A simplified method for metabolic studies in conscious swine

Reliable short-term blood access in conscious swine was provided by implanting multiple silastic catheters. Catheters were inserted into the aorta, hepatic vein, portal vein, and inferior vena cava through a midline laparotomy incision. Multiple catheters also were placed into the external jugular vein through a separate cervical incision. Catheter patency rates for blood withdrawal on the sixth post-operative day were: arterial 100%, hepatic 91%, portal 86%, inferior vena cava 71%. No animal had major wound or catheter infection on the seventh post-operative day. The methods described allow metabolic studies, including measurements of splanchnic blood flow, to be carried out either acutely or for up to at least 7 days post-operatively.     

Removal of abdominal sources of caudal mediastinal node lymph in anesthetized sheep

We investigated the conditions for and the quantity of abdominal contributions to caudal mediastinal node (CMN) efferent lymph in 15 anesthetized sheep with open thorax and lung lymph fistulas. Contractions of the diaphragm by phrenic nerve stimulation increased lymph flow by 29%. Adding large volumes (10 ml/kg) of 5% albumin solution to the peritoneal cavity increased lymph flow by 19 and 28% during diaphragm contraction. Tracer albumin specific activity in lymph indicated that about half the lymph flow increment came from the peritoneal liquid. Raising hepatic vein pressure 19 cmH2O increased CMN lymph flow 178%. Lymph protein concentration also increased markedly, from 0.72 to 0.91 of the plasma concentration. We devised a simple procedure to cauterize across the pleural surface of the diaphragm to destroy the aberrant lymphatics. This procedure markedly diminished both abdominal cavity and portal system contributions.     

Plasma progesterone concentration depends on sampling site in pigs

The objective of this study was to examine a possible difference in progesterone concentrations between the systemic venous blood and the caudal vena cava in early pregnant gilts. Nineteen crossbred pregnant gilts were offered three different regimens of feeding to examine influence of feeding on the secretion pattern of progesterone. The groups were high (H-H), low (L-L) and low-high (L-H) receiving 3.6, 1.8 and 1.8/3.6 kg/day, respectively. Catheters were placed in a jugular vein and the caudal vena cava (to sample ovarian secretion) on day 19 of pregnancy. Two consecutive samples taken at 30-min intervals were collected four times a day for 5 days (days 20-24). In addition, three gilts were simultaneously sampled from both catheters at 30-min intervals for 12 h on day 22. Progesterone concentration was significantly lower in the jugular vein compared with the caudal vena cava in all three feeding groups (P<0.001). An indication of episodic pattern of progesterone production occurred in plasma collected from the caudal vena cava, but not from the jugular vein. Dietary intake did not cause a profound effect on plasma progesterone concentrations during days 20-24 of gestation. It seemed that ovarian progesterone was released into the vena cava in an episodic pattern and there were implications that these episodes were temporally associated with LH pulses.     

Morphofunctional reorganization of the kidneys in lymphatic outflow disturbance

In 115 Wistar male rats structures and rates of tissue blood flow have been studied in the cortical and medullary renal substance histologically, polarographically (estimation of the volumetric tissue blood flow by hydrogen clearance). Systemic arterial (peritoneal aorta), venous (caudal vena cava) and lymphatic (renal lymph nodes) pressures have been measured, normal and after ligation of the thoracic duct at early (1-3 days), middle (1 month) and late (2-3 months) periods. In 1-3 days edema and dystrophy of the renal parenchyma, decrease of the blood flow rate in the cortical and its increase in the renal medullary substance, as well as a sharp elevation of pressure in the lymph nodes are observed. In 1 month of the experiment together with dystrophy and edema moderate sclerosis, decreasing blood flow rate in the cortical and medullary substance are noted. Increase of the systemic arterial and venous pressure and decreasing pressure in the lymph nodes, as well as a sharp increase of the renal nodes mass are revealed. In 2-3 months of the experiment, together with sclerosis of the renal parenchyma, elevated blood flow rate is observed in the kidneys and decreasing pressure in the lymph nodes up to its initial value takes place.     

Trichinella spiralis: newborn larval migration route in rats reexamined

The route by which Trichinella spiralis newborn larvae migrate from the small intestine to striated muscle was studied in inbred AO and random-bred Sprague-Dawley rats. Newborn larvae were quantitatively recovered from the thoracic duct lymph, peritoneal cavity, and hepatic portal vein blood during the course of a primary infection with 4000 muscle larvae. The total recovery of newborn larvae assessed in this manner was compared with the number of muscle larvae in control rats receiving the same infection. In both strains of rats, most of the newborn larvae were recovered from hepatic portal vein blood, fewer than 3% of newborn larvae were recovered from the thoracic duct lymph and peritoneal cavity combined. Long-term drainage of thoracic duct lymph (greater than 24 hr) significantly increased newborn larval recovery over short-term drainage (less than 24 hr). We conclude that there are several natural pathways of newborn larval migration that result in muscle larval establishment. These include direct invasion of capillaries and lymphatics in the intestine as well as migration through the intestinal serosa to the peritoneal cavity. In both AO and Sprague-Dawley rats, greater than or equal to 97% of newborn larvae migrate via the hepatic portal vein blood to the general circulation.     

Anomalous caudal vena cava passing through the vertebral canal in a calf

A 15-day-old female Holstein-Friesian calf with an anomalous caudal vena cava was examined macroscopically, roentgenologically, and histologically. The calf, weighing 43 kg, had severe scoliosis. A common renal vein merged into a single venous trunk formed by the union of the left and right common iliac veins. The trunk entered the vertebral canal through the left intervertebral foramen formed by the last (13th) thoracic and the first lumbar vertebrae. The trunk continued along the ventral side of the narrowing spinal cord inside the canal, and then ran out the left intervertebral foramen formed by the 8th and 9th thoracic vertebrae and emptied via the right azygos vein into the cranial vena cava. In contrast, the hepatic vein passed through the foramen vena cava independently of the trunk and entered the right atrium directly. The pathogenesis of the present anomaly may be explained as follows: The right subcardinal vein, failing to make connection with the liver, shunted directly into the right azygos vein derived from the right supracardinal vein. The body axis began to curve before ossification of the vertebrae occurred. Consequently, the developing right supracardinal vein, located close to the spinal cord, is thought to have become enclosed in the vertebrae with the spinal cord during the early fetal stages.     

Evidence for a migratory capability of rat Kupffer cells to portal tracts and hepatic lymph nodes

The present study concerns the migratory ability of Kupffer cells in the rat. Phagocytic cells were labeled with colloidal carbon or gold, these markers being administered intravenously either into a tail vein, which resulted in generalized reticuloendothelial uptake, or in low dose into the portal vein, which produced uptake by Kupffer cells alone. Cells containing marker were observed in the portal tracts and in hepatic lymph nodes from 1 to 3 days after injection into the portal vein. The direct movement of single marker particles to the portal tracts could be excluded. Since injection of marker into the portal vein labeled Kupffer cells exclusively, whereas blood cells, splenic and bone marrow macrophages remained unlabeled, the labeled cells in the portal tracts and hepatic lymph nodes appeared to be former Kupffer cells migrating which had migrated to these sites.     

Problems associated with the measurement of mean circulatory filling pressure by the atrial balloon technique in anaesthetized rats.

To examine the existence of pressure equilibrium between tributary veins and the central vena cava during the mean circulatory filling pressure manoeuvre, pressures in the hepatic portal vein, renal vein, and inferior vena cava were determined at 4-s intervals over a 20-s period of circulatory arrest induced by inflating a right atrial balloon in normal blood volume, 10% volume depletion, and 10% volume expansion states in urethane-anaesthetized rats. Portal vein pressure determined 8 s after arrest during volume depletion and expansion was significantly higher than vena caval pressure (6.2 +/- 0.8 vs. 3.4 +/- 0.2 and 7.7 +/- 0.5 vs. 6.2 +/- 0.4 mmHg (1 mmHg = 133.32 Pa), respectively; p less than 0.01); this pressure disequilibrium continued for 16 s during volume expansion and for the entire 20 s during volume depletion. Renal vein pressure was equal to vena caval pressure during this manoeuvre. Portal vein pressure at normal blood volume was not significantly different from vena caval pressure following circulatory arrest (4.6 +/- 0.3 vs. 3.8 +/- 0.4 mmHg, respectively). Following ganglionic blockade, portal vein pressure was still significantly higher than vena caval pressure for 12 s during volume alterations. At the 8th s of the arrest the portal pressure determined in volume depletion was 3.6 +/- 0.3 mmHg and the inferior vena caval pressure was 2.6 +/- 0.4 mmHg (p less than 0.05). Under the volume expansion condition, the respective values were 6.5 +/- 0.3 and 5.3 +/- 0.4 mmHg (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Trichinella spiralis: vascular recirculation and organ retention of newborn larvae in rats

The recirculation of Trichinella spiralis newborn larvae was studied in inbred AO rats. Newborn larvae collected after in vitro incubation of adult T. spiralis worms for 2 or 24 hr were injected into rats through the tail vein or hepatic portal vein. Blood samples from the femoral vein, hepatic portal vein, and abdominal aorta were collected at intervals from 1 min to 24 hr after larval injection. Newborn larvae of both ages (24 hr or 2 hr old) persisted in femoral vein blood for less than or equal to 5 hr after injection, but they could be detected in portal vein blood by 24 hr after injection. The injection of larvae into a tail vein or the portal vein did not influence the pattern of larval circulation, although there was a 1-5 min delay in newborn larval appearance time after injection into the portal vein. Transcapillary migration through tissue and back to the circulation was evident in the appearance of newborn larvae in the thoracic duct lymph up to 24 (occasionally 48) hr after tail vein injection of newborn larvae. During the course of a natural primary infection, no evidence for trapping of larvae in the mesenteric lymph node could be found despite direct larval migration through this organ. Injected newborn larvae were retained in the lungs, and small numbers could be recovered 24 hr after intravenous injection. We conclude that a proportion of newborn larvae recirculates within the vasculature for several hours; a smaller population extravasates but can reenter the circulatory system via the lymphatics. Furthermore, some newborn larvae are found in organs rich in capillaries up to 24 hr after their entry into the blood.     

环颈雉胃的血供

用血管铸型法和大体解剖学方法对环颈雉胃动脉的起源、分布及胃静脉的回流情况进行了解剖学研究。结果表明,环颈雉的胃动脉均由腹腔动脉分出;腺胃由腺胃背侧动脉和腺胃腹侧动脉营养,腺胃背侧动脉直接起自腹腔动态的左侧,腺胃腹侧动脉起自腹腔动脉左支。腺胃血液的静脉有腺胃前静脉和腺胃后静脉,分别汇入后腔静脉和左肝门静脉。肌胃由肌胃左动脉、肌胃右动脉和肌胃背侧动脉营养,肌胃左动脉起自腹腔动脉的左支;肌胃右动脉起自腹腔动脉的右支;肌胃背侧动脉从腺胃背动脉分支而来。回流肌胃血液的静脉有胃右静脉、胃左静脉和胃腹侧静脉;胃右静脉汇入右肝门静脉,胃左静脉和胃腹侧静脉汇入左肝门静脉。另外腺胃和肌胃的表面缺乏主干动脉间的吻合。     

A Canine Model for IVC Occlusive Form of Budd–Chiari Syndrome Using Endovascular Technique

The objective of this study was to assess the portal/hepatic changes in a newly designed canine model for Budd–Chiari syndrome (BCS). The inferior vena cava (IVC) was occluded using a diagram stent under general anesthesia in 10 mongrel dogs under the guidance of percutaneous angiography. Five dogs that received IVC angiography only were used as sham controls. Occlusion of the IVC increased the diameter of the hepatic veins, portal vein, and IVC. Massive ascites, significantly increased abdominal circumference, varying degrees of esophageal varices, congestion, cirrhosis, and fibrosis of the liver were also noted. BCS could be readily established by placing a diaphragm–stent in the IVC via a percutaneous endovascular approach.     

A Case of Budd-Chiari Syndrome Associated with Alveolar Echinococcosis

Although alveolar echinococcosis (AE) can cause a serious disease with high mortality and morbidity similar to malign neoplasms. A 62-year-old woman admitted to a hospital located in Sivas, Turkey, with the complaints of fatigue and right upper abdominal pain. On contrast abdominal CT, a 54×70×45 mm sized cystic lesion was detected in the left lobe of the liver that was seen to extend to the posterior mediastinum and invade the diaphragm, esophagus, and pericardium. The cystic lesion was seen to be occluding the inferior vena cava and left hepatic vein at the level where the hepatic veins poured into the inferior vena cava. Bilateral pleural effusion was also detected. We discussed this secondary Budd-Chiari Syndrome (BCS) case, resulting from the AE occlusion of the left hepatic vein and inferior vena cava, in light of the information in literature.     

Autologous perfusion of an isolated rabbit gastrointestinal tract.

Most perfusion techniques rely on mechanical means to provide blood flow to the isolated organ for maintaining its physiological conditions. The approach usually requires a complicated mechanical system with the associated problems of blood type matching and prevention of blood cell damage. This paper describes a gastrointestinal tract perfusion technique that uses the rabbit's own cardiopulmonary system as the autologous blood supply source. The technique allows for the removal of the complete intestinal loop from the abdominal cavity of the rabbit, and maintains its blood circulation through silastic tubing connections of the catheterized portal vein and cranial and caudal mesenteric arteries. An alternative perfusion site that uses the aorta as the arterial blood supply and the vena cava as the venous return also is described. The isolated perfused GI tract may then be placed in a separate test environment for controlled experiments. For an acute animal test, the approach was found to be a convenient alternative to conventional approaches.     

The localization of CD3, CD79a,CD68 and S100 protein immunoreactive cells in hemal nodes of Saanen goat (Capra hircus)

We investigated the structure of hemal nodes in Saanen goats using immunohistochemical staining. We examined the distribution of CD3 positive T lymphocytes, CD79a positive B lymphocytes, CD68 positive macrophages and S100 protein positive follicular dendritic cells. Hemal nodes of six healty adult female goats were used. Hemal nodes were removed from the thoracic and abdominal cavities. The oval to round hemal nodes were observed especially between the abdominal aorta and vena cava, and near the kidneys and adrenal glands. Tissue sections were stained with Crossmon’s modified triple stain to demonstrate general histological structure. The avidin-biotin-peroxidase technique using anti-CD3, anti-CD79a, anti-CD68 and anti-S100 primary antibodies was used for immunohistochemistry. Many CD3 positive T lymphocytes were found in the germinal center of the lymph follicles and in the lymphatic cords of hemal nodes; CD3 positive cells also were observed in the sinuses. CD79a and CD68 positive cells were found at the germinal center of the lymph follicles. In the lymph follicles near the subcapsular sinuses, CD79a and CD68 positive cells were found especially in e areas bordering the mantle zone. S100 positive cells were found in the lymph follicles, lymphatic cords and sinuses.     

Intravascular pressure profiles in elephant seals: hypotheses on the caval sphincter, extradural vein and venous return to the heart

In order to evaluate hemodynamics in the complex vascular system of phocid seals, intravascular pressure profiles were measured during periods of rest-associated apnea in young elephant seals (Mirounga angustirostris). There were no significant differences between apneic and eupneic mean arterial pressures. During apnea, venous pressure profiles (pulmonary artery, thoracic portion of the vena cava (thoracic vena cava), extradural vein, and hepatic sinus) demonstrated only minor, transient fluctuations. During eupnea, all venous pressure profiles were dominated by respiratory fluctuations. During inspiration, pressures in the thoracic vena cava and extradural vein decreased -9 to -21 mm Hg, and -9 to -17 mm Hg, respectively. In contrast, hepatic sinus pressure increased 2-6 mm Hg during inspiration. Nearly constant hepatic sinus and intrathoracic vascular pressure profiles during the breath-hold period are consistent with incomplete constriction of the caval sphincter during these rest-associated apneas. During eupnea, negative inspiratory intravascular pressures in the chest ("the respiratory pump") should augment venous return via both the venae cavae and the extradural vein. It is hypothesized that, in addition to the venae cavae, the prominent para-caval venous system of phocid seals (i.e., the extradural vein) is necessary to allow adequate venous return for maintenance of high cardiac outputs and blood pressure during eupnea.     

Secretion of progesterone during long and short days of the estrous cycle in goats that are continuous breeders

This study was conducted 1) to determine if the secretion of progesterone, as an index of ovarian activity, during the estrous cycle of nonseasonal Shiba goats is affected by seasonal changes, and 2) to learn if the pulsatile secretion of ovarian progesterone can be estimated from samples obtained by cannulation into the caudal vena cava via the femoral vein. Progesterone concentrations in jugular venous plasma during the estrous cycle in spring (May) were similar to those in autumn (November). Plasma progesterone concentrations in the jugular vein and caudal vena cava monitored for 10 h on Day 12 of the estrous cycle in spring were similar to those in autumn. The mean concentration (21.9 to 28.9 ng/ml) and the pulse frequency (6.2 to 7.4 pulses/10 h) of plasma progesterone in the caudal vena cava during both seasons were 3.1- to 4.7-fold and 1.7- to 2.4-fold those in the jugular vein, respectively. The degree of change in the peak magnitude and the base-line concentration of progesterone were higher in the caudal vena cava than in the jugular vein. These results indicate that progesterone secretion during the estrous cycle in nonseasonal goats is not affected by seasonal changes, and suggest that the pulsatile secretion of ovarian progesterone can be evaluated better from samples obtained from the caudal vena cava, near where progesterone is released, than from those obtained from the jugular vein.     

Computed tomography of the thorax in rabbits: a prospective study in ten clinically healthy New Zealand White rabbits

Background

Literature investigating the normal cross-sectional anatomy of rabbits with computed tomography (CT) is sparse and incomplete. The purpose of the present study was to investigate the normal thoracic structures, in particular the cranial thorax, with CT angiography in 10 clinically healthy New Zealand White (NZW) rabbits.

Results

Absolute and relative measurements of the trachea, heart, thoracic caudal vena cava and aorta, right and left principal bronchi, right and left caudal lobar bronchi and the accompanying branches of the right and left pulmonary artery and vein, right and left lung volume and lung density were taken. The three lobes of the thymus (right ventral, right dorsal and left thoracic lobes) were identified in all rabbits. Both the right dorsal and left thoracic lobes of the thymus extended between the heart and thoracic wall in all individuals with the left lobe reaching more caudally in seven animals. Consequently, the craniocaudal extension of the left lung was smaller than the right lung in these rabbits. Volume of the left lung was significantly smaller than the right (P = 0.005). The cranial mediastinal, right and left tracheobronchial and the aortic thoracic lymph nodes were very small and identified in four, four, seven and ten rabbits, respectively. The heart took up a median of 4.0 intercostal spaces, and in seven rabbits, it was located in the 2nd–5th intercostal space. Median relative cardiac height and width measured 74 and 88%, respectively. The median angle of the trachea to the spine was 5°. Median density between the right and left lung did not significantly differ (? 549 and ? 583 Hounsfield units, respectively). In all but one rabbit, atelectasis was present and classified as mild, moderate or severe in six, two and one individuals, respectively. Mild subclinical bronchopneumonia was diagnosed in seven rabbits.

Conclusions

The present study provides species-specific anatomical CT information and reference values for structures in the thorax of the NZW rabbit. Subclinical bronchopneumonia appears to be a common CT finding.

     

Comparative study of the changes in microanatomical organization of lymph nodes located and functioning in the area of venous congestion

By the morphometric method the microanatomical organization of the popliteal and kidney lymph nodes of the type Vi was studied in venous congestion. In the first experimental series (lymph nodes localize in venous congestion area) the venous congestion in the popliteal lymph nodes was created by the ligature of caudal vena cava. In the second experimental series (lymph nodes, which clean the venous congestion area--the kidney vena was tied up. The small and short time increase of the marginal sinus volume and hypertrophy of the medullary cords, which seemed about medullary substance B-zone stimulation were characteristically for the lymph nodes, localize in the venous congestion area. The sharp increase of the marginal sinus volume during the long experimental time and paracortical T-zone hyperplasia were characteristically for the lymph nodes, which clean the venous congestion area.     

SERCA pump isoform expression in endothelium of veins and arteries: Every endothelium is not the same

Endothelium from rat aorta expresses sarco/endoplasmic reticulum Ca₂₊(SERCA) pump gene SERCA3 where as the smooth muscle expresses SERCA2. This has led to the postulate that vascular endothelium expresses SERCA3. To test this postulate, we examined the SERCA2 and SERCA3 mRNA expression in endothelium and smooth muscle dissected from coronary artery, coronary vein, aorta and vena cava of pig. Smooth muscle from all arteries and veins expressed only the SERCA2 mRNA. Endothelium from coronary artery, coronary vein and aorta expressed both SERCA2 and SERCA3 mRNA but the endothelium from vena cava did not express SERCA3 mRNA although it expressed SERCA2. These observations support the postulate that vascular endothelium expresses SERCA3 but the affirmation is equivocal because vena cava endothelium does not express SERCA3. (Mol Cell Biochem 000: 000-000, 1999)     

Small bowel transplantation in mice

Since 1990, the development of tacrolimus-based immunosuppression and improved surgical techniques, the increased array of potent immunosuppressive medications, infection prophylaxis, and suitable patient selection helped improve actuarial graft and patient survival rates for all types of intestine transplantation. Patients with irreversible intestinal failure and complications of parenteral nutrition should now be routinely considered for small intestine transplantation. However, Survival rates for small intestinal transplantation have been slow to improve compares increasingly favorably with renal, liver, heart and lung. The small bowel transplantation is still unsatisfactory compared with other organs. Further progress may depend on better understanding of immunology and physiology of the graft and can be greatly facilitated by animal models. A wider use of mouse small bowel transplantation model is needed in the study of immunology and physiology of the transplantation gut as well as efficient methods in diagnosing early rejection. However, this model is limited to use because the techniques involved is an extremely technically challenging. We have developed a modified technique. When making anastomosis of portal vein and inferior vena cava, two stay sutures are made at the proximal apex and distal apex of the recipient s inferior vena cava with the donor s portal vein. The left wall of the inferior vena cava and donor s portal vein is closed with continuing sutures in the inside of the inferior vena cava after, after one knot with the proximal apex stay suture the right wall of the inferior vena cava and the donor s portal vein are closed with continuing sutures outside the inferior vena cave with 10-0 sutures. This method is easier to perform because anastomosis is made just on the one side of the inferior vena cava and 10-0 sutures is the right size to avoid bleeding and thrombosis. In this article, we provide details of the technique to supplement the video.