Recommendations on the use of azole antifungals in hematology-oncology patients.

The administration of antifungals for therapeutic and, especially, prophylactic purposes is virtually a constant in patients requiring hematology-oncology treatment. Any attempt to prevent or treat Aspergillus or Mucor infections requires the administration of some drugs in the azole group, which include voriconazole, posaconazole and isavuconazole, noted for their activity against these pathogens. One very relevant aspect is the potential risk of interaction when associated with one of the antineoplastic drugs used to treat hematologic tumors, with serious complications. In this regard, acalabrutinib, bortezomib, bosutinib, carfilzomib, cyclophosphamide, cyclosporine A, dasatinib, duvelisib, gilteritinib, glasdegib, ibrutinib, imatinib, nilotinib, ponatinib, prednisone, ruxolitinib, tacrolimus, all-transretinoic acid, arsenic trioxide, venetoclax, or any of the vinca alkaloids, are very clear examples of risk, in some cases because their clearance is reduced and in others because of increased risk of QTc prolongation, which is particularly evident when the drug of choice is voriconazole or posaconazole.

Tratamiento de la inestabilidad anterior de hombro con remplissage para lesiones de Hill-Sachs y lesión de Bankart comparado con lesiones de Bankart pura / Treatment of anterior shoulder instability with remplissage for Hill-Sachs injuries and Bankart injury compared to pure Bankart injuries

Resumen: Introducción: Las luxaciones anteriores de hombro ocurren en > 90% de las inestabilidades de hombro, la principal causa es traumática, describiéndose dos principales lesiones en esta patología: la lesión de Bankart y la de Hill-Sachs, existiendo una tasa de recurrencia similar en la reparación quirúrgica abierta y con ventaja de la cirugía artroscópica de realizar incisiones pequeñas, menor pérdida del rango de movimiento, menor riesgo de daño del músculo subescapular, retorno más rápido a las actividades diarias y mayor satisfacción de los pacientes. Objetivo: Valorar la funcionabilidad, movilidad y estabilidad postquirúrgica del hombro de los pacientes sometidos a tratamiento con dos técnicas artroscópicas: reparación de lesión de Bankart pura versus reparación Bankart + remplissage. Material y métodos: Se revisaron expedientes clínicos, se valoraron pacientes con inestabilidad de hombro y con lesiones de Hill-Sachs y Bankart; con un total de 21 pacientes postquirúrgicos se realizaron exploraciones físicas para valoración de los arcos de movimiento y aplicación de escalas funcionales de Rowe y Western Ontario Shoulder Instability Index, con el fin de medir la estabilidad postquirúrgica. Resultados: No hubo recurrencia de luxación con ninguna de las dos técnicas, se observó mayor satisfacción en el grupo de remplissage; sin embargo, la limitación del arco de movimiento es mayor. Conclusión: Ambas técnicas artroscópicas fueron capaces de restaurar la función, disminuir el dolor y satisfacer en su mayoría a los pacientes de nuestra serie de casos en el seguimiento a corto y mediano plazo.

Abstract: Background: Anterior shoulder dislocation occurs in more than 90% of the time, the main cause is traumatic, describing two main lesions in this pathology: Bankart's and Hill-Sachs's injury, the recurrence rate is not similar in open repair and with a possible advantage of arthroscopic surgery with less loss of movement range, lower risk of subscapular muscle damage, faster return to daily activities and increased patient satisfaction. Objective: Assessing functionality, mobility and stability of the shoulder in patients treated: arthroscopic Bankart repair versus arthroscopic Bankart repair + remplissage. Methods: Clinical records of patients with shoulder instability were reviewed Hill-Sachs and Bankart lesions were doumented; 21 post-surgical patients and were physically examined to evaluate the range of motion, Rowe functional scales and Western Ontario Shoulder Instability Index were used. 13 months of follow up as an average. Results: There was no recurrence of dislocation with either technique, greater satisfaction was observed in the remplissage group; however, the limitation of the motion arc is greater. Conclusion: Both groups reduce instability, control pain and mostly satisfy patients in the 13-month follow-up.

[Treatment of anterior shoulder instability with remplissage for Hill-Sachs injuries and Bankart injury compared to pure Bankart injuries]. / Tratamiento de la inestabilidad anterior de hombro con remplissage para lesiones de Hill-Sachs y lesión de Bankart comparado con lesiones de Bankart pura.

BACKGROUND: Anterior shoulder dislocation occurs in more than 90% of the time, the main cause is traumatic, describing two main lesions in this pathology: Bankarts and Hill-Sachss injury, the recurrence rate is not similar in open repair and with a possible advantage of arthroscopic surgery with less loss of movement range, lower risk of subscapular muscle damage, faster return to daily activities and increased patient satisfaction. OBJECTIVE: Assessing functionality, mobility and stability of the shoulder in patients treated: arthroscopic Bankart repair versus arthroscopic Bankart repair + remplissage. METHODS: Clinical records of patients with shoulder instability were reviewed Hill-Sachs and Bankart lesions were doumented; 21 post-surgical patients and were physically examined to evaluate the range of motion, Rowe functional scales and Western Ontario Shoulder Instability Index were used. 13 months of follow up as an average. RESULTS: There was no recurrence of dislocation with either technique, greater satisfaction was observed in the remplissage group; however, the limitation of the motion arc is greater. CONCLUSION: Both groups reduce instability, control pain and mostly satisfy patients in the 13-month follow-up.

INTRODUCCIÓN: Las luxaciones anteriores de hombro ocurren en 90% de las inestabilidades de hombro, la principal causa es traumática, describiéndose dos principales lesiones en esta patología: la lesión de Bankart y la de Hill-Sachs, existiendo una tasa de recurrencia similar en la reparación quirúrgica abierta y con ventaja de la cirugía artroscópica de realizar incisiones pequeñas, menor pérdida del rango de movimiento, menor riesgo de daño del músculo subescapular, retorno más rápido a las actividades diarias y mayor satisfacción de los pacientes. OBJETIVO: Valorar la funcionabilidad, movilidad y estabilidad postquirúrgica del hombro de los pacientes sometidos a tratamiento con dos técnicas artroscópicas: reparación de lesión de Bankart pura versus reparación Bankart + remplissage. MATERIAL Y MÉTODOS: Se revisaron expedientes clínicos, se valoraron pacientes con inestabilidad de hombro y con lesiones de Hill-Sachs y Bankart; con un total de 21 pacientes postquirúrgicos se realizaron exploraciones físicas para valoración de los arcos de movimiento y aplicación de escalas funcionales de Rowe y Western Ontario Shoulder Instability Index, con el fin de medir la estabilidad postquirúrgica. RESULTADOS: No hubo recurrencia de luxación con ninguna de las dos técnicas, se observó mayor satisfacción en el grupo de remplissage; sin embargo, la limitación del arco de movimiento es mayor. CONCLUSIÓN: Ambas técnicas artroscópicas fueron capaces de restaurar la función, disminuir el dolor y satisfacer en su mayoría a los pacientes de nuestra serie de casos en el seguimiento a corto y mediano plazo.

[Installed Capacity Perception Survey for the Training of Residents Program in Orthopedics and Care Needs in Acute and Chronic Musculoskeletal Pathology in Mexico]. / Encuesta de Percepción en Capacidad Instalada para la Formación de Médicos Residentes en Ortopedia (Traumatología) y Necesidades de la Atención en Patología Musculoesquelética Aguda y Crónica en México. Primera Parte.

INTRODUCTION: It is essential that orthopaedic resident physicians be highly proficient in all aspects, considering the balance between supply, demand, need and context. Fundamental to identify the capacity and quality installed for their training in Mexico. MATERIAL AND METHODS: Observational Study, transverse, non-probabilistic sampling-conglomerates, in two phases. The instrument has 8 domains, 57 variables and 4,867 items. 60 graduate professors of 20 states, 50 hospital sites, 22 university programs. RESULTS: 1,038 years of experience (collective intelligence), 17 years of experience/teacher (01 to 50 years). Identified: acute pathology 30 (2 to 90%), chronic pathology 30 (5 to 96%), patients 15 years, 10 (3 to 30%), patients between 15 and 65 years, 47 (2 to 78%), patients 65 years, 20 (2 to 60%), number of beds/seat 20 (2 to 510), number of clinics 3 (1 to 48), number of surgical procedures/headquarters per year at the national level, was 960 (50 to 24,650). The national average per resident doctor is 362 surgeries/year with 1,450 surgical times/year. CONCLUSIONS: The needs and resources for the training of physicians specializing in orthopedics/traumatology are highly heterogeneous, so it should be adapted to the epidemiological needs of the region of influence, in an area of epidemiological transition. 62.2% expressed not having or have bad academic and scientific infrastructure at its headquarters, more than 50% without rotation overseas and 90% without regular scientific production.

INTRODUCCIÓN: Es fundamental que los médicos residentes de ortopedia (traumatología) sean altamente competentes en todos los aspectos, considerando el equilibrio entre la oferta, demanda, necesidad y contexto. Es primordial identificar la capacidad y calidad instalada para su formación en México. MATERIAL Y MÉTODOS: Estudio observacional, transversal, muestreo no probabilístico-conglomerados, en dos fases. El instrumento tiene ocho dominios, 57 variables y 4,867 ítems. Sesenta profesores de postgrado de 20 estados, 50 sedes hospitalarias, 22 programas universitarios. RESULTADOS: 1,038 años de experiencia (inteligencia colectiva), 17 años de experiencia/profesor (01 a 50 años). Se identificó: patología aguda 30 (2 a 90%), patología crónica 30 (5 a 96%), pacientes 15 años, 10 (3 a 30%), pacientes entre 15 y 65 años, 47 (2 a 78%), pacientes 65 años, 20 (2 a 60%), número de camas/sede 20 (2 a 510), número de consultorios 3 (1 a 48), el número de procedimientos quirúrgicos/sede al año a nivel nacional fue de 960 (50 a 24,650). La media nacional por médico residente es de 362 cirugías/año con 1,450 momentos quirúrgicos/año. CONCLUSIONES: Las necesidades y recursos para la formación de médicos especialistas en ortopedia/traumatología son en alto grado heterogéneos, por lo cual se debería adaptar a las necesidades epidemiológicas de la región de influencia, en un ámbito de transición epidemiológica. Sesenta y dos punto dos por ciento expresó no tener o tener deficiente infraestructura académica y científica en su sede, más de 50% sin rotación al extranjero y 90% sin producción científica regular.

[Hemomediastinum caused by rupture of a bronchial artery aneurysm]. / Hemomediastino por rotura de aneurisma bronquial.

Hemomediastinum caused by rupture of a bronchial artery aneurysm is a very infrequent pathology. Clinical presentation can be variable; it can resemble an aortic pathology and be diagnosed in emergency situations. Computerized tomography (CT) of the thorax is the initial test for diagnosis. We present the clinical case of a 70-year-old man with an initial clinical assessment of transfixive thoracic pain resembling an acute aortic pathology. TC was carried out with a diagnosis of suspected mediastinal neoplasia (Hounsfield Units/HU 38 - soft tissue), biopsy sampling was carried out by gastroscopy and broncoscopy with haemorrhagic pap smear, presenting light anemization on admission and remaining haemodynamically stable and asymptomatic. Facing a high clinical suspicion of arterial pathology, CT was repeated in which hemomediastinum was described in resolution, with subsequent confirmation of the existence of ruptured bronchial artery aneurysm through angiography and proceeding to therapeutic embolization.

[Merkel cell carcinoma. On one case]. / Carcinoma de células de Merkel. A propósito de un caso.

We present the case of an 86 year old woman who was sent for consultation at General Surgery due to asymptomatic tumouration on the back face of the left thigh whose size had increased during the 2 previous months. Physical exploration revealed tumouration that was painless, excrescent, indurated, mobile and well delimited, with a diameter of 5 cm, a reddish colour and a rough surface. Tumoural extirpation was carried out with broad margins, with a hystopathological result of primary cutaneous neuro-endocrynal carcinoma or Merkel cell carcinoma. Computerised tomography was carried out, observing tumoural adenopathies in the para-aortic spaces, iliac chains and left femorals, as well as edema in the lower left extremity. The patient was sent to the Oncology service for treatment, without presenting a satisfactory evolution and with a progressive deterioration of her general state, dying within the first year after diagnosis.

[Intestinal endometriosis]. / Endometriosis intestinal.

Endometriosis is a chronic, benign gynaecological disorder that is frequent in women of a child-bearing age. It is estimated that there is some degree of endometriosis in as many as 15% of pre-menopausal women, associated with a history of infertility, caesarean antecedents, dysmenorrhoea and abnormality in uterine bleeding. It is believed to be due to the rise of menstrual contents through the Fallopian tubes (retrograde menstruation). In the intestinal affectation, the colon is the segment most frequently affected, above all at the rectosigmoidal level. The clinical features are unspecific, with abdominal pain the most frequent and/or pelvic pain of a cholic type that coincides with, or is exacerbated by, menstruation. Differential diagnosis includes intestinal inflammatory disease, diverticulitis, ischemic colitis and neoplastic processes, with the definitive diagnosis being anatomopathological. With respect to treatment, this will depend on the clinical features and the age of the patient, as well as her wishes with regard to pregnancy.

Post-marketing safety of antineoplasic monoclonal antibodies: rituximab and trastuzumab.

PURPOSE: The aim of this study was to analyse the suspected adverse reactions associated with rituximab or trastuzumab reported to the Spanish Pharmacovigilance System. METHODS: From this national database, we selected the spontaneous reports registered between 1 January 1999 and 1 June 2006 and analysed both age and gender of the patient, the dose prescribed, the severity of the report, the evolution, the latency and recovery periods of the adverse reaction, the reporting odds ratio (ROR) and the presence of other suspected drugs. RESULTS: From 49 927 records registered in the period of analysis, 69 were associated with rituximab and 23 with trastuzumab. White cell disorders (n = 18), hypotension (n = 7), dyspnoea (n = 6) and pneumonitis (n = 4) were the most common adverse reactions associated with rituximab. The mean latency period of white cell disorders was 20.9 +/- 7.8 days, except in two cases where it was clearly longer (87 +/- 13 days). Hypotension and dyspnoea appeared immediately or a few days after the administration of the drug, and rapidly resolved. Pneumonitis seems to be a delayed adverse reaction, which required on average, 3 months to develop. Cardiac failure was the adverse reaction more frequently associated with trastuzumab (n = 7). In five of the seven cases of cardiac failure reported patients had been taking other suspected medications. CONCLUSION: Our results are consistent with the safety profile of rituximab and trastuzumab observed in large randomised clinical trials.

Increased potency and longevity of gene silencing using validated Dicer substrates.

Chemically synthesized small interfering RNAs (siRNAs) are tools used for silencing the expression of a single gene. They are mainly employed in basic research applications, but may also have great potential in therapeutic applications. Longer double-stranded RNAs, such as Dicer-substrate 27mers, trigger gene silencing through the intrinsic RNAi pathway. The design of these Dicer-substrate 27mers has been optimized so they can be oriented by Dicer to consistently select the antisense (guide) strand after cleavage to shorter siRNAs, leading to predictable mRNA cleavage. In this paper we describe evidence that these Dicer-substrate 27mers produce more potent and sustained gene silencing for four genes when compared with synthetic 21mers that have the same guide-strand sequence. Furthermore, improved silencing by these 27mers is often more pronounced at lower concentrations.

[Calcinosis cutis: on one case]. / Calcinosis cutis: a propósito de un caso.

We present the case of a woman of 72 years with high blood pressure evaluated in Surgery Outpatient Unit for overinfected and recurring pretibial cutaneous ulcers. In the radiographies of the extremity, calcifications were observed in soft parts and the biopsy showed calcified subepidermic nodules. Because of these findings, she was sent to Internal Medicine Consultations to complete the study. In the anamnesis, traumatism in the zone was ruled out, and was there consumption of calcium or phosphorous rich medicines; the physical exploration was normal, except for the lesions described previously. A study was requested to rule out any underlying pathology that might justify the clinical picture, without a possible etiological pathological cause in evidence. Given that the cutaneous calcinosis of the patient was not secondary to titular lesions, nor was there evidence of metabolic alterations or medical procedures that might justify it, and no lesions at another level were found, the diagnosis was established of idiopathic localised cutaneous calcinosis. It was treated with diltiazem.

[Paget-Schroetter síndrome associated with hyperhomocsyteinemia]. / Síndrome de Paget-Schroetter asociado a hiperhomocisteinemia.

Venous thromboembolic disease (VTED) in the upper extremities is an infrequent entity, although its incidence has increased in relation to the use of central venous catheters. Its etiology can be primary (idiopathic, spontaneous, due to effort or traumatic) or secondary (related to tumours, central venous catheters, etc.). We present a case of primary venous thrombosis of the upper right extremity, also called the Paget-Schroetter syndrome. This clinical picture is usually associated with intensive and/or repetitive exercise or effort of the affected extremity, anatomical alterations in the zone, or it can be the first manifestation of a previously unknown thrombophilic state, as in the case that concerns us. The clinical picture usually consists of pain in the affected extremity, frequently accompanied by edema and collateral circulation. Echography-Doppler frequently presents false negatives, and it is recommendable to carry out CAT, due to its greater specificity and for evaluating the neighbouring structures, although flebography continues to be the cardinal test for diagnosing this picture. There is no unanimity of opinion concerning treatment, and it is recommendable that this should be individualised in accordance with the characteristics of each case.

[Abdominal tuberculosis]. / Tuberculosis abdominal.

Abdominal tuberculosis develops according to a non-specific clinical picture, with a difficult differential diagnosis with respect to other entities of similar semiology. We present the case of a male who was admitted because of abdominal pain, progressive and notable loss of body weight and a fever of two months evolution. The culture from the colon biopsy showed the presence of Koch bacilli.

[Intestinal invagination in the adult secondary to jejunal lipoma]. / Invaginación intestinal en el adulto secundaria a lipoma yeyunal.

Small bowel intussusception is an unusual pathology in the adult. Most commonly, it is secondary to intestinal wall organic disorders. A complete small bowel obstruction is the most frequent clinical presentation, which requires emergency surgery in many cases. The preoperative diagnosis is infrequent. The best treatment is surgical resection.

[Distribution of pulmonologists and chest surgeons in Spain]. / Distribución de neumólogos y cirujanos torácicos en España.

OBJECTIVE: To study the real situation of respiratory medicine specialists and chest surgeons in the Spanish health service. SUBJECTS AND METHOD: Using the database of the secretary of the Spanish Society of Respiratory Medicine and Chest Surgery (SEPAR) for 1999, we gathered data on 326 Spanish hospitals. We were thus able to ascertain the level of staffing of respiratory medicine and chest surgery departments. The results were expressed as simple percentages showing distribution by age, duties and geographic area. The number of specialists per 100,000 inhabitants in each community was also calculated based on population data provided by the National Statistics Institute for 1997. RESULTS: We studied 1,786 physicians or surgeons (1,245 pneumologists, 185 surgeons and 356 from other specialties). The mean age was 41 9 years for pneumologists, 44 10 years for surgeons and 51 8 years for the others. We observed unequal distribution by geographic area, with a high of 6.66 pneumologists and 0.9 surgeons per 100,000 inhabitants in Asturias and Madrid, respectively and a low of 1.4 pneumologists per 100,000 inhabitants in Murcia and 0 surgeons in Extremadura. CONCLUSIONS: Specialist coverage by pneumologists and chest surgeons is inadequate in many provinces and communities in Spain. The professional market is not saturated, indicating that future specialists can look forward to market demand.

Abdominal actinomycosis with hydronephrosis in childhood.

Two 11-year-old boys had similar clinical courses of abdominal actinomycosis complicating ruptured appendicitis and manifesting as abdominal masses causing hydronephrosis. Cure was effected by surgery and prolonged penicillin therapy.

[Comparative study of the efficacy of 2 respiratory physiotherapy protocols for patients with cystic fibrosis]. / Estudio comparativo de la eficacia de dos protocolos de fisioterapia respiratoria en pacientes con fibrosis quística.

OBJECTIVE: To compare the short-term efficacy of two respiratory physiotherapy protocols on sputum clearance, lung function and symptoms in patients with cystic fibrosis. Treatment A consisted of diaphragm breathing with incentive spirometry and postural drainage. Treatment B consisted of diaphragm breathing with positive expiratory pressure (PEP-mask) and postural drainage. METHODS: Twenty-seven cystic fibrosis patients in stable condition followed both protocols (A and B) in random order on different days separated by at least 48 hours. After each treatment session the amount of sputum removed was weighed. Lung function variables (FVC, FEV1, FEV1%, MMEFwt-75, MVV and PEF) were measured pre- and posttreatment. PEF was measured with a peak flow meter. The patients later recorded PEF every hour at home and filled in a questionnaire on frequency and intensity of coughing, sputum characteristics, chest discomfort and dyspnea. RESULTS: During treatment A with incentive spirometry, 14.6 +/- 13.7 g of sputum was removed, whereas 9.8 +/- 10.2 g was eliminated during treatment B (p < 0.05). The differences in PEF after treatments A and B in comparison with baseline values were +19.3 l/min and -0.2 l/min, respectively (p < 0.01). PEF stayed high during the afternoon, in comparison with baseline, with treatment A (p < 0.02). After treatment B, no changes in PEF in comparison with baseline were observed (p = 0.49). Neither treatment led to significant differences in symptoms reported on the clinical questionnaire. CONCLUSIONS: Respiratory physiotherapy with incentive spirometry significantly increases sputum clearance in cystic fibrosis patients, with no immediate repercussions on lung function or symptoms.

Broad-spectrum protection against tombusviruses elicited by defective interfering RNAs in transgenic plants.

We have designed a DNA cassette to transcribe defective interfering (DI) RNAs of tomato bushy stunt virus (TBSV) and have investigated their potential to protect transgenic Nicotiana benthamiana plants from tombusvirus infections. To produce RNAs with authentic 5' and 3' termini identical to those of the native B10 DI RNA, the DI RNA sequences were flanked by ribozymes (RzDI). When RzDI RNAs transcribed in vitro were mixed with parental TBSV transcripts and inoculated into protoplasts or plants, they became amplified, reduced the accumulation of the parental RNA, and mediated attenuation of the lethal syndrome characteristic of TBSV infections. Analysis of F1 and F2 RzDI transformants indicated that uninfected plants expressed the DI RNAs in low abundance, but these RNAs were amplified to very high levels during TBSV infection. By two weeks postinoculation with TBSV, all untransformed N. benthamiana plants and transformed negative controls died. Although infection of transgenic RzDI plants initially induced moderate to severe symptoms, these plants subsequently recovered, flowered, and set seed. Plants from the same transgenic lines also exhibited broad-spectrum protection against related tombusviruses but remained susceptible to a distantly related tombus-like virus and to unrelated viruses.

Comparison of a beta-lactam alone versus beta-lactam and an aminoglycoside for pulmonary exacerbation in cystic fibrosis.

UNLABELLED: We determined whether a beta-lactam and an aminoglycoside have efficacy greater than a beta-lactam alone in the management of a pulmonary exacerbation in patients with cystic fibrosis. STUDY DESIGN: Azlocillin and placebo or azlocillin and tobramycin were administered to 76 patients with a pulmonary exacerbation caused by Pseudomonas aeruginosa in a randomized double-blind, third-party monitored protocol. Improvement was assessed by standardized clinical evaluation, pulmonary function testing, sputum bacterial density, sputum DNA content, and time to the next pulmonary exacerbation requiring hospitalization. RESULTS: No significant difference was seen between the 2 treatment groups in clinical evaluation, sputum DNA concentration, forced vital capacity, forced expiratory volume in second 1, or peak expiratory flow rate at the end of treatment (33 receiving azlocillin alone and 43 both antibiotics); adverse reactions were equivalent in each group. Sputum P. aeruginosa density decreased more with combination therapy (P =.034). On follow-up evaluation, an average of 26 days after the end of treatment, all outcome indicators had worsened in both groups. Time to readmission for a new pulmonary exacerbation was significantly longer in the group receiving azlocillin plus tobramycin (P <.001). Treatment-emergent tobramycin resistance occurred in both groups and was more frequent with combination therapy. CONCLUSION: We conclude that the combination of a beta-lactam and an aminoglycoside produces a longer clinical remission than a beta-lactam alone and slightly better initial improvement.

Restoration of wild-type virus by double recombination of tombusvirus mutants with a host transgene.

Nicotiana benthamiana plants transformed with the coat protein gene of tomato bushy stunt virus (TBSV) failed to elicit effective virus resistance when inoculated with wildtype virus. Subsequently, R1 and R2 progeny from 13 transgenic lines were inoculated with a TBSV mutant containing a defective coat protein gene. Mild symptoms typical of those elicited in nontransformed plants infected with the TBSV mutant initially appeared. However, within 2 to 4 weeks, up to 20% of the transgenic plants sporadically began to develop the lethal syndrome characteristic of wild-type virus infections. RNA hybridization and immunoblot analyses of these plants and nontransformed N. benthamiana inoculated with virus from the transgenic lines indicated that wild-type virus had been regenerated by a double recombination event between the defective virus and the coat protein transgene. Similar results were obtained with a TBSV deletion mutant containing a nucleotide sequence marker, and with a chimeric cucumber necrosis virus (CNV) containing the defective TBSV coat protein gene. In both cases, purified virions contained wild-type TBSV RNA or CNV chimeric RNA derived by recombination with the transgenic coat protein mRNA. These results thus demonstrate that recombinant tombus-viruses can arise frequently from viral genes expressed in transgenic plants.

A tandem array of Sp-1 sites and a reverse initiator element are both required for synergistic transcriptional activation of the T-cell-specific MAL gene.

We have characterized the three cis elements responsible for promoter strength present in the 5'-flanking proximal region of MAL, a human T-cell-specific gene encoding a proteolipid protein present in detergent-insoluble complexes of high molecular weight. The first element consisted of an initiator sequence that, curiously, was present in reverse orientation compared to that of the standard initiator elements. The other two elements were contained in a region of 126 bp upstream of the mRNA initiation site, and consisted of a tandem array of one GC box and one GA box. The GC box corresponds to a consensus site for the nuclear factor Sp1, whereas the GA box deviates from this consensus, although it was able to compete for the binding of Sp1 in vitro and to respond to trans-activation by Sp1 in vivo. This simple promoter lacks an apparent TATA box and lost more than 99% of its activity when a fragment of 60 bp containing the GC and GA boxes was deleted. A synergistic effect on transcriptional activation was observed in the presence, but not in the absence, of the initiator element when both GC and GA boxes were present.