Mean glandular dose in the mammary gland and dose of radiation in the thyroid gland and lens in women with and without breast implants during different modalities of mammography.

There have always been concerns about the secondary effects of diagnostic methods that use ionizing radiation. During mammography, the parameters to be concerned about are the mean glandular dose and the scatter dose. We evaluated the dose of radiation to the breast, thyroid gland, and lens in digital mammography in women with and without implants, in tomosynthesis in women with and without implants, and in contrast-enhanced mammography. MATERIALS AND METHODS: The study included 212 women with and without disease who were attended at the Centro Clínico de Estereotaxia, CECLINES, in Caracas, Venezuela, between June 2017 and August 2017; the women were classified into five groups according to the mammographic modality used to evaluate them and whether or not they had implants. The statistical analysis included descriptive statistics for the study population. We used the Mann-Whitney U to compare the mean glandular dose and dose in the thyroid gland and lens between groups. RESULTS: The mean glandular dose and the dose of radiation received in the thyroid and lens were within the acceptable range. In a few exceptions, the mean glandular dose per view was slightly higher than 3 mGy. The scatter dose to the thyroid gland and the lens during mammography has a very small contribution to the annual dose equivalent. CONCLUSION: The mean glandular dose and the scatter dose to the thyroid gland and lens delivered during tomosynthesis and 2D mammography in women with implants were higher than those delivered during other mammographic techniques in women without implants.

Mean glandular dose in the mammary gland and dose of radiation in the thyroid gland and lens in women with and without breast implants during different modalities of mammography. / Dosis glandular promedio en glándula mamaria y dosis de radiación en glándula tiroides y cristalino en mujeres con y sin implantes mamarios durante diferentes modalidades mamográficas.

There have always been concerns about the secondary effects of diagnostic methods that use ionizing radiation. During mammography, the parameters to be concerned about are the mean glandular dose and the scatter dose. We evaluated the dose of radiation to the breast, thyroid gland, and lens in digital mammography in women with and without implants, in tomosynthesis in women with and without implants, and in contrast-enhanced mammography. MATERIALS AND METHODS: The study included 212 women with and without disease who were attended at the Centro Clínico de Estereotaxia, CECLINES, in Caracas, Venezuela, between June 2017 and August 2017; the women were classified into five groups according to the mammographic modality used to evaluate them and whether or not they had implants. The statistical analysis included descriptive statistics for the study population. We used the Mann-Whitney U to compare the mean glandular dose and dose in the thyroid gland and lens between groups. RESULTS: The mean glandular dose and the dose of radiation received in the thyroid and lens were within the acceptable range. In a few exceptions, the mean glandular dose per view was slightly higher than 3mGy. The scatter dose to the thyroid gland and the lens during mammography has a very small contribution to the annual dose equivalent. CONCLUSION: The mean glandular dose and the scatter dose to the thyroid gland and lens delivered during tomosynthesis and 2D mammography in women with implants were higher than those delivered during other mammographic techniques in women without implants.

Evaluation of functionality of type II toxin-antitoxin systems of Clostridioides difficile R20291.

Clostridioides difficile is a nosocomial, Gram-positive, strictly anaerobic, spore-forming pathogen capable of colonizing and proliferating in the human intestine. In bacteria, it has been shown that the Toxin-Antitoxin systems mediate the cellular response to external stress by initiating processes such as biofilm formation and programmed cell death. This work aims to evaluate the functionality of four type II TA modules of Clostridioides difficile R20291. We performed bioinformatic analysis to search for putative TA systems using the TADB platform. Then we performed a heterologous expression assay to evaluate the functionality of these systems. Our results showed that the MazEF and RelBE systems were functional, suggesting that their corresponding toxins possess an endoribonuclease activity. In conclusion, MazEF and RelBE systems of C. difficile R20291 are functional in a heterologous expression system.

Inhibitory effect of biofilm-forming Lactobacillus kunkeei strains against virulent Pseudomonas aeruginosa in vitro and in honeycomb moth (Galleria mellonella) infection model.

Biofilms correspond to complex communities of microorganisms embedded in an extracellular polymeric matrix. Biofilm lifestyle predominates in Pseudomonas aeruginosa, an opportunistic Gram negative pathogen responsible for a wide spectrum of infections in humans, plants and animals. In this context, anti-biofilm can be considered a key strategy to control P. aeruginosa infections, thereby more research in the field is required. On the other hand, Lactobacillus species have been described as beneficial due to their anti-biofilm properties and their consequent effect against a wide spectrum of pathogens. In fact, biofilm-forming Lactobacilli seem to be more efficient than their planktonic counterpart to antagonise pathogenic bacteria. In this work, we demonstrated that Lactobacillus kunkeei, a novel Lactobacillus species isolated from honeybee guts, can form biofilms in vitro. In addition, the L. kunkeei biofilm can, in turn, inhibit the formation of P. aeruginosa biofilms. Finally, we found that L. kunkeei strains attenuate infection of P. aeruginosa in the Galleria mellonella model, presumably by affecting P. aeruginosa biofilm formation and/or their stability. Since L. kunkeei presents characteristics of a probiotic, this work provides evidence arguing that the use of this Lactobacillus species in both animals (including insects) and humans could contribute to impair P. aeruginosa biofilm formation.

Salmonella Typhimurium exhibits fluoroquinolone resistance mediated by the accumulation of the antioxidant molecule H2S in a CysK-dependent manner.

OBJECTIVES: To evaluate the contribution of cysK and cysM to the fluoroquinolone (ofloxacin) antibiotic resistance in Salmonella Typhimurium, and their impact on H2S and cysteine production through targeted mutagenesis. METHODS: Salmonella Typhimurium 14028s and its cysK and cysM mutants were tested for their susceptibility to ofloxacin, as determined by a broth microdilution test (to determine the MIC) and survival curves. H2S levels were measured by the Pb(AC)2 method and cysteine levels were determined using 5,5-dithio-bis-2-nitrobenzoic acid. DNA damage induced by antibiotic treatment was determined by PFGE. Finally, expression of cysK and cysM genes under antibiotic treatment was determined by real-time reverse transcription PCR. RESULTS: As determined by MIC, the ΔcysK strain was more resistant to ofloxacin, a reactive oxygen species (ROS)-producing fluoroquinolone, than the WT and ΔcysM strains, which correlates with survival curves. Moreover, the ΔcysK strain exhibited higher H2S levels and lower cysteine levels than the WT strain. Finally, the ΔcysK strain exhibited lower DNA damage upon challenge with ofloxacin than the WT and ΔcysM strains. These results are in accordance with lower expression of cysK under ofloxacin treatment in the WT strain. CONCLUSIONS: This work demonstrated that cysteine metabolism in Salmonella Typhimurium modulated H2S levels, conferring resistance to second-generation fluoroquinolones.

Lose to win: marT pseudogenization in Salmonella enterica serovar Typhi contributed to the surV-dependent survival to H2O2, and inside human macrophage-like cells.

The difference in host range between Salmonella enterica serovar Typhimurium (S. Typhimurium) and Salmonella enterica serovar Typhi (S. Typhi) can be partially attributed to the gain of functions, to the loss of functions (i.e. pseudogenization), or to a combination of both processes. As previously reported, the loss of functions by pseudogenization may play a role in bacterial evolution, especially in host-restricted pathogens such as S. Typhi. The marT-fidL operon, located at the SPI-3, encodes the MarT transcriptional regulator and a hypothetical protein (i.e. FidL) with no significant similarities to known proteins, respectively. Even though predicted S. Typhimurium FidL exhibit 99.4% identity with S. Typhi FidL, marT has been annotated as a pseudogene in S. Typhi. In this work, we found that S. Typhi expressing S. Typhimurium marT-fidL exhibited an increased accumulation of reactive oxygen species (ROS), leading to a decreased survival in presence of H2O2. Moreover, we found that that the presence of a functional copy of S. Typhimurium marT-fidL in S. Typhi resulted in a repression of surV (STY4039), an ORF found in the S. Typhi SPI-3 but absent from S. Typhimurium SPI-3, that contribute to the resistance to H2O2 by decreasing the accumulation of ROS. Finally, we observed that the presence of S. Typhimurium marT-fidL in S. Typhi negatively affected the survival inside macrophage-like cells, but not in epithelial cells, after 24h post infection. Therefore, this work provides evidence arguing that marT pseudogenization in Salmonella Typhi contributed to the surV-dependent survival against H2O2, and inside human macrophage-like cells. This is a good example of how the loss of functions (marT pseudogenization) and the gain of functions (presence of surV) might contribute to phenotypic changes improving virulence.

Pseudogenization of sopA and sopE2 is functionally linked and contributes to virulence of Salmonella enterica serovar Typhi.

The difference in host range between Salmonella enterica serovar Typhimurium (S. Typhimurium) and S. enterica serovar Typhi (S. Typhi) can be partially attributed to pseudogenes. Pseudogenes are genomic segments homologous to functional genes that do not encode functional products due to the presence of genetic defects. S. Typhi lacks several protein effectors implicated in invasion or other important processes necessary for full virulence of S. Typhimurium. SopA and SopE2, effectors that have been lost by pseudogenization in S. Typhi, correspond to an ubiquitin ligase involved in cytokine production by infected cells, and to a guanine exchange factor necessary for invasion of epithelial cells, respectively. We hypothesized that sopA and/or sopE pseudogenization contributed to the virulence of S. Typhi. In this work, we found that S. Typhi expressing S. Typhimurium sopE2 exhibited a decreased invasion in different epithelial cell lines compared with S. Typhi WT. S. Typhimurium sopA completely abolished the hypo-invasive phenotype observed in S. Typhi expressing S. Typhimurium sopE2, suggesting that functional SopA and SopE2 participate concertedly in the invasion process. Finally, the expression of S. Typhimurium sopA and/or sopE2 in S. Typhi, determined changes in the secretion of IL-8 and IL-18 in infected epithelial cells.

Mortalidad prematura cardiovascular y sus costes: 20 años de seguimiento del estudio DRECE / Costs resulting from premature mortality due to cardiovascular causes: a 20-year follow-up of the DRECE study

Objetivos. Las enfermedades cardiovasculares permanecen todavía como la principal causa de muerte en España. El estudio Dieta y Riesgo de Enfermedades Cardiovasculares en España (DRECE) se basa en una cohorte representativa de la población general española en la que se analizan los hábitos nutricionales y de vida estudiando su asociación con los patrones de morbimortalidad. Hemos estimado el impacto, en términos de pérdida de productividad, de la mortalidad prematura atribuida a las enfermedades cardiovasculares. Métodos. La pérdida de productividad atribuida a mortalidad prematura se calculó desde 1991, basándose en los años de vida y de vida laboral potencialmente perdidos. Resultados. Durante el seguimiento de 20años de una cohorte de 4.779 sujetos se produjeron 225 fallecimientos (hombres, 152). El 16% de las defunciones se atribuyó a enfermedades cardiovasculares. Los costes por pérdidas de productividad por mortalidad prematura superaron los 29 millones de euros. De ellos, 4 millones de euros (14% del coste total) se debieron a causas cardiovasculares. Conclusiones. La mortalidad prematura cardiovascular en la cohorte DRECE ha supuesto un importante coste social por pérdidas de productividad laboral (AU)

Objectives. Cardiovascular diseases are still the leading cause of death in Spain. The DRECE study (Diet and Cardiovascular Disease Risk in Spain), based on a representative cohort of the Spanish general population, analyzed nutritional habits and lifestyle and their association with morbidity and mortality patterns. We estimated the impact, in terms of loss of productivity, of premature mortality attributed to cardiovascular diseases. Methods. The loss of productivity attributed to premature mortality was calculated from 1991, based on the potential years of life lost and the potential years of working life lost. Results. During the 20-year follow-up of a cohort of 4779 patients, 225 of these patients died (men, 152). Sixteen percent of the deaths were attributed to cardiovascular disease. The costs due to lost productivity by premature mortality exceeded 29 million euros. Of these, 4 million euros (14% of the total cost) were due to cardiovascular causes. Conclusions. Premature cardiovascular mortality in the DRECE cohort represented a significant social cost due to lost productivity (AU)

Costs resulting from premature mortality due to cardiovascular causes: A 20-year follow-up of the DRECE study. / Mortalidad prematura cardiovascular y sus costes: 20 años de seguimiento del estudio DRECE.

OBJECTIVES: Cardiovascular diseases are still the leading cause of death in Spain. The DRECE study (Diet and Cardiovascular Disease Risk in Spain), based on a representative cohort of the Spanish general population, analyzed nutritional habits and lifestyle and their association with morbidity and mortality patterns. We estimated the impact, in terms of loss of productivity, of premature mortality attributed to cardiovascular diseases. METHODS: The loss of productivity attributed to premature mortality was calculated from 1991, based on the potential years of life lost and the potential years of working life lost. RESULTS: During the 20-year follow-up of a cohort of 4779 patients, 225 of these patients died (men, 152). Sixteen percent of the deaths were attributed to cardiovascular disease. The costs due to lost productivity by premature mortality exceeded 29 million euros. Of these, 4 million euros (14% of the total cost) were due to cardiovascular causes. CONCLUSIONS: Premature cardiovascular mortality in the DRECE cohort represented a significant social cost due to lost productivity.

Salmonella Typhi shdA: pseudogene or allelic variant?

ShdA from Salmonella Typhimurium (ShdASTm) is a large outer membrane protein that specifically recognizes and binds to fibronectin. ShdASTm is involved in the colonization of the cecum and the Peyer's patches of terminal ileum in mice. On the other hand, shdA gene from Salmonella Typhi (shdASTy) has been considered a pseudogene (i.e. a nonfunctional sequence of genomic DNA) due to the presence of deletions and mutations that gave rise to premature stop codons. In this work we show that, despite the deletions and mutations, shdASTy is fully functional. S. Typhi ΔshdA mutants presented an impaired adherence and invasion of HEp-2 pre-treated with TGF-ß1, an inducer of fibronectin production. Moreover, shdA from S. Typhi and S. Typhimurium seem to be equivalent since shdASTm restored the adherence and invasion of S. Typhi ΔshdA mutant to wild type levels. In addition, anti-FLAG mAbs interfered with the adherence and invasion of the S. Typhi shdA-3xFLAG strain. Finally, shdASTy encodes a detectable protein when heterologously expressed in Escherichia coli DH5α. The data presented here show that shdASTy is not a pseudogene, but a different functional allele compared with shdASTm.

Escápula alada, ¿una entidad del área quirúrgica? / Winged scapula, a condition for the surgical area?

La escápula alada secundaria a la lesión del nervio torácico largo es una entidad poco frecuente. La etiología más frecuente relatada en la bibliografía está relacionada con actividades en el área quirúrgica, ya sea por malposicionamiento durante la anestesia-cirugía, ya sea por un evento traumático iatrogénico durante los procedimientos quirúrgicos. Exponemos 3 casos clínicos junto con una breve revisión etiológica y bibliográfica, para revisar las múltiples etiologías de dicha lesión y así no atribuirla siempre a dicha área de actuación, ya que estos no son los únicos causantes de la misma (AU)

The winged scapula secondary to long thoracic nerve injury is an uncommon condition. It is most frequently reported in the literature associated with surgical activities, either due to poor positioning during anesthesia or by an iatrogenic traumatic event during surgical procedures. We expose 3 cases and a brief etiological and literature review, to present the multiple origins of this injury, which are not always related to this area of activity, as these are not the only causes of this injury (AU)

Programa de rehabilitación de pacientes sometidos a trasplante de progenitores hematopoyéticos / Rehabilitation program of patients who have undergone hematopoietic stem cell transplantation

Introducción. La recuperación de la capacidad funcional es un objetivo terapéutico primordial, proponiéndose el ejercicio como terapia coadyuvante, para combatir los efectos del decondicionamiento físico tras el trasplante de células precursoras hematopoyéticas (TPH). Presentamos nuestro estudio con el fin de exponer nuestra experiencia con el protocolo usado en nuestra unidad dentro del enfoque integral de los pacientes sometidos a TPH. Material y métodos. Estudio descriptivo prospectivo, incluyendo a todos aquellos pacientes sometidos a TPH, en el periodo comprendido entre enero de 2011 y julio de 2012, admitidos en el protocolo realizado en nuestro servicio. Revisamos y recopilamos los datos epidemiológicos, demográficos, características de su enfermedad, grado de actividad física y funcionalidad, en un total de 50 casos registrados en nuestra base de datos. Resultados. Edad media de 48,94 años (10-66). Síndrome mielodisplásico como causa más frecuente (30,4%). Todos los pacientes sometidos a trasplante presentaron una pérdida de fuerza, medida por un descenso global medio en el balance muscular de un punto; mientras solo el 24% precisaron tratamiento rehabilitador específico, porque presentaban signos de fragilidad funcional. Todos ellos recibieron recomendaciones respecto a la actividad física y normas higienicodietéticas. La distancia capaz de recorrer se vio considerablemente disminuida, con un 45% únicamente capaz de caminar 0-500 m, frente a un 60% capaz de caminar más de 2 km pretrasplante. No se objetivó aumento de fatiga postrasplante. Conclusiones. Todos los pacientes sometidos a TPH deben participar en un programa de rehabilitación, para prevenir las consecuencias de la inmovilidad y efectos adversos del tratamiento oncohematológico(AU)

Introduction. Recovering functional capacity is a fundamental therapeutic target. Exercise is proposed as an adjuvant therapy to combat the effects of loss of physical conditioning after Hematopoietic Stem Cell Transplantation (HSCT). We present our study in order to describe our experience with the protocol having a comprehensive approach to patients subjected to HSCT which is currently being used in our unit. Material and methods. A descriptive prospective study including all patients who had undergone HSCT, admitted in the protocol from January 2011 to July 2012, was carried out. The epidemiologic and demographic data as well as characteristics of the condition, physical activity level and functionality from 50 cases recorded in the database of our unit were collected and reviewed. Results. Mean age of the sample was 48.94 years (10-66). Myelodysplastic syndrome was the most common cause (30.4%). All patients who underwent transplant showed a loss of strength, measured by a mean global decrease of 1 point in muscle balance, although only 24% required specific rehabilitation treatment due to signs of functional frailty. All of them received recommendations regarding physical activity and hygiene and diet guidelines. The distance the subjects could cover decreased considerably, 45% only being able to walk approximately 0-500 m, while 60% had been able to walk more than 2 km prior to the transplant stage. No increase in fatigue was observed after the transplant. Conclusions. All patients who undergo HSCT should participate in a physical exercise program to prevent the effects of the lack of mobility and the adverse effects of the oncological and hematological treatment(AU)

[Winged scapula, a condition for the surgical area?]. / Escápula alada, ¿una entidad del área quirúrgica?

The winged scapula secondary to long thoracic nerve injury is an uncommon condition. It is most frequently reported in the literature associated with surgical activities, either due to poor positioning during anesthesia or by an iatrogenic traumatic event during surgical procedures. We expose 3 cases and a brief etiological and literature review, to present the multiple origins of this injury, which are not always related to this area of activity, as these are not the only causes of this injury.

[Evaluation of the research performed in Spanish hospitals]. / Valoración de la investigación que se realiza en los hospitales españoles.

OBJECTIVES: No study that analyzes how the investigators who work in the Spanish hospitals perceived and evaluate the current research system has been performed. This work, carried out by the Scientific Forum of the Lilly Foundation, aims to improve the level of information on the research activity performed in the hospitals. SUBJECTS AND METHODS: By means of a «self-administered¼ interview made up of 34 items and aimed at physicians and other research professionals who work in the Spanish hospitals (272 surveyed), 3 questions were analyzed: a) general situation of biomedical research in Spain; b) administration of available resources: need for better resources, and c) evaluation and giving priority to biomedical research. RESULTS: The use of the data has shown strengths in the system such as the initiatives to promote research through contracts with FIS and post-residency (7.6/10 points); the beneficial effects of research and care quality (7.3/10); or support of the pharmaceutical industry through the sponsoring of clinical trials (6.9/10). However, it has also shown that there are some weaknesses in the organization of the centers, as for example, those referring to the differentiated allocation of the care cost of the research activity (5.1/10); to the coordination between them and the health care centers (2.8/10); to the integration and organization among care, teaching and research (3.6/10); and to decide the priorities (5.2/10) and evaluation (5.2/10) of the research activities. Furthermore, the value of the research as a fundamental activity of the hospitals is emphasized (4.7/10). CONCLUSIONS: The investigators surveyed consider that biomedical research in recent decades in the hospital setting has significantly improved and has had a positive effect in the number of publications. The subjects surveyed consider that research should have greater institutional support and recognition, and a more translational orientation, which would be translated into better quality of life of the citizens and registry of patents.

La medicina, una ciencia y un arte humanos / Medicine, a human science and art

No disponible

Analysis of the -1438 G/A polymorphism of the 5-HT2A serotonin receptor gene in bulimia nervosa patients with or without a history of anorexia nervosa.

A single nucleotide polymorphism (-1438 G/A) located 1438 base pairs upstream of the consensus start site of the 5-HT2A receptor gene has been reported. The hypothesis that this gene polymorphism may be a susceptibility factor in bulimia nervosa was explored in a female population of purgative bulimics. Bulimia nervosa patients who have suffered preceding anorexia nervosa episodes formed the so-called previous anorexia nervosa bulimic patient group. At variance with some previous reports, when the frequency distribution of genotypes and alleles was compared in patients and controls, no differences were detected regardless of whether the bulimia nervosa patients had suffered prior anorexia nervosa episodes.

Mango seed uses: thermal behaviour of mango seed almond fat and its mixtures with cocoa butter.

This paper deals with the physicochemical characterization, including thermal behaviour, by differential scanning calorimetry of mango seed almond fat (MAF), alone and in mixtures with cocoa butter (CB). Results showed that mango almond seeds contain about 5.28-11.26% (dw) of fat. The refraction index is 1.466, the saponification index 189.0 and the iodine index 41.76. Fatty acids found in MAF are oleic, stearic, and palmitic acids (40.81%, 39.07% and 9.29% (w/w), respectively) as well as smaller amounts of linoleic, with arachidic, behenic, lignoceric, and linolenic acids, among others. Calorimetric analysis showed that MAF crystallizes between 14.6 and -24.27 degrees C with a DeltaHc of 56.06 J/g and melts between -17.1 and 53.8 degrees C, with fusion maxima at 18.54 degrees C and 40.0 degrees C for the alpha and beta polymorphic forms. Their fusion enthalpies are 70.12 and 115.7 J/g. The MAF solids content profile is very similar to that of CB, both in stabilized and non-stabilized samples. The mixing compatibility was analyzed using isosolids curves of mixtures of different compositions.

Polymorphisms within the promoter and the intron 2 of the serotonin transporter gene in a population of bulimic patients.

The serotonin transporter (5-HTT) gene is a firm candidate to explain eating disorders. In this association study, two different polymorphisms were analysed: a variable number of tandem repeat (VNTR) polymorphism in intron 2 and a deletion/insertion polymorphism (5-HTTLPR) in the promoter region. The hypothesis that these gene polymorphisms may be a susceptibility factor in bulimia nervosa (BN) was explored in a female population of 102 purgative bulimics. BN patients who have suffered preceding anorexia nervosa (AN) episodes formed the so-called previous AN bulimic patient group. In our sample of normal-eater controls and purging type bulimics, regardless of whether or not the BN patients had suffered prior AN episodes, no differences were found considering the frequencies of genotypes, alleles or haplotypes of both polymorphic regions of the 5-HTT gene.

Sonographically guided directional vacuum-assisted breast biopsy: preliminary experience in Venezuela.

OBJECTIVE: The purpose of this study was to evaluate the use of sonographically guided directional vacuum-assisted biopsy in the histologic diagnosis of breast lesions. MATERIALS AND METHODS: Eighty-eight lesions in 83 women underwent sonographically guided 11-gauge directional vacuum-assisted breast biopsy during a 26-month period. Biopsies were performed using high-resolution sonography equipment with a 7.5-MHz transducer, obtaining a median of 17 specimens per lesion. Imaging studies, medical records, and histologic findings were reviewed. RESULTS: Median patient age was 48 years (range, 25-78 years). Median lesion size was 1.2 cm (range, 0.4-2.5 cm). Twenty-four (27.3%) of 88 lesions were palpable. The median time required to perform biopsy was 17 min (range, 10-40 min). Complete removal of the lesion seen at sonography occurred in 78 (88.6%) of 88 lesions and was significantly more frequent in lesions measuring 1.5 cm or less than in larger lesions (68/71 = 95.8% vs 10/17 = 58.8%,p < 0.0003). A surgical procedure was spared in 79 (95.2%) of 83 women. In 36 lesions with imaging and clinical follow-up after sonographically guided biopsy with benign findings (range, 4-24 months; median, 11.3 months), we found no evidence of cancer or scarring in the breast. CONCLUSION: In our small series, sonographically guided directional vacuum-assisted biopsy was a fast and accurate method for breast diagnosis. This technique resulted in complete removal of 95.8% of lesions shown at sonography measuring 1.5 cm or less and spared a surgical procedure in 95.2% of women. Further work is necessary to refine indications, evaluate cost-effectiveness, and assess long-term outcome.

Role of gonadal steroids in the corticotropin-releasing hormone and proopiomelanocortin gene expression response to Delta(9)-tetrahydrocannabinol in the hypothalamus of the rat.

Chronic exposure to Delta(9)-tetrahydrocannabinol (Delta(9)-THC) increases corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) gene expression in the rat hypothalamus. The levels of circulating gonadal steroids concurrently modulate both neuropeptides in male and female rats. However, it remains unknown whether gonadal steroids regulate Delta(9)-THC effects on CRH and POMC gene expression in the hypothalamus of male and female rats. To explore this hypothesis, experiments were conducted on intact, 2-week-gonadectomized, 1-week-gonadectomized, 1-week-dihydrotestosterone (DHT)- or estradiol-replaced male and female rats. One week after hormonal replacement, animals were treated with vehicle or Delta(9)-THC (5 mg/kg/day, i.p. for 7 days). Administration of Delta(9)-THC to intact male rats increased CRH gene expression. Castration abolished Delta(9)-THC effects of CRH gene expression in males but not in females. On the other hand, POMC mRNA levels were reduced as a result of castration, and DHT treatment did not prevent this decrease. Delta(9)-THC treatment similarly increases POMC gene expression of intact, orchidectomized and DHT-replaced males. In females, ovariectomy decreased CRH gene expression. Delta(9)-THC administration increased CRH gene expression to the same extent in castrated and estradiol-replaced rats. On the other hand, POMC gene expression was increased by ovariectomy, and Delta(9)-THC administration did only increase POMC transcript levels in the estradiol-replaced group. These data show that gonadal steroids differentially regulate the effects of Delta(9)-THC on both CRH and POMC gene expression in the hypothalamus of male and female rats, suggesting gender differences in the reaction to cannabinoids.