The bibliometric landscape of infectious disease research in Panama (1990-2019)

Background

This work aims to analyze the landscape of scientific publications on subjects related to One Health and infectious diseases in Panama. The research questions are: How does the One Health research landscape look like in Panama? Are historical research efforts aligned with the One Health concept? What infectious diseases have received more attention from the local scientific community since 1990?

Methods

Boolean searches on the Web of Science, SCOPUS and PubMed were undertaken to evaluate the main trends of publications related to One Health and infectious disease research in the country of Panama, between 1990 and 2019.

Results

4546 publications were identified since 1990, including 3564 peer-reviewed articles interconnected with One Health related descriptors, and 211 articles focused particularly on infectious diseases. A pattern of exponential growth in the number of publications with various contributions from Panamanian institutions was observed. The rate of multidisciplinary research was moderate, whereas those of interinstitutional and intersectoral research ranged from low to very low. Research efforts have centered largely on protozoan, neglected and arthropod-borne diseases with a strong emphasis on malaria, Chagas and leishmaniasis.

Conclusion

Panama has scientific capabilities on One Health to tackle future infectious disease threats, but the official collaboration schemes and strategic investment to develop further competencies need to be conciliated with modern times, aka the pandemics era. The main proposition here, addressed to the government of Panama, is to launch a One Health regional center to promote multidisciplinary, interinstitutional and intersectoral research activities in Panama and beyond.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Análisis de los perfiles de investigadores de Panamá e indicadores bibliométricos de Google Scholar

El objetivo de este artículo es evaluar la visibilidad de los investigadores de Panamá y el impacto de sus publicaciones utilizando indicadores bibliométricos como h-index, i10-index y citas de los perfiles en Google Scholar Citations (GSC) categorizados por sexo, institución, miembro del SNI. Para la recolección automática de datos en GSC se creó un algoritmo en el lenguaje R que extrajo 860 perfiles de 47 instituciones, el 25,5% de los perfiles no se contabilizaron citas, el 29,5% tiene un h-index mayor a 5. De los 14.530 trabajos extraídos de los perfiles, 49,3% ha sido citado una vez generando 287.616 citas, 62% de las citas son de trabajos de 28 investigadores. Existe visibilidad de los investigadores de Panamá en GSC, pero solo el 3,3% aporta el 62% de las citas, poco impacto en las publicaciones y errores de indexación, esto sugiere crear políticas institucionales para normalizar la creación de los perfiles.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Bridge therapy in hepatocellular carcinoma before liver transplantation: the experience of two Chilean centers

BACKGROUND

Orthotopic liver transplantation (OLT) is currently an established therapy for small, early-stage hepatocellular carcinoma (HCC) within the Milan criteria. Long waiting times due to the shortage of donor organs can result in tumor progression and drop-out from OLT candidacy. Therefore a wide variety of procedures are necessary before OLT. The aim of this retrospective study was to review our experience in relation to bridge therapy prior to OLT for HCC.

METHODS

This was a retrospective database review of all of the patient who underwent transplantation in our institutions between January 1993 and June 2009. We analyzed patients with a diagnosis of HCC in the explant.

RESULTS

Among 29 patients, including 12 who were diagnosed by the explant and 17 prior to transplantation, 88% underwent bridge therapy during a mean waiting time to OLT of 12 months. Among the 23 procedures, namely 1.5 procedures per patient, included most frequently chemoembolization (48%), alcohol ablation (30%), radiofrequency ablation (13%), and surgery (9%). Thirty-three percent of the explants contained lesions within the Milan criteria. In our series the 5-year survival rate for patients transplanted for HCC was 86%; in the bridge therapy group, it was 73%.

CONCLUSIONS

The incidence of patients who underwent bridge therapy (52%) was similar to other reported experiences, but the fulfillment of Milan criteria in the explants was lower. Among the bridge therapy group, the survival was slightly lower, probably because this group displayed more advanced disease.

First Report of Black Rot on Arugula Caused by Xanthomonas campestris pv. campestris in Argentina

During the fall of 2005, arugula (Eruca sativa Mill.) plants grown in experimental field plots in Buenos Aires, Argentina presented V-shaped necrotic lesions on leaf margins and blackened veins with broad yellow halos, followed by leaf necrosis. At flowering, 96% of the plants were affected with 27% of the leaves with symptoms. Yellow, round, mucoid, convex, bacterial colonies were isolated from several leaves on yeast dextrose chalk agar. Two strains were further studied. Xanthomonas campestris pv. campestris Xcc8004 was used as a control. Strains were gram negative, rod shaped, strictly aerobic, catalase-positive, oxidase and urease-negative, hydrolyzed starch, gelatine and aesculin, and did not reduce nitrate (2). Pathogenicity was tested by spraying 10 3-week-old arugula plants with either a bacterial suspension (10⁷ CFU/ml) or sterile water. Plants were placed in plastic bags for 72 h after inoculation. All inoculated plants showed necrotic lesions enlarging from the margin of the leaves 7 days after inoculation. No lesions were observed on control plants. On the basis of biochemical characterization (2) and genomic fingerprints generated by BOX-PCR (1), the pathogen was identified as X. campestris pv. campestris. To our knowledge, this is the first report of X. campestris pv. campestris causing black rot on arugula in Argentina. References: (1) J. L. Rademaker et al. Int. J. Syst. Evol. Microbiol. 50:665, 2000. (2) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. The American Phytopathological Society, St. Paul, MN, 2001.

Bezoar gástrico como complicación de la cirugía de obesidad mórbida. Caso clínico y revisión de la bibliografía

In the last few years bariatric surgery has become an excellent therapeutic alternative for the treatment of morbid obesity. Food bezoar as a cause for obstruction seems to be a very infrequent postoperative complication. It has only been published as anecdotal case reports. We describe a female patient with morbid obesity (weight, 131 kg; body mass index, 45) who underwent laparoscopic bariatric surgery (subtotal 95% gastrectomy with gastroyeyunoanastomosis in Roux-Y) obtaining a significant weight reduction (51 kg) in the next few months post surgery. She developed a food bezoar in the gastric remnant as a late complication of surgery (13 months after bariatric surgery) and presented as a gastric outlet acute obstruction with persistent vomiting and satiety. The diagnosis and treatment was performed through an upper GI endoscopy. It is important to consider this complication in patients with persisting vomiting after this kind of surgery. In the near future we will probably have a significant amount of patients operated due to morbid obesity and we may see this kind of complication more frequently.

First Report of Downy Mildew of Arugula Caused by Peronospora parasitica in Argentina

Acreage of arugula (Eruca sativa), a crucifer used as a component of green salad mixes, has increased recently in Argentina. During 2004, a foliar disease affected commercial crops in Pilar (northeast of Buenos Aires Province). Arugula plants were affected from the seedling stage to harvest. Severely diseased plants were unmarketable and not harvested. Sunken, round, necrotic lesions (1 to 4 mm in diameter) were observed on the cotyledons. Diseased leaves had irregular, necrotic lesions (2 to 3 mm in diameter) that sometimes became confluent, forming a linear pattern. Necrotic tan patches developed on older leaves. Lesions on the abaxial surface appeared depressed and a gray mold, a typical sign of a downy mildew, was visible. Sporangiophores had dichotomous branches ending in slender curved tips. Sporangia were ovoid with a mean length of 20 μm (17.8 to 22.1 μm) and a mean width of 16 μm (14 to 18.2 μm). Pathogenicity tests were conducted by placing excised diseased leaves onto healthy 30-day-old arugula plants (1). Inoculated plants were placed in plastic bags, previously sprayed with water, for 48 h and maintained in the greenhouse thereafter. Downy mildew symptoms and signs that were similar to those observed in the fields developed 10 days after inoculation. The pathogen was identified as Peronospora parasitica (2). To our knowledge, this is the first report of P. parasitica on arugula in Argentina. References: (1) S. T. Koike. Plant Dis. 82:1063, 1998. (2) W. D. Yerkes and C. G. Shaw. Phytopathology 49:499, 1959.

Rapid steroid taper and neoral monotherapy in liver transplantation in Chile: a step in the right direction?

Diabetes, hypercholesterolemia, hypertension, obesity, osteopenia, and increased risk of viral recurrence are among the complications associated with posttransplant steroid use. Steroid withdrawal or rapid taper has been reported to be safe. The aim of this study was to compare the rejection incidence and severity among patients treated with two different steroid taper strategies.

METHODS

This retrospective study included all the adult liver transplant recipients since the program's inception from 1993 to January 2002. The minimum follow-up was 1 year. Exclusions included patients receiving an immunosupressive regimen other than mycophenolate mofetil, steroids, and Neoral, or suffering an autoimmune etiology, or displaying patient or graft survival less than 1 year. The incidence and severity of rejection episodes were compared between the two groups of steroid taper protocols: group A received methylprednisolone (1 g) intraoperatively with a slow taper to 10 mg prednisone per day at 1 year. Group B received methylprednisolone (2 g) intraoperatively followed by a rapid reduction with intention to withdraw by month 4, continuing on Neoral monotherapy. Rejection diagnosis was made on histological bases.

RESULTS

One-month and 1-year rejection rates were 47% and 53%, respectively, among the rapid taper group with Neoral monotherapy, which was similar to 60% and 64%, respectively, in the slow taper group. Rejection severity was also comparable between the two groups.

CONCLUSIONS

Patients treated with a rapid steroid taper protocol followed by Neoral monotherapy or a slow taper protocol showed similar acute rejection incidences and severities. Their survival rates were also comparable. Further study is necessary to evaluate the impact of rapid steroid taper to prevent the complications of steroid use.

Predictive models in cirrhosis: correlation with the final results and costs of liver transplantation in Chile

Medical scores for predicting survival are essential to stratify patients with end-stage liver disease (ESLD) for prioritization for liver transplantation (OLT). Recently the UNOS has adopted the Mayo Model for End-stage Liver Disease (MELD) score as the basis for liver allocation in the United States. We retrospectively evaluated and assessed the prognostic impact, the length of stay (LOS), and hospital charges for OLT using two severity scores (Child-Turcotte-Pugh [CTP] versus MELD) to stratify cirrhotic patients before OLT. Twenty-six consecutive adult cirrhotic patients (11 women, mean age 46 years) underwent LT between 2000 and 2002. The main causes for transplantation were alcohol and primary biliary cirrhosis. The mean CTP and MELD scores at the moment of listing for OLT were 8.9 and 16.3 points, respectively. The best discriminative values with prognostic impact in terms of outcome and costs of OLT were a Child Pugh score >/=11 points or a MELD score >/=20 points. Patients in these strata showed a significant increase in LOS in the hospital (from a mean of 12 to 22 days) and intensive care stay (from a mean of 4 to 14 days) post-OLT when compared with patients with a lower CTP or MELD score (P <.05). There was also a trend toward higher hospital charges (P =.06). Organ allocation by MELD score will probably adversely affect the LOS and hospital charges of patients being transplanted due to ESLD.

First Report of White Rust of Arugula Caused by Albugo candida in Argentina

Production of arugula (Eruca sativa) has increased greatly in Argentina. Since 2002, particularly during the fall, a foliar disease has affected commercial crops in Capilla del Señor (northeast of Buenos Aires Province, Argentina). The disease appeared in foci, spreading throughout the whole production field or greenhouse. Severely affected crops were plowed under. Diseased leaves were chlorotic and had white sori that emerged through the abaxial epidermis. Sori corresponded to the white rust agent, Albugo candida (Pers.) Kunze (1). Sporangiophores were hyaline and clavate, and sporangia were globose and hyaline with a mean diameter of 16.2 μm (14.2 to 19.2 μm). Pathogenicity tests were performed by spraying a suspension of 10⁶ zoospores/ml or 5 × 10⁴ sporangia/ml on four healthy 30-day-old arugula plants. Inoculum was prepared by scrapping sporangia from infected leaves. Sporangia were used directly or incubated in sterile distilled water (SDW) for 14 h at 5°C to induce zoospore formation (2). Four additional healthy plants were sprayed with SDW to serve as controls. Plants were kept in plastic bags for 48 h and maintained in the greenhouse thereafter. White rust symptoms, similar to those observed on the original plants from the field, were observed on inoculated plants 10 days after inoculation. To our knowledge, this is the fist report of A. candida on arugula in Argentina. References: (1) K. Mukerji. No. 458 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1975. (2) H. Scheck and S. Koike. Plant Dis. 83:877, 1999.

A decade of adult liver transplantation in a single center in Chile

INTRODUCTION

Since the early days, liver transplantation (OLT) has conquered several barriers worldwide to become a proven therapy. We assessed the evolution of our adult liver transplant program.

METHODS

We studied all adult patients who underwent OLT since the inception from November 1993 through May 2003. Donor data, recipient pretransplantation evaluation, surgical technique, results, and costs were examined over our evolution, stratifying 3 groups over time, based on the number of adult OLT per year.

RESULTS

Between November 1993 and May 2003, 70 OLT were performed in 64 patients older than 15 years of age. Preoperative Child score, preoperative creatinine level, donor and recipient age, and proportion of emergencies were similar in the 3 groups. Over time, the predominant surgical technique was the piggyback technique (97% of OLT) with a decrease in the use of bypass from 63% to 5% during the last time period. Over the 10 years of our program's existence, warm ischemia time has been reduced to less than 1 hour, whereas cold ischemia time has remained constant at around 5 hours. Biliary and vascular complications decreased over time to around 10%. The mean length of hospital stay (LOS) decreased to 12 days (excluding emergencies). Since inception, our 1-year patient survival rate average is 91%; however, in just the last 3 years of our program (2000 through 2003), the 1-year patient survival rate is 97%.

CONCLUSIONS

In summary, our surgical technique has evolved toward piggyback use without veno-venous bypass with a significant decrease in warm ischemia times. As expected, our results have improved over time and our LOS and costs have decreased. Finally, our current results are similar to the best ones reported in the medical literature today.

Transcystic cholangiogram access via rubber band with early withdrawal after liver transplantation: A safe technique

OBJECTIVE

Since different techniques have been described for cholangiogram access after liver transplantation, we compared two different methods for patients with duct-to-duct biliary anastomoses.

METHODS

Adult liver transplant patients from program inception in 1993 to May 2003 in whom a duct-to-duct biliary anastomosis with a T-tube choledochostomy were compared with those having a transcystic duct catheter using a rubber band. We excluded 10 patients in which a different technique was used or graft or patient survived less than 21 days. Group A (n = 28,) had a number 10 T-tube exteriorized through the recipient main bile duct; and group B (n = 33) a number 5 Bard ureteral stent tied to the cystic stump with reabsorbable suture and secured with a hemorrhoidal rubber ligature.

RESULTS

The biliary complication rate was lower among the transcystic catheter group (9.1%, 3/33) compared to the T-tube group (35.7%, 10/28). Postcatheter withdrawal peritonitis was present in two patients in the T-tube group, one of whom required emergency laparotomy. A satisfactory postoperative cholangiogram was obtained in both groups. The transcystic catheter was withdrawn on average at 29 days, compared to 136 days in the T-tube group.

CONCLUSIONS

Both techniques are equally effective in obtaining a satisfactory postoperative cholangiogram. However, the transcystic catheter technique allows a significantly earlier withdrawal with fewer complications compared to the T-tube technique.

Clinical characterization and survival of adult patients awaiting liver transplantation in Chile

Liver transplantation has become widely used for patients with decompensated disease. Because of the shortage of donors, each year more patients die on the waiting list. Our aim was to characterize and evaluate the final outcomes of all listed candidates for liver transplantation during a 34-month period. We retrospectively evaluated all adults listed between January 2000 and November 2002. Sixty-three patients (37 women, mean age 45.8 years) were listed: 48 due to chronic liver disease and 15 for a highly urgent transplantation due to acute liver failure. The main etiology of chronic disease was alcoholic (22%) or primary biliary cirrhosis (17%). Of 52 chronic patients, 26 (50%) were transplanted with a mean waiting time of 168 days. Among the others, 8 died (15%) while awaiting transplantation, 3 (5%) were removed from the list, and 15 patients still await transplantation (28%). Among acute liver failure patients, the main etiologies were autoimmune (25%) and medication induced (25%). Of 15 acute patients, 6 (37.5%) have been transplanted at a mean waiting time of 6.8 days with 100% survival posttransplantation. In this cohort, 6 patients (37.5%) died while awaiting liver transplantation, and 4 (25%) survived with medical support. In conclusion, the severity of liver disease and death rate among our waiting list was similar to that observed in developed countries. It seems reasonable to review our current allocation system based on waiting time on the list. We will have to decide whether to transplant sicker patients or those with hepatocarcinoma (as in the United States recently with the MELD system), thereby possibly decreasing the mortality rate on the waiting list at the expense of higher costs and more difficult postoperative care or to just keep our current policy.

IL-2 receptor blockers in liver transplantation: initial experience with daclizumab in Chile

Monoclonal antibodies against the interleukin 2 receptor have been developed in an effort to decrease rejection rates and spare calcineurin inhibitors when renal dysfunction occurs after transplant. While success has been reported in kidney transplantation, its effectiveness in liver transplantation is less clear.

METHODS

This prospective nonrandomized study including adult patients was performed between October 2000 and April 2003. Two groups of immunosuppressive regimens were compared: group A received 2 g of methylprednisolone intraoperatively followed by a rapid reduction with intention to withdraw by month 4, continuing on Neoral monotherapy. Cellcept was also given for 2 months in the absence or for up to 4 months in the presence of rejection. Group B received the same immunosuppressive regimen but, in addition, daclizumab 1 to 1.5 mg/kg on day 1 and day 5 posttransplant. Rejection diagnosis is made on histology basis. Protocol biopsies were performed in all the patients on day 7 and if indicated by biochemistry thereafter.

RESULTS

Both groups were similar in terms of preoperative CHILD score, serum creatinine, incidence of status I, donor and recipient age and ischemia times. The mean follow-up time was 20 months for Group B (n = 24) and 7 months for Group A (n = 10). The 1-month and 1-year rejection rates are 29.1% and 41% in Group A versus 20% and 30% in group B. Rejection severity was similar between both groups. One-year patient and graft survival rates were 96% and 92% in group A and 100% for both in Group B.

CONCLUSIONS

In this series, daclizumab induction therapy seems to display a trend toward a lower rejection rate without increasing infectious complications nor affecting graft survival rates.

Ovarian 3-hydroxy-3-methylglutaryl-CoA reductase in Blattella germanica (L.): pattern of expression and critical role in embryogenesis

In the ovary of adult Blattella germanica, the enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) is highly expressed in mid-late vitellogenesis, suggesting a functional link of the mevalonate pathway with choriogenesis. The inhibitor of HMG-CoA reductase, fluvastatin, applied in females in late vitellogenesis, inhibits the activity of the enzyme in the ovary and in the developing embryos within the ootheca. This does not affect choriogenesis or ootheca formation but reduces the number of larvae per ootheca. Our results suggest that fluvastatin is incorporated into the oocytes and has delayed inhibitory effects on the oviposited eggs. HMG-CoA reductase is essential for embryogenesis, but not for chorion formation.

[Jejunal diverticulosis: a cause of infrequent gastrointestinal hemorrhage. Case report]

Jejunal diverticulosis is a very uncommon acquired disease. Clinical manifestations include acute life threatening complication such as perforation, obstruction and bleeding. Jejunal diverticulosis is an extremely rare site of origin of gastrointestinal bleeding, with fewer than seventy cases reported in the literature. We report a 77-year-old patient with a recurrent severe gastrointestinal bleeding manifested by melena and hematochaezia. During the hospitalization the tagged red blood cell scanning was positive for bleeding in the jejunum. At laparotomy, several large-mouthed diverticula at the proximal jejunum were identified. Approximately 30 centimeters of the involved segment was resected with primary end-to-end anastomosis. Postoperative 7 month evolution has been favorable, without any evidence of rebleeding. This report reviews the literature concerning this disease, discusses some diagnostic methods of studying small bowel bleeding and highlights the need to consider this diagnosis in old patients with a gastrointestinal hemorrhage of unknown origin (Rev Méd Chile 2000; 128: 1133-38).

Selenium, zinc and copper plasma levels in intrahepatic cholestasis of pregnancy, in normal pregnancies and in healthy individuals, in Chile

BACKGROUND/AIMS

Low blood Se levels have been previously shown in normal pregnancies (third trimester) and significantly lower levels in patients with intrahepatic cholestasis of pregnancy (ICP), in Finland and in Chile, suggesting that a low or marginal dietary availability of Se may contribute to the pathogenesis of this disease. The aim of this study was to investigate whether a temporal change in plasma concentration of Se, and seasonal fluctuations in plasma concentrations of Se, Zn and Cu, could coincide with changes in the prevalence of ICP.

METHODS

A cross-sectional cohort study was done including 21 ICP patients, 98 women in the third trimester of a normal pregnancy, 29 non-pregnant women, and also 13 individuals (seven non-pregnant women and six men) who had been studied 9 years before. Plasma Se, Zn and Cu were measured by atomic spectroscopy. Plasma Se levels in the present study were compared to the results obtained 5 to 7 years before, employing identical methodology in similar population samples.

RESULTS

Plasma Se concentrations in non-pregnant women were higher than in the previous study: 1.43+/-0.34 micromol/l vs 0.85+/-0.13; p<0.001. In comparison to non-pregnant women, normal pregnancies near term had lower plasma levels of Se: 1.08+/-0.25 micromol/l; p<0.01, and Zn: 17.90+/-3.61 micromol/l vs 19.71+/-3.21; p<0.05, but higher plasma levels of Cu: 34.35+/-7.12 micromol/l vs 20.62+/-3.34; p<0.01. In normal pregnancies, plasma Se concentration was significantly higher in summer (1.34+/-0.19 micromol/l) than in the other seasons, while Zn and Cu diminished. Similar to previous studies, ICP patients had significantly lower Se plasma levels than normal pregnancies: 0.94+/-0.12 micromol/l, p<0.05, and Cu levels were significantly higher: 50.80+/-7.02 micromol/l, p<0.01. Cu plasma levels correlated with the biochemical severity of the disease. Zn did not change in ICP.

CONCLUSIONS

The present study shows that the decrease in the prevalence of ICP in Chile during the last decade coincides with an increase in plasma Se levels. Its lower incidence during summer coincides with a higher plasma Se concentration in summer than in other seasons, as observed in normal pregnancies.

Gallbladder motility and lithogenesis in obese patients during diet-induced weight loss

Obesity and weight loss are important risk factors for gallstone development. The mechanisms involved are unknown. We prospectively studied changes in gallbladder (GB) emptying and bile composition during weight loss. We studied 12 alithiasic obese subjects who entered a six-month diet program (800-1200 kcal/day, 26 g fat/day). As controls we evaluated 12 healthy nulliparous nonobese young women. GB volumes were studied by ultrasonography (fasting volume, GBFV; residual volume after a liquid meal, GBRV) at entry and after 4 and 20 weeks of dieting. Bile acid pool size, biliary lipid composition, presence of cholesterol crystals, and nucleation time were also studied. Of 12 obese subjects studied (mean BMI 35.1 kg/m2), 10 remained in the program for six months, but only six completed the entire study protocol, obtaining a significant weight loss (BMI: 31.2 kg/m2, P < 0.001). GBFV was greater in obese subjects than in nonobese controls (27.5 +/- 10.7 vs 11.7 +/- 6 ml; P < 0.05). GBRV and GB emptying curves were similar in both groups and did not change during weight loss. The obese subject who developed gallstones (1/10) was the only one who had cholesterol crystals in bile and a sluggish initial GB emptying.

IN CONCLUSION

(1) obese subjects had a greater GBFV than controls; however, the GB emptying was adequate. (2) During weight loss we did not observe significant changes in GB kinetics or the bile parameters studied. (3) We observed a relatively low frequency of gallstone formation, which can be explained by a high fat content of the diet (26 g/day) and by the adequate GB emptying of our group of patients. (4) An abnormal GB contractility and cholesterol crystals in bile could be considered premonitory to gallstone formation.

Disruption of the intestinal barrier and bacterial translocation in an experimental model of intestinal obstruction

Clinical evidence and the use of experimental models in laboratory animals indicate that the intestine is a reservoir of microorganisms that can cause systemic infection in the human. The purpose of this work was to study the possible effect of intestinal obstruction (IO) on the mechanical and chemical barriers that bring protection against microorganisms crossing from the intestinal lumen towards the systemic tissues. We demonstrated that 24 hours after IO, histological and ultrastructural alterations do occur, seriously compromising the structure of the intestinal barrier in 100% of the studied animals. Likewise, it was observed that during the same period, microorganisms translocation from intestine to the peritoneal cavity and liver (100 and 80% respectively) occurred. The lungs were spared. Changes observed in the intestinal epithelium are related to a process similar to that produced by intestinal ischemia: mitochondrial destruction, with subsequent decrease of its capacity to supply energy and to preserve the equilibrium and structure of the intestinal epithelium. We propose that translocation of enteric bacteria may be the cause of the infection that brings about the death a significant group of animals at 48 hours (27%) and 72 hours (33%) post-IO.

[Treatment of refractory ascites using a transjugular intrahepatic portosystemic shunt (TIPS). Clinical case]

Approximately, 10% of cirrhotic patients with ascites become refractory to medical treatment, a condition that reduces overall survival. TIPS is a therapeutic alternative for the management of refractory ascites. It corrects sinusoidal portal hypertension, becoming a rational and relatively safe therapeutic approach. The most frequent complications of TIPS are the development of hepatic encephalopathy and a high incidence of shunt stenosis or occlusion after one year of follow-up. We report a 43 years old alcoholic cirrhotic male with ascites refractory to medical treatment, that required multiple large volume paracentesis, whose clinical condition deteriorated progressively. A TIPS was successfully placed with a rapid and complete resolution of ascites and marked improvement of his clinical condition. During the ensuing six months the patient remained in excellent conditions, but was lost from follow-up and resumed excessive alcohol intake. Eight months after TIPS placement he had an upper gastrointestinal bleeding and died.

Epidermal growth factor (EGF)-induced up-regulation and agonist- and antagonist-induced desensitization and internalization of A1 adenosine receptors in a pituitary-derived cell line

This report concerns the study of homologous and heterologous regulation of cell surface A1 adenosine receptors (A1R) in a pituitary-derived cell line. This has been possible by the use of the recently developed anti-A1R antibodies in immunocytochemical assays. Functional desensitization and internalization of A1R in GH4 cells occurred after treatment with agonist but also with antagonist. Epidermal growth factor (EGF) treatment led to the up-regulation of cell surface A1R in GH4 cells. Confocal analysis evidenced an EGF-induced increase of A1R present in intracellular clathrin-coated vesicles. The up-regulation was blocked by actinomycin D thus suggesting the involvement of protein synthesis in the effect induced by the growth factor. These results constitute the first example of adenosine receptor regulation by EGF and one of the few examples of antagonist-induced desensitization and internalization among G-protein-coupled receptors.

[Enteral nutrition in severe ulcerative colitis. Digestive tolerance and nutritional efficiency]

BACKGROUNDS AND AIMS

Total parenteral nutrition (TPN) has been traditionally used as an adjunctive therapy in severe ulcerative colitis patients. We performed a prospective study to ascertain the safety, nutritional efficiency, tolerance and costs of total enteral nutrition in this situation.

METHODS

After 48 hours of intensive medical treatment, severe ulcerative colitis patients initiated enteral feeding with a polymeric formula. The formula concentration and volume were increased daily.

RESULTS

17 patients (7 women, 10 men; age 36.8 +/- 12.8 years) with a mean clinical activity score of 15.6 +/- 1.5 were included. In 14 patients (82.4%) enteral nutrition was well tolerated, attaining in 11 of them more than 80% of the caloric requirements by day 4. In 3 cases we observed vomiting and bloating. Prealbumin levels improved significantly from 11.1 +/- 3.4 mg/dl to 22.7 +/- 6.8 mg/dl (p = 0.002) at the end of enteral nutrition (11.8 +/- 4.7 days). Albumin and other nutritional parameters did not change.

CONCLUSIONS

Total enteral nutrition could be considered a safe and well tolerated nutritional support in these patients. Although albumin and other nutritional parameters did not change during the study period, the increase in prealbumin levels suggests a favourable anabolic effect of total enteral nutrition.

Regulation of L-type calcium channels in GH4 cells via A1 adenosine receptors

Identification of A1 adenosine receptors (A1Rs) in a tumor cell line derived from rat pituitary (GH4 cells) was performed by ligand binding and immunological experiments. Subsequently, the involvement of A1Rs in the regulation of calcium conductance was studied in these cells. The agonist N6-(R)-(2-phenylisopropyl)adenosine (R-PIA) did not modify the intracellular calcium basal levels, whereas it inhibited the increase produced by 15 mM KCl depolarization. The antagonist 1,3-dipropyl-8-cyclopentylxanthine led to the opening of voltage-dependent cell surface calcium channels in the absence of exogenous KCl. The channels were of the L type because the effect was abolished by calciseptine and by verapamil. These results suggest that endogenous adenosine exerts a tonic inhibitory effect on calcium transport. This was confirmed by the high adenosine concentration found in cell supernatants (up to 1 microM) and by the calcium mobilization produced by exogenously added adenosine deaminase. In depolarizing conditions, the calcium peak in the presence of adenosine deaminase was reduced when cells were preincubated with R-PIA, thus suggesting that A1R activation regulates the intensity of depolarization. These results demonstrate that adenosine is an important regulator of the physiological state of pituitary tumor cells by modulating, in an autocrine manner, the activity of L-type voltage-dependent calcium channels.

Modulation of GH4 cell cycle via A1 adenosine receptors

Identification and characterization of A1 adenosine receptors (A1Rs) in a tumor cell line derived from rat pituitary (GH4 cells) was performed by ligand binding and immunocytochemistry. Subsequently, the involvement of A1Rs in the regulation of cell proliferation was studied in these cells. The agonist N6-(R)-phenylisopropyladenosine (R-PIA) did not modify the number of cultured cells, but it regulated the kinetics of the cell cycle. By means of experiments of pulse and of pulse and chase with bromodeoxyuridine and further labeling with Hoechst 33258, propidium iodide, and/or fluorescein-conjugated antibodies against bromodeoxyuridine, it was demonstrated that R-PIA, via A1Rs, accelerated progression from G0/G1 to S phase and from S to G2/M phase of the cell cycle, whereas the initiation of a new cycle occurred at the same time in treated and untreated cells. As a consequence, R-PIA did not change the total length of the cycle. This is the first description of cell cycle regulation without modification of cell proliferation. Although pertussis toxin blocked the R-PIA-induced inhibition of cyclic AMP production in these cells, it did not affect the R-PIA action on the cell cycle. In contrast, cholera toxin mimicked the action of R-PIA. Thus, it is likely that regulation of the cell cycle via A1Rs is mediated by heterotrimeric G proteins different from those that mediate inhibition of adenylate cyclase. Due to the fact that cells in G0/G1 phase were less susceptible to secretory signals, adenosine, in an autocrine manner and by regulating the cell cycle kinetics, may contribute to the modulation of the secretory capacity of pituitary cells.

[Multiple hepatosplenic abscesses caused by Yersinia enterocolitica in a patient with hemochromatosis]

Yersinia enterocolitica is a gram-negative bacillus that thrives in conditions associated with iron overload. We describe an unusual case of a diabetic patient with a previously unrecognized hemochromatosis presenting with Y. enterocolitica septicemia. He was admitted because of a 10 day history of abdominal pain, fever and jaundice. Blood cultures grew Y. enterocolitica. The abdomen CT scan showed multiple liver and splenic abscesses. Antibiotic treatment with ciprofloxacin (2 months) resulted in a good clinical response. Serum iron studies showed iron overload. Liver biopsy revealed moderate fibrosis and early cirrhosis with large amounts of hemosiderin granules deposited in hepatocytes and bile duct epithelium. This report reviews the literature and highlights that iron overload must be ruled out in Yersinia septicemia patients.

[Intrasphincteric injection of botulinum toxin in patients with esophageal achalasia]

BACKGROUND

Intrasphincteric injection of botulinum toxin (BoTx) has demonstrated to be effective in the short-term treatment of achalasia.

AIM

To assess the efficacy, safety and long-term outcome of BoTx injection into the lower esophageal sphincter (LES) of patients with achalasia.

PATIENTS AND METHODS

Eight patients received 80 units of BoTx. Assessment of response was based on changes in the symptom scores (0-9) and esophageal manometric studies.

RESULTS

Six out of 8 patients (75%) had sustained clinical improvement after therapy. This effect was maintained for a mean time of 17.8 months. The symptom score decreased from a mean of 6.7 to 0.5 (p < 0.01) and after treatment, LES pressure decreased from 63 to 25.5 mm Hg (p = 0.07). There were no serious adverse effects. Five of the six responders have relapsed. Two of these patients received a second BoTx injection with satisfactory results, two went to surgery and one refused other type of therapy and died of pneumonia.

CONCLUSIONS

Intrasphincteric BoTx injection is a simple, safe and effective method of treatment in patients with achalasia, with a duration of response averaging 1.5 years. Its use may be suggested in some patients with high surgical risk and those who refuse a more invasive therapy. It is also useful in malnourished patients to attain an adequate nutritional status before surgery.

Effect of prenatal T4 treatment in neonatal morbidity: preliminary findings

We report our experience with the use of intra-amniotic thyroxine to accelerate fetal maturation in preterm delivered infants. One hundred and fourteen infants who had received 500 micrograms of thyroxine weekly prenatally until an L/S ratio greater or equal to 2.0 was achieved, were compared to 113 premature infants who had not been given thyroxine or steroids prenatally. After stratification by weight, the relative incidence of respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), necrotizing enterocolitis (NEC) and intraventricular hemorrhage (IVH) were compared. A decrease in the incidence of RDS was observed in the infants with birth weight between 1000 and 1500 g who had received more than one dose of intra-amniotic thyroxine. No difference in the incidence of RDS was observed in infants with birth weight of less than 1000 g or over 1500 g. One dose of thyroxine had no effect in decreasing the incidence of RDS, PDA, NEC, and IVH in any of the groups. We conclude intra-amniotic thyroxine seems to decreases the incidence of RDS in very low birth weight infants.

[Portal vein thrombosis associated with essential thrombocytosis. Clinical cases and review of the literature]

Lately, myeloprolipherative disorders are frequently reported as causes of portal vein thrombosis, probably due to the early detection of latent cases of this condition. We report two patients with portal vein thrombosis that presented with abdominal pain, nausea, vomiting and clinical consequences of portal hypertension such as variceal hemorrhage, splenomegaly and ascites. Diagnosis was made by a CAT scan in one patient and doppler ultrasound in the other. Both patients had high platelet counts and an essential thrombocytosis in the bone marrow.

Risk and consequence of infection at the site of microsurgical repair: an experimental model

The consequences of postoperative infection at the site of microsurgical repair were studied. The experiment used 60 Wistar rats which were divided into 3 groups of 20 each. The femoral artery, vein, and nerve were transected unilaterally and repaired using microsurgical techniques. Staphylococcus aureus was then inoculated into the wound of group 1. Beta-hemolytic Streptococcus was inoculated into the wound of group 2. Group 3 rats served as controls. Clinical, anatomical, bacteriological and histopathological examinations were performed on postoperative days 8 and 30. Wounds in which S. aureus was inoculated demonstrated a significant tendency toward vascular thrombosis with extensive tissue destruction. In the majority of these cases, the necrosis caused by the primary infection engendered an associated, opportunistic infection. Streptococcal inoculations in group 2 demonstrated less severe changes than in group 1. These changes were characterized by injury of the vascular structures themselves with a significant tendency for thickening of the arterial wall, perivascular inflammation, and hematoma formation at the site of the repair. This model allows demonstration of the enzymatic and toxic consequences of bacterial infection in a postoperative site characterized by cellular destruction and interstitial edema surrounding foreign bodies represented by sutures.