Eventos de aparente amenaza a la vida: diagnóstico y manejo en lactantes / Apparent life threatening events: Diagnosis and management in infants

Introducción: un evento de aparente amenaza a la vida (ALTE) es una combinación variable de apnea, cambio de coloración y del tono muscular que se puede presentar en menores de dos años y que atemoriza al observador. El médico del Servicio de Urgencias necesita una guía para orientar su conducta con estos niños. Objetivos: determinar las etiologías y el manejo adecuado de niños con ALTE mediante un protocolo de investigación inicial. Material y métodos: estudio prospectivo en lactantes que consultaron en un Servicio de Urgencias por ALTE entre mayo 2002 a mayo 2003. Se confeccionó un protocolo con la descripción del episodio, antecedentes y estudio complementario por etapas. Resultados: en 46 pacientes con ALTE, de edad promedio doce semanas, se observó apnea y cambio de color en el 100 por ciento. El 85 por ciento presentó hipotonia y el 96 por ciento requirió maniobras de resucitación. Las principales etiologías observadas fueron: infecciones respiratorias (54 por ciento), reflujo gastroesofágico (15 por ciento), convulsiones (9 por ciento), infecciones urinarias (7 por ciento). Fallecieron 3 pacientes y recibieron monitoreo domiciliario 5 pacientes. Conclusiones: las etiologías de ALTE más frecuentes fueron infecciones respiratorias, reflujo gastroesofágico y convulsiones. El protocolo ayudó en el manejo, tratamiento y monitoreo domiciliario en caso necesario (AU)

Cytosolic levels of neuron-specific enolase in squamous cell carcinomas of the lung.

To study the behavior and possible correlations of neuron-specific enolase (NSE) with other clinicobiological parameters, we measured the cytosolic levels of this marker by means of an immunoradiometric assay (IRMA) in 95 squamous cell lung carcinoma samples. We also analyzed the levels of pS2, tissue-type plasminogen activator (t-PA), hyaluronic acid (HA), free beta subunit of human chorionic gonadotropin (beta-HCG), CYFRA 21.1 and CA 125 in cytosol. On the cell surface we analyzed the concentrations of epidermal growth factor receptor (EGFR), HA, erbB-2 oncoprotein, CD44s, CD44v5 and CD44v6. Other parameters considered were clinical stage, lymph node involvement, histological grade (HG), ploidy and the cellular S-phase fraction measured by flow cytometry on nuclei obtained from fresh tissues. In the 95 squamous cell carcinomas the cytosolic levels of NSE varied from 4.5 to 2235 ng/mg protein (median: 267) and were significantly higher (p < 0.001) than those observed in 38 samples of normal pulmonary tissue obtained from the same patients (range: 56-657; median: 141.5). When classifying tumors according to the different parameters analyzed, we observed that the levels of NSE were higher in aneuploid than in diploid cases (p = 0.046) and in those that were HG3 than in those that were HG2 (p < 0.001). Tumors with high NSE levels (> 422 ng/mg protein; 75th percentile) were more likely to have high S-phase values (p = 0.012) and were more frequently aneuploid (p = 0.038) and HG3 (p < 0.001) than those with low levels of NSE (< 180 ng/mg protein; 25th percentile). These results lead us to the following conclusions: 1) the cytosolic concentrations of NSE are significantly higher in squamous cell carcinomas than in healthy pulmonary tissue, and 2) the cytosolic concentrations of NSE are not correlated with clinical stage or nodal involvement. However, in our study higher levels of the enzyme were statistically correlated with aneuploidy, histological grade 3 and S-phase. This may explain its association with poorer outcome and progression, but also the more favorable response of tumors with elevated NSE to chemotherapy, as suggested by other groups.

Immunohistochemical localization and distribution of VIP/PACAP receptors in human lung.

VIP and PACAP are distributed in nerve fibers throughout the respiratory tract acting as potent bronchodilators and secretory agents. By using RT-PCR and immunoblotting techniques, we have previously shown the expression of common VIP/PACAP (VPAC(1) and VPAC(2)) and specific PACAP (PAC(1)) receptors in human lung. Here we extend our aims to investigate by immunohistochemistry their localization and distribution at this level. A clear immunopositive reaction was obtained in human lung sections by using either anti-VPAC(1) or -VPAC(2) receptor antibodies but not with anti-PAC(1) receptor antibody. However, PAC(1) receptor (and VPAC(1) and VPAC(2) receptors) could be identified in lung membranes by immunoblotting which supports that the PAC(1) receptor is expressed at a low density. Both VPAC(1) and VPAC(2) receptors showed similar immunohistochemical patterns appearing in smooth muscle cells in the wall of blood vessels and in white blood cells (mainly in areas with inflammatory responses). The results agree with previous evidence on the importance of both peptides in the immune system and support their anti-inflammatory and protective roles in lung.

Expression, pharmacological, and functional evidence for PACAP/VIP receptors in human lung.

Pituitary adenylate cyclase-activating peptide (PACAP) type 1 (PAC(1)) and common PACAP/vasoactive intestinal peptide (VIP) type 1 and 2 (VPAC(1) and VPAC(2), respectively) receptors were detected in the human lung by RT-PCR. The proteins were identified by immunoblotting at 72, 67, and 68 kDa, respectively. One class of PACAP receptors was defined from (125)I-labeled PACAP-27 binding experiments (dissociation constant = 5.2 nM; maximum binding capacity = 5.2 pmol/mg protein) with a specificity: PACAP-27 approximately VIP > helodermin approximately peptide histidine-methionine (PHM) >> secretin. Two classes of VIP receptors were established with (125)I-VIP (dissociation constants of 5.4 and 197 nM) with a specificity: VIP approximately helodermin approximately PACAP-27 >> PHM >> secretin. PACAP-27 and VIP were equipotent on adenylyl cyclase stimulation (EC(50) = 1.6 nM), whereas other peptides showed lower potency (helodermin > PHM >> secretin). PACAP/VIP antagonists supported that PACAP-27 acts in the human lung through either specific receptors or common PACAP/VIP receptors. The present results are the first demonstration of the presence of PAC(1) receptors and extend our knowledge of common PACAP/VIP receptors in the human lung.

[The factors associated with a lengthy hospital stay in a third-level unit]. / Los factores asociados con la estancia hospitalaria prolongada en una unidad de tercer nivel.

A descriptive, cross-sectional and retrospective design was developed in order to assess the frequency of patients with lengthy hospital stay (LHS) and associated factors at the Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, in Mexico City from January to April, 1993. Some 2,488 patients were discharged during this period and 541 were selected at random. There were 23.9% (n = 131) of patients who had LHS, with a specific mean of 7.7 days and a total mean of 18 days of hospital stay compared with 5 days for those patients who did not have LHS. The associated factors were: patient's origin, admission conditions, complications, hospital infections, category and specialty of attending physician, delay in laboratory and diagnostic imaging exams and results, delay in surgical interventions, and need of outside transportation at time of discharge. Characteristics of patients with greater probabilities of having LHS are outside origin, diagnosis of malignant tumor, complications, hospital infections, and delay in laboratory exams and in surgical interventions. Some of these characteristics can be modified in order to improve LHS and quality of medical care. Further investigations are required to individually analyze these characteristics as well as the justification for LHS and its costs.

[The treatment of tracheobronchial ruptures: a review of 6 cases]. / Tratamiento de las roturas traqueobronquiales: revisión de 6 casos.

Tracheobronchial ruptures represent a serious pathology difficult to diagnose at the first examination. The authors review 6 cases: four as acute types with pneumomediastinum, pneumothorax and subcutaneous emphysema with a delay in diagnosis of 3.25 days, meanwhile 2 cases were chronic forms with a delay in diagnosis of 124.5 days. Diagnosis should be performed as soon as possible based in the presence of uni or bilateral pneumothorax with pneumomediastinum being confirmed by fiber bronchoscopy. The treatment is based in the resection of the fractured fragments, followed by bronchoplasty always with reabsorbable sutures the most frequent surgical technique, meanwhile in the atelectatic forms it is not possible to perform sometimes and we must practise lung resections.

Ocular tolerance of sertaconazole gel.

The in vitro and in vivo tolerance of sertaconazole gel, a new topical azole antifungal, was studied. Ketoconazole gel (Panfungol) was used as a reference substance. The methods applied for tolerance assessment were the bovine corneal opacity and permeability test for the in vitro assay and a modified Draize test for the in vivo assay. The results obtained show that both substances can be classified as slightly irritant and with acceptable tolerance. However, unlike ketoconazole gel, sertaconazole gel did not cause a positive lesion index in vivo. Ketoconazole was 5.25 times more irritant in vitro than sertaconazole gel, whose effect was similar to that of saline solution. Consequently, the negligible irritant effect of sertaconazole gel on a type of epithelium that is extremely sensitive, i.e. the cornea, confirms the good tolerance of this new antifungal gel on other structures such as the skin and mucous membranes.

[An epidemiological study on the relations of patients with hydatid disease. A high-risk population?]. / Estudio epidemiológico en familiares de pacientes con enfermedad hidatídica. Población de alto riesgo?

A serological study was undertaken by means of indirect hemagglutination (IHA) in 57 households of eleven patients with confirmed pulmonary hydatidosis (by serology and surgical procedure). Serum samples from 40 blood donors were used as control group. The IHA positivity rates were 90.8%, 40.3% (23/57) and 2.5% (1/40) in patients with hydatidosis, households of these patients and blood donors (control group). Hydatidosis was confirmed in 4 out of 23 cases of IHA positive households. The high incidence by IHA in households living with patients with hydatid disease can be a good screening parameter to identify a high-risk asymptomatic population carrying the disease at an early phase.

[Therapeutic alternatives in complicated nonsurgical pulmonary aspergillomas]. / Alternativa terapéutica para los aspergilomas pulmonares complicados no quirúrgicos.

We present 2 patients with pulmonary aspergilloma complicated by massive hemoptysis who were not good candidates for surgery and were treated with intracavitary amphotericin B after arterial embolization failed. In spite of the size of the mycetomas, response to treatment was excellent with full regression of the aspergilloma after 3 to 4 weeks; precipitins to Aspergillus fumigatus became negative and the fungus disappeared from transcatheter aspirate samples. Massive hemoptysis was controlled with epsilon-amino-caproic acid instilled by catheter. No complications were observed, the treatment was well tolerated and no recurrence occurred over a follow-up period of 24 and 18 months, respectively. This local treatment is the best therapeutic alternative for patients with pulmonary aspergilloma who are not candidates for surgery.

Bronchovascular mucormycosis: an urgent surgical problem.

The case of a 70-year-old male with lymphoblastic leukemia is reviewed, who presented the rare and almost always fatal complication of pulmonary mucormycosis, but who was treated satisfactorily with amphotericin B and surgery. The risk of massive hemoptysis in the course of mucormycosis that invades the lung vessels, makes us believe that surgery is an essential part of the management of this disease. It is suggested that the patient be operated as soon as the diagnosis is obtained, as we did in our case, to avoid other risks in combined management with amphotericin B.

[Primary sternal hemangiosarcoma]. / Hemangiosarcoma esternal primario.

We describe a 22-year-old man with a bone mass in the middle and lower third of the sternum with no signs of respiratory deterioration. After biopsy by incision established a diagnosis of hemangiosarcoma, appropriate resection and repair of the thoracic wall was scheduled. An adequate amount of tissue for analysis must be obtained to allow choice of a surgical technique that will assure the best prognosis in malignant tumors of the sternum and assignation of the most appropriate mechanical ventilation procedure.

Thoracotomy in patients over 70 years old.

One hundred cases of patients aged 70 yrs or older, who had undergone surgical intervention for a thoracic pathology between 1981 and 1990, were reviewed. The mean age was 73 yrs, and bronchial cancer the most frequent aetiology (55%). A systematic detailed study before surgery is recommended in the these patients, who have the highest operative risk, and whom we should try to treat most conservatively. Although the rate of complications was higher than the normal average, mortality was only 4%, and was related to the greater or lesser aggression of the surgery. In cases of diagnosed bronchial cancer, a survival of 2 yrs was obtained in 66%, 3 yrs in 50%, and 5 yrs in 26%. We conclude that, theoretically, at the age of 70 yrs or older there is no contraindication for surgery, although it does increase the postoperative morbidity.

Prognostic factors in pulmonary metastases from colorectal cancer.

Surgery represents the first-choice treatment to manage pulmonary metastases from colorectal cancer when the primary tumor has been controlled and there is no evidence of metastatic spreading to any other organ. In our experience on 13 patients, we obtained a survival at 5 years of 23%. The average number of metastases resected was 2.9. The increase of carcinoembryonic antigen was the first clinical sign in 10 cases (76.9%, higher or equal to 5 ng/ml) that led to its discovery. The surgical technique most frequently used was wedge resection and/or atypical segmentectomy. Intraoperative mortality was zero and morbidity low (15.3%).

Vascular clearance of Borrelia burgdorferi in rats.

Radiolabeled Borrelia burgdorferi, the etiologic agent of Lyme disease, injected intravenously into rats are cleared from the vasculature within 1 h of injection. One low passage isolate showed trafficking between the circulation and possibly the vessel walls for the first 2 h after injection. All strains used were resistant to the effects of normal and heat-inactivated rat serum. During the first 2 h after injection, B. burgdorferi can be visualized in, and recovered from, the platelet-rich plasma. B. burgdorferi can adhere to both human and rat platelets in in vitro assays, but an in vivo association with these cells was not apparent. Similarly, none of the strains of B. burgdorferi used induced platelet aggregation. Removal from the circulation into the organs was measured in perfused rats by polymerase chain reaction and autoradiography and in non-perfused rats by organ cultures. These organisms invade organs (heart, kidneys, bladder, liver, spleen, brain) within 1-6 h after injection. Invasion of organs occurred in an apparent random manner; a large amount of radiolabel but no live organisms was excreted in the urine during the first 24 h, suggesting degradation of the inoculum.

Toxicity studies with flutrimazole.

Studies with 1-[(2-fluorophenyl)(4-fluorophenyl)phenylmethyl]-1H- imidazole (flutrimazole, CAS 119006-77-8), a new topical imidazole antifungal agent, have been carried out to investigate the acute toxicity of the active substance in mice and rats, as well as the acute ocular and dermal irritation in rabbits, the dermal tolerance after repeated dose (21 days) applications in rabbits, and the sensitising, photoallergic and phototoxic potential in guinea pigs using 1% flutrimazole cream. LD50 values after oral or intraperitoneal administration were greater than or equal to 1000 mg/kg in both mice and rats, which reveal a very low acute toxicity of flutrimazole. No differences were found between the excipient and 1% flutrimazole cream in the acute ocular and dermal irritation studies in rabbits, the irritation indexes being indicative of no lesions due to flutrimazole. Cumulative dermal irritation studies in rabbits showed an improved local tolerance of a skin cream containing 1% flutrimazole as compared to a commercial skin cream containing 1% clotrimazole. The irritation indexes were 1.2 and 3.7, respectively (p less than 0.01). The corresponding histophatological findings confirmed the better local tolerance of 1% flutrimazole cream. Furthermore, it has been found that flutrimazole cream lacks sensitising potential (Magnusson and Kligman test), is also devoid of phototoxic potential and does not induce photoallergic reactions in guinea pigs, these data being confirmed by histopathological studies. These results, together with the very slight systemic absorption rate of flutrimazole from the 1% topical drug form, clearly show that no restrictions should be taken in the use of the cream for reasons of systemic toxicity or dermal tolerance.

Gigant carcinosarcoma.

We present a case with gigantic carcinosarcoma (the largest described to date, diameter of 20.5 cm), located in the right upper lobe, in which the discordance between the brief clinical course with limited symptoms and its large size were remarkable. Preoperative diagnosis by bronchial biopsy, as used to be the case in this malignancy, was incorrect (epidermoid), and the define histological characterization was made by thoracotomy. The controversy about pathology, diagnosis and treatment of the carcinosarcoma is discussed.