Lymphatic drainage of hypertonic solution from peritoneal cavity of anesthetized and conscious sheep

Lymphatic drainage of the peritoneal cavity may reduce ultrafiltration in continuous ambulatory peritoneal dialysis. We assessed lymphatic drainage of the peritoneal cavity in sheep under dialysis conditions by cannulation of the relevant lymphatic vessels and compared lymphatic drainage in anesthetized and conscious animals. Lymph was collected from the caudal mediastinal lymph node and the thoracic duct, both of which are involved in the lymphatic drainage of the ovine peritoneal cavity. Volumes of a hypertonic dialysis solution (50 ml/kg 4.25% Dianeal) containing 25 microCi 125I-human serum albumin were instilled into the peritoneal cavity, and lymph flows and the appearance of labeled protein in the lymphatic and vascular compartments were monitored for 6 h. Intraperitoneal pressures increased 4-5 cmH2O above resting levels after infusion of dialysate. On the basis of the appearance of tracer in the lymph, drainage of peritoneal fluid into the caudal lymphatic was calculated to be 3.09 +/- 0.69 and 14.14 +/- 2.86 ml/h in anesthetized and conscious sheep, respectively. Drainage of peritoneal fluid into the thoracic duct preparations was calculated to be 1.32 +/- 0.33 and 14.69 +/- 5.73 ml/h in anesthetized and conscious sheep, respectively. Significant radioactivity was found in the bloodstream, and at least a portion of this was likely contributed by the right lymph duct, which was not cannulated in our experiments.(ABSTRACT TRUNCATED AT 250 WORDS)     

51Cr-RBCs and 125I-albumin as markers to estimate lymph drainage of the peritoneal cavity in sheep

The purpose of this study was to compare the use of 125I-labeled human serum albumin (125I-HSA) and autologous 51Cr-labeled red blood cells (51Cr-RBCs) as lymph flow markers to estimate lymph drainage of the peritoneal cavity in conscious sheep. In one group, we assessed lymph drainage from the appearance of intraperitoneally administered tracer in the bloodstream. To determine distribution of drainage into discrete lymph compartments, in a second group of studies, lymph was collected from the caudal mediastinal lymph node and the thoracic duct, both of which are involved in lymphatic drainage of the ovine peritoneal cavity. Ringer lactate solution (50 ml/kg) containing 8-10 microCi each of 125I-HSA and 51Cr-RBCs was infused into the peritoneal cavity. Lymph drainage was calculated by dividing the change in mass of tracer in the blood or lymph compartments by the average intraperitoneal tracer concentration. In noncannulated animals, lymph drainage averaged over 6 h was higher with 125I-HSA as tracer (1.35 +/- 0.12 vs. 0.62 +/- 0.19 ml.h-1.kg-1 with 51Cr-RBCs). A similar pattern was noted in terms of drainage into the caudal lymphatic (0.89 +/- 0.23 and 0.52 +/- 0.19 ml.h-1.kg-1 with 125I-HSA and 51Cr-RBCs, respectively) and thoracic duct (0.16 +/- 0.06 and 0.05 +/- 0.02 ml.h-1.kg-1 with 125I-HSA and 51Cr-RBCs, respectively). Analysis of 125I-HSA and 51Cr-RBC concentrations in lymph and intraperitoneal fluid suggested sieving of RBCs at the diaphragmatic stomata or lymph nodes. Using 125I-HSA as tracer and combining data from noncannulated and cannulated sheep, we estimated peritoneal lymph drainage to be 1.35 ml.h-1.kg-1, with 66% of this flow drained by the caudal vessel, 22% by the parasternal pathway (right lymph duct), and 12% by the thoracic duct.     

Pathogenesis of malignant ascites formation: initiating events that lead to fluid accumulation

Initiating events leading to the accumulation of malignant ascites in the peritoneal cavity were investigated in two syngeneic transplantable murine ascites-producing tumors, MOT mouse ovarian tumor and the TA3/St mammary carcinoma. The transport of two tracers, 125I-labeled human serum albumin (125I-HSA) and 51Cr-labeled red blood cells (51Cr-RBC), into and out of the peritoneal cavity was studied at early times after i.p. tumor cell injection, prior to abundant fluid accumulation, and at intervals of 5 to 360 min after i.v. or i.p. tracer injection. Tracer influx and efflux rates were estimated from the mass of tracer passing into or out of the peritoneal cavity following a bolus injection of tracer into either the blood or the peritoneal cavity. Efflux of 125I-HSA from the peritoneal cavity was markedly reduced (3- to 5-fold) within 1 day of i.p. injection of either type of tumor cell. Significantly reduced efflux preceded any increase in tumor cell number and by itself did not induce peritoneal fluid accumulation. 125I-HSA tracer influx from plasma to peritoneal fluid did not increase detectably until 5 to 7 days after tumor cell injection, when the tumor cell number had increased by 10- to 100-fold. Only at relatively late stages of ascites tumor growth, when the flow rate into the peritoneal cavity had increased relative to the flow rate out of the peritoneum, was there net peritoneal fluid accumulation. Thus, increased influx, in addition to impaired efflux, were required for malignant ascites accumulation. Following i.p. injection, the efflux rates of 125I-HSA always exceeded those of 51Cr-RBC, even in ascites tumor-bearing animals. Furthermore, 125I-HSA tracer disappeared from the peritoneal cavity more rapidly than it appeared in the plasma, suggesting that 125I-HSA moves more rapidly through the channels by which 51Cr-RBC egress from the peritoneum (primarily diaphragmatic lymphatics) and/or has access to additional pathways not open to 51Cr-RBC. Finally, flow rates into and out of the blood and peritoneum were used to obtain kinetic parameters that characterized tracer transport: k1, the rate constant for tracer transport from the blood to the peritoneum; k2, the rate constant for tracer transport from the peritoneal cavity to the blood; and k6, the rate constant for tracer transport from the peritoneal cavity to surrounding interstitial tissue.(ABSTRACT TRUNCATED AT 400 WORDS)     

Vasopressin modulation of peritoneal, lymphatic, and plasma drug exposure following intraperitoneal administration

i.p. administration of cytotoxic drugs for the treatment of regionally confined cancers results in a greater total drug exposure [area under the concentration x time curve (AUC)] for the peritoneal fluid and regional lymphatics than for plasma. We sought to augment the relative advantage of i.p. administration further through modulation of peritoneal clearance by reduction in splanchnic blood flow. Pigs were treated with 5-fluorouracil, etoposide (VP-16), and carboplatin (CBDCA) alone by the i.p. route or with the same drugs in combination with i.v. lypressin, a synthetic vasopressin analogue, which reduces splanchnic blood flow. Drug concentrations in peritoneal fluid, plasma, and thoracic duct lymph were monitored over the ensuing 6 h. The pharmacokinetics of 5-fluorouracil were not altered by vasopressin; however, vasopressin increased the peritoneal fluid:plasma AUC ratio for CBDCA from 30.6 +/- 5.6 to 70. 6 +/- 7.4 (P < 0.01) and increased the lymph:plasma AUC ratio from 1.1 +/- 0.4 to 2.6 +/- 0.22 (P < 0.05). In the case of VP-16, vasopressin increased the peritoneal fluid:plasma AUC ratio from 129 +/- 35 to 350 +/- 76 (P < 0.05) and the lymph:plasma AUC ratio from 2.1 +/- 0.6 to 10.6 +/- 3.5 (P < 0.05). Concurrent i.v. administration of vasopressin can increase the pharmacokinetic advantage of the i.p. route of administration of CBDCA and VP-16 markedly in the pig model. These data suggest that the strategy of concurrent i.p. administration of CBDCA or VP-16 plus an agent that reduces splanchnic blood flow may increase the dose intensity in the abdominal cavity and intraabdominal lymphatic tissue substantially without increasing systemic toxicity.     

Developmental transitions in the myosin heavy chain phenotype of human respiratory muscle

The renal lymphatic system plays an important role in removing excess fluid from the kidneys. Unfortunately, the factors influencing lymphatic flow are difficult to measure. We used a simple model to represent renal lymphatics as a single pressure source (PL) pushing lymph through a single resistance (RL). In anesthetized dogs, we cannulated renal lymphatics and measured lymph flow rate (QL) as we varied pressure (PO) at the outflow end of the lymphatics. There was no significant change in QL as we increased PO from -5 to 0 cm H2O. In other words, there was a plateau in the QL vs. PO relationship. At higher PO's, QL decreased linearly with increases in PO. From this linear relationship, we calculated RL as -delta PO/ delta QL and we took PL as the PO at which QL = 0 microliter/min. At baseline, RL = 0.34 +/- 0.14 (SD) cm H2O.min/microliter and PL = 8.2 +/- 4.4 cm H2O. When we increased renal venous pressure (PV) from baseline (3.5 +/- 3.0 cm H2O), the plateau in the QL vs. PO relationship extended to higher PO's, RL decreased, and PL increased. Renal interstitial fluid volume and interstitial pressure increased following elevation of PV. The extension of the QL vs. PO plateau with increasing PV suggests that renal interstitial pressure may partially collapse intrarenal collecting lymphatics which may compromise lymph flow.     

A quantitative measurement of peritoneal drainage in malignant ascites

With a two-compartment model, a method is described for quantitative determination of peritoneal drainage rates in malignant ascites. Data on twenty-four patients are presented and comparison is made with the qualitative assessment of the integrity of diaphragmatic and mediastinal lymphatics on the basis of lymphoscintigrams. It is concluded that flow rates less than 50 ml/hour are usually associated with abnormalities of the diaphragmatic and mediastinal lymphatics, indicating that tumor permeation of these structures is a significant contributing factor to persistent, intractable ascites in patients with malignant diseases.     

Experimental antitumour activity of S 16020-2 in a panel of human tumours

OBJECTIVE: To compare the effects of inhaled nitric oxide (NO) and extracorporeal membrane oxygenation (ECMO) on oxygenation, hemodynamics, and lymphatic drainage in an oleic acid lung injury model in sheep. DESIGN: Prospective, randomized study. SETTING: Animal research laboratory. ANIMALS: Thirty female sheep, weighing 35 to 40 kg. INTERVENTIONS: Acute lung injury was induced by central venous injection of oleic acid (0.5 mL/kg body weight). A chronic lymph fistula had been prepared through a right thoracotomy 3 days before the experiment. Animals were assigned randomly to the NO group (n = 14) or the ECMO group (n = 16). When a lung injury score of > 2.5 was achieved, the animals were given NO in dosage increments of 2, 5, 10, 20, and 40 parts per million (ppm), or placed on ECMO with an FIO2 of 0.21 (ECMO-21) and then 1.0 (ECMO-100) at the oxygenator. Mechanical ventilator parameters were kept constant to isolate the effects of NO and ECMO on systemic and pulmonary hemodynamics, cardiac output, oxygenation parameters, lymph/plasma protein ratio, and lymph flow. Measurements and calculations were performed after 1 hr at each individual step of NO concentration or FIO2. MEASUREMENTS AND MAIN RESULTS: In the ECMO group, PVRI and MPAP did not change and were significantly different from the NO group. In the NO group, there was a dose-dependent decrease in venous admixture, maximal at 10 ppm NO and decreasing from 40 +/- 6% to 23 +/- 10% (p < .05). This decrease was significantly different from the ECMO group, where there was no change. There was a significant increase in PaO2/FIO2 in the NO group, maximal at 10 ppm NO (84 +/- 11 to 210 +/- 90, p < .05), but a greater increase in PaO2/FIO2 on ECMO-21 (81 +/- 14 to 265 +/- 63) and a further increase on ECMO-100 (398 +/- 100) (p < .05). The lymph/plasma protein ratio remained unchanged in both groups after induction of lung injury by oleic acid. However, lymph flow decreased by 11 +/- 6% in the NO group, whereas it increased by 14 +/- 17% in the ECMO group (p < .05). CONCLUSIONS: In an oleic acid-induced sheep model of acute lung injury, there were significant differences between the effects of NO and ECMO on acute pulmonary hypertension, hypoxemia, hypercarbia, and lymph flow. NO significantly decreases pulmonary hypertension, whereas pulmonary hemodynamics were not substantially affected by ECMO. Both interventions reversed hypoxemia, but ECMO did so to a greater degree, and only ECMO improved hypercarbia. Only NO decreased lymph flow, possibly as an effect of decreased microvascular filtration pressure. This study did not attempt to evaluate the impact of these interventions on ventilatory requirements, barotrauma, or outcome. However, this model suggests that NO therapy may moderate pulmonary hypertension and improve lymph flow in acute lung injury. Clinical studies are needed to assess whether NO therapy might be beneficial in treatment of severe acute lung injury in older children and adults.     

Calcium-induced intercellular adhesion of keratinocytes does not involve accumulation of beta 1 integrins at cell-cell contacts and does not involve changes in the levels or phosphorylation of catenins

The development of the lymphatic system in the rat diaphragm was studied from embryonic day 16 to 25 weeks after birth by histochemistry for 5'-nucleotidase, scanning electron microscopy of KOH-treated or intact tissues, and transmission electron microscopy of thin sections. On embryonic day 16, distinct lymphatics were noted in the subpleural space of the diaphragm periphery. The endothelial cells at this stage contained an abundance of rough endoplasmic reticulum, a developed Golgi apparatus and mitochondria, and fewer pinocytotic vesicles than those in adults. The subpleural lymphatics subsequently increased and formed a polygonal network. They possessed many valves, and by postnatal week 6, some thick collecting lymphatics became endowed with smooth muscle cells. On embryonic day 19, some lymphatics appeared in the subperitoneal space. They extended centripetally and had many lateral projections that subsequently became elongated and connected with those from adjacent lymphatics, thus forming a lattice-like network. During the early postnatal days, the subperitoneal lymphatics projected many bulges that subsequently became elongated, and came into contact with the pores among the mesothelial cells, thus forming lymphatic stomata connecting the lymphatic lacunae to the peritoneal cavity. The lymphatic stomata increased until postnatal week 10. The results show that lymphatics appear as early as embryonic day 16 in the subpleural space of the diaphragm periphery, and develop with age by sprouting to form networks in both the subpleural and the subperitoneal spaces, and that the direct connection of the lymphatic lacunae to the peritoneal cavity is formed after birth.     

Inhibition of coagulation by a phosphorothioate oligonucleotide

Pathways of peritoneal fluids to the pleural cavity in the rat were investigated by light microscopy and transmission electron microscopy (TEM). Intraperitoneally injected India ink was demonstrated to enter the subperitoneal lymphatics through lymphatic stomata, and to drain through the subpleural collecting lymphatics, into the parasternal, paravertebral and mediastinal lymphatic trunks as well as the thoracic duct. Five to 10 min after the intraperitoneal injection of India ink, the parasternal lymphatic trunk was ligated at the third intercostal space. Thirty minutes, 1 h, or 2 h after the ligation of either the right or the left trunk, India ink was macroscopically recognized only around the ligated trunk. When the right and left trunks were simultaneously ligated, India ink leaked around both trunks. Five hours after the ligation of both trunks, a massive amount of ink was located in the interstitium of the anterior thoracic wall. TEM revealed carbon particles passing through gaps of the lymphatic endothelial cells into the interstitial space, and partly reaching the mesothelial surface lining the anterior thoracic wall. Results show that obstruction or narrowing of the lymphatic trunks draining the diaphragmatic lymph causes a hydrothorax, indicating that this is at least one mechanism causing this during continuous ambulatory peritoneal dialysis and diseases with ascites.     

A case of Buerger''s disease solitary involved in the left subclavian and axillary artery

The pharmacokinetics of ceftazidime have been investigated in eight patients with chronic renal failure undergoing continuous ambulatory peritoneal dialysis. Each subject was given ceftazidime 1 g intravenously and 1 g intraperitoneally at an interval of 1 week. Ceftazidime was assayed by high-pressure liquid chromatography. After intravenous administration, the pharmacokinetic parameters of ceftazidime were: elimination plasma half-life (t1/2 beta) = 24.6 +/- 4.6 hours; apparent volume of distribution (V(area)): 0.37 +/- 0.09 1/kg, total plasma clearance (CL): 11.9 +/- 3.3 mL/minute, peritoneal clearance (CLp): 1.7 +/- 0.3 mL/minute. Over 72 hours, only 15.6 +/- 4.7% of the dose was eliminated by the peritoneal route. After intraperitoneal administration, ceftazidime appeared in the plasma rapidly, and the peak plasma concentration of 24.5 +/- 5.2 mg/L was achieved at the fourth hour; the elimination half-life (t1/2ke) was 20.8 +/- 1.7 hours. The absorption of ceftazidime from the peritoneal space was 74.1 +/- 7.4%. These data suggest that ceftazidime has bidirectional exchange characteristics through the peritoneal membrane. A single 1-g intraperitoneal dose led to serum and dialysate concentrations of ceftazidime above the minimum concentrations for susceptible pathogen germs for 24 hours.     

Renal lymph protein in the rat

Renal lymph and systemic (posterior) lymph were studied in hydropenic rats. As a consequence of the anatomical arrangement of collecting lymphatics near the kidney, mixed renal and systemic lymph tributaries are situated in such a way that sampling pure renal lymph is difficult. Pure renal lymph contains 1.0 +/- 0.1 g/100 ml total protein with an albumin-to-globulin (A/G) ratio of 2.1 +/- 0.1. Mixed renal and extrarenal lymphatic tributaries contain 3.3 +/- 0.2 g/100 ml total protein with an A/G ratio of 1.8 +/- 0.2. Corresponding values in the plasma are 4.9 +/- 0.2 and 1.2 +/- 0.1 g/100 ml, respectively. Previous studies in which the concentration of renal lymph protein was determined as 30-50% of that in plasma were probably in error due to contamination of renal samples by posterior lymph ducts. The amount of systemic and renal lymph mixing is highly variable from one animal to another. Our renal lymph samples in carefully controlled and prepared Munich-Wistar rats contained a total protein uniformly 20% of that in plasma.     

Hepato-splanchnic blood flow and oxygen extraction capabilities during experimental tamponade: effects of endotoxin

We studied the hepato-splanchnic vascular response and changes in O2 extraction capabilities to a reduction in blood flow following endotoxemia. Fourteen anesthetized and mechanically ventilated dogs were divided into two groups of seven each. Group 1 received 2 mg/kg of E. coli endotoxin, and group 2 served as a control. After initial fluid resuscitation following endotoxic shock, regional blood flow estimated by an ultrasonic technique increased similarly in the hepatic artery, portal vein, and mesenteric artery, but microvascular blood flow estimated by a laser Doppler technique was lower in the liver than in the intestinal mucosa. When blood flow was reduced by cardiac tamponade, endotoxin-treated animals had greater whole body and regional critical O2 delivery (DO2crit) and lower whole body, liver, and intestinal critical O2 extraction ratios (O2ERcrit). DO2crit was higher in the liver than in intestine but O2ERcrit was similar in the two organs. Whole body DO2crit at the onset of organ O2 supply dependency was similar under control (9.4 +/- 1.9 mL/kg. min for whole body, 10.3 +/- 4.7 mL/kg. min for liver, and 10.0 +/- 2.6 mL/kg. min for intestine) and endotoxic conditions (13.6 +/- 3.2 mL/kg. min for whole body, 15.6 +/- 2.7 mL/kg. min for liver, and 15.4 +/- 8.7 mL/kg. min for intestine). We conclude that fluid-resuscitated endotoxic shock in dogs is characterized by blood flow redistribution within the liver and intestine. Microvascular depression may be more severe in the liver than in the intestinal mucosa, although the whole body, the liver, and the intestine became O2 supply-dependent simultaneously.     

Appearance of airway absorption and exudation tracers in guinea pig tracheobronchial lymph nodes

This study examines the fate of extravasated plasma in inflammatory stimulus-challenged large tracheobronchial airways of ketamine-xylazine-anesthetized guinea pigs. Entry of plasma tracers into the airway lumen was determined by a validated noninjurious airway lavage technique. Removal by airway lymphatics was assessed by tracheobronchial lymph node levels of plasma tracers. Mucosal challenges with histamine (5 nmol), bradykinin (5 nmol), capsaicin (0.4 nmol), or allergen (ovalbumin, 3 pmol) increased the appearance of a plasma tracer (131I-labeled albumin previously injected intravenously) in the airway lumen within 10 min (10-20 times control; P < 0.001), whereas the contractile agent carbachol (8 nmol) was without exudative effect. The mediators were without effect, and capsaicin and allergen only slightly increased the lymph node level of plasma exudation tracer (1.5 times control; P < 0.05). Hence, removal via the lymphatic route of plasma macromolecules may be negligible in the acute and postacute phases of an airway exudation response. Experiments were also carried out with luminally applied macromolecular tracers. These were absorbed from the mucosal surface into the circulation, but a small portion was also transported to the lymph nodes, demonstrating the interconnections between the mucosa and the sampled nodes. Only capsaicin produced an increased node level of absorption tracer. Immunohistochemistry showed that the tracheobronchial tissue and lymph nodes are endowed with nerve fibers containing substance P, the release of which may have mediated lymph transport, vascular, and exudative effects of capsaicin in the present studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

The evaluation of 15q proximal duplications by FISH

BACKGROUND: Preoperative cutaneous lymphoscintigraphy (LS) to identify sentinel (first-tier) lymph nodes was performed in 250 consecutive melanoma patients before wide local excision only or wide local excision with sentinel node biopsy. METHODS: The location of the sentinel nodes was marked on the overlying skin in all patients. Whether or not tracer was present in second-tier lymph nodes on the delayed scans was recorded for each patient and related to the lesion site at which the tracer had initially been injected. For 100 consecutive patients the rate of tracer movement through the lymphatic channels was compared to the incidence of second-tier drainage. RESULTS: Second-tier nodes were visualized in all patients with melanomas on the leg and thigh, and in almost all patients with melanomas on the forearm and hand, but were seen less often in patients with more centrally located melanomas. There was a significant correlation between the rate of lymph flow and the incidence of demonstrable second-tier drainage. CONCLUSION: The results suggest that the physiology of the lymphatic system varies depending on the origin of the lymphatic vessel. These findings have important implications for application of the sentinel node biopsy technique in individual patients.     

Resuscitation from hemorrhagic shock with diaspirin cross-linked hemoglobin, blood, or hetastarch

BACKGROUND: An oxygen-transporting hemoglobin solution should be more effective than a nonhemoglobin solution for resuscitation from hemorrhagic shock. A way to evaluate this effectiveness is to determine whether a hemoglobin solution can reverse the base deficit accumulated during hemorrhage at a faster rate than a nonhemoglobin solution. Using this criterion, we compared the resuscitative powers of autologous blood, hetastarch (Het), and diaspirin cross-linked hemoglobin (DCLHb). METHODS: Fifteen sedated, spontaneously breathing sheep (37.5 +/- 10.2 kg) were bled until base deficits fell to -5 to -10 mEq/L, and plasma lactate concentrations rose to 6 to 9 mg/L. The animals were resuscitated with autologous blood (n = 5), Het (n = 5), or DCLHb (n = 5) (3.5-4.0 mL/kg every 15 minutes) until base deficits returned to prehemorrhage baseline. RESULTS: Exsanguination to target base deficits required removal of an average of 41.4 +/- 5.5 mL blood/kg (estimated total blood volume, 80 mL/kg). Resuscitation required 18 +/- 3, 38 +/- 2 (different from blood), and 35 +/- 1 (different from blood) mL/kg of autologous blood, Het and DCLHb, respectively, over periods of 78 +/- 8, 163 +/- 10 (different from blood), and 129 +/- 9 minutes (different from blood and different from Het (p < or = 0.05)). Based on regression analysis, autologous blood, Het, and DCLHb corrected the base deficit at rates of, respectively, 0.074 (different from Het (p < or = 0.05)), 0.016, and 0.056 (different from Het (P < or = 0.05)) mEq/L/min. CONCLUSIONS: Based on the rate of base deficit correction and the volume of solution required, autologous blood was the most effective resuscitation solution. However, DCLHb was more effective than Het. DCLHb may be an attractive alternative to blood for resuscitation from hemorrhagic shock.     

Lymphoscintigraphy in chyluria, chyloperitoneum and chylothorax

Lymphoscintigraphy allows functional assessment of lymphatic transport and depiction of regional lymph nodes, is fast and nontraumatic and has no known side effects. We retrospectively analyzed lymphoscintigraphic studies to determine their efficacy in the investigation of chyluria, chyloperitoneum and chylothorax. METHODS: Twenty-one whole-body lymphoscintigrams using 99mTc-antimony sulfide colloid or dextran were acquired in 18 patients with chyluria, chyloperitoneum and/or chylothorax. The images were reviewed to assess the rate of tracer transport and number, size and distribution of lymph vessels and nodes as well as the presence of collateral, fistula or lymph reflux. RESULTS: Lymphoscintigraphy was normal (5 of 11 patients) or showed lymphatic obstruction (6 of 11 patients) in chyluria associated with filariasis. Lymphatic obstruction was demonstrated in chyloperitoneum and/or chylothorax associated with liver cirrhosis (2 patients), postoperative (1 patient) or congenital (1 patient) lymphatic dysplasia, inferior vena cava obstruction (1 patient) and nephrotic syndrome (1 patient). Enhanced lymph flow was seen in systemic lupus erythematosus (1 patient). Follow-up lymphoscintigrams showed patency of lymphovenous anastomosis (1 patient), improvement (1 patient) or no change (1 patient) in lymphatic drainage after treatment. CONCLUSION: Lymphoscintigraphy can demonstrate abnormal lymphatic drainage in chyluria, chyloperitoneum and chylothorax. It is useful for selecting patients for surgery and assessing the effect of treatment.     

Uncontrolled hemorrhage from parenchymal injury: is resuscitation helpful?

Fluid resuscitation increases blood pressure and may increase hemorrhage. We tested this hypothesis in a model of liver injury. After standardized injury, rats were randomized into four groups: no resuscitation (NR, n = 30), small volume lactated Ringer's solution (SVLR, 4 mL/kg, n = 30), large volume lactated Ringer's solution (LVLR, 24 mL/kg, n = 30), and hypertonic saline (HS, 4 mL/kg, n = 30). Terminal circulating volume was estimated using controlled hemorrhage experiments. Survival times and mortality rates were significantly lower in HS animals (10%) than in NR (50%) or SVLR (47%) animals. Blood pressure was significantly higher after HS, and this difference was sustained. Intraperitoneal blood volume was significantly higher with HS (26.0 +/- 0.7 mL/kg) and LVLR (26.9 +/- 0.6 mL/kg) compared with NR (21.5 +/- 0.7 mL/kg) and SVLR (22.5 +/- 0.7 mL/kg). Estimated terminal blood volume was significantly decreased in LVLR (29.3 +/- 0.6 mL/kg) compared with NR (33.3 +/- 0.7 mL/kg), SVLR (33.7 +/- 0.8 mL/kg), and HS (31.7 +/- 0.7 mL/kg). CONCLUSION: Vigorous resuscitation increases bleeding from solid viscus injury. Small volume HS improves blood pressure and survival compared with no resuscitation. Results of large vessel hemorrhage models may not apply to parenchymal viscus injury.     

Effects of continuous infusion of endothelin-1 in pregnant sheep

Plasma concentration of endothelin-1, a potent vasoconstrictor produced by the vascular endothelium, has been observed to be significantly increased in a number of pathophysiological states, including preeclampsia. In the present study we have evaluated the effects of elevated plasma endothelin-1 in pregnant sheep by continuous exogenous endothelin-1 administration. Nine pregnant ewes (110+/-5 days' gestation) were instrumented for measurements of maternal mean arterial pressure, renal blood flow, and uterine blood flow. After recovery, endothelin-1 was infused intravenously for 4 hours at a dose that was adjusted to raise mean arterial pressure by approximately 20 mm Hg by the end of the first hour (range 5 to 20 ng/kg per minute). Mean arterial pressure, renal blood flow, uterine blood flow, urinary protein excretion, hematocrit, and plasma endothelin-1 concentration were measured hourly, and renal and uterine vascular resistances were calculated. Endothelin-1 produced significant increases (% change from baseline at t=4 hours) in mean arterial pressure (45+/-8%), renal vascular resistance (353+/-66 %), and uterine vascular resistance (59+/-21%). Endothelin-1 also increased microvascular permeability both systemically and within the kidney, as suggested by marked increases in hematocrit (0.27+/-0.01 to 0.32+/-0.01) and urinary protein concentration (0.95+/-0.1 to 7.9+/-3.2 mg/mL per mg creatinine). There was a highly significant correlation (P<.0001) between plasma endothelin-1 and mean arterial pressure, renal vascular resistance, uterine vascular resistance, hematocrit, and urinary protein content in all sheep studied. In addition, plasma endothelin-1 corresponded well with the time course of the changes in cardiovascular parameters and urinary protein excretion observed. These results provide evidence to suggest that elevation of circulating endothelin-1 in pregnant sheep can produce cardiovascular and hemodynamic changes that in many ways resemble the human disease preeclampsia. This supports the hypothesis that endothelial cell damage and/or dysfunction that is associated with increased production of endothelin-1 could directly contribute to the progression of preeclampsia.     

Marketing mix in a radiology department: challenges for future radiologists in management

Prostaglandin (PG)I2 is the primary eicosanoid synthesized by human lymphatics and 8-epi-PGF2 alpha, an isoprostane formed during free radical catalyzed peroxidation, is the most potent stimulator of lymphatic contraction tested thus far. We now examine the respective concentrations in the lymphatic wall of both human and porcine lymphatics and lymph fluid using specific immunoassays. Although both compounds are detectable in the lymphatic wall and lymph fluid, PGI2- (via its main metabolite 6-oxo-PGF1 alpha) is greater in the lymphatic wall whereas 8-epi-PGF2 alpha dominates in lymph fluid. Because inflammation is associated with oxidative injury, which in turn stimulates release of isoprostane, eicosanoid derivatives may modulate lymphatic tone during acute tissue reaction.     

Differential regional hemodynamic effects of corticotropin in conscious sheep

The regional hemodynamic effects of 5 days of intravenous infusion of corticotropin (ACTH) (5 micrograms/kg per day) were examined in conscious sheep (n = 8). Mean arterial pressure increased from 81 +/- 2 to 93 +/- 3 mm Hg (P < .001) on day 2 of ACTH and remained at this level during the infusion. Cardiac output increased from 5.13 +/- 0.19 to 6.06 +/- 0.33 L/min (P < .01) because of an increase in stroke volume from 65 +/- 4 to 79 +/- 8 mL per beat (P < .01); heart rate remained unchanged. ACTH did not alter total peripheral conductance but had differential effects on regional conductances. Mesenteric conductance fell from 5.8 +/- 0.2 to a minimum of 4.9 +/- 0.3 (mL/min)/mm Hg (P < .05), and renal conductance increased from 3.5 +/- 0.3 to 4.6 +/- 0.3 (mL/min)/mm Hg (P < .001). There was a small increase in iliac conductance (P < .05) and no change in coronary conductance. Mesenteric and iliac conductances fell progressively over 24 to 48 hours, whereas renal conductance increased rapidly after 3 hours of ACTH, reaching a maximum after 6 hours. Renal blood flow was increased during ACTH infusion from 278 +/- 18 to 403 +/- 23 mL/min (P < .001); mesenteric blood flow was unchanged; there was a small increase in iliac blood flow (P < .01); and coronary blood flow increased (P < .05), paralleling the change in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)