Acute Chagas' disease in a recipient of a bone marrow transplant in Spain: case report

Chagas' disease (American trypanosomiasis) is a very uncommon disease in non-endemic areas. A few cases in immunosuppressed patients have been reported in America. This report describes, to our knowledge, the first fatal case of acute Chagas' disease in Europe following bone marrow transplantation.

Cholinergic somata and terminals in the rat substantia nigra: an immunocytochemical study with optical and electron microscopic techniques

The topographical distribution, histochemical characteristics, and anatomical relationships of the cellular elements containing choline acetyltransferase (ChAT) immunoreactivity, demonstrated with specific monoclonal antibodies to ChAT following the unlabelled antibody peroxidase-antiperoxidase (PAP) procedure at the optical and electron microscopic levels, were investigated in the rat substantia nigra (SN). Scarce, large (20-30 microns in maximum soma extent) cholinergic cell bodies and processes were found within the boundaries of the SN, in the borders of the pars compacta and pars reticulata, principally at caudal levels. Occasionally, cholinergic neurons were also found at intermediate levels of the SN, in the borders of the pars reticulata and pars lateralis. Cytologically, these large cells resembled ChAT-positive neurons localized in other areas of the central nervous system (CNS) of the rat--for example, the pontomesencephalotegmental (PMT) cholinergic complex (Ch5-Ch6) and the nucleus basalis of Meynert (nbM) (Ch4). Histochemically, ChAT-positive cells in the SN were characterized by their ability to utilize the reduced cofactor nicotinamide adenine dinucleotide phosphate (NADPH). Identified ChAT-positive neurons in the light microscope were subsequently studied in the electron microscope. All cholinergic neurons in the SN share essentially the same ultrastructural characteristics. The copious cytoplasm was rich in organelles with large lipofuscin granules. The synaptic input onto cell bodies and their dendrites was studied in serial sections. Synaptic contacts onto the perikarya and proximal dendrites were sparse and of asymmetric type. Both symmetric and asymmetric synaptic specializations onto ChAT-positive distal dendrites were detected. Asymmetric synaptic contacts onto cell bodies and dendrites were often defined by the presence of subjunctional dense bodies associated with the postsynaptic membrane. The pattern of the synaptic input to these cells differs strikingly from that onto unlabelled neighboring neurons. The perikarya and dendrites of the latter were characteristically covered with synaptic boutons. Scarce immunoreactive terminals in asymmetric synaptic contact with unlabelled dendritic profiles were also detected in portions of SN compacta with no ChAT-positive cells. Extranigrally located ChAT-positive cells of the PMT cholinergic complex were also examined in the electron microscope for comparison purposes. These cells exhibited, on the basis of their morphology and synaptic input pattern, very similar characteristics to those shown by SN cholinergic neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Presence of calcitonin gene-related peptide (CGRP) and substance P (SP) immunoreactivity in intraepidermal free nerve endings of cat skin

Immunocytochemistry against neuropeptides contained within primary afferent neurons was used to study the morphology and distribution of intraepidermal free nerve endings in cat facial skin. Calcitonin gene-related peptide (CGRP) and substance P (SP) immunoreactivity was found in similar intraepidermal nerve endings of cat glabrous and hairy skin epithelia. The greatest density of immunoreactive intraepidermal nerve endings was located in the nose epidermis. Small limited areas with immunoreactive intraepidermal nerve endings were also found in facial hairy skin.

Forest carbon sink neutralized by pervasive growth-lifespan trade-offs

Land vegetation is currently taking up large amounts of atmospheric CO₂, possibly due to tree growth stimulation. Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century. However, there are indications that increased growth rates may shorten trees' lifespan and thus recent increases in forest carbon stocks may be transient due to lagged increases in mortality. Here we show that growth-lifespan trade-offs are indeed near universal, occurring across almost all species and climates. This trade-off is directly linked to faster growth reducing tree lifespan, and not due to covariance with climate or environment. Thus, current tree growth stimulation will, inevitably, result in a lagged increase in canopy tree mortality, as is indeed widely observed, and eventually neutralise carbon gains due to growth stimulation. Results from a strongly data-based forest simulator confirm these expectations. Extant Earth system model projections of global forest carbon sink persistence are likely too optimistic, increasing the need to curb greenhouse gas emissions.

Immunocytochemical analysis of calcitonin gene-related peptide and vasoactive intestinal polypeptide in Merkel cells and cutaneous free nerve endings of cats

Calcitonin gene-related peptide (CGRP)- and vasoactive intestinal polypeptide (VIP)-immunoreactivity were observed to coexist in Merkel cells of cats. No differences in peptide content were found between Merkel cells located in epithelia of the hard palate, in hairy and glabrous skin of the upper lip, and in vibrissae follicles. CGRP- and VIP-immunoreactive nerve fibres were also found near CGRP/VIP-immunoreactive Merkel cells. In the vibrissae follicles some CGRP- and VIP-immunoreactive nerve terminals end abutting on the glassy membrane. Other CGRP-immunoreactive nerve fibres penetrate the epithelium of the skin and end within it. Electron microscopy of vibrissae follicles revealed that Merkel cell neurites are not immunostained and that immunostained nerve fibres form unmyelinated bundles before ending freely. Thus, CGRP- and VIP-immunoreactive nerve fibres in cat skin do not end as Merkel cell neurites but as different kinds of free nerve endings.

Diminished anticoagulant and fibrinolytic activity following liver transplantation

This study analyzed the coagulation changes in twenty patients after orthotopic liver transplantation. The procoagulant, anticoagulant, and fibrinolytic systems were studied during the first two postoperative weeks. Within the first postoperative day all extrinsic and intrinsic pathway factors became normal except factors IX, VII, and X, which recovered within the next 24 hr. Of interest are the changes in factor VIII, which reached a high concentration with an increase in its antigenic fraction during the study. However, coagulation inhibitors showed a different pattern. In fact, antithrombin III (AT-III) and protein C (PC) needed from 7 to 14 days to reach normal values. Total protein S (TPS) and free protein S (FPS) did not recover until day 7, whereas heparin cofactor II (HC-II) remained at subnormal levels throughout the study. Thrombin-antithrombin III complex (TAT) values were strikingly elevated in the immediate postoperative period. Fibrinolysis parameters showed plasminogen (PL) levels in the normal range until day 4. Antiplasmin (AP) followed a curve parallel to that of plasminogen but its levels were higher during this observation period. Similarly the initial elevation in plasminogen activator inhibitor 1 endothelial type (PAI-1) levels remained high until days 4 and 7. In summary, it can be concluded that during the postoperative phase after OLT a hypercoagulable state is developed as a result of diminished anticoagulant and fibrinolytic activity. This coagulation might be a nontechnical factor contributing to the thrombotic vascular complications of some liver recipients.

A 3620-Year Temperature Record from Fitzroya cupressoides Tree Rings in Southern South America

A tree-ring width chronology of alerce trees (Fitzroya cupressoides) from southern Chile was used to produce an annually resolved 3622-year reconstruction of departures from mean summer temperatures (December to March) for southern South America. The longest interval with above-average temperatures was from 80 B.C. to A.D. 160. Long intervals with below-average temperatures were recorded from A.D. 300 to 470 and from A.D. 1490 to 1700. Neither this proxy temperature record nor instrumental data for southern South America for latitudes between 35 degrees and 44 degrees S provide evidence of a warming trend during the last decades of this century that could be related to anthropogenic causes. The data also indicate that alerce is the second longest living tree after the bristlecone pine (Pinus Iongaeva).

Distribution of enkephalin-immunoreactive nerve fibres and terminals in the region of the nucleus basalis magnocellularis of the rat: a light and electron microscopic study

This investigation was carried out on the distribution of enkephalin-containing nerve fibres and terminals in the region of the nucleus basalis magnocellularis (NBM) of the rat. At the light microscope (LM) level, enkephalin-immunoreactive sites and endogenous choline acetyltransferase (ChAT) were demonstrated by employing the two-colour immunoperoxidase staining technique, using highly specific monoclonal antibodies against enkephalin and ChAT. A pharmacohistochemical procedure to reveal acetylcholinesterase (AChE)-synthesizing neurons combined with the peroxidase-antiperoxidase (PAP) immunocytochemical technique to detect endogenous enkephalins, provided ultrastructural data on the relationships of neuronal elements containing AChE and enkephalins in the region of the NBM. At the LM level, cholinergic neurons of the NBM were surrounded by a dense network of enkephalin-immunoreactive nerve fibres. Electron microscopic (EM) observations of histochemically characterized structures, that were first identified in the LM, revealed that intensely AChE-stained structures in the region of the NBM received sparse synaptic inputs from enkephalin immunoreactive terminals. Synaptic inputs of immunoreactive terminals onto intensely AChE-stained neuron cell bodies were not detected. Synaptic contacts onto proximal AChE-positive dendrites were sparse, but the density increased on more distal regions of the dendrites. All immunoreactive boutons studied established symmetrical synaptic contacts with AChE-positive post-synaptic structures. The pattern of the synaptic input to these cells differs strikingly from that onto typical globus pallidus neurons. The perikarya and dendrites of the latter neurons were characteristically ensheathed in immunoreactive synaptic boutons. Results are consistent with the view that enkephalin-like substances in the rat might be synaptic transmitters or neuromodulators in the area of the NBM and that cholinergic neurons of the NBM (Ch4) are integrated into the circuitry of the basal ganglia. Enkephalins may play an important role regulating the extrinsic cholinergic innervation of the neocortex.

Endotoxin-induced pulmonary dysfunction is prevented by C1-esterase inhibitor

In septic shock, hypotension, disseminated intravascular coagulation, and neutrophil activation are related to the activation of the blood coagulation contact system. This study evaluates in dogs the effect of the C1-esterase inhibitor (C1-INH), a main inhibitor of the blood coagulation contact system, on the cardiovascular and respiratory dysfunction associated with endotoxic shock. Two groups were included: controls, which received Escherichia coli endotoxin, and a C1-INH group in which C1-INH was infused before E. coli endotoxin administration. In both groups, endotoxin produced hypodynamic shock; however, the decrease in the systolic index and the ventricular systolic work indexes were greater in controls than the C1-INH group. In controls, the arterial O2 partial pressure decreased by 30% and the alveolo-arterial O2 difference increased by 625%, these parameters remained unchanged in the C1-INH group. Hypoxemia was associated with increased intrapulmonary shunt, decreased blood coagulation contact factors, and decreased C3c. In contrast, C1-INH administration prevented endotoxin-induced hypoxemia, the increase in intrapulmonary shunt, and the decrease in blood coagulation contact factors. This study shows that, in dogs with endotoxic shock, pulmonary dysfunction is associated with an activation of the blood coagulation contact phase system. An inhibition of this system by C1-INH prevented the hypoxemia induced by endotoxic shock.

Febrile ulceronecrotic Mucha-Habermann disease: a case report and review of the literature

A 32-year-old male with febrile ulceronecrotic Mucha-Habermann disease (FUMHD) responsive to methotrexate is reported. This is a severe variant of pityriasis lichenoides et varioliformis acuta characterized by the acute onset of a widespread ulceronecrotic cutaneous eruption together with high fever and systemic involvement. To our knowledge, only 13 patients with FUMHD have been reported to date.

Repetitive self-injurious behavior: a neuropsychiatric perspective and review of pharmacologic treatments

The phenomenology, pathophysiology, and psychopharmacology of repetitive self-injurious behavior (rSIB) are reviewed. Although numerous neurotransmitter systems are thought to be involved in the initiation and maintenance of rSIB, the majority of clinical studies attend to the role of serotonin or endogenous opioids. This focus has emerged from a conceptualization of rSIB as a problem of impulse control (primarily mediated by serotonin) and/or as a maladaptive pain-related behavior (ultimately mediated by opioids). A developmental perspective of rSIB is emphasized, highlighting the biased prevalence of rSIB among patients with mental retardation and severe personality disorders and the significance of critical developmental events leading to pathology in "pedagogical" neural circuits. A novel typology is offered in an effort to better match interventions with rSIB subtypes. Achievement of this ultimate goal however, must await further research.

Protein C, protein S and C4b-binding protein in neonatal severe infection and septic shock

We have studied the behaviour of total protein S, free protein S, protein C and C4b-binding protein fifteen neonates with severe infections, eight with septic shock and in a group of ten healthy newborns. Protein C was decreased in shock and septic patients, but only the shock group showed significant differences compared to normal neonates. Total protein S was normal in both groups of patients, although free protein S had significantly lower values in shock and nonshock infants. C4b-binding protein was higher than normal in septic and shock patients compared to the control group. Decreased values of protein C and free protein S can be explained by the activation of coagulation and their subsequent consumption. On the other hand, the increased levels of C4b-binding protein can affect the distribution of protein S in plasma, producing a shift in protein S to the complexed inactive form. These findings can contribute to an increased risk of microthrombosis during neonatal sepsis.

Different response of astrocytes and Bergmann glial cells to portacaval shunt: an immunohistochemical study in the rat cerebellum

The present study was performed in order to follow the response of rat cerebellum astroglial cells (Bergmann glial cells and astrocytes) to long-term portacaval shunt (PCS), by means of glial fibrillary acidic protein (GFAP) and vimentin immunoreactivities. Bergmann glia accumulated GFAP in response to PCS, whereas astrocytes decreased GFAP immunoreactivity when compared to control rats. The increase of GFAP occurs in cells located in the cerebellar layer where glutamate is mainly released. Since the vimentin content remained unaltered in response to PCS, when compared to control rats, it can be concluded that only the GFAP filaments are affected by PCS. Nevertheless, GFAP immunoreactivity presents regional differences in the cerebellar astroglial population, and the factors responsible for these variations are still unknown.

Cryopreservation increases apoptosis in human menisci

PURPOSE

Removal of the meniscus leads to progressive degenerative arthritis of the knee on a long-term basis; therefore, meniscal allograft transplantation has been proposed as an alternative to meniscectomy. Preservation methods are required to build up operational stocks and to provide living grafts of a practical size at the right time for patients. Methods for meniscus preservation have been published, and relevant literature confirms that using standard cryopreservation, the chondrocyte survival in situ is inadequate and extremely variable and the cryoinjury mechanisms are not completely established. The aim of the present study is to further investigate possible cellular injury caused by cryopreservation by analysing apoptosis and ultrastructural damage to menisci.

METHODS

Seven human menisci that were cryopreserved by standard method were used. All tissue samples were processed simultaneously for routine light microscopy, scanning and transmission electron microscopy as well as apoptosis assessment by the use of ISOL method.

RESULTS

With respect to cellularity, significant differences (P < 0.05) between the fresh (14.6 ± 3.5) (mean ± SD) and cryopreserved menisci (9.2 ± 2.8) (mean ± SD) were observed. Apoptosis using ISOL method was observed in fibrochondrocytes of fresh and cryopreserved menisci. The quantitative analysis revealed significant differences (P < 0.05) between fresh meniscus samples, where the apoptotic index was 0.8 ± 2.3% (mean ± SD), and cryopreserved meniscus samples, where this index was 50 ± 18.1% (mean ± SD).

CONCLUSION

The results suggest that apoptosis occurs during meniscus cryopreservation. The major findings of this study are cellular damage in meniscus cryopreservation suggesting apoptosis-mediated cell loss. The findings reported herein encourage to further investigations in preservation procedures to enhance maximum long-term clinical survival.

Detection of antibodies to Candida albicans germ tube as a possible aid in diagnosing systemic candidiasis in bone marrow transplant patients

Indirect immunofluorescence assays to detect antibodies to Candida albicans blastospore and germ tube were performed in sera of 29 bone marrow transplant patients. Antibodies to germ tube were present in the sera of six patients, in four of whom a Candida albicans infection was highly probable, while in the other two patients it was not possible to determine the previous course. No healthy blood donors had these antibodies. On the other hand, detection of antibodies to Candida albicans blastospore showed low specificity in the diagnosis of systemic candidiasis. These preliminary findings suggest that the detection of antibodies to Candida albicans germ tube may be an important aid in the diagnosis of systemic candidiasis in bone marrow transplant patients.

Characterization of ultrastructural damage of valves cryopreserved under standard conditions

Cryopreserved allograft valves are increasingly being used as valvular replacements. This study was conducted to characterize the ultrastructural damage on the allograft valves obtained by a current standard protocol of valve procurement, antibiotic exposure, and cryopreservation, as a basis for future studies on allograft valve preservation. Materials used were seven aortic and seven pulmonary fresh porcine valves, which were cryopreserved according to the requirements of the American and European Associations of Tissue Banks. The samples were randomly assigned into four groups: (1) fresh, untreated; (2) fresh, treated with antibiotics for 24 h.; (3) treated with antibiotics and exposed to dimethyl sulfoxide (without freezing); and (4) treated with antibiotics, exposed to dimethyl sulfoxide, and then cryopreserved and stored until the study. All tissue samples were processed simultaneously for routine light microscopy and transmission electron microscopy. Fresh-untreated, antibiotic-treated, and dimethyl sulfoxide-exposed valves showed adequate preservation of cellular components. However, after cryopreservation significant damage was observed in fibroblasts with signs of apoptotic cellular injury. Our observation suggests that apoptosis occurs during valve processing. This apoptotic process may be related to various factors, including chemical injury or hypoxia.

Keratocyte injury in human corneas cryopreserved under standard conditions

This study was conducted to characterize ultrastructural damage to human corneas cryopreserved by a standard protocol. The materials used were seven human corneas that were unsuitable for transplantation due to the presence of positive bacteriological cultures; they were cryopreserved according the standard procedure. After freezing and thawing, samples were obtained for scanning and transmission electron microscopy studies. Marked damage was observed in keratocytes with signs of apoptotic cellular injury. However our observations have shown that apoptosis contribute less significantly than necrosis to cellular death in keratocytes of human corneas and although the control of apoptosis is clearly desirable, in order to improve the success of cryopreserved corneas for transplant, we need to continue our investigation to reduce the effects of the necrotic process.

In vitro susceptibility of Mycobacterium avium to a new macrolide (RU-28965)

The in vitro susceptibility of Mycobacterium avium to RU-28965 alone and in combination with rifampin, isoniazid, and sulfametoxipiridazine was studied by the agar dilution method. The synergistic effect of the RU-28965 with rifampin has been demonstrated. At a concentration of 16 micrograms/ml or lower of RU-28965, 100% of M. avium strains were inhibited. If 2 micrograms/ml of rifampin is added the MIC of RU-28965 is lowered to 0.25 microgram/ml.

Cryopreservation of human skin with propane-1,2-diol

The tolerance and cryoprotective effect of propane-1,2-diol on human skin was evaluated using tetrazolium reductase enzyme activity to assess tissue viability. The tolerance of human skin was tested by exposing the skin to increasing concentrations of propane-1,2-diol (10, 20, and 40% v/v), at two permeation temperatures (4 degrees C or room temperature), in a stepwise manner, to reduce osmotically induced changes in cell volume. There was no evidence of specific toxicity attributable to the cryoprotectant during the permeation period, even at a concentration of 40%; however a significant decrease in human skin viability was observed after freezing and thawing with high concentrations of cryoprotectant. The only useful protocol was that employing a low cooling rate (-1 degree C min-1) with 10 or 20% (v/v) propane-1,2-diol at a low permeation temperature. The data suggest that propane-1,2-diol does not produced improved results when compared with other cryoprotectants used for skin cryopreservation.

Streamflow variations across the Andes (18°-55°S) during the instrumental era

The rivers originating in the southern Andes (18°-55°S) support numerous ecosystems and a large number of human populations and socio-economic activities in the adjacent lowlands of Chile, Argentina and Bolivia. Here we show that ca. 75% of the total variance in the streamflow records from this extensive region can be explained by only eight spatially coherent patterns of variability. Five (three) of these Andean patterns exhibit extreme dry (wet) conditions in recent years, with strong interannual variations in northern Chile; long-term drying trends between 31° and 41°S; a transitional pattern in the central Patagonian Andes; and increasing trends in northwestern Argentina and southern Bolivia, the Fueguian Andes, and the eastern portion of the South Patagonian Icefield. Multivariate regression analyses show that large-scale indices of ENSO variability can predict 20% to 45% of annual runoff variability between 28° and 46°S. The influence of Antarctic and North Pacific indices becomes more relevant south of 43°S and in northwestern Argentina and southern Bolivia, respectively, but their overall skill as predictors of Andean streamflows is weak. The analyses provide relevant new information to improve understanding of the spatial coherence, the main temporal features, and the ocean-atmospheric forcings of surface runoff across the southern Andes.

Flex center method versus center method for endothelial corneal evaluation in eye banking: a comparative analysis

Specular microscopy can provide a non-invasive morphological analysis of the cornea endothelial cell layer. A variety of analysis programs are available to determine corneal endothelial quality. The flex-center endothelial analysis method (Konan Inc) is a newer technique including the outermost digitized cells and thus increases the number of cells for analysis. The aim of this study is to analyze whether the new flex-center method, increases the possibilities of corneal endothelium evaluation before implants. For this purpose 67 corneas were studied by both methods at the Eye Bank of the Tissue Establishment of Córdoba. Although we have found differences in the resulting of number of cells in the area analysed, no significant differences were found with respect to the endothelial cell count, coefficient of variation cell area, and the percentage of hexagonal cells recorded. Based on this data, both methods can be used satisfactorily in eye banking.

Microbiological analysis of cryopreserved human heart valves after storage: a survey of 3 banks in Spain

Several reports have shown liquid nitrogen containers as not being sterile. Microorganism transmission has been observed in different cells and tissues stored under this condition, but there is no data on contamination of stored human valves. We performed a survey on heart valve banking in Spain. Regarding the questionnaire, we have a complete microbiological analysis of 304 thawed tissues prior to implant. In six cases positive culture results were observed. Patient follow-up did not reveal any adverse effects. Although some other possibilities should be stated, contamination of heart valves during storage in liquid nitrogen should be considered as a risk element in tissue banking. Strategies to asses and prevent microbial transmission from liquid nitrogen to heart valve banking ought to be further developed.