Follow-up assessment of patients with Pure Neural Leprosy in a reference center in Rio de Janeiro—Brazil

IntroductionPure Neural Leprosy (PNL) is a rare clinical form of leprosy in which patients do not present with the classical skin lesions but have a high burden of the disability associated with the disease. Clinical characteristics and follow up of patients in PNL are still poorly described in the literature.ObjectiveThis paper aims to describe the clinical, electrophysiological and histopathological characteristics of PNL patients, as well as their evolution after multidrug therapy (MDT).MethodsFifty-two PNL patients were selected. Clinical, nerve conduction studies (NCS), histopathological and anti-PGL-1serology were evaluated. Patients were also assessed monthly during the MDT. At the end of the MDT, all of the patients had a new neurological examination and 44 were submitted to another NCS.ResultsParesthesia was the complaint most frequently reported by patients, and in the neurological examination the most common pattern observed was impairment in sensory and motor examination and a mononeuropathy multiplex. Painful nerve enlargement, a classical symptom of leprosy neuropathy, was observed in a minority of patients and in the motor NCS axonal injuries, alone or in combination with demyelinating features, were the most commonly observed. 88% of the patients did not present any leprosy reaction during MDT. There was no statistically significant difference between the neurological examinations, nor the NCS pattern, performed before and after the MDT.DiscussionThe classical hallmarks of leprosy neuropathy are not always present in PNL making the diagnosis even more challenging. Nerve biopsy is an important tool for PNL diagnosis as it may guide therapeutic decisions. This paper highlights unique characteristics of PNL in the spectrum of leprosy in an attempt to facilitate the diagnosis and management of these patients.     

Defective hematopoietic differentiation of immune aplastic anemia patient-derived iPSCs

In acquired immune aplastic anemia (AA), pathogenic cytotoxic Th1 cells are activated and expanded, driving an immune response against the hematopoietic stem and progenitor cells (HSPCs) that provokes cell depletion and causes bone marrow failure. However, additional HSPC defects may contribute to hematopoietic failure, reflecting on disease outcomes and response to immunosuppression. Here we derived induced pluripotent stem cells (iPSCs) from peripheral blood (PB) erythroblasts obtained from patients diagnosed with immune AA using non-integrating plasmids to model the disease. Erythroblasts were harvested after hematologic response to immunosuppression was achieved. Patients were screened for germline pathogenic variants in bone marrow failure-related genes and no variant was identified. Reprogramming was equally successful for erythroblasts collected from the three immune AA patients and the three healthy subjects. However, the hematopoietic differentiation potential of AA-iPSCs was significantly reduced both quantitatively and qualitatively as compared to healthy-iPSCs, reliably recapitulating disease: differentiation appeared to be more severely affected in cells from the two patients with partial response as compared to the one patient with complete response. Telomere elongation and the telomerase machinery were preserved during reprogramming and differentiation in all AA-iPSCs. Our results indicate that iPSCs are a reliable platform to model immune AA and recapitulate clinical phenotypes. We propose that the immune attack may cause specific epigenetic changes in the HSPCs that limit adequate proliferation and differentiation.Subject terms: Anaemia, Induced pluripotent stem cells     

Length–weight relationships of 26 fish species from the middle section of the Negro River (Tacuarembó‐Durazno,Uruguay)

This study provides data on the length–weight relationship (LWR) for 26 species of neotropical fishes. Specimens were collected between 2008 and 2009 from a dam‐enclosed section of the middle Negro River (Uruguay). This study represents the first reference on length–weight relationships for 17 species, and also provides new maximum sizes for eight species.     

Effect of airflow rate on yields of Steinernema carpocapse Az 20 in liquid culture in an external-loop airlift bioreactor

Maximization of the contact between males and females is a key factor in the production of the nematode Steinernema carpocapsae in a bioreactor.%The influence of the airflow rate in male and female distribution and mass production in an external-loop bioreactor with a deceleration zone was studied. When operating at an airflow rate of 0.05 vvm, a high retention of females in the deceleration zone of the bioreactor was observed and a larger nematode productivity was obtained. At this aeration rate there was a higher proportion of males in that zone, which together with the lower circulation rate, increases the probability of encounters, thereby explaining the increase in productivity.     

Trypanosoma cruzi prolyl oligopeptidase Tc80 is involved in nonphagocytic mammalian cell invasion by trypomastigotes

Trypanosoma cruzi is an intracellular protozoan parasite able to invade a wide variety of mammalian cells. To have access to the target organs/cells, the parasite must cross the basal laminae and the extracellular matrix (ECM). We previously characterized an 80-kDa proteinase (Tc80) secreted by the infective trypomastigotes that hydrolyzes native collagens and might be involved in infection by degrading ECM components. Here, we present evidence indicating a role for Tc80 in the invasion of nonphagocytic cells. Tc80 was classified as a member of the prolyl oligopeptidase (POP) family of serine proteases and was also found to hydrolyze fibronectin. Selective inhibitors for POP Tc80 were synthesized that blocked parasite entry into cells. Blockage occurred when trypomastigotes were preincubated with irreversible inhibitors but not after host cell preincubation, and the blockage correlated with inhibition of POP Tc80 activity in treated parasites. These data and the enzyme location inside a vesicular compartment close to the flagellar pocket, a specialized domain in endocytosis/exocytosis, strongly suggest a role for POP Tc80 in the maturation of parasite protein(s) and/or, after secretion, in a local action on parasite or host cell/ECM components required for invasion.     

Data on the family Pandalidae around the Canary Islands, with first record of Plesionika antigai (Caridea)

Of the 20 pandalid shrimps species and subspecies reported for the Eastern Central Atlantic (26–36° N), 16 were found in one or more Macaronesian archipelagos (Azores, Madeira, Canary Islands and Cape Verde Islands) (14–40° N), and 11 of them were recorded to date in the Canary Island waters (27° 30–29° 30 N): Bitias stocki Fransen, 1990; Heterocarpus ensifer ensifer A. Milne-Edwards, 1881; Heterocarpus grimaldii A. Milne-Edwards & Bouvier, 1900; Heterocarpus laevigatus Bate, 1888; Plesionika edwardsii (Brandt, 1851); Plesionika ensis (A. Milne-Edwards, 1881); Plesionika holthuisi Crosnier & Forest, 1968; Plesionika martia martia (A. Milne-Edwards, 1883); Plesionika narval (J.C. Fabricius, 1787); Plesionika williamsi Forest, 1964; and Stylopandalus richardi Coutière, 1905. In the present work, Plesionika antigai Zariquiey Álvarez, 1955 is recorded for the first time from the Canary Islands. As a result of many fishing surveys around the Canary Islands at 27–1550 m depth between 1985 and 1998, information on bathymetric distribution, habitat, size and biology of the 12 Canarian pandalid species is given. The geomorphologic, geographic and oceanographic characteristics of the Canary Islands marine ecosystems could explain the great diversity in the biogeographic patterns of the pandalid species inhabiting this area. The distribution patterns found were: Macaronesian (1 spec.), Atlanto-Mediterranean (1 spec.), Eastern Atlantic warm-temperate (1 spec.), amphi-Atlantic warm (2 spec.), amphi-Atlantic warm-temperate (1 spec.), pantropical (5 spec.), and cosmopolitan (1 spec.).     

Role of sodium channel deglycosylation in the genesis of cardiac arrhythmias in heart failure

We investigated the cellular and molecular mechanisms underlying arrhythmias in heart failure. A genetically engineered mouse lacking the expression of the muscle LIM protein (MLP-/-) was used in this study as a model of heart failure. We used electrocardiography and patch clamp techniques to examine the electrophysiological properties of MLP-/- hearts. We found that MLP-/- myocytes had smaller Na+ currents with altered voltage dependencies of activation and inactivation and slower rates of inactivation than control myocytes. These changes in Na+ currents contributed to longer action potentials and to a higher probability of early afterdepolarizations in MLP-/- than in control myocytes. Western blot analysis suggested that the smaller Na+ current in MLP-/- myocytes resulted from a reduction in Na+ channel protein. Interestingly, the blots also revealed that the alpha-subunit of the Na+ channel from the MLP-/- heart had a lower average molecular weight than in the control heart. Treating control myocytes with the sialidase neuraminidase mimicked the changes in voltage dependence and rate of inactivation of Na+ currents observed in MLP-/- myocytes. Neuraminidase had no effect on MLP-/- cells thus suggesting that Na+ channels in these cells were sialic acid-deficient. We conclude that deficient glycosylation of Na+ channel contributes to Na+ current-dependent arrhythmogenesis in heart failure.     

A novel scenario for the evolution of haem-copper oxygen reductases

The increasing sequence information on oxygen reductases of the haem-copper superfamily, together with the available three-dimensional structures, allows a clear identification of their common, functionally important features. Taking into consideration both the overall amino acid sequences of the core subunits and key residues involved in proton transfer, a novel hypothesis for the molecular evolution of these enzymes is proposed. Three main families of oxygen reductases are identified on the basis of common features of the core subunits, constituting three lines of evolution: (i) type A (mitochondrial-like oxidases), (ii) type B (ba3-like oxidases) and (iii) type C (cbb3-type oxidases). The first group can be further divided into two subfamilies, according to the helix VI residues at the hydrophobic end of one of the proton pathways (the so-called D-channel): (i) type A1, comprising the enzymes with a glutamate residue in the motif -XGHPEV-, and (ii) type A2, enzymes having instead a tyrosine and a serine in the alternative motif -YSHPXV-. This second subfamily of oxidases is shown to be ancestor to the one containing the glutamate residue, which in the Bacteria domain is only present in oxidases from Gram-positive or purple bacteria. It is further proposed that the Archaea domain acquired terminal oxidases by gene transfer from the Gram-positive bacteria, implying that these enzymes were not present in the last common ancestor before the divergence between Archaea and Bacteria. In fact, most oxidases from archaea have a higher amino acid sequence identity and similarity with those from bacteria, mainly from the Gram-positive group, than with oxidases from other archaea. Finally, a possible relation between the dihaemic subunit (FixP) of the cbb3 oxidases and subunit II of caa3 oxidases is discussed. As the families of haem-copper oxidases can also be identified by their subunit II, a parallel evolution of subunits I and II is suggested.     

Metabolic fate of AMP, IMP, GMP and XMP in the cytosol of rat brain: an experimental and theoretical analysis

A systematic study of the metabolic fate of AMP, IMP, GMP and XMP (NMP) in the presence of cytosol from rat brain is here presented; the kinetics of both disappearance of NMP, and appearance of their degradation products was followed by HPLC. In the absence of ATP, AMP was preferentially degraded to adenosine with concomitant appearance of inosine and hypoxanthine. In the presence of ATP, AMP was preferentially degraded via IMP. The nucleosides generated in the course of the reactions are further degraded, almost exclusively, via nucleoside phosphorylase using as cofactor the P(i) generated in the reaction mixture. In order to quantify the effect of each one of the enzymes involved in the degradation of NMP, two complementary approaches were followed: (i) the V:(max) and K:(m) values of the enzymes acting in the intermediate steps of the reactions were determined; (ii) these data were introduced into differential equations describing the concentration of the nucleotides and their degradation products as a function of the time of incubation. Factors affecting kinetic parameters of the equation velocity as a function of ATP concentration were introduced when required. The differential equations were solved with the help of Mathematica 3.0. The theoretical method can be used to simulate situations not feasible to be carried out, such as to measure the influence of nM-microM concentrations of ATP on the metabolism of AMP.     

Effect of insulin on exocrine pancreatic secretion in healthy and diabetic anaesthetised rats

This investigation characterised the effects of exogenous insulin on exocrine pancreatic secretion in anaesthetised healthy and diabetic rats. Animals were rendered diabetic by a single injection of streptozotocin (STZ, 60 mg kg(-1) I.P.). Age-matched controls were injected citrate buffer. Rats were tested for hyperglycaemia 4 days after STZ injection and 7-8 weeks later when they were used for the experiments. Following anaesthesia (1 g kg(-1) urethane I.P.), laparotomy was performed and the pancreatic duct cannulated for collection of pure pancreatic juice. Basal pancreatic juice flow rate in diabetic rats was significantly (p < 0.001) increased whereas protein and amylase outputs were significantly (p < 0.001) decreased compared to control rats. Insulin (1 IU, I.P.) produced in healthy rats significant increases in pancreatic flow rate, amylase secretion and protein output compared to basal (p < 0.05). Insulin action also included a reduction in blood glucose (152.7 +/- 16.9 mg dl(-1), n = 6, prior to insulin and 42.0 +/- 8.4 mg dl(-1), n = 4, 100 min later). In fact, flow rate and glycaemia showed a strong negative correlation (p < 0.01, Pearson). Pretreatment with atropine (0.2 mg kg(-1), I.V.) abolished the effects of insulin on secretory parameters despite a similar reduction in glycaemia; in this series of experiments the correlation between flow rate and blood glucose was lost. In diabetic rats, insulin (4 IU, I.P.) did not modify exocrine pancreatic secretion. There was a fall in blood glucose (467.6 +/- 14.0 mg dl(-1), n = 10, prior to insulin and 386.6 +/- 43.6 mg dl(-1), n = 7, 120 min later). Rats, however, did not become hypoglycaemic. Similar results were observed in diabetic atropinized rats. The results of this study indicate that the effects of insulin on exocrine pancreatic secretion in anaesthetised healthy rats are mediated by hypoglycaemia-evoked vagal cholinergic activation.