Inhaled nitric oxide enhances oxygenation but not survival in infants with alveolar capillary dysplasia.

A complex vascular abnormality in the lungs, termed alveolar capillary dysplasia (ACD) and misalignment of the lung vessels, has been recently recognized in some infants with persistent pulmonary hypertension. These infants die despite maximal medical support including extracorporeal membrane oxygenation (ECMO). Inhaled nitric oxide has been reported to improve oxygenation in neonates with persistent pulmonary hypertension of the newborn, and may allow some infants to avoid the need for ECMO. We identified five infants who had received inhaled nitric oxide to treat refractory hypoxemia caused by persistent pulmonary hypertension of the newborn, and who subsequently died and had autopsy confirmation of ACD. Each infant received care at a different medical center. In each patient, inhaled NO increased the arterial partial pressure of oxygen dramatically. Despite initial clinical improvement, the response to NO was not sustained in any patient. As responsiveness was lost, each infant with ACD required inhaled NO concentrations of 80 ppm or higher to sustain oxygenation. Each infant died, four after extensive periods of ECMO support. This experience demonstrates that a short-term improvement after inhalation of nitric oxide does not lead to long-term survival in ACD. Further, in three infants the diagnosis of ACD was established by lung biopsy before death. Increasing awareness of this clinical entity may allow for the avoidance of costly, invasive procedures such as ECMO until more specific therapies become available.

A program to limit donor exposures to neonates undergoing extracorporeal membrane oxygenation.

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) has dramatically improved the survival of neonates with life-threatening respiratory and cardiac failure. However, ECMO requires numerous transfusions with significant risks. This study evaluated the effects of changing transfusion practices and blood component management on blood donor exposures in neonatal ECMO. DESIGN: A 3-year retrospective chart review of all neonatal ECMO patients from December 1989 through November 1992 was undertaken. During this 3-year period, transfusion practices and blood product preparation were altered twice to reduce blood donor exposures. The use of apheresis platelets and fresh frozen plasma (FFP), and preserving the expiration date on packed red blood cells (PRBCs) through the use of a sterile connecting device, allowed multiple transfusions from individual donor components. In addition, education of the ECMO physicians was focused on standardizing and reducing transfused volumes. Sixty-four surviving neonatal patients (91.4%) were evaluated. Five patients had excessive bleeding and were excluded from analysis. The remaining 59 patients were divided into three protocols based upon the transfusion practice at the time of their ECMO course. Protocol 1 received PRBCs less than 5 days of age, volume-reduced platelet concentrates, and standard FFP units up to 24 hours after thawing. Changes in transfusion practice for protocol 2 included extended outdate for PRBCs to 10 days, and using single donor apheresis platelet aliquots. The third protocol entailed the use single donor apheresis FFP aliquots in addition to the protocol 2 changes. RESULTS: Total PRBC transfusion volumes (721 +/- 406 ml for protocol 1, 637 +/- 172 ml for protocol 3) and associated blood donor exposures (5 +/- 2.1 for protocol 1, 3.9 +/- 0.9 for protocol 3) did not change substantially over the reviewed period. However, FFP transfusion volumes (478 +/- 170 ml for protocol 1, 274 +/- 63 ml for protocol 3), FFP-related donor exposures (4.5 +/- 1.6 for protocol 1, 1.2 +/- 0.4 for protocol 3) and platelet-related donor exposures (4.6 +/- 3.6 for protocol 1, 2.5 +/- 1.5 for protocol 3) were reduced progressively and significantly from protocol 1 to protocol 3 (P < .01, Tukey's B test adjusted for multiple comparisons). The total number of donor exposures per patient while on ECMO was decreased from 14.1 in protocol 1 to 10.0 in protocol 2 to 7.5 in protocol 3 (P < .01). CONCLUSIONS: We conclude that the changes in blood bank component selection and management as well as physician practice were effective in substantially reducing ECMO-related transfusion volumes and the resulting donor exposures.

Relationship of general advance directive instructions to specific life-sustaining treatment preferences in patients with serious illness.

OBJECTIVE: To determine whether brief general instructions in a typical proxy-instruction advance directive (California Durable Power of Attorney for Health Care [DPAHC]) provide interpretable information about patient requests to limit life-saving treatments, and to determine whether patient treatment preferences are stable over time. DESIGN: Prospective structured interviews. SETTING: University of California, San Diego Medical Center and Veterans Affairs Medical Center, La Jolla. PATIENTS: One hundred four patients (from a randomly chosen sample of 185) with a 5-year life expectancy of no better than 50% as judged by their physicians. MAIN OUTCOME MEASURES: Patients completed the California DPAHC, a proxy-instruction advance directive, at entry and at 1 year. The patients also completed a questionnaire at entry, after 6 months, and after 1 year, indicating their preferences on a five-point Likert-format comparative rating scale for cardiopulmonary resuscitation, mechanical ventilation, artificial nutrition, and hospitalization for pneumonia. RESULTS: Sixty-eight percent of the subjects executed the DPAHC. Most patients wished treatments to be limited or withheld under certain conditions of reduced quality of life. Although general instructions noted on the DPAHC and preferences regarding specific procedures were stable over the course of a year, the advance directive's general instructions were often inconsistent with, and poor predictors of, specific procedure preferences. CONCLUSIONS: The brief general instruction component of the California DPAHC is not helpful in communicating patient wishes regarding specific life-saving procedures.

Successful medical treatment of presumed Candida endocarditis in critically ill infants.

Few infants have been reported who survived fungal endocarditis; all have required both surgical and intensive antifungal therapy. We describe three infants, two weighing less than 1000 gm, who survived Candida endocarditis without surgery. Two had Candida parapsilosis, an agent not previously reported as a cause of neonatal endocarditis. All three infants were treated with amphotericin B and 5-flucytosine. Despite administration of 44, 38, and 48 mg/kg amphotericin B, respectively, no nephrotoxicity was noted; 5-flucytosine therapy was stopped in one infant because of thrombocytopenia. One infant died of an unrelated cause 6 months later; there was no evidence of Candida or endocarditis at autopsy. The other two infants are thriving 2 and 3 years after the completion of antifungal therapy; no remaining evidence of endocarditis is present on echocardiography. We conclude that antifungal therapy without surgery is an option for Candida endocarditis in critically ill infants.

Electromechanical dissociation in newborns treated with extracorporeal membrane oxygenation: an extreme form of cardiac stun syndrome.

OBJECTIVE: To recognize cardiac stun syndrome and electromechanical dissociation in patients receiving extracorporeal membrane oxygenation (ECMO), and to define patients at risk. DESIGN: Retrospective review. SETTING: Tertiary neonatal ICU. PATIENTS: Four newborn patients with cardiorespiratory failure who developed signs of cardiac stun syndrome and electromechanical dissociation early in the ECMO course. MEASUREMENTS AND MAIN RESULTS: Initially, these patients had metabolic acidosis, chest roentgenograms showing pulmonary granularity and moderate cardiomegaly, and symptoms of severe respiratory distress. Cardiac dysfunction was apparent after ECMO was begun, with poor perfusion, pale color, narrow pulse pressure, and tachycardia despite normovolemia. Within 1 to 2 hrs, electromechanical dissociation occurred manifested by the absence of pulse pressure, palpable pulse, cardiac sounds, and apical impulse while on 50% to 70% bypass. All patients survived. INTERVENTIONS: Patients received ECMO, calcium gluconate, sodium bicarbonate, and dobutamine. CONCLUSIONS: Patients with cardiac stun syndrome have symptoms similar to severe respiratory distress syndrome, and may require ECMO support. In the ECMO patient, cardiac stun syndrome and electromechanical dissociation can be confused with low circuit volume, pneumothorax, or cardiac tamponade. Early recognition of electromechanical dissociation may improve care and outcome. Cardiac stun syndrome can be treated successfully with ECMO.

Otocephaly-midline malformation association.

Otocephaly ("agnathia") is a developmental field complex with structural defects limited to the craniofacial region. Previously, two infants with otocephaly, situs inversus totalis, renal defects, and vertebral and rib abnormalities were reported by Pauli et al. [Teratology 23:85-93, 1981]. We describe a similarly affected infant male, supporting the existence of this midline malformation association. A generalized disturbance in cell migration from the primitive streak may be its pathogenesis. A search for additional patients among cases of otocephaly may establish its prevalence, patterns of associated anomalies, and cause.

Evidence for the existence of a GTP-dependent factor in hepatic cytosol that stimulates cyclic AMP binding: possible role in the modulation of cyclic AMP action.

GTP, in physiologic concentration (10(-4) mol/L), enhances cAMP binding to an Mr 57,000 binding protein (BP) in hepatic cytosol, which probably is the phosphorylated receptor subunit of protein kinase II (PK II). When we attempted to separate PK II from other hepatic cytosol proteins by DEAE-cellulose chromatography, we observed that GTP caused little stimulation of [3H]cAMP binding in an eluate fraction (110 to 170 mmol/L KCI), which was rich in PK II but did stimulate cAMP binding to the 210 to 325 mmol/L KCI fraction, which also contains PK II. This suggested that the latter fraction might contain a cofactor necessary for GTP stimulation of cAMP binding, which was lacking in the 110 to 170 mmol/L KCI fraction. Cyclic AMP BP in the 210 to 325 mmol/L fraction was removed by absorption onto cAMP agarose in the presence of 325 mmol/L KCI. When an aliquot of the BP-poor fraction, containing the putative cofactor, was added to the 110 to 170 mmol/L fraction containing PK II, the addition of 10(-4) mol/L GTP to the mixture increased [3H]cAMP binding by more than 80%. Cofactor activity could be extracted from the 210 to 325 mmol/L eluate by adsorption onto cAMP agarose in the presence of 10 mmol/L K phosphate, and eluted with 100 mmol/L KCI, suggesting that the cofactor may bind to the cAMP BP under appropriate circumstances. Addition of this eluted cofactor fraction to the 110 to 170 mmol/L fraction in the presence of 10(-4) mol/L GTP, increased the specific binding of [3H] cAMP more than twofold. Pretreatment of the cofactor fraction with trypsin eliminated this effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal refractory supraventricular tachycardia: successful treatment with amiodarone.

A 3-week-old neonate with supraventricular tachycardia unresponsive to traditional therapy was treated successfully with amiodarone. An electrophysiologic study suggested the presence of a concealed left-sided accessory atrioventricular pathway. Because of its significant side effects, amiodarone should be used only as a last resort in the treatment of neonatal supraventricular tachycardia.

Effects of fasting, feeding, and insulin on enhancing effect of GTP on cAMP binding in rat hepatic cytosol.

GTP, in physiologic concentration, enhances the binding of cAMP to a protein in the hepatic cytosol that may be the regulatory subunit of protein kinase II. Ingestion of carbohydrate suppresses hepatic gluconeogenesis and glycogenolysis, two processes that are stimulated by cAMP. In this study, we have examined the possibility that carbohydrate inhibits these processes partly by decreasing the sensitivity of the GTP-responsive cAMP-binding protein to the effect of GTP. We found that 100 muM GTP was much less effective in enhancing cAMP binding in the hepatic cytosol of rats given 15% glucose for 2 days than in the cytosol of fasted rats [21 +/- 3% (mean +/- SE) increase vs. 67 +/- 6%, P less than .01]. Corresponding results were noted in diethylaminoethyl (DEAE)-cellulose extracts of the hepatic cytosol of these rats. GTP stimulation of cAMP binding was also diminished in the hepatic cytosol of diabetic rats treated for 7 days with insulin compared with that of untreated diabetic rats (29 +/- 10 vs. 81 +/- 11% increase, P less than .01), but this could have been due to increased food intake in the treated rats. We conclude that GTP stimulation of hepatic cAMP binding is decreased in the carbohydrate-fed state and that this effect may be mediated by the increase in plasma insulin induced by carbohydrate. Our observations suggest that some of the cellular effects of cAMP may be regulated by modulation of the stimulatory effect of GTP on the GTP-responsive cAMP-binding protein.

Enhancement by GTP of cAMP binding to hepatic nuclei and cytosol.

In the present study we have demonstrated specific binding of 3H-labeled adenosine 3',5'-cyclic monophosphate (cAMP) to a nuclear extract from rat liver. GTP, GDP, and low concentrations of ATP and ADP increased nuclear binding of [3H]cAMP, and AMP inhibited [3H]cAMP binding. Photoaffinity labeling studies employing [32P]cAMP revealed four nuclear binding proteins [relative molecular weight (Mr) 36,000, 49,000, 54,000 and 57,000]. Unlabeled cAMP decreased [32P]cAMP binding to all four proteins, whereas GTP increased binding to the 57,000 protein. We also observed specific binding of [3H]cAMP in the liver cytosol, which was stimulated by GTP but not by ADP or ATP. Photoaffinity labeling studies of the cytosol in the absence of unlabeled nucleotides revealed three cAMP-binding proteins (Mr 36,000, 49,000, and 54,000). Unlabeled cAMP inhibited binding of [32P]cAMP to all three proteins, whereas in the presence of GTP there was binding of [32P]cAMP to a Mr 57,000 protein. Using DEAE-cellulose, we isolated from the nuclear extract and cytosol a cAMP-binding protein that responded to GTP with an increase in cAMP binding but was unaffected by GDP, ATP, ADP, and AMP. Guanosine imidodiphosphate did not affect cAMP binding, suggesting that the stimulatory effect of GTP may be mediated by phosphorylation. We speculate that alterations in intracellular GTP in vivo may modulate the binding of cAMP to a protein in the nucleus and cytosol.

Immunohistochemical localization of cyclic guanosine monophosphate (cGMP) on mouse fetal chromosomes.

In previous immunohistochemistry studies, cyclic guanosine monophosphate (cGMP) has been found in polytene chromosomes of D. melanogaster, cGMP has not been found in mammalian metaphase chromosomes, but this could be due to loss of cGMP during staining. Thus the effect of different fixation techniques on the immunohistochemically detectable cGMP associated with metaphase chromosomes from mouse fetal tissue was examined. In chromosomes from cells fixed in 2% formalin, or unfixed cells dropped on slides preheated to 60 degrees C, there was diffuse cGMP staining. When cells were fixed in methanol:glacial acetic acid, 3:1, no chromosomal cGMP immunofluorescence was observed, whereas chromosomes from cells fixed in methanol:glacial acetic acid, 6:1, had different patterns of cGMP immunofluorescence depending on the temperature of the slides onto which the fixed cells were dropped. On slides prechilled to 4 degrees C, cGMP immunofluorescence outlined the chromosomes; on room temperature slides, faint chromosomal cGMP staining was observed, and on slides preheated to 68 degrees C or room temperature slides blown dry with hot air, the chromosomes had more intense diffuse cGMP immunofluorescence or distinct symmetrical bands of cGMP immunofluorescence. We have demonstrated the presence of cGMP in mammalian metaphase chromosomes. The different patterns of cGMP immunofluorescence observed may reflect variable preservation of chromosomal proteins that have binding sites for cGMP.

Immunohistochemical studies of cyclic guanosine monophosphate and nuclear function.

In previous immunohistochemical studies, it has been found that all nuclei contain cyclic (c)GMP, which occurs in discrete aggregates and in the nucleolus. We have studied the nature of the cGMP aggregates in isolated mouse fetal nuclei using a specific immunofluorescent technique. These aggregates correspond to the areas of condensation of DNA, demonstrable by either Felugen's or acridine orange stain. Treatment with DNAase eliminated DNA and cGMP staining. Staining for RNA, with a human anti-RNA antibody, demonstrated RNA to be distributed diffusely throughout the nucleus and not preferentially in the areas of discrete cGMP aggregates. The diffuse stain for nuclear RNA was eliminated by pretreatment with RNAase but not DNAase, but aggregates of cGMP were not affected by pretreatment with RNAase. Sites of active RNA synthesis were determined by autoradiography using [3H]uridine, and did not correspond to the aggregates of cGMP. The relationship of cGMP to nucleolar function was examined in the endothelial cells of the isthmus and ampulla of the rat fallopian tube. Previous studies have shown that in proestrous, a period of increased RNA synthesis, nucleoli detectable by staining for RNA appear in the endothelial cells lining the fallopian tube. After immunofluorescent staining, we found prominent accumulation of cGMP in the nucleoli. During other phases of the cycle, there is an absence of nucleoli detectable by staining for RNA, and an absence of nucleolar cGMP. After we treated hypophysectomized or oophorectomized rats with estrogen, which is known to increase nucleolar RMA synthesis in the fallopian tube and endometrium, nucleoli in the endothelial cells of the rat fallopian tube and uterus stained strongly for cGMP. In conclusion, our studies suggest that the discrete aggregates of nuclear cGMP are associated with a fraction of DNA uninvolved in RNA synthesis. In contrast, cGMP appears in the nucleolus during a period of increased RNA synthesis, suggesting a role for cGMP in regulating nucleolar synthesis and processing of RNA.

Effects of indomethacin on intrarenal blood flow and medullary osmolality in dogs.

The effects of indomethacin on renal blood flow (RBF) and its distribution were measured during control, during hemorrhage to 70 mm Hg and during refractory shock. Outer and inner cortical blood flow and outer medullary blood flow were measured with a freeze-dissection 133Xe disappearance technique. Control dogs treated with indomethacin exhibited a loss of blood flow to the outer medulla as well as decreases in both cortical blood flows. Hemorrhage caused the expected redistribution of RBF, the greatest part going to the inner cortex and outer medulla. Hemorrhaged dogs pretreated with indomethacin exhibited no difference from hemorrhage alone in freeze-dissection measured cortical flows, but again had marked ischemia of the outer medulla. Refractory shocked dogs treated with indomethacin also exhibited significantly decreased outer medullary flow. The osmolality of the renal papilla appeared to increase with indomethacin treatment in all three conditions (control, hemorrhage, shock).

Phosphate accumulation by the isolated renal tubule and the effects of parathyroid hormone and cyclic adenosine monophosphate.

The effects of metabolic and transport inhibitors and PTH, cAMP, db-cAMP, and theophylline on Pi uptake by an isolated rat renal tubular preparation has been investigated. Pi uptake by this preparation was a saturable process, was O2- and sodium-dependent, was inactivated by heat=treatment, and was inhibited by dinitrophenol. iodacetate, ouabain, and a decrease in temperature from 37 degrees to 4 degrees C. PTH and cAMP stimulated Pi uptake by energy-dependent and ouabain-inhibitable mechanisms.

Studies on the specificity of immunohistochemical techniques for cyclic AMP and cyclic GMP.

UNLABELLED: Immunohistochemical studies employing antibodies against cyclic nucleotides indicate that cyclic AMP and cyclic GMP are localized to distinct subcellular sites. These antibodies, however, cross-react weakly with noncyclic nucleotides (eg. ATP, GTP), and therefore we investigated the speficity of the immunohistochemical technique. Slides of fetal nuclei exposed to gaseous nitrous acid demonstrated reduced immunofluorescence. The slides were then incubated with cyclic and noncyclic nucleotides, and restoration of distinct cyclic AMP and cyclic GMP staining pattern was achieved only with appropriate cyclic nucleotides. Antibodies that were used have a greater affinity for acetylated derivatives of cyclic nucleotides. By using a gas phase technique, tissue slices were acetylated and immunohistochemical staining intensity was compared with the effect of acetylation on antibody affinity for various nucleotides. Acetylation greatly increased affinity of cyclic AMP antibody for cyclic AMP but not other nucleotides, and greatly intensified cyclic AMP staining. Acetylation moderately increased affinity of cyclic GMP antibody for cyclic GMP, and moderately intensified cyclic GMP staining. CONCLUSION: Both nitrous acid and acetylation studies support the specificity of the immunohistochemical method for cyclic nucleotides.

Renal-resistant hormonoplethoric hypoparathyroidism with evidence for a defective response to cAMP.

A 15.5-yr-old black male is reported with hypocalcemia, hyperphosphatemia, and severe osteitis fibrosa cystica. While hypocalcemic and hyperphosphatemic, the circulating parathyroid hormone (PTH) level and urinary cAMP excretion were increased. An infusion of exogenous PTH produced a normal maximal excretion of urinary cAMP but failed to increase phosphate excretion. Correction of the hypocalcemia by administration of 200,000 U vitamin D daily lowered the endogenous PTH level and basal excretion of cAMP to normal; at that time, infusion of PTH produced both a normal rise in urinary cAMP and a normal phosphaturic response. This pattern of response suggests pseudohypoparathyroidism with a calcium-sensitive defect in renal phosphate transport distal to the PTH receptor adenyl cyclase mechanism, producing hyperphosphatemia, hypocalcemia, and secondary hyperparathyroidism. The osteitis fibrosa cystica was presumably due to the increased PTH, suggesting that resistance to PTH was present in kidney but not bone.

ACTH-secreting medullary carcinoma of the thyroid presenting a severe idiopathic osteoporosis and senile purpura: report of a case and review of the literature.

A 64-yr-old female presented with severe osteoporosis and easy bruisability of over 2-yr duration. Biopsy of a neck mass revealed medullary carcinoma of the thyroid. Subsequently, lymphangitic pulmonary metastases were demonstrated which had been present radiographically for at least 4 yr. Basal serum calcitonin was markedly elevated and increased during calcium infusion. The diagnosis of ectopic ACTH syndrome was first entertained when hypokalemic alkalosis was observed during evaluation of her carcinoma. Elevated urinary 17-hydroxycorticosteroids, 17-ketosteroids, plasma cortisol, and immunoreactive plasma ACTH levels were documented. Adrenal steroidogenesis seemed to suppress on high dose dexamethasone. The primary tumor and its metastases contained high concentrations of immunoreactive ACTH and beta-melanocyte-stimulating hormone. Hepatic metastases contained extremely high concentrations of calcitonin. In contrast to the usual presentation of the ectopic ACTH syndrome as primarily hypokalemic alkalosis and glucose intolerance, patients with relatively benign and indolent ACTH-secreting tumors, such as certain cases of medullary carcinoma of the thyroid, may present with more typical signs and symptoms of Cushing's syndrome. The more pronounced cushingoid features in this latter group presumably reflects a more prolonged period of exposure to elevated glucocorticoid levels. Ten cases of ACTH-secreting medullary carcinoma of the thyroid from the literature are discussed. Extopic ACTH production by such tumors should be considered in the evaluation of patients with Cushing's syndrome or unexplained severe osteopenia.

Role of cyclic 3',5'-GMP in modulation of cellular uptake of phosphate.

The role of cGMP in regulating renal cortical phosphate uptake was investigated in rats. Cyclic GMP (1 mM) produced a 27.7% +/- 1.4 (SE) increase in 32PO4 uptake by isolated renal cortical tubules (P less than 0.001) and cAMP (1 mM) a 28.7% +/- 1.4 increase (P less than 0.001), but their effects were not additive. Acetylcholine (Ach) (1 mM), in the presence of theophylline (T) (10 mM), increased cGMP in cortical slices from 24.1 pmol/g wet wt +/- 1.3 to 76.5 +/- 5.2 (P less than 0.001), but had no effect on cAMP, and Ach (1 mM) in the presence of T (1 mM) increased 32PO4 uptake 19.1% +/- 1.1 (P less than 0.001). Addition of Ca2+ to the incubation medium in the presence of T (10 mM) significantly increased cGMP in cortical slices from 7.4 pmol/g wet wt +/- 0.6 (0 Ca2+ plus EGTA, 0.5 mM) to 24.1 +/- 1.3 (1 mM Ca2+) and caused a 52.2% +/- 2.7 rise in 32PO4 uptake (P less than 0.001). Cyclic AMP was decreased by the addition of Ca2+. In summary, cGMP and cAMP stimulate 32PO4 uptake by renal cortex, and Ach and Ca2+ increase both cGMP and 32PO4 but do not increase cAMP. These data suggest that cGMP may play a role in regulating cellular uptake of phosphate.

The effects of phosphate and vitamin D therapy on osteopenic, hypophosphatemic osteomalacia of childhood.

Two severely osteopenic adolescent males with clinical manifestations of adult onset hypophosphatemic osteomalacia were resistant respectively to physiological and pharmacological doses of vitamin D. Clinical improvement ensued following initiation of pharmacological doses of vitamin D and phosphate. Non-decalcified bone biopsies obtained before and during therapy exhibited correction of an isolated mineralization in the second. The response to treatment was reflected in striking changes in tetracycline-labelled calcification fronts in both patients.