Activation of neural stem cells from quiescence drives reactive hippocampal neurogenesis after alcohol dependence

Neural stem cell-driven adult neurogenesis contributes to the integrity of the hippocampus. Excessive alcohol consumption in alcoholism results in hippocampal degeneration that may recover with abstinence. Reactive, increased adult neurogenesis during abstinence following alcohol dependence may contribute to recovery, but the mechanism driving reactive neurogenesis is not known. Therefore, adult, male rats were exposed to alcohol for four days and various markers were used to examine cell cycle dynamics, the percentage and number of neural progenitor cell subtypes, and the percentage of quiescent versus activated progenitors. Using a screen for cell cycle perturbation, we showed that the cell cycle is not likely altered at 7 days in abstinence. As the vast majority of Bromodeoxyuridine-positive (+) cells were co-labeled with progenitor cell marker, Sox2, we then developed a quadruple fluorescent labeling scheme to examine Type-1, -2a, -2b and -3 progenitor cells simultaneously. Prior alcohol dependence indiscriminately increased all subtypes at 7 days, the peak of the reactive proliferation. An evaluation of the time course of reactive cell proliferation revealed that cells begin proliferating at 5 days post alcohol, where only actively dividing Type 2 progenitors were increased by alcohol. Furthermore, prior alcohol increased the percentage of actively dividing Sox2+ progenitors, which supported that reactive neurogenesis is likely due to the activation of progenitors out of quiescence. These observations were associated with granule cell number returning to normal at 28 days. Therefore, activating stem and progenitor cells out of quiescence may be the mechanism underlying hippocampal recovery in abstinence following alcohol dependence.

Type 2 Neural Progenitor Cell Activation Drives Reactive Neurogenesis after Binge-Like Alcohol Exposure in Adolescent Male Rats

Excessive alcohol consumption during adolescence remains a significant health concern as alcohol drinking during adolescence increases the likelihood of an alcohol use disorder in adulthood by fourfold. Binge drinking in adolescence is a particular problem as binge-pattern consumption is the biggest predictor of neurodegeneration from alcohol and adolescents are particularly susceptible to the damaging effects of alcohol. The adolescent hippocampus, in particular, is highly susceptible to alcohol-induced structural and functional effects, including volume and neuron loss. However, hippocampal structure and function may recover with abstinence and, like in adults, a reactive burst in hippocampal neurogenesis in abstinence may contribute to that recovery. As the mechanism of this reactive neurogenesis is not known, the current study investigated potential mechanisms of reactive neurogenesis in binge alcohol exposure in adolescent, male rats. In a screen for cell cycle perturbation, a dramatic increase in the number of cells in all phases of the cycle was observed at 7 days following binge ethanol exposure as compared to controls. However, the proportion of cells in each phase was not different between ethanol-exposed rats and controls, indicating that cell cycle dynamics are not responsible for the reactive burst in neurogenesis. Instead, the marked increase in hippocampal proliferation was shown to be due to a twofold increase in proliferating progenitor cells, specifically an increase in cells colabeled with the progenitor cell marker Sox2 and S-phase (proliferation) marker, BrdU, in ethanol-exposed rats. To further characterize the individual subtypes of neural progenitor cells (NPCs) affected by adolescent binge ethanol exposure, a fluorescent quadruple labeling technique was utilized to differentiate type 1, 2a, 2b, and 3 progenitor cells simultaneously. At one week into abstinence, animals in the ethanol exposure groups had an increase in proliferating type 2 (intermediate progenitors) and type 3 (neuroblast) progenitors but not type 1 neural stem cells. These results together suggest that activation of type 2 NPCs out of quiescence is likely the primary mechanism for reactive hippocampal neurogenesis following adolescent alcohol exposure.

Alcohol and adult hippocampal neurogenesis: promiscuous drug, wanton effects

Adult neurogenesis is now widely accepted as an important contributor to hippocampal integrity and function but also dysfunction when adult neurogenesis is affected in neuropsychiatric diseases such as alcohol use disorders. Excessive alcohol consumption, the defining characteristic of alcohol use disorders, results in a variety of cognitive and behavioral impairments related wholly or in part to hippocampal structure and function. Recent preclinical work has shown that adult neurogenesis may be one route by which alcohol produces hippocampal neuropathology. Alcohol is a pharmacologically promiscuous drug capable of interfering with adult neurogenesis through multiple mechanisms. This review will discuss the primary mechanisms underlying alcohol-induced changes in adult hippocampal neurogenesis including alcohol's effects on neurotransmitters, CREB and its downstream effectors, and the neurogenic niche.

Determining the threshold for alcohol-induced brain damage: new evidence with gliosis markers

BACKGROUND

Chronic intake of ethanol (EtOH) has been linked to serious health consequences such as cardiac and liver problems, cognitive impairments, and brain damage. Alcohol's detrimental effects depend upon the dose, duration, and pattern of exposure with binge drinking as one of the most common, but most damaging, patterns of intake. Little is known about the threshold of the damaging effects of alcohol. Therefore, these experiments sought to determine a threshold for brain damage using various markers of neurodegeneration.

METHODS

Adult male Sprague-Dawley rats were administered nutritionally complete liquid diet containing either EtOH (25% w/v) or isocaloric dextrose every 8 hours for either 1 (mean dose, 13.4 ± 0.3 g/kg/d; mean blood EtOH concentration (BEC), 336.2 ± 18.8 mg/dl) or 2 days (mean dose, 10.9 ± 0.3 g/kg/d; mean BEC, 369.8 ± 18.1 mg/dl). On the basis of a known time course of various neurodegeneration-associated events, rats were perfused transcardially immediately following, 2 days after, or 7 days post EtOH exposure. To label actively dividing cells, some animals were injected with BromodeoxyUridine (BrdU) 2 hours prior to perfusion. Tissue was then analyzed for the presence of BrdU (cell proliferation), FluoroJade B (degenerative neurons), and vimentin (reactive astrogliosis) immunoreactivity.

RESULTS

One or 2 days of EtOH exposure failed to alter cell proliferation at any of the time points analyzed. However, significant 2- to 9-fold increases in neuronal degeneration in limbic cortex and clear evidence of reactive gliosis as indicated by a 2- to 8-fold upregulation in vimentin immunoreactivity in the hippocampus were observed following as little as 1 day of binge EtOH exposure.

CONCLUSIONS

These results indicate that as little as 1 day (24 hours) of high BEC, binge-like EtOH exposure is enough to elicit signs of alcohol-induced brain damage in adult rats. Further, reactive gliosis may be a more sensitive marker of alcohol-induced damage in the hippocampus.

Neuropeptide Y signaling modulates the expression of ethanol-induced behavioral sensitization in mice

Neuropeptide Y (NPY) and protein kinase A (PKA) have been implicated in neurobiological responses to ethanol. We have previously reported that mutant mice lacking normal production of the RIIβ subunit of PKA (RIIβ-/- mice) show enhanced sensitivity to the locomotor stimulant effects of ethanol and increased behavioral sensitization relative to littermate wild-type RIIβ+/+ mice. We now report that RIIβ-/- mice also show increased NPY immunoreactivity in the nucleus accumbens (NAc) core and the ventral striatum relative to RIIβ+/+ mice. These observations suggest that elevated NPY signaling in the NAc and/or striatum may contribute to the increased sensitivity to ethanol-induced behavioral sensitization that is a characteristic of RIIβ-/- mice. Consistently, NPY-/- mice failed to display ethanol-induced behavioral sensitization that was evident in littermate NPY+/+ mice. To examine more directly the role of NPY in the locomotor stimulant effects of ethanol, we infused a recombinant adeno-associated virus (rAAV) into the region of the NAc core of DBA/2J mice. The rAAV-fibronectin (FIB)-NPY(13-36) vector expresses and constitutively secretes the NPY fragment NPY(13-36) (a selective Y(2) receptor agonist) from infected cells in vivo. Mice treated with the rAAV-FIB-NPY(13-36) vector exhibited reduced expression of ethanol-induced behavioral sensitization compared with mice treated with a control vector. Taken together, the current data provide the first evidence that NPY signaling in the NAc core and the Y(2) receptor modulate ethanol-induced behavioral sensitization.

Adolescent binge alcohol exposure alters hippocampal progenitor cell proliferation in rats: effects on cell cycle kinetics

Binge alcohol exposure in adolescent rats potently inhibits adult hippocampal neurogenesis by altering neural progenitor cell (NPC) proliferation and survival; however, it is not clear whether alcohol results in an increase or decrease in net proliferation. Thus, the effects of alcohol on hippocampal NPC cell cycle phase distribution and kinetics were assessed in an adolescent rat model of an alcohol use disorder. Cell cycle distribution was measured using a combination of markers (Ki-67, bromodeoxyuridine incorporation, and phosphohistone H3) to determine the proportion of NPCs within G1, S, and G2/M phases of the cell cycle. Cell cycle kinetics were calculated using a cumulative bromodeoxyuridine injection protocol to determine the effect of alcohol on cell cycle length and S-phase duration. Binge alcohol exposure reduced the proportion of NPCs in S-phase, but had no effect on G1 or G2/M phases, indicating that alcohol specifically targets S-phase of the cell cycle. Cell cycle kinetics studies revealed that alcohol reduced NPC cell cycle duration by 36% and shortened S-phase by 62%, suggesting that binge alcohol exposure accelerates progression through the cell cycle. This effect would be expected to increase NPC proliferation, which was supported by a slight, but significant increase in the number of Sox-2+ NPCs residing in the hippocampal subgranular zone following binge alcohol exposure. These studies suggest the mechanism of alcohol inhibition of neurogenesis and also reveal the earliest evidence of the compensatory neurogenesis reaction that has been observed a week after binge alcohol exposure.

Comparison of basal neuropeptide Y and corticotropin releasing factor levels between the high ethanol drinking C57BL/6J and low ethanol drinking DBA/2J inbred mouse strains

BACKGROUND

Recent genetic and pharmacological evidence indicates that low neuropeptide Y (NPY) levels in brain regions involved with neurobiological responses to ethanol promote increased ethanol consumption. Because of their opposing actions, it has been suggested that NPY and corticotropin releasing factor (CRF) exert a reciprocal regulation on drug self-administration. It has been widely reported that inbred C57BL/6 mice consume significantly higher amounts of ethanol than do DBA/2 mice. Therefore, we used immunohistochemical techniques to determine if basal NPY and/or CRF levels differed in predicted directions between C57BL/6J and DBA/2J mice.

METHODS

Ethanol-naive C57BL/6J and DBA/2J mice were deeply anesthetized with sodium pentobarbital (100 mg/kg) and perfused transcardially with 0.1 mM of phosphate-buffered saline followed by 4% paraformaldehyde in buffered saline. Brains were collected and postfixed for 4 hr at 4 degrees C and then were cut into 35-microm sections. Tissues containing the nucleus accumbens (NAc), hypothalamus, and amygdala were processed for NPY or CRF immunoreactivity using immunofluorescent or DAB techniques. Immunoreactivity was quantified from digital images using Image J software.

RESULTS

The C57BL/6J mice showed reduced NPY expression in the NAc shell, the basolateral amygdala, and the central nucleus of the amygdala when compared with DBA/2J mice. However, these strains did not differ in CRF expression in any of the brain regions analyzed.

CONCLUSIONS

These data suggest that low NPY levels in the amygdala and/or the shell of the NAc, which are not compensated for by similar changes in CRF levels, may contribute to the high ethanol consumption characteristic of C57BL/6J mice.

Peripheral and central administration of a selective neuropeptide Y Y1 receptor antagonist suppresses ethanol intake by C57BL/6J mice

BACKGROUND

Neuropeptide Y (NPY) is a 36-amino acid neuromodulator that is expressed throughout the central nervous system. Recent genetic and pharmacological evidence suggests that the NPY Y1 receptor modulates ethanol intake. To further characterize the role of the Y1 receptor, we examined voluntary ethanol consumption by mice after administration of [(-)-2-[1-(3-chloro-5-isopropyloxycarbonylaminophenyl)ethylamino]-6-[2-(5-ethyl-4-methyl-1,3-tiazol-2-yl)ethyl]-4-morpholinopyridine] (compound A), a novel and selective Y1 receptor antagonist (Y1RA) that acts centrally on brain receptors when administered peripherally.

METHODS

C57BL/6J mice were habituated to drinking a 10% (v/v) ethanol solution by using a two-bottle-choice procedure and were then given an intraperitoneal (ip) injection (5 ml/kg) of the Y1RA (0, 25, 50, or 75 mg/kg). In a second study, mice were given intracerebroventricular infusion of the Y1RA (0, 30, or 100 microg). Finally, we determined whether the Y1RA alters open-field locomotor activity, ethanol-induced sedation (3.8 g/kg, ip), or blood ethanol levels.

RESULTS

Relative to control treatment, ip injection (50 and 75 mg/kg) and intracerebroventricular infusion (100 microg) of the Y1RA significantly reduced ethanol consumption and food intake without altering water drinking. However, the Y1RA did not alter open-field locomotor activity, ethanol-induced sedation, or blood ethanol levels.

CONCLUSIONS

These data indicate that acute blockade of the NPY Y1 receptor with a systemically bioavailable NPY Y1RA reduces voluntary ethanol consumption by C57BL/6J mice. These results are consistent with observations that hypothalamic infusion of NPY increases ethanol drinking by rats.

A role for neuropeptide Y in neurobiological responses to ethanol and drugs of abuse

In recent years, evidence has emerged suggesting that neuropeptide Y (NPY) is involved with neurobiological responses to ethanol and other drugs of abuse. Here, we provide an overview of physiological, pharmacological, and genetic research showing that: (A) administration of ethanol, as well as ethanol withdrawal, alter central NPY expression, (B) NPY modulates ethanol consumption under certain conditions, and (C) NPY signaling modulates the sedative effects of several drugs, including ethanol, sodium pentobarbital, and ketamine. Evidence suggesting possible mechanism(s) by which NPY signaling modulates ethanol consumption are considered. It is suggested that NPY may influence ethanol consumption by regulating basal levels of anxiety, by modulating the sedative effects of ethanol, and/or by modulating ethanol's rewarding properties.

Trafficking and surface expression of the glutamate receptor subunit, KA2

Kainate receptors are a class of ionotropic glutamate receptors that are widely expressed in the mammalian brain, yet little is known about their physiological role or the mechanisms by which they are regulated. Kainate receptors are composed of multiple subunits (GluR5-7; KA1-2), which can combine to form homomeric or heteromeric channels. While the kainate receptor subunit KA2 can combine with GluR5-7 to form heteromeric channels, it does not form functional homomeric channels when expressed alone. In an attempt to identify the molecular mechanisms for this, we have characterized the trafficking and surface expression of KA2. We find that KA2 alone does not traffic to the plasma membrane and is retained in the endoplasmic reticulum (ER). In contrast, co-expression with GluR6 disrupts ER-retention of KA2 and allows plasma membrane expression. Using a chimeric reporter protein we have identified an ER-retention motif within the KA2 cytosolic domain. Recent studies have identified a consensus ER-retention motif (RRR) that is contained within both the NMDA receptor NR1 subunit and K(+) channels. While KA2 contains a similar stretch of amino acids within its C-terminus (RRRRR), unlike the NR1 motif, disruption of this motif with alternating glutamic acid residues does not disrupt ER-retention of KA2, suggesting a unique mechanism regulating KA2 surface expression.

Homophobia within schools: challenging the culturally sanctioned dismissal of gay students and colleagues

In this paper we chronicle the prevalence of and cultural prescription for homophobia in the United States. The endemic nature of homophobia as it has been studied by behavioral scientists is reviewed. We then suggest that as social institutions reflecting cultural values, schools, colleges, and universities sanction an environment that neglects the value of gay students, staff, and faculty. Institutional homophobia dismisses the legitimacy of these individuals, thereby minimizing their contributions to learning. Addressed specifically are suggestions for training individuals who work with students to recognize, address, and challenge homophobia. We conclude that while the weight of American culture sanctions homophobia, training educators and personnel about the nuances of institutional homophobia may provide a fairer environment for gay students and colleagues. An appendix of resources describing effective programs for educational and training use is provided.

High dose toremifene for estrogen and progesterone receptor negative metastatic breast cancer: a phase II trial of the Cancer and Leukemia Group B (CALGB)

In pre-clinical and limited clinical studies, high doses ( > or = 200 mg/day) of the triphenylethylene derivative toremifene showed activity in estrogen receptor (ER) negative and ER-unknown metastatic breast cancer after progression on tamoxifen, and a mechanism of action independent of hormone receptor binding was speculated. The CALGB conducted a Phase II trial (CALGB 8945) to test the efficacy of high dose toremifene in a population of patients who had hormone receptor-negative, metastatic breast cancer with limited prior chemotherapy exposure, good performance status, and measurable disease. Twenty eligible patients received toremifene at a dose of 400 mg/day orally for 8 weeks. Toxicity was minimal. Nausea was reported by 20% of the patients, lightheadedness by 20%, weight loss by 20%, and hot flashes by 15%. There was no grade 3-4 toxicity. No objective responses were observed, and 5 of 6 patients with stable disease at 8 weeks developed progressive disease at 11 to 33 weeks. High dose toremifene (400 mg/day) is well-tolerated but imparts no detectable activity in hormone receptor-negative, metastatic breast cancer.

Silver enhancement of gold antibody probes in pre-embedding electron microscopic immunocytochemistry

In pre-embedding EM immunocytochemistry with gold probes, the gold must be small enough to penetrate through cell membranes treated with mild detergents. Antibodies labeled with small gold probes (1-1.4 nm) are too small to be resolved in thin sections but can be seen if they are silver-enhanced after the gold has bound to the antigens in the cells. We investigated several aspects of gum arabic-silver lactate-hydroquinone enhancement solution (Danscher solution) by examining gold-conjugated antibodies embedded in agar, sectioned on a vibrotome, and enhanced with different solutions. The rate of silver enhancement was optimized in 50% gum arabic and 200 mM HEPES buffer, pH 5.8. We also examined chemicals used as developers and found that N-propyl gallate (NPG) gave a more uniform development than the routinely used hydroquinone (HQ). The diameter of the silver-enhanced particles after incubation in osmium tetratoxide (OSO4) decreased somewhat with longer incubation time and higher percentages, but the density (number per unit area) of silver-enhanced particles was little changed. The loss of silver-enhanced particle diameter was reduced by lowering the concentration of OSO4 to 0.1%. Comparison of commercial small gold probes showed that NPG enhancement of Nanogold gave more uniform particle size and a better correlation between enhancement time and particle density. When this procedure was applied to cell cultures with monoclonal antibodies, the silver-enhanced particles were similar to those in the agar sections. When free-floating tissue sections were used, longer silver enhancement times were needed to obtain similarly sized particles. This new NPG-silver-enhancement procedure offers a reliable and easy method to localize proteins in cultured cells and tissue sections by pre-embedding electron microscopic immunocytochemistry.

GAP-43 distribution is correlated with development of growth cones and presynaptic terminals

GAP-43 (F1, B-50, pp46) has been associated with neuronal development and regeneration, but precise localization within neurons is not known. Pre-embedding electron microscopic immunocytochemistry using silver-enhanced 1 nm gold particles was used to localize GAP-43 label in cell cultures of cerebellar neurons. In the plasma membranes of early cultures, high levels of GAP-43 were seen in all parts of the neuron. In older cultures, consistent with previous reports, the first loss of GAP-43 label was seen in the soma and then the axon. Growth cones had high levels of GAP-43 label on the plasma membrane, with increased distribution over unattached relative to attached filopodia. The amount of GAP-43 seen over the plasma membrane of forming presynaptic terminals is lower than over growth cones, indicating a possible correlation between the presence of GAP-43 and the stage of presynaptic terminal development. Intracellular GAP-43 in axons and growth cones was highest in membranes of smooth cisternae. The levels of GAP-43 in smooth cisternae in axons fell by seven days in culture while the levels of GAP-43 in smooth cisternae of growth cones fell at 14 days. When mini-explant cerebellar cultures were examined with light microscopic immunocytochemistry, GAP-43 label of plasma membrane was highest at the periphery of the radial axonal outgrowth, suggesting that addition of GAP-43 to the plasma membrane can occur in the distal axon or at the growth cone.

Redistribution of GAP-43 during growth cone development in vitro; immunocytochemical studies

The growth-associated protein GAP-43 (B-50, F1, pp46), has been found in elongating axons during development and regeneration, and has also been associated with synaptic plasticity in mature neurons. We have examined the loss of GAP-43 labelling from cerebellar granule cells with immunocytochemical localization of a polyclonal antibody to GAP-43. One day after plating, the plasma membrane of cell bodies, neurites and growth cones were all labelled with anti-GAP-43. By 10 days, most of the cell body labelling was lost, and by 20 days the neuritic and growth cone labelling was greatly reduced. Beginning at six days, anti-GAP-43 labelling of growth cones, which was initially uniform, became clustered. When growth cones were double-labelled with antibodies to GAP-43 and the synaptic vesicle protein, p65, inverse changes in the distribution of label was observed. While growth cone labelling with anti-p65 increased from three to 20 days in culture, GAP-43 label began to be lost from some growth cones by six days and showed continuing decline through 20 days. For individual growth cones, the loss of GAP-43 appeared to parallel the accumulation of p65, and first growth cones to lose GAP-43 appeared to be the first to accumulate p65 label. When cultures were grown on a substrate of basement membrane material, the time frames of neuritic outgrowth, loss of GAP-43 labelling, and increase in p65 labelling were all accelerated. At five days, labelling for GAP-43 was weak and labelling for p65 was strong, in a pattern comparable to that seen in older cultures on a polylysine substrate. These results suggest several conclusions concerning the expression and loss of GAP-43 in cultured cerebellar granule neurons. First, GAP-43 label is initially distributed in all parts of these cells. With increasing time in culture the label is first lost from cell bodies and later from neurites and growth cones. Second, the loss of GAP-43 label from growth cones is correlated with the appearance of the synaptic vesicle protein p65. Finally, in vitro developmental changes in the loss of GAP-43 can be altered by changing the growth substrate.

Appendiceal goblet cell carcinoids: a clinicopathological and immunohistochemical study

Goblet cell carcinoids are uncommon but distinctive tumours of the appendix. We have reviewed 11 cases diagnosed within the period 1976-1990. The mean age at presentation was 58 years (range 24-76), with a female:male ratio of 8:3. At presentation, in seven patients tumour was confined to the appendix or mesoappendix (mean age 51) and in four there was extension beyond the appendix (mean age 69). Of the seven patients with localized tumour, six are alive and without clinical disease after a mean follow-up period of 32 months and one died with recurrent tumour after 10 years. Of the four with more extensive disease, two died during follow-up (at 23 months with probable liver metastases and at 16 months with intestinal obstruction) and two are alive, one with disease and one clinically disease-free. Immunohistochemistry showed that all of the tumours stained positively for either neuron-specific enolase, chromogranin A or protein gene product 9.5. No tumour stained with antiserum to substance P and none showed glucagon-like immunoreactivity, but four cases stained positively for pancreatic polypeptide, an unusual feature in midgut carcinoids.

Phase II study of oral idarubicin in favorable histology non-Hodgkin's lymphoma

Idarubicin, a new analogue of daunorubicin, was administered p.o. for 3 consecutive days every 3 weeks at a dose of 45 mg/m2 in 46 patients (45 eligible and evaluable) with previously treated, favorable histology, non-Hodgkin's lymphoma. Median clinical characteristics included an age of 66 years, a performance status of 1, and one prior chemotherapeutic regimen. Forty-one patients were relapsing from prior therapy, and 37 had stage IV disease. Patients with prior anthracycline therapy were excluded. Responses were observed in 58% of patients (10 complete and 16 partial), with a median duration of 6+ months (2-41+ months). Idarubicin was well tolerated. Nonhematological toxicities (nausea/vomiting, mucositis/diarrhea, alopecia, and anorexia) were observed in less than or equal to 50% of patients. Median hematological values during the first cycle include a WBC of 4100/mm3 and a platelet count of 147,000/mm3. With dose escalation, hematological toxicity was the dose-limiting toxicity. Symptomatic cardiac toxicity was not observed. Median values for the resting left ventricular ejection fraction during the course of therapy were 0.65 (initial) and 0.63 (final). Idarubicin in oral form is an active drug in previously treated patients with favorable histology non-Hodgkin's lymphoma.

A neutral pH silver development method for the visualization of 1-nanometer gold particles in pre-embedding electron microscopic immunocytochemistry

The availability of 1-nm gold particles permits the use of a particulate label with standard pre-embedding electron microscopic immunocytochemical techniques. We have employed these particles to localize a synaptic vesicle protein, p65, and a growth-associated protein, GAP-43, in neuron cell cultures. To be detected by standard transmission electron microscopy, these ultra-small gold particles must be enlarged. We have applied a commercially available silver development kit (IntenseM), the method of Danscher, and a neutral pH development procedure which we developed to effect this enlargement. Although IntenseM permits development with good preservation of morphology, it is limited by lack of reproducibility and by variability of final particle size. The method of Danscher provides well-controlled and reproducible enlargement, but is limited with respect to preservation of ultrastructural details. The neutral pH development procedure reproducibly enlarges gold particles with superior preservation of morphology. The use of this development procedure in conjunction with 1-nm gold probes should permit precise ultrastructural localization of a variety of intracellular antigens.

Phase II trial of etoposide and cisplatin for refractory small cell lung cancer: a Cancer and Leukemia Group B Study

A phase II trial of etoposide and cisplatin for patients with previously treated small cell lung cancer was carried out by CALGB from June 1983 to May 1984. Thirty-five evaluable patients who had failed one prior chemotherapy regimen were treated with etoposide 80 mg/m2 and cisplatin 20 mg/m2 days 1-5 every 3 weeks. Objective responses were seen in 7 patients (20%) with 1 complete response and 6 partial responses. The median duration of response was 5.1 months. Fifteen patients (43%) had stable disease. Overall survival was 49% at 6 months and 14% at 1 year. The median survival was 6 months. Toxicity was mainly hematologic with severe and life-threatening leukopenia and thrombocytopenia seen in 71% and 66% of patients, respectively. Two treatment-related deaths caused by infection were seen. This cooperative group study fails to confirm the high response rates previously reported in institutional pilot studies.

Highly basic 30- and 32-kilodalton proteins associated with synapse formation on polylysine-coated beads in enriched neuronal cell cultures

Neuronal proteins involved in axonal outgrowth and synapse formation were examined in an enriched neuronal cell culture system of the cerebellum. In rat cerebellar cell cultures, 98.9% of the cells are neurons and the remaining 1.1% of the cells are flat nonneuronal cells. These enriched neuronal cultures, examined with two-dimensional gel electrophoresis, showed protein patterns similar to those of neonatal cerebellum, but very different patterns from glial enriched cultures. High levels of a neuronal membrane acidic 29-kilodalton (kD) protein were found. It has been shown previously that neuronal cultures incubated with polylysine-coated beads will develop numerous presynaptic elements on the bead surface. We report here that isolation of the beads from enriched neuronal cell cultures incubated with [35S]methionine showed, with two-dimensional nonequilibrium pH gradient gel electrophoresis (2D-NEPHGE), levels of a basic 32-kD protein (pI 8) note detected in cultures alone, and increased levels of a 30-kD protein (pI 10). When culture medium was examined with 2D-NEPHGE, three acidic proteins were identified that were secreted by the cultured neurons. In summary, a neuronal enriched cell culture system was used with isolated polylysine-coated beads to identify basic 30-kD and 32-kD proteins that may be involved in synapse formation.

Diffuse well-differentiated lymphocytic lymphoma: chemotherapy with BCNU, cyclophosphamide, vincristine, melphalan and prednisone

Twenty patients with stage III and IV diffuse well-differentiated lymphocytic lymphoma were treated with combination chemotherapy consisting of BCNU, cyclophosphamide, vincristine, melphalan and prednisone (M-2). Treatment was given every 5 weeks for 11 cycles in responding patients. The median age of the patients was 62 years (range 45-76). There were 12 complete remissions and 6 partial remissions for an overall response rate of 90%. The median duration of remission was 24 months (range 12-79 months) and was identical for complete responders and partial responders. All but 2 responding patients have been subsequently retreated for relapse. The median survival was 84 months (range 1-108 months). Myelosuppression was mild. Nausea/vomiting, neuropathy, alopecia and gastrointestinal symptoms from prednisone were seen in the minority of patients. One patient expired from sepsis/neutropenia during the first cycle of therapy. The M-2 protocol produces effective remissions in diffuse well-differentiated lymphocytic lymphoma. The relapse and survival pattern are similar to the results achieved with other chemotherapy regimens in low-grade lymphoma.

Incendiary characteristics of a new laser-resistant endotracheal tube

Endotracheal tube fires are the most frequent complication of laser surgery of the larynx. We investigated the incendiary characteristics of a new laser-resistant endotracheal tube, compared to polyvinyl chloride (PVC) and red rubber (RR) tubes, with different gas mixtures. A CO2 laser was focused on each tube and the probability of fire was assessed with oxygen fractions (FiO2) of 30%, 40%, 50%, 70%, and 100%, the balance being N2 or N2O. The laser-resistant tube could not be penetrated by a single laser pulse, regardless of laser energy or gas composition. PVC and RR tubes were readily ignited, the probability of ignition being related to oxygen concentration and laser energy. Nitrous oxide readily supported combustion. We suggest that laser surgery of the larynx can be most safely performed with a laser-resistant endotracheal tube and with gas mixtures containing the minimal safe O2 concentration (without nitrous oxide).

Development and elimination of presynaptic elements on polylysine-coated beads implanted in neonatal rat cerebellum

Polylysine-coated sepharose beads were implanted in the cerebellum of neonatal rats and examined at 3 hr, 3 days, 7 days, 14 days, and 21 days after surgery. Previous studies at 5 or 8 days after implantation showed that axons formed neuronal swellings that appeared to be presynaptic elements, with the bead surface in the position of a postsynaptic element. Results reported here show that no beads at 3 hr had presynaptic elements, whereas the number of beads with presynaptic elements increased to high levels at 3 and 7 days but dropped to low values at 14 and 21 days after implantation. Presynaptic elements were seen on beads regardless of their distance from cerebellar tissue except at 3 hr, when no axons were seen in the implant, indicating that axons first grew into the implant and then formed presynaptic elements. The morphological measurements of presynaptic elements on beads at 3 to 7 days after implantation showed increases in area and number of synaptic vesicles, which then decreased at 14 and 21 days after implantation. These results show that axons can grow into implants of polylysine-coated beads and form presynaptic elements that do not survive with increased time after implantation. The survival of presynaptic elements on beads can be used as a model for investigations into regeneration of axons and presynaptic elements in the injured brain.

Phase II study of aclarubicin in patients with lymphoma

Aclarubicin, a new anthracycline antibiotic with less cardiotoxicity relative to doxorubicin, was utilized in 33 patients with advanced lymphoma at a dose of 100 mg/m2 iv every 3 weeks. Five patients developed partial response (2, 2, 2, 4, and 8+ months). None of the patients who had received prior anthracycline responded to aclarubicin. The dose-limiting toxic effect was hematologic. One of ten patients having serial measurements of cardiac function had a significant reduction in left ventricular function, but cardiac symptoms did not occur.

Combination chemotherapy for multiple myeloma with BCNU, cyclophosphamide, vincristine, melphalan, and prednisone (M-2 protocol)

54 consecutively referred, previously untreated patients with stage II and III multiple myeloma have been treated with the M-2 protocol. 50% of patients had a performance status of less than 50%. 13% were stage II and 87% stage III. In 50 of 54 patients (90%), and objective response according to the Myeloma Task Force was achieved; 10% of the responses have been complete (9+, 15+, 17+, 18+ and 66+ months). Remissions now range from 1 to 86+ months. The actuarial median survival determined from the initiation of therapy will exceed 4 years. Toxicity was acceptable with mild myelosuppression. These results confirm the efficacy of the M-2 protocol in multiple myeloma with regards to response rate and survival.

Phase II study of aziridinylbenzoquinone in refractory lymphoma

Aziridinylbenzoquinone (AZQ), an alkylating agent with lipophilic properties allowing CNS penetration, has been studied in a phase II trial in patients with refractory lymphoma. Thirty-five patients (ages, 24-84 years) have been treated using AZQ at a dose of 30 mg/m2 every 3 weeks. Nine patients (26%) have responded (complete responses for 14+, 12+, 4, 3, and 3 months; partial responses for 7, 2, 2, and 2 months). Seven of the nine responses were seen in patients with diffuse histologies, particularly diffuse histiocytic lymphoma. One of two patients with CNS lymphoma responded completely. Complete remissions were observed only in patients receiving not more than one prior chemotherapeutic protocol. The drug was well-tolerated. Neutropenia was brief and acceptable. However, cumulative thrombocytopenia occurred even in patients without prior nitrosourea therapy and necessitated significant dosage reductions with subsequent cycles. AZQ appears active in lymphomas, especially in diffuse histiocytic lymphoma. The possibility of using AZQ in CNS lymphoma should be further explored.

Stable E rosette-forming lymphocytes in the peripheral blood in non-Hodgkin's lymphoma

The peripheral blood of 49 patients with non-Hodgkin's lymphoma and the same number of normal controls was examined for the presence of lymphocytes forming rosettes with sheep erythrocytes at 37 degrees C (stable E rosettes). Nineteen lymphoma patients but only five normal controls showed increased absolute levels. (P less than 0.01). There was no correlation between the occurrence of increased Stable E Rosette levels and the histological type of lymphoma but there appears to be a positive relationship with the presence of clinical stage III-IV disease at presentation (P = 0.011). It is suggested that stable E rosettes represent an immunological response to residual lymphoma in our patients. A longitudinal study in one patient is reported in detail to demonstrate the occurrence of fluctuations in stable E rosette levels coinciding with clinical changes.

Size Distributions and Mineralogy of Ash Particles in the Stratosphere from Eruptions of Mount St. Helens

Samples from the stratosphere obtained by U-2 aircraft after the first three major eruptions of Mount St. Helens contained large globules of liquid acid and ash. Because of their large size, these globules had disappeared from the lower stratosphere by late June 1980, leaving behind only smaller acid droplets. Particle-size distributions and mineralogy of the stratospheric ash grains demonstrate in-homogeneity in the eruption clouds.

Combination chemotherapy for non-Hodgkin lymphomas: a ten year follow-up study

In 1968 the Cancer and Acute Leukemia Group B (CALGB) demonstrated optimal control of disseminated non-Hodgkin lymphomas (NHL) with vincristine-prednisone induction followed by cyclophosphamide maintenance. A study was then begun to determine whether four drugs in combination or sequence could achieve greater control. NHL patients at each participating CALGB institution were randomly assigned to one of three regimens:I) Cyclic vincristine-streptonigrin alternating every 2 weeks with cyclophosphamide-prednisone up to 155 days; II) Sequential treatment with the same 4 drugs taken singly up to 182 days; and III) Vincristine-prednisone induction for 6 weeks followed by cyclophosphamide maintenance. Results are now reported after a 10 year follow-up period. The 203 evaluable patients are those on whom Rappaport histopathologic classification was available. Frequency of complete-response did not differ significantly among the three regimens: I) 38%; II) 30%; and III) 45%. Remission durations were significantly longer among patients receiving maintenance therapy. After ten years, two patients from Regimen I, one from Regimen II, and five from Regimen III remain alive and well. It was concluded that neither of the four-drug regimens conferred a significant advantage in terms of response rate or survival time over the standard treatment.

Perceptions of cancer care by professionals and nonprofessionals

Critical incident descriptions were obtained by questionnaire from 472 practicing physicians, 59 medical students, 31 house officers, 50 clinical faculty, and 43 allied health professionals. Descriptions were obtained by interview from 660 cancer patients and their families, and from 250 noncancer patients. The resulting 4,877 vignettes were analyzed and dissected to yield 13,009 separate, identifiable critical behaviors, i.e., behaviors deemed critical to the delivery of optimal care. After elimination of duplication and those items not specifically relevant to cancer, there remained 339 distinct attributes of an effective cancer care system. The results confirmed that the nonprofessionals are most concerned with items in the affective domain while the professionals are most concerned with items of a technological nature. However, there was a good deal of overlap in these areas of concern, and it appears from it that "needs" as expressed by professionals and "wants" as expressed by nonprofessionals often represent the same things couched in different terms. This study also yielded a list of desirable competencies of value as educational objectives for programs of profes sional education in cancer care.

Acute renal failure after cis-dichlorodiammineplatinum(II) and gentamicin-cephalothin therapies

Combined gentamicin-cephalothin therapy in four patients after treatment with cis-dichlorodiammineplatinum(II) (CPDD) for advanced solid tumors was complicated by severe acute renal failure. The total dose of gentamicin varied from 240 to 945 mg and that of cephalothin varied from 28 to 48 g. Low-dose (0.5 mg/kg x 8) CPDD was given to one patient, high-dose (3 mg/kg) CPDD was given to two patients, and very high-dose (5 mg/kg) CPDD was given to one patient. The high and very high doses of CPDD were given with concomitant mannitol diuresis. CPDD therapy was complicated by mild transient azotemia in three patients and by severe acute renal failure in one. In the latter, the azotemia began to improve on Day 7 after CPDD treatment. Following gentamicin-cephalothin therapy, all patients developed severe acute renal failure which persisted until death. At autopsy, all patients had extensive renal tubular necrosis at various stages. These findings indicate that gentamicin-cephalothin therapy after treatment with CPDD can be severely nephrotoxic, and that this antibiotic combination should be given with great caution, if at all, to patients receiving CPDD treatment for malignancy.

The renal pathology in clinical trials of cis-platinum (II) diamminedichloride

The pathologic changes induced by Cis-platinum (II) diamminedichloride (CPDD) therapy in the kidneys are described in 12 patients with solid tumors and malignant lymphomas. According to dosage of CPDD the patients were divided into two groups: 1) low-dose group--.0.5-2 mg/kg daily, for 1 to 6 days; and 2) high-dose group--single injection of 3 or more mg/kg with concommitant mannitol-induced diuresis. Pathologic changes in the kidneys were essentially similar in both groups and consisted of focal acute tubular necrosis, affecting primarily the distal convoluted tubules and collecting ducts, dilatation of convoluted tubules, and formation of casts. These changes persisted as long as 29 days post CPDD therapy. In addition, the collecting ducts exhibited significant epithelial atypia. BUN and serum creatinine levels were elevated in both groups. The mean BUN/serum creatinine values were 54/2.2 mg/100 ml and 32/2.0 mg/100 ml for low and high-dose groups, respectively. Since the nephrotoxicity of CPDD is known to be dose-related, our findings suggest that mannitol-induced diuresis has considerably decreased the renal toxic damage of CPDD therapy in these patients.

High dose cis-platinum diammine dichloride: amelioration of renal toxicity by mannitol diuresis

A clinical trial was undertaken to improve the therapeutic index of cis-platinum diammine dichloride with a concomitantly administered mannitol induced diuresis. Sixty patients, heavily pretreated, were entered; fifty-one are evaluable. The technique of concomitant osmotic diuresis and CPDD administration is described in detail. Doses ranged from 3 mg/kg to 5 mg/kg. At 5 mg/kg, dose-limiting renal, marrow and ototoxicity were seen, and resulted in one drug death. Marrow toxicity was moderate. Renal toxicity was limited to transient elevations in serum creatinine levels, except in some patients who had renal impairment prior to CPDD treatment. These patients had moderate renal toxicity. Serial treatments as frequently as once every 3 weeks were used to maintain responses. Serial high dose CPDD produced only mild renal dysfunction. Ototoxicity, usually subclinical, was quantitated audiometrically, and found to be dose related, but not clinically prohibitive at 4 mg/kg or less. The overall response rate (PR/MR) was 42%. Clinically significant responses in epidermoid carcinoma of the head and neck, adenocarcinoma of the ovary, and germ cell tumors of the testis were seen. All six responding patients with germ cell tumor of the testis, had been resistant to low dose (1mg/kg) CPDD. Two responding patients with ovarian adenocarcinoma had been resistant to alkylating agents.

Comparison of the combination of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and vincristine with two dose schedules of 5-(3,3-dimethyl-1-triazino) imidazole 4-carboxamide (DTIC) in the treatment of disseminated malignant melanoma

One hundred twenty patients with inoperable metastatic malignant melanoma were randomly allocated to treatment with either a combination of BCNU 150 mg/m2 and vincristine 2 mg/m2 given every 30 days, or one of two regimens of DTIC: 300 mg/m2/day x 6 or 100 mg/m2/8 hours x 18 given every 30 days. Eight of the 51 (16%) patients who were originally treated with the BCNU and vincristine combination had 50% or more objective tumor regression, compared to 6 out of 25 (24%) patients treated with daily injections of DTIC, and 6 out of 21 (29%) patients treated with DTIC injections every 8 hours. The median duration of response to the BCNU and vincristine combination was 60 days, and the median duration of survival from initiation of treatment was 6.5 months in the responders and 3.3 months in the nonresponders. The median duration of response was 90 and 100 days for the daily and 8-hour regimens of DTIC respectively, andthe median duration of survival from commencement of treatment was 8.5 months for the responders and 3.5 months for the nonresponders. None of the 43 patients who failed to respond to the initial treatment program or whose disease progressed after initial improvement responded to the alternate treatment regimen.

Lymphadenopathy due to toxoplasmosis

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