Interference Screw versus Cement Fixation in Anterior Cruciate Ligament Soft Tissue Grafts: A Biomechanical Study.

Shortcomings of fixation have been reported as a source of graft failure in anterior cruciate ligament (ACL) reconstruction. While interference screws have long been used as fixation devices for ACL reconstruction, they are not without complications. Previous studies have highlighted the use of bone void filler as a fixation method; however, no biomechanical comparisons using soft tissue grafts with interference screws exist to our knowledge. The purpose of this study is to evaluate the fixation strength of a calcium phosphate cement bone void filler compared with screw fixation in an ACL reconstruction bone replica model with human soft tissue grafts. In total, 10 ACL grafts were constructed using semitendinosus and gracilis tendons harvested from 10 donors. Grafts were affixed with either an 8-10 mm × 23 mm polyether ether ketone interference screw (n = 5) or with approximately 8 mL of calcium phosphate cement (n = 5) into open cell polyurethane blocks. Graft constructs were tested to failure in cyclic loading under displacement control at a rate of 1 mm per second. When compared with screw construct, the cement construct showed a 978% higher load at yield, 228% higher load at failure, 181% higher displacement at yield, 233% higher work at failure, and a 545% higher stiffness. Normalized data for the screw constructs relative to the cement constructs from the same donor showed 14 ± 11% load at yield, 54 ± 38% load at failure, and 172 ± 14% graft elongation. The results of this study indicate that cement fixation of ACL grafts may result in a stronger construct compared with the current standard of fixation with interference screws. This method could potentially reduce the incidence of complications associated with interface screw placement such as bone tunnel widening, screw migration, and screw breakage.

Reconstruction of Acquired Defects of the External Genitalia: A 24-Patient, Single-Institution Experience.

PURPOSE: Patients undergoing resection of the external genitalia are often faced with significant deformity and decreased quality of life. Plastic surgeons are tasked with the challenge of reconstructing these defects to minimize morbidity and increase patients' quality of life. The authors have set out to investigate the efficacy of local fasciocutaneous and pedicled perforator flaps in external genital reconstruction. METHODS: A retrospective review was conducted of all patients undergoing reconstruction of acquired defects of the external genitalia from 2017 to 2021. In total, 24 patients met inclusion criteria for the study. Patients were allocated into 2 cohorts: patients with defects reconstructed using local fasciocutaneous flaps (FF) versus patients with defects reconstructed using pedicled islandized perforator flaps (PF). Comorbid conditions, ablative procedures, operative times, flap size, and complications were compared across all groups. Fisher exact test was used to analyze differences in comorbidities, while independent t tests were used to analyze age, body mass index, operative time, and flap size. Significance was set at P < 0.05. RESULTS: Of the 24 patients included in the study, 6 underwent reconstruction with islandized PFs (either profunda artery perforator or anterolateral thigh), and 18 underwent reconstruction with FFs. The most common indication for reconstruction was vulvectomy for vulvar cancer, followed by radical debridement for infection, and lastly penectomy for penile cancer. The PF cohort had a significantly higher percentage of previously irradiated patients (50% vs 11.1%, P = 0.019). Although mean flap size was larger in the PF cohort, this difference did not reach statistical significance (176 vs 143.4 cm2, P = 0.5). Perforator flaps had significantly longer operative times when compared with FFs (237.33 vs 128.99 minutes, P = 0.003). Average length of stay was 6.88 days in FF and 5.33 days in PF (P = 0.624). Complication profile including flap necrosis, wound healing delays, and infection were similar between groups despite a significantly higher rate of prior radiation in the PF cohort. CONCLUSIONS: Our data suggest that PFs such as profunda artery perforator and anterolateral thigh flaps are associated with longer operative times but may offer a suitable option for reconstruction of acquired defects of the external genital compared with local FFs, especially in the setting of prior radiation.

Absence of Increased Susceptibility to Acetaminophen-Induced Liver Injury in a Diet-Induced NAFLD Mouse Model.

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease and its influence on drug-induced liver injury (DILI) is not fully understood. We investigated whether NAFLD can influence acetaminophen (APAP [N-acetyl-p-aminophenol])-induced hepatotoxicity in a diet-induced obese (DIO) mouse model of NAFLD. The male C57BL/6NTac DIO mice, fed a high-fat diet for more than 12 weeks, developed obesity, hyperinsulinemia, impaired glucose tolerance, and hepatomegaly with hepatic steatosis, similar to human NAFLD. In the acute toxicity study after a single dose of APAP (150 mg/kg), compared with control lean mice, the DIO mice had decreased serum transaminase levels and less severe hepatocellular injury. The DIO mice also had altered expression of genes related to APAP metabolism. Chronic APAP exposure for 26 weeks did not predispose the DIO mice with NAFLD to more severe hepatotoxicity compared with the lean mice. These results suggested that the C57BL/6NTac DIO mouse model appears to be more tolerant to APAP-induced hepatotoxicity than lean mice, potentially related to altered xenobiotic metabolizing capacity in the fatty liver. Further mechanistic studies with APAP and other drugs in NAFLD animal models are necessary to investigate the mechanism of altered susceptibility to intrinsic DILI in some human NAFLD patients.

Proteolytic processing induces a conformational switch required for antibacterial toxin delivery.

Many Gram-negative bacteria use CdiA effector proteins to inhibit the growth of neighboring competitors. CdiA transfers its toxic CdiA-CT region into the periplasm of target cells, where it is released through proteolytic cleavage. The N-terminal cytoplasm-entry domain of the CdiA-CT then mediates translocation across the inner membrane to deliver the C-terminal toxin domain into the cytosol. Here, we show that proteolysis not only liberates the CdiA-CT for delivery, but is also required to activate the entry domain for membrane translocation. Translocation function depends on precise cleavage after a conserved VENN peptide sequence, and the processed ∆VENN entry domain exhibits distinct biophysical and thermodynamic properties. By contrast, imprecisely processed CdiA-CT fragments do not undergo this transition and fail to translocate to the cytoplasm. These findings suggest that CdiA-CT processing induces a critical structural switch that converts the entry domain into a membrane-translocation competent conformation.

Analytical Performances of the COVISTIXTM Antigen Rapid Test for SARS-CoV-2 Detection in an Unselected Population (All-Comers).

The performance and validity of the COVISTIXTM rapid antigen test for the detection of SARS-CoV-2 were evaluated in an unselected population. Additionally, we assessed the influence of the Omicron SARS-CoV-2 variant in the performance of this antigen rapid test. Swab samples were collected at two point-of-care facilities in Mexico City from individuals that were probable COVID-19 cases, as they were either symptomatic or asymptomatic persons at risk of infection due to close contact with SARS-CoV-2 positive cases. Detection of the Omicron SARS-CoV-2 variant was performed in 91 positive cases by Illumina sequencing. Specificity and sensitivity of the COVISTIXTM rapid antigen test was 96% (CI 95% 94-98) and 81% (CI 95% 76-85), respectively. The accuracy parameters were not affected in samples collected after 7 days of symptom onset, and it was possible to detect almost 65% of samples with a Ct-value between 30 and 34. The COVISTIXTM antigen rapid test is highly sensitive (93%; CI 95% 88-98) and specific (98%; CI 95% 97-99) for detecting Omicron SARS-CoV-2 variant carriers. The COVISTIXTM rapid antigen test is adequate for examining asymptomatic and symptomatic individuals, including those who have passed the peak of viral shedding, as well as carriers of the highly prevalent Omicron SARS-CoV-2 variant.

Efecto angiogénico comparado del celecoxib microencapsulado en PLGA v/s no encapsulado en un ensayo in vivo de angiogénesis / Comparative angiogenic effect of microencapsulated celecoxib in PLGA v/s non-encapsulated in an in vivo angiogenesis assay

RESUMEN: La angiogénesis es el proceso de formación de vasos sanguíneos a partir de otros formados previamente. Existen varios factores que están involucrados en el proceso, así como agentes capaces de modular distintas etapas de esta. Si bien, se ha observado que Celecoxib es capaz de inhibir la angiogénesis en distintos modelos, aún no se ha observado la potencial capacidad antiangiogénica de este agente cuando es microencapsulado en PLGA. Se incubaron huevos fertilizados y a las 48 horas se dividieron en 4 grupos para ser instilados con PBS (control), PLGA, Celecoxib 1000 ppm o Celecoxib 1000 ppm + PLGA. Se realizó un conteo de los vasos sanguíneos a las 48, 72 y 96 horas post aplicación de la solución a estudiar. Los resultados muestran que tanto Celecoxib como Celecoxib+PLGA reducen los vasos sanguíneos, manteniendo el mismo efecto a las 48, 72 y 96 horas y no existen diferencias significativas entre los dos tratamientos. Esto podría ser explicado por la concentración de Celecoxib usada o el margen de tiempo analizado, pudiendo encontrarse diferencias posteriores a este rango de tiempo o con concentraciones distintas.

SUMMARY: Angiogenesis is the process of blood vessel formation from previously formed ones. There are several factors involved in the process, as well as agents capable of modulating different stages of it. Although, it has been observed that Celecoxib is capable of inhibiting angiogenesis in different models, the potential antiangiogenic capacity of this agent has not yet been observed when it is microencapsulated in PLGA. Fertilized eggs were incubated and at 48 hours they were divided into 4 groups to be instilled with PBS (control), PLGA, Celecoxib 1000ppm or Celecoxib 1000 ppm + PLGA. A blood vessel count was performed at 48, 72 and 96 hours after application of the solution to be studied. The results show that both Celecoxib and Celecoxib + PLGA reduce blood vessels, maintaining the same effect at 48, 72 and 96 hours and there are no significant differences between the two treatments. This could be explained by the concentration of Celecoxib used or the time frame analyzed, being able to find differences after this time range or with different concentrations.

El límite de disfagia como prueba electromiográfica de detección del trastorno de deglución / Dysphagia limit as electromyographic test to detect swallowing disorders

Objetivo. Determinar la utilidad de la prueba electromiográfica conocida como 'límite de disfagia' en una cohorte de individuos con trastorno de deglución. Materiales y métodos. Se evaluaron 32 individuos sanos y 32 individuos con trastorno de deglución detectado mediante el cuestionario autosuministrado EAT-10 (Eating Assessment Tool-10), versión traducida y validada al español para Colombia. A todos los individuos se les aplicó la prueba límite de disfagia como método cuantitativo y no invasivo para evaluar la deglución mediante electromiografía de superficie con electrodos ubicados en el músculo submentalis y en el espacio cricotiroideo, utilizando un equipo de dos canales Cadwell Summit Sierra®. Se suministró agua cuyo volumen aumentó gradualmente: 5, 10, 15, 20 y 25 ml. Todos los sujetos fueron instruidos para deglutir el volumen total suministrado en un solo trago. Se determinó el número de pasos o bursts que requirió el individuo para ingerir todo el volumen de líquido. Los resultados de la prueba límite de disfagia se compararon entre los grupos. Se estableció correlación entre el EAT-10 y la prueba límite de disfagia. Se calculó la exactitud diagnóstica de la prueba límite de disfagia en cuanto sensibilidad, especificidad, valores predictivos, proporción de falsos positivos y fasos negativos. Resultados. Se encontró una buena exactitud diagnóstica de la prueba límite de disfagia para detectar trastorno de deglución. Se constató una correlación significativa entre el puntaje de la escala EAT-10 y el resultado de la prueba electrofisiológica límite de disfagia. Conclusión. Este estudio muestra que la prueba límite de disfagia tiene un buen rendimiento diagnóstico para detectar trastorno de deglución

Objective. To determine the usefulness of the electromyographic test known as the 'dysphagia borderline' in a cohort of individuals with swallowing disorder. Materials and methods. Thirty-two healthy individuals and 32 individuals with swallowing disorder detected by means of the self-supplied questionnaire EAT-10 (Eating Assessment Tool-10), a version translated and validated in Spanish for Colombia, were evaluated. All individuals underwent the dysphagia borderline test as a quantitative and non-invasive method to evaluate swallowing by means of surface electromyography with electrodes located in the submentalis muscle and in the cricothyroid space, using a two-channel Cadwell Summit Sierra® equipment. Water was supplied with gradually increasing volume: 5, 10, 15, 15, 20 and 25 ml. All subjects were instructed to swallow the total volume supplied in one gulp. The number of steps or bursts required by the individual to swallow the entire volume of liquid was determined. The results of the borderline dysphagia test were compared between groups. Correlations were established between the EAT-10 and the borderline dysphagia test. The diagnostic accuracy of the borderline dysphagia test was calculated in terms of sensitivity, specificity, predictive values, false-positive and false-negative rates. Results. A good diagnostic accuracy of the borderline dysphagia test for detecting swallowing disorder was found. A significant correlation was found between the EAT-10 scale score and the result of the electrophysiological borderline dysphagia test. Conclusion. This study shows that the borderline dysphagia test has a good diagnostic performance to detect swallowing disorder.

Incidencia de complicaciones post quirúrgicas en cirugía bucal / Incidence of post-surgical complications in oral surgery

OBJETIVO: El objetivo principal de este estudio fue determinar la incidencia de complicaciones post cirugía bucal. METODOLOGÍA: Se desarrolló un estudio observacional, descriptivo, con el uso del registro prospectivo de la totalidad de pacientes ingresados para cirugía bucal del Complejo Hospitalario San Borja-Arriarán durante doce meses de observación (abril 2017 a marzo 2018). RESULTADOS: La muestra estuvo conformada por 532 pacientes sometidos a procedimientos quirúrgicos de cirugía bucal y 29 casos de complicación postquirúrgica. La incidencia de complicaciones alcanzó un 5,5% y se observó de manera predominante en intervenciones de tipo exodoncia. La complicación mayormente observada fue la alveolitis alcanzando un 2,5% de las cirugías de terceros molares y un 3,7% de las exodoncias de otros dientes. Las hemorragias postoperatorias se observaron en un 1,1% de las cirugías de terceros molares. Otras complicaciones postquirúrgicas fueron abscesos de espacios faciales, parestesia del nervio alveolar inferior, hematomas, equimosis y periostitis. CONCLUSIÓN: Los resultados fueron similares a los reportados en la literatura tanto en su frecuencia como en el tipo de complicación.

OBJECTIVE: The main objective of this investigation was to determine the incidence of postoperative complications in oral surgery. MATERIALS AND METHODS: An observational and descriptive study was developed with the use of the prospective registry of the patients admitted for oral surgery in the San Borja Arriarán Hospital Complex for a twelve-month period of observation (April 2017 to March 2018). RESULTS: The sample consisted of 532 patients undergoing surgical procedures of oral surgery and 29 cases of postoperative complications. The incidence of complications reached 5,5% and it was observed predominantly in interventions of tooth extraction. The most commonly observed complication was dry socket, reaching 2,5% of third molar surgeries and 3,7% of extractions of other teeth. Postoperative hemorrhages were observed in 1,1% of third molar surgeries. Other postoperative complications were facial spaces abscesses, paresthesia of the inferior alveolar nerve, bruising, ecchymosis and periostitis. CONCLUSIONS: The results were similar to those reported in the literature both in their frequency and in the type of complication.

Infectious postoperative complications in oral surgery. An observational study.

BACKGROUND: The main objective of this investigation was to determine the incidence of infectious postoperative complications in oral surgery. MATERIAL AND METHODS: A observational and descriptive study was developed, with the use of prospective registry of the patients admitted for oral surgery at the San Borja Arriarán Hospital Complex during twelve months observation period (April 2017 to March 2018). RESULTS: The sample consisted of 532 patients undergoing surgical procedures of oral surgery and 19 cases of infectious postoperative complications. The incidence of complications reached 3,57% and it was observed predominantly in exodontic type interventions. The most commonly observed complication was dry socket, reaching 2,5% of third molar surgeries and 3,7% of extractions of other teeth. Other postoperative complication were 7 cases of facial spaces abscesses, also observed predominantly in exodontic type interventions. CONCLUSIONS: The results were similar to those reported in the literature both in their frequency and in the type of complication. Key words:Oral surgery, incidence, postoperative complications, dry socket, third molar.

Dental caries is associated with severe periodontitis in Chilean adults: a cross-sectional study.

BACKGROUND: The co-occurrence of caries and periodontitis and a possible association is still a matter of debate. Thus, the aim of the study was to determine the co-occurrence of caries and periodontitis in Chilean adults. METHODS: Evaluation of periodontal and dental status in 994 adults (35-44 years old) based on the First Chilean National Examination Survey 2007-2008. The prevalence of caries was defined as the percentage of participants with one or more teeth with untreated caries by using the D component of the DMFT index (DT ≠ 0). The prevalence of periodontitis was determined using standard case definitions for population-based surveillance of periodontitis described by the CDC-AAP. RESULTS: Individuals with caries had an approximately 40% higher prevalence of severe (29.3% vs 20.8%, p < 0.05) and a 13% higher prevalence of total periodontitis (89.3% vs 78.4%, p < 0.05) than those without caries. Ordinal logistic regression revealed a positive association between periodontitis and the number of teeth with caries (DT ≠ 0; 3 or 4 teeth with caries: OR 1.74; CI = 1.12-2.29 p < 0.05; 5 or more teeth with caries: OR 2.47; CI = 1.66-3.67 p < 0.01). CONCLUSION: Dental caries is associated with the severity and prevalence of periodontitis in Chilean adults. Individuals with 3 or more teeth with untreated caries are more likely to suffer from periodontal disease.

Interfacial water and its potential role in the function of sericin against biofouling.

Silk sericin is a globular protein whose resistance against fouling is important for applications in biomaterials and water-purification membranes. Here it is shown how sericin generates a water-exclusion zone that may facilitate antifouling behavior. Negatively charged microspheres were used to mimic the surface charge and hydrophobic domains in bacteria. Immersed in water, regenerated silk sericin formed a 100-µm-sized exclusion zone (for micron-size foulants), along with a proton gradient with a decrease of >2 pH-units. Thus, when in contact with sericin, water molecules near the surface restructure to form a physical exclusionary barrier that might prevent biofouling. The decreased pH turns the aqueous medium unviable for neutrophilic bacteria. Therefore, resistance to biofouling seems explainable, among other factors, on the basis of water-exclusionary phenomena. Furthermore, sericin may play a role in triggering the fibroin assembly process by lowering the pH to the required value.

Blocking Alcoholic Steatosis in Mice with a Peripherally Restricted Purine Antagonist of the Type 1 Cannabinoid Receptor.

Type 1 cannabinoid receptor (CB1) antagonists have demonstrated promise for the treatment of obesity, liver disease, metabolic syndrome, and dyslipidemias. However, the inhibition of CB1 receptors in the central nervous system can produce adverse effects, including depression, anxiety, and suicidal ideation. Efforts are now underway to produce peripherally restricted CB1 antagonists to circumvent CNS-associated undesirable effects. In this study, a series of analogues were explored in which the 4-aminopiperidine group of compound 2 was replaced with aryl- and heteroaryl-substituted piperazine groups both with and without a spacer. This resulted in mildly basic, potent antagonists of human CB1 (hCB1). The 2-chlorobenzyl piperazine, 25, was found to be potent ( Ki = 8 nM); to be >1000-fold selective for hCB1 over hCB2; to have no hERG liability; and to possess favorable ADME properties including high oral absorption and negligible CNS penetration. Compound 25 was tested in a mouse model of alcohol-induced liver steatosis and found to be efficacious. Taken together, 25 represents an exciting lead compound for further clinical development or refinement.

Thermolytic Degradation of Synthetic Cannabinoids: Chemical Exposures and Pharmacological Consequences.

Synthetic cannabinoids are manufactured clandestinely with little quality control and are distributed as herbal "spice" for smoking or as bulk compound for mixing with a solvent and inhalation via electronic vaporizers. Intoxication with synthetic cannabinoids has been associated with seizure, excited delirium, coma, kidney damage, and other disorders. The chemical alterations produced by heating these structurally novel compounds for consumption are largely unknown. Here, we show that heating synthetic cannabinoids containing tetramethylcyclopropyl-ring substituents produced thermal degradants with pharmacological activity that varied considerably from their parent compounds. Moreover, these degradants were formed under conditions simulating smoking. Some products of combustion retained high affinity at the cannabinoid 1 (CB1) and CB2 receptors, were more efficacious than (-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol (CP55,940) in stimulating CB1 receptor-mediated guanosine 5'-O-(3-thiotriphosphate) (GTPγS) binding, and were potent in producing Δ9-tetrahydrocannabinol-like effects in laboratory animals, whereas other compounds had low affinity and efficacy and were devoid of cannabimimetic activity. Degradants that retained affinity and efficacy also substituted in drug discrimination tests for the prototypical synthetic cannabinoid 1-pentyl-3-(1-naphthoyl)indole (JWH-018), and are likely to produce psychotropic effects in humans. Hence, it is important to take into consideration the actual chemical exposures that occur during use of synthetic cannabinoid formulations to better comprehend the relationships between dose and effect.

Carcinogenic risk of emerging persistent organic pollutant perfluorooctane sulfonate (PFOS): A proposal of classification.

Perfluoroalkyls are stable synthetic chemicals, able to repel oils, fats and water. These compounds have been used in the manufacturing of products such as Teflon®, lubricants, paints, fire-fighting foams, coatings for pans, carpets, clothes, and paperboard for packaging, among others. It is believed that populations are exposed constantly to them. Its regulation in the world is under development and several controversies are in the course of litigation. One occupational study shows bladder cancer risk. This paper intends to review scientific information on the most critical perfluoroalkyl compound and proposes a procedure to get a cancer-risk categorization which PFOS can cause to populations. METHODS: As a guiding axis, we used the IARC process for developing monographs of carcinogenic risks. We used the SIGN guides for evaluating the quality of studies in human populations; and finally, we used the Squire method for evaluating studies in laboratory animals. Inadequate evidence of carcinogenicity was found in human studies mainly due to chance, threshold effect and confounders. In experimental animal studies, inadequate evidence of carcinogenicity was found in view of the number of affected species, different types of neoplasms, dose-response relationship and genotoxicity found in in-vivo and in-vitro studies. In this proposal, we concluded that cancer risk for PFOS, according to the IARC method, is not classifiable as carcinogenic to humans (group 3).

AB-CHMINACA, AB-PINACA, and FUBIMINA: Affinity and Potency of Novel Synthetic Cannabinoids in Producing Δ9-Tetrahydrocannabinol-Like Effects in Mice.

Diversion of synthetic cannabinoids for abuse began in the early 2000s. Despite legislation banning compounds currently on the drug market, illicit manufacturers continue to release new compounds for recreational use. This study examined new synthetic cannabinoids, AB-CHMINACA (N-[1-amino-3-methyl-oxobutan-2-yl]-1-[cyclohexylmethyl]-1H-indazole-3-carboxamide), AB-PINACA [N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-pentyl-1H-indazole-3-carboxamide], and FUBIMINA [(1-(5-fluoropentyl)-1H-benzo[d]imadazol-2-yl)(naphthalen-1-yl)methanone], with the hypothesis that these compounds, like those before them, would be highly susceptible to abuse. Cannabinoids were examined in vitro for binding and activation of CB1 receptors, and in vivo for pharmacological effects in mice and in Δ(9)-tetrahydrocannabinol (Δ(9)-THC) discrimination. AB-CHMINACA, AB-PINACA, and FUBIMINA bound to and activated CB1 and CB2 receptors, and produced locomotor suppression, antinociception, hypothermia, and catalepsy. Furthermore, these compounds, along with JWH-018 [1-pentyl-3-(1-naphthoyl)indole], CP47,497 [rel-5-(1,1-dimethylheptyl)-2-[(1R,3S)-3-hydroxycyclohexyl]-phenol], and WIN55,212-2 ([(3R)-2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone, monomethanesulfonate), substituted for Δ(9)-THC in Δ(9)-THC discrimination. Rank order of potency correlated with CB1 receptor-binding affinity, and all three compounds were full agonists in [(35)S]GTPγS binding, as compared with the partial agonist Δ(9)-THC. Indeed, AB-CHMINACA and AB-PINACA exhibited higher efficacy than most known full agonists of the CB1 receptor. Preliminary analysis of urinary metabolites of the compounds revealed the expected hydroxylation. AB-PINACA and AB-CHMINACA are of potential interest as research tools due to their unique chemical structures and high CB1 receptor efficacies. Further studies on these chemicals are likely to include research on understanding cannabinoid receptors and other components of the endocannabinoid system that underlie the abuse of synthetic cannabinoids.

Cross-substitution of Δ9-tetrahydrocannabinol and JWH-018 in drug discrimination in rats.

Synthetic indole-derived cannabinoids, originally developed to probe cannabinoid CB1 and CB2 receptors, have become widely abused for their marijuana-like intoxicating properties. The present study examined the effects of indole-derived cannabinoids in rats trained to discriminate Δ(9)-tetrahydrocannabinol (Δ(9)-THC) from vehicle. In addition, the effects of Δ(9)-THC in rats trained to discriminate JWH-018 from vehicle were assessed. Adult male Sprague-Dawley rats were trained to discriminate 3mg/kg Δ(9)-THC or 0.3mg/kg JWH-018 from vehicle. JWH-018, JWH-073, and JWH-210 fully substituted in Δ(9)-THC-trained rats and Δ(9)-THC substituted in JWH-018-trained rats. In contrast, JWH-320, an indole-derived cannabinoid without affinity for CB1 receptors, failed to substitute for Δ(9)-THC. Pre-treatment with 1mg/kg rimonabant significantly reduced responding on the JWH-018-associated lever in JWH-018-trained rats. These results support the conclusion that the interoceptive effects of Δ(9)-THC and synthetic indole-derived cannabinoids show a large degree of overlap, which is predictive of their use for their marijuana-like intoxicating properties. Characterization of the extent of pharmacological differences among structural classes of cannabinoids, and determination of their mechanisms remain important goals.

Astrocytomas of the cerebral peduncle in children: surgical experience in seven patients.

OBJECTS: Cerebral peduncle tumors are rare in childhood but often consist of benign astrocytomas. Surgical resection, however, is considered to be detrimental because of the highly sensitive neural structures. These tumors are often treated by radiation therapy (RT). We resected such tumors in seven patients, whom we then followed up without adjuvant therapy. The surgical approach and postoperative course are analyzed. METHODS: Seven children, ranging in age from 4 to 16 years, were treated from 1993 to 2000. Tumors showed extension in various directions to the thalamus, pons and neighboring cisterns. All were treated by surgical resection through a subtemporal approach: total resection was achieved in three and subtotal resection in four. Operative complications were minimal. Two patients were worse after surgery, albeit temporarily, in motor, oculomotor or memory functions. All the tumors were benign astrocytomas. None of the patients received postoperative RT. Only one patient had a recurrence during the follow-up period, which ranged from 1 year to 8.5 years in duration. CONCLUSIONS: Benign astrocytomas of the cerebral peduncle are amenable to radical tumor resection by an appropriate surgical approach and with microsurgical techniques. Even following subtotal resection, these tumors frequently remain stable or involute. These children can be spared RT.