[The concept of interstitial pneumonia with autoimmune features (IPAF)]

Interstitial lung diseases (ILD) are a heterogeneous group of respiratory diseases often related to connective tissue diseases. Some patients will develop an ILD with autoimmune features without reaching the recommended criteria for autoimmune diseases. Their management is difficult because they have both features for idiopathic and connective tissue disease. To better identify these patients, the concept of interstitial pneumonia with autoimmune features (IPAF) has been created. The diagnosis relies on ILD without identified cause and the presence of at least one defined criterion among 2 of the 3 following domains: clinic, serologic, and morphologic. The mean age at diagnosis is 60, a sex ratio of 1/1, and depending on the authors close to 20% of patients with IPAF will develop a connective tissue disease according to the international criterion. Their prognosis is better than for patients with idiopathic ILD and with an average 5-year survival of 70%. Older age at diagnosis, a pattern of usual interstitial pneumonia, and an impaired diffusing capacity for carbon monoxide have been identified as poor prognosis factors. The treatment relies on usual care for chronic respiratory diseases and is often associated with immunosuppressive and/or antifibrotic therapies. The objective of this classification is to better characterize these patients and improve their management.

Oral health status and barriers to oral healthcare among children with cerebral palsy attending a health care center in Kampala, Uganda

BACKGROUND

Cerebral palsy (CP) is a non-progressive neuromuscular condition diagnosed in childhood. CP as a form of disability, does not cause any specific oral disease. However, some oral conditions are more commonly associated with people with CP compared to the general population. The overarching aim of the current study was to determine the oral hygiene status, gingival status, and the prevalence of dental caries in children with CP attending a leading hospital institution for children with disabilities in Kampala, Uganda. Additionally, we determined the barriers faced by children with CP in accessing oral healthcare.

METHODS

This cross-sectional study was carried out at the Comprehensive Rehabilitation Services Uganda hospital in Kampala, Uganda. Our study population consisted of a convenient sample of 90 children diagnosed with CP aged 3-17 years and their caregivers. A validated and interviewer administered structured questionnaire was used to collect socio-demographic data of the participants. A modified World Health Organization oral health assessment form for those aged 3-17 years was used to gather data on oral health status (plaque score, gingival bleeding and dental caries.) The data was subjected to statistical tests with critical value set up at 5%.

RESULTS

Only 32.2% of the children evaluated had adequate oral hygiene, while 44.4% of the children experienced gingival bleeding. The prevalence of dental caries for both deciduous and permanent dentition was 63.3%, with DMFT values of 3.8 ± 4.5. The most common barrier reported by the caregivers was the challenge in modality of transportation availability from the children's homes to the health facilities (34.4%).

CONCLUSIONS

Children with CP in the study population have a significant prevalence of oral diseases and face several barriers to oral healthcare. Results from this study aim to provide relevant support to advocate for a nationwide change in policy to improve access to dental care to decrease the burden of oral diseases in children with special healthcare needs.

Stereotactic body radiation therapy (SBRT) as salvage treatment for early stage lung cancer with interstitial lung disease (ILD): An observational and exploratory case series of non-asian patients

Interstitial lung disease (ILD) can coexist with early-stage lung cancer (LC) and may compromise surgery and worsen patients' outcomes. Stereotactic body radiation therapy (SBRT) is the gold standard treatment for medically inoperable early-stage lung cancer, but radiation therapy is contra-indicated for patients with ILD because of the higher risk of severe radiation-induced pneumonitis. SBRT may spare healthy lung tissue, but data are scarce in this rare population. Our exploratory case series aimed to retrospectively identify patients treated with SBRT in this setting: 19 patients were diagnosed with early-stage LC-ILD over the past 6 years and 9 received SBRT. Most of them were smokers with a median age of 71, 4 had no pathological documentation. After SBRT, 5 patients had grade I-II respiratory adverse events (AEs), but none had treatment-related grade III-IV respiratory AEs. Two patients died within 6 months of SBRT, and for both, death was related to metastatic relapse. In this case series, the radiological evolution of ILD before radiotherapy and the evolution of the radiotherapy scar on CT-Scan were also explored with different evolutionary models. This exploratory study shows available data that could be studied in a larger retrospective cohort to identify risk factors for SBRT in the LC-ILD population. The use of dosimetric data as a risk factor for SBRT should be done with cautiousness due to heterogeneous and complex dose delivery and different fractionation schedule.

Evaluation of the frequency and factors predictive of hernia incarceration following transjugular intrahepatic portosystemic shunt placement

AIM

To examine the frequency and predictive factors for bowel incarceration following transjugular intrahepatic portosystemic shunts (TIPS) placement to treat refractory cirrhosis-induced ascites.

MATERIALS AND METHODS

Ninety-nine patients with known hernias at the time of TIPS placement were identified. Their electronic medical records were reviewed and pertinent pre-procedural, procedural, and outcome variables were recorded. Patients were divided between those that suffered incarceration (study group) and a control group of those with a hernia who did not suffer incarceration.

RESULTS

Twelve of the 99 patients (12.1%) suffered hernia incarceration, of which seven (7.1%) suffered incarceration in the first 90 days. One patient who suffered incarceration ultimately died from complications of the incarceration. When comparing all patients who suffered incarceration to controls, incarceration patients were found to have significantly higher albumin levels (mean 3.13 versus 2.73, p=0.02). When just considering those who had incarcerations in the first 90 days to controls, incarceration patients were less likely to have improvement in their ascites (p=0.04).

CONCLUSIONS

Incarcerated hernias occur frequently after TIPS placement and can lead to significant morbidity and mortality. Clinicians should be aware of this complication and counsel patients on presenting symptoms prior to placement.

Binding SNOMED CT Terms to Archetype Elements

Introduction: This article is part of the Focus Theme of Methods of Information in Medicine on “Managing Interoperability and Complexity in Health Systems”.

Background: The proliferation of archetypes as a means to represent information of Electronic Health Records has raised the need of binding terminological codes – such as SNOMED CT codes – to their elements, in order to identify them univocally. However, the large size of the terminologies makes it difficult to perform this task manually.

Objectives: To establish a baseline of results for the aforementioned problem by using off-the-shelf string comparison-based techniques against which results from more complex techniques could be evaluated.

Methods: Nine Typed Comparison Methods were evaluated for binding using a set of 487 archetype elements. Their recall was calculated and Friedman and Nemenyi tests were applied in order to assess whether any of the methods outperformed the others.

Results: Using the qGrams method along with the ‘Text’ information piece of archetype elements outperforms the other methods if a level of confidence of 90% is considered. A recall of 25.26% is obtained if just one SNOMED CT term is retrieved for each archetype element. This recall rises to 50.51% and 75.56% if 10 and 100 elements are retrieved respectively, that being a reduction of more than 99.99% on the SNOMED CT code set.

Conclusions: The baseline has been established following the above-mentioned results. Moreover, it has been observed that although string comparison-based methods do not outperform more sophisticated techniques, they still can be an alternative for providing a reduced set of candidate terms for each archetype element from which the ultimate term can be chosen later in the more-than-likely manual supervision task.

Increased Systemic Cytokine/Chemokine Expression in Asthmatic and Non-asthmatic Patients with Bacterial, Viral or Mixed Lung Infection

This study was aimed to determine the profiles of serum cytokines (IL-1β, TNF-α, IL-4, IL-5) and chemokines (MCP-1: monocyte chemoattract protein-1 and RANTES: regulated on activation normal T cell expressed and secreted) in individuals with an asthmatic versus a non-asthmatic background with bacterial, viral or mixed acute respiratory infection. Asthmatic (n = 14) and non-asthmatic (n = 29) patients with acute viral, bacterial or mixed (bacterial and viruses) respiratory infection were studied. Patients were also analysed as individuals with pneumonia or bronchitis. Healthy individuals with similar age and sex (n = 10) were used as controls. Cytokine/chemokine content in serum was determined by ELISA. Increased cytokine/chemokine concentration in asthmatic and non-asthmatic patients was observed. However, higher concentrations of chemokines (MCP-1 and RANTES) in asthmatic patients infected by viruses, bacteria or bacteria and viruses (mixed) than in non-asthmatic patients were observed. In general, viral and mixed infections were better cytokine/chemokine inducers than bacterial infection. Cytokine/chemokine expression was similarly increased in both asthmatic and non-asthmatic patients with pneumonia or bronchitis, except that RANTES remained at normal levels in bronchitis. Circulating cytokine profiles induced by acute viral, bacterial or mixed lung infection were not related to asthmatic background, except for chemokines that were increased in asthmatic status.

Nitric oxide as a mediator of fructose 1,6-bisphosphate protection in galactosamine-induced hepatotoxicity in rats

Fructose 1,6-bisphosphate (F1,6BP) has been widely used as a therapeutic agent for different harmful conditions in a variety of tissues. The hypothesis of the present work was that the increase in nitric oxide production and the prevention of oxidative stress induced by exogenous F1,6BP mediate its protective effect against the hepatotoxic action of GalN. Experimental groups used were sham, F1,6BP (2g/kg bw i.p.), GalN (0.4g/kg bw i.p), l-NAME (10mg/kg bw i.v.), F1,6BP+GalN, l-NAME+GalN and l-NAME+F1,6BP+GalN. Animals were killed after 24h of bolus administration. F1,6BP induced an increase in NO and the redox ratio (GSH/GSSG) in liver. Western blot assays pointed to overexpression of liver eNOS in F1,6BP-treated rats. The hepatic injury induced by GalN increased transaminases in plasma and decreased the reduced/oxidized glutathione ratio in liver. The concomitant administration of F1,6BP reversed this damage, while the addition of l-NAME worsened the liver injury. We provided evidence that this F1,6BP-induced protection may be related to the increase in NO production through the positive modulation of eNOS, and the increase in intracellular reduced glutathione, thus providing a higher reducing capacity.

Milk casein and fatty acid fractions in early lactation are affected by nutritional regulation of body condition score at the beginning of the transition period in primiparous and multiparous cows under grazing conditions

The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving (-30 days) induced by a differential nutritional management, parity and week of lactation (WOL) on milk yield and composition, and milk casein and fatty acid composition. Primiparous and multiparous Holstein cows with high BCS (PH, n = 13; MH, n = 9) and low BCS (PL, n = 9; ML = 8) under grazing conditions were sampled at WOL 2 and 8 (before and after peak of lactation). Milk yield was greater in multiparous than in primiparous cows and tended to decrease from WOL 2 to 8 only in ML cows. Milk protein, fat and casein yields were greater in multiparous than in primiparous cows and decreased from WOL 2 to 8. Milk casein concentration in milk protein was greater in MH cows than in ML, PH and PL cows at WOL 2. Milk κ-casein was greater, and β-casein was less in multiparous than in primiparous cows. As lactation progressed, proportion of casein fractions were not altered. Only κ-casein fraction was affected by BCS at -30 days as PL showed a higher concentration than PH. The de novo (4:0-15:1) and mixed-origin fatty acids (16:0-16:1) in milk fat increased, whereas preformed fatty acids (≥17:0) decreased from WOL 2 to 8. Saturated (SAT) fatty acids tended to be greater and monounsaturated fatty acids (MUFA) were less in multiparous than in primiparous cows. High-BCS cows had greater concentrations of polyunsaturated (PUFA), conjugated linoleic acid (CLA) as well as n-6 and n-3 fatty acids in milk fat than low-BCS cows. The results indicate that casein and fatty acid fractions in milk were affected by parity and may be modified by a differential nutritional management during the pre-calving period (BCS at -30 days) in cows under grazing conditions.

Fructose 1,6-bisphosphate reduced TNF-alpha-induced apoptosis in galactosamine sensitized rat hepatocytes through activation of nitric oxide and cGMP production

Fructose 1,6-P2 (F1,6BP) protects rat liver against experimental hepatitis induced by galactosamine (GalN) by means of two parallel effects: prevention of inflammation, and reduction of hepatocyte sensitization to tumour necrosis factor-alpha (TNF-alpha). In a previous paper we reported the underlying mechanism involved in the prevention of inflammation. In the present study, we examined the intracellular mechanisms involved in the F1,6BP inhibition of the apoptosis induced by TNF-alpha in parenchyma cells of GalN-sensitized rat liver. We hypothesized that the increased nitric oxide (NO) production in livers of F1,6BP-treated rats mediates the antiapoptotic effect. This hypothesis was evaluated in cultured primary rat hepatocytes challenged by GalN plus tumour necrosis factor-alpha (GalN+TNF-alpha), to reproduce in vitro the injury associated with experimental hepatitis. Our results show a reduction in apoptosis concomitant with an increase in NO production and with a reduction in oxidative stress. In such conditions, guanylyl cyclase is activated and the increase in cGMP reduces the TNF-alpha-induced apoptosis in hepatocytes. These results provide new insights in the protective mechanism activated by F1,6BP and confirm its interest as a hepatoprotective agent.

Fructose 1,6-bisphosphate prevented endotoxemia, macrophage activation, and liver injury induced by D-galactosamine in rats

OBJECTIVE

Fructose 1,6-bisphosphate (F1,6BP) protects organs against a wide range of challenges involving inflammation. We hypothesized that the primary action of F1,6BP is to prevent macrophage activation and cytokine release. Our aim was to determine the tissue and cellular targets for this bisphosphorylated sugar and to provide new insights into its mechanisms of action.

DESIGN

Prospective, controlled laboratory study.

SETTING

Animal resource facilities and research laboratory.

SUBJECTS

Male Sprague-Dawley rats (200-250 g body weight).

INTERVENTIONS

The protective action of F1,6BP was analyzed in galactosamine (GalN)-induced hepatitis in rats. The in vivo effects of F1,6BP were evaluated by changes in transaminase activities, blood endotoxins, and tumor necrosis factor (TNF)-alpha production in GalN-challenged rats. The targets of F1,6BP to reduce macrophage response to lipopolysaccharide (LPS) were determined by correlation between changes in TNF-alpha production and K+ fluxes through cell membrane in primary cultures of Kupffer cells.

MEASUREMENTS AND MAIN RESULTS

The in vivo results indicate that F1,6BP treatment prevented GalN-induced injury in liver parenchymal cells. This protection was mainly associated with a reduction of the inflammatory response. F1,6BP prevention of GalN-induced endotoxemia correlated with preclusion of mast cell degranulation and histamine release that preceded the increased plasma endotoxins and liver production of TNF-alpha. In addition, F1,6BP treatment decreased sensitivity to LPS, which reduced the GalN-induced increase in TNF-alpha. The in vitro results show that F1,6BP inhibited Kupffer cell response and reduced TNF-alpha production by preventing LPS-induced K+ channel activation.

CONCLUSIONS

The role of exogenous F1,6BP as a K+ channel modulator underlies its antihistaminic and anti-inflammatory action and increases its interest as a protective compound.

Aspirin inhibits NF-κB activation in a glycolysis-depleted lung epithelial cell line

Inhibition of glycolysis at the phosphofructo-1-kinase step slows cell growth. For this reason, overexpression of fructose-2,6-bisphosphatase is a potential target for antineoplasic treatments. However, therapeutic objectives may be compromised by side effects of glycolysis restriction, including enhanced resistance to oxidants and tumor necrosis factor-alpha (TNF-alpha), as well as increased activity of the nuclear factor kappa B (NF-kappaB). In this study we evaluated aspirin as an adjuvant drug for glycolysis restriction by overexpression of fructose-2,6-bisphosphatase. The effect of aspirin on antioxidant defences and NF-kappaB activity were evaluated both in control cells and in fructose-2,6-bisphosphatase-overexpressing cells. Interestingly, aspirin-induced inhibition of NF-kappaB activity was greater in transfectants with restricted glycolysis than in control cells. Our results indicate that aspirin is a suitable complement to therapy based on glycolysis restriction to overcome resistance associated with increased NF-kappaB activity and oxidative stress.

The pathology of peracute experimental Clostridium perfringens type D enterotoxemia in sheep

The pathological findings in sheep with peracute experimental Clostridium perfringens type D enterotoxemia are described. Of 16 animals inoculated intraduodenally with a whole culture of this microorganism and a starch solution in the abomasum, 12 developed clinical signs including increased respiratory efforts, recumbency, paddling, bleating, convulsions, blindness, and opisthotonus. Diarrhea was not observed in any of the animals. The time lapse between the beginning of intraduodenal infusion and onset of clinical signs varied between 30 minutes and 26 hours, and the clinical course varied between 1 and 9 hours. Gross postmortem changes were observed in these 12 animals and included pulmonary edema; excess pericardial, peritoneal, or pleural fluid with or without strands of fibrin; liquid small intestinal contents; leptomeningeal edema; cerebellar coning; and subcapsular petechiae on kidneys. Histological changes consisted of severe edema of pleura and interlobular septa and around blood vessels and airways and acidophilic, homogeneous, proteinaceous perivascular edema in the brain. Five of 12 animals (42%) with clinical signs consistent with enterotoxemia lacked specific histological lesions in the brain. None of the intoxicated or control animals developed nephrosis. Glucose was detected in the urine of 3 of 6 animals that were tested for this analyte. These results stress the importance of the use of histological examination of the brain, coupled with epsilon toxin detection, for a definitive diagnosis of C. perfringens type D enterotoxemia in sheep.

Receptor-mediated gene transfer vectors: progress towards genetic pharmaceuticals

Although specific delivery to tissues and unique cell types in vivo has been demonstrated for many non-viral vectors, current methods are still inadequate for human applications, mainly because of limitations on their efficiencies. All the steps required for an efficient receptor-mediated gene transfer process may in principle be exploited to enhance targeted gene delivery. These steps are: DNA/vector binding, internalization, subcellular trafficking, vesicular escape, nuclear import, and unpacking either for transcription or other functions (i.e., antisense, RNA interference, etc.). The large variety of vector designs that are currently available, usually aimed at improving the efficiency of these steps, has complicated the evaluation of data obtained from specific derivatives of such vectors. The importance of the structure of the final vector and the consequences of design decisions at specific steps on the overall efficiency of the vector will be discussed in detail. We emphasize in this review that stability in serum and thus, proper bioavailability of vectors to their specific receptors may be the single greatest limiting factor on the overall gene transfer efficiency in vivo. We discuss current approaches to overcome the intrinsic instability of synthetic vectors in the blood. In this regard, a summary of the structural features of the vectors obtained from current protocols will be presented and their functional characteristics evaluated. Dissecting information on molecular conjugates obtained by such methodologies, when carefully evaluated, should provide important guidelines for the creation of effective, targeted and safe DNA therapeutics.

Glutathione content and adaptation to endogenously induced energy depletion in Mv1Lu cells

Transfection of genes that code for enzymes of energy metabolism provides alternative models to study the adaptive response to energy restriction induced by endogenous changes instead of by unfavorable environmental conditions. Overexpression of the glycolytic enzyme fructose-2,6-bisphosphatase reduced the content of fructose 2,6-bisphosphate, inducing energy limitation in the mink lung epithelial cell line Mv1Lu. This metabolic stress reduced the ATP available in transfected cells by 20%, which downregulated active ion transport and protein turnover. Ion homeostasis and cell function require concomitant reductions in cell membrane ion permeability and protein damage. Our results indicate that glutathione content linked these features of the adaptive response to the endogenously induced metabolic downregulation.

Overexpression of fructose 2,6-bisphosphatase decreases glycolysis and delays cell cycle progression

The ability to overexpress 6-phosphofructo-2-kinase/fructose 2, 6-bisphosphatase (PFK-2)/(FBPase-2) or a truncated form of the enzyme with only the bisphosphatase domain allowed us to analyze the relative role of the kinase and the bisphosphatase activities in regulating fructose 2,6-bisphosphate (Fru-2,6-P(2)) concentration and to elucidate their differential metabolic impact in epithelial Mv1Lu cells. The effect of overexpressing PFK-2/FBPase-2 resulted in a small increase in the kinase activity and in the activity ratio of the bifunctional enzyme, increasing Fru-2,6-P(2) levels, but these changes had no major effects on cell metabolism. In contrast, expression of the bisphosphatase domain increased the bisphosphatase activity, producing a significant decrease in Fru-2,6-P(2) concentration. The fall in the bisphosphorylated metabolite correlated with a decrease in lactate production and ATP concentration, as well as a delay in cell cycle. These results provide support for Fru-2,6-P(2) as a regulator of glycolytic flux and point out the role of glycolysis in cell cycle progression.

Transgenic overexpression of caveolin-3 in skeletal muscle fibers induces a Duchenne-like muscular dystrophy phenotype

It recently was reported that Duchenne muscular dystrophy (DMD) patients and mdx mice have elevated levels of caveolin-3 expression in their skeletal muscle. However, it remains unknown whether increased caveolin-3 levels in DMD patients contribute to the pathogenesis of DMD. Here, using a genetic approach, we test this hypothesis directly by overexpressing wild-type caveolin-3 as a transgene in mice. Analysis of skeletal muscle tissue from caveolin-3- overexpressing transgenic mice reveals: (i) a dramatic increase in the number of sarcolemmal muscle cell caveolae; (ii) a preponderance of hypertrophic, necrotic, and immature/regenerating skeletal muscle fibers with characteristic central nuclei; and (iii) down-regulation of dystrophin and beta-dystroglycan protein expression. In addition, these mice show elevated serum creatine kinase levels, consistent with the myo-necrosis observed morphologically. The Duchenne-like phenotype of caveolin-3 transgenic mice will provide an important mouse model for understanding the pathogenesis of DMD in humans.

Medicamentos genéricos: uma alternativa para o mercado brasileiro

A análise das características da indústria farmacêutica no mundo e os aspectos mercadológicos desse segmento no Brasil deixam evidentes a dependência externa e a oligopolização, com predomínio de empresas de caráter mutinacional, refletindo uma tendência mundial. As iniciativas governamentais recentes no Brasil, com o objetivo de diminuir essa dependência, aliadas à gravidade da questão dos preços e custos de medicamentos no Brasil, comparados a preços mundiais, fundamentam a proposta de avaliar os medicamentos genéricos como uma alternativa viável para o mercado brasileiro. Um dos aspectos mais alarmantes é a verificação do superfaturamento de matérias-primas evidenciada pelos denominados "preços de transferência", prática constatada em diversos países. Analisando os conceitos internacionais sobre medicamentos genéricos, denominação genérica e equivalência farmacêutica, com base ainda em recomendações da Organização Mundial da Saúde e avaliando as experiências de diversos países, são propostas uma série de medidas destinadas a implementar, gradativamente, uma política de medicamentos genéricos bioequivalentes e intercambiáveis como um dos mecanismos de regulação do mercado brasileiro.

ENERGY METABOLISM BY TROUT RED BLOOD CELLS: SUBSTRATE UTILISATION

The present study investigates energy metabolism by trout red blood cells. It is shown that they are able to use pyruvate at physiological concentrations as an aerobic source of energy. Moreover, microcalorimetric data suggest that trout erythrocytes are also able to use internal substrates, at least when maintained in vitro. Although the actual nature of these substrates has not been elucidated, glycogen appears to be the most probable. The relationship between heat dissipation and oxygen consumption suggests that most of the oxygen is used to oxidize substrates, and the inhibition of respiratory activity by antimycin A indicates that there is no substantial utilisation of non-respiratory oxygen. However, the oxygen uptake by these cells does not appear to be related to substrate utilisation, measured from transformation of labelled molecules (either pyruvate or glucose); this may be due to mixing of labelled compounds with non-labelled molecules in the intracellular pools, because of the low metabolic rate of these cells.

Prolonged anti-emetic activity and 5-HT3-receptor antagonism by BRL 46470 in conscious ferrets

The anti-emetic activity of oral and intravenously-administered BRL 46470 (endo-N-(8-methyl-8-azabicyclo[3.2.1]oct-3yl)-2,3-dihydro-3,3- dimethyl-indole-1-carboxamide HCl) has been assessed in conscious ferrets. BRL 46470 (0.05-0.5 mg kg-1, p.o.) dose-dependently prevented emesis evoked over a 2 h period by total body X-irradiation. This anti-emetic activity occurred with oral or intravenously-administered BRL 46470 even when dosed 3-4 h before radiation. In conjunction with data obtained in other species, we conclude that BRL 46470 has a potent and long-lasting ability to antagonize actions that are mediated by the 5-HT3 receptor in-vivo.

Idiopathic osteoporosis during pregnancy

Among the idiopathic forms of osteoporosis, the one developing during pregnancy is the least common and scarcely studied. Poorly understood, it seems to stem from transient failure of calcitropic hormones and decreased osteoblast activity. A 25-year-old patient presented with coxofemoral pain during the last three months of pregnancy, followed by multiple vertebral compression fractures at postpartum. Laboratory, radiological, densitometric and histological examinations led to a diagnosis of idiopathic osteoporosis in pregnancy, once other causes of osteopenia had been ruled out. Bone densitometries performed 12 and 24 months later showed an increase in mineral density, thus demonstrating the self-limited nature of this entity.

Microcalorimetric evaluation of the effects of methotrexate and 6-thioguanine on sensitive T-lymphoma cells and on a methotrexate-resistant subline

Isothermal microcalorimetry was used in order to continuously monitor and quantitatively assess the action of two antineoplastic drugs, methotrexate (MTX) and 6-thioguanine (6-TG), on a human T-lymphoma cell line, CCRF-CEM. The results with MTX were compared with data from experiments with a MTX-resistant subline, CEM/MTX. The slope of the power-time curve after drug injection relative to that obtained during unperturbed growth, was used to construct dose-response curves. The normal cell line was characterized by a D50 value (i.e., the dose producing half the maximal response) of 0.05 microM for MTX and 0.38 microM for 6-TG. For the MTX-resistant subline the D50 value was 8 microM of MTX. Comparisons of the continuous power-time curves showed the inhibitory effect of 6-TG to be faster than that of MTX.

The relative potency of pentobarbital in suppressing the kainic acid- or the N-methyl-D-aspartic acid-induced enhancement of cGMP in cerebellar cells

Primary cultures of rat cerebellar cells were pretreated with various dosages of pentobarbital before the addition of kainic acid or N-methyl-D-aspartic acid in order to assess effects of this drug on the enhancement of cyclic guanosine-3',5'-phosphate (cyclic GMP) mediated by these excitatory agonists. Pentobarbital significantly suppressed kainic acid-induced increases in this cyclic nucleotide at concentrations as low as 5 microM but was only effective in suppressing the N-methyl-D-aspartic acid enhancement at dosages of 100 microM or greater. These data suggest that this barbiturate is a more effective depressant of the stimulatory effects of kainic acid as compared to N-methyl-D-aspartic acid.

5-Hydroxytryptamine (5-HT3) receptor antagonists. 1. Indazole and indolizine-3-carboxylic acid derivatives

Metoclopramide (1) is a gastric motility stimulant and a weak dopamine and 5-HT3 receptor antagonist. Conformational restriction of the (diethylamino)ethyl side chain of 1 in the form of the azabicyclic tropane gave 3, a very potent gastric motility stimulant and 5-HT3 receptor antagonist but devoid of significant dopamine receptor antagonist properties. Subsequent alteration of the aromatic nucleus led to the identification of indazoles 6a-h, and 1- and 3-indolizines 7b-d and 8, and imidazo[1,5-alpha]pyridines 9 and 10, as potent 5-HT3 receptor antagonists devoid of either dopamine antagonist or gastric motility stimulatory properties. Further conformational restriction of the side chain identified quinuclidine 11 and isoquinuclidine 12 as potent 5-HT3 receptor antagonists which mimic the distorted chair conformation of the tropane with, in the case of 11, the N-methyl group axial. From these series, 6g (BRL 43694) was found to be both potent and selective and has been shown to be a very effective antiemetic agent against cytotoxic drug induced emesis both in the ferret and in man.

5-Hydroxytryptamine (5-HT3) receptor antagonists. 2. 1-Indolinecarboxamides

Indazole 1 has previously been shown to be a potent and selective 5-HT3 receptor antagonist. A novel series of potent 5-HT3 receptor antagonists, 1-indolinecarboxamides 2a-q and 1-indolecarboxamides 3b,i,j,k, is described. The activity of the indolines suggests that aromaticity of the 5-membered ring is not an essential requirement for potency provided that an "in plane" orientation of the carbonyl group is favored. Upon the basis of this hypothesis indene 9 was prepared in which the "in plane" orientation of the carbonyl group is maintained by conjugation with the aromatic ring through the sp2 hybridized carbon. It was also found to be a potent 5-HT3 receptor antagonist.