Craniocaudal Gradient Research Articles

Differences in lung attenuation gradients between supine and standing positions in healthy participants on conventional/supine and upright computed tomography

The effect of gravity on the lungs has been evaluated using computed tomography (CT) in the supine and prone positions but not the standing position. However, as humans spend most of the daytime in the standing position, we aimed to compare lung attenuation gradients between the supine and standing positions, and to assess the correlations between the lung attenuation gradients and participant characteristics, including pulmonary function test results. Overall, 100 healthy participants underwent conventional/supine and upright CT, and lung attenuation gradients were measured. Lung attenuation gradients in anteroposterior direction were greater in the supine position than in standing position (all p values < 0.0001) in both upper lobes at the level of the aortic arch (right: standing/supine, -0.02 ± 0.19/0.53 ± 0.21; left: standing/supine, -0.06 ± 0.20/0.51 ± 0.21); in the right middle (standing/supine, -0.26 ± 0.41/0.53 ± 0.39), left upper (standing/supine, -0.35 ± 0.50/0.66 ± 0.54), and lower lobes at the level of the inferior pulmonary vein (right: standing/supine, -0.22 ± 0.30/0.65 ± 0.41; left: standing/supine, -0.16 ± 0.25/0.73 ± 0.54); and in both lower lobes just above the diaphragm (right: standing/supine, -0.13 ± 0.22/0.52 ± 0.32; left: standing/supine, -0.30 ± 0.57/0.55 ± 0.37). Craniocaudal gradients were greater in the standing position (right: standing/supine, 0.41 ± 0.30/0.00 ± 0.16; left: standing/supine, 0.35 ± 0.30/-0.02 ± 0.16, all p values < 0.0001). No moderate to very high correlations were observed between age, sex, height, weight, body index mass, or pulmonary function test results and each lung attenuation gradient. Lung attenuation gradients in anteroposterior direction, which was observed in the supine position, disappeared in the standing position. However, the craniocaudal lung attenuation gradient, which was not present in the supine position, appeared in the standing position.

Three-dimensional micromorphology of human midpalatal suture and pterygomaxillary articular complex.

Sutures exist in the craniofacial area, and the pattern of maturation and synostosis of facial sutures is largely unknown. For a comprehensive understanding of the three-dimensional circummaxillary suture micromorphology, human midpalatal suture (MPS) and pterygomaxillary articular complex from eight subjects' (five males, three females, 72-88 years old) autopsies were longitudinally scanned with microcomputed tomography. Additional histology was performed for hematoxylin and eosin staining. Sutural micromorphology was assessed by interdigitation index (II), obliteration index (OI) and obliteration number. Intergroup comparisons were performed with Kruskal-Wallis and Mann-Whitney U with Bonferroni correction (α=0.005). Correlation with anteroposterior and craniocaudal gradients was assessed with Spearman's correlation test (α=0.05). Maxillary region of MPS presented a higher II 1.50 (0.61) and obliteration number per slice 8 (9) (P < 0.005). OI was increased in palatomaxillary 35% (47%) followed by pterygopalatine suture 25% (49%) (P < 0.005). The II and OI of the MPS exhibited only a weak anteroposterior gradient, with relatively low correlations. Obliteration areas were found sporadically along the entire MPS. Based on these findings, it is conceivable that the success of nonsurgical maxillary expansion largely depends on individual variations in sutural morphology and maturation rather than appliance design.

Mapping the medullar adiposity of lumbar spine in MRI: A feasibility study

PurposeThe bone medullar adiposity is a marker of bone quality to the point that there is a need to investigate the factors which influence or not the density and distribution of this fat in the spine, especially at the lumbar level. The purpose was to test the feasibility of a Dixon three-point technique and investigate the vertebral marrow fat distribution. Material and methodsA sagittal sequence Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-squares Estimation (IDEAL) IQ was performed on the lumbar spine of 46 subjects who were not suffering from any bone disease (21 women and 25 men, aged 18–77 years). Medulla adiposity was determined directly from the measurement of the fat fraction in each vertebral body (T12 to S1) obtained on the fat cartography automatically generated by the IDEAL sequence. ResultsAverage vertebral fat fraction was 36.48% (SD 12.82), with a tendency to increase with age and to higher values among men. We observed a craniocaudal gradient of the fat fraction (β = 1.37; p < 0,001; SD 0.11) increasing with age in the lumbar spine from T12 to L5. Through multivariate analysis, this gradient was adjusted for sex, weight and height of the subjects. ConclusionThis feasibility study shows the existence of a physiological craniocaudal gradient of vertebral medullar adiposity from T12 to L5. This gradient increases with age but it is independent of sex or BMI. The IDEAL sequence allows quick and reproducible measurement of the spine vertebral medullar adiposity.

Increasing Warmth in Adolescents with Anorexia Nervosa: A Randomized Controlled Crossover Trial Examining the Efficacy of Mustard and Ginger Footbaths.

Objective To analyze the thermogenic effects of footbaths with medicinal powders in adolescents with anorexia nervosa (AN) in comparison to healthy controls (HCs). Intervention and Outcomes. Forty-one female participants (21 AN, 20 HCs; 14.22 ± 1.54 years) received three footbaths—warm water and mustard (MU, Sinapis nigra), warm water and ginger (GI, Zingiber officinale), or warm water only (WA), in random order within a crossover design. Data were collected before (t1), immediately after foot immersion (maximum 20 minutes) (t2), and after 10 minutes subsequently (t3). Actual skin temperature (high resolution thermography) and perceived warmth (HeWEF questionnaire) were assessed at each time point for various body parts. The primary outcome measure was self-perceived warmth at the feet at t3. Secondary outcome measures were objective skin temperature and subjective warmth at the face, hands, and feet. Results Perceived warmth at the feet at t3 was significantly higher after GI compared to WA (mean difference −1.02) and MU (−1.07), with no differences between those with AN and HC (−0.29). For the secondary outcome measures, a craniocaudal temperature gradient for the skin temperature (thermography) was noted at t1 for patients with AN and HC (AN with colder feet). The craniocaudal gradient for subjective warmth was only seen for patients with AN. Conclusion Footbaths with ginger increased warmth perception at the feet longer than with mustard or warm water only for adolescents with AN as well as for HC. The impact of ginger footbaths on recovery of thermoregulatory disturbances in patients with AN repeated over extended periods merits further investigation.

Histostructure of the Locomotor Apparatus in the Three Deep-Water Species of Lanternfishes (Myctophidae): Myctophum punctatum, Notoscopelus kroyeri, and Lampanyctus macdonaldi

The morphological and functional characteristics of the somatic musculature’s histological structure have been studied for three species of deep-sea fish from the Myctophidae family: spotted lanternfish Myctophum punctatum, lancet fish Notoscopelus kroyeri, and rakery beaconlamp Lampanyctus macdonaldi. The average diameter of fast-twitch and slow-twitch muscle fibers in all studied species is large, and this indicator is highest in rakery beaconlamp. All species are characterized by a craniocaudal gradient of a decrease in the size of white muscle fibers. The shape of the fibers, from angular polygonal (spotted lanternfish) to the oval (rakery beaconlamp) and round (lancet fish), is a distinctive feature from other species of bony fish. In spotted lanternfish, a group of fibers of very small diameter, which are presumably small, slow-twitch oxidizing fibers, was also noted between the white and red muscles. The red muscles in the studied fish are poorly identified, since they are poorly developed. The studied species have a well-developed connective tissue carcass of white muscles, which indicates a certain friability of fast-twitch muscles. Both the red and white muscles in lanternfishes are a place of intense deposition of lipid reserves. Apparently, the high lipid content in muscle tissue helps to reduce the specific gravity of fish and increase their buoyancy.

Компьютерная томография в диагностике различных форм амиодарон-индуцированной легочной токсичности

Purpose: To determine computed tomography subtypes of amiodarone-induced pulmonary toxicity (AIPT). &#x0D; Material and methods: We included 214 CT exams of 110 patients with history of amiodarone use. AIPT was confirmed in 90 cases. In 81 % of patients we repeat CT exam 2–5 times, observation period till 1 month to 10 years. The mean age of patients was 71 years (21 females, 69 – males). In 52 % of patients lung scintigraphy was done. We included functional lung test, spirometry, heart ultrasound in diagnostic plan.&#x0D; Results: Only in 3 % of cases we detected acute form of AIPT. In 68 % of patients subacute form was revealed, in that cases we indentified different patterns of lung defeat, which mimic oncology disease, different types of interstitial pneumonias, small vessel pulmonary embolism. In other cases chronic form AIPT was suspected. Unilateral changes and craniocaudal gradient were not pathognomic for AIPT. We did not identify consolidation zones and nodules. Honeycombing was not a typical feature of chronic form of AIPT. Appearance of ground-glass opacity pattern was feature of lung toxicity exaxerbation.&#x0D; Conclusion: AIPT diagnose of exclusion because of it’s multiple radiological subtypes. There are no specific histological or cytological markers of the disease. Only CT could identify signs of active process and differentiate different subtypes of AIPT.

Difference in the craniocaudal gradient of the maximum pixel value change rate between chronic obstructive pulmonary disease patients and normal subjects using sub-mGy dynamic chest radiography with a flat panel detector system

ObjectivesTo compare the craniocaudal gradients of the maximum pixel value change rate (MPCR) during tidal breathing between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. Materials and methodsThis prospective study was approved by the institutional review board and all participants provided written informed consent. Forty-three COPD patients (mean age, 71.6±8.7 years) and 47 normal subjects (non-smoker healthy volunteers) (mean age, 54.8±9.8 years) underwent sequential chest radiographs during tidal breathing in a standing position using dynamic chest radiography with a flat panel detector system. We evaluated the craniocaudal gradient of MPCR. The results were analyzed using an unpaired t-test and the Tukey–Kramer method. ResultsThe craniocaudal gradients of MPCR in COPD patients were significantly lower than those in normal subjects (right inspiratory phase, 75.5±48.1 vs. 108.9±42.0s−1cm−1, P<0.001; right expiratory phase, 66.4±40.6 vs. 89.8±31.6s−1cm−1, P=0.003; left inspiratory phase, 75.5±48.2 vs. 108.2±47.2s−1cm−1, P=0.002; left expiratory phase, 60.9±38.2 vs. 84.3±29.5s−1cm−1, P=0.002). No significant differences in height, weight, or BMI were observed between COPD and normal groups. In the sub-analysis, the gradients in severe COPD patients (global initiative for chronic obstructive lung disease [GOLD] 3 or 4, n=26) were significantly lower than those in mild COPD patients (GOLD 1 or 2, n=17) for both right and left inspiratory/expiratory phases (all P≤0.005). ConclusionsA decrease of the craniocaudal gradient of MPCR was observed in COPD patients. The craniocaudal gradient was lower in severe COPD patients than in mild COPD patients.

Neuropathological criteria of anti-IgLON5-related tauopathy.

We recently reported a novel neurological syndrome characterized by a unique NREM and REM parasomnia with sleep apnea and stridor, accompanied by bulbar dysfunction and specific association with antibodies against the neuronal cell-adhesion protein IgLON5. All patients had the HLA-DRB1*1001 and HLA-DQB1*0501 alleles. Neuropathological findings in two patients revealed a novel tauopathy restricted to neurons and predominantly involving the hypothalamus and tegmentum of the brainstem. The aim of the current study is to describe the neuropathological features of the anti-IgLON5 syndrome and to provide diagnostic levels of certainty based on the presence of associated clinical and immunological data. The brains of six patients were examined and the features required for the neuropathological diagnosis were established by consensus. Additional clinical and immunological criteria were used to define “definite”, “probable” and “possible” diagnostic categories. The brains of all patients showed remarkably similar features consistent with a neurodegenerative disease with neuronal loss and gliosis and absence of inflammatory infiltrates. The most relevant finding was the neuronal accumulation of hyperphosphorylated tau composed of both three-repeat (3R) and four-repeat (4R) tau isoforms, preferentially involving the hypothalamus, and more severely the tegmental nuclei of the brainstem with a cranio-caudal gradient of severity until the upper cervical cord. A “definite” diagnosis of anti-IgLON5-related tauopathy is established when these neuropathological features are present along with the detection of serum or CSF IgLON5 antibodies. When the antibody status is unknown, a “probable” diagnosis requires neuropathological findings along with a compatible clinical history or confirmation of possession of HLA-DRB1*1001 and HLA-DQB1*0501 alleles. A “possible” diagnosis should be considered in cases with compatible neuropathology but without information about a relevant clinical presentation and immunological status. These criteria should help to identify undiagnosed cases among archival tissue, and will assist future clinicopathological studies of this novel disorder.Electronic supplementary materialThe online version of this article (doi:10.1007/s00401-016-1591-8) contains supplementary material, which is available to authorized users.

Fast Helical Tomotherapy in a head and neck cancer planning study: is time priceless?

BackgroundThe last few years, in radiotherapy there has been a growing focus on speed of treatment delivery (largely driven by economical and commercial interests). This study investigates the influence of treatment time on plan quality for helical tomotherapy (HT), using delivery times with Volumetric Modulated Arc Therapy (VMAT; Rapid Arc [RA]) as reference.MethodsIn a previous study, double arc RA (Eclipse) and standard HT plans (TomoHD™) were created for five oropharyngeal cancer patients and reported according to ICRU 83 guidelines. By modifying the beam width from 2.5 to 5.0 cm, elevating the pitch and lowering the modulation factor, “TomoFast” (TF) plans were generated with treatment times equal to RA plans. To quantify the impact of TF’s craniocaudal gradient, similar plans were generated on TomoEdgeTM (TomoEdgeFast;TEF). The homogeneity index (HI), conformity index (CI), mean dose, Dnear-max (D2) and Dnear-min (D98) of the PTVs were analyzed as well as the mean dose, specific critical doses and volumes of 26 organs at risk (OARs). Data were analyzed using repeated measures ANOVA.ResultsWith a mean treatment time of 3.05 min (RA), 2.89 min (TF) and 2.95 min (TEF), PTVtherapeutic coverage was more homogeneous with TF (HI.07;SE.01) and TEF (HI.08;SE.01) compared to RA (HI.10;SE.01), while PTVprophylactic was most homogeneous with RA. Mean doses to parotid glands were comparable for RA, TF, TEF: 25.62, 25.34, 23.09 Gy for contralateral and 32.02, 31.96, 30.01 Gy for ipsilateral glands, respectively. OARs’ mean doses varied between different approaches not favoring a particular technique. TF’s higher dose to OARs at the cranial-caudal edges of the PTVs and its higher integral dose, both due to the extended cranial-caudal gradient, seems to be solved by the new TomoEdge™ software. However, all these faster techniques lose part of standard TomoHD’s OAR sparing capacityConclusionIt is possible to treat oropharyngeal cancer patients using HT (TF/TEF) within time-frames observed for RA maintaining comparable target coverage and sparing of OARs. This study indicates that treatment time is not technology specific, rather an operator’s decision on balancing efficiency and quality.

Multiple organ involvement by alpha‐synuclein pathology in Lewy body disorders

Lewy body (LB) diseases are characterized by alpha-synuclein (AS) aggregates in the central nervous system (CNS). Involvement of the peripheral autonomic nervous system (pANS) is increasingly recognized, although less studied. The aim of this study was to systematically analyze the distribution and severity of AS pathology in the CNS and pANS. Detailed postmortem histopathological study of brain and peripheral tissues from 28 brain bank donors (10 with Parkinson's disease [PD], 5 with dementia with LB [DLB], and 13 with non-LB diseases including atypical parkinsonism and non-LB dementia). AS aggregates were found in the pANS of all 15 LB disease cases (PD, DLB) in stellate and sympathetic ganglia (100%), vagus nerve (86.7%), gastrointestinal tract (86.7%), adrenal gland and/or surrounding fat (53.3%), heart (100%), and genitourinary tract (13.3%), as well as in 1 case of incidental Lewy body disease (iLBD). A craniocaudal gradient of AS burden in sympathetic chain and gastrointestinal tract was observed. DLB cases showed higher amounts of CNS AS aggregates than PD cases, but this was not the case in the pANS. No pANS AS aggregates were detected in Alzheimer's disease (AD) cases with or without CNS AS aggregates. All pathologically confirmed LB disease cases including 1 case of iLBD had AS aggregates in the pANS with a craniocaudal gradient of pathology burden in sympathetic chain and gastrointestinal tract. AS was not detected in the pANS of any AD case. These findings may help in the search of peripheral AS aggregates in vivo for the early diagnosis of PD.

Brain size and white matter content of cerebrospinal tracts determine the upper cervical cord area: evidence from structural brain MRI

Measurement of the upper cervical cord area (UCCA) from brain MRI may be an effective way to quantify spinal cord involvement in neurological disorders such as multiple sclerosis. However, knowledge on the determinants of UCCA in healthy controls (HCs) is limited. In two cohorts of 133 and 285 HCs, we studied the influence of different demographic, body-related, and brain-related parameters on UCCA by simple and partial correlation analyses as well as by voxel-based morphometry (VBM) across both cerebral gray matter (GM) and white matter (WM). First, we confirmed the known but moderate effect of age on UCCA in the older cohort. Second, we studied the correlation of UCCA with sex, body height, and total intracranial volume (TIV). TIV was the only variable that correlated significantly with UCCA after correction for the other variables. Third, we studied the correlation of UCCA with brain-related parameters. Brain volume correlated stronger with UCCA than TIV. Both volumes of the brain tissue compartments GM and WM correlated with UCCA significantly. WM volume explained variance of UCCA after correction for GM volume, whilst the opposite was not observed. Correspondingly, VBM did not yield any brain region, whose GM content correlated significantly with UCCA, whilst cerebral WM content of cerebrospinal tracts strongly correlated with UCCA. This latter effect increased along a craniocaudal gradient. UCCA is mainly determined by brain volume as well as by WM content of cerebrospinal tracts.

Gubernaculum as icebreaker: do matrix metalloproteinases in rodent gubernaculum and inguinal fat pad permit testicular descent?

Purpose Cryptorchidism is the most common male congenital abnormality. The rodent gubernaculum steers the testis from abdomen to scrotum postnatally by eversion and migration through the developing inguinal fat pad (IFP). We hypothesize that extracellular matrix remodeling in/around the gubernaculum is necessary for eversion and migration and is permitted by timed IFP maturation and aimed to examine regional development and matrix metalloproteinase (MMP) content. Methods Embryonic day 19 (E19) and postnatal days 0 and 2 (P0, P2) wild-type Sprague-Dawley rats (n = 10) were prepared for histologic examination (trichrome) and immunohistochemistry (membrane-type MMP-1 [MT1-MMP], MMP2) and analyzed using light/confocal microscopy. Results At E19, IFP contained fibroblasts and immature cells in an extensive collagenous extracellular matrix. Cells in the gubernaculum base were cytoplasmic-MT1-MMP-positive (inactive). At P0, the gubernaculum had everted, and adjacent cells were membranous-MT1-MMP-positive (active). At P2, the gubernaculum was migrating through the IFP, and adjacent cells were membranous-MT1-MMP-positive. Adipocyte maturation began cranially in the IFP and proceeded in a craniocaudal gradient until more uniformly mature at P2. Conclusion The MT1-MMP-positive cells may remodel the gubernaculum for eversion and provide the collagenolysis necessary for migration, like an icebreaking ship, through the IFP, which matures to permit migration through collagen-rich tissue. Disruption of these processes may cause cryptorchidism.

Pisa syndrome in Parkinson's disease: Clinical, electromyographic, and radiological characterization

Abnormal postures of the trunk are a typical feature of Parkinson's disease (PD). These include Pisa syndrome (PS), a tonic lateral flexion of the trunk associated with slight rotation along the sagittal plane. In this study we describe clinical, electromyographic (EMG), and radiological features of PS in a group of 20 PD patients. All patients with trunk deviation underwent EMG and radiological (RX and CT scan) investigation. Clinical characteristics of patients with PS were compared with a control group of PD patients without trunk deviation. PD patients with PS showed a significantly higher score of disease asymmetry compared with the control group. In the majority of patients with PS, trunk bending was contralateral to the side of symptom onset. EMG showed abnormal tonic hyperactivity on the side of the deviation in the paravertebral thoracic muscles and in the abdominal oblique muscles. CT of the lumbar paraspinal muscles showed muscular atrophy more marked on the side of the deviation, with a craniocaudal gradient. PS may represent a complication of advanced PD in a subgroup of patients who show more marked asymmetry of disease and who have detectable hyperactivity of the dorsal paravertebral muscles on the less affected side. This postural abnormality deserves attention and proper early treatment to prevent comorbidities and pain.

Maladie de Niemann-Pick de type B révélée par une atteinte bronchopulmonaire

Niemann Pick disease type B (NPD type B) is a rare autosomal recessive lipid storage disorder, characterized by a partial deficiency of sphingomyelinase. We report the case of an adult male patient affected by NPD type B and diagnosed at 39-years-of age. Pulmonary CT scan revealed a cranio-caudal gradient with nodular centrilobular ground glass opacities and thickening of the interlobular septa. Pathological examination of the bronchoalveolar lavage showed foamy alveolar macrophages and vacuolated bronchial epithelial cells on bronchial biopsy. Diagnostic confirmation was achieved by a decrease in cell lysosomal enzyme activity and by the presence of the homozygous DeltaR608 mutation in the acid sphingomyelinase gene (SMPD1).

Intrathecal baclofen therapy for neurological disorders: a sound knowledge base but many challenges remain

Continuous infusion of intrathecal baclofen (ITB) via a subcutaneously implanted pump has developed over the last 20 years as a powerful tool in the management of spasticity in various adult and paediatric neurological conditions. Acting more focally on spinal GABA receptors, ITB causes fewer systemic side effects than orally administered baclofen. The result is facilitation of daily caring, and symptomatic relief from painful spasm. With increasing experience of ITB use, novel applications and indications are emerging. These include the management of dystonia and chronic neuropathic pain. However, despite some recent authoritative reviews, there is still uncertainty about optimal use and evaluation of this therapy. Many challenges remain. How can efficacy of therapy best be assessed both at primary testing and after pump implantation? What is the precise mechanism of baclofen action in different brain and spinal disorders associated with spasticity and dystonia? Does placement of the spinal catheter tip influence efficacy? What is the cranio-caudal gradient of CSF baclofen levels at given pump flow rates and does this matter? What CSF baclofen levels are efficacious in various conditions? Why do some patients with the same primary condition require large differences in ITB dose? What are the relative merits of programmable versus constant infusion rate pumps? What are the implications of setting up multidisciplinary teams for long term follow up? This review evaluates these questions and highlights other areas for further investigation.

Sonic hedgehog in avian branchial arch development

Sonic hedgehog (Shh) is involved in development of many embryonic structures. This study tries assess requirement for Shh to mediate normal branchial and aortic arch development. Shh is expressed among others in the pharyngeal endoderm from st. 17. Its expression coincides with branchial arch formation, which occurs in a temporal craniocaudal gradient starting at st. 11. In embryos treated with cyclopamine, a compound that blocks the Shh response, branchial arches were reduced in form, invaded with phagocytic cells and heads of embryos were often malformed. The aortic arches form, however, their lumen, visualized with the QH1 antibody, was misshapen and sinusoidal. Injection of 5E1 hybridoma cells, which produce an antibody that blocks Shh signaling by sequestration of the ligand, has a more profound effect on branchial arch development than cyclopamine. Capillary plexus formation was inhibited, and a higher number of QH1 positive cells in the arch mesenchyme (hemangioblasts and macrophage-like cells) were observed. Numerous apoptotic cells were found in the mesenchyme, while phagocytic cells were present in meso-, ecto- and endoderm. Our observations indicate requirement for Shh signaling for branchial morphogenesis as well as cell survival in the aortic and branchial arches. Supported by MSM 0021620806; GAUK 54/203209; 1R01HD042307(NIGMS)

Biogenic amines and pterins in cerebrospinal fluid: some pitfalls with interpretation

The quantification of neurotransmitters or their metabolites in cerebrospinal fluid (CSF) can provide valuable clues for the detection of (often treatable) genetic disorders or their biosynthesis or salvage pathways. These analyses are technically demanding since the concentrations to be assessed are in the nanomolar range. To date, only a few laboratories worldwide offer these analyses. Since some metabolites are unstable at room temperature and sensitive to light or oxygen, special preparation of sampling tubes is helpful and the samples should be immediately frozen at the bedside. Furthermore, due to a craniocaudal gradient, a sampling protocol with numbered tubes should be adhered to. In addition to the technical difficulties, interpretation of the biochemical findings in lumbar CSF is much more complex than the interpretation of results in urine or blood. This article will focus on some pitfalls associated with the interpretation of analyses of dopamine, serotonin and pterin metabolites, and examines clinical data from pediatric patients to further illustrate those pitfalls.

The Importance of Being Asymmetric: The Physiology of Digesta Propulsion on Earth and in Space

In the embryo, the mammalian gastrointestinal tract (GIT) is a midline structure, but later becomes strikingly asymmetric. Such asymmetry is in contrast to other organ systems that are essentially bilaterally symmetric. Making a departure from the traditional straight tube model of the bowel, we offer a more realistic model-a kinked collapsible conduit disposed as a constrained kinematic chain. We examine evidence for the importance of its asymmetry to the unidirectional flow of digesta. A number of factors cooperate to ensure a unidirectional flow. The anatomical factors must include (1) the shape of the abdomen, the inverted truncated cone allowing several degrees of freedom of movement of the bowel allowing folds and twists; (2) the location of the liver and the stomach under the diaphragm, providing for efficient force transmission from the diaphragm (especially in the distended state in the case of the stomach); (3) cranio-caudal gradients in length of the small bowel mesentery and diameter of the bowel lumen. The physiological factors include (1) a deliberate conversion of ingested food into a non-Newtonian fluid with increasing viscosity, (2) nonlinearity of the tube law, (3) respiratory excursions of the diaphragm, and (4) a "Law of the Intestine". In microgravity, the bowel can be expected to float and exhibit loss of polarity of propulsion of digesta, but this can be compensated for by exercise (indirectly by increasing diaphragmatic movement). The asymmetry of the GIT is an ingenious device to ensure a unidirectional movement of digesta.

Productivity of Cinta Senese and Large White x Cinta Senese pigs reared outdoors in woodlands and indoors. 2. Slaughter and carcass traits

The aim of this paper was to study slaughter and carcass traits of Cinta Senese pigs, both pure and crossbred with Large White, reared outdoors in woodland and indoors. Sixteen Cinta Senese (CS) and 16 Large White x Cinta Senese (LWxCS) pigs were reared outdoors (OUT) on woodland pastures with some food supplementation; 70 animals (29 CS, 29 LWxCS and 12 LW) were reared indoors (IN), allotted in pens for genetic type and sex. Pigs were slaughtered at about 140 kg of live weight and at an age greater than 8 months. After slaughter, carcass length, thorax depth, number of vertebrae and backfat thickness were measured, and carcasses were dissected into lean, fat and bone cuts. Average daily gain to slaughter differed markedly among the five GTxRS combinations (598; 512; 438; 338; 250 g/d, respectively for LW-IN; LWxCS-IN; CS-IN; LWxCS-OUT; CS-OUT). LWxCS-IN and LWxCS-OUT had respectively the highest and the lowest dressing percentages (83.3% and 80.1%). A greater compactness of CS carcasses was evident from the length to depth ratio. In both farming systems CS pigs had the thickest backfat, and their differences with the other genetic types increased proportionally according to a cranio-caudal gradient. Moreover, CS pigs showed lower percentage of lean cuts and a higher percentage of fat cuts, than the other breeds. In the indoor system an additive effect was evident, with crossbred pigs showing lean cuts yields (62.8%) of almost intermediate value with respect to the parental breeds (57.7% for CS and 69.1% for LW). Some effects of the availability of woodland pastures on growth and carcass composition were also observed, particularly showing CS-OUT pigs’ higher percentage of backfat and kidney fat, and lower percentage of loin and shoulder than the CS-IN ones.

Distribution of Lung Density and Mass in Patients With Emphysema as Assessed by Quantitative Analysis of CT

To assess the effects of emphysema on the apex-to-base gradient of lung density (D) and lung mass (M) and to explore the relationship between M and lung function. CT scans of whole lungs were performed in 12 healthy subjects and 29 patients who were breathing at functional residual capacity, after which lung function tests were performed. Whole D and M and regional D (RLD) and M (RLM) were calculated. The degree of emphysema was scored. The RLM for each height did not differ significantly between patients with disease and healthy subjects, while RLD was significantly lower in the patients with disease. A less marked nonlinear, increasing, craniocaudal gradient of D was observed in the group with disease, suggesting that the distension increases progressively from the apex to the base. RLD and RLM in the 40 to 90% lung height differed significantly among patients in the emphysema group with normal, high, and low M compared to the healthy subjects. M did not differ significantly between patients with centrilobular and panlobular emphysema, which was thought to stem from the marked variations in the results. Vital capacity was lower in the patients with low M. The lower RLD in the group with low M was due to both lung overinflation and to tissue loss, while in the groups with high or normal M, it was due only to lung overinflation.