[Combination radiotherapy-immunotherapy in genitourinary cancer]. / Combinaison radiothérapie-immunothérapie en cancérologie génito-urinaire.

Immunotherapy occupies a growing place in urologic oncology, mainly for kidney and bladder cancers. On the basis of encouraging preclinical work, the combination of immunotherapy with radiotherapy aims to increase the tumor response, including in metastatic tumors, which raises many hopes, which this article reviews.

[Spinal anesthesia may diminish left ventricular function: a study by means of intraoperative transthoracic echocardiography]. / La anestesia subaracnoidea (espinal) podría disminuir la función ventricular izquierda: estudio con ecocardiografía transtorácica intraoperatoria.

BACKGROUND: Spinal anesthesia reduces arterial blood pressure mainly because of vasodilation secondary to blocking preganglionic fibers in the sympathetic nervous system. It is hypothesized, however, that spinal anesthesia may also be a direct cause of some degree of myocardial depression. These factors may be studied by means of transthoracic echocardiography to detect changes in left ventricular function following start of spinal anesthesia. MATERIAL AND METHODS: Left ventricular function was assessed in ASA 1 patients before spinal anesthesia, by means of measurements of left ventricular systolic and diastolic volumes, ejection fraction, the Doppler transmitral (E and A) and tissue (E', A', and Sm) inflow velocities, and the left ventricular outflow tract velocity. The measurements were repeated after the start of spinal anesthesia. RESULTS: Fifty-five patients (58% men; mean [SD] age, 46.9 [15.7] years) were studied. The spinal block caused a significant reduction in systolic and diastolic arterial blood pressures (P < .0009). Diastolic function also decreased (the E wave from 69.52 [11.24] to 61.59 [10.82] cm x s(-1) and the A wave from 50.18 [10.69] to 43.67 [13.75] cm x s(-1); P < .0001). Also reduced was the left ventricular outflow tract velocity, from 18.77 (4.89) to 15.64 (4.75) cm x s(-1) (P < .00001). There were no significant changes in systolic and diastolic volumes or ejection fraction. There was no correlation between the level of spinal block and the magnitude of changes. CONCLUSIONS: Left ventricular function was compromised after spinal anesthesia without significant changes in left ventricular volumes. We can infer that the reduction in arterial blood pressure after a spinal block might be due to some degree of direct ventricular depression.

La anestesia subaracnoidea (espinal) podría disminuir la función ventricular izquierda: Estudio con ecocardiografía transtorácica intraoperatoria / Spinal anesthesia may diminish left ventricular function: a study by means of intraoperative transthoracic echocardiography

INTRODUCCIÓN: La anestesia subaracnoidea (espinal)produce disminución de la presión arterial y su principalcausa sería la vasodilatación secundaria al bloqueo defibras preganglionares simpáticas. Se postula, sinembargo, que también podría producir algún grado dedepresión miocárdica directa. Para determinar estos factoresse pueden estudiar con ecocardiografía transtorácica(ETT) los cambios en la función del ventrículoizquierdo (VI) de una anestesia espinal.MATERIAL Y MÉTODOS: Se evaluó la función ventricular depacientes ASAI previa a la anestesia espinal. Se midió el volumensistólico del ventrículo izquierdo (VSFVI), volumen diastólico(VDFVI), fracción de eyección (FE), Doppler llenadotransmitral (E, A), Doppler tisular (E’, A’ y Sm) e integral develocidad del tracto de salida del VI (ITV). Este mismo examense repitió después de instaurarse la anestesia espinal.RESULTADOS: Se estudiaron 55 pacientes, 58% hombres,edad 46,9 ± 15,7 años. El bloqueo espinal produjouna disminución significativa de presión arterial sistólicay diastólica (p < 0,0009), de la función diastólica, dondela onda E disminuyó desde 69,52 ± 11,24 a 61,59 ±10,82 cm seg–1 y la onda A desde 50,18 ± 10,69 a 43,67 ±13,75 cm seg–1 (p < 0,0001) y de ITV desde 18,77 ± 4,89a 15,64 ± 4,75 cm seg–1 (p < 0,00001) sin cambios significativosen el VDF, VSF y FE. No existió correlación entreel nivel del bloqueo con la magnitud de estos cambios.CONCLUSIÓN: Los resultados demostraron que tras laanestesia espinal se comprometió la función ventricularizquierda, sin que cambiaran los volúmenes del VI enforma significativa. A partir de estos resultados puedeinferirse que la disminución de la presión arterial luegode un bloqueo espinal podría deberse también a algúngrado directo de depresión ventricular(AU)

BACKGROUND: Spinal anesthesia reduces arterialblood pressure mainly because of vasodilation secondaryto blocking preganglionic fibers in the sympatheticnervous system. It is hypothesized, however, that spinalanesthesia may also be a direct cause of some degree ofmyocardial depression. These factors may be studied bymeans of transthoracic echocardiography to detectchanges in left ventricular function following start ofspinal anesthesia.MATERIAL AND METHODS: Left ventricular functionwas assessed in ASA 1 patients before spinal anesthesia,by means of measurements of left ventricular systolicand diastolic volumes, ejection fraction, the Dopplertransmitral (E and A) and tissue (E', A', and Sm) inflowvelocities, and the left ventricular outflow tract velocity.The measurements were repeated after the start ofspinal anesthesia.RESULTS: Fifty-five patients (58% men; mean [SD]age, 46.9 [15.7] years) were studied. The spinal blockcaused a significant reduction in systolic and diastolicarterial blood pressures (P<.0009). Diastolic functionalso decreased (the E wave from 69.52 [11.24] to 61.59[10.82] cm·s–1 and the A wave from 50.18 [10.69] to 43.67[13.75] cm·s–1; P<.0001). Also reduced was the leftventricular outflow tract velocity, from 18.77 (4.89) to15.64 (4.75) cm·s–1 (P<.00001). There were no significantchanges in systolic and diastolic volumes or ejectionfraction. There was no correlation between the level ofspinal block and the magnitude of changes.CONCLUSIONS: Left ventricular function wascompromised after spinal anesthesia without significantchanges in left ventricular volumes. We can infer that thereduction in arterial blood pressure after a spinal blockmight be due to some degree of direct ventricular depression(AU)

[Echocardiography-derived Tei index during surgery, a predictor of postoperative cardiovascular complications]. / Indice ecocardiográfico de Tei durante cirugía no cardiaca como predictor de complicaciones cardiovasculares postoperatorias.

BACKGROUND AND OBJECTIVE: The Tei index is a Doppler echocardiographic parameter that reflects both systolic and diastolic myocardial function. Our aim was to monitor the Tei index by transesophageal echocardiography during noncardiac surgery to explore the correlation between this parameter and the incidence of postoperative cardiovascular complications. MATERIAL AND METHODS: Patients at risk of cardiovascular complications were enrolled. The Tei index was derived from the pattern of pulsed Doppler transmitral filling and aortic outflow, by dividing the sum of isovolumetric contraction and relaxation intervals by ejection time in milliseconds. RESULTS: Seventy-three patients (58% men) were enrolled. The mean (SD) age was 68 (12) years. Two groups were identified based on myocardial function. A Tei index over 0.35 defined group 2 (n = 25) and correlated with a larger number of postoperative cardiovascular events. In patients with a normal Tei index less than 0.35 (group 1, n = 48), the incidence of cardiovascular complications was lower. Hypotension occurred in 60% of patients in group 2 and 21% of those in group 1, hypertension in 24% of group 2 and 4.1% of group 1, and pulmonary edema in 8% of group 2 and 2.1% of group 1 (P < .05 for all comparisons). CONCLUSIONS: This pilot study found that patients with a high Tei index were more likely to develop postoperative cardiovascular complications. This index may provide a useful indicator to take into consideration in planning hemodynamic management when patients have a history of cardiovascular disease.

Índice ecocardiográfico de Tei durante cirugía no cardiaca comopredictor de complicaciones cardiovasculares postoperatorias / Echocardiography-derived Tei index during surgery, a predictor of postoperative cardiovascular complications

OBJETIVOS: El índice de función miocárdica (índice deTei) es un parámetro obtenido con ecocardiografíamediante Doppler, que estudia en forma conjunta e integradala sístole y la diástole. El objetivo del presenteestudio es evaluar si el índice de Tei medido con ecocardiografíatransesofágica (ETE) durante cirugía no cardiacase correlaciona con una mayor incidencia de eventoscardiovasculares postoperatorios.MATERIAL Y MÉTODOS: Se estudiaron pacientes conriesgo cardiovascular. El índice de Tei se midió con ETEdesde la curva de Doppler pulsado de llenado transmitraly de flujo aórtico, dividiendo la suma del tiempo decontracción y relajación isovolumétrica por el tiempo deeyección en milisegundos.RESULTADOS: Se incluyeron 73 pacientes, el 58% varones,con una edad promedio de 68 ± 12 años. Se determinódos grupos según el índice de función miocárdica. Uníndice de función miocárdica mayor de 0,35 (grupo 2, n= 25 pacientes) se correlacionó con un mayor número deeventos cardiovasculares postoperatorios. El grupo 1 (n= 48 pacientes) con índice de función miocárdica< 0,35 (normal) presentó una menor incidencia de eventos.Destacó la hipotensión en 60% de enfermos del grupo2 frente a 21% del grupo 1 (p < 0,05), hipertensión en24% de los casos del grupo 2 frente a 4,1% del grupo 1(p < 0,05) y congestión pulmonar 8% en el grupo 2 y2,1% del grupo 1 (p < 0,05).CONCLUSIONES: En este estudio preliminar se observóque pacientes con un índice de Tei patológico podríantener una mayor incidencia de complicaciones cardiovascularespostoperatorias. Este índice podría ser un factormás a considerar en el tratamiento hemodinámico depacientes con antecedentes de patología cardiovascular (AU)

BACKGROUND AND OBJECTIVE: The Tei index is aDoppler echocardiographic parameter that reflects bothsystolic and diastolic myocardial function. Our aim wasto monitor the Tei index by transesophagealechocardiography during noncardiac surgery to explorethe correlation between this parameter and theincidence of postoperative cardiovascular complications.MATERIAL AND METHODS: Patients at risk ofcardiovascular complications were enrolled. The Teiindex was derived from the pattern of pulsed Dopplertransmitral filling and aortic outflow, by dividing thesum of isovolumetric contraction and relaxationintervals by ejection time in milliseconds.RESULTS: Seventy-three patients (58% men) wereenrolled. The mean (SD) age was 68 (12) years. Twogroups were identified based on myocardial function. ATei index over 0.35 defined group 2 (n=25) andcorrelated with a larger number of postoperativecardiovascular events. In patients with a normal Teiindex less than 0.35 (group 1, n=48), the incidence ofcardiovascular complications was lower. Hypotensionoccurred in 60% of patients in group 2 and 21% of thosein group 1, hypertension in 24% of group 2 and 4.1% ofgroup 1, and pulmonary edema in 8% of group 2 and2.1% of group 1 (P<.05 for all comparisons).CONCLUSIONS: This pilot study found that patientswith a high Tei index were more likely to developpostoperative cardiovascular complications. This indexmay provide a useful indicator to take into considerationin planning hemodynamic management when patientshave a history of cardiovascular disease (AU)

[How to organize the emergency department of primary care hospitals in the future? Nyon's regional hospital experience]. / Quelle organisation pour les services d'urgence des hôpitaux périphériques de demain? L'exemple de l'hôpital de Nyon.

Optimization of patients flow can decrease the overcrowding of the emergency department (ED) and improve the level of patient's satisfaction. The prospective analysis of 502 consecutive admissions at the Nyon regional hospital's ED shows a mean length of stay (LOS) of 145 minutes, for a majority of low-severity cases admitted during working hours. A significant LOS variability reveals transient episodes of overcrowding, which lead to an increase in the LOS of mainly ambulatory patients. Our analysis shows that both the ED's structure and the medical organization create a gap between ED performance as care provider and the patients' expectations, and suggests that a separation of low-versus high-complexity cases is necessary. Patients' flow analysis can detect ED overcrowding and may help find the appropriate solutions to reduce it.

[Intraoperative transesophageal echocardiography and systolic anterior motion of the mitral valve: findings during noncardiac surgery]. / Ecocardiografía transesofágica intraoperatoria y movimiento sistólico anterior de válvula mitral: hallazgo intraoperatorio durante cirugía no cardíaca.

Systolic anterior motion is an under-recognized cause of acute systemic hypotension during noncardiac surgery. This dynamic event has come to light with the introduction of intraoperative transesophageal echocardiography, which provides anatomic and functional images in real time. The cause of this abnormal motion is still uncertain, although it is thought that changes in the shape and function of the left ventricle allow displacement of the mitral valve annulus so that 1 or more leaflets can be pulled toward the outflow tract and obstruct it during the systole. It is important to recognize and diagnose this phenomenon as a cause of hypotension during noncardiac surgery because it can be treated with volume replacement and beta-blockers. The results of such measures can be monitored on intraoperative echocardiographic images. Volume replacement should increase the size of the ventricle and the beta-blockers should decrease the hyperdynamic state. We report a case of abnormal systolic motion during noncardiac surgery that was managed with the help of echocardiography.

Ecocardiografía transesofágica intraoperatoria y movimiento sistólico anterior de válvula mitral: hallazgo intraoperatorio durante cirugía no cardíaca / Intraoperative transesophageal echocardiography and systolic anterior motion of the mitral valve: findings during noncardiac surgery

El fenómeno de movimiento sistólico anormal de la válvulamitral es una entidad clínica poco reconocida comocausa de hipotensión arterial sistémica aguda intraoperatoriadurante cirugía no cardíaca. Con el advenimiento dela ecocardiografía transesofágica intraoperatoria que permiteobtener imágenes anatómicas y funcionales cardíacasen tiempo real, este fenómeno dinámico se ha hecho evidente.Su etiología aunque poco clara, se piensa que sedebe a cambios morfológicos y funcionales del ventrículoizquierdo que permiten el desplazamiento del anillo valvularmitral lo que facilita que uno o ambos velos sean arrastradosdurante la sístole hacia el tracto de salida del ventrículoizquierdo, obstruyéndolo. La importancia que tienesu diagnóstico y reconocimiento como causa de hipotensióndurante el intraoperatorio de una cirugía no cardíacaes que su tratamiento se basa en el aporte de volumen y ala utilización preferente de betabloqueantes. La ecocardiografíaintraoperatoria permite la monitorización y visualizaciónde los resultados de esta terapia. Con el aporte devolumen aumenta el tamaño ventricular y con el uso debetabloqueantes se logra disminuir el estado hiperdinámico.Se presenta el siguiente caso clínico ocurrido duranteuna cirugía no cardíaca donde el manejo y la evolucióndependieron de las imágenes diagnósticas de movimientosistólico anormal realizadas con ecocardiografía

Systolic anterior motion is an under-recognized cause of acute systemic hypotension during noncardiac surgery. This dynamic event has come to light with the introduction of intraoperative transesophageal echocardiography, which provides anatomic and functional images in real time. The ;;cause of this abnormal motion is still uncertain, although it ;;is thought that changes in the shape and function of the left ;;ventricle allow displacement of the mitral valve annulus so ;;that 1 or more leaflets can be pulled toward the outflow ;;tract and obstruct it during the systole. It is important to ;;recognize and diagnose this phenomenon as a cause of ;;hypotension during noncardiac surgery because it can be ;;treated with volume replacement and Beta-blockers. The ;;results of such measures can be monitored on intraoperative ;;echocardiographic images. Volume replacement should ;;increase the size of the ventricle and the Beta-blockers should ;;decrease the hyperdynamic state. We report a case of ;;abnormal systolic motion during noncardiac surgery that ;;was managed with the help of echocardiography

Supuración crónica perianal por cuerpo extraño / Chronic perianal discharge caused by a foreign body

El empalamiento perineal es una lesión poco frecuente, que puede dar origen a un cuadro de supuración crónica perineal cuya etiología no es el habitual absceso o fístula perianal. Se presenta el caso de un paciente de 34 años que sufrió un empalamiento perineal en accidente laboral, presentando descarga purulenta perianal en forma casi permanente por cinco años. Durante su evolución se trató como una fístula, con fistulectomía parcial y ligadura elástica, sin remisión de la sintomatología. Se realizó fistulografía bajo TAC y colonoscopía con inyección de azul de metileno y agua oxigenada por el trayecto fistuloso, que no evidenciaron comunicación a recto, por lo que se decidió la exploración quirúrgica. Se extrajo un cuerpo extraño, correspondiente a tela, luego de lo cual se objetivó la cicatrización del orificio fistuloso a las dos semanas. El último control se realizó al mes de la cirugía.

Risk of melanoma following adulthood cancer: a case-control study.

Melanoma is a severe skin cancer related to sun exposure. Whether this malignancy is linked to exposure to ionising radiation during adulthood is still controversial. This case-control study examined the risk of melanoma following treatment for an adulthood first malignant neoplasm (FMN). Cases were patients who presented with cutaneous melanoma after a first cancer in adulthood. Controls (3 per case) were patients free of melanoma, matched for age, duration of follow-up since the FMN, type of FMN, and followed in the same institution. A total of 57 cases and 171 controls were included. In the final multivariate analysis, no risk of melanoma was associated with radiotherapy (odds ratio (OR) for 1 Gy = 1.01, 95% confidence interval (95%CI) 0.96-1.07) nor hormonotherapy, whereas chemotherapy use (OR = 2.3, 95%CI 0.93-5.6) and having a history of familial cancer (OR = 2.8, 95%CI 1.3-5.9) exhibited a nearly significant risk. In conclusion, unlike the evidence for risk of exposure to ionising radiation during childhood, we did not substantiate a risk for association of melanoma with exposure to ionising radiation during adulthood. The risk associated with chemotherapy should justify the implementation of skin surveillance for early detection of melanoma in these patients.

Eimeria tenella microneme protein EtMIC3: identification, localisation and role in host cell infection.

The gene coding for Eimeria tenella protein EtMIC3 was cloned by screening a sporozoite cDNA library with two independent monoclonal antibodies raised against the oocyst stage. The deduced sequence of EtMIC3 is 988 amino acids long. The protein presents seven repeats in tandem, with four highly conserved internal repeats and three more divergent external repeats. Each repeat is characterised by a tyrosine kinase phosphorylation site, WRCY, and a reminiscent motif of the thrombospondin1 (TSP1)-type I domain, CXXXCG. The protein EtMIC3 is localised at the apex of free parasite stages. It is not detected in the early intracellular parasite stage but is synthesised in mature schizonts. Secretion of the protein is induced when sporozoites are incubated in complete medium at 41 degrees C. Strangely enough, the two independent mAb that allow cloning of EtMIC3 interfere with parasitic growth in different ways. One is able to inhibit parasite invasion whereas the other inhibits development. Expression and localisation of the protein EtMIC3 are consistent with a protein involved in the invasion process as is expected for a microneme protein.

Radiation dose, chemotherapy, hormonal treatment and risk of second cancer after breast cancer treatment.

In total, 281 of the 7711 women who were initially treated for breast cancer between 1954 and 1983 at the Gustave Roussy Institute developed a second malignant neoplasm (SMN) other than second primary breast cancer and nonmelanoma skin cancer at least 1 year after breast cancer treatment. We carried out a nested case-control study to determine the overall relationship between the dose of radiotherapy received at a given anatomical site and the risk of SMN at the same site. In total, 75% of the cases of SMN were previously treated by radiotherapy, as compared to 73% of the controls. In the irradiated patients, the median local dose was higher among cases (3.1 Gy) than among controls (1.3 Gy). More than 40% of the irradiated patients received a local dose of less than 1 Gy. A purely quadratic relationship was observed between the dose of radiation received at an anatomical site and the risk of SMN at this site. According to the quadratic model, the excess risk of SMN was 0.2% (95% CI 0.05-0.5%) when the target organ received 1 Gy. This risk did not differ significantly according to age at the time of radiotherapy (<40 vs >or=40 years). The risk of SMN was 6.7-fold higher for doses of 25 Gy or more than in the absence of radiotherapy. No carcinogenic effect of chemotherapy was observed and a dose-effect relationship between the length of tamoxifen treatment and SMN occurrence was found. This relationship was limited to endometrial cancers and did not modify the relationship with radiation dose. Our results suggest that high radiation doses slightly increase the risk of second malignancies after breast cancer.

Differential localisation of an Eimeria tenella aspartyl proteinase during the infection process.

Aspartyl proteinases are essential for the survival of many pathogens. A single copy gene in species of Eimeria encodes an aspartyl proteinase, which we propose should be called eimepsin to conform to the commonly used names of this family of proteinases. An epitope map, constructed using BIAcore technology, confirmed the specificity of 14 mAbs for eimepsin and defined four antigenic domains, which were conserved between native and recombinant forms of eimepsin. In resting sporozoites, mAb defining antigenic domains I and II stained the refractile body organelles, whereas those defining antigenic domains III and IV stained cytoplasmic granules. During host cell invasion, the staining patterns of mAb defining antigenic domains I, III and IV changed dramatically with the apical tips of invading sporozoites becoming strongly stained. In contrast, mAb defining antigenic domain II continued to stain only the refractile bodies. During early schizogony, mAb to all four domains stained the single fused refractile body, but when schizonts matured, mAb to antigenic domains I, III and IV stained the apical tip of merozoites whereas those to antigenic domain II continued to follow the developmental redistribution of the refractile body. Irrespective of localisation, mAb to three antigenic domains recognised a polypeptide of 49 kDa, which from N-terminal sequencing corresponds to a mature form of eimepsin. Staining with fluorescent pepstatin localised a mature, active form of eimepsin to the refractile bodies of the sporozoite, schizont and first generation merozoite. It remains to be determined whether eimepsin has a catalytic function within the refractile body or whether the activated enzyme is stored in the refractile body so that it can be rapidly redistributed to the apical tip during parasite invasion.

Humeral fracture secondary to civilian gunshot injury.

Violence is the leading cause of death in the USA. The cost of violence due to gunshot wound is about $425 billion. While the closed fracture of the humerus is common, humeral shaft fractures caused by gunshot wound occur infrequently. There is much controversy regarding their management, i.e. should these injuries be treated surgically or can they be safely treated with minimal intervention. The aim of this study is to review our experience in the management of fourteen patients with a humeral fracture due to gunshot wounds. Of fourteen, seven patients were treated with local debridement, oral antibiotics and fracture brace. The remaining seven patients underwent surgical stabilization of the fracture. The time to union was similar in both groups (6 weeks in non-operative to 9 weeks in open treatment). In conclusion, fracture of the humeral shaft secondary to low velocity gunshot wound in the civilian setting can safely be treated as a closed fracture with local wound care and oral antibiotics.

Purification of first-generation Eimeria tenella schizonts.

A rapid and simple method for purifying first-generation Eimeria tenella schizonts was developed with infected chicken cecal tissue. The schizonts were harvested from the tissue by treatment with a mixture of 3 enzymes: hyaluronidase, dispase, and collagenase. Subsequent purification of the parasites by filtration through gauze and centrifugation resulted in a clean final preparation compared with the starting material. Microscopical and biochemical examinations, performed to assess the quality of the schizont purification, showed a high degree of purity. This procedure may be used to obtain clean schizonts minimally contaminated with host-cell debris in order to study this parasitic stage.

Eimeria tenella: cloning and characterization of cDNA encoding a S3a ribosomal protein.

A lambda Zap II cDNA library was constructed from Eimeria tenella first- generation schizonts mRNA and screened with a mouse serum raised against this parasitic stage. This serum identified a clone encoding a S3a ribosomal protein (EtS3a). The 858-bp cDNA fragment, containing the entire parasitic gene encoded a highly basic protein of 264 amino acids (aa) with a molecular weight of 29.780kDa. Based upon amino acid sequence comparison, EtS3a is highly homologous to v-fos transformation effector (encoded by the fte-1 gene) and cyc-07 (a plant homologue of fte-1) and similar to the yeast MFT1 (encoded by the mitochondrial fusion targeting gene). The expressions of mammalian fte-1, plant cyc-07 and yeast MFT1 have all been shown to be cell-cycle-regulated and involved in protein synthesis at the level of the ribosome. Since EtS3a expression is also developmentally regulated, we suggest that this gene product is a functional homologue of fte-1, cyc-07 and MFT1 and an important molecule regulating the development of Eimeria tenella.

Recombination of endogenous D2 dopamine receptor gene with a metallothionein promoter in GH4C1 cells confers functional and inducible D2 response.

We have previously shown that expression of a functional endogenous D2 short dopamine receptor is obtained in GH4C1 cells following transfection with a plasmid that confers resistance to neomycin (pRSVNeo) (Allard et al. (1993) Biochem. Biophys. Res. Commun. 193, 801-807). In order to better understand the mechanisms responsible for such a phenomenon, we cloned and sequenced the 5' region of the D2 gene present in native GH4C1 cells as well as the cDNA of transfected cells. No homology with the published sequence of the rat D2 dopamine receptor promoter was found; however, this region has perfect homology with the mouse metallothionein promoter. In cells expressing D2 receptor, the promoter is fully functional and can regulate dopaminergic D2 receptor mRNA levels and receptor expression in a dose-dependent manner in the presence of Zn2+ or Cd2+. The receptor level is raised from 500 to 3000 fmol/mg of protein in the presence of 100 microM of Zn2+. These results suggest that in GH4C1 cells, a recombination between the mouse metallothionein promoter and the D2 dopamine receptor took place. This system provides us with a cell line expressing an endogenous dopamine D2 receptor in which the level of expression can be easily modulated.

Identification of the nucleic acid binding domain of the rotavirus VP2 protein.

The bovine rotavirus VP2 protein is the major component of the core and forms the most internal layer surrounding the dsRNA genome. We have constructed recombinant baculoviruses expressing truncated VP2 proteins. The nucleic acid binding activity of these truncated proteins was tested by North-Western blotting experiments with single-stranded and double-stranded probes. The nucleic acid binding domain in VP2 was localized between amino acids 1 to 132. Recombinant proteins bound single-stranded and double-stranded nucleic acids, but showed less affinity for double-stranded RNA and DNA. Interactions of VP2 with the genome were investigated in viral single-shelled particles by u.v.-cross-linking. In these experiments, only VP2 protein bound the genomic RNA in purified single-shelled particles.