Ultrastructural identification of exocytosis of granules from human gut eosinophils in vivo

Twenty-two percent of 117 biopsies of human intestinal tissues had ultrastructural images of classical regulated secretion from eosinophils in vivo i.e. eosinophil granule extrusion (EGE). Replicate intestinal biopsies that were positive for bacteria had EGE more often than not (p < 0.05); 77% of the isolates were Staphylococci. Some of the intestinal biopsies also had damaged nerves; all that had EGE and damaged enteric nerves also had positive bacterial cultures. The EGE that we observed could not account for all enteric nerve damage, suggesting multifactorial mechanisms for nerve damage in gut tissues. Among the possibilities are release of neurotoxic eosinophil granule proteins by an alternate secretory route, i.e., piecemeal degranulation, direct toxicity of tissue invasive bacteria and/or damaged nerves of unknown etiology such as those that are regularly present in uninvolved tissues of patients with Crohn's disease.

An ultrastructural analysis of tumor-promoting phorbol diester-induced degranulation of human basophils

Release reactions stimulated in human basophils by a variety of secretagogues show biochemical and morphologic differences as well as similarities. Biochemical differences include those of rate, amount, and order of mediator release, as well as mediator type released or generated. Morphologic diversity of release reactions includes prototypic anaphylactic degranulation (AND), or piecemeal degranulation (PMD), and a continuum of anatomic release comprised of PMD followed by AND that is seen when human basophils are stimulated by the bacterial peptide, formyl methionyl leucyl phenylalanine (FMLP). AND is characterized by extrusion of membrane-free granules through multiple plasma membrane pores; PMD is characterized by partially to completely empty, nonfused granule containers in the cytoplasm of basophils. AND is further characterized by diminished-to-absent granules and reduced cytoplasmic vesicles at peak histamine release intervals; PMD does not show decreases in numbers of granules, and cytoplasmic vesicles are plentiful. Smooth membrane-bound vesicles with granule particles and vesicles that appear empty comprise this organelle population. PMD is the single most evident activation change present in basophils that traffic into tissues in multiple diseases in vivo. In this study, we examined the ultrastructural kinetic morphology associated with stimulation of human basophils with tetradecanoyl phorbol acetate (TPA)--a tumor-promoting phorbol diester known to elicit histamine (but not LTC4) release. Partially purified human basophils were prepared for electron microscopy and examined either after control incubations in buffer alone or at 0 time, 1, 2, 5, 10, 30, and 45 minutes after TPA stimulation. Standard morphology and ultrastructural quantitation of vesicles and granules and contents of vesicles or alteration of granules was done and compared with previous ultrastructural kinetic analyses of human basophil release reactions stimulated by different triggers. Like biochemical studies that have determined that TPA is a unique secretogogue for human basophils, the morphology stimulated by TPA and associated with histamine release was also unique. For example, very minor images of AND were evident. Far greater amounts of PMD were imaged. PMD was associated with approximately 50% alteration of cytoplasmic granules by 45 minutes after TPA stimulation. This evidence of empty granules was associated with, and preceded by, a rapid, extensive, and sustained increase in particle-containing cytoplasmic vesicles, as compared with buffer controls (P < 0.001 for each TPA stimulation time compared with unstimulated basophils). In addition, previously undescribed interactions of releasing granules and their overlying plasma membranes characterized TPA-stimulated cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Plasma concentration of furosemide versus specific gravity of urine in predicting dose of administration in race horses

This study was undertaken to determine the applicability of plasma concentration of furosemide and specific gravity (SG) of urine in regulating the use of furosemide administered 4 hours prior to race time in Exercise-Induced Pulmonary Hemorrhage (EIPH) race horses. Nonbleeders (CTL) and certified bleeders (FUR) actively racing in Illinois (IL) and Pennsylvania (PA) were used in the study. Various doses (less than 250, 250, 300, 350, 400 and 500 mg) were administered either as a single intravenous (IV) dose or as a combination (IV-IM) of IV and intramuscular (IM) administrations 4 hours before race time. Plasma and urine samples were obtained post race for determination of furosemide concentration in plasma and measurement of SG of the urine in both CTL and FUR groups. Plasma samples were analyzed for furosemide using High Performance Liquid Chromatography with Fluorescence Detection. SG was measured using a digital refractometer. The results indicate a significant difference (p less than 0.0001) in the SG of the urine samples between the CTL and FUR groups irrespective of the route of administration (IV versus IV-IM). However, SG values of the urine in some CTL samples were lower than those in some FUR samples and vice versa. Thus, the use of SG alone is not reliable for predicting either the dose or the administration of furosemide to race horses. The plasma concentrations of furosemide following the administration (IV) of 250 mg or 500 mg 4 hours prior to race time were indistinguishable (25.91 +/- 4.45 versus 28.12 +/- 6.99 ng/ml, respectively); the majority of the horses in the groups had a plasma concentration of less than 40 ng/ml. When taken in total, plasma concentration of furosemide can only be used as a guide in regulating the administration of furosemide to race horses.

Is type II diabetes mellitus (NIDDM) a surgical disease?

Since February 1, 1980, 515 morbidly obese patients have undergone the Greenville gastric bypass (GGB) operation. Of these, 212 (41.2%) were euglycemic, 288 (55.9%) were either diabetic or had glucose intolerance, and 15 (2.9%) were unable to complete the evaluation. After the operation, only 30 (5.8%) patients remained diabetic (and 20 of these improved), 457 (88.7%) became and have remained euglycemic, and inadequate data prevented classification of the other 28 (5.4%). The patients who failed to return to normal glucose values were older and their diabetes was of longer duration than those who did. The effect of the GGB was not only limited to the correction of abnormal glucose levels. The GGB also corrected the abnormal levels of fasting insulin and glycosylated hemoglobin in a cohort of 52 consecutive severely obese patients with non-insulin-dependent diabetes. The GGB effectively controls weight. If morbid obesity is defined as 100 pounds over ideal body weight, 89% of the patients are no longer "morbidly" obese within 2 years. In most patients, the control of the weight has been well maintained during the 11 years of follow-up; most of the upward creep in weight of 20.8% between 24 and 132 months was from the 49 (9.5%) patients who had staple line breakdowns between the large and small gastric pouches. Non-insulin-dependent diabetes, previously considered a chronic unrelenting disease, can be controlled in the severely obese by the gastric bypass. Whether the correction of glucose metabolism affects the complications of diabetes is unknown. Whether the gastric bypass should be considered for patients with advanced non-insulin-dependent diabetes but who are not severely obese deserves consideration. The GGB has an unacceptably high rate of staple line failure. Accordingly, the authors have recently changed their procedure to one that divides the stomach rather than partitions it with staples.

Ultrastructural immunogold localization of prostaglandin endoperoxide synthase (cyclooxygenase) to non-membrane-bound cytoplasmic lipid bodies in human lung mast cells, alveolar macrophages, type II pneumocytes, and neutrophils

Lipid bodies are non-membrane-bound, lipid-rich cytoplasmic inclusions that occur in many mammalian cell types. Because lipid bodies are more prominent in cells associated with inflammation and are repositories of arachidonyl-phospholipids, a role for lipid bodies in the oxidative metabolism of arachidonic acid to form eicosanoids has been suggested. To evaluate further whether lipid bodies, in addition to serving as non-membranous sources of substrate arachidonate, are involved in eicosanoid formation, we used cells isolated from human lung to investigate the intracellular localization of prostaglandin endoperoxide (PGH) synthase (cyclooxygenase), the key initial, rate-limiting enzyme in the formation of prostaglandins and thromboxanes. Isolated lung cells containing a mixture of mast cells, alveolar macrophages, Type II alveolar pneumocytes, and neutrophils from short-term cultures were fixed in suspension in a dilute aldehyde mixture, post-fixed in osmium tetroxide, stained en bloc with uranyl acetate, dehydrated in a graded series of alcohols, and embedded in Epon. A post-embedding immunogold procedure was used with a primary PGH synthase monoclonal antibody and 20-nm gold-conjugated secondary antibody to demonstrate enzyme locations. Specificity controls were also done. We found PGH synthase in lipid bodies of human lung mast cells, alveolar macrophages, Type II alveolar pneumocytes, and neutrophils. Specific secretory and lysosomal granules and plasma membranes did not express PGH synthase. Specificity controls, including omission of the primary antibody or substitution with an irrelevant antibody, were negative. Absorption of the specific PGH synthase antibody with purified solid-phase PGH synthase resulted in a marked reduction of label in lipid bodies of all four cell types. These findings establish the presence of PGH synthase in lipid bodies of human lung mast cells, alveolar macrophages, Type II alveolar pneumocytes, and neutrophils and, in concert with previous studies, suggest that these cytoplasmic lipid-rich organelles may be non-membrane sites of eicosanoid formation.

Evaluation of LY203647 on cardiovascular leukotriene D4 receptors and myocardial reperfusion injury

In vitro studies have shown LY203647 to be a selective antagonist of contractile responses to leukotriene (LT) D4 and LTE4 in guinea pig ileum, trachea and lung parenchyma. In pithed rat, i.v. injection of LTD4 produced pressor responses that were selectively antagonized by LY203647 in a dose-dependent manner [ED50 7.5 (6.0-9.5) mg/kg, i.v.]. In normal anesthetized rats and dogs, LTD4 reduced aortic blood flow and stroke volume in association with systemic vasoconstriction, variable blood pressure responses and no change in cardiac rate. LTD4 did not alter myocardial contractility corrected for alterations in afterload. Pretreatment of rats and dogs with LY203647 (1-10 mg/kg, i.v.) produced dose-related inhibition of the myocardial and systemic hemodynamic effects of LTD4, whereas coadministration of LY203647 reversed established myocardial depression and systemic and pulmonary vasoconstriction during continuous infusion of LTD4 in dogs. LY203647 (10 mg/kg over 90 min, i.v.) infusion in normal dogs abolished or greatly antagonized hemodynamic responses to LTD4 for 6 hr. In subsequent experiments, myocardial infarct size was measured after 1 hr of occlusion of the circumflex coronary artery and 5 hr of reperfusion. LY203647 (10 mg/kg over 90 min, i.v.) treatment did not alter cardiovascular parameters when compared to time-related alterations observed in control dogs. ST segment deviation and the intensity and duration of cardiac arrhythmias associated with coronary artery occlusion and reperfusion also were similar between groups. Resultant infarct sizes were 46 +/- 1 and 45 +/- 1% of the left ventricular mass placed at risk in control and LY203647-treated dogs, respectively. Present data illustrate the prominent cardiac and systemic hemodynamic effects of LTD4 and indicate that LY203647 produces selective and sustained antagonism of cardiovascular LTD4 receptors. Lack of containment of infarction by LY203647 suggests that endogenous cysteinyl-LT do not contribute to reperfusion injury of ischemic myocardium.

Human gut mucosal mast cells: ultrastructural observations and anatomic variation in mast cell-nerve associations in vivo

One hundred and seventeen coded intestinal biopsy specimens were examined by electron microscopy. All surgical biopsies were obtained from uninvolved sites of patients with two inflammatory bowel diseases (ulcerative colitis or Crohn's disease) and from patients with preneoplastic and neoplastic diseases (adenocarcinoma, rectal polyp, familial polyposis). Biopsy sites included normal ileum, colon, and rectum as well as conventional ileostomies and continent pouches constructed from the ileum. The data reported here describe the ultrastructural anatomy of human gastrointestinal tract mucosal mast cells in vivo and their anatomic associations with enteric nerves.

Ultrastructural evidence for piecemeal and anaphylactic degranulation of human gut mucosal mast cells in vivo

One hundred and seventeen coded intestinal biopsies were examined by electron microscopy and evaluated for morphological evidence of mast cell and basophil secretion in situ. Sixty percent of the biopsies had evidence of secretion. Mast cell secretion was evident in control biopsies, many of which were obtained from uninvolved tissues of patients with inflammatory bowel disease. Biopsies of inflamed continent pouches from ulcerative colitis (UC) patients showed more mast cell secretion than noninflamed UC pouch biopsies. This evidence of mast cell secretion supports recent work that documents high constitutive levels of histamine in jejunal fluids of Crohn's disease patients and suggests a proinflammatory role for mast cells in inflammation associated with pouchitis.

Effects of short-term isolation on the locomotor activity of the angelfish (Pterophyllum scalare)

Two experiments were conducted to test in angelfish (Pterophyllum scalare) some implications of Gallup and Suarez's (1980) ethological model of open-field behavior and to differentiate between the initial locomotor effects of a novel environment and those of isolation per se. Juveniles placed alone in a novel environment initially showed increased locomotion compared with their previous level when kept as a group and with that of fish placed in the novel environment in groups of three and five. When placed alone in a novel tank, individuals that had already been isolated for 10 days moved about less than those that had been isolated for 4 days. During isolation, angelfish significantly reduced activity to a minimum after 3 to 4 days, and after 10 days the level was still lower than in the group situation. The results suggest that, in addition to birds and rodents, Gallup and Suarez's model is applicable to fish and may account for the effects of longer exposure to a novel environment.

Impact of chromosomal translocations on prognosis in childhood acute lymphoblastic leukemia

The presence of a chromosomal translocation in the leukemic cells at diagnosis of acute lymphoblastic leukemia (ALL) in children is associated with a high risk for treatment failure. We have reexamined the relationship between translocations and prognosis in 146 children with ALL who received risk-based therapy such that high-risk patients were treated with intensive drug schedules. In univariate analysis, multiple factors were associated with a relatively poor event-free survival (EFS) including age less than 2 years or greater than 10 years (combined group), WBC count greater than 10 x 10(9)/L, French-American-British (FAB) morphologic classification L2, absence of common ALL antigen (CALLA, CD10) expression, absence of hyperdiploidy with a chromosome number of 50 to 60, and presence of the specific translocations t(4; 11)(q21;q23) or t(9;22)(q34;q11) (combined group). However, there was no disadvantage with respect to EFS in patients with translocations compared with those who lacked translocations (73% at 4 years in both groups). Furthermore, when patients with specific cytogenetic abnormalities for which the prognostic significance has been well established (hyperdiploid 50 to 60, t(4;11), and t(9;22] were removed from the analysis, the remaining group with other translocations had a better EFS than the remaining group lacking translocations, although this was not statistically significant (81% v 65% at 4 years, P = .24). In a multivariate analysis, a model including WBC count and FAB classification was the strongest predictor of EFS. The presence or absence of translocations was not an independent predictor of EFS and did not contribute to the ability of any model to predict EFS. In conclusion, when effective intensive therapy is used to treat childhood ALL with high-risk clinical features, categorization of patients on the basis of chromosomal translocations without attention to the specific abnormality is not useful as a prognostic factor.

Craniofacial suture stenosis: morphologic effects

Craniofacial anomalies, such as Apert's and Crouzon's syndromes, are presumed to be related to premature growth arrest of cranial base growth sites. However, premature growth arrest at cranial vault sutures in animals appears to play a causative role in the development of cranial deformities characteristic of single-suture, or simple, craniosynostosis in humans. To study the possible causative role of cranial vault and other (interface) suture stenoses on the development of craniofacial deformity, a vault suture and an interface suture between the cranial vault and facial skeleton were simultaneously immobilized. Thirty-one New Zealand White rabbits at 9 days of age underwent implantation of dental amalgam growth markers adjacent to cranial vault and facial sutures. In the experimental group (n = 15), methylcyanoacrylate adhesive was applied over the coronal (vault) and frontonasal (interface suture between vault and facial skeleton) sutures to immobilize them. The remaining 16 animals served as sham-treated controls. All animals underwent serial radiographic cephalometry to document growth effects in the cranial vault, cranial base, and facial skeleton. Application of adhesive resulted in statistically significant (p less than 0.05) reduction in growth at the coronal and frontonasal sutures. This was accompanied by an overall significant reduction in neurocranial vault length during the first 30 days of development.(ABSTRACT TRUNCATED AT 250 WORDS)

An appraisal of tidal activity rhythms

Organisms of the marine littoral zone experience a much wider range of periodicities in their environment than do their terrestrial counterparts. Tidal cycles of semidiurnal, diurnal, lunar, and semilunar frequencies may all recur at the same locality, in addition to the diel cycle of light and darkness. The relationship of endogenous activity patterns to the prevailing geophysical variables thus poses problems for the temporal organization of the organism. The way in which intertidal animals synchronize their behaviour and physiology to such a diversely fluctuating environment, and the efficacy of different environmental factors as entraining agents is considered. Evidence pertaining to the endogenous control mechanisms, both physiological and behavioural, is reviewed, and the organization of the endogenous time-keeping system discussed in terms of identifiable oscillators of different frequencies.

Child sexual abuse sequelae and body-image surgery

Child sexual abuse is common and damages the body image. Child sexual abuse survivors may request body-image surgery. Seven patients are described in whom child sexual abuse sequelae complicated body-image surgery. Two patients viewed their surgeons as similar to sexual abusers. Yet two patients were clearly, and two possibly, helped by the surgery. Surgeons can detect and manage such patients by (1) having a child sexual abuse therapist on hand for consultation, (2) adding "abuse" to the medical history form, (3) recommending to known or suspected child sexual abuse patients preoperative therapy or a self-help book, (4) obtaining specific permission for any body contact, (5) stating belief in abuse, if revealed, (6) explaining the surgery in unusual detail, (7) recognizing the high-risk child sexual abuse groups, and, (8) declining to operate on the angry child sexual abuse patient.

Haemothorax caused by a solitary costal exostosis

A case of spontaneous haemothorax in a 14 year old boy due to trauma to the diaphragm caused by a solitary benign growth (exostosis) of a rib is described.

Cloning and pretranslational hormonal regulation of testosterone 16 alpha-hydroxylase (P-45016 alpha) in male rat liver

cDNA clones for P-45016 alpha were isolated from a male liver lambda gt11 expression library using antibodies against P-45016 alpha. The clones encompassed 1633 and 1791 bp, respectively. The latter clone contained the whole coding sequence. The 20 deduced NH2-terminal amino acids were identical to those of P-450h and the cDNA sequence was in complete agreement with that of P-450 (M-1). Northern blots showed that P-45016 alpha in the rat liver is pretranslationally regulated by the growth hormone secretory pattern. Southern blots indicated that few genes belong to the same P-450 gene family as P-45016 alpha.

Variant translocations (9;11): identification of the critical genetic rearrangement

The t(9;11)(p22;q23) is a recurring abnormality in acute nonlymphocytic leukemia. The analysis of complex 9;11 translocations will aid in the identification of the conserved chromosomal junction or the critical genetic alteration created by the rearrangement; however, variant translocations involving chromosomes #9 and #11 have not been reported. We have identified such variants in two patients who had acute myelomonocytic leukemia and acute monocytic leukemia, characterized by a t(9;11;18)(p22;q23;q12) and a t(9;11;13)(p22;q23;q34), respectively. The conserved junction resulting from these rearrangements is created by the translocation of chromosomal material from 9p to 11q.

Chemotherapy-related toxicity in infants treated according to the Second National Wilms' Tumor Study

Babies under 12 months of age have been included in the National Wilms' Tumor Study (NWTS) series of clinical trials. Undue chemotherapy-related toxicity was encountered early during the course of the second NWTS. The prescribed doses of actinomycin D (AMD), vincristine (VCR), and Adriamycin ([ADR] doxorubicin; Adria Laboratories, Columbus, OH) were therefore halved. The frequency of severe hematologic toxic episodes was reduced (30 of 64 or 47% for babies receiving full doses [FD], and six of 48 or 13% for those given reduced doses [RD]). Similar reductions in pulmonary and hepatic effects were noted, and treatment-related deaths were reduced from 6% to 0 for the FD and RD samples, respectively. These frequencies among RD babies were similar to those encountered in 530 older children administered FD. Reduction of dose did not compromise therapeutic effectiveness.

Rapid microwave fixation of rat mast cells. I. Localization of granule chymase with an ultrastructural postembedding immunogold technique

We defined the ultrastructural localization of chymase in rat peritoneal mast cells using standard aldehyde fixation and a newly described microwave fixation method (Login GR, Dvorak AM: Microwave energy fixation for electron microscopy. Am J Pathol 120: 230, 1985; Login GR, Stavinoha WB, Dvorak AM: Ultrafast microwave energy fixation for electron microscopy. J Histochem Cytochem 34:381, 1986) and postembedding immunogold labeling. Thin sections were exposed first to goat IgG anti-rat chymase and second to gold-conjugated rabbit Ig directed against goat IgG. By transmission electron microscopy, gold particles were localized to the matrix of cytoplasmic granules. Control sections treated with nonimmune sera did not exhibit labeling of mast cells. Thin sections treated simultaneously with purified rat mast cell chymase and anti-chymase antibody in competition studies, showed a marked reduction in granule staining. These findings demonstrate that a microwave fixation method can be used to rapidly fix cell suspensions for postembedding immunocytochemical studies.

Interaction between adrenergic and cholinergic nerve terminals in the urinary bladder of rabbit, cat and man

The influence of muscarinic receptor stimulation (carbachol) and blockade (scopolamine) on the release of 3H-labelled noradrenaline from adrenergic neurons was investigated in isolated detrusor preparations from rabbit, cat and man. A significant influence on the release of 3H from adrenergic nerve terminals was found in the three species with a concentration-dependent decrease and increase induced by carbachol and scopolamine, respectively. Using the alpha 2-adrenoceptor stimulating and blocking agents clonidine and rauwolscine in rabbit and human detrusor preparations, the presence of prejunctionally located inhibitory alpha 2-adrenoceptors could also be demonstrated. The findings indicate the possibility of a functionally important interaction between cholinergic and adrenergic nerves in the urinary bladder mediated via inhibitory muscarinic receptors on adrenergic nerve terminals.

Effects of calcium, calcium channel blockers and Bay K 8644 on contractions induced by muscarinic receptor stimulation of isolated bladder muscle from rabbit and man

In isolated bladder smooth muscle from both rabbit and man, carbachol-induced contractions were reduced by the calcium channel blocker nifedipine, whereas the calcium channel promotor Bay K 8644 had no effect. In nominally calcium-free medium containing 10(-4) M EGTA, carbachol-induced contractions were reduced by 69% (rabbit) and 87% (man). These contractions were abolished by nifedipine, whereas Bay K 8644 significantly increased their amplitude, in rabbit preparations almost to control level. Electrical field stimulation produced contractions which could be suppressed by scopolamine by about 50% (rabbit) and more than 90% (man). These contractions were abolished by calcium-free medium (10(-4) M EGTA), suppressed by nifedipine, but significantly enhanced by Bay K 8644. The depressant effects of nifedipine, verapamil and diltiazem were reversed by Bay K 8644. The calcium channel blockers relaxed K+-induced contractions to base line, and this action was counteracted by Bay K 8644, less effectively when relaxations were induced by diltiazem. It is concluded that contractions produced by muscarinic receptor stimulation are primarily dependent on calcium bound to the outside of the membrane of the smooth muscle, and/or coming from the extracellular medium. Electrically evoked, scopolamine sensitive contractions seem to be mediated by a mechanism different from that of contractions produced by exogenously added muscarinic receptor agonist. The present data support the view that combined blockade of muscarinic receptors and calcium channels is an effective way of inhibiting bladder contractions in both rabbit and man.

Effects of acetylethylcholine mustard on [3H]quinuclidinyl benzilate binding and acetylcholine release in rat brain synaptosomes

The effects of acetylethylcholine mustard and its aziridinium derivative (AMMA) on acetylcholine (ACh) release and [3H]quinuclidinyl benzilate (QNB) binding were studied in rat cortical synaptosomes. After incubation for 5 min at 37 degrees C, AMMA reduced [3H]QNB binding with an IC50 of 9 microM. Following incubation for 5 min with 50 microM AMMA and washing, there was a 62% reduction in the [3H]QNB binding capacity with no change in the KD value for the remaining receptors, a result indicating the irreversibility of the AMMA binding. AMMA and oxotremorine both reduced the basal and 30 mM K+-induced release of newly synthesized [3H]ACh in dose-dependent manners over a 2.5-min period. At identical 50 microM concentrations, AMMA produced a much longer inhibition of basal [3H]ACh release than oxotremorine did. The inhibition of basal and 30 mM K+-induced [3H]ACh release by AMMA (10-250 microM) was blocked by 2 microM atropine during a 2.5-min release incubation, but not during a 30-min release incubation. After synaptosomes were treated with 50 microM AMMA for 5 min and the unbound drug was washed out from the tissue, [3H]ACh release (basal and K+-induced) was reduced. AMMA (50 microM) reduced high-affinity choline uptake and ACh synthesis by greater than 90% in this tissue, but these effects did not account for the [3H]ACh release inhibition, because they were not atropine sensitive and hemicholinium-3 had no effect on [3H]ACh release under the conditions used in these studies, i.e., after extracellular [3H]choline was washed out. Taken together, these results suggest that AMMA may be an irreversible agonist at presynaptic muscarinic autoreceptors.

Effects of AF64A on [3H]acetylcholine synthesis in neuron-enriched primary brain cell cultures

[3H]Acetylcholine (ACh) synthesis was measured in primary neuronal cultures from neonatal rat brains. Neuronal [3H]ACh synthesis was blocked by hemicholinium-3 and depended on the age of the cultures, increasing for ca. 10 days, and eventually declining. The irreversible inhibitor AF64A (10 or 30 microM) inhibited [3H]ACh synthesis from [3H]choline at concentrations (10 or 30 microM) with affecting choline acetyltransferase activity. Nine-day-old cultures recovered 90% of their [3H]ACh synthesis within 7 days after AF64A, while 13-day-old cultures never recovered. These results suggest that the turnover of neuronal choline transporters is age-related.

The mechanisms of iron uptake by fetal rat hepatocytes in culture

The mechanisms of iron accumulation by cultured hepatocytes isolated from fetal rat liver (19 days gestation) were investigated using rat transferrin labeled with 125I and 59Fe. The rates of iron and transferrin internalization by the cells were measured by incubating the hepatocytes with the labeled transferrin at 37 degrees C followed by treatment with pronase at 4 degrees C to remove surface-bound transferrin and iron. Iron internalization increased linearly with time. Approximately 65% of the internalized iron was incorporated into ferritin. In contrast to iron, the rate of transferrin internalization was biphasic, with a rapid phase during the first 10 to 15 min and a second slower phase which becomes more apparent after that time. Iron and transferrin internalization were temperature-dependent. Chase experiments showed that the internalized transferrin donated all of its iron to the cell and was then released in a biphasic manner which was dependent on the time of preincubation with radiolabeled transferrin. These experiments showed that iron uptake occurs by at least three processes. The first mechanism involves the specific receptor-mediated endocytosis of transferrin. Each cell has an average of 7.8 +/- 1.0 X 10(5) (mean +/- SE, n = 5) transferrin binding sites with an apparent association constant of 2.0 +/- 0.4 X 10(6) M-1. The second process is nonsaturable up to a transferrin concentration of at least 6 microM but like the specific process, also leads to accumulation of iron in excess of transferrin. It involves the endocytosis of transferrin mediated by 4.2 X 2.6 X 10(5) M-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Heme inhibits transferrin endocytosis in immature erythroid cells

The inhibitory effect of heme on iron uptake from transferrin by rat and rabbit reticulocytes and erythroid cells from the fetal rat liver was studied in vitro. Addition of hemin was shown to cause a decrease in the rate of transferrin endocytosis, the degree of inhibition being proportional to the reduction in iron uptake. The heme synthesis inhibitors, isoniazid and succinylacetone, stimulated the rate of transferrin endocytosis by 15-30% and caused a proportional increase in the rate of iron uptake, possibly by reducing the intracellular free heme concentration. It is concluded from these results that heme affects iron uptake by influencing the rate of transferrin endocytosis and recycling.

Treatment of patients with metastatic osteogenic sarcoma: a report from the Children's Cancer Study Group

Fifty-three patients with metastatic osteogenic sarcoma were treated with vincristine, high-dose methotrexate with citrovorum factor rescue, and cisplatin. Metastases were surgically removed in most patients, either prior to chemotherapy or following initial response to therapy. Among 29 previously treated patients, responses to initial chemotherapy included two complete remissions, six partial remissions, and eight patients with stable disease. Twenty-three patients were disease-free, six for greater than 12 months. Toxicity was moderate, but usually reversible. There were two toxic deaths and one unexplained death 48 hours following a dose of cisplatin.

Cell markers in lymphoma syndrome leukemia in children: a pilot study

Children with acute lymphocytic leukemia (ALL) who have a "lymphoma syndrome" (LySLk) defined by the presence of at least three of the following criteria: a) Hg greater than 10 g/dl, b( lymph nodes greater than 3 cm, c) spleen below umbilicus, d) liver below umbilicus, and e) mediastinal mass, appear to represent a subgroup of ALL. These children have a poor prognosis for survival when treated with standard chemotherapy for ALL. We performed a retrospective review of 21 patients at Children's Memorial Hospital with LySLk diagnosed from Jan 24, 1977 to July 8, 1981 and of the surface markers on their leukemic cells at diagnosis. Surface markers identified included E-rosettes (E), surface immunoglobulin (Slg), and common ALL antigen (cALLA). Four patients were cALLA positive and E-rosette negative; nine patients were E-negative, cALLA negative; six patients were E positive, cALLA negative. In two patients E-rosettes could not be accurately determined because of a low percentage of lymphoblasts in the samples studied. Follow-up data on cALLA-positive and cALLA-negative patients revealed 4/4 cALLA-positive patients with no evidence of disease (NED) at 22 + to 45 + months from diagnosis and 2/16 cALLA-negative patients NED at 19 + and 57 + months. Thus it appears that the majority of children with LySLk have lymphoblasts which are cALLA negative. Patients who meet clinical criteria for LySLk but whose surface markers are E negative, cALLA positive may have a better prognosis and may represent a separate subgroup of patients with ALL and, therefore, should be given therapy appropriate for their prognostic classification by more standard criteria, such as white blood count, age, and sex.

Rhythms of locomotion and oxygen consumption in the estuarine amphipod Corophium volutator (Crustacea: Amphipoda)

The estuarine amphipod Corophium volutator exhibits an endogenous circatidal rhythm of swimming activity, with maxima occurring just after the expected time of high water, under constant laboratory conditions. Oxygen uptake by Corophium is also subject to modulation across the tidal cycle. The period of highest oxygen uptake occurs during the ebb tide, in phase with the period of maximum swimming activity. A second increase in oxygen uptake during the early flood tide is thought to reflect either in-burrow activity or a previously described rhythm of emergence. This being so, this aspect of the animal's respiratory metabolism may be regulated by an autonomous oscillator independent of that governing the animal's swimming behaviour.

Coagulopathy of disseminated neuroblastoma

We performed coagulation studies in 16 patients with advanced neuroblastoma. Four of these patients had major hemorrhagic or thromboembolic complications. Abnormal coagulation screening tests were seen in all patients with active metastatic disease. We also measured plasma fibrinopeptide A, a sensitive measure of intravascular thrombin generation. Increased concentrations of fibrinopeptide A were found in each patient studied with active metastatic disease. Coagulopathy is a frequent finding in metastatic neuroblastoma and may cause severe morbidity. Laboratory studies suggesting either hyper- or hypocoagulability are frequent findings.

A comparison between cyclosporin A and methylprednisolone plus azathioprine on bronchial healing following canine lung autotransplantation

The effects of two low-dose immunosuppressive therapies upon the healing of the bronchial anastomosis and skin wounds following lung autotransplantation were evaluated. Autotransplantation was performed in three groups of dogs: Group 1 (nine dogs) received no immunosuppression, Group 2 (seven dogs) received postoperative immunosuppression with methylprednisolone (2 mg/kg) and azathioprine (1.5 mg/kg), and Group 3 (four dogs) received postoperative immunosuppression with cyclosporin A (20 mg/kg/day). Skin incisions 7 cm in length were made in the dorsal region of each dog. Dogs were put to death 23 days postoperatively, and the breaking strength of the bronchial anastomoses and skin wounds was evaluated with the Instron Universal Testing Machine, with a cross-head speed of 0.5 cm/min. Bronchial breaking strengths were similar in Groups 1 and 3 and significantly higher than in Group 2 (p less than 0.001). Skin breaking strengths were similar in Groups 1 and 3 and significantly higher than in Group 2 (p less than 0.001). Scanning electron microscopic (SEM) studies of both skin and bronchial wounds showed normal formation of collagen bundles in Groups 1 and 3 but a disorganized pattern in Group 2. Our results suggest that low-dose immunosuppression with methylprednisolone and azathioprine significantly affects wound healing and breaking strength of both bronchial anastomoses and healed skin incisions following canine lung autotransplantation. Immunosuppression with cyclosporin A had no adverse effect on either bronchial or skin healing.

Thromboxane synthesis by sources other than platelets in association with complement-induced pulmonary leukostasis and pulmonary hypertension in sheep

Infusion into sheep of plasma containing zymosan-activated complement produces leukopenia, pulmonary leukostasis, and pulmonary artery hypertension. We previously demonstrated a close relationship between the pulmonary vascular response and elevations of plasma thromboxane. We have investigated the source of thromboxane synthesis in this model. Plasma containing zymosan-activated complement added to whole blood did not stimulate thromboxane synthesis. This observation suggested that leukocytes do not synthesize thromboxane directly in response to complement added to whole blood did not stimulate thromboxane synthesis. This observation suggested that leukocytes do not synthesize thromboxane directly in response to complement. Sheep rendered severely thrombocytopenic by the administration of antiplatelet serum responded to complement infusion in the usual way. Pretreatment with aspirin (10 mg/kg) protected sheep against the pulmonary vascular response and completely blocked thromboxane synthesis. Transfusion of functional platelets did not restore these responses. Twenty-four hours after aspirin treatment, in vivo thromboxane synthesis was significantly greater than platelet thromboxane synthesis in vitro. Thromboxane is synthesized by a tissue which recovers cyclooxygenase enzyme activity at a rate that is more rapid than platelet turnover. Sheep lung synthesizes thromboxane actively in vitro. It is postulated that leukocytes exposed to activated complement components damage pulmonary vascular endothelial cells and stimulate synthesis of thromboxane A2 which causes pulmonary vasoconstriction.

Psychosocial aspects of pediatric leukemia: from diagnosis through the first six months of treatment

Newly diagnosed children with leukemia and their families were subjects of a longitudinal study to describe coping behaviors, to determine adequacy of coping, and to discover predictors of healthy coping with leukemia. Families were followed for six months during which time they were interviewed, completed tests and scales, and were rated by physicians, nurses, and psychosocial staff. Families showed a wide variety of reactions and coping behaviors. The data supported the hypothesis that most families cope well despite the stresses of the first six months post-diagnosis. Based on physicians' ratings, psychosocial intervention appeared to be effective for mothers during the early outpatient phase of treatment. Age of child, previous coping, coping of other family members, a good support system, and lack of additional stresses were significantly correlated with healthy coping. The need for longitudinal assessment of coping was stressed.