Design of a Bacillus thuringiensis-based formulation that increases feeding preference on Spodoptera exigua (Lepidoptera: Noctuidae) larvae.

A Bacillus thuringiensis (Bt)-based formulation intended to increase feeding response in Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) was developed. Eight matrices were prepared from natural ingredients and confronted with fresh maize leaves to select one highly palatable to larvae. The selected matrix was combined with Bt HD-125 strain at three different concentrations (30, 70, and 100 g/kg) of the spore-crystal complex to elaborate three insecticidal formulations. Effects caused by the matrix, including palatability, any adverse effect, and reduction in toxic activity of the strain, were tested on the formulations. Results indicated that the blend of modified cornstarch, porcine gelatin, and dried corncob was the most preferred by larvae. Formulations obtained were evaluated in mortality bioassays with neonate larvae in laboratory, using artificial diet, and in the greenhouse, with maize, Zea mays L., plants to compare their effectiveness when applied to natural food. In laboratory tests, all formulations, including a commercial formulation, were ingested by larvae causing high mortality in neonate larvae; in the greenhouse tests, formulations were also ingested causing mortality in larvae, overcoming commercial formulation effectiveness. Results suggest that the selected matrix combined with Bt 70 g/kg is the most suitable formulation to achieve effective control because this concentration acts faster than the lower concentration and is equal than the higher concentration. This formulation, designed specifically against a particular pest, is highly effective and offers a high potential for effective pest control.

Redefining the role of doxorubicin for the treatment of children with hepatoblastoma.

PURPOSE: Systemic chemotherapy has improved the survival of patients with hepatoblastoma (HB). INT-0098 Intergroup Liver Tumor Study demonstrated that patients with HB treated with either cisplatin/fluorouracil/vincristine (CFV) or cisplatin/doxorubicin (CD) had a similar survival. The Children's Oncology Group adopted the less toxic CFV as the standard regimen for treating HB. However, international cooperative groups still favor the CD combination. We therefore decided to revisit the role of doxorubicin for the treatment of HB. METHODS: Outcomes of patients with HB on the INT-0098 study were reviewed with an emphasis on the postevent survival time for both regimens to elucidate the role of doxorubicin in their retrieval. RESULTS: Sixty-four of the 173 randomly assigned patients had an event. Of these, 55 experienced progression or recurrence after initial treatment. Eleven (31%) of 36 patients treated with CFV were successfully retrieved with a doxorubicin-containing regimen and surgery and remain alive at last contact, whereas only one (6%) of 18 patients treated with CD was alive after retrieval therapy. CONCLUSION: CFV is effective for stage I or II HB. Doxorubicin can be omitted as part of initial therapy in the majority of these patients, potentially limiting the long-term cardiac toxicities, without compromising outcome. Doxorubicin is effective in rescuing patients with recurrent disease after CFV and should be incorporated as a means of intensifying initial therapy for advanced-stage, nonmetastatic HB. Outcome of patients with metastatic disease at diagnosis is poor, and improving their survival will require new therapeutic approaches.

Fibrolamellar hepatocellular carcinoma in children and adolescents.

BACKGROUND: Children with hepatocellular carcinoma (HCC) were treated on a prospective, randomized trial and were then analyzed to determine whether children with the fibrolamellar (FL) histologic variant of HCC have a more favorable presentation, increased surgical resectability, greater response to therapy, and improved outcome compared with children who have typical HCC. METHODS: Forty-six patients were enrolled on Pediatric Intergroup Hepatoma Protocol INT-0098 (Pediatric Oncology Group Study 8945/Children's Cancer Group Study 8881) between August 1989 and December 1992. After undergoing initial surgery or biopsy, children with Stage I HCC (n = 8 patients), Stage III HCC (n = 25 patients), and Stage IV HCC (n = 13 patients) were assigned randomly, regardless of histology, to receive treatment either with cisplatin, vincristine, and fluorouracil (n = 20 patients) or with cisplatin and continuous-infusion doxorubicin (n = 26 patients). RESULTS: Ten of 46 patients (22%) had the fibrolamellar variant of HCC (FL-HCC). For the entire cohort, the estimated 5-year event free survival (EFS) rate (+/- standard deviation) was 17% +/- 6%. There was no difference in outcome among patients who were treated with either regimen. The 5-year EFS rate for patients with FL-HCC was no different the rate for patients with typical HCC (30% +/- 15% vs. 14% +/- 6%, respectively; P = 0.18), although the median survival was longer in patients with FL-HCC. There was no difference in the number of patients with advanced-stage disease, the incidence of surgical resectability at diagnosis, or the response to treatment between patients with FL-HCC and patients with typical HCC. CONCLUSIONS: Children with FL-HCC do not have a favorable prognosis and do not respond any differently to current therapeutic regimens than patients with typical HCC. Children with initially resectable HCC have a good prognosis irrespective of histologic subtype, whereas outcomes are poor uniformly for children with advanced-stage disease. The use of novel chemotherapeutic agents and the incorporation of other treatment modalities are indicated to improve the dismal survival of pediatric patients with all histologic variants of advanced-stage HCC.

Hepatocellular carcinoma in children and adolescents: results from the Pediatric Oncology Group and the Children's Cancer Group intergroup study.

PURPOSE: To determine surgical resectability, event-free survival (EFS), and toxicity in children with hepatocellular carcinoma (HCC) randomized to treatment with either cisplatin (CDDP), vincristine, and fluorouracil (regimen A) or CDDP and continuous-infusion doxorubicin (regimen B). PATIENTS AND METHODS: Forty-six patients were enrolled onto Pediatric Intergroup Hepatoma Protocol INT-0098 (Pediatric Oncology Group (POG) 8945/Children's Cancer Group (CCG) 8881). After initial surgery or biopsy, children with stage I (n = 8), stage III (n = 25), and stage IV (n = 13) HCC were randomly assigned to receive regimen A (n = 20) or regimen B (n = 26). RESULTS: For the entire cohort, the 5-year EFS estimate was 19% (SD = 6%). Patients with stage I, III, and IV had 5-year EFS estimates of 88% (SD = 12%), 8% (SD = 5%), and 0%, respectively. Five-year EFS estimates were 20% (SD = 9%) and 19% (SD = 8%) for patients on regimens A and B, respectively (P =.78), with a relative risk of 1.2 (95% confidence interval, 0.60 to 2.3) for regimen B when compared with regimen A. Outcome was similar for either regimen within disease stages. Events occurred before postinduction surgery I in 18 (47%) of 38 patients with stage III or IV disease, and tumor resection was possible in two (10%) of the remaining 20 children with advanced-stage disease after chemotherapy. CONCLUSION: Children with initially resectable HCC have a good prognosis and may benefit from the use of adjuvant chemotherapy. Outcome was uniformly poor for children with advanced-stage disease treated with either regimen. New therapeutic strategies are needed for the treatment of advanced-stage pediatric HCC.

Treatment of children and adolescents with localized parameningeal sarcoma: experience of the Intergroup Rhabdomyosarcoma Study Group protocols IRS-II through -IV, 1978-1997.

BACKGROUND: We reviewed 611 patients with parameningeal sarcoma entered on Intergroup Rhabdomyosarcoma Study Group (IRSG) Protocols-II through IV (1978-1997), to delineate treatment results and evaluate prognostic factors. PROCEDURE: Primary sites were the middle ear/mastoid (N = 138), nasopharynx/nasal cavity (N = 235), paranasal sinuses (N = 132), parapharyngeal region (N = 29), and the pterygopalatine/infratemporal fossa (N = 77). Treatment was initial biopsy or surgery followed by multiagent chemotherapy and radiation therapy (XRT). Beginning in 1977, patients with cranial nerve palsy, cranial base bony erosion, and/or intracranial extension at diagnosis were considered as having meningeal involvement. They received triple intrathecal medications, whole brain XRT, and then spinal XRT. These treatments were successively eliminated from 1980 to 1991. RESULTS: The 611 patients' overall survival rate at 5 years was 73% (95% confidence interval, 70-77%). Favorable prognostic factors were: age 1-9 years at diagnosis; primary tumor in the nasopharynx/nasal cavity, middle ear/mastoid, or parapharyngeal areas; no meningeal involvement; and non-invasive tumors (T1). Thirty-five of 526 patients (6.7%) with information about presence/absence of meningeal involvement at diagnosis developed central nervous system (CNS) extension at 5-164 weeks (median, 46 weeks) after starting therapy. The estimated 5-year cumulative incidence rate of CNS extension during the study period was 5-7% (P = 0.88). CONCLUSIONS: Biopsy, XRT to the target volume, and systemic chemotherapy are successful treatments for the large majority of patients with localized parameningeal sarcoma. Carefully defining and irradiating the initial volume should reduce the risk of CNS failure. Aggressive initial surgical management of these patients is unnecessary.

Actividad estral de perras callejeras en la ciudad de Mérida, Yucatán y su relación con edad, tamaño y condición corporal / Oestral activity of stray bitches in the city of Mérida and its relation with age, size and corporal condition

Introducción. Los perros callejeros representan un riesgo para la salud humana por las enfermedades zoonóticas que se presentan en esta especie. La alta fertilidad y gran prolificidad de esta especie incrementa más el problema del perro callejero, sobre todo si no existen campañas efectivas que controlen su población. En la estacionalidad reproductiva que es la de mayor actividad estral, se agrupan los perros callejeros para aparearse y es cuando las campañas de control pueden ser más eficaces. En este estudio se determinó la actividad estral de la perra callejera en la ciudad de Mérida, Yucatán, México durante un año y se evaluó la relación de la edad, tamaño y condición corporal de las perras con la aparición de estros. Material y métodos. Se tomaron muestras mensuales mediante hisopos de la mucosa vaginal de un total de 114 perras callejeras en la perrera municipal de la ciudad de Mérida. Se determinó que la perra se encontraba en estro cuando a la citología vaginal exfoliativa se observó cuando menos un 90 por ciento de células anucleares y descamadas. Se utilizó estadística descriptiva para determinar la frecuencia y la distribución de perras en estro durante un año de muestreos. Se analizó el efecto de la condición corporal, tamaño y edad de las perras muestreadas sobre la presencia de estros mediante la prueba de chi cuadrada. Resultados. De las perras muestreadas, 33 (29 por ciento) se encontraban en estro. La mayor proporción de estros se observó en los meses de julio y agosto ; a excepción de los meses de enero y octubre en los que no se encontraron perras en estro, todos los demás meses del año se encontraron perras en estro, no observándose diferencia estadísticamente significativa. De las perras en estro, 22 (66 por ciento) eran jóvenes y 11 (33 por ciento) eran adultas (p>0.05); 19 (57 por ciento) eran perras chicas y 14 (43 por ciento) eran grandes (p<0.05). Se observó estro en 7 (21 por ciento) de perras con condición corporal buena y en 26 (78 por ciento) perras con condición corporal mala (p>0.05). Discusión. Se observó que las perras pueden presentar actividad estral durante todo el año, pero con mayor tendencia durante el verano. Las perras de tamaño pequeño tienen mayor probabilidad de presentar estro que las perras grandes, por entrar más temprano a la pubertad y por tener ciclos estrales de menor duración.

Descenso de la cadera con instrumental de Wagner: a propósito de tres casos

Presentamos la utilización del tutor externo de Wagner en 3 pacientes con una discrepancia de miembros, superior a los 6 cm. debida a patología de cadera. El procedimiento se realizó en 3 tiempos. Primer tiempo: liberación de las contracturas y retracciones (si existen) y colocación del tutor. Segundo tiempo: descenso progresivo y controlado del extremo femoral proximal. Tercer tiempo: extracción del tutor y técnica definitiva según patología de base. En el primer tiempo quirúrgico se consiguió un descenso promedio de 2,5 cm. En el segundo tiempo se logró un descenso promedio de 6,5 cm. El tiempo de uso del tutor fue en promedio de 26 días (17 y 34 días), no presentándose complicaciones asociadas al procedimiento

Descenso de la cadera con instrumental de Wagner: a propósito de tres casos

Presentamos la utilización del tutor externo de Wagner en 3 pacientes con una discrepancia de miembros, superior a los 6 cm. debida a patología de cadera. El procedimiento se realizó en 3 tiempos. Primer tiempo: liberación de las contracturas y retracciones (si existen) y colocación del tutor. Segundo tiempo: descenso progresivo y controlado del extremo femoral proximal. Tercer tiempo: extracción del tutor y técnica definitiva según patología de base. En el primer tiempo quirúrgico se consiguió un descenso promedio de 2,5 cm. En el segundo tiempo se logró un descenso promedio de 6,5 cm. El tiempo de uso del tutor fue en promedio de 26 días (17 y 34 días), no presentándose complicaciones asociadas al procedimiento