Effect of chronic pain on morphine-induced respiratory depression in mice.

Respiratory depression is the most well-known and dangerous side-effect of opioid analgesics. Clinical investigations have revealed that this opioid-induced respiratory depression is less severe in patients with chronic pain, but the mechanisms that underlie this phenomenon are unknown. Therefore, the present study was designed to examine the influence of chronic pain on morphine-induced respiratory depression. Respiration was detected by double-chamber, flow-through whole-body plethysmography. Respiratory frequency was dose-dependently and significantly decreased after morphine administration. This effect peaked at 30 min after administration and lasted 3 h. In contrast, tidal volume was increased. Minute volume was significantly decreased by morphine at a higher dose, but not a lower dose. In nerve-ligated mice, a morphine-induced decrease in respiratory frequency was observed, whereas the increase of tidal volume was more prominent. A decrease in minute volume was not observed in nerve-ligated mice. This attenuation of the morphine-induced decrease in minute volume in nerve-ligated mice was reversed by treatment with the serotonin (5-HT)4a receptor antagonist GR125487. Moreover, treatment with the 5-HT4 receptor agonist mosapride antagonized the morphine-induced decrease in minute volume, due to the enhancement of tidal volume. Finally, the expression of 5-HT4a receptor in the brainstem was enhanced in nerve-ligated mice compared to that in sham-operated mice. These results suggest that the decrease in morphine-induced respiratory depression under chronic pain is mediated by the enhancement of 5-HT4a receptor systems in the brainstem.

Estudo anatômico de folha e caule de Pereskia aculeata Mill. (Cactaceae) / Anatomical study of the leaf and stem of Pereskia aculeata Mill. (Cactaceae)

Pereskia aculeata Mill. (Cactaceae) é uma trepadeira arbustiva conhecida comumente como ora-pro-nobis. Apresenta elevado teor de mucilagem e proteína, sendo empregada na indústria alimentícia e farmacêutica. Na medicina popular, é utilizada externamente como emoliente. Este trabalho teve por objetivo estudar a anatomia foliar e caulinar da planta, a fim de fornecer informações complementares à sua identificação e aplicáveis ao seu controle de qualidade. Folhas adultas e fragmentos de caules foram fixados, seccionados à mão livre e corados com azul de astra e fucsina básica ou com azul de toluidina. Testes histoquímicos e análise ultra-estrutural de superfície foram realizados. A folha é simples e elíptica. Possui epiderme uniestratificada, estômatos paracíticos em ambas as faces, mesofilo que tende a ser dorsiventral, contendo numerosas drusas de oxalato de cálcio e células isodiamétricas grandes com conteúdo mucilaginoso. A nervura central é percorrida por um feixe vascular colateral em arco aberto. O pecíolo tem secção plano-convexa e um feixe colateral em formato de arco fechado. O caule, em estrutura secundária incipiente, possui epiderme unisseriada, colênquima angular, parênquima cortical com muitos amiloplastos, calotas de fibras perivasculares e organização vascular colateral. No córtex e na medula, são observadas numerosas cavidades com conteúdo mucilaginoso e drusas de oxalato de cálcio, estas também presentes no floema.

Pereskia aculeata Mill. (Cactaceae) is a climbing shrub commonly known as Barbados gooseberry. It has high mucilage and protein content and it is employed in the food and pharmaceutical industry. In traditional medicine, P. aculeata is used externally as emollient. This work aimed to study the leaf and stem anatomy of this plant, in order to supply additional information for its identification and quality control. Mature leaves and stem fragments were fixed, freehand sectioned and stained either with astra blue and basic fuchsine or toluidine blue. Histochemical tests and ultrastructure analysis were carried out. The leaf is simple and elliptical, and has uniseriate epidermis, paracytic stomata on both surfaces, dorsiventral-like mesophyll, several druses of calcium oxalate and large isodiametric cells containing mucilage. In the midrib a collateral bundle in open arc is embedded. The petiole exhibits a plain-convex transection and a collateral bundle in closed arc shape. The stem, in incipient secondary growth, has uniseriate epidermis, angular collenchyma, cortical parenchyma with many amiloplasts, perivascular fibre caps and collateral vascular organization. In the cortex and pith, numerous cavities containing mucilage and druses of calcium oxalate are seen, the latter also in the phloem.

Partial tricuspid valve transfer for repair of mitral insufficiency due to ruptured chordae tendineae.

BACKGROUND: A new technique is suggested for the reconstructive surgical treatment of mitral regurgitation. It involves partial transfer of the tricuspid valve of the patient to the mitral valve, in order to provide chordae to correct anterior leaflet prolapse of the mitral valve, secondary to rupture of the chordae tendineae. METHODS: From January 1991 to May 1997, 20 patients with mitral insufficiency due to rupture of the chordae were operated on. The prevailing cause was myxomatous degeneration (70%). Patients were in New York Heart Association functional class III and IV. RESULTS: There were no hospital deaths. Two patients were reoperated on. Eighteen patients (90%) are alive with their own valves (class I and II). Doppler echocardiogram mean values were: ejection fraction, 0.65; left atrial diameter, 4.2 cm; mitral area, 2.4 cm2; mitral transvalvular gradient, 3.3 mm Hg. No regurgitation or mild regurgitation was observed in 16 (94.1%) of the 17 cases evaluated. Mean tricuspid valvular area was 3.3 cm2. In all cases, no tricuspid regurgitation was present or it was mild. CONCLUSIONS: Partial transfer of the tricuspid valve to the mitral valve is an effective procedure for the surgical treatment of mitral valve insufficiency secondary to ruptured chordae tendineae of the anterior leaflet.

[Surgical correction of anomalous venous connection of the left lung without extracorporeal circulation]. / Correção cirúrgica da conexão venosa anômala do pulmão esquerdo sem circulação extracorpórea.

Surgical correction of anomalous pulmonary venous connection from the left lung to the innominate vein (through a vertical vein) without cardiopulmonary bypass, was performed in two patients, with excellent evolution. After median sternotomy, the ascending vertical vein was cut obliquely close to the vein, and connected to the left atrial appendage. In the postoperative period, the patients were in NYHA class I and the hemodynamic study showed normal venous drainage from the left lung to the left atrium.

Mitral valvuloplasty with a new prosthetic ring. Analysis of the first 105 cases.

From October 1987 to March 1993, 105 patients were studied who have undergone valvuloplasty with an open ring. They ranged from 5 to 79 years (mean 30); 33 (31.4%) were under 16. All patients had mitral insufficiency, alone in 62 (59.0%) and associated with mitral stenosis (double mitral lesion) in 43 (41.0%). In the majority of the cases, the aetiology was rheumatic (78.1%); active in 10 (9.5%) patients. Three patients (2.9%) were in class II, 42 (40.0%) in class III, 57 (54.3%) in class IV and 3 (2.9%) in class V. Ten patients (9.5%) had isolated ring implantation while the remaining underwent associated procedures on the leaflets, chordae and papillary muscles. There were two (1.9%) hospital deaths, and six patients (5.7%) had to be reoperated. On the 30th (mean) postoperative day, 75 (71.4%) patients were reevaluated by catheterization, echo Doppler or both to confirm the effectiveness of the techniques employed. The mitral valve was functioning normally or with mitral regurgitation + in 63 (84.0%) patients, mitral regurgitation + + in 2 (2.7%), mitral regurgitation + + + in 5 (6.7%), mitral stenosis + in 4 (5.3%), and mitral stenosis + + in 1 (1.3%) patient. The results were therefore considered excellent in 63 (84.0%) patients with either normal mitral valve or mitral regurgitation +, good in 6 (8.0%) patients with mitral regurgitation + + and/or mitral stenosis +, and poor in 6 (8.0%) patients with mitral regurgitation + + + and/or mitral stenosis + +. Two deaths (1.9%) occurred within the first 7 months of follow-up. Patients were evaluated clinically 1-67 months postoperatively (mean 27):90 (85.7%) were in class I, 4 (3.8%) in class II, 4 (3.8%) in class III and 1 (1.0%) in class IV.(ABSTRACT TRUNCATED AT 250 WORDS)

[A new reconstructive technique in cases of mitral insufficiency caused by the elongation of the chordae tendineae of the anterior cusp. A case report]. / Nova técnica reconstrutora na insuficiência mitral por alongamento das cordas tendíneas da cúspide anterior. Relato de caso.

A new technique is proposed for mitral incompetence due to elongated chordae tendineae of the anterior leaflet. It consists in shortening the chordae tendineae of the leaflet level. First, we make a longitudinal orifice in the anterior leaflet just near its free edge and the elongated chordae tendineae. Through the orifice and with the help of a micro nerve hook we pull the elongated chordae the necessary to keep the anterior leaflet in the same level of the posterior leaflet. The orifice is then closed with a polipropilene 5-0 suture. The mitral annuloplasty was performed with a Gregori IMC prosthetic ring. The excellent clinical and laboratorial data suggest that mitral insufficiency due to elongated chordae tendineae can be corrected by this technique.