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Biomedical subjects

C Alvarado

Publications and source records attributed to C Alvarado.

At least 37 records · Page 2Linked to original sources
PubMed1990

Transfers of frozen-thawed human embryos in cycles stimulated by HMG.

A total of 130 transfers of frozen-thawed (F-T) human embryos was carried out after moderate ovarian stimulation with human menopausal gonadotrophin (HMG). Embryos were replaced 3 days after the spontaneous luteinizing hormone (LH) surge or 4 days if ovulation was induced by human chorionic gonadotrophin (HCG). Embryos were thawed a few hours prior to transfer. One-hundred-and-twenty-three transfers were effective and 23 pregnancies were achieved. The rate of ongoing pregnancies per transfer was 17.9% (22/123). The survival rate of embryos originating from cycles stimulated by a combination of an LHRH analogue and HMG in a long protocol (LA-HMG protocol) was significantly lower when compared with the rate of embryos retrieved from clomiphene citrate-HMG (CC-HMG protocol) stimulated cycles (52 versus 67%, P less than 0.05). When fresh embryos originated from cycles stimulated with an LHRH analogue and HMG in a short protocol (SA-HMG protocol), the survival rate was not affected (59 versus 67%, NS). Although the difference was not significant, the ongoing pregnancy rate per transfer according to the three protocols from which the embryos originated seemed to be better with the SA-HMG protocol: 16% with the CC-HMG protocol, 14.5% with the LA-HMG protocol versus 27.6% with the SA-HMG protocol. The success rate was independent of the number of F-T transferred embryos if at least one embryo with 100% intact blastomeres was replaced.

Cryopreservation↗
PubMed1987

Natural killer cells in children with acute leukemia. The effect of interleukin-2.

The purpose of this study was to determine (1) the number and activity of natural killer (NK) cells in children with acute leukemia at different stages of their disease; and (2) the effect of interleukin-2 (IL-2) in enhancing NK activity of these patients' cells. The mean percentage of Leu 11+ NK cells in patients at diagnosis (5% of peripheral blood (PB) mononuclear cells) was significantly lower than for patients on maintenance (23%), post-treatment (21%) and for normal children (20%). The mean PB NK cell cytotoxicity for patients at diagnosis (16% lysis versus K562) and during maintenance (20%) was significantly lower than for post-treatment (41%) and normal controls (40%). After NK cells were incubated for 5 days with IL-2, NK cells from 82% (36/44) of patients showed enhanced cytotoxicity toward K562 and several acute leukemia cell lines as well as toward autologous leukemic cells. Cytotoxicity toward autologous cells was very low (0% to 5%, 16 hour assay) before IL-2 stimulation, and significantly increased (23% to 69%) after stimulation, suggesting that IL-2 may be a useful agent for enhancing the antileukemic immune response.

Acute Disease↗
PubMed1986

Sequential testicular biopsies in childhood acute lymphocytic leukemia.

Between August 1978 and November 1981, 33 boys with acute lymphocytic leukemia (ALL) (26 non-T, 7 T-cell) younger than 16 years underwent bilateral wedge testicular biopsies at the time of initial diagnosis. Seven (4 non-T, 3 T-cell) demonstrated focal leukemic infiltrates. Rebiopsy after successful induction therapy without testicular irradiation showed eradication of leukemic infiltrates in five, persistent focal infiltrates in one, and a diffuse infiltrate in one. The two patients who had persistent leukemic involvement had a T-cell phenotype, and in one of them overt testicular disease developed 2 years later. All 33 patients were followed prospectively for a minimum of 3 years. Fifteen (14 non-T, 1 T-cell) remained in remission for 3 years and underwent another testicular biopsy before the cessation of therapy. Two patients, both non-T and both of whom were free of testicular involvement at diagnosis, showed testicular infiltrates at that time. Of the seven boys with positive specimens at diagnosis, only two remained disease-free for 3 years and showed no testicular involvement upon the completion of chemotherapy. In this study, microscopic testicular involvement by lymphoblasts occurred in 21% of newly diagnosed boys with ALL; this occurred only if the leukocyte count exceeded 25,000/microliter. These patients in general had a poor prognosis, probably reflecting the overall heavy tumor burden. However, it was not possible to predict accurately those patients who would have leukemic testicular infiltrates at the cessation of chemotherapy by performing biopsy of the testes at the time of initial diagnosis or after induction therapy.

Adolescent↗
PubMed1986

Double-bagging of items from isolation rooms is unnecessary as an infection control measure: a comparative study of surface contamination with single- and double-bagging.

In many hospitals, waste materials and used linens from the rooms of patients in isolation or the clinical laboratories are routinely double-bagged to reduce contamination of the external surface of the bag that could be transmitted to hospital personnel subsequently handling them. No studies have prospectively examined the value, if any, of double-bagging. We randomly assigned waste and linens from the rooms of 42 patients in contact isolation to be transported in single bags or double bags. Shortly after a single (or double) bag had been set outside the patient's room, the surface was cultured quantitatively in two locations near the knot; over 2 months, 209 bags were cultured. Surface contamination by Staphylococcus aureus (3% to 5%), enteric gram-negative bacilli (6% to 7%), or either (9% to 12%) was infrequent and comparable in both groups; moreover, quantitative levels of contamination in the two groups were almost identical (mean, 27 and 29 colony forming units [cfu] per bag). These data suggest that there is no advantage, as regards asepsis, to double-bagging potentially contaminated items from isolation rooms or clinical laboratories as compared with using a single bag. The use of a single-bag system with a heavy-duty bag, as compared with double-bagging, saved our hospital $9,400 in 1985.

Bedding and Linens↗
PubMed1983

Malignant histiocytosis after lymphoblastic lymphoma.

Malignant histiocytosis developed in a 19-year-old boy 3 1/2 years after the initial diagnosis of lymphoblastic lymphoma of T-cell origin. The experience with this young adult suggests that a close surveillance of the survivors of lymphoma is mandatory, and a prompt biopsy of enlarged lymph nodes in patients treated for lymphoma should be a routine procedure.

Adolescent↗
PubMed1982

Two new acute lymphoblastic leukemia cell lines with early B-cell phenotypes.

Two leukemic cell lines (697 and 207) were established from bone marrow cells obtained from children with ALL in relapse. These cell lines were positive for the common-ALL antigen (CALLA), the HLA-DR (i.e., Ia-like) antigen, and for cytoplasmic and surface IgM heavy chains. The lines were negative for other immunoglobulin heavy chains and light chains. The lines had elevated levels of terminal deoxynucleotidyl transferase enzyme and expressed surface antigens found on normal myeloid-macrophage cells (MMA) and on natural killer cells (HNK-1). A minority of cells in line 207 expressed the T-1, T-6, and Leu-1 antigens as detected by monoclonal antibodies. Line 697 was positive for Epstein-Barr virus (EBV), while line 207 did not possess EBV. Line 697 carried a marker chromosome (identified as a translocation between chromosomes 7 and 19), which was also patient's fresh leukemic cells. The leukemic origin of the cell lines was further indicated by their morphological, cytochemical, and immunologic similarity to the patients' leukemic cells. Phenotypically, both cell lines appear to be arrested in a transitional stage of development between pre-B and B cells and express surface antigens usually found on normal and fresh leukemic cells of non-B-cell lineages.

Antigens, Neoplasm↗
PubMedDate not supplied

Improvement of leukocyte functions in young prematurely aging mice after a 5-week ingestion of a diet supplemented with biscuits enriched in antioxidants.

In our previous studies, diet supplementation with therapeutic thiolic antioxidants improved the function of peritoneal leukocytes from mice, especially in adult prematurely aging mice (PAM). In the present work, we have studied the effects of ingestion during 5 weeks of a diet supplemented with 20% (wt/wt) of biscuits enriched with antioxidants (vitamin C, vitamin E, beta-carotene, zinc, and selenium) on several immune functions of peritoneal leukocytes from young PAM. The results show that, in macrophages, chemotaxis and phagocytosis as well as the intracellular free radical levels, which are depressed in PAM in comparison with the control nonprematurely aging mice (NPAM), increase after supplementation, especially in the PAM. An increase also occurs in lymphocyte chemotaxis, proliferative response to the mitogen concanavalin A, and interleukin-2 release, as well as in natural killer cell activity. However, the release of tumor necrosis factor-alpha, which increases with aging, decreases after 5 weeks of supplementation. As a well preserved function of the immune system is an excellent marker of health and longevity, the improvement of leukocyte functions after ingestion of the present diet suggests that this antioxidant supplementation may be useful for the preservation of health and functional longevity in aging populations.

Aging↗