Weaning infants with respiratory syncytial virus from mechanical ventilation through a fuzzy-logic controller

We have previously developed a fuzzy logic controller for weaning adults with chronic obstructive pulmonary disease using pressure support ventilation (PSV). We used the core of our fuzzy logic-based weaning platform and further developed parametrizable components for weaning newborns of differing body size and disease-state. The controller was validated on neonates recovering from congenital heart disease (CHD) while receiving synchronous intermittent mandatory ventilation (SIMV). We wished to compare the efficacy of this controller versus the bedside weaning protocol in children with respiratory syncytial virus pneumonitis/bronchiolitis (RSV) in the pediatric intensive care unit (PICU). The fuzzy controller evaluated the "current" and "trend" weaning status of the newborn to quantitatively determine the change in the SIMV integrated ventilatory setting. For the "current" status it used heart rate (HR), respiratory rate (RR), tidal volume (VT) and oxygen saturation (SaO2), while for the "trend" status the differences of deltaRR/ deltat, deltaHR/ deltat, and deltaSaO2/ deltat recorded between two subsequent time points were utilized. The enumerated vital signs were fuzzified and then probability levels of occurrence were assigned. Individualized "golden" goals for SaO2 were set for each newborn. We retrospectively assessed the charts of 19 newborns, 113+/-128 days old, 5,546+/-2,321 gr body weight, weaning for 99+/-46 days, at 2-hour intervals. The SIMV levels proposed by the fuzzy controller were matched to those levels actually applied. In 60% of the time both values coincided. For the remaining 40%, the controller was more aggressive suggesting lower values of SIMV than the applied ones. The Area under the SIMV curves over time was 1,969+/-1,044 for the applied vs 1,886+/-978 for the suggested levels, respectively. The fuzzy controller adjusted for body size and disease-pattern can approximate the actual weaning course of newborns with RSV.

Effects of electrical stimulation-induced leg training on skeletal muscle adaptability in spinal cord injury

Neuromuscular electrical stimulation has grown in popularity as a therapeutic device for training and an ambulation aid to human paralyzed muscle. Despite its current clinical use, few studies have attempted to concurrently investigate the functional and intramuscular adaptations which occur after electrical stimulation training. Six individuals with a spinal cord injury performed 10 weeks of electrical stimulation leg cycle training (30 min d(-1), 3 d week(-1)). The paralyzed vastus lateralis muscle showed significant alterations in skeletal muscle characteristics after the training, indicated by an improvement in total work output (52-112 kJ; P < 0.05), an increase in fiber cross-sectional area (18 to 41 x 10(2) microm(2); P < 0.05), a reduction in the percentage of type IIX fibers (75% to 12%; P < 0.05), a decrease in myosin heavy chain IIx (68% to 44%; P < 0.05), an increase in capillary density (2-3.5 capillaries around fiber; P < 0.05) and increases in activity levels of citrate synthase (7-16 mU mg(-1) protein) and hexokinase (1.2-2.4 mU mg(-1) protein). This study showed that 10 weeks of electrical stimulation training of human paralyzed muscle induces concurrent improvements in functional capacity and oxidative metabolism.

External power output changes during prolonged cycling with electrical stimulation

This study analysed external power output and physiologic responses in 5 individuals with paraplegia during 40 minutes of electrical stimulation leg cycle exercise. Cycling was performed on a motor-driven isokinetic ergometer that enabled precise determinations of power output. Electrical stimulation was increased to 120-140 mA within the first 5 minutes and remained constant thereafter. Power output increased to 10.7 +/- 3.0 W after 2 minutes, dropped to 5.3 +/- 1.8 W after 6 minutes and subsequently recovered to 8.2 +/- 2.2 and 6.1 +/- 2.3 W after 19.5 and 40 minutes, respectively. Oxygen consumption increased to 0.47 +/- 0.09 l/min after 6 minutes and declined during the second half of the exercise bout. Gross mechanical efficiency after 19.5 minutes was elevated compared with the value after 6 minutes. Heart rate was significantly increased at the end of the trial. The time-dependent variability of power output and physiological responses question the concept of steady state for this form of exercise.

Evolutionary relationships between trematodes and snails emphasizing schistosomes and paragonimids

Snails and digeneans have been associated for at least 200 million years. Their inter-relationships over such a time-span must have been complex and varied. Few studies have attempted to explore these relationships in the light of knowledge of the phylogeny of both host and parasite groups. Here we focus on two important families of digeneans, the Schistosomatidae and the Paragonimidae, for which molecular phylogenies are available. We investigate the types of evolutionary relationships between host and parasite, operating at different phylogenetic depths, that might explain current host specificity and distributions of both associates. Both families of parasites utilise a number of highly diverged gastropod families, indicating that host extensions have featured in their histories. However, schistosomatids and paragonimids show different patterns of association with their snail hosts. As befits the apparently more ancient group, schistosomatids utilise snails from across a wide phylogenetic range within the Gastropoda. The genus Schistosoma itself has experienced one long-range host switch between pulmonates and caenogastropods. By contrast, paragonimids are restricted to two superfamilies of caenogastropods. Despite these differences, modern schistosomatid species appear to be more host specific than are paragonimids and host additions, at the level of host family, are far less common among species of schistosomatids than among paragonimids. Some species of Paragonimus exhibit remarkably low levels of host specificity, with different populations utilising snails of different families. Existing knowledge relating to the phenomenon will be presented in the context of phylogenies of schistosomatids, paragonimids, and their snail hosts. Discussion focuses on the usefulness of current theories of snail-digenean coevolution for interpreting these findings. In the past, much emphasis has been placed on the idea that digeneans engage in a one-to-one arms race with their snail host. We consider that phylogenetic tracking rather than an arms-race relationship might be a common alternative. Not being bound by the restrictions imposed by an arms race, some digeneans might be able to extend to new host species more easily than the literature suggests. Switches into related host taxa are most likely. However, ecologically equivalent but unrelated gastropod hosts may also be exploited. Given the right ecological setting, digeneans are able to switch across considerable phylogenetic distances. Examples from the Paragonimidae and Schistosomatidae are given.

Fuzzy logic controller for weaning neonates from mechanical ventilation

Weaning from mechanical ventilation is the gradual detachment from any ventilatory support till normal spontaneous breathing can be fully resumed. To date, we have developed a fuzzy logic controller for weaning COPD adults using pressure support ventilation (PS). However, adults and newborns differ in the pathophysiology of lung disease. We therefore used our fuzzy logic-based weaning platform to develop modularized components for weaning newborns with lung disease. Our controller uses the heart rate (HR), respiratory rate (RR), tidal volume (VT) and oxygen saturation (SaO2) and their trends deltaHR/deltat, deltaVT/deltat and deltaSaO2/deltat to evaluate, respectively, the Current and Trend weaning status of the newborn. Through appropriate fuzzification of these vital signs, Current and Trend weaning status can quantitatively determine the increase/decrease in the synchronized intermittent mandatory ventilation (SIMV) setting. The post-operative weaning courses of 10 newborns, 82+/-162 days old, were assessed at 2-hour intervals for 68+/-39 days. The SIMV levels, proposed by our algorithm, were matched to those levels actually applied. For 60% of the time both values coincided. For the remaining 40%, our algorithm suggested lower SIMV support than what was applied. The Area Under the Curve for integrated ventilatory support over time was 1203+/-846 for standard ventilatory strategies and 1152+/-802 for fuzzy controller. This suggests that the algorithm, approximates the actual weaning progression, and may advocate a more aggressive strategy. Moreover, the core of the fuzzy controller facilitates adaptation for body size and diversified disease patterns and sets the premises as an infant-weaning tool.

A baseline study on the importance of bovines for human Schistosoma japonicum infection around Poyang Lake, China

We hypothesize that bovine infections are responsible for the persistence of human schistosomiasis transmission in the Yangtze marshlands of China. To test this hypothesis, we are carrying out a comparative intervention among four administrative villages in the Poyang Lake region, Jiangxi Province, two of which are experimental and two are control. The primary design involves treating, at the onset of the study, all the inhabitants in all four villages with praziquantel and all the bovines in two villages (the experimental or intervention villages). Following treatment, rates of reinfection in people of all villages, and in bovines in the experimental villages, will be assessed as will the ongoing prevalence of infection in bovines in the control villages. Before treatment, the prevalence and intensity of infection among humans and bovines was ascertained in the four villages. Our study design and baseline information are presented here, along with a description of the ecology of the study villages.

Cardiovascular responses during arm exercise and orthostatic challenge in individuals with paraplegia

In this study the cardiorespiratory responses during arm crank ergometry (ACE) performed at two submaximal intensities (30% and 50% of heart rate reserve) and moderate orthostatic challenge were investigated in individuals with paraplegia (PARA). The effect of concurrent electrical stimulation (ES)-induced leg muscle contractions on the responses to ACE during orthostatic challenge was also investigated. Eight PARA (T5-T12) and eight able-bodied (AB) individuals participated in this study, however only seven subjects from each group completed all tests and were used in subsequent data analyses. Oxygen uptake (VO2), heart rate (fc), stroke volume (SV) and cardiac output (Qc) were assessed during (1) ACE alone, (2) ACE and lower body negative pressure (ACE + LBNP), and, in PARA only, (3) ACE + LBNP with ES (ACE + LBNP+ ES). In both PARA and AB, ACE + LBNP decreased SV (by 13-18% and 20-23%, respectively) and increased fc (by 13-15% and 16%, respectively) compared to ACE alone. The decrease in SV was greater in AB than in PARA (significant group x trial interaction; both ACE intensities pooled), but there was no difference in the magnitude of increase in fc between groups. ES-induced leg muscle contractions increased SV (up to 16%) but did not change VO2 or Qc. The smaller reduction in SV from ACE to ACE + LBNP in PARA may indicate a mechanism by which adequate central blood volume can be maintained in the face of orthostatic challenge, despite the absence of supraspinal control below the spinal cord lesion. With ES-induced leg muscle contractions, the decrease in SV, which occurred during ACE + LBNP, was reversed via reactivation of the lower limb muscle pump and augmented venous return.

Schistosomiasis in the People's Republic of China: prospects and challenges for the 21st century

Schistosomiasis japonica is a serious communicable disease and a major disease risk for more than 30 million people living in the tropical and subtropical zones of China. Infection remains a major public health concern despite 45 years of intensive control efforts. It is estimated that 865,000 people and 100,250 bovines are today infected in the provinces where the disease is endemic, and its transmission continues. Unlike the other schistosome species known to infect humans, the oriental schistosome, Schistosoma japonicum, is a true zoonotic organism, with a range of mammalian reservoirs, making control efforts extremely difficult. Clinical features of schistosomiasis range from fever, headache, and lethargy to severe fibro-obstructive pathology leading to portal hypertension, ascites, and hepatosplenomegaly, which can cause premature death. Infected children are stunted and have cognitive defects impairing memory and learning ability. Current control programs are heavily based on community chemotherapy with a single dose of the drug praziquantel, but vaccines (for use in bovines and humans) in combination with other control strategies are needed to make elimination of the disease possible. In this article, we provide an overview of the biology, epidemiology, clinical features, and prospects for control of oriental schistosomiasis in the People's Republic of China.

Observer error and prediction of outcome--grading of head injury based on computerised tomography

OBJECTIVE

To measure inter-observer error of a recently reported computerised tomography scoring system and to assess the ability of the scoring system to predict outcome in head injury patients.

METHODS

Two radiologists independently graded all CT scans performed during the admission of all head injured patients. They were blinded to the clinical condition of the patient. Patients were followed up at 12 months and given a Glasgow outcome score. Outcomes were matched to the 2 independent assessments done on the first CT scan for each patient.

RESULTS

A total of 123 head injury patients were studied. For the diffuse injury categories, there were 410 gradings made. Of these, 32% differed by at least one category. Where at least one of the radiologists identified non-evacuated mass lesions there were 148 gradings. Of these, one radiologist reported an un-evacuated mass lesion in 47%, which was not reported by the other. The first CT scan was evaluated on 119 patients. Using the Chi-Squared test, the diffuse injury IV category was the only one to show a strong relationship with outcome as measured by the Glasgow outcome score.

CONCLUSIONS

The prediction of outcome for head injury patients based on CT scans has significant shortcomings. In our study, there was significant variation in grading by experienced radiologists. The separate categories were also poor predictors of outcome at 12 months except for diffuse injury IV. The classification of mass lesions needs modification to be useful.

Quantifying pulmonary hypertension in ventilated infants with bronchiolitis: a pilot study

OBJECTIVE

To determine whether previously well infants ventilated for bronchiolitis have sufficiently elevated pulmonary artery pressures (PAP) to warrant a trial of inhaled nitric oxide (iNO) therapy.

METHODS

Consecutive infants mechanically ventilated for bronchiolitis were offered Doppler echocardiography between 24 and 72 h after intubation. Patients were divided into those with normal PAP, mild, moderate or severe pulmonary hypertension. Patients with at least moderate pulmonary hypertension (systolic PAP > 30 mmHg and > 50% of systemic systolic arterial pressure) were offered a 60 min trial of iNO therapy at a concentration of 20 ppm and repeat echocardiography.

RESULTS

Six infants (four preterm, two term) were studied at a mean corrected age of 13 weeks (4, 24). Respiratory syncytial virus was confirmed on immunofluorescence of nasal secretions in five of six subjects (84%). Echocardiography was performed (mean, 5.5 days) (95%CI 3.8-7.3) after the onset of symptoms. All patients had structurally normal hearts. Four patients had mild pulmonary artery hypertension and two had normal pulmonary artery pressures. None of the patients qualified for iNO therapy. The mean (range) duration of intubation was 14 days (9-19) and the duration of hospitalization was 28 days (14-42). All patients recovered.

CONCLUSION

Significant pulmonary hypertension should not be presumed in previously well preterm and term infants ventilated for bronchiolitis.

[Preliminary study on cytochrome C oxidase 1 gene of Oncomelania hupensis from Miao River area in Hubei province]

OBJECTIVE

To study the mitochondrial cytochrome C oxidase 1(CO1) gene of Oncomelania snails from Miao River area in Hubei Province.

METHODS

Oncomelania snails were collected from Miao River area, including upstream and downstream. Genomic DNA was extracted from the tissue of the snail. PCR was used to amplify a fragment of the CO1 gene. Sequences of the CO1 fragment were determined directly from the purified PCR products by an automated sequencer. Sequences for each individual were assembled and edited using ESEE 3.0 s. A distance matrix was computed using program DNADISt of PHYLIP(3.57). Unrooted maximum likelihood trees were calculated from program FITCH.

RESULTS

The amplified CO1 gene of the snail was a fragment of 638 bp in length. Sequence analysis showed that the accumulated variable sites were significant different between upstream and downstream populations, being 29 and 46, respectively. From the number of variable sites in the gene, snails in this area were roughly separated into two groups. Each of them was a mixture of both upstream and downstream snails. Same haplotypes were confirmed to be present among the collected sites along the river. From the distance matrix of sequence divergence, the population upstream vs downstream differed by 0.0221 +/- 0.0105.

CONCLUSION

There were more variation in downstream population than that in upstream. Gene flow was identified in these populations. The phylogenetic trees suggest the existence of two groups, but all of them belong to 0. h. hupensis.

The Preschool Respiratory Assessment Measure (PRAM): a responsive index of acute asthma severity

OBJECTIVE

To elaborate and validate a Preschool Respiratory Assessment Measure (PRAM) that would accurately reflect the severity of airway obstruction and the response to treatment in young patients with asthma.

STUDY DESIGN

A prospective cohort study was performed in 217 children aged 3 to 6 years who presented to a pediatric emergency department with acute asthma. Respiratory resistance measured by forced oscillation served as a gold standard. Children were randomized to either the test group, in which multivariate analyses were performed to elaborate the PRAM, or the validation group, in which the characteristics of the PRAM were tested.

RESULTS

For the test group (N = 145), the best multivariate model contained 5 variables: wheezing, air entry, contraction of scalenes, suprasternal retraction, and oxygen saturation. In the validation group (N = 72), the PRAM correlated substantially with the change in resistance (r = 0.58) but modestly with the % predicted resistance measured before (r = 0.22) and after bronchodilation (r = 0.36). A change of 3 (95% CI: 2.2, 3.0) indicated a clinically important change.

CONCLUSIONS

PRAM appears to be a responsive but moderately discriminative tool for assessing acute asthma severity. This measure, designed for preschool-aged children, has been validated against a concurrent measure of lung function.

Oncomelania hupensis (Gastropoda: rissooidea) in eastern China: molecular phylogeny, population structure, and ecology

The rissooidean snail genus Oncomelania is of medical interest as various taxa are hosts for the human blood fluke Schistosoma and the lung fluke Paragonimus; because of close co-evolved host-parasite-relationships, snail diversity may reflect parasite diversity. There is a considerable amount of confusion regarding the identity of smooth- and ribbed-shelled populations of Oncomelania hupensis in eastern China. We therefore studied the genetic variation, population structure, phylogenetic relationships and ecology of five smooth- and five ribbed-shelled populations in Hubei, Hunan, Anhui, Zhejiang, and Jiangsu provinces. Based on sequencing data of a fragment of the mitochondrial gene for cytochrome oxidase I from 80 individuals, we found little genetic variability within the ingroup-individuals studied here (average pi=0.01922). Moreover, within the ingroup, smooth-shelled individuals cluster together with ribbed-shelled individuals. We therefore consider all smooth- and ribbed-shelled populations of Oncomelania throughout the lower Yangtze River basin to belong to the subspecies O. hupensis hupensis. Our data indicate that ribbing in O. h. hupensis is associated with the annual floods of the Yangtze River. The greatest haplotype (d(H)) and nucleotide diversities (pi) are found in aggregates of ribbed-shelled snails along areas of the Yangtze River drainage subject to flooding. In areas not affected by flooding, the shells are smooth and genetic diversity decreases significantly.

Effects of electrical stimulation leg training during the acute phase of spinal cord injury: a pilot study

Four individuals with a spinal cord injury underwent 16 weeks of isometric electrical stimulation training to both legs for 60 min, five times per week during the first 5 months after injury, while two SCI individuals remained untrained. A baseline biopsy sample of the vastus lateralis muscle was obtained within 1 month of injury, and another biopsy sample was taken after a further 16 weeks. The untrained, paralyzed skeletal muscle displayed a reduction in (1) type I fibers (from 50% to 9%), (2) myosin heavy chain (MHC) I (from 27% to 6%), and (3) fiber cross-sectional area of type I, type IIA and type IIX fibers (-62%, -68%, and -55%, respectively) when compared to the baseline sample of muscle taken within 1 month of injury. In contrast, the trained group showed smaller alterations in type I fibers (from 49% to 40%) and MHC I composition (from 39% to 25%), while fiber cross-sectional area was similar to baseline levels for type I, type IIA and type IIX fibers (-3%, -8%, and -4%, respectively). In conclusion, electrical stimulation training can largely prevent the adverse effects of a spinal cord injury upon paralyzed human skeletal muscle if applied soon after the injury.

Dexamethasone for pulmonary interstitial emphysema in preterm infants

The efficacy of a 3-day course of dexamethasone (0.5 mg/kg/ day) in 10 preterm infants (< or = 30 weeks gestation) with pulmonary interstitial emphysema (PIE) was studied in a retrospective case review. PIE was diagnosed at a median age of 7.5 days and treatment with dexamethasone began at 8.5 days. Seven of the 10 subjects had at least 2 days of conservative treatment (lowered mean airway pressure) preceding dexamethasone during which the mean airway pressure (MAP), oxygenation index (OI) and mechanical ventilation index (MVI) were not significantly different although within 3 days of dexamethasone each variable improved significantly (p < 0.05). Similarly, for all 10 infants, OI and MAP were significantly lower at 3 and 7 days from baseline (p < 0.005). By day 7, FiO2 (p = 0.022) and MVI (p = 0.011) were significantly lower and PIE had resolved on chest X-ray in 7/9 (78%) and improved in the remaining 2/9 (22%). Nine of the 10 infants survived to term. Three days of dexamethasone was associated with significant clinical improvement in most of these infants. The mechanism may relate to reduced airway oedema and inflammation and reduced airway obstruction.

Pulmonary outcome in extremely low birth weight infants

OBJECTIVE

To determine whether infants with hyaline membrane disease (HMD) superimposed on immature lung disease (ILD) have more abnormal lung function and respiratory drive during the evolution of chronic neonatal lung disease (CNLD) in extremely low birth weight infants (ELBW; <1000 g).

METHODS

We measured lung mechanics (respiratory frequency, tidal volume, minute ventilation, lung resistance, lung compliance, lung impedance, and work of breathing per minute) and respiratory drive (airway opening pressure 100 milliseconds after initiation of breath [P(0.1)] and maximal inspiratory pressure generated during airway occlusion) on 3 occasions before term in 24 ELBW infants.

RESULTS

Ten infants with ILD (mean [95% CI] gestation: 24.3 weeks [23.1,25.4]; birth weight: 675 g [553,798]) were studied at 27, 31, and 35 weeks of postconceptional age and 14 infants with HMD superimposed on ILD (gestation: 25.1 weeks [24.4,25.9]; birth weight: 687 g [601,773]) were studied at 28, 32, and 35 weeks of postconceptional age. There were no statistically significant differences between the groups for respiratory frequency, tidal volume, minute ventilation, lung resistance, lung compliance, lung impedance, work of breathing per minute, P(0.1), and maximal inspiratory pressure generated during airway occlusion. With increasing age, both groups demonstrated increased respiratory drive as measured by P(0.1) without significant changes in respiratory frequency or CO(2). Work of breathing per minute increased in the HMD group with age and was higher in extubated subjects. A similar trend with age was demonstrated in ILD infants. Regardless of whether the initial lung disease was ILD alone or HMD + ILD, ELBW infants developed a mildly reduced lung compliance/kg (.8-1.1 mL/cm.H(2)O/kg) and high lung resistance (75-125 cm.H(2)O/L/second) pattern of CNLD, which changed little after 3 weeks of age. Survival to 6 months was 23/24 (96%). Oxygen dependency was 16/24 (67%) at 35 weeks, yet only 5/23 (22%) survivors required oxygen at discharge from the neonatal unit (43 weeks).

CONCLUSIONS

The visco-elastic and flow-resistive properties of the lungs in ELBW infants with CNLD remain only mildly abnormal, suggesting a more favorable prognosis for lung function in later years than previously reported.

Treating internal resorption using a syringeable composite resin

BACKGROUND

Internal resorption is a pathological process initiated within the pulp space with the loss of dentin. It often is described as an oval shaped enlargement of the root canal space and usually is asymptomatic and detectable by routine radiographs. Treatment of internal resorption has included several materials--gutta-percha, zinc oxide eugenol and amalgam alloy. These materials do not provide strength to the tooth structure.

CASE DESCRIPTION

A 29-year-old woman was referred to a dental clinic for treatment of a large internal resorptive defect in the coronal and middle one-third of the maxillary left central incisor root with no apparent periapical pathosis, as well as a large periapical radiolucency at the apex of the maxillary left lateral incisor that was associated with a necrotic pulp. The authors used a dual-cure syringable composite resin in conjunction with a bonding agent within the defect to treat it.

CLINICAL IMPLICATIONS

This technique seals the dentinal tubules and strengthens the remaining tooth structure. It also improves the outcome of resorptive defects and reduces operators' chair time.

Erhaia (Gastropoda: Rissooidea): phylogenetic relationships and the question of Paragonimus coevolution in Asia

The human lung fluke Paragonimus is transmitted by gastropod taxa of two superfamilies: Ceritheoidea and Rissooidea. The question whether or not Paragonimus shows the same specificity of host-parasite coevolved relationship as the human blood fluke Schistosoma was inspired by the finding of two sympatric snail species as hosts for Paragonimus skrjabini in Fujian Province, China: Gammatricula and Erhaia. The former species can clearly be classified as Pomatiopsidae: Triculinae. The latter has previously been classified as Pomatiopsidae: Pomatiopsinae. However, this classification based on anatomical characteristics is uncertain. In order to obtain a robust phylogenetic hypothesis for Erhaia, we have studied three gene fragments from this taxon as well as from twelve related taxa. The data show that the species involved represent four families: Pomatiopsidae, Hydrobiidae, Cochliopidae (here raised to family status), and Amnicolidae. Erhaia fits securely into the Amnicolidae. This indicates that P. skrjabini has not coevolved with snail lineages. However, P. skrjabini has so far only been reported from rissooidean snails, whereas members of the Paragonimus westermani complex have only been found in ceritheoidean snails. The implication is that there is a host specificity on the superfamily level. However, Asian freshwater species of the Ceritheoidea and Rissooidea usually are not sympatric and often prefer different habitats. It is therefore possible that ecological niche partitioning plays the primary role for Paragonimus evolution.

Carotid baroreflex control of heart rate and blood pressure during ES leg cycling in paraplegics

This study investigated control of heart rate (HR) and mean arterial pressure (MAP) at rest and during electrical stimulation (ES) leg cycling exercise (LCE) in paraplegics (Para). Seven men with complete spinal lesions (T(5)-T(11)) and six able-bodied (AB) men participated in this study. Beat-to-beat changes in HR and MAP were recorded during carotid sinus perturbation. Carotid baroreflex function curves were derived at rest and during ES-LCE for Para and during voluntary cycling (Vol) for AB. From rest to ES-LCE, oxygen uptake (VO(2)) increased (by 0.43 l/min) and HR rose (by 11 beats/min), yet MAP remained unchanged. In AB, Vol increased VO(2) (by 0.53 l/min), HR (by 22 beats/min), and MAP (by 8 mmHg). ES-LCE did not alter the carotid sinus pressure (CSP)-MAP relationship, but it displaced the CSP-HR relationship upward relative to rest. No rightward shift was observed during ES-LCE. Vol by AB produced an upward and rightward displacement of the CSP-MAP and CSP-HR relationships relative to rest. These findings suggested that the carotid sinus baroreflex was not reset during ES-LCE in Para.

A molecular perspective on the genera Paragonimus Braun, Euparagonimus Chen and Pagumogonimus Chen

The status of the genera Euparagonimus Chen, 1963 and Pagumogonimus Chen, 1963 relative to Paragonimus Braun, 1899 was investigated using DNA sequences from the mitochondrial cytochrome c oxidase subunit I (CO1) gene (partial) and the nuclear ribosomal DNA second internal transcribed spacer (ITS2). In the phylogenetic trees constructed, the genus Pagumogonimus is clearly not monophyletic and therefore not a natural taxon. Indeed, the type species of Pagumogonimus, P. skrjabini from China, is very closely related to Paragonimus miyazakii from Japan. The status of Euparagonimus is less obvious. Euparagonimus cenocopiosus lies distant from other lungflukes included in the analysis. It can be placed as sister to Paragonimus in some analyses and falls within the genus in others. A recently published morphological study placed E. cenocopiosus within the genus Paragonimus and probably this is where it should remain.

Postural control during stance in paraplegia: effects of medially linked versus unlinked knee-ankle-foot orthoses

OBJECTIVE

To investigate the effect of medially linking knee-ankle-foot orthoses (KAFOs) on postural stability and sway during (1) quiet standing and (2) functional activities for persons with spinal cord injury (SCI).

DESIGN

A randomized, mixed design, with the factors being activity (quiet standing and two function-mimicking tasks), SCI (present or not), and type of orthosis used in SCI group (linked or unlinked KAFO).

PARTICIPANTS

Nine men with T5 to T12 paraplegia, 8 of whom had complete lesions and 1 with some sacral sparing (American Spinal Injury Association grade B) without proprioception, matched to 9 able-bodied men.

MAIN OUTCOME MEASURES

Mean amplitude of sway and sway path in anteroposterior and mediolateral directions, derived from center of pressure measurements on a force platform.

RESULTS

All men with SCI were able to stand unsupported and perform function-mimicking activities in medially linked KAFOs; however, when wearing unlinked KAFOs only 5 could maintain balance during quiet stance and 3 could maintain balance during activity. Significant differences were found between linked and unlinked KAFOs; side-to-side mean amplitude of sway was less and sway path was greater for SCI subjects when they wore the linked KAFOs.

CONCLUSION

Medial linkage of bilateral KAFOs provides an effective strategy to improve stability and increase postural control for persons with SCI, facilitating performance of functional activities during standing without upper limb support.

Cardiovascular responses to an orthostatic challenge and electrical-stimulation-induced leg muscle contractions in individuals with paraplegia

The purpose of this study was to investigate the cardiovascular and haemodynamic responses that occur during moderate orthostatic challenge in people with paraplegia, and the effect of electrical stimulation (ES)-induced leg muscle contractions on their responses to orthostatic challenge. Eight males with complete spinal lesions between the 5th and 12th thoracic vertebrae (PARA) and eight able-bodied individuals (AB) volunteered for this study. Changes in heart rate (fc), stroke volume (SV), cardiac output (Qc), mean arterial pressure (MAP), total peripheral resistance (TPR), limb volumes and indices of neural modulation of fc, [parasympathetic (PNS) and sympathetic (SNS) nervous system indicators] were assessed during: (1) supine rest (REST), (2) REST with lower-body negative pressure at -30 torr (LBNP -30, where 1 torr = 133.32 N/m2), and (3) for PARA only, LBNP -30 with ES-induced leg muscle contractions (LBNP + ES). LBNP -30 elicited a decrease in SV (by 23% and 22%), Qc (by 15% and 18%) and the PNS indicator, but an increase in fc (by 10% and 9%), TPR (by 23% and 17%) and calf volume (by 1.51% and 4.04%) in both PARA and AB subjects, respectively. The SNS indicator was increased in the AB group only. Compared to LBNP -30, LBNP + ES increased SV (by 20%) and Qc (by 16%), and decreased TPR (by 12%) in the PARA group. MAP was unchanged from REST during all trials, for both groups. The orthostatic challenge induced by LBNP -30 elicited similar cardiovascular adaptations in PARA and AB subjects. ES-induced muscle contractions during LBNP -30 augmented the cardiovascular responses exhibited by the PARA group, probably via reactivation of the skeletal muscle pump and improved venous return.

Cardiorespiratory responses to arm cranking and electrical stimulation leg cycling in people with paraplegia

PURPOSE

The purpose of this study was to assess the cardiorespiratory responses during arm exercise with and without concurrent electrical stimulation-induced leg cycling in people with paraplegia.

METHODS

On separate days, 10 subjects with spinal cord injuries (T5-T12) performed either arm cranking (ACE), or simultaneous arm cranking + electrical stimulation-induced leg cycling (ACE+ES-LCE) graded exercise tests.

RESULTS

During submaximal, steady-state exercise, ACE+ES-LCE elicited significantly higher VO2, (by 0.25-0.28 L x min(-1)) stroke volume (by 13 mL), and VE(BTPS) (by 9.4 L x min(-1)) compared with ACE alone. In contrast, there were no significant differences of submaximal HR, cardiac output, or power output between the exercise modes. At maximal exercise, ACE+ES-LCE elicited significantly higher VO2 (by 0.23 L x min(-1)) compared with ACE alone, but there were no differences in power output, HR, or VE(BTPS).

CONCLUSIONS

These results demonstrate that during submaximal or maximal exercise there was a greater metabolic stress elicited during ACE+ES-LCE compared with during ACE alone. The higher stroke volume observed during submaximal ACE+ES-LCE, in the absence of any difference in HR, implied a reduced venous pooling and higher cardiac volume loading during ACE+ES-LCE. These results suggest that training incorporating ACE+ES-LCE may be more effective in improving aerobic fitness in people with paraplegia than ACE alone.

Delayed presentation of traumatic arterial vasospasm

Traumatic arterial vasospasm with no surrounding anatomic damage is a rare finding. Delayed presentation of arterial vasospasm several days from the inciting event is also rare. However, when the diagnosis of arterial vasospasm is considered, evaluation and treatment must be initiated promptly to avoid prolonged ischemia to the extremity. We present an 11-year-old female who presented with a delayed presentation of arterial vasospasm, and also review the literature.

A medial linkage orthosis to assist ambulation after spinal cord injury

A "proof of concept" prototype of a new device to link bilateral knee-ankle-foot orthoses, the Mooring Medial Linkage Orthosis (Moorong MLO), is presented. The device consists of an arcuate sliding link centred on the hip joints with rolling element bearings to minimise friction. A single repeated-measures case study is reported in which a woman with an incomplete C6 tetraplegia ambulated over different surfaces and gradients using both the Moorong MLO and the Walkabout orthosis. Results demonstrated a slight increase in gait velocity in the Moorong MLO (between 0.36-1.02 m/min faster) and a consistently lower oxygen cost across all conditions (between 18-61% reduction) compared to the Walkabout orthosis. The reduction was most noticeable on sloping surfaces. These preliminary results suggest an improved efficiency of ambulation in this new device.