Successful recovery with venovenous ECMO for ARDS after LVAD HeartMate 3 implantation: A case report.

Acute respiratory distress syndrome (ARDS) following left ventricular assist device (LVAD) implantation is a rare complication. Venovenous (VV) extracorporeal membrane oxygenation (ECMO) is used as a treatment for severe ARDS and pneumonia. We report the successful use of VV ECMO for ARDS Klebsiella pneumonia following urgent LVAD HeartMate 3 implantation.

Human embryonic stem cells as models for trophoblast differentiation.

Trophectoderm is specified from pluripotent blastomeres at some time prior to blastocyst formation. Proliferating cytotrophoblast derived from trophectoderm is the forerunner of the entire trophoblast component of the mature human placenta, including extravillous cytotrophoblast and syncytiotrophoblast. Recently human embryonic stem cells (hESC) have been employed to study these events in an in vitro situation. Here we review some of the work in this emerging area of trophoblast biology. We concentrate primarily on a model in which colonies of hESC are exposed to BMP4 in stem cell growth medium lacking FGF2. Under both low (4%) and high (20%) O(2) conditions, differentiation proceeds unidirectionally towards trophoblast from the outside of the colonies inwards, with the progression fastest under high O(2). Immunohistochemical observations performed on whole colonies combined with microarray analysis of mRNA can be employed to track developmental transitions as they occur over time and in two-dimensional space as the cells respond to BMP4.

Isolation and identification of human lung tumor-associated antigens.

Three human lung tumor-associated antigens (TAA's) have been identified in soluble and membrane-solubilized extracts of human squamous cell lung carcinoma with the use of antisera raised in rabbits. The antigens were identified and partially characterized by means of an agarose adsorption technique. These antigens, termed lung TAA's 1,2, and 3, are all soluble in 50% ammonium sulfate, are antigenically distinct, and do not cross-react with carcinoembryonic antigen or alpha-fetoprotein. Lung TAA's 1 and 2 are oncofetal antigens demonstrable in soluble extracts from 24-week-old but not from 26-week-old fetal lungs. Rabbit antibodies to these lung TAA's were not adsorbed by types A, B, and O human red blood cells, serum proteins as well as soluble or insoluble lung preparations. Of several commercial antisera to human proteins, none cross-reacted with lung TTA 1, but anti-human liver ferritin cross-reacted with lung TAA 2, and anti-human lactoferrin cross-reacted with lung TAA 3. Lung TAA 1 was partially adsorbed and cross-reacted with certain normal serum or plasma preparations used and appears to be a normal serum protein in Cohn Fraction IV-4. Lung TAA 2 and 3 appear only in lung tumor-soluble extracts, whereas the lung TAA 1 was demonstrable in soluble extracts of breast, colon, cervical and head and neck carcinoma. All may be tumor markers of value in immunodiagnosis.

Prostaglandin F2alpha stimulates the Raf/MEK1/mitogen-activated protein kinase signaling cascade in bovine luteal cells.

Upon binding to its G protein-coupled transmembrane receptors, the actions of PGF2alpha on the corpus luteum are initiated by the phospholipase C/diacylglycerol-inositol 1,4,5-trisphosphate (InsP3)/Ca2+-protein kinase C (PKC) pathway. However, little is known about the downstream intracellular signaling events that can lead to transcriptional activation in response to PGF2alpha. The present study was conducted to examine the involvement of the mitogen-activated protein kinase (MAPK) signaling cascade in the corpus luteum. Three isoforms of the Raf family of oncoprotein kinases (A-Raf, B-Raf, and Raf-1 or c-Raf) were detected in bovine luteal cells. Raf-1 and B-Raf, but not A-Raf, were activated by PGF2alpha (1 microM) and the pharmacological PKC activator phorbol myristate acetate (PMA, 20 nM). Kinetic analysis revealed that PGF2alpha rapidly and transiently activated Raf-1. In vitro protein kinase assays demonstrated that activation of Raf-1 and B-Raf resulted in the phosphorylation and activation of MAPK kinase (MEK1), which subsequently phosphorylated p42mapk. As determined by hyperphosphorylation, tyrosine phosphorylation, and enzymatic activity, p42mapk and p44mapk were rapidly and transiently activated by both PGF2alpha (1 microM) and PMA (20 nM). Additionally, both PGF2alpha (1 microM) and PMA (20 nM) stimulated phosphorylation of Raf-1, MEK1, and p42mapk in 32P-labeled cells. Our data demonstrate that PGF2alpha activates the Raf/MEK1/p42/44mapk signaling cascade in bovine luteal cells and that the actions of PGF2alpha are mimicked by the PKC activator PMA. Activation of the Raf/MEK1/MAPK signaling cascade by PGF2alpha in luteal cells provides a mechanism to transduce signals initiated by PGF2alpha receptors on the cell surface into the nucleus. Activation of the Raf/MEK1/MAPK signaling cascade may be associated with transcriptional activation of luteal genes possessing activator protein-1-binding sites.

Terminal stages of complement hemolysis: technical comment.

In studying terminal lytic events of sensitized erythrocytes which have reacted with all 9 components of complement, we agree in general with the conclusions of Boyle and Borsos [1] that the cellular intermediate passes through the stages E*bound, E*inserted, and E*doomed. However, we differ with these workers on the influence of 3 variables on the terminal reactions. These variables are: time of hemolysis; temperature of E* preparation; and the use of EDTA to manipulate E*.

The effect of cholecystokinin-receptor antagonists on cholecystokinin-stimulated bile flow in dogs.

Cholecystokinin is a choleretic in dogs. Some of the effects of cholecystokinin in stimulating bile flow in dogs are produced by cholecystokinin stimulating the release of other choleretic hormones such as insulin and glucagon. The purpose of this study was to determine the effects of cholecystokinin receptor antagonists on canine hepatic bile flow and insulin and glucagon release from the pancreas. Cholecystokinin octapeptide (CCK-8) and intraduodenal fat were administered to dogs that had undergone cholecystectomy with chronic biliary fistulas with and without the administration of cholecystokinin receptor antagonists. Bile secretion and systemic venous insulin, glucagon, and cholecystokinin levels were measured. The cholecystokinin receptor antagonists benzotript and CR 1409 had no effect on bile flow or hormone levels when administered without cholecystokinin, whereas proglumide produced a large increase in bile flow without altering hormone levels. The response produced by proglumide may be the result of an osmotic effect produced by the substance being secreted in bile and its stimulating bile salt secretion in bile. CCK-8 and intraduodenal fat increased bile flow, bile chloride secretion, and cholecystokinin, insulin, and glucagon concentrations in venous blood. The cholecystokinin receptor antagonists benzotript and CR 1409 significantly decreased the bile flow and insulin and glucagon changes produced by exogenous CCK-8. The effect of intraduodenal fat on bile flow was not inhibited by the cholecystokinin receptor antagonists, whereas the increased insulin and glucagon levels were decreased significantly. Intraduodenal fat may release other choleretic hormones not affected by cholecystokinin receptor antagonists. The choleresis produced by exogenous CCK-8 is inhibited by cholecystokinin receptor antagonists, perhaps by inhibiting the release of the choleretic hormones insulin and glucagon.

Complement activation during prolonged extracorporeal membrane oxygenation.

Short-term cardiopulmonary bypass activates the complement system, possibly resulting in pulmonary dysfunction from granulocyte aggregation and pulmonary endothelial damage. These effects may be inhibited by steroids. Prolonged extracorporeal membrane oxygenation (ECMO) is used for newborn respiratory failure, but the effects of ECMO on complement activation are unknown. Twenty-one newborn infants with respiratory failure treated with ECMO were randomly assigned to group I (control, no steroids) or group II (30 mg/kg intravenous methylprednisolone before ECMO). Depletion assays of C3 and C5 were performed in each group at intervals before and during ECMO (declining values indicate complement activation). The groups were compared for complement levels, survival, time on ECMO and on the ventilator, and total hospitalization time. Steroids significantly shortened the time on ECMO and time on the ventilator after ECMO but did not affect survival or total hospitalization time. Steroids also enhanced activation of C3 and C5. Complement activation occurs during ECMO. Steroid administration paradoxically causes earlier complement activation but shortens ECMO and ventilator times. Complement activation during ECMO is of questionable significance. The benefits of steroids during ECMO may be mediated through other mechanisms.

Evaluation of prostacyclin production by human gallbladder.

The prostanoids have been demonstrated to be involved in gallbladder physiology and disease. In previous reports, prostaglandin E (PGE) compounds were found to be increased in inflamed human gallbladders. Prostaglandin synthetase inhibition decreased PGE formation by human gallbladders; however, the relief of symptoms of cholecystitis did not correlate well with the decrease in PGE formation. This suggested that other prostanoids may be involved in cholecystitis. The purpose of this study was to evaluate the production of the proinflammatory arachidonic acid metabolite prostacyclin by gallbladders from patients with calculous cholecystitis. The formation of PGE and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha), the stable metabolite of prostacyclin, in normal human gallbladder mucosal cells and muscle tissue was compared with that produced by diseased mucosal cells and muscle tissue. Normal human gallbladders produced small amounts of 6-keto-PGF1 alpha, and no differences in formation rates were evident when muscle tissue was compared with mucosal cells. Diseased gallbladders produced significantly greater amounts of 6-keto-PGF1 alpha than did normal gallbladders, and diseased gallbladder muscle produced approximately four times greater amounts of 6-keto-PGF1 alpha than did diseased gallbladder mucosa. Prostacyclin formation is increased in diseased human gallbladders and may be an important mediator of the inflammatory changes of cholecystitis.

Neonatal diaphragmatic hernia. An improving outlook with extracorporeal membrane oxygenation.

In a 15-year period, 89 newborns were treated for congenital diaphragmatic hernia. The patients were divided into three groups, depending on postoperative therapeutic support available: group 1, ventilator therapy only; group 2, ventilator therapy plus pulmonary vasodilators (tolazoline hydrochloride); and group 3, ventilators, tolazoline, and/or extracorporeal membrane oxygenation (ECMO). The three groups were identical for presenting symptoms, signs, and preoperative blood gas determinations. The survival for each group was as follows: group 1, 17 (40%) of 42; group 2, 14 (45%) of 31; and group 3, 12 (75%) of 16. Complications requiring further operations were identical. All survivors in groups 1 and 2 are normal developmentally, while one of five group 3 ECMO survivors has developmental delay and another has long-term ventilator dependence. These data suggest that ECMO, an invasive technique for newborn respiratory failure, improves survival in congenital diaphragmatic hernia.

Degenerative neuropathy in insulin-treated diabetic rats.

Peripheral neuropathic alterations associated with diabetes and its treatment with insulin were studied in alloxan-induced diabetic rats. Treatment regimens included daily injections of Protamine Zinc Insulin (PZ), daily injections of Ultralente Insulin and subcutaneously implanted osmotic minipump delivered insulin. Non-diabetic and untreated diabetic groups served as controls. Two separate but similar studies were run, one lasting 4 weeks and the other 8 weeks. Conduction velocities performed on both sensory and motor nerves revealed no statistically significant differences among groups. Anatomical analysis of teased fibers from tibial nerves showed a significant number of fibers with ovoids, consistent with Wallerian-type axonal degeneration, only in the treated diabetic groups. Degeneration was especially severe in the PZI-treated group. Metabolic studies were performed using incorporation of radioactive isotopes ([3H]fucose, [14C]leucine) into myelin proteins of sciatic nerves. The ratio of [3H]fucose/[14C]leucine for the PZI-treated group was significantly decreased when compared to the control groups in both the 4 and 8 week study whereas the minipump-treated group showed no statistically significant difference from the control group in either study. Similar decreases in this ratio have been seen in conditions of peripheral nerve degeneration. It is concluded that daily injections of PZI insulin result in significant nerve degeneration in the alloxan diabetic rat, while continuous levels of insulin delivered by osmotic minipumps result in less degeneration.

Neuropathic changes associated with insulin treatment of diabetic rats: electron microscopic and morphometric analysis.

Tibial nerves from control, untreated alloxan diabetic, and 4-week insulin treated alloxan diabetic rats were examined with light microscopy and computerized morphometric analysis of axons. Teased fiber preparations and electron microscopy were utilized to evaluate nerve degeneration. The insulin treatment regimens included daily injections of protamine zinc insulin (PZI), daily injections of ultralente insulin, and continuously delivered insulin through osmotic minipumps. Evaluation of axon:myelin ratios, teased fiber profiles, and electron microscopic cross sections of nerves demonstrated different degrees of neuropathic changes within the treated groups. The control group and untreated diabetic group showed little or no degeneration, while all insulin-treated groups showed evidence of Wallerian degeneration. Among these insulin treated groups, the PZI-treated group showed the greatest number of degenerating profiles while the minipump group showed the least. These data suggest that insulin treatment of alloxan diabetes results in axonal degeneration which closely resembles findings in human diabetic neuropathies. The substantially diminished number of degenerating axons seen in the osmotic minipump insulin-treated rats suggests that continuous delivery of insulin may decrease the neuropathic changes seen with single injection insulin therapy. Since virtually all insulin-dependent diabetic patients receive daily administration of insulin, the possibility that peripheral neuropathies may in part result from the insulin treatment requires more extensive investigation in a variety of animal models to separate the neuropathic effects of diabetes from the neuropathic effects of insulin therapy.

Role of glucagon and insulin in canine bile flow stimulated by endogenous cholecystokinin release.

The role of endogenous cholecystokinin (CCK) in stimulating hepatic bile flow was evaluated. Attention was directed at discerning the relative importance of the ability of CCK to stimulate the release from the pancreas of the choleretic hormones glucagon and insulin. Utilizing dogs with chronic biliary and gastric fistulas, duodenal infusion of a lipid emulsion resulted in an increase in cholecystokinin concentration and hepatic bile flow. Endogenous CCK stimulation was associated with a significant increase in the concentrations of both glucagon and insulin. In an effort to separate the potential choleretic response of CCK from that of glucagon and insulin, subsequent experiments were performed on anesthetized dogs that had the source of glucagon and insulin eliminated by pancreatectomy and gastrectomy. The duodenum and its arterial blood supply and venous drainage were carefully preserved, and intraduodenal infusion of emulsified lipid resulted in an exaggerated increase in systemic CCK concentrations. Although CCK release occurred in the absence of the pancreatic and gastric changes in bile flow, glucagon and insulin were eliminated. The results of this study indicate that intraduodenal lipid increases hepatic bile flow by glucagon- and insulin-mediated CCK stimulation. There is no evidence to support any direct choleretic activity of CCK.

Congenital diaphragmatic hernia beyond infancy.

Congenital diaphragmatic hernia (CDH) is a common cause of severe respiratory distress in the newborn. However, the presentation of CDH in older children and adults is rare, and, therefore, little is known concerning its symptoms, operative management, and postoperative complications. Thirteen patients (age range: 2 months to 26 years; 5 males, 8 females) presented with CDH. Four patients had right-sided hernias, eight left-sided hernias, and one bilateral hernias. Symptoms included chronic respiratory tract infections in 6 patients, vomiting in 5, weight loss in 1, severe failure to thrive in 2, and severe respiratory distress in 3; one patient was asymptomatic. Physical signs included the absence of breathing sounds or bowel sounds in the chest in eight patients, hyperresonance in one, and cachexia in two. The diagnosis was confirmed in each patient by chest roentgenogram or gastrointestinal contrast radiograph. All patients underwent immediate repair. After reduction of the viscera, 12 of 13 patients underwent primary diaphragm repair, whereas one patient required a prosthetic diaphragm patch. Twelve of 13 patients (92%) survived. Postoperatively, 7 of the 12 survivors (58%) developed severe gastric atony, and four required further operative therapy. In contrast to newborns, CDH in the older child and adult is frequently seen on the right side, rarely presents with severe respiratory distress, and is occasionally asymptomatic. Postoperative gastric atony is a major cause of morbidity, making transabdominal repair with simultaneous pyloroplasty and/or feeding jejunostomy the preferred operative approach.

Exposure of the anterior spine. Technique, complications, and results in 85 patients.

The anterior approach to the spine is necessary for correction of some congenital spinal deformities and other conditions, including spinal trauma, infection, and tumor. The morbidity associated with this procedure has not been extensively reviewed in the literature. Between 1981 and 1986, 85 patients (41 male and 44 female) aged 1 to 77 years underwent anterior spinal fusion by an orthopedic or general surgery team (33 pediatric patients and 52 adult patients). Thirty-four patients had scoliosis, 8 had kyphosis, 24 had spinal trauma, 9 had tumor, and 10 had infection. Fifteen patients had restrictive lung disease diagnosed by pulmonary function testing (10 children and 5 adults). The thoracoabdominal approach was used in 50 patients, thoracotomy in 22 patients, and the lumbar approach in 10 patients. Two incisions were used in three patients. Correction was accomplished by interbody fusion in 36 patients (17 with instrumentation) and strut graft in 49 patients (6 with instrumentation). Twelve strut grafts were vascularized ribs and 37 were free ribs. Eighty-two patients survived (96 percent). Seventy-four complications occurring in 50 patients all resolved prior to discharge. These included 28 pulmonary complications, 27 urinary complications, and 5 gastrointestinal complications. Three patients required prolonged mechanical ventilation. Solid fusion was seen in 78 of 85 patients, whereas pseudoarthrosis developed in 7.

A reproducible, safe jejunostomy replacement technique by a percutaneous endoscopic method.

Patients undergoing esophagogastrectomy for cancer often benefit from postoperative nutritional support and an operative jejunostomy is frequently placed at the time of surgery. If the original tube has been removed, replacement of this jejunostomy previously required repeat laparotomy. Described here is the technique of direct percutaneous endoscopic jejunostomy placement (PEJ) used in two such patients following esophagogastrectomy. This PEJ placement technique using a #16-Fr, Pezzer-type Ponsky tube is an easy, reproducible method for the replacement of an operative jejunostomy tube. The fibrosed tract between the abdominal wall and jejunum allows the safe performance of the procedure if one endoscopically identifies the site of operative insertion.

The effects of perfluorochemicals on tumor growth and chemotherapy response.

Hypoxia, leading to cells in resting or slow replication phases may be a cause of chemotherapy and radiation therapy resistance in some tumors. Perfluorochemicals (PFC) may potentiate response to these therapies by increasing oxygen delivery to the tumor, forcing cells into more therapy-responsive replicating phases. To assess the effects of PFC on tumor growth and chemotherapy response, 91 ACI rats bearing 1 cc flank Morris hepatoma tumors were divided into groups: Group I, control; Group II, Adriamycin (ADR) 10 mg/kg intraperitoneally (IP); Group III, Cytoxan (CTX) 100 mg/kg IP; Group IV, PFC 20 mL/kg IV; Group V, ADR and PFC; Group VI, CTX and PFC. Animals were kept in 0.5 FiO2 for 24 hours after treatment, and mortality and tumor volumes determined 2 weeks later. Tumor DNA turnover was measured using opposing pathways assay of 14C-thymidine uptake and degradation. In a separate group, tumor tissue pO2 was measured polarographically with an oxygen microelectrode before and after injection of PFC (20 mL/kg). The survival was significantly reduced in group IV (4%) compared with group I, control (73%). Both ADR and CTX slowed the growth of the tumor, while PFC alone significantly accelerated tumor growth. The tumor response to ADR was potentiated by the addition of PFC. These results were confirmed by DNA synthesis evaluation. The mean pO2 level prior to injection was 6.6 +/- 1.96 mmHg compared with 18.92 +/- 1.00 mmHg after PFC injection (P less than or equal to .01).(ABSTRACT TRUNCATED AT 250 WORDS)

A clinical-pathological study of nonsurvivors of newborn ECMO.

Extracorporeal membrane oxygenation (ECMO) is an important means of supporting newborns with respiratory failure. While short- and long-term follow-up of ECMO survivors has been thoroughly addressed, there is no systematic study of nonsurvivors. Nineteen nonsurvivors of newborn ECMO with autopsy results are divided into two groups: group 1: 12 patients who had intracranial lesions as the primary cause of death (hemorrhage 8, encephalomalacia 2, infarct 2); and group 2: 7 patients with nonintracranial primary causes of death. Patients in group 1 were significantly more acidotic, hypotensive, and smaller in age and birth weight pre-ECMO. Among group 2 patients, two with diaphragmatic hernia died of primary pulmonary disease (diffuse alveolar damage, pulmonary hypoplasia and necrosis, bronchopneumonia). One of 2 patients with persistent fetal circulation (PFC) was treated with massive doses of tolazoline and suffered fatal gastrointestinal hemorrhage and ischemic necrosis of heart, spleen, testes, and adrenals. The other PFC patient had severe pulmonary interstitial fibrosis. Two patients with meconium aspiration and a patient with streptococcal sepsis had diffuse pulmonary damage and multiple organ failure (renal medullary necrosis, and infarcts of adrenal, spleen, liver). In this series, intracranial pathology was the most common cause of death in ECMO patients, related to gestational age, acidosis, hypoxia, and size, but probably unrelated to carotid ligation.

Malignancy associated with ureterosigmoidostomy: detection by mucosa ornithine decarboxylase.

Urinary diversion into the gastrointestinal tract (ureterosigmoidostomy) is associated with stepwise malignant degeneration of colonic mucosa. Early detection of such malignancy can be difficult. Ornithine decarboxylase (ODC) is an enzyme that initiates polyamine synthesis that is elevated in malignant colonic mucosa, but its level in premalignant mucosa after ureterosigmoidostomy is unknown. Ten Wistar rats underwent urinary diversion (bladder trigone to sigmoid colon), and were maintained on a regular diet with antibiotics for 6 months, then killed. All animals developed metaplastic changes histologically at the anastomosis. Mean ODC levels of colonic mucosa at the anastomosis v normal colon 8 cm proximal were 515 +/- 177 pmole v 24.5 +/- 4.4 (P less than .01). These data show that premalignant changes in colonic mucosa after ureterosigmoidostomy can be detected by elevated colonic biopsy ODC levels. Periodic sigmoidoscopy with colon mucosa biopsy for histology and ODC levels in children with ureterosigmoidostomy is recommended.

Reactivity of vitamin A derivatives and analogues with vitamin A antibodies.

Vitamin A antibodies were obtained using retinoic acid conjugated to human serum albumin as an immunogen. The following constraints governed the reactivity of vitamin A analogues with such an anti-serum. The stereochemistry of the side chain is relatively unimportant, and 9- and 13-cis retinal react almost as well as all-trans retinal. The nature of the ring is important; all of the compounds that react readily carry a beta-ionic ring; all of the compounds bearing an aromatic ring react poorly; the two compounds that display intermediate reactivity have non-aromatic 6- and 5-membered rings, respectively.

Vitamin A antibodies: application to radioimmunoassay.

A radioimmunoassay for serum vitamin A is described which can detect as little as 1 ng of retinol. The statistical characteristics of this assay are presented and its use in a nutritional experiment is discussed.