Biomedical subjects
C Moreno
Publications and source records attributed to C Moreno.
Abnormal pressure-natriuresis in hypertension: role of cytochrome P450 metabolites of arachidonic acid.
The pressure-natriuresis relationship is shifted to higher pressures in genetic and experimental models of hypertension; however, the factors responsible for altering kidney function remain to be determined. In spontaneously hypertensive (SHR) and Lyon hypertensive rats, the resetting of pressure-natriuresis results from increased preglomerular renal vascular tone, whereas sodium reabsorption is elevated in the thick ascending loop of Henle (TALH) of Dahl S rats. Recently, a new route for the renal metabolism of arachidonic acid (AA) has been described, and there is evidence that this pathway contributes to the resetting of renal function in hypertension. In the kidney, cytochrome P450 (CYP) enzymes metabolize AA primarily to 20-HETE and EETs. 20-HETE is a potent constrictor of renal arterioles that has an important role in autoregulation of renal blood flow and tubuloglomerular feedback. 20-HETE and EETS also inhibit sodium reabsorption in the proximal tubule and TALH. In the SHR, the renal production of 20-HETE is elevated and inhibitors of the formation of 20-HETE decrease arterial pressure. Blockade of 20-HETE formation also reduces blood pressure or improves renal function in deoxycorticosterone acetate (DOCA)-salt, angiotensin II--infused, and Lyon hypertensive rats. In contrast, 20-HETE formation is reduced in the TALH of Dahl S rats and this contributes to elevated sodium reabsorption. Induction of 20-HETE synthesis improves pressure-natriuresis and lowers blood pressure in Dahl S rats, whereas inhibitors of the synthesis of 20-HETE promote the development of hypertension in Lewis rats. These findings indicate that the renal production of CYP metabolites of AA is altered in genetic and experimental models of hypertension and that this system contributes to the resetting of pressure-natriuresis and the development of hypertension in some models.
Statistical power of QTL mapping methods applied to bacteria counts.
Most QTL mapping methods assume that phenotypes follow a normal distribution, but many phenotypes of interest are not normally distributed, e.g. bacteria counts (or colony-forming units, CFU). Such data are extremely skewed to the right and can present a high amount of zero values, which are ties from a statistical point of view. Our objective is therefore to assess the efficiency of four QTL mapping methods applied to bacteria counts: (1) least-squares (LS) analysis, (2) maximum-likelihood (ML) analysis, (3) non-parametric (NP) mapping and (4) nested ANOVA (AN). A transformation based on quantiles is used to mimic observed distributions of bacteria counts. Single positions (1 marker, 1 QTL) as well as chromosome scans (11 markers, 1 QTL) are simulated. When compared with the analysis of a normally distributed phenotype, the analysis of raw bacteria counts leads to a strong decrease in power for parametric methods, but no decrease is observed for NP. However, when a mathematical transformation (MT) is applied to bacteria counts prior to analysis, parametric methods have the same power as NP. Furthermore, parametric methods, when coupled with MT, outperform NP when bacteria counts have a very high proportion of zeros (70.8%). Our results show that the loss of power is mainly explained by the asymmetry of the phenotypic distribution, for parametric methods, and by the existence of ties, for the non-parametric method. Therefore, mapping of QTL for bacterial diseases, as well as for other diseases assessed by a counting process, should focus on the occurrence of ties in phenotypes before choosing the appropriate QTL mapping method.
Impaired response to interferon-gamma in activated macrophages due to tyrosine nitration of STAT1 by endogenous nitric oxide.
1. Inducible NO synthase (iNOS) expression and activity were measured in the mouse macrophage cell line J774 after exposure to bacterial lipopolysaccharide (LPS) with or without interferon-gamma (IFN-gamma). 2. Inhibition of NOS activity by concomitant N(G)-monomethyl-L-arginine (L-NMMA) treatment further increased iNOS protein levels, with a substantial increase in iNOS half-life. 3. Western blotting and ELISA demonstrated that several cell proteins were tyrosine-nitrated when iNOS activity was high. 4. Rapid IFN-gamma-induced phosphorylation of STAT1 was reduced by about 40% when cells were pretreated to induce iNOS, unless L-NMMA was present during the pretreatment period. 2D gel electrophoresis demonstrated the presence of nitrotyrosine in STAT1 after iNOS induction, and confirmed the reduction in phospho-STAT1 on subsequent stimulation with IFN-gamma for 15 min and its partial restoration when L-NMMA was present during the pretreatment period. 5. We did not detect tyrosine nitration of the upstream kinase JAK2 in LPS+IFN-gamma pretreated cells, but JAK2 activity was also impaired, and was partially restored by concomitant L-NMMA pretreatment. 6. We conclude that endogenous production of NO induces feedback inhibition of signalling pathways activated by IFN-gamma, at least in part by nitrating tyrosine residues in STAT1 which prevents phosphorylation.
Epithelioid blue naevus of the genital mucosa: report of four cases.
Epithelioid blue naevi are an unusual cytological variant of blue naevus that have been recently described mostly in patients with the Carney complex, although they may also occur in isolation. This variant of blue naevus is composed of melanin-laden polygonal epithelioid melanocytes situated within the dermis. The neoplastic cells show no maturation with progressive depth of dermal infiltration and, in contrast with the usual stromal changes in blue naevi, epithelioid blue naevi exhibit no dermal fibrosis. We describe four cases of epithelioid blue naevus located on the genital mucosa in four patients with no evidence of the Carney complex. Three male patients showed an epithelioid blue naevus on the mucosa of the glans penis and a female patient had a lesion of the right labium minoris. Histopathologically, the lesions consisted of entirely intradermal melanocytic naevi composed mostly of heavily pigmented epithelioid melanocytes involving the dermis of the genital mucosa. Immunohistochemically, in all cases, epithelioid melanocytes expressed immunoreactivity for S-100 protein, HMB-45, Melan-A and MiTF antibodies.
Cytochrome P450 metabolites of arachidonic acid: novel regulators of renal function.
Explore the source record for details and available documents.
Postirradiation pseudosclerodermatous panniculitis.
Pseudosclerodermatous panniculitis is an unusual variant of panniculitis that results as a complication of megavoltage radiotherapy. Four women developed this unusual entity on the anterior chest and abdominal skin after receiving megavoltage therapy for either breast carcinoma or painful bone metastases from breast carcinoma. Histopathologically, the epidermis and dermis of the involved area showed little or no evidence of radiodermatitis. The main findings were confined to the subcutaneous tissue and consisted of thickened, sclerotic septa composed of both thick and thin collagen bundles, and a lobular panniculitis characterized by lipophagic granulomas and scattered lymphocytes and plasma cells. Additionally, one of the cases showed markedly dilated vascular spaces with the appearance of lymphatics in the upper part of the dermis. Pseudosclerodermatous panniculitis after irradiation is an unusual cutaneous complication of megavoltage radiotherapy that should be distinguished from subcutaneous metastatic disease, cellulitis, or connective tissue diseases involving the subcutaneous fat. The differential diagnosis can be established on the basis of the characteristic histopathologic features of postirradiation pseudosclerodermatous panniculitis.
Animal type melanoma: a report of a case with balloon-cell change and sentinel lymph node metastasis.
Animal type melanoma is a rare histopathologic variant of melanoma characterized by sheets and nodules of heavily pigmented epithelioid melanocytes that involve the entire thickness of the dermis. This human neoplasm mimics melanocytic neoplasms seen in gray horses and laboratory animals; thus, is termed animal type melanoma. It is quite rare and, with only a few reported cases, its biological behavior is not well understood. We report an example of animal type melanoma on the back of a 27-year-old man. The lesion showed areas of melanoma in situ, which ruled out the possibility of metastatic melanoma. Features of regression were also seen at dermo-epidermal junction and papillary dermis. In some areas, neoplastic melanocytes exhibited a balloon-cell appearance; in others the neoplasm was composed of sheets and fascicles of heavily pigmented epithelioid melanocytes that permeated the entire dermis and extended into the dermal-subcutaneous interface, mimicking a cellular blue nevus. Epithelioid melanocytes in deeper areas showed abundant, heavily pigmented cytoplasm and pleomorphic nuclei with prominent eosinophilic nucleoli and some mitotic figures. The neoplastic cells did not show evidence of maturation in deeper areas of the lesion. In some sections, a nodule of heavily pigmented epithelioid melanocytes was seen far from the main bulk of the lesion, at the dermal-subcutaneous interface, raising the possibility of a satellite lesion. A lymphoscintigraphy showed a sentinel lymph node in the right axilla and a subsequent axillary lymphadenectomy demonstrated that the architecture of the sentinel lymph node was effaced by metastatic melanoma. The patient received adjuvant chemotherapy with inteferon alfa-2b and four months after this treatment the patient is alive and well, without evidence of recurrences or additional metastases.
Highly aggressive extraocular sebaceous carcinoma.
Extraocular sebaceous carcinoma is an uncommon neoplasm usually localized on the head and neck. We report a case of sebaceous carcinoma of the axillary skin with a highly aggressive behavior. The patient was a 43-year-old black man who developed multiple cutaneous and lymph node metastases shortly after the excision of primary sebaceous carcinoma of the axillary skin. Many neoplastic aggregations were identified within the lumina of the dermal lymphatic vessels in the excised specimen of the primary neoplasm. Although extraocular sebaceous carcinoma has been traditionally considered a less aggressive neoplasm than its ocular counterpart, a review of the literature and this case demonstrate that extraocular sebaceous carcinoma may also lead to disseminated metastatic disease.
Olmsted syndrome: report of a case with study of the cellular proliferation in keratoderma.
Olmsted syndrome is a rare disorder that consists of sharply marginated keratoderma of the palms and soles, constriction of digits and toes that may result in spontaneous amputation of the distal phalanges, hyperkeratotic plaques around the body orifices, onychodystrophy, and other less common cutaneous and extracutaneous anomalies. Although some patients had other affected family members, most cases of Olmsted syndrome seem to be of sporadic occurrence. We describe a patient with the characteristic features of Olmsted syndrome. The symptoms consisted of diffuse transgrediens palmoplantar keratoderma and keratotic plaques around the mouth and nose. Our patient also had the associated anomalies of hyperhidrosis of the palms and soles and congenital deaf-mutism. Histopathologic study of the keratoderma demonstrated epidermal hyperplasia with acanthosis, papillomatosis, and orthokeratotic hyperkeratosis. Immunohistochemical study showed more basal and suprabasal keratinocytes of the epidermis with immunoreactivity for Ki-67 marker when compared with the keratinocytes of the epidermis of the adjacent non-involved skin. These results support the notion that Olmsted syndrome is a hyperproliferative disorder of the epidermis.
Reconstruction of ocular surface with heterologous limbal epithelium and amniotic membrane in a rabbit model.
PURPOSE: To report in vivo reconstruction of the ocular surface using amniotic membrane and heterologous transplants of epithelial limbal cells in rabbits with chemical burns. METHODS: After severe damage to the ocular surface with n-heptanol and keratectomy, 15 rabbits developed total limbal deficiency with conjunctival epithelialization, vascularization, and chronic inflammation. One month later, a complete keratectomy was performed in all eyes: 12 received additional transplantation of human amniotic membrane and heterologous limbal epithelial cells in a double amniotic membrane layer, 2 received amniotic membrane only, and 1 control eye received no procedure. RESULTS: After 1 month of follow-up, corneas in eight of the operated eyes presented minimal vascularization, without signs of rejection. Corneal surface reconstruction was demonstrated with the growth of new corneal-like epithelial phenotype and integration of amniotic membrane to the basal corneal surface. A superficial amniotic membrane (with the amnion side up as a dressing) peeled off after 7 to 10 days. The epithelialization with heterologous limbal epithelial cells was evident underneath. The other four operated eyes were followed for 6 months; the ocular surface was also stable with a corneal-like epithelial phenotype. CONCLUSION: Simultaneous transplantation of amniotic membrane and heterologous limbal epithelial cells in severe ocular surface disorders could restore ocular surface and may be useful in patients with severe bilateral limbal epithelial loss, giving new perspectives for the treatment of severe ocular surface disorders.
Nutrition communication for a Latino community: formative research foundations.
Formative research techniques were used to develop a tailored health communication nutrition intervention for Latinas and their families. Members of the target community were recruited to participate in focus groups, depth interviews, and participant observations. Women, in particular, were observed preparing meals in their homes and purchasing groceries. The objective was to identify variables that could be used for targeting, segmenting, and tailoring the intervention. Results from these efforts were used to develop a theory-based intervention, which is described at the conclusion of the article.
Role of guanylyl cyclase and cytochrome P-450 on renal response to nitric oxide.
The present study evaluated whether inhibition of guanylyl cyclase (GC) with 1H-(1,2,4)oxadiazolo[4,3-a]quinoxaline-1-one (ODQ) and methylene blue (MB) or inhibition of the renal metabolism of arachidonic acid by cytochrome P-450 (CYP450) enzymes with 1-aminobenzotriazole (ABT) and N-hydroxy-N'-(4 butyl-2-methyl phenyl)formamidine (HET0016) alters the renal tubular and vascular effects of a nitric oxide (NO) donor in vivo. Intrarenal infusion of ODQ or MB at a dose of 170 nmol. kg(-1). min(-1) lowered renal blood flow (RBF) by 30 and 15%, respectively; glomerular filtration rate (GFR) by 26 and 18%, respectively; and sodium and water excretion by approximately 35%. In rats pretreated with nitro-L-arginine methyl ester (37 nmol. kg(-1). min(-1)) to block the endogenous production of NO, intrarenal infusion of the NO donor S-nitroso-N-acetylcysteine (S-NO-NAC; 50 nmol. kg(-1). min(-1)) increased RBF (18%), sodium (73%), and water excretion (61%). ODQ or MB administration blocked the effect of S-NO-NAC on RBF but not the diuretic and natriuretic response. Pretreatment of rats with ABT or HET0016 also abolished the renal vasodilatory response to the NO donor and reduced its diuretic and natriuretic effect. These results indicate that both activation of GC and inhibition of CYP450 enzymes contribute to the renal vascular actions of NO, whereas the natriuretic and diuretic actions of NO appear to be largely CYP450 dependent.
A single strain of Mycobacterium bovis bacillus Calmette-Guérin (BCG) grown in two different media evokes distinct humoral immune responses in mice.
Two attenuated bacillus Calmette-Guérin (BCG) preparations derived from the same Moreau strain, Copenhagen but grown in Sauton medium containing starch and bacto-peptone (onco BCG, O-BCG), or asparagine (intradermal BCG, ID-BCG), exhibited indistinguishable DNA sequences and bacterial morphology. The number of viable bacilli recovered from spleen, liver and lungs was approximately the same in mice inoculated with the vaccines and was similarly reduced (over 90%) in mice previously immunized with either BCG vaccine. The humoral immune response evoked by the vaccines was, however, distinct. Spleen cell proliferation accompanying the growth of bacilli in tissue was significantly higher in mice inoculated with O-BCG. These cells proliferated in vitro upon challenge with the corresponding BCG extract. Previous cell treatment with mAb anti-CD4 T cells abolished this effect. Anti-BCG antibodies, as assayed either in serum by ELISA or by determining the number of antibody-producing spleen cells by the spot-ELISA method, were significantly higher in mice inoculated with ID-BCG. Anti-BCG antibodies were detected in all immunoglobulin classes, but they were more prevalent in IgG with the following distribution among its isotypes: IgG1>(IgG2a = IgG2b)>IgG3. When some well-characterized Mycobacterium tuberculosis antigens were used as substitutes for BCG extracts in ELISA, although antibodies against the 65-kDa and 96-kDa proteins were detected significantly, antibodies against the 71-kDa, 38-kDa proteins and lipoarabinomannan were only barely detected or even absent. These results indicate that BCG bacilli cultured in Sauton-asparagine medium permitted the multiplication of bacilli, tending to induce a stronger humoral immune response as compared with bacilli grown in Sauton-starch/bacto-peptone-enriched medium.
[Severe caustic injuries of the esophagus: when to replace the esophagus].
From June 1985 to May 1998, 20 patients have been treated in our hospital by esophageal dilatations due to serious esophageal caustic stenosis. A retrospective analysis of these 20 patients was performed, evaluating age, sex, causative agent, number and time of dilatations, iatrogenic esophageal perforations, gastroesophageal reflux (GER) and psychological and social consequences. Follow-up has ranged from 1.5 to 14.5 years (mean = 8.07 years). The mean age at the time of accidental swallow was 42.2 months. The causative agent was dishwashing detergent in 11 patients and caustic soda in 9 patients. The mean of dilatations needed was 19.1 and the average duration of dilatations was 24.7 months. Seven patients had esophageal perforation during dilatation and none of them required surgical treatment. All patients had improvement of swallowing and an easier esophageal dilatation afterwards. Oral contrast studies demonstrated distortion of the esophago-gastric junction in the majority of patients. Ten patients were screened for GER with 24-hour esophageal pH monitoring in the first year postburn and it was pathological in 5. Antireflux surgery was carried out in 4 patients with a conspicuous improvement following surgery. Dilatations proved successful in 16 patients in less than two years, and in more than two years in 3 patients. The authors conclude that the majority of children with esophageal caustic stenosis can be managed successfully by esophageal dilatations, even with dilatation periods longer than two years or when an esophageal perforation occur during the procedure. The paramount importance of early diagnosis and treatment of GER is stressed.
Detection of Legionella pneumophila in bioaerosols by polymerase chain reaction.
Most studies focusing on detecting microorganisms in air by polymerase chain reaction (PCR) have used a liquid impinger to sample bioaerosols, mainly because a liquid sample is easy to be processed by PCR analysis. Nevertheless, the use of multiple-hole impactors for the analysis of bioaerosols by PCR has not been reported despite its great utility in culture analysis. In this study we have modified the impaction onto an agar surface sampling method to impaction onto a liquid medium using the MAS-100 air sampler (Merck) (single-stage multiple-hole impactor). To evaluate the recovery of airborne microorganisms of both sampling methods, a suspension containing Escherichia coli was artificially aerosolized and bioaerosols were collected onto Tergitol-7 agar and phosphate-buffered saline (PBS) with the MAS-100. A linear regression analysis of the results showed a strong positive correlation between both sampling methods (r = 0.99, slope 0.99, and y intercept 0.07). Afterwards, the method of impingement into a liquid medium was used to study airborne Legionella pneumophila by PCR. A total of 64 samples were taken at a wastewater treatment plant, a chemical plant, and an office building and analyzed by culture and PCR. Results showed that three samples were positive both by PCR and plate culture, and that nine samples negative by plate culture were positive by PCR, proving that L. pneumophila was present in bioaerosols from these three different environments. The results demonstrate the utility of this single-stage multiple-hole impactor for sampling bioaerosols, both by culture and by PCR.
[Colonic aganglionosis with ileal involvement. Ileocolic plasty].
During 1994 through 1999, we have treated five patients (3 boys, 2 girls) with total colonic aganglionosis (TCA) and ileal involvement. In three of them we performed a diverting ileostomy in the neonatal period and at the age of four and five months respectively in the remaining two patients, due to intestinal obstruction. In these two last patients a diagnosis of Hirschsprung's disease was made by anorectal manometry and rectal biopsies in the neonatal period. During laparotomy, a cutaneous ileostomy was created in all patients at the distal end of normal ileum, which was 30 to 110 cm (mean = 71 +/- 37 cm) from the ileocecal valve. After operation, a short bowel syndrome developed in three patients causing fluid and nutritional problems that required prolonged total parenteral nutrition (TPN). The definitive operative repair is performed at 4.5 to 14 months (mean = 8 +/- 3.7 months) by a 12 to 20 cm side-to-side ileocolostomy created between the ileum and aganglionic ascending color (Boley procedure) and ileorectal primary anastomosis (Rehbein procedure) using a circular stapler. Rectal dilatation, irrigation of the colon with saline, loperamide hydrochloride and resincholestyramine were begun in all patients postoperatively. Oral antibiotic prophylaxis, was given to the three patients who suffered from SBS. Oral feedings with semielemental diet were tolerated once stools were semiformed and TPN was discontinued at 8 to 34 days (mean = 21 +/- 1.7 days). postoperatively. After the definitive operation, enterocolitis developed in two patients, requiring one of them a short hospitalization during the episode. A possible explanation for the low incidence of enterocolitis in this series is the systematic postoperative use of irrigations of the colon with saline in all patients. These five patients have been followed-up for growth, development, bowel habit and continence. Follow-up has ranged from 15 to 62 months (mean = 32.2 +/- 19.2 months). Presently, all patients in this series have full enteral feeding and one to three bowel movements per day, with formed or semiformed stools. No patients is incontinent of stool. The patient's body weights (74 to 93%) and heights (89 to 92%) for their age were below average (four patients) or within normal range (one patient). Hemoglobin levels are within normal range in all patients. One patient has iron deficiency and another one has serum ferritin concentration below normal. Three patients have folic acid deficiency. Vitamin B12 absorption is normal in all patients. Although we can not conclude this is a better procedure than others, with is use we have obtained satisfactory results, with an excellent survival, scanty morbidity, a rapid return of bowel function and continence, and an acceptable physical development. During long-term follow-up, patients mus be evaluated for iron and folic acid deficiency.
Medical abortion: overview and management.
Medical abortion regimens are safe, effective, and offer a new range of choices for patients and providers. In September 2000, the US Food and Drug Administration (FDA) approved a regimen of mifepristone and misoprostol, which effects abortion by luteolysis, uterine contractions, and expulsion of the products of conception without surgical instrumentation. The regimen requires that a provider be capable of diagnosing ectopic gestations and be able to make arrangements for a surgical abortion in the case of failure or medical emergencies. With a medical abortion, the pregnancy is passed spontaneously, and there may not be tissue obtained for confirmation. Physicians must be aware of their state requirements with regard to expulsed tissue examination. Completion of the procedure can be established by ultrasound or by measurement of serum levels of human chorionic gonadotropin (hCG). The FDA-approved protocol allows for use up to 49 days after the first day of the last menstrual period (LMP) and consists of mifepristone 600 mg orally on day 1, misoprostol 400 mcg orally on day 3, and a follow-up appointment on days 12-20. Half of all patients pass their pregnancy in the first few hours after the second visit. It is important to be able to determine the difference between expected bleeding, 14 days on average, and the complication of hemorrhage, as 2% to 10% of patients require a surgical abortion. Continuing viable pregnancies are rare. Several other regimens can safely expand options and reduce expense, including protocols using methotrexate. Medication indications and contraindications, management strategies for patients undergoing treatment with these regimens, and safety issues are reviewed.