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PubMed2003

[Development of automated segmentation method for the posterior portion of the temporal lobe on coronal MR images].

Brain MRI is an important method for examining the diseases caused by various cerebral pathologies, and the measurement of temporal lobe volume is useful for identifying dementia and temporal lobe abnormalities. However, no segmentation algorithm for the temporal lobe on coronal MR images has been established. Such an algorithm is needed because the shape of the temporal lobe on coronal images varies from area to area. The purpose of this research was to develop a segmentation method for the posterior portion of the temporal lobe on coronal MR images. The subjects were 11 normal patients, whose coronal T(1)-weighted images were selected for this study. The preprocessing algorithm for segmentation consists of smoothing, binarization, and thinning. The first step of the segmentation process consists of recognition techniques for the temporal lobe region on thinning images. The next step is distance transformation on identified thinning images. Finally, the temporal lobe was segmented by using the original images and distance transformation images and employing the newly developed algorithm. The rate of accuracy of automated recognition was over 74% for all cases, while the average rate of accuracy was 83.2+/-4.0%. These results suggest that this segmentation method can clearly segment the temporal lobe and has potential for clinical use. Based on this study, although it included only 11 normal patients, we have started applying this segmentation method to many patients, with or without temporal lobe disease.

Adult↗
PubMed1999

Electric birefringence of recombinant spectrin segments 14, 14-15, 14-16, and 14-17 from Drosophila alpha-spectrin.

Members of the spectrin protein family can be found in many different cells and organisms. In all cases studied, the major functional role of these proteins is believed to be structural rather than enzymatic. All spectrin proteins are highly elongated and consist mainly of homologous repeats that constitute rigid segments connected in tandem. It is commonly believed that the details of the spectrin function depend critically on the flexibility of the links between the segments. Here we report on a work addressing this question by studying the transient electric birefringence of recombinant spectrin fragments consisting of segments 14, 14-15, 14-16, and 14-17, respectively, from Drosophila alpha-spectrin. Transient electric birefringence depends sharply on both molecular length and flexibility. We found that the birefringence relaxation time of segment 14 measured at 4 degrees C, but scaled to what is expected at 20 degrees C, equals 16 ns (+/-15%) at pH 7.5 and ionic strength 6 mM. This is consistent with this single segment being rigid, 5 nm long and having an axial ratio equal to about two. Under the same conditions, segments 14-15, 14-16 and 14-17 show relaxation times of 45, 39 and 164 ns (all +/-20%), respectively, scaled to what is expected at 20 degrees C. When the temperature is increased to 37 degrees C the main relaxation time for each of these multisegment fragments, scaled to what is expected at 20 degrees C, increased to 46, 80, and 229 ns (all +/-20%), respectively. When the ionic strength and the Debye shielding is low, the dynamics of these short fragments even at physiological temperature is nearly the same as for fully extended weakly bending rods with the same lengths and axial ratios. When the ionic strength is increased to 85 mM, the main relaxation time for each of these multisegment fragments is reduced 20-50% which suggests that at physiological salt and temperature conditions the links in 2-4-segment-long fragments exhibit significant thermally induced flexing. Provided that the recombinant spectrin fragments can serve as a model for native spectrin, this implies that, at physiological conditions, the overall conformational dynamics of a native spectrin protein containing 20-40 segments equals that of a flexible polymer.

Animals↗
PubMed1999

Cell lineage analysis of pattern formation in the Tubifex embryo. I. Segmentation in the mesoderm.

Annelids are strongly segmented animals that display a high degree of metamerism in their body plan. The embryonic origin of metameric segmentation was examined in an oligochaete annelid Tubifex using lineage tracers. Segmental organization arises sequentially in the anterior-to-posterior direction along the longitudinal axis of the mesodermal germ band, a coherent column of primary blast cells that are produced from the mesodermal teloblast. Shortly after its birth, each primary blast cell undergoes a spatiotemporally stereotyped sequence of cell divisions to generate three classes of cells (in terms of cell size), which together give rise to a distinct cell cluster. Each cluster is composed of descendants of a single primary blast cell; there is no intermingling of cells between adjacent clusters. Relatively small-sized cells in each cluster become localized at its periphery, and they form coelomic walls including an intersegmental septum to establish individuality of segments. A set of cell ablation experiments showed that these features of mesodermal segmentation are not affected by the absence of the overlying ectodermal germ band. These results suggest that each primary blast cell serves as a founder cell of each mesodermal segment and that the boundary between segments is determined autonomously. It is concluded that the metameric body plan of Tubifex arises from an initially simple organization (i.e., a linear series) of segmental founder cells.

Animals↗
PubMed1999

[Segmentation in vertebrates: a molecular clock linked to periodic somite formation].

In the vertebrate embryo, somites constitute the basis of the segmental body pattern. They give rise to the axial skeleton, the dermis of the back and all striated muscles of the body. In the chick embryo, a pair of somites buds off, in a highly coordinated fashion, every 90 minutes, from the cranial end of the presomitic mesoderm (PSM) while new mesenchymal cells enter the paraxial mesoderm as a consequence of gastrulation. The processes leading to the segmentation of the somite are not yet understood. We have identified and characterised c-hairy1, an avian homologue of the Drosophila segmentation gene, hairy. c-hairy1 is strongly expressed in the presomitic mesoderm where its mRNA exhibits a cyclic posterior-to-anterior wave of expression whose periodicity corresponds to the formation time of one somite (90 min). Fate mapping of the rostral half of the PSM using the quail-chick chimera technique supports a model of cryptic segmentation within the presomitic mesoderm, and indicates that c-hairy1 expression dynamics are not due to massive cell displacement. Analysis of in vitro cultures of isolated presomitic mesoderm demonstrates that rhythmic c-hairy1 mRNA production and degradation is an autonomous property of the paraxial mesoderm. Rather than resulting from the caudal-to-rostral propagation of an activating signal, it arises from pulses of c-hairy1 expression that are coordinated in time and space. Blocking protein synthesis does not alter the propagation of c-hairy1 expression, indicating that negative autoregulation of c-hairy1 expression is unlikely to control its periodic expression. Most of the segmentation models proposed for somite formation rely on the existence of an internal clock coordinating the cells to segment together to form a somite. These results provide the first molecular evidence of a developmental clock linked to segmentation and somitogenesis of the paraxial mesoderm, and support the possibility that segmentation mechanisms used by invertebrates and vertebrates have been conserved.

Animals↗
PubMed2001

[A contour map segmentation for laser scanning confocal microscopic biomedical images].

We propose a contour map segmentation method for laser scanning confocal microscopic (LSCM) biomedical images. In this method, an image is first segmented into sub-regions by contour map. Then the sub-regions are merged from top to bottom or from bottom to top, according to a segmentation criterion of intensity homogeneity. The merging procedures continue until no region needs to be merged. The advantage of this method is that the objects with wide intensity ranges and different intensity homogeneity can be segmented properly. In this paper, the region segmentation by contour map is first addressed. Next a region merging according to a segmentation criterion of intensity homogeneity is presented, and then the design of a linear intensity homogeneity segmentation criterion is introduced. Two examples of image segmentation by this method are given at the end of this paper.

Algorithms↗
PubMed2002

Screw placement of pedicle of vertebral arch--pay great attention to segmental differences of the pedicle.

OBJECTIVE: To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane. METHODS: Fifteen preserved thoracolumbar spine specimens (T(11)-L(5)) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy-camille, Magerl, and authors' segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed. RESULTS: Four anatomic parameters at various segments showed significant differences (P<0.05). The drilling point by the Roy-camille's method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E-angles of the pedicles. The drilling point by Magerl's method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E-angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy-camille's method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws were used. CONCLUSIONS: The segmental difference method is proved to have the anatomic safety and screw biomechanical stability. It is appropriate to choose different diametral screws, different drilling points and directions according to different segments of the vertebra.

Adult↗
PubMed2003

Distinction between myocardial ischemia and postural changes in continuous ECG monitoring based on ST-segment amplitude and vector orientation--preliminary results.

BACKGROUND: Myocardial ischemia, commonly defined as ST-segment elevation or depression on the electrocardiogram (ECG), is plagued by a large number of false positive events. OBJECTIVES: To present a new method that attempts to distinguish between 'highly probable ischemia' and positional changes. METHODS: Continuous three-lead orthogonal ECG monitoring was performed in three groups of subjects: 16 healthy volunteers undergoing a body position change protocol, 22 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) and 17 patients with acute coronary syndromes (ACS). For each event (ischemic or postural), the change in ST-segment amplitude was calculated, as well as the angle between the ST-segment vector of the reference beat and the beats demonstrating ST-segment elevation or depression. Angles and ST-segment amplitude changes from well-documented ischemic events obtained from the PTCA patients and from the healthy volunteers in six different body positions were compared. RESULTS: Using both ST-segment amplitude and vector angle changes, ischemic events could be detected and differentiated from a postural change with a sensitivity of 91% and a specificity of 96%. Finally, the approach was blindly applied to continuous ECG recordings of ACS patients. The method allowed the classification of 37% of all ST-segment changes detected as highly probable ischemic events as opposed to only 7% using the standard 100 microV threshold. CONCLUSION: The current approach showed that highly probable ischemic events could be better distinguished from positional changes with objective criteria using ST-segment amplitude and vector orientation.

Adult↗
PubMed2003

[Binding between alpha 1A-adrenergic receptor and segment of bone morphogenetic protein-1 in human embryonic cell 293].

Using matchmaker yeast two-hybrid system, it has been demonstrated that there exists an interaction between the cellular C terminal of alpha(1A)-adrenergic receptor (alpha(1A)-AR) and a segment of bone morphogenetic protein-1 (BMP-1). In the present study binding between the two proteins was further determined in human embryonic cell 293 (HEK293), a mammalian expression system. Mammalian expression vector PCP3HA was constructed by PCR and consisted of segments of BMP-1 cDNA, and vector PDT-alpha(1A) consisted of the full-length cDNA of human alpha(1A)-AR. They were transfected to HEK293 cells and examined by Western blot. alpha(1A)-AR and the segment of BMP-1 could be detected in the lysis of transfected cells. Then binding between alpha(1A)-AR and the segment of BMP-1 in HEK293 cell was determined by enzyme-linked immunosorbent assays (ELISA) and co-immunoprecipitation. In ELISA experiment, the ELISA microwell plate was first coated with anti-FLAG M2 antibody, which recognizes the FLAG-tagged alpha(1A)-AR, then the cell lysis, anti-HA rabbit polyclonal antibody and HRP conjugated anti-rabbit antibody were added in turn. The OD(490) values among the control group, PDT-alpha(1A) transfection group and PCP3HA transfection group, exhibited no significant difference (0.034+/-0.027, 0.042+/-0.019, 0.030+/-0.0096), but the OD(490) values of PDT-alpha(1A) and PCP3HA co-transfection group (0.57+/-0.12) were significantly higher than those of the other groups (P<0.001, respectively). In co-immunoprecipitation experiments, HEK293 cells expressing alpha(1A)-AR or/and segment of BMP-1 were lysed and incubated with anti-FLAG M2 antibody, then the immunoprecipitation pellet was immunoblotted with either the HRP conjugated anti-FLAG antibody or the anti-HA antibody, which recognizes the HA-tagged segment of BMP-1. Segment of BMP-1 was present in the pellet immunoprecipitation of PDT-alpha(1A) and PCP3HA co-transfected group. In conclusion, the results indicate that alpha(1A)-AR and the segment of BMP-1 are present in the same complex in HEK293 cells.

Adrenergic alpha-Agonists↗
PubMed2004

Normalisation of elevated ST segment predicts return of left ventricular systolic function and improved outcome in patients with acute myocardial infarction, treated with primary coronary angioplasty.

BACKGROUND: It has been shown that normalisation of elevated ST segment after primary percutaneous coronary interventions (PCI) is associated with the achievement of reperfusion at the tissue level. AIM: To assess prospectively the return of left ventricular (LV) systolic function and the outcome of patients with acute myocardial infarction (AMI), treated with primary PCI, in relation to the early normalisation of the ST segment. METHODS: The study group consisted of 110 consecutive patients (33 females, 77 males, mean age 56 years) with AMI who were successfully treated with primary PCI (TIMI flow grade 3 and residual stenosis <30%) within 12 hours from the onset of symptoms. The patients were divided into two groups according to normalisation or lack of normalisation of an elevated ST segment. The mean time from the onset of symptoms to the restoration of blood flow in an infarct-related artery (pain-to-balloon time) was similar in both groups. LV echocardiographic parameters (ejection fraction EF and wall motion score index WMSI) and clinical status directly after PCI as well as 3 and 6 months later were assessed. RESULTS: Directly after primary PCI, LV impairment (low EF and high WMSI) was significantly more often present in patients without rather than with ST segment normalisation. Afterwards, LVEF and WMSI improved significantly only in patients with ST segment normalisation whereas in the remaining patients no such improvement was observed. During 6-month follow-up period, major cardiac events (death, new AMI or need for revascularisation) occurred more frequently in patients without rather than with ST segment normalisation (p=0.03). CONCLUSIONS: 1. Rapid resolution of ST segment elevation following effective primary PCI identifies patients with a favourable outcome. 2. ST segment normalisation predicts a return of LV systolic function in patients with AMI treated with primary PCI.

Aged↗
PubMed2004

[Malnutrition detected by "bioelectrical status" of total and segmental body mass to nutritional management of patients].

We examined 182 controls with Body Mass Index (BMI) between 20 and 25 kg/m2 and 246 hospitalised patients divided into 3 groups: the first one consisted of 70 severe malnourished with (BMI) < 20 kg/m2, the second one of 43 light malnourished with BMI between 20 and 25 kg/m2 and the last one of 133 obese with BMI > 25 kg/m2. The Resistance (Rs) and Reactance (Xc), with the Phase angle ((phi), are detected from total and segmental (Arm and "Trunk + Leg") body. We analysed electric parameters plotting them on 4 different graphs which reported the values of: 1) total Rs vs total Xc; 2) segmental Rs vs segmental Xc; 3) total Rs/height vs weight/ height; 4) total Xc/height vs weight/height. Rs and Xc were different in all groups: the severe malnourished patients (1st group) gave evidence of a paradoxical increase of Rs and a decrease of phi. The mean values decreased for the patient of the 2nd and 3rd group (the (phi reduced especially for the 2nd group). Referring to the segmental measures, "Trunk + Leg" biases total Rs and Xc much more than Arm. In addition the phi of "Trunk + Leg" is more similar to the total o than the Arm one. If compared with the total, this last one highly decreases in the patients of the 1st and 2nd group. We conclude that segmental bioelectrical values (Rs, Xc, phi) integrate the total one, because they allow to find out the correlation between total parameters and a specific body segment. Total and segmental Rs, Xc (and phi) values and segmental phi ratio are related to the malnutrition. The approach together with the analysis of the Graphics result to a prompt inspection of the individual bioelectrical status in subjects.

Algorithms↗
PubMed2005

Identification of the segmental artery feeding the anterior spinal artery: correlation between helical CT and angiography.

PURPOSE: We investigated whether identification of the segmental artery feeding the anterior spinal artery (ASA) is possible by single-slice helical CT. MATERIAL AND METHODS: Enhanced CT and angiography were performed in 14 patients with retroperitoneal, liver, or bone tumor. A single-slice helical CT scanner with 7 mm collimation and a 1.0 helical pitch was used. Scanning was started 25 to 30 sec after an intravenous injection of 100 ml of contrast medium at a rate of 3.0 ml/sec. RESULTS: We predicted the segmental artery feeding the ASA in all 14 patients using enhanced CT images. In 12 of the 14 patients, the segmental artery feeding the ASA was angiographically identified. In 7 of these 12 patients, the level of the segmental artery feeding the ASA identified on segmental arteriogram was the same level as that predicted by enhanced CT. In the remaining 5 patients, the level of the segmental artery feeding the ASA identified on segmental arteriogram was one level higher or lower than the predicted spinal level. CONCLUSION: We could identify the segmental artery feeding the ASA by detailed examination and interpretation of single-slice helical CT images.

Adult↗
PubMed1992

[Surgical stress stimulates release of polymorphonuclear leukocyte elastase from a segmented neutrophil].

The studies were performed to find out whether increased serum levels of polymorphonuclear leukocyte elastase (PMNE) depend on increase of segmented neutrophils or increase of PMNE release from a segmented neutrophil on 17 patients for various elective surgeries. Serum levels of PMNE, leukocyte count and leukogram were determined before incision (preoperation), as well as on the 1st, 3rd and 5th day after operation. Serum levels of PMNE, segmented cell count, stab cell count, stab cell-segmented cell ratio increased most on the 1st postoperative day and decreased thereafter. Leukocyte count showed no significant changes. Serum levels of PMNE correlated well with PMNE released from a segmented neutrophil, but not with leukocyte count or segmented cell count. It was concluded that increased serum levels of PMNE by surgical stress depend on the increased PMNE release from a segmented neutrophil but not on the increased segmented cell count.

Adult↗
PubMed2006

3-D brain segmentation towards the integration of DTI and MRI modalities.

This study introduces a 3-D segmentation method together with a graphical user interface (GUI) as means to effectively automate the process of segmentation with the ultimate objective of integrating and visualizing diffusion tensor imaging (DTI) with magnetic resonance imaging (MRI) in a fully automated 3-D brain imaging system. A secondary objective is to reduce significantly the segmentation time required to extract key landmarks of the brain in contrast to the manual process currently used at many hospital settings. The results provided will prove this important assertion. The inter-correlation coefficient revealed 96.1% accuracy in segmenting all of the processed data, which consequently led to effective registration of the DTI and MRI modalities since they involve the same landmarks. The average speed of segmentation was just 35 seconds, a reduction of over 20 times of what is required for manual segmentation. In order to create a highly integrated interface, the segmentation results serve as input to a registration algorithm we are currently investigating and whose preliminary results support the significance of relying on an effective segmentation process. T1-weighted 3D Gradient Echo MR and DT images from 16 patients at Miami Children's Hospital were used for evaluation purposes.

Algorithms↗
PubMed1990

Diagnostic complementary DNA probes for genome segments 2 and 3 of epizootic hemorrhagic disease virus serotype 1.

Potential diagnostic complementary DNA (cDNA) clones of gene segments 2 and 3 from epizootic hemorrhagic disease virus serotype 1 (EHDV-1) have been produced. Individual segments of EHDV-1 were isolated, denatured with methylmercury hydroxide, and polyadenylated. The polyadenylated RNA was reverse-transcribed and self-hybridized into duplex structures, and the incomplete ends were repaired. The resulting product was then cloned into the plasmid vector pBR322, using the complementary tailing method. Two clones, 1 from segment 2 (E1-2-10) and 1 from segment 3 (E1-3-16) were isolated, colony-purified, and characterized by cDNA/RNA blot hybridization and endonuclease restriction analysis. The cDNA clones of RNA segment 3 of EHDV-1 cross hybridized with the corresponding segment of EHDV serotype 2 by results of cDNA/RNA blot hybridization, but not with RNA of bluetongue virus serotypes isolated in the United States. After cDNA/RNA dot-blot hybridization analysis of 17 EHDV field strains, the segment-2 clone was found to be serotype-specific, whereas the segment-3 clone was serogroup-specific.

Animals↗
PubMed1979

Innervation of the canine inferior vena cava. Distribution of adrenergic and cholinergic excitatory fibers among the embryologically distinct segments.

The innervation of three embryologically distinct segments of the canine inferior vena cava was investigated. These segments were termed A (supradiaphragm), B-C (intrahepatic and that between liver and renal veins), and D (infrarenal). Strips were cut from these segments, and their isometric tensions were recorded. Transmural electrical stimulation induced contractile responses in circular strips from segment B-C (66.5% of the maximum norepinephrine-induced response) and in those from D (14.4%), but not in A. These responses almost completely disappeared in the presence of phenoxybenzamine. In segment B-C, however, the remaining small contraction was markedly enhanced by neostigmine and abolished by atropine. The same phenomenon was also observed in the contraction remaining after reserpinization. Longitudinal strips from segment C responded similarly. Concentration-response curves of circular strips for acetylcholine were shifted by neostigmine markedly to the left only in segment B-C, while no significant shift occurred in A and D. It was concluded that the adrenergic innervation is remarkably dense in B-C, sparse in D, and probably lacking in A. In addition, a cholinergic excitatory innervation is present in segment B-C.

Acetylcholine↗
PubMed1989

The reverse of intestinal segments for the treatment of ileostomy diarrhea.

Ileostomy diarrhea still represents a real problem; for further understanding of it's management using Anti-Peristaltic Segments we have undertaken an experimental study where 12 mongrel dogs were used. Permanent ileostomy was done after which segments of small intestine of different lengths 5-55 cm long were divided 35 cm proximal to the ileostomy and rotated on their vascular pedicle through 180 degrees, and continuity of the small intestine was restored. Quality, quality of the stool, intestinal transit time, body weight loss, and survival of the experimental animals were studied to observe the effect of Anti-Peristaltic Intestinal Segments, the length of the Anti-Peristaltic segments needed for better control of ileostomy diarrhea, and the Critical length of the Anti-Peristaltic segments. We have observed that dogs cannot tolerate ileostomy. Anti-Peristaltic Intestinal Segments regulate the quality and quantity of stools, delay the intestinal transit, allow for the greater absorption and decrease the weight loss, but only to certain limits. Anti-Peristaltic intestinal segments of 20-30 cm. long give better control of ileostomy diarrhea. The critical Anti-Peristaltic intestinal segment is 50 cm long.

Anastomosis, Surgical↗
PubMedDate not supplied

[Behavior of the ST segment, during isometric exercise, in chagasic patients with apical aneurysm of the left ventricle].

In order to study the ST-segment changes during isometric exercise (IE) we have reviewed the hemodynamic and cineangiographic protocols of 13 with Chaga's disease patients. On the basis of the electrocardiogram (EKG) and the left ventricular cineangiogram, the chagasic patients were divided in two groups. Chagas' group I: 6 patients with left ventricular apical aneurysm, Chagas' II: 7 patients with multiple left ventricular dyskinetic segment and occasional premature ventricular contractions. Fourteen subjects with normal left ventricular cineangiograms and normal EKG's were used as controls. The IE was performed by all chagasic and control subjects 31.9 +/- 18 (M +/- SD) months after the cardiac catheterization. The IE was performed at 25% of maximum voluntary capacity for 5 minutes. The precordial leads (V1-V6) were simultaneously recorded, in the standing position, immediately before and after the IE. The ST-segment changes were assessed by measuring the distance of the 'J point, of the ST-segment, to the baseline in three consecutive sinus beats. Immediately before the IE, 5 patients of Chagas' group I (86%) has ST-segment elevation (leadas V1-V2). In the control group, only 2 subjects (14%) had ST-segment elevation, (P less than 0.007). After IE, the control subjects "normalized" their ST-segment elevation, whereas it persisted elevated in the 5 Chagas' group I patients (P less than 0.003). These results suggest that in chagasic patients, the ST-segment changes observed during isometric exercise could be related to the presence of left ventricular apical aneurysm.

Adult↗
PubMed1989

Direct lymphatic drainage of lung segments to the mediastinal nodes. An anatomic study on 260 adults.

The subpleural lymphatics of 483 lung segments were injected in cadavers of 260 adult subjects. The injected lymph vessels corresponded to the pulmonary segmentation in 91% of the cases and remained close by in the other cases. Direct passages to the mediastinal nodes were observed in 54 of 243 right lung segments injected (22.2%) and 60 of 240 left lung segments (25%). Among a total of 114 direct passages observed, 99 remained superficial in the pleura, half of them composed of a single vessel. These passages have been observed more frequently in the segments of the upper lobes. Injections of basal segments in the right and left lower lobes showed fewer of these direct passages to the mediastinal lymph nodes and also demonstrated direct lymph vessels to lymph nodes located at the origin of the upper lobar bronchi. In two dissections of the right upper lobe, the drainage went directly to the right venous jugular-subclavian junction, and in three dissections from three right terminal basal segments the lymph vessel went directly to the thoracic duct in its mediastinal passage. Direct contralateral lymph pathways were observed five times, four of them from basal segments of lower lobes.

Adult↗