. The isolates were typed by means of sensitivity to bacteriophages and bacteriocins and their cytotoxigenic potential was also determined. Less than 30% of the colonized patients had toxigenic strains. A study of strain variability over a four-year period in the same hospital showed that two bacteriophage-bacteriocin types and non-toxigenic strains predominated. The common presence of non-toxigenic strains could explain in part the lack of correlation between isolation of Clostridium difficile and diarrhea. Most of the non-toxigenic strains showed moderate resistance to tetracycline, a property which might explain their ability to persist for long periods in the hospital.

Adolescent↗