Biomedical subjects

H Orozco

Publications and source records attributed to H Orozco.

At least 19 recordsLinked to original sources

PubMed2005

The effects of vetrabutin chlorhydrate and oxytocin on stillbirth rate and asphyxia in swine.

Oxytocin and vetrabutin chlorhydrate (VC) are used to reduce the duration of farrowing in swine. The objective of the present study was to evaluate the use of these products on intra-partum stillbirth (IPS) rate and asphyxia. At the onset of parturition, sows (n=180) were allocated to receive 2 mL of saline (control group), oxytocin (40 IU i.m.) or 100mg of VC per 60 kg of body weight, with all treatments given i.m. Oytocin-treated sows had a higher number of IPS than the VC and Control groups (means, 1.2, 0.8 and 0.6, respectively; P<0.001), and the highest percentage of ruptured umbilical cords (76.0, 9.4 and 37.5%; P<0.003). There were differences among groups for duration of farrowing (means, 163.0, 211.2 and 306.9 min in the oxytocin, VC and control groups; P<0.001), interval between piglets (13.9, 19.2 and 28.1 min; P<0.001), and in IPS, the incidence of ruptured umbilical cords was 76.0, 9.4 and 37.5% (P<0.003) and absence of a fetal heartbeat was 53.3, 16.9 and 12.5% (P<0.05). Although oxytocin decreased both duration of farrowing and interval between piglets by approximately 50% relative to control sows, it resulted in a significantly higher rate of IPS, in association with a much higher incidence of ruptured umbilical cord and absence of a fetal heartbeat. Treatment with VC reduced farrowing duration by approximately 1.5h, with an IPS rate that was not significantly different from controls but significantly lower than that of oxytocin-treated sows.

Animals↗

PubMed2003

Acute bile duct injury. The need for a high repair.

BACKGROUND: An immediate repair is considered optimal in acute biliary duct injuries; however, it may prove to be a challenge, because such repairs are usually performed on small ducts whose viability cannot always be determined. METHODS: We performed a retrospective review of the charts of patients with acute bile duct injury who underwent repair at a tertiary care academic university hospital. A total of 204 patients with acute bile duct injury were seen between 1989 and 2002. Of these, 30 were repaired within minutes to hours after the injury. These patients were divided into two groups. Group I patients had a Roux-en-Y hepatojejunostomy below the hepatic junction; Group II patients had a Roux-en-Y hepatojejunostomy at the junction level. We then performed a long-term evaluation of anastomosis function in these patients, using clinical, radiological, and laboratory. RESULTS: Twenty-eight injuries were secondary to a laparoscopy; the other two resulted from open cholecystectomies. All of the patients suffered complex injuries with complete section of the duct and substance loss (Strasberg E). There were 12 patients in group I and 18 in group II. Three cases in group I (25%) and one in group II (5%) developed anastomosis dysfunction. Mean follow-up was 56 months (range, 12-80) in group I and 52 months (range, 10-76) in group II. Two cases in group I (16%) and none in group II (0) required reoperation (p < 0.05). CONCLUSIONS: In the acute setting, complex lesions should be treated with a high bilioenteric anastomosis (at the junction level) in the first attempt at repair. Lower-level anastomoses are associated with a higher dysfunction rate and the need for radiological manipulation and reoperation. Also, stenosis of the anastomosis secondary to undetected duct ischemia in the acute repair is more frequent in low bilioenteric anastomoses.

Acute Disease↗

PubMed2003

A marked difference in pathogenesis and immune response induced by different Mycobacterium tuberculosis genotypes.

In the last decade, an unprecedented genetic diversity has been disclosed among Mycobacterium tuberculosis strains found worldwide. However, well-conserved genotypes seem to prevail in areas with high incidence of tuberculosis. As this may be related to selective advantages, such as advanced mechanisms to circumvent [M. bovis Bacille Calmette-Guerin (BCG)-induced] host defence mechanisms, we investigated the influence of strain diversity on the course of experimental disease. Twelve M. tuberculosis strains, representing four major genotype families found worldwide today, and the laboratory strain H37Rv were each used to infect BALB/c mice by direct intratracheal injection. Compared with H37Rv, infections with Beijng strains were characterized by extensive pneumonia, early but ephemeral tumour necrosis factor-alpha (TNF-alpha) and inducible isoform of nitric oxide synthetase (iNOS) expression, and significantly higher earlier mortality. Conversely, Canetti strains induced limited pneumonia, sustained TNF-alpha and iNOS expression in lungs, and almost 100% survival. Strains of the Somali and the Haarlem genotype families displayed less homogeneous, intermediate rates of survival. Previous BCG vaccination protected less effectively against infection with Beijing strains than against the H37Rv strain. In conclusion, genetically different M. tuberculosis strains evoked markedly different immunopathological events. Bacteria with the Beijing genotype, highly prevalent in Asia and the former USSR, elicited a non-protective immune response in mice and were the most virulent. Future immunological research, particularly on candidate vaccines, should include a broad spectrum of M. tuberculosis genotypes rather than a few laboratory strains.

Animals↗

PubMed2001

Ontogeny and subcellular localization of rat liver mitochondrial branched chain amino-acid aminotransferase.

Branched chain amino-acid aminotransferase (BCAT) activity is present in fetal liver but the developmental pattern of mitochondrial BCAT (BCATm) expression in rat liver has not been studied. The aim of this study was to determine the activity, protein and mRNA concentration of BCATm in fetal and postnatal rat liver, and to localize this enzyme at the cellular and subcellular levels at both developmental stages. Maximal BCAT activity and BCATm mRNA expression occurred at 17 days' gestation in fetal rat liver and then declined significantly immediately after birth. This pattern was observed only in liver; rat heart showed a different developmental pattern. Fetal liver showed intense immunostaining to BCATm in the nuclei and mitochondria of hepatic cells and blood cell precursors; in contrast, adult liver showed mild immunoreactivity located only in the mitochondria of hepatocytes. BCAT activity in isolated fetal liver nuclei was 0.64 mU x mg(-1) protein whereas it was undetectable in adult liver nuclei. By Western blot analysis the BCATm antibody recognized a 41-kDa protein in fetal liver nuclei, and proteins of 41 and 43 kDa in fetal liver supernatant. In adult rat liver supernatant, the BCATm antibody recognized only a 43-kDa protein; however, neither protein was detected in adult rat liver nuclei. The appearance of the 41-kDa protein was associated with the presence of the highly active form of BCATm. These results suggest the existence of active and inactive forms of BCAT in rat liver.

Animals↗

PubMed2000

The evolution of portal hypertension surgery: lessons from 1000 operations and 50 Years' experience.

HYPOTHESIS: Surgery for portal hypertension has evolved widely in the past decades. Selection criteria and the type of operations have evolved because of the appearance of other therapeutic alternatives, such as pharmacotherapy, endoscopic therapy, transjugular intrahepatic portosystemic shunt, and liver transplantation. We believe the surgical approach has a therapeutic role in a select patient population. DESIGN: Retrospective review of the medical records of patients operated on for bleeding portal hypertension in the past 50 years. SETTING: An academic tertiary care university hospital. PATIENTS AND METHODS: In a 50-year period, 1000 operations for the treatment of bleeding portal hypertension have been done, including shunts and devascularization procedures. In the past years, in low-risk (Child-Pugh classification A) selected patients, only portal blood flow-preserving operations have been done. RESULTS: Non-portal blood flow-preserving procedures had a wide spectrum of results, with a high encephalopathy rate and short long-term survival. The results with portal blood flow-preserving procedures in the past 10 years are as follows: operative mortality, 2.7%; postoperative encephalopathy, 6%; rebleeding, 6%; and shunt obstruction, 4%. CONCLUSIONS: Portal hypertension surgery has a role in elective operations and in low-risk selected patients, when portal blood flow-preserving procedures are done. The type of operation is selected according to the individual characteristics of each patient.

Gastrointestinal Hemorrhage↗

PubMed2000

Surgery in Mexico.

Explore the source record for details and available documents.

General Surgery↗

PubMed2000

Liver cirrhosis is reverted by urokinase-type plasminogen activator gene therapy.

Liver cirrhosis represents a worldwide health problem and is a major cause of mortality. Cirrhosis is the result of extensive hepatocyte death and fibrosis induced by chronic alcohol abuse and hepatitis B and C viruses. Successful gene therapy approaches to this disease may require both reversal of fibrosis and stimulation of hepatocyte growth. Urokinase-type plasminogen activator (uPA) may serve this function, as it is an initiator of the matrix proteolysis cascade and induces hepatocyte growth factor expression. In a rat cirrhosis model, a single iv administration of a replication-deficient adenoviral vector encoding a nonsecreted form of human uPA resulted in high production of functional uPA protein in the liver. This led to induction of collagenase expression and reversal of fibrosis with concomitant hepatocyte and improved liver function. Thus, uPA gene therapy may be an effective strategy for treating cirrhosis in humans.

Animals↗

PubMed2000

Treatment with BB-94, a broad spectrum inhibitor of zinc-dependent metalloproteinases, causes deviation of the cytokine profile towards type-2 in experimental pulmonary tuberculosis in Balb/c mice.

BB-94 (batimastat) is a broad- spectrum hydroxamic acid-based zinc metalloproteinase inhibitor that inhibits both the matrix metalloproteinases (MMP) and members of the ADAM family of enzymes such as Tumour Necrosis Factor-alpha Cleaving Enzyme (TACE). These enzymes are involved in the regulation of inflammatory processes in tuberculosis. Balb/c mice infected with M. tuberculosis via the intratracheal route were treated with BB-94 for 1 month, starting on the day of infection. Immunohistochemistry, semiquantitative RT-PCR and ELISA assays for cytokines revealed a deficit in IL-1 and IL-2 expression and a premature bias towards IL-4 expression, accompanied by a delay in granuloma formation and more rapid progression of disease in BB-94-treated animals. This situation corrected itself after the drug was withdrawn at 28 days. In contrast, when BB-94 was administered only after 1 month there were no significant changes apart from the presence of amyloid, and a paradoxically increased expression of IL-1alpha. These results cast light on mechanisms of immunity in tuberculosis and also indicate that in patients treated with similar broad-spectrum MMP inhibitors there may be a risk of inappropriate deviation of some immune responses towards a Type-2 cytokine profile.

Animals↗

PubMed2000

A comparative study of the elective treatment of variceal hemorrhage with beta-blockers, transendoscopic sclerotherapy, and surgery: a prospective, controlled, and randomized trial during 10 years.

OBJECTIVE: To compare three options for the elective treatment of portal hypertension during a 10-year period. METHODS: Patients included in the trial were 18 to 76 years old, had a history of bleeding portal hypertension, and had undergone no prior treatment. Treatment options were beta-blockers (propranolol), sclerotherapy, and portal blood flow-preserving procedures (selective shunts and the Sugiura-Futagawa operation). RESULTS: A total of 119 patients were included: 40 in the pharmacology group, 46 in the sclerotherapy group,and 33 in the surgical group. The three groups showed no differences in terms of age, Child-Pugh classification, and cause of liver disease. The rebleeding rate was significantly lower in the surgical group than in the other two groups. The rebleeding rate was only 5% in the Child A surgical group, compared with 71% and 68% for the sclerotherapy and pharmacotherapy groups, respectively. Survival was better for the low-risk patients (Child A) in the three groups, but when the three options were compared, no significant difference was found. CONCLUSIONS: Portal blood flow-preserving procedures offer the lowest rebleeding rate in low-risk patients undergoing elective surgery.

Adolescent↗

PubMed1999

Biliary duct injury: partial segment IV resection for intrahepatic reconstruction of biliary lesions.

A technique for intrahepatic reconstruction of the biliary tree after complex high injuries is described. The fundament of the procedure is the removal of a wedge of segment IV at the level of the hilar plate. When the hilar plate is reached and no adequate exposure of the ducts can be obtained, removing a 1 x 1-in wedge of segment IV between the gallbladder bed and the round ligament exposes the left and right ducts. An anteroposterior view of the plate is obtained instead of a caudocephalic dissection, exposing healthy, nonscarred ducts for reconstruction. We have used this approach in 22 patients, and adequate exposure of the ducts has been obtained, with a high success rate of patency of the anastomosis at a mean follow-up of 3 years. Twenty patients have a patent anastomosis, with a good quality of life and no restenosis.

Adult↗

PubMed1999

Results of surgical treatment (modified Sugiura-Futagawa operation) of portal hypertension associated to complete splenomesoportal thrombosis and cirrhosis.

BACKGROUND: Hemorrhagic portal hypertension, secondary to both intrahepatic and extrahepatic portal hypertension, is an uncommon entity. In this condition, the extrahepatic and the intrahepatic obstruction of the portal vein, due to chronic liver disease, produce a more severe form of hemorrhagic portal hypertension that is more difficult to control. The results of surgical treatment (modified Sugiura-Futagawa operation) in this subset of patients is analyzed. METHODS: Among 714 patients with a history of hemorrhagic portal hypertension, 14 cases were found with histologically proven liver cirrhosis and complete splenomesoportal thrombosis demonstrated by means of preoperative angiography. Patients with incomplete (partial) splenomesoportal thrombosis were excluded. There were nine males and 5 females with a mean age of 51 years. Alcoholic cirrhosis was demonstrated in 50% of the cases, post hepatitic cirrhosis in 28%, primary biliary cirrhosis in 7%, and cryptogenic cirrhosis in 14%. There were nine Child-Pugh A and 5 B cases. All cases were treated by means of our modified Sugiura-Futagawa procedure. RESULTS: Bleeding recurrence from esophagogastric varices was shown in one case, colonic varices in one case and hypertensive gastropathy in another of the survivors. Post operative encephalopathy was shown in 3 of the cases. The thirty-six month survival rate was 30% (Kaplan-Meier). CONCLUSIONS: The combination of intrahepatic plus extrahepatic portal hypertension has a worse prognosis. Treatment options are limited (sclerotherapy and/or devascularization), because shunt surgery, TIPS and liver transplantation have a very restricted role and postoperative outcome is poor.

Adolescent↗

PubMed1999

Reoperations for bleeding portal hypertension. Surgical rescue of surgical failures.

BACKGROUND: Surgery for portal hypertension has a low rebleeding rate. Patients that rebleed can be grossly divided into those who die as a consequence of the episode, those who don't die but develop liver failure (remaining as Child-Pugh C) and those who, in spite of the bleeding episode, retain good liver function (Child-Pugh A or B). At our hospital, the latter group is considered for further surgical treatment. We report here the results of surgical rescue of surgical failures. METHODS: In a twenty year period, 36 patients (30 Child-Pugh A, 6 Child-Pugh B) were reoperated. The files of these patients were reviewed. RESULTS: Average age was 33 years. Cirrhosis was present in 31 cases. All patients were electively reoperated with portal blood flow preserving procedures. Operative mortality for the whole group was 12% and for the Child-Pugh A group 6.6%. Rebleeding was observed in 5.5%. Postoperative incapacitating encephalopathy was recorded in one case (2.7%). Good quality of life was recorded in 84% of the cases. Survival (Kaplan-Meier) was 78% at 6 months and 69% at 5 years. CONCLUSIONS: Surgical failures in low risk patients (Child-Pugh A or B) can be treated by means of surgery, and a low mortality, re-bleeding and encephalopathy rate can be expected. The performance of a portal blood flow preserving procedure is recommended.

Adolescent↗

PubMed1998

Is splenectomy necessary in devascularization procedures for treatment of bleeding portal hypertension?

OBJECTIVE: To investigate whether splenectomy as a part of devascularization procedures is necessary. DESIGN: Prospective, controlled, randomized trial. SETTING: University hospital, referral center. PATIENTS: A total of 55 patients (Child-Pugh class A and B) with a history of bleeding portal hypertension were treated by means of a modified Sugiura-Futagawa procedure. Twenty-three patients underwent splenectomy and 22 did not. METHODS: Postoperative outcome was recorded and comparison of the 2 groups was done with the Fisher exact test. Kaplan-Meier survival curves were constructed. Main outcome and postoperative differences between the patients who underwent splenectomy and those who did not were investigated. RESULTS: Both groups were comparable in the postoperative period. Significant differences were observed in transfusion requirements and postoperative portal vein thrombosis, both favoring the group without splenectomy. No differences in rebleeding, encephalopathy rate, operative time, or postoperative complications were observed. CONCLUSION: Splenectomy is not routinely necessary in devascularization procedures for bleeding portal hypertension.

Adolescent↗

PubMed1998

Comparative study of 2 variants of a modified esophageal transection in the Sugiura-Futagawa operation.

OBJECTIVE: To compare 2 techniques of esophageal transection in our modification of the Sugiura-Futagawa procedure for the treatment of bleeding portal hypertension in low-risk patients who cannot undergo surgery to have shunts placed. DESIGN: A prospective controlled trial comparing 2 variants of transection (classic, complete section of the anterior muscularis externa and whole mucosa; modified, placement of a circumferential running suture without opening the mucosa). SETTING: Academic university hospital. PATIENTS: Eighty-three low-risk patients (Child-Pugh score A and B) with a history of bleeding portal hypertension were operated on (35 classic, 48 modified transections) between 1989 and 1996. Both groups were comparable. MAIN OUTCOME MEASURES: Postoperative dehiscence of the transection was evaluated as well as fistulization, postoperative stenosis, rebleeding, postoperative endoscopic findings, survival, and mortality. RESULTS: Fistulization was observed in 1 (2%) of the patients in the modified group, and dehiscence in 1 patient (2%). In the classic group, 3 (8%) of the patients had dehiscence (relative risk, 2.6) and 1 (2%) of the patients, fistulization. No differences were observed regarding rebleeding (6 patients [6%] vs 5 patients [7%]), postoperative stenosis (4 patients [8%] vs 5 patients [10%]), postoperative endoscopic findings, survival, and mortality (early and late). CONCLUSION: The modified variant of the transection has a lower frequency of postoperative dehiscence, with the same long-term results.

Esophageal and Gastric Varices↗

PubMed1998

The effects of androstenediol and dehydroepiandrosterone on the course and cytokine profile of tuberculosis in BALB/c mice.

Immunity to Mycobacterium tuberculosis requires a T helper 1 (Th1) cytokine balance accompanied by tumour necrosis factor-alpha (TNF-alpha), and activated macrophages. These facets of the immune response are sensitive to suppression by glucocorticoids (GC), which can reactivate and exacerbate tuberculosis in man and animals. Dehydroepiandrosterone (DHEA) and its derivative, 3beta,17beta androstenediol (AED), are reported to have antiglucocorticoid properties in vivo. We therefore investigated the effects of predetermined optimal doses of these compounds, on the course of pulmonary tuberculosis in an established model in BALB/c mice in which an early phase of Th1-mediated response accompanied by adrenal hyperplasia, is followed by a switch to Th2, progressive loss of TNF-alpha expression and disease progression. Both compounds were protective, particularly AED which caused a fall in bacterial counts and prolonged survival. These effects correlated with the appearance within 3 days of cellular infiltrates rich in cells expressing interleukin-2 (IL-2), IL-1alpha and TNF-alpha, and with partial suppression of the switch to IL-4 producing cells that occurred in controls. AED also caused enhanced development of granulomas at 14 days, and persistence of granuloma formation to 120 days, with a corresponding suppression of areas affected by pneumonia. Much of the therapeutic effect of AED and DHEA was obtained by treating for only the first 3 weeks, which is the phase of adrenal hyperplasia. These results suggest that the ratio of GC to anti-GC steroids may play a role in the pathogenesis of tuberculosis, and further investigation could lead to novel treatment strategies.

Androstenediol↗

PubMed1998

Emergent immunoregulatory properties of combined glucocorticoid and anti-glucocorticoid steroids in a model of tuberculosis.

In Balb/c mice with pulmonary tuberculosis, there is a switch from a protective Th1-dominated cytokine profile to a non-protective profile with a Th2 component. This switch occurs while the adrenals are undergoing marked hyperplasia. Treatment with the anti-glucocorticoid hormones dehydroepiandrosterone or 3 beta, 17 beta-androstenediol, during the period of adrenal hyperplasia, maintains Th1 dominance and is protective. We investigated the effects of these hormones as therapeutic agents by administering them from day 60, when the switch to the non-protective cytokine profile was already well established. Given at this time (day 60), doses that were protective when given early (from day 0) were rapidly fatal. A physiological dose of the glucocorticoid corticosterone was also rapidly fatal. However when the corticosterone and the anti-glucocorticoid (AED or DHEA) were co-administered, there was protection, with restoration of a Th1-dominated cytokine profile, enhanced DTH responses, and enhanced expression of IL-1 alpha and TNF alpha. Therefore this combination of steroids has an emergent property that is quite unlike that of either type of steroid given alone. It may be possible to exploit the ant-inflammatory properties of glucocorticoids while preserving a Th1 bias, by combining glucocorticoids with DHEA or suitable metabolites.

Adjuvants, Immunologic↗

PubMed1997

Surgery in elderly patients in Mexico. Portal hypertension surgery as an example.

Although people older than 65 years represent less than 5% of Mexico's registered population, medical care for elderly patients requires a multidisciplinary approach. In our academic university hospital, they are managed by a team of specialists. As an example of this approach, we evaluated the surgical treatment of bleeding portal hypertension in a highly selected elderly population. A retrospective study was done reviewing the files of 25 patients older than 65 years. All had good liver function (Child-Pugh class A and B) and had undergone elective surgery. Sixteen of them were women. The mean age was 68.8 years (age range, 65-76 years), and most had a diagnosis of cirrhosis. All patients were treated with portal blood flow-preserving procedures (selective shunts or Sugiura-Futagawa procedures). The operative mortality was 8%. Eight later deaths were recorded, with a mean follow-up of 25 months (range, 2-110 months). Survival (Kaplan-Meier) was 87% at 12 months, 54% at 60 months, and 45% at 110 months. Two rebleeding incidents were recorded as well as 3 cases of postoperative encephalopathy. We concluded that well-selected elderly patients, undergoing elective surgery with portal blood flow-preserving procedures, have a good postoperative outcome.

Age Factors↗

PubMed1997

Selective shunts for portal hypertension: current role of a 21-year experience.

The results of treatment of hemorrhagic portal hypertension with selective shunts over a 21-year period in a selected patient population are reported. Patients selected for surgical treatment had good cardiopulmonary and renal function, and most also had adequate liver function (141 Child-Pugh class A, 59 class B). Among 734 patients treated surgically for bleeding portal hypertension, 221 had selective shunts (168 distal splenorenal and 53 splenocaval shunts). Global operative mortality (in the 21-year period) was 14% and 12% for Child-Pugh A patients. Operative mortality in Child-Pugh A patients in the last 5 years was only 5%. The rate of rebleeding was 6%, rate of incapacitating encephalopathy was 5%, and rate of survival was 65% at 15 years (last 5 years: 88% at 1 year and 85% at 5 years). Good quality of life was demonstrated in 80% of surviving patients. Shunt patency was 94%. Postoperative portal blood flow changes occurred in 23% of cases (8% diameter reduction, 14% thrombosis). Compared with other forms of therapy (pharmacotherapy, sclerotherapy, and transjugular intrahepatic shunting), only liver transplantation offers similar results for these patients. In countries in which liver transplantation is not routinely performed, shunting with selective shunts is the treatment of choice for patients with good liver function.

Angiography↗