Validation of impedance cardiography measurements of cardiac output during limited exercise in heart transplant recipients

Abstract. Twenty-one patients were studied at rest and during exercise after heart transplantation to compare cardiac output measured by thermodilution and impedance cardiography. Exercise was performed on a bicycle ergometer over a limited range of work load (25 and 50 watt) whilst metabolic gas exchange was recorded. One patient was studied at rest whilst his circulation was maintained by a Jarvik-7 artificial heart. The values of cardiac output measured by impedance cardiography corresponded closely with the flow rate from the artificial heart. There was also close agreement between the impedance and thermodilution measurements of cardiac output at rest and during exercise. Both measurements followed the changes in heart rate and oxygen consumption. Both thermodilution and impedance cardiography methods elicited good reproducibility of cardiac output measurements at rest and during exercise. These observations suggest that the noninvasive and continuous record of cardiac output obtained by impedance cardiography can be used for the postoperative monitoring of heart transplant recipients.     

Genetic diversity and molecular identification of mosquito species in the Anopheles maculatus group using the ITS2 region of rDNA.

The species diversity and genetic structure of mosquitoes belonging to the Anopheles maculatus group in Southeast Asia were investigated using the internal transcribed spacer 2 (ITS2) of ribosomal DNA (rDNA). A molecular phylogeny indicates the presence of at least one hitherto unrecognised species. Mosquitoes of chromosomal form K from eastern Thailand have a unique ITS2 sequence that is 3.7% divergent from the next most closely related taxon (An. sawadwongporni) in the group. In the context of negligible intraspecific variation at ITS2, this suggests that chromosomal form K is most probably a distinct species. Although An. maculatus sensu stricto from northern Thailand and southern Thailand/peninsular Malaysia differ from each other in chromosomal banding pattern and vectorial capacity, no intraspecific variation was observed in the ITS2 sequences of this species over this entire geographic area despite an extensive survey. A PCR-based identification method was developed to distinguish five species of the group (An. maculatus, An. dravidicus, An. pseudowillmori, An. sawadwongporni and chromosomal form K) to assist field-based studies in northwestern Thailand. Sequences from 187 mosquitoes (mostly An. maculatus and An. sawadwongporni) revealed no intraspecific variation in specimens from Thailand, Cambodia, mainland China, Malaysia, Taiwan and Vietnam, suggesting that this identification method will be widely applicable in Southeast Asia. The lack of detectable genetic structure also suggests that populations of these species are either connected by gene flow and/or share a recent common history.     

Placenta membranacea, previa and accreta. A case report.

A case of placenta membranacea, previa and accreta was managed conservatively and resulted in delivery of a mature fetus. The diagnosis of placenta membranacea and previa was obtained with ultrasound. The placenta previa and accreta necessitated a cesarean delivery and hysterectomy.     

Expression of tyrosine hydroxylase and neuropeptide tyrosine in mouse sympathetic airway-specific neurons under normal situation and allergic airway inflammation

BACKGROUND: The traditional neurotransmitter catecholamine and the neuropeptide tyrosine in sympathetic airway nerves have been proposed to be involved in the pathogenesis of airway diseases. OBJECTIVE: The aim of the present study was to investigate the effect of allergic airway inflammation on the expression of catecholamine enzyme tyrosine hydroxylase (TH), neuropeptide tyrosine (NPY) and tachykinins in mouse sympathetic airway ganglia. METHODS: Using neuronal tracing in combination with immunohistochemistry, the present study was designed to characterize TH, NPY and tachykinin profiles of superior cervical (SCG) and stellate ganglia after allergen challenge. RESULTS: The vast majority of fast blue-labelled SCG neurons (allergen: 97.5+/-1.22% (mean+/-SEM) vs. controls: 94.5+/-1.48%, P=0.18) and stellate neurons (allergen: 95.3+/-1.01% vs. controls: 93.6+/-1.33%, P=0.34) were immunoreactive for TH. Of the TH immunoreactive and fast blue-labelled SCG neurons, 52.0+/-1.01% allergen vs. 51.2+/-3.58% controls (P=0.83) and stellate neurons, 57.3%+/-0.97 allergen vs. 56.4+/-1.65% controls (P=0.64) were positive for TH only but not NPY, whereas 45.3+/-1.05% allergen vs. 43.3+/-1.18% controls (P=0.47) of fast blue-labelled SCG neurons and 37.9+/-0.86% allergen vs. 37.1+/-1.24% controls (P=0.62) of fast blue-labelled stellate neurons were immunoreactive for both TH and NPY immunoreactivities. There was a trend of an increase, but not significant one, in the percentage of TH-/NPY-immunoreactive and fast blue-labelled neurons in allergen-treated animals in comparison with the controls. Tachykinins, however, were not expressed by sympathetic neurons and were also not induced in sympathetic neurons after allergen challenge. CONCLUSION: The present study indicates that allergic airway inflammation does not alter the expression of noradrenalin and NPY in sympathetic ganglia and also shows that sympathetic neurons do not respond to allergic airway inflammation with tachykinins induction. However, a participation of catecholamine and NPY in the pathogenesis of allergic airway inflammation cannot be excluded in the present study as a higher neurotransmitter output per neuron following allergen challenge could be possible.     

Studies on T cell subsets and functions in leprosy.

T cell subsets and T cell functions were explored in 31 leprosy patients with the following methods: determination of the percentages of the different T cell subpopulations defined by monoclonal antibodies directed at total T cells, helper T cells and suppressor/cytotoxic T cells; measurement of the in vitro proliferative responses to mitogens; study of the concanavalin A-induced suppressive activity, assessed on MLC; measurement of delayed-type hypersensitivity by skin testing. The confrontation between immunological lepromatous patients without type-2 reaction (erythema nodosum leprosum), (2) lepromatous patients without ENL (erythema nodosum leprosum), (2) lepromatous patients was recent ENL and (3) tuberculoid patients. Unexpectedly, groups 1 and 3, although differing strongly in their clinical status and their sensitivity to lepromin (absent in group 1 and strong in group 3), showed a similar immunological profile with a normal percentage of T cells and a normal distribution of T cells among the major T cell subset contrasting with a moderate decrease of proliferative responses to mitogens and impaired delayed-type hypersensitivity reactions. Concanavalin A-induced suppressive activity was type-2 reaction) strongly differed from both other groups, showing striking abnormalities other groups, showing striking abnormalities of the repartition of the T cell subsets, with increased percentages of helper T cells and decreased percentages of suppressor T cells, and elevated proliferative responses to mitogens. Concanavalin A-induced suppressive activity was reduced in most patients of this group. It is suggested that this imbalance between T cell subsets contributes to the occurrence of ENL reactions in lepromatous patients.     

Allergic airway inflammation induces tachykinin peptides expression in vagal sensory neurons innervating mouse airways

BACKGROUND: Allergic airway inflammation has been shown to induce pro-inflammatory neuropeptides such as tachykinin peptides substance P (SP) and neurokinin A (NKA) together with related peptide like calcitonin gene-related peptide (CGRP) in nodose sensory neurons innervating guinea-pig airways. OBJECTIVE: The present study was designed to examine the effects of allergen sensitization and challenge on the SP/NKA expression in the jugular-nodose ganglion neurons innervating the murine airways. METHODS: Using retrograde neuronal tracing technique in combination with double-labelling immunohistochemistry, the expression of SP/NKA was investigated in a murine model of allergic airway inflammation. RESULTS: Allergic airway inflammation was found to induce the expression of SP/NKA (13.2+/-1.43% vs. 5.8+/-0.37%, P<0.01) in large-diameter (>20 microm) vagal sensory neurons retrograde labelled with Fast blue dye from the main stem bronchi. CONCLUSION: Based on the induction of tachykinins in airway-specific large-sized jugular-nodose ganglia neurons by allergic airway inflammation, the present study suggests that allergen sensitization and challenge may lead to de novo induction of tachykinins in neurons. This may partly contribute to the pathogenesis of airways diseases such as allergic airway inflammation.     

Focal chronic ischemia and concomitant migraine: an atypical form of Sturge-Weber angiomatosis?

A young man with a left hemifacial hemangioma had during a six months period about forty left hemispheric neurologic attacks suggestive of classic migraine. The neurologic examination was normal during the attack-free period. The CT scan (fig. 1) and the M.R.I. study (fig. 2) only showed a moderate interhemispheric asymmetry. The left internal carotid angiogram showed subtle anomalies of the venous system (fig. 3). All the neurologic manifestations ceased as soon as therapy by aspirin was initiated. A Positron Emission Tomography (PET) study with the oxygen 15 continuous inhalation technique was performed 7 months after the last attack in order to measure the regional Cerebral Blood Flow (rCBF), Oxygen Extraction Fraction (rOEF) and Oxygen Consumption (rCMRO2). Striking, statistically significant, alterations were observed in the left temporo-parieto-occipital area (fig. 4) consisting of a "misery perfusion" syndrome (rCBF = 28-38 ml/100 g/mn; rOEF = 0.64-0.80), without alteration in the rCMRO2 (Table). A repeated PET study 12 months later was unchanged. The association of local chronic oligemia and ipsilateral facial hemangioma, ipsilateral cerebral hypotrophy and venous anomalies suggested the diagnosis of atypical leptomeningeal angiomatosis of the Sturge-Weber type. The importance and persistence of the hemodynamic alterations suggest that chronic oligemia and, hence, tissue hypoxia may participate in the pathogenesis of the migraine-like attacks. Moreover, local circulatory stasis with thrombotic events may be implicated, as suggested by the apparent efficacy of aspirin.     

Remote metabolic effects of cerebrovascular lesions: magnetic resonance and positron tomography imaging

Summary Combined Positron Emission Tomography (PET) and Proton Magnetic Resonance Imaging (MRI) study were performed in six patients with chronic supratentorial stroke to investigate whether remote hypometabolic regions revealed by PET showed any abnormality on MRI. Either regional oxygen consumption (n=4) or glucose utilization (n=2) were measured using PET and the ¹⁵O steady state ¹⁸FGD technique, respectively. Four patients, with deeply located brain lesions, showed a significant metabolic reduction in the overlying cerebral cortex. In the remaining two patients, affected by a large cortical infarct, there was a significant crossed cerebellar hypometabolism. The MRI weighted by the parameters spin density (), spin lattice (T₁) and spin-spin (T₂) relaxation times were obtained employing various sequences in the same subjects. In no patient did the MRI show any contrast modification in these hypometabolic remote regions, suggesting that subtle loss of tissue and/or biochemical change do not underlie the reduction in metabolic rate.     

Health-related quality of life following percutaneous coronary intervention during the COVID-19 pandemic

Quality of Life Research - During the COVID-19 pandemic, widespread public health measures were implemented to control community transmission. The association between these measures and...