Rechallenge in idiosyncratic drug-induced liver injury: An analysis of cases in two large prospective registries according to existing definitions

INTRODUCTION

Data on positive rechallenge in idiosyncratic drug-induced liver injury (DILI) are scarce. We aim to analyse the clinical presentation, outcome and drugs associated with positive rechallenge in two DILI registries.

METHODS

Cases from the Spanish and Latin American DILI registries were included. Demographics, clinical characteristics and outcome of cases with positive rechallenge according to CIOMS/RUCAM and current definitions were analysed.

RESULTS

Of 1418 patients with idiosyncratic DILI, 58 cases had positive rechallenge (4.1%). Patients with positive rechallenge had shorter duration of therapy (p=0.001) and latency (p=0.003). In patients with rechallenge, aspartate transaminase levels were increased (p=0.026) and showed a prolonged time to recovery (p=0.020), albeit no differences were seen in terms of fatal outcomes. The main drug implicated in rechallenge was amoxicillin-clavulanate (17%). The majority of re-exposure events were unintentional (71%). Using both existing definitions of positive rechallenge, there were four cases which exclusively fulfilled the current criteria and five which only meet the historical definition. All cases of positive rechallenge, irrespective of the pattern of damage, fulfilled the criteria of either alanine transaminase (ALT) ≥3 times the upper limit of normal (ULN) and/or alkaline phosphatase (ALP) ≥2 times ULN.

CONCLUSIONS

Episodes of rechallenge were characterised by shorter duration of therapy and latency, and longer time to resolution, but did not show an increased incidence of fatal outcome. Based on our findings, ALT ≥3 times ULN and/or ALP ≥2 times ULN, regardless of the pattern of damage, is proposed as a new definition of rechallenge in DILI.

Liver injury due to COVID-19 in critically ill adult patients. A retrospective study

INTRODUCTION AND AIM

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing the current pandemic of acute respiratory disease known as COVID-19. Liver injury due to COVID-19 is defined as any liver injury occurring during the course of the disease and treatment of patients with COVID-19, with or without liver disease. The incidence of elevated liver transaminases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), ranges from 2.5 to 76.3%. The aim of the present study was to describe the hepatic biochemical abnormalities, after a SARS-CoV-2-positive polymerase chain reaction (PCR) test, and the mortality rate in critically ill patients.

MATERIALS AND METHODS

A retrospective study was conducted that included 70 patients seen at a private hospital in Mexico City, within the time frame of February-December 2021. Median patient age was 44.5 years (range: 37-57.2) and 43 (61.4%) of the patients were men. Liver function tests were performed on the patients at hospital admission.

RESULTS

Gamma glutamyl transferase (GGT) levels were elevated (p = 0.032), as were those of AST (p = 0.011) and ALT (p = 0.021). The patients were stratified into age groups: 18-35, 36-50, and > 50 years of age. The 18 to 35-year-olds had the highest liver enzyme levels and transaminase levels were higher, the younger the patient. Due to the low mortality rate (one patient whose death did not coincide with a hepatic cause), the multivariate analysis showed an R2 association of 0.689, explained by AST, GGT, and C-reactive protein levels.

CONCLUSIONS

Despite the increase in transaminases in our study population during the course of COVID-19, there was no increase in mortality. Nevertheless, hospitalized patient progression should be continuously followed.

[Liver injury due to COVID-19 in critically ill adult patients. A retrospective study]

INTRODUCTION AND AIM

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing the current pandemic of acute respiratory disease known as COVID-19. Liver injury due to COVID-19 is defined as any liver injury occurring during the course of the disease and treatment of patients with COVID-19, with or without liver disease. The incidence of elevated liver transaminases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), ranges from 2.5 to 76.3%. The aim of the present study was to describe the hepatic biochemical abnormalities, after a SARS-CoV-2-positive polymerase chain reaction (PCR) test, and the mortality rate in critically ill patients.

MATERIALS AND METHODS

A retrospective study was conducted that included 70 patients seen at a private hospital in Mexico City, within the time frame of February-December 2021. Median patient age was 44.5 years (range: 37-57.2) and 43 (61.4%) of the patients were men. Liver function tests were performed on the patients at hospital admission.

RESULTS

Gamma glutamyl transferase (GGT) levels were elevated (p = 0.032), as were those of AST (p = 0.011) and ALT (p = 0.021). The patients were stratified into age groups: 18-35, 36-50, and > 50 years of age. The 18 to 35-year-olds had the highest liver enzyme levels and transaminase levels were higher, the younger the patient. Due to the low mortality rate (one patient whose death did not coincide with a hepatic cause), the multivariate analysis showed an R2 association of 0.689, explained by AST, GGT, and C-reactive protein levels.

CONCLUSIONS

Despite the increase in transaminases in our study population during the course of COVID-19, there was no increase in mortality. Nevertheless, hospitalized patient progression should be continuously followed.

The flashfm approach for fine-mapping multiple quantitative traits

Joint fine-mapping that leverages information between quantitative traits could improve accuracy and resolution over single-trait fine-mapping. Using summary statistics, flashfm (flexible and shared information fine-mapping) fine-maps signals for multiple traits, allowing for missing trait measurements and use of related individuals. In a Bayesian framework, prior model probabilities are formulated to favour model combinations that share causal variants to capitalise on information between traits. Simulation studies demonstrate that both approaches produce broadly equivalent results when traits have no shared causal variants. When traits share at least one causal variant, flashfm reduces the number of potential causal variants by 30% compared with single-trait fine-mapping. In a Ugandan cohort with 33 cardiometabolic traits, flashfm gave a 20% reduction in the total number of potential causal variants from single-trait fine-mapping. Here we show flashfm is computationally efficient and can easily be deployed across publicly available summary statistics for signals in up to six traits.

Oocyte holding in the Iberian red deer (Cervus elaphus hispanicus): Effect of initial oocyte quality and epidermal growth factor addition on in vitro maturation

Current in vitro embryo production protocols in the Iberian red deer (Cervus elaphus hispanicus) need to be optimized; oocyte harvesting in situ followed by overnight holding could reduce the human effort and shipping costs. In our work, post-mortem ovaries were retrieved, and the oocytes were harvested and allocated to G1 group (good quality) or G2 + G3 group (low quality). The oocytes were separately subjected to immediate in vitro maturation (IVM) or held overnight in a holding medium composed of 40% of TCM 199 with Earle's salts, 40% TCM 199 with Hanks' salts and 20% fetal bovine serum (FBS), at room temperature (16 hr). In vitro maturation was carried out in a basal medium supplemented or not with 50 ng/ml of epidermal growth factor (EGF). Our data showed that addition of EGF to the maturation medium increases the percentage of G1 oocytes reaching metaphase II (3.9% vs. 50%, basal vs. EGF; p < .001) and decreased their degeneration rate (69.9% vs. 22.2%, basal vs. EGF; p < .01) when oocytes were immediately matured. Overnight holding increased the meiotic competence of G1 oocytes (37.5% matured in basal medium) and EGF increased prophase arrest in G2 + G3 oocytes (16.1% vs. 38.8% in germinal vesicle [GV] stage in basal medium vs. EGF added medium; p < .05). Our data demonstrate that oocyte holding can be used in Iberian red deer oocytes. Interestingly, EGF addition increases the oocytes' meiotic competence in immediately matured oocytes but not after oocyte holding depending upon initial oocyte quality.

Association of polymorphisms in growth hormone and leptin candidate genes with live weight traits of Brahman cattle

Polymorphisms in candidate genes can produce significant and favorable changes in the phenotype, and therefore are useful for the identification of the best combination of favorable variants for marker-assisted selection. In the present study, an assessment to evaluate the effect of 11 single nucleotide polymorphisms (SNPs) in candidate genes on live weight traits of registered Brahman cattle was performed. Data from purebred bulls were used in this assessment. The dataset included birth (BW), weaning (WW), and yearling (YW) weights. A panel of 11 SNP markers, selected by their formerly reported or apparent direct and indirect association with live weight traits, was included in an assessment previously confirming their minimum allele frequency (<0.05). Live weights were adjusted BW (aBW), WW (aWW), and YW (aYW) using a generalized linear model, which included the fixed effects of herd and season of birth and the random effect of the sire and year of birth. An SNP in a growth hormone gene (GH4.1) was significantly related to aWW (P = 0.035) with an estimate substitution effect of 3.97 kg (P = 0.0210). In addition, a leptin SNP (LEPg.978) was significantly associated with aYW (P = 0.003) with an estimate substitution effect of 9.57 kg (P = 0.0007). The results suggest that markers GH4.1 and LEPg.978 can be considered as candidate loci for assisted genetic improvement programs in Mexican Brahman cattle.

[From fear of obesity to the obsesion with thinness; attitudes and diet]

OBJECTIVE

Investigate the relationship between body satisfaction, attitudes toward body and obesity, diet quality and emotional health in a group of university students. The initial hypothesis was that attitudes to thinness and fear of obesity induces weight control behaviours and lower diet quality.

METHODS

55 women of 19-25 years. The relationship between body mass index (BMI), diet quality (DQ), restrictive behaviours, eating attitudes (EDI-2, CIMEC) and attitudes toward obesity (AFA) was analyzed. Measures of health (SF-12) and emotional state (PNA) were also collected.

RESULTS

10.9% of the sample had a diet classified as "poor", 83.6% "needs improvement" and 5.5% followed a "good" diet. Most of participants were dissatisfied with their weight even when their BMI was located in the normal range. Weight-restrictive behaviors were associated with risk attitudes to eating disorders, but DQ did not discriminate among high and low BMI groups, nor was related to attitudes. The more was the anxiety (negative affect), the more were the body dissatisfaction and pressures on body image. Idealized social image of thinness was linked to the stigmatization of obesity, lower dietary diversity and more restrictive practices.

CONCLUSION

The results of this pilot study contributes to clarify the relationship between psychological and behavioral indices related to diet in university women students.

Sulfasalazine-induced linear immunoglobulin A bullous dermatosis with DRESS

Linear immunoglobulin (Ig) A dermatosis is an immune-mediated bullous disease characterized by linear deposits of IgA along the basal membrane. While usually idiopathic, it can occasionally be induced by drug exposure. We report the case of a 60-year-old woman with rheumatoid arthritis being treated with sulfasalazine who developed linear IgA dermatosis and drug rash with eosinophilia and systemic symptoms (DRESS). The dermatosis and associated symptoms resolved following withdrawal of the drug and treatment with systemic corticosteroids for 2 months. This is the first report of sulfasalazine-induced linear IgA dermatosis in association with DRESS and we believe that sulfasalazine should be added to the list of drugs that can cause linear IgA dermatosis.

Safety of specific immunotherapy using a depigmented and polymerised extract of Dermatophagoides pteronyssinus in children under five years of age

BACKGROUND

Different opinion documents point to a patient age of under five years as a relative contraindication to specific immunotherapy, arguing that this age group has a greater risk of developing anaphylaxis, and that specially trained personnel are needed to deal with the problem if it occurs. However, insufficient evidence exists to support such an affirmation.

PATIENTS AND METHODS

A retrospective follow-up observational study was made of patients aged 60 months or younger who had been subjected to specific immunotherapy. We included 77 children with a diagnosis of extrinsic bronchial asthma (n=68), extrinsic spasmodic cough (n=5) and allergic rhinitis (n=4) confirmed by clinical criteria and prick-test, with specific IgE positivity to Dermatophagoides pteronyssinus. All patients received specific immunotherapy with an extract of depigmented D. pteronyssinus polymerised with glutaraldehyde, involving an initial cluster protocol of two weeks and monthly maintenance doses. All observed adverse reactions were recorded, and classified according to European Academy of Allergy and Clinical Immunology (EAACI) criteria.

RESULTS

A total of 1837 doses were administered to the 77 patients, with four adverse reactions being observed in three patients. Three reactions (0.16% of the administered doses) were local and immediate, while one was systemic and of grade 2 (0.05% of the administered doses) - consisting of an episode of nocturnal wheezing.

CONCLUSIONS

Specific immunotherapy in children under five years of age with the extract used is safe. We consider that further studies are needed, involving other types of extracts, to allow reconsideration of the relative contraindication of patient age for the administration of immunotherapy.

Success of medical therapy in a rare case of cecal ameboma

Colitis caused by Entamoeba histolytica (EH) is prevalent in developing countries. Clinical presentation ranges from mild diarrhoea episodes to dysentery and liver abscess. Ameboma, a complication caused by EH invasion of the intestinal wall, is a rare presentation of amebiasis, occurring approximately in 1.5% of cases. Because of its insidious and variable clinical presentation only few cases are diagnosed previous to surgical intervention. We report a 52 years old Mexican-mestizo female, presenting with a pain-less right lower quadrant abdominal mass and diagnosed of cecal ameboma prior to surgery by colonoscopy and histopathologic examination. The present case highlights the importance of early diagnosis and medical therapy with antiparasitic drugs in order to avoid complications that could lead these patients to unnecessary surgical management.

Genotoxic and cytotoxic studies of beta-sitosterol and pteropodine in mouse

Beta-sitosterol (BS) and pteropodine (PT) are constituents of various plants with pharmacological activities potentially useful to man. The chemicals themselves possess biomedical properties related to the modulation of the immune and the nervous systems, as well as to the inflammatory process. Therefore, safety evaluation of the compounds is necessary in regard to their probable beneficial use in human health. The present study evaluates their genotoxic and cytotoxic potential by determining the capacity of the compounds to induce sister chromatid exchanges (SCE), or to alter cellular proliferation kinetics (CPK) and the mitotic index (MI) in mouse bone marrow cells. Besides, it also determines their capacity to increase the rate of micronucleated polychromatic erythrocytes (MNPE) in peripheral mouse blood, and the relationship polychromatic erythrocytes/normochromatic erythrocytes (PE/NE) as an index of cytotoxicity. For the first assay, four doses of each compound were tested: 200, 400, 600, and 1000 mg/kg in case of BS, and 100, 200, 300, and 600 mg/kg for PT. The results in regard to both agents showed no SCE increase induced by any of the tested doses, as well as no alteration in the CPK, or in the MI. With respect to the second assay, the results obtained with the two agents were also negative for both the MNPE and the PE/NE index along the daily evaluation made for four days. In the present study, the highest tested dose corresponded to 80% of the LD₅₀ obtained for BS and to 78% in the case of PT. The results obtained establish that the studied agents have neither genotoxic nor cytotoxic effect on the model used, and therefore they encourage studies on their pharmacological properties.

Molecular heterogeneity in chronic lymphocytic leukemia is dependent on BCR signaling: clinical correlation

Chronic lymphocytic leukemia (CLL), the most frequent form of adult leukemia in Western countries, is characterized by a highly variable clinical course. Expression profiling of a series of 160 CLL patients allowed interrogating the genes presumably playing a role in pathogenesis, relating the expression of functionally relevant signatures with the time to treatment. First, we identified genes relevant to the biology and prognosis of CLL to build a CLL disease-specific oligonucleotide microarray. Second, we hybridized a training series on the CLL-specific chip, generating a biology-based predictive model. Finally, this model was validated in a new CLL series. Clinical variability in CLL is related with the expression of two gene clusters, associated with B-cell receptor (BCR) signaling and mitogen-activated protein kinase (MAPK) activation, including nuclear factor-kappaB1 (NF-kappaB1). The expression of these clusters identifies three risk-score groups with treatment-free survival probabilities at 5 years of 83, 50 and 17%. This molecular predictor can be applied to early clinical stages of CLL. This signature is related to immunoglobulin variable region somatic hypermutation and surrogate markers. There is a molecular heterogeneity in CLL, dependent on the expression of genes defining BCR and MAPK/NF-kappaB clusters, which can be used to predict time to treatment in early clinical stages.

Skeletal muscle inflammation and nitric oxide in patients with COPD

In chronic obstructive pulmonary disease (COPD) the presence of systemic inflammation has been associated with peripheral muscle abnormalities and weight loss. To study whether inflammatory factors are important in these processes, the present study compared the skeletal muscle levels of nitrite, nitrate, nitrotyrosine, neuronal, endothelial and inducible nitric oxide synthases (nNOS, eNOS, and iNOS, respectively), and inflammatory markers (tumour necrosis factor (TNF)-alpha, CD154 and CD163) in 15 patients (forced expiratory volume in one second 43+/-11%) and 14 controls. All these markers were also compared between patients with normal and low body weight. Nitrite (12.5+/-2.6 versus 17.0+/-3.4 micromol.mg(-1) protein), nitrate (20.7+/-2.4 versus 24.4+/-4.5 micromol.mg(-1) protein) and eNOS (31.9+/-4.6 versus 43.6+/-7.5 ng.mg(-1) protein) were lower in COPD patients than in controls. Nitrotyrosine (25.6+/-5.4 versus 6.6+/-3.3 ng.mg(-1) protein), iNOS expression (32+/-9.5 versus 7.16+/-2.7 ng.mg(-1) protein), TNF-alpha (257+/-160 versus 48.3+/-4.4 pg.mg(-1) protein) and CD163 (6.4+/-2.1 versus 0.8+/-0.4 ng.mg(-1) protein) were higher in COPD patients than in controls. CD154 levels were 15.7+/-7.0 ng.mg(-1) protein in COPD patients and undetectable in controls. Similar levels of all these markers were observed in COPD patients with normal and low body weight. In conclusion, these findings suggest the presence of an inflammatory process in the muscle tissue of chronic obstructive pulmonary disease patients, and argue in favour of its participation in the pathogenesis of skeletal muscle abnormalities.

Changes in Exercise Tolerance, Health Related Quality of Life, and Peripheral Muscle Characteristics of Chronic Obstructive Pulmonary Disease Patients After 6 Weeks' Training

OBJECTIVE

This study was designed to assess changes in skeletal muscle characteristics after 6 weeks' high-intensity physical training of patients with moderate to severe chronic obstructive pulmonary disease (COPD) and to determine how the changes were related to improvements in exercise tolerance and health related quality of life (HRQL).

PATIENTS AND METHODS

Ten patients with a mean (SD) age of 60 (10) years and a forced expiratory volume in 1 second of 32% (9%) were enrolled. The effect of training on the 6-minute walk test, HRQL questionnaires, and skeletal muscles was examined for the 8 patients who completed the program. The structural and chemical characteristics of skeletal muscles before and after training were studied in vastus lateralis muscle biopsies.

RESULTS

Training significantly modified the 6-minute walk test (P<.01), HRQL (P<.05), and citrate synthetase activity (P<.05). Changes in distances walked during the 6-minute walk test were significantly related to changes in the mean area of fibers (r=0.81).

CONCLUSIONS

The results of this study indicate that 6 weeks of high-intensity physical training of COPD patients produces moderate changes in skeletal muscles which could partly explain improvements observed in exercise tolerance after respiratory rehabilitation.

Inflammation and nitric oxide production in skeletal muscle of type 2 diabetic patients

An inflammatory process may be involved in nitric oxide production in skeletal muscle of type 2 diabetic patients. Nitric oxide generation in skeletal muscle was assessed in 14 non-complicated type 2 diabetic patients and in 12 healthy subjects. In samples of quadriceps femoris muscle, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), nitrite, nitrate and nitrotyrosine were determined. The macrophage-specific antigen CD163, the T-cell membrane factor CD154 and tumour necrosis factor-alpha (TNF-alpha) were also assayed. In six patients, ultrastructural analysis of muscle was performed. Nitrites and nitrates were increased in patients as compared to controls (22.7+/-4.5 and 32.7+/-7.0 vs 16.0+/-2.9 and 22.8+/-4.0 micromol/mg protein; P<0.001, Mann-Whitney U test). Endothelial NOS was similar in diabetic and control subjects (36.4+/-13.8 vs 36.3+/-6.8 ng/mg protein), contrasting with the significant increase of iNOS recorded in patients (34.3+/-13.0 vs 8.5+/-2.8 ng/mg protein, P<0.00002). Nitrotyrosine levels were higher in the patient than in the control group (42.1+/-24.4 vs 10.3+/-2.5 ng/mg protein, P<0.00002), as were CD163 (10-fold) and TNF-alpha (fourfold) levels. Furthermore, CD154 levels were detectable only in the patient samples (10.2+/-5.3 ng/mg protein). By multiple-regression analysis, changes in glycated haemoglobin values could predict 96% variation in nitrotyrosine. Macrophages were present in all muscle samples analysed by electromicroscopy. The increased levels of CD163, CD154 and TNF-alpha indicate that an inflammatory process occurs in skeletal muscle of type 2 diabetic patients. This may contribute to iNOS induction, muscle damage and insulin resistance.

Glutathione and glutamate levels in the diaphragm of patients with chronic obstructive pulmonary disease

Recently, decreased glutamate (Glu) and reduced glutathione (GSH) levels were reported in the quadriceps femoris of patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate whether Glu and GSH levels are also modified in the diaphragm of these patients. Nine male COPD patients (forced expiratory volume in one second (FEV1) range 28-68% of the predicted value) and seven male patients with normal pulmonary function (mean +/- SD FEV1 86 +/- 3% pred) submitted to thoracotomy were included. Biopsy specimens were taken from the diaphragm (both groups) and the quadriceps femoris (COPD group alone) in order to assess fibre size, myosin heavy chain expression, GSH levels and amino acid profile. The COPD group was characterised by preserved fibre size, a higher proportion of type I fibres (mean +/- SEM 70 +/- 3 versus 26 +/- 4%), and higher Glu and GSH content in the diaphragm compared to the quadriceps muscle. However, Glu and GSH levels were similar in diaphragm from the COPD and control groups. Glu level correlated with GSH level in both muscles. No significant correlation was found between Glu or GSH level and fibre size or proportions. This study shows that glutamate and reduced glutathione levels are preserved in the diaphragm of chronic obstructive pulmonary disease patients. Alterations in glutamate and reduced glutathione metabolism are muscle-specific in chronic obstructive pulmonary disease, affecting the quadriceps femoris but not the diaphragm. Glutamate and reduced glutathione levels are strongly interrelated in both muscles, independent of fibre type distribution and fibre size.

Development and validation of an enzyme-linked immunosorbent assay (ELISA) for recombinant human gamma interferon

A one-site ELISA for the quantification of recombinant human gamma interferon (rh-IFN-gamma) was developed and validated. A single monoclonal antibody (Mab) was used as a "catching" antibody and as a horseradish peroxidase (HRP)-labeled conjugate. Detection limit and quantification limit of this assay were estimated to be 1.26 and 15 ng/mL, respectively, and the coefficient of variation was below 15%. The ELISA was specific for rh-IFN-gamma, showing no cross reactivity to other related molecules in the range of the concentrations studied. The results correlated well with those obtained by a bioassay method. By using this assay, it was demonstrated that 0.01-1% (v/v) Tween 80 protected rh-IFN-gamma during freezing and thawing.

Metabolic changes in DOCA-salt hypertensive rats

In a previous report, we observed an altered proportion of fiber types and a reduction of capillary per fiber ratio in extensor digitorus longus (EDL) and soleus (SOL) muscles of deoxicorticosterone acetate (DOCA)-salt hypertensive rats when compared with controls. The aim of the present study was to ascertain various carbohydrate and lipid enzyme activities and substrates that may be involved in the morphological changes reported. In the SOL muscle of hypertensive rats, glucose, glycogen and triglycerides (TG) levels were increased, citrate synthase (CS) and beta-hydroxy-acyl-CoA dehydrogenase (HAD) activities were reduced, while hexokinase (HK) and lipoprotein lipase (LPL), LPL mass, lactate and free fatty acids (FFA) levels were unchanged. In EDL muscles of hypertensive rats, glycogen levels and LPL mass were higher than in controls, while CS, HAD, HK, and LPL activities and glucose, lactate, FFA and TG levels were unmodified. Serum levels of insulin, TG, cholesterol and FFA were increased while glucose levels were decreased and high-density lipoprotein-cholesterol levels were similar in hypertensive rats when compared with controls. In conclusion, hypertensive rats showed increased glycogen in both EDL and SOL muscles, with hyperinsulinemia and reduced glycemia. Hyperinsulinemia might have been a compensatory response to insulin resistance. The oxidative capacity of SOL muscle was reduced indicating that glucose uptake was conduced via non-oxidative metabolism. TG, FFA and cholesterol were increased in serum and TG in SOL muscle.

[Basic structure of respiratory and peripheral muscles in the beagle dog]

BACKGROUND

The dog is one of the most widely used animals in studies of respiratory physiopathology, mainly because of its physiological characteristics. However, ethical and legal constraints are placed on the use of some species in our context.

OBJECTIVE

We studied the underlying structural features of respiratory and peripheral muscles in the beagle dog in order to suggest reference values for future studies.

METHOD

Fourteen young beagles were selected. Samples were taken from the costal diaphragm (DFG), external intercostal (EI) and vastus medialis (VM) muscles. We analyzed fiber percentages and sizes (immunohistochemistry, using myosin heavy chain [MyHC (monoclonal antibodies), percentages and absolute number of MyHC isoforms (electrophoresis and ELISA), and level of membrane damage (immunohistochemistry, using anti-fibronectin monoclonal antibodies).

RESULTS

In the EI muscle, type I fibers were larger (by 20%) than type II fibers. Fibers resistant to fatigue (type I) predominated greatly over fast contraction fibers (type II) in all three muscles analyzed (DFG 57% 11% vs. 45% 12%; EI 58% 5% vs. 43% 5%; and VM 70% 8% vs. 34% 7 %). Few hybrid fibers (co-expression of fast and slow MyHC) were found and their percentages were similar in all three muscles. The absolute expression of MyHC was greater in the VM than in the respiratory muscles, with a relative predominance of the MyHC I isoform in the DFG and VM muscles and a similar tendency in the EI muscle. Membrane damage was very slight in all three muscles.

CONCLUSIONS

The phenotype characteristics of respiratory and peripheral muscles in the beagle correspond to what we would expect functionally for a breed initially selected for hunting, with minimal lesions under normal circumstances, a predominance of fibers and proteins that are resistant to fatigue, and larger fibers in the EI, a muscle that plays a role in respiration in dogs.

Muscle fiber composition and capillarization in relation to metabolic alterations in hypertensive men

The aim of this study was to determine if there is a relationship among skeletal muscle fiber composition, capillarization, blood pressure (BP) and/or the components of the metabolic syndrome. Two groups were compared: 8 recently diagnosed, untreated, hypertensive men (BP > or = 140/90) and 7 normotensive men as controls. Muscle biopsies were taken from the vastus lateralis part of quadriceps femoris muscle in order to assess: fiber type proportion, capillarization, hexokinase, citrate synthase, beta-hydroxyacyl CoA dehydrogenase activities; lipoprotein lipase mass and activity, free fatty acids and triglycerides. Serum levels of insulin, glucose, cholesterol, uric acid and triglycerides were also assayed. Hypertensive patients had higher insulin levels and insulin resistance [homeostasis model assessment (HOMA)], a decreased hexokinase activity and an increase of muscle lipoprotein lipase mass as compared to controls. Interestingly, correlations among values differ in each group. The percentage of type IIB fibers was related to diastolic BP (blood pressure) in control and to mean BP in hypertensive subjects. Serum cholesterol and glucose were inversely related to the percentage of type I fibers in the control subjects. Negative correlations between capillarization and glucose, cholesterol and uric acid levels were found in control subjects. In all subjects, a strong correlation was found between SBP (systolic BP) and DBP (diastolic BP), and insulin resistance (IR) and uric acid levels. Muscle fiber type proportion and capillarization were related to blood pressure and components of the metabolic syndrome.

Antinociception induced by PAG-microinjected dipyrone (metamizol) in rats: involvement of spinal endogenous opioids

Dipyrone microinjection into the periaqueductal gray matter (PAG) elicits antinociception in rats by activating endogenous opioidergic circuits in PAG and the rostral ventromedial medulla. We have now found that endogenous opioids in the spinal cord are also involved. Responses of dorsal spinal neurons to noxious stimulation of a hindpaw were diminished (to 38-44%) by dipyrone microinjection (100 microg/0.5 microl) into the PAG. This was abolished by application of naloxone (50 microg/50 microl) to the spinal cord. The fact that dipyrone, a non-opioid analgesic, activates opioidergic circuits may be clinically important.

Capillary changes in skeletal muscle of patients with essential hypertension

Arterial hypertension produces changes along the vascular tree. However, there are few reports on its effect on human muscle capillaries. This study demonstrates the effects of essential hypertension on the capillaries of human quadriceps muscle. Muscle biopsy was taken from quadriceps femoris in eight men with recent diagnosis of essential hypertension, without treatment. Biopsies were also taken from eight normotensive men and were used as controls. Fiber types were classified by ATPase reaction, capillaries counted in alpha-amylase-PAS stained sections and ultrastructure studied by conventional methods of transmission electron microscopy. No changes were found in capillaries or muscle fiber types by histochemical methods. However, electron microscopy revealed abnormal capillaries with endothelial cells infoldings into the lumen, as well as occluded or degenerated capillaries. In some cases the endothelial cell area covered by pericytes was increased. Basement membrane of capillaries was frequently increased in width, sometimes irregularly, and in other instances it was reduplicated. In transversely sectioned capillaries lumen diameter was reduced and wall thickness was increased, although total diameter was unchanged. In hypertensive patients the finding of some degenerated capillaries adjacent to muscle fibers could be interpreted as the beginning of a process of rarefaction. Some capillaries showed morphological changes, and the ratio wall thickness/lumen was increased.

Malignant rhabdoid tumor beside benign skin mesenchymal neoplasm with myofibromatous features

Only a few reports of primary cutaneous rhabdoid tumors have been published. We describe the case of a 3-month-old female patient who developed a rhabdoid type cutaneous sarcomatoid neoplasm in her upper back, close to a benign myofibromatous proliferation of infancy. The lesion was studied both by light microscopy and immunohistochemically. Flow cytometry was performed showing a DNA diploid profile of the malignant tumor. The pathological findings suggest a mesenchymal origin (hemangiopericytic or myofibroblastic type) for both tumors. The patient was surgically treated, but she died nine months later.

[Effectiveness educational programs for school dental health. Experimental trial]

This paper is a limited-scope experimental study to evaluate the effectiveness of the Dental Health Educational Programs implemented in Venezuelan schools by the Dentistry Division of the Ministry of Health and Social Welfare. Two hundred and ninety-six six-to-twelve year olds were randomly selected from two schools, one private, the other public, located in the Municipality of Maracaibo, State of Zulia, Venezuela. The children assigned to each school were randomly distributed among the experimental and control groups. A general hypothesis was set up, stating that reinforcement and motivation generate changes in the gingival health of the children under study, but with different results for each, depending on their psycho-social characteristics. Two approaches were used: instruction/supervision and instruction/supervision/reinforcement/stimulation. These two approaches were then measured against a "psycho-social profile" which is based on material conditions and the developmental stages of the children. Instructions were given to the experimental group on how to brush their teeth. They were supervised, reinforced and stimulated for a period of six months, with a post-test assessment. The control group was only given instructions on how to brush their teeth and supervised. A scale based on Massler's classification was used to determine the developmental stages. Standardized indices were used to evaluate the dependent variable: Plaque Index and Gingival Index. The results showed that: the material living conditions and developmental stage of the child are elements that influence the assimilation of pre-established behavior, the basis of preventive programs.

[Cardiac failure secondary to hypoparathyroidism. An unusual presentation]

The case of a 37 year old woman with hypoparathyroid congestive heart failure (CHF) is reported. Thyroidectomy had been performed eight years earlier and she had experienced symptoms of hypocalcemia postoperatively. CHF improved rapidly and completely with the treatment of hypocalcemia. Good prognosis is emphasized but it is necessary to think about this cause of ventricular dysfunction in a patient with CHF and a history of neck surgery in order to make an early diagnosis. Pathogenic mechanisms and differential diagnosis are discussed.

Temporary and permanent restorations for fractured permanent teeth with immature apices: a clinical study

Clinical and radiological studies of the fractured teeth of patients between seven and eleven years old were conducted to assess the use of permanent and immediate (emergency) techniques for reconstructing anterior permanent teeth with immature apices. The general hypothesis states that, given the physical and biocompatible properties of the materials used in the immediate (emergency) technique, there are no significant differences between the two techniques as far as pulp vitality and apical growth are concerned. A sample of fifty-six patients was selected. They had Class I, II or III fractures, for which permanent and immediate (emergency) techniques were used in equal numbers. Thermal, mechanical, and electrical tests were used to evaluate pulp vitality compared with the homologous tooth. Apical convergence was the radiological criterion used for determining the end of the radicular process. After one year, both techniques allow preservation of pulp vitality. Results show that, unlike the conventional technique (permanent), radicular formation was completed first in teeth reconstructed using the immediate (emergency) technique. Statistical analysis shows no definitive relationship between the technique used and completion of apical growth time (P > 0.05). In conclusion, comparison between the mediate (permanent) and immediate (emergency) techniques shows that the immediate (emergency) technique is an adequate alternative for reconstructing fractured teeth, because of the greater esthetic and functional advantages at the patient's disposal.

Inactivity changed fiber type proportion and capillary supply in cat muscle

The effect of different levels of activity on fiber types, capillaries and enzymes of gastrocnemius and soleus muscles was studied in two groups of cats. The first group was successfully kept in a large room, exercised on a treadmill 15 min daily 5 days per week and kept in individual small cages. Each period lasted 6 weeks. A muscle biopsy was taken after each period. The second group was formed by cats that were caged for over 20 months. In the group caged for over 20 months, gastrocnemius muscle showed higher IIB and lower I fiber type proportion. Fiber cross-sectional area was not different in any condition. All capillary measurements were significantly lower in gastrocnemius muscle of long-term caged cats, and capillaries per mm2 were lower in soleus muscle of these cats. Exercise increased capillary/fiber in soleus muscle but subsequent caging did not reduced it. In soleus muscle, beta-hydroxy-acyl-CoA dehydrogenase levels decreased after the cage period and hexokinase levels increased after the exercise and decreased after the cage period. In conclusion, different levels of activity for short time produced enzyme changes in soleus muscle, whereas long-term inactivity changed fiber type proportion in gastrocnemius muscle and reduced capillary supply.

Capillary and muscle fiber type changes in DOCA-salt hypertensive rats

BACKGROUND

Discrepancies concerning the effect of hypertension on capillaries and muscle fiber types in skeletal muscle have been reported. This study demonstrates the effects of hypertension produced by deoxicorticosterone acetate (DOCA) and salt load on the extensor digitorum longus (EDL) and soleus muscles of the rat.

METHODS

Hypertension was produced by subcutaneous injections of DOCA and supplemented with drinking 1% NaCl solution. One group was treated for 7 weeks and another for 14 weeks. Fiber types were classified by ATPase reaction at pH 4.35, capillaries were counted in alpha-amylase-PAS-stained sections, and ultrastructure was studied by conventional methods of transmission electron microscopy.

RESULTS

In the 7-week group, a decrease in the percentage of IIA, with an increase in IIB and I fiber types, was found in the EDL muscle. Capillary density was not reduced, but endothelial cells showed surface infoldings into the lumen. Altered mitochondria and an infiltrate of macrophages was present in pericytes. In the 14-week group, a decrease in capillary to fiber index was found in both soleus and EDL muscles. EDL fiber type changes were the same as at 7 weeks. The soleus muscle showed an increased percentage of type I fibers. Some capillaries were degenerated, and others showed an increase in the endothelial cell area covered with pericytes, which resembled smooth muscle cells.

CONCLUSION

Hypertensive rats showed changes in the percentage of fiber types in the soleus and EDL muscles. Capillaries adjacent to muscle fibers were reduced and showed morphological changes that resembled arterioles.

Effect of vasoactive drugs on muscle fibre types and capillaries

The effect of nitroglycerin, nifedipine, diltiazem or propranolol on fibre types and capillaries was studied in extensor digitorum longus (EDL) and soleus (S) muscles of the rat. In EDL muscle nifedipine increased the proportion of type I fibres (7.9% +/- 1.7 vs. 4.7% +/- 2.7). Nitroglycerin and dialtiazem decreased IIB fibres (40.7% +/- 10.6 and 37.3% +/- 14.6 respectively vs. 52.3% +/- 9.4). Propranolol increased IIB fibres to 66.3% +/- 8.1, while reducing IIA fibres (25.3% +/- 6.6 vs. 42.2% +/- 6.9). No changes in fibre type proportion were found in S muscle. Capillary density was increased in EDL by nitroglycerin (965 +/- 171 vs. 818 +/- 98 cap/mm2). Propranolol had a dual effect on this parameter, decreasing it in EDL to 570 +/- 85 and augmenting it in S (754 +/- 117 vs. 601 +/- 121). No change was found in capillary to fibre ratio with any of the drugs either in EDL or S muscles. In EDL all the drugs except propranolol, which had the opposite effect, decreased the area of IIA fibre per capillary around 20%; this effect can be interpreted as a reduction of diffusion distance from blood to fibre.

Primary papillary psammomatous adenocarcinoma of the umbilicus

The histological and ultrastructural features, as well as the immunoreactivity of one case of uncommon primary papillary and psammomatous adenocarcinoma of the umbilicus are studied in the present work. The observations have been undertaken in a nine-year follow-up, and have included the primitive tumour, two local recidives, and inguinal lymphatic metastasis on two occasions. Papillary structures, numerous psammoma bodies, as well as weak and focal positive reactions to CEA and cytokeratin were present in all the tumours. Since these features and their ultrastructural characteristics were identical to primary papillary serous neoplasias of the peritoneum and ovarium, the hypothesis of an origin in coelomic remnants is considered.