Extraction of Phospholipids from Human Erythrocyte Membranes by Hemoglobin Oxidation Products.

This investigation examines oxidation conditions under which hemoglobin extracts membrane phospholipid from erythrocytes and model membranes. In erythrocytes made echinocytic with exogenous phospholipid, addition of hemoglobin oxidized with hydrogen peroxide (H2O2) or Vitamin C (conditions that result in the formation of significant quantities of choleglobin), but not ferricyanide (which produces predominantly methemoglobin), induced dose-dependent shape reversion to less echinocytic forms, consistent with extraction of phospholipids from the exofacial side of the membrane. Erythrocytes preloaded with radiolabeled phosphatidylcholine or NBD-labeled phosphatidylcholine, phosphatidylglycerol or phosphatidic acid, exhibited greatest extraction of radiolabel or fluorescence signal with exogenous hemoglobin oxidized via H2O2 or Vitamin C, but not ferricyanide. However, with NBD-phosphatidylserine (a preferential inner monolayer intercalator), significantly less extraction of labeled lipid occurred with oxidized hemoglobin prepared under all three oxidizing conditions. In dimyristoylphosphatidylcholine liposomes containing radiolabeled phosphatidylcholine, phosphatidylserine or phosphatidylethanolamine, subsequent addition of hemoglobin oxidized with H2O2 or Vitamin C extracted radiolabeled lipid with significantly greater efficiency than ferricyanide-treated hemoglobin, with enhanced extraction detectable at levels approaching physiological plasma oxidant concentrations. Radiolabeled lipid extraction was comparable for phospholipids containing saturated acyl chains between 12 and 18 carbons but diminished significantly for oleoyl-containing phospholipids. Hemoglobin dimerization occurred at very low levels with H2O2 treatment, and even lower levels with Vitamin C treatment, and thus did not correlate to the high efficiency and consistent levels of lipid extraction observed with these treatments. These findings indicate that choleglobin extracts lipids from cell membranes regardless of headgroup or acyl chain length, through a process of direct hydrophobic interaction with the membrane surface.

Neoadjuvant imatinib for borderline resectable GIST.

A 36-year-old woman presented to the emergency department with black stools and syncope. Her hemoglobin was 7.0 and her red blood cells were microcytic. Upper endoscopy did not identify a clear source of bleeding, but a bulge in the third portion of the duodenum was noted. A CT scan showed a large extraintestinal mass, and follow-up esophagogastroduodenoscopy/endoscopic ultrasound with biopsy revealed a spindle cell neoplasm, consistent with gastrointestinal stromal tumor (GIST). Because of the size of the lesion and association with the superior mesenteric vein and common bile duct, she was referred to medical oncology for consideration of neoadjuvant imatinib. Neoadjuvant tyrosine kinase inhibitor therapy for GISTs is emerging as a viable treatment strategy for borderline resectable tumors, although the dose, duration, and optimal imaging modalities have not been clearly established. Recent pathologic and radiographic data have provided insight into the mechanism and kinetics of this approach. This case report presents a patient for whom surgery was facilitated using neoadjuvant imatinib.

A PHASE IIA STUDY REPOSITIONING DESIPRAMINE IN SMALL CELL LUNG CANCER AND OTHER HIGH-GRADE NEUROENDOCRINE TUMORS.

BACKGROUND: A bioinformatics approach identified antitumor effects of tricyclic antidepressants (TCAs) in small cell lung cancer (SCLC) and other high-grade neuroendocrine carcinomas (grade 3 neuroendocrine carcinomas) (G3NEC) that was subsequently validated in preclinical models with a putative mechanism of action via inhibition of neuroendocrine signaling pathways. This study was undertaken to reposition the candidate TCA desipramine in a clinical trial in SCLC and G3NEC. METHODS: In this prospective, phase IIa intrapatient dose escalation clinical trial, patients were required to have failed at least one prior chemotherapy for metastatic SCLC or G3NEC. Treatment with desipramine began at 75 mg nightly with escalation in increments of 75 mg weekly to a maximum of 450 mg daily. RESULTS: Six patients were enrolled, 3 with SCLC, and 3 with G3NEC (lung, rectal, and pancreas). Tolerability of desipramine was worse than predicted. Of the 6 patients enrolled: 1 patient achieved 300 mg daily, 2 patients reached 150 mg daily, 1 patient reached 75 mg daily, and 2 patients were unable to tolerate any stable dose. Reasons for discontinuation included drug-related grade 3 colon pseudo-obstruction, unrelated GI bleed, and grade 1-2 neurocognitive adverse events. Median clinical or radiographic progression free survival was 1.2 months (range 0.2-3.3) and median overall survival from study entry was 2.7 months (range 1.3-5.6). CONCLUSIONS: No clinical or radiographic benefit was observed using desipramine to treat SCLC and G3NEC, so this trial was terminated. Intolerable low and medium grade neurocognitive side effects led to intermittent treatment and early discontinuation in most patients; given this limitation, doses achieved may be inadequate compared to the preclinical studies. MICROABSTRACT: A bioinformatics approach previously identified a potential antitumor effect of tricyclic antidepressants (TCAs) in small cell lung cancer (SCLC) and other high-grade neuroendocrine carcinomas (grade 3 neuroendocrine carcinoma) (G3NEC), which was validated in preclinical models. In this prospective, phase IIa clinical trial, patients were required to have failed at least one prior chemotherapy for metastatic SCLC or G3NEC (Ki-67 ≥ 20% or ≥ 20 mitoses/10 HPF). Treatment with desipramine began at 75 mg nightly with escalation by 75 mg weekly to a maximum dose of 450 mg daily. Six patients were enrolled on this clinical trial, 3 with SCLC, and 3 with G3NEC (lung, rectal, and pancreatic). Tolerability of desipramine was worse than predicted. In the 6 patients enrolled: 1 patient achieved 300 mg daily, 2 patients reached 150 mg daily, 1 patient reached 75 mg daily, and 2 patients were unable to tolerate any stable dose. Reasons for discontinuation included drug-related grade 3 colon pseudo-obstruction, unrelated GI bleed, and grade 1-2 drug related dizziness, confusion, and somnolence. Though numbers are small, median clinical or radiographic progression free survival was 1.2 months (range 0.2-3.3) and median overall survival from study entry was 2.7 months (range 1.3-5.6). Although preclinical evidence was promising, no clinical or radiographic benefit was observed using desipramine to treat SCLC and G3NEC, so this trial was terminated.

Stratified distribution of synapses in the inner plexiform layer of primate retina.

Distributions of bipolar (B) and amacrine (A) synapses and postsynaptic ganglion cell (G) dendritic profiles in the inner plexiform layer (IPL) were analyzed in EM montages of monkey central and human foveal and peripheral retinae. Synapses and profiles were counted and plotted for each 5% interval of IPL, with 0% at the inner edge of the inner nuclear layer and 100% at the outer edge of the ganglion cell layer. In monkey and human retinae, both A and B synapses occur throughout the IPL, but the ratio of A to B synapses varies from 2:1 to more than 6:1. In the monkey central retina, four bands of A conventional synapses are concentrated at 15, 35, 60, and 80% depth. In the human foveal slope, there are two main A bands at 45 and 85%, whereas in the human periphery, there are five bands at 15, 35, 60, 75, and 90%. In both species, A processes containing large dense-core vesicles are concentrated in three bands at 10-20, 50, and 80-90% depth, corresponding to previously described levels of peptides, dopamine, and GABA. B ribbon synapses are distributed fairly evenly throughout the IPL, with a suggestion of four broadly overlapping bands. Most B ribbons are presynaptic to one A and one G (B----A/G). In the human, there are significantly more B dyads with postsynaptic G's (B----A/G, B----G/G) in the fovea (91%) than in the periphery (66%), implying greater A cell processing peripherally. Also in the human, B terminals containing glycogenlike granules are concentrated in the outer half of the IPL, with agranular terminals in the inner half. Our results demonstrate multiple strata containing different types of synaptic contacts in primate IPL.

The retinal projection to the cat pretectum.

Retinal ganglion cells were labeled retrogradely by localized injections of HRP into different regions of the pretectum, tectum, and optic tract in 26 cats. Retinal projection zones in the pretectum were labeled anterogradely in the same cats by intravitreal injections of 3H-proline. This allowed the HRP injection sites to be located with respect to the retinal termination zones. The form of the projection zones from retina to pretectum was determined from serial reconstructions of either coronal or horizontal sections. The zones are best distinguished in horizontal sections, where they are seen as four roughly parallel strips on either side of the brain. They are more-or-less parallel to the anterior border of the tectum, and appear to traverse the entire width of the retinal projection to the tectum. Each zone is similar in form for the ipsilateral and contralateral projections, although the contralateral projection is thicker and denser. Binocular injections of 3H-proline showed that the projections from the two eyes were in register and did not interdigitate. Cells labeled by HRP injections in the anteromedial end of the pretectum were concentrated in the lower nasal quadrant of the contralateral retina, and the lower temporal quadrant of the ipsilateral retina. Posterolateral injections labeled cells in the upper quadrants. There is thus a rough retinotopic mapping along the elongated axis of the pretectum. When the distributions of ganglion cells labeled by HRP injections to different parts of the pretectum are combined, they show a concentration in both the visual streak and area centralis, and thereby reflect, at least qualitatively, the relative spatial distribution of the entire ganglion-cell population. About 85% of the retinal projection to the pretectum is contralateral. For all of the HRP injections, the spatial density of labeled cells was always low, accounting for no more than 3% of the total spatial density of ganglion cells in any retinal region. Several types of ganglion cells were labeled following injections to most regions of the pretectum; these included alpha, beta, and epsilon cells, as well as small-bodied cells showing a variety of morphologic forms. Alpha cells were labeled mainly from the anterolateral end of the pretectum, but other cell types were labeled from all injected regions. In the peripheral retina, 2% of the labeled cells were alpha cells, 32% were beta cells, 19% were epsilon cells, and the remaining 47% were small cells whose dendrites only occasionally filled to any significant extent.(ABSTRACT TRUNCATED AT 400 WORDS)

Localization of glycine-containing neurons in the Macaca monkey retina.

Autoradiography following 3H-glycine (Gly) uptake and immunocytochemistry with a Gly-specific antiserum were used to identify neurons in Macaca monkey retina that contain a high level of this neurotransmitter. High-affinity uptake of Gly was shown to be sodium dependent whereas release of both endogenous and accumulated Gly was calcium dependent. Neurons labeling for Gly included 40-46% of the amacrine cells and nearly 40% of the bipolars. Synaptic labeling was seen throughout the inner plexiform layer (IPL) but with a preferential distribution in the inner half. Bands of labeled puncta occurred in S2, S4, and S5. Both light and postembedding electron microscopic (EM) immunocytochemistry identified different types of amacrine and bipolar cell bodies and their synaptic terminals. The most heavily labeled Gly+ cell bodies typically were amacrine cells having a single, thick, basal dendrite extending deep into the IPL and, at the EM level, electron-dense cytoplasm and prominent nuclear infoldings. This cell type may be homologous with the Gly2 cell in human retina (Marc and Liu: J. Comp. Neurol. 232:241-260, '85) and the AII/Gly2 of cat retina (Famiglietti and Kolb: Brain Res. 84:293-300, '75; Pourcho and Goebel: J. Comp. Neurol. 233:473-480, '85a). Gly+ amacrines synapse most frequently onto Gly- amacrines and both Gly- and Gly+ bipolars. Gly+ bipolar cells appeared to be cone bipolars because their labeled dendrites could be traced only to cone pedicles. The pattern of these labeled dendritic trees indicated that both diffuse and midget types of biopolars were Gly+. The EM distribution of labeled synapses showed Gly+ amacrine synapses throughout the IPL, but these composed only 11-23% of the amacrine population. Most of the Gly+ bipolar terminals were in the inner IPL, where 70% of all bipolar terminals were labeled. These findings are consistent with previous data from cats and humans and suggest that both amacrine and bipolar cells contribute to glycine-mediated neurotransmission in the monkey retina.

GABA-immunoreactive profiles provide synaptic input to the soma, axon hillock, and axon initial segment of ganglion cells in primate retina.

GABA-immunoreactive displaced amacrines were previously shown to make synapses onto neuronal profiles in the ganglion cell layer (GCL) of macaque monkey retina [Koontz, Hendrickson and Ryan (1989) Visual Neuroscience, 2, 19-25]. These postsynaptic elements have been investigated further using postembedding immunogold methods for electron microscopy. This paper provides ultrastructural evidence that GABA-immunoreactive profiles are presynaptic to the ganglion cell soma, axon hillock, and axon initial segment in the GCL and its border with the nerve fiber layer (NFL). Some axonal profiles have a dense undercoat and fasciculated microtubules, features that are characteristic of the axon initial segment in many neurons of both central and peripheral nervous systems. These features are confined to small- and medium-diameter (0.2-0.6 microns) axon profiles located near the GCL/NFL border and are not found on axonal profiles lying deep in the NFL, suggesting that the dense-coated region does not extend far along the axon and that the dense-coated region may be narrower than the distal part of the axon. The dense-coated region may correspond to the ganglion cell "narrow segment" recently described in a variety of species using light microscopic methods. The results presented here strengthen our previous hypothesis that GABA-immunoreactive neurons in the GCL provide direct synaptic input to ganglion cells near the site of action potential initiation.

Immunocytochemical localization of GABA and glycine in amacrine and displaced amacrine cells of macaque monkey retina.

Recent studies have varied widely in the percentages of GABA- and glycine-immunoreactive (GABA+, GLY+) amacrines reported for primate retina. We compared the distributions of GABA+ and GLY+ amacrines and displaced amacrines at seven locations along the horizontal meridian of macaque retina using postembedding immunogold labeling with silver intensification. The percentage of GABA+ amacrine profiles was higher in central retina (50-55%) than peripheral retina (30-40%), whereas the percentage of GLY+ amacrine profiles did not vary much with eccentricity (52-57%). GABA and glycine were colocalized in 5-20% of amacrines, depending on the eccentricity, whereas 5-30% of amacrines were not immunoreactive for either neurotransmitter. GABA+ amacrines were slightly larger than GLY+ amacrines or Müller cells. In the ganglion cell layer, 5-20% of neurons were labeled for either GABA or glycine and were identified as displaced amacrines. Of these, 53% were GABA+ only, 11% were GLY+ only, and 37% were double-labeled. A few large, very lightly labeled GABA+ cells were identified as ganglion cells. Other features that varied with eccentricity included the linear density of GABA+ and GLY+ amacrines, and the ratio of amacrines to Müller cells.

Neuronal pathways from the dorsal ocelli of the house cricket, Acheta domesticus.

Each ocellar nerve in the house cricket Acheta domesticus contains giant nerve fibers of 10--15 mum diameter, characterized in Golgi-Cox preparations by a single row of short collaterals which runs along nearly the entire length of a fiber. Numerous long collaterals are given off by thin fibers in the ocellar nerve; medium-size fibers give off relatively few collaterals. The lateral ocellar tracts extend posteriorly through the dorsal protocerebrum, crossing the protocerebral bridge dorsally. The smaller median ocellar tract runs more ventrally through the pars intercerebralis; posterior to the bridge its fibers turn out toward the lateral nerves. Golgi and cobalt preparations reveal branching of giant and medium-size ocellar fibers posterior to the bridge at two levels, forming bilateral regions of ocellar neuropile. No ocellar processes appear to be given off to the corpora pedunculata, central body, nervi corporis cardiaci, antennal lobes, or circumesophageal connectives; it is uncertain whether ocellar collaterals extend into the protocerebral bridge or optic lobes. Cell bodies of giant and medium-sized fibers are located in the pars intercerebralis.

Analysis of sampling strategies for estimating annual average indoor NO2 concentrations in residences with gas ranges.

Range gas consumption in households tends to follow an annual cycle resembling a sinusoid, with peak consumption during the winter. When outdoor NO2 concentrations have a constant or small impact, the resulting indoor NO2 concentrations also tend to resemble an annual sinusoid. Optimal monitoring strategies can be designed to take advantage of this knowledge to obtain a better estimate of the true annual average gas consumption or indoor NO2 concentration. Gas consumption data, together with measured outdoor concentrations, house volumes, sampled emission rates, air exchange rates, and NO2 decay rates, are used to model weekly indoor NO2 concentrations throughout the year. Based on the modeling results, various monitoring strategies are evaluated for their accuracy in estimating the annual mean. Analysis of the results indicates that greater accuracy is attained using samples equally spaced throughout the year. In addition, the expected error for various monitoring strategies and various numbers of equally spaced samples is quantified, and their ability to classify homes into correct concentration categories is assessed.

Causes and consequences of backdrafting of vented gas appliances.

House depressurization occurs when household equipment such as a kitchen or bathroom fan or a fireplace exhausts air from the house and lowers the pressure indoors with respect to the outside. The operation of air handlers for forced-air heating or cooling systems also can have a depressurization effect. This depressurization can hinder the natural draft from vented combustion appliances and lead to backdrafting, which in turn can result in combustion gases spilling into the indoor airspace. Extensive spillage can cause elevated indoor levels of combustion products such as carbon dioxide (CO2) and water vapor, as well as contaminants such as carbon monoxide (CO) and nitrogen dioxide (NO2). The focus of this paper is to review studies on depressurization-induced backdrafting and spillage from gas-fired, drafthood equipped furnaces and domestic hot water heaters. Qualitative and quantitative techniques that were used in depressurization and backdrafting studies conducted in Canada, Europe, and the United States are analyzed. These studies have shown that exhaust fans operated simultaneously with fireplaces depressurize houses by 3 to 8 Pa on average. The CO indoor concentrations due to spillage, as reported in these studies, generally have been lower than 5 ppm. However, such low CO concentrations do not necessarily imply that a potential problem associated with backdrafting does not exist. Other combustion products, such as NO2, rarely have been measured in prior backdrafting studies. It can be concluded from the literature review that causes of house depressurization are well understood. However, more comprehensive research is needed to better understand the frequency, duration, and severity of depressurization-induced spillage in a broad cross section of houses. Efforts in this direction have begun recently in the United States through a workshop to define research issues, pilot studies to develop comprehensive measurement protocols, and consensus standard development activities to prepare standardized methods and protocols.

Longitudinal changes in infant body composition: association with childhood obesity.

BACKGROUND: Rapid weight gain in infancy has been established as a risk factor for the development of later obesity. OBJECTIVE: We aimed to investigate the role of changes in infant body composition (assessed via total body electrical conductivity) on the development of overweight/obesity in mid-childhood. METHODS: Fifty-three term infants were evaluated at birth, three times during infancy and in mid-childhood. Logistic regression was used to determine associations between rates of total weight gain, fat mass gain and lean mass gain during infancy and later overweight/obesity (defined as body mass index [BMI] ≥85th percentile), adjusted for birth weight and parent education. RESULTS: At follow-up (age 9.0 ± 1.8 years), 30% were overweight/obese. More rapid total weight gain from 0 to 4 months was associated with twofold odds (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.05-3.74, P = 0.04) of overweight/obesity in mid-childhood. From 0 to 8 months, more rapid weight gain was associated with nearly fivefold odds (OR 4.76, 95% CI 1.05-21.5, P = 0.04), and more rapid fat mass gain was associated with eightfold odds (OR 8.03, 95% CI 1.11-58.2, P = 0.04) of later overweight/obesity. CONCLUSION: This exploratory study suggests that rapid weight gain, especially fat mass gain, in earlier infancy predisposes to mid-childhood overweight/obesity.

Activity of trabectedin (ET-743, Yondelis) in metastatic uterine leiomyosarcoma.

BACKGROUND: The ongoing search for more effective agents in the treatment of uterine leiomyosarcomas is warranted because of the poor prognosis related to these tumors. CASE: A case of advanced, recurrent and refractory uterine leiomyosarcoma is presented that responded to trabectedin (ET-743) 1.2 mg/m2 intravenously over 24 h every 3 weeks after failing four prior regimens. A durable objective response lasting at least 8 months was documented. CONCLUSION: Trabectedin (ET-743) has activity in uterine leiomyosarcoma and warrants further investigation.

Comparison of immunolocalization patterns for the synaptic vesicle proteins p65 and synapsin I in macaque monkey retina.

The distributions of the two synaptic vesicle proteins p65 [Matthew et al. (1981) J. Cell Biol., 91:257-269] and synapsin I [De Camilli et al. (1983) J. Cell Biol., 96:1337-1354] were compared in macaque monkey retina using pre-embedding immunocytochemistry for both light and electron microscopy. The monoclonal antibody AB-48 against p65 labeled ribbon-containing synaptic terminals of cone, rod, and bipolar cells as well as many conventional synapses of amacrine cells. In contrast, a polyclonal antiserum against synapsin I (SYN I) labeled many amacrine conventional synapses but no photoreceptor or bipolar ribbon synaptic terminals. Horizontal cell pre- and post-synaptic profiles in the outer plexiform layer were not labeled by either antibody. At the light microscopic level, the banding patterns in the inner plexiform layer also differed for the two antibodies, with four bands of AB-48 immunoreactivity in sublayers S1, S2, S4, and S5 but only three bands of SYN I immunoreactivity in S1, S3, and S5. SYN I also labeled varicose fibers in both the inner nuclear layer and the outer plexiform layer that are probably processes of dopaminergic and GABAergic interplexiform cells. Varicose fibers in the ganglion cell layer were labeled by both antibodies. These results provide the first electron microscopic immunocytochemical labeling for AB-48 and SYN I in intact retina and confirm that AB-48 labels both ribbon and conventional synaptic terminals, whereas SYN I labels only conventional synapses.

Group therapy with mothers of incest victims, Part I: Structure, leader attributes, and countertransference.

Reality-based, ego-supportive group therapy is an intervention with mothers of children who were sexually abused by a father, stepfather, or man in the paternal role. Structure and process of a mothers' group that was co-led by the authors and met weekly for 2 years are described in this two part article. In Part I of this article, the structure of the Mothers' Group is described: setting and referral sources, purpose and goals, format, and group composition. Also discussed are the influence of leader attributes on group process, therapeutic interventions related to these attributes, and strategies to handle the potential for counter-transference and minimize its antitherapeutic effects.

Group therapy with mothers of incest victims, Part II: Therapeutic strategies, recurrent themes, interventions, and outcomes.

Part II of this article continues the discussion of group process in a reality-based, ego-supportive therapeutic group for mothers of incest victims that was co-led for 2 years by the authors. Strategies are discussed that fostered development of a therapeutic group. Recurrent themes that emerged in the group are identified. Interventions that provided opportunities for corrective interpersonal experiences are described, as are therapeutic values and beneficial outcomes.

Population activity patterns - St. Louis study.

In the context of exposure monitoring, activity patterns refer to the manner in which individuals' activities are distributed in time, in space, and by environmental mode. The background and design are given for a cross-sectional survey conducted in the St. Louis area during 1978-1979. Activity pattern estimates from the study, based on a combination of usual frequency and diary methods, are presented and their limitations are discussed. Methods for and the types of estimates from national studies employing time-use diaries are presented. Considerations for activity pattern recording during future monitoring studies are provided.