Effect of salbutamol on innervated and denervated rat soleus muscle

The objective of the present investigation was to perform a 14-day time-course study of treatment with salbutamol, a ß2 adrenoceptor agonist, on rat soleus muscle in order to assess fiber type selectivity in the hypertrophic response and fiber type composition. Male Wistar rats were divided into four groups: control (N = 10), treated with salbutamol (N = 30), denervated (N = 30), and treated with salbutamol after denervation (N = 30). Salbutamol was injected intraperitoneally in the rats of the 2nd and 4th groups at a concentration of 0.3 mg/kg twice a day for 2 weeks. The muscles were denervated using the crush method with pean. The animals were sacrificed 3, 6, 9, 12, and 14 days after treatment. Frozen cross-sections of soleus muscle were stained for myosin ATPase, pH 9.4. Cross-sectional area and percent of muscle fibers were analyzed morphometrically by computerized image analysis. Treatment with salbutamol induced hypertrophy of all fiber types and a higher percentage of type II fibers (21 percent) in the healthy rat soleus muscle. Denervation caused marked atrophy of all fibers and conversion from type I to type II muscle fibers. Denervated muscles treated with salbutamol showed a significantly larger cross-sectional area of type I muscle fibers, 28.2 percent compared to the denervated untreated muscle. Moreover, the number of type I fibers was increased. These results indicate that administration of salbutamol is able to induce changes in cross-sectional area and fiber type distribution in the early phase of treatment. Since denervation-induced atrophy and conversion from type I to type II fibers were improved by salbutamol treatment we propose that salbutamol, like other ß2 adrenoceptor agonists, may have a therapeutic potential in improving the condition of skeletal muscle after denervation.

Effect of salbutamol on innervated and denervated rat soleus muscle.

The objective of the present investigation was to perform a 14-day time-course study of treatment with salbutamol, a beta2 adrenoceptor agonist, on rat soleus muscle in order to assess fiber type selectivity in the hypertrophic response and fiber type composition. Male Wistar rats were divided into four groups: control (N = 10), treated with salbutamol (N = 30), denervated (N = 30), and treated with salbutamol after denervation (N = 30). Salbutamol was injected intraperitoneally in the rats of the 2nd and 4th groups at a concentration of 0.3 mg/kg twice a day for 2 weeks. The muscles were denervated using the crush method with pean. The animals were sacrificed 3, 6, 9, 12, and 14 days after treatment. Frozen cross-sections of soleus muscle were stained for myosin ATPase, pH 9.4. Cross-sectional area and percent of muscle fibers were analyzed morphometrically by computerized image analysis. Treatment with salbutamol induced hypertrophy of all fiber types and a higher percentage of type II fibers (21%) in the healthy rat soleus muscle. Denervation caused marked atrophy of all fibers and conversion from type I to type II muscle fibers. Denervated muscles treated with salbutamol showed a significantly larger cross-sectional area of type I muscle fibers, 28.2% compared to the denervated untreated muscle. Moreover, the number of type I fibers was increased. These results indicate that administration of salbutamol is able to induce changes in cross-sectional area and fiber type distribution in the early phase of treatment. Since denervation-induced atrophy and conversion from type I to type II fibers were improved by salbutamol treatment we propose that salbutamol, like other beta2 adrenoceptor agonists, may have a therapeutic potential in improving the condition of skeletal muscle after denervation.

Age-related skeletal muscle atrophy in humans: an immunohistochemical and morphometric study.

The aim of this study was to determine age-related changes in three human muscles with different function and location in the body. The cross sectional area and the percentage of fibers type I, type IIA and type IIX were studied in vastus lateralis, deltoideus and external intercostal muscle. Muscle samples were obtained from 30 male subjects, aged 20-80 years. Fiber types were defined immunohistochemically, using monoclonal antibodies specific for type I, type IIA and type IIX fibers. Cross sectional area of muscle fibers was analyzed morphometrically by computerized image analysis. All muscle fiber types (I, IIA, IIX) showed the reduction in the fiber size in all three examined muscles. In all muscles the proportion of type I and type IIA was changed, but not in type IIX. With increasing age results showed the increase in proportion of type I, while proportion of type IIA fibers decreased, with vastus lateralis muscle being the most affected. These results suggest that age-related muscle atrophy is not a general phenomenon, and does not affect all muscles equally.

Muscle fiber type composition and morphometric properties of denervated rat extensor digitorum longus muscle.

AIM: Analysis of fiber type composition and fiber size of extensor digitorum longus (EDL) muscle in rats during 30 days of denervation. METHODS: Fiber types were defined immunohistochemically using monoclonal antibodies specific for slow (type I) and fast fibers (type IIA, IIX, and IIB). Antibodies were applied on transverse sections of denervated extensor digitorum longus muscles 6, 12, and 30 days after denervation. Cross sectional area of muscle fibers was analyzed morphometrically by computerized image analysis. RESULTS: Control EDL muscle was composed of 41% of type IIB, 32% of IIA, 23% of IIX, and 4% of type I muscle fibers. The most profound effect of denervation was observed 30 days after the transection of the sciatic nerve. Denervation decreased the percentage of both type IIB and type IIX muscle fibers to 36% and 13% of the control muscle, respectively (p?0.001 for both), and increased the percentage of types IIA and type I muscle fibers to 42% and 9% of the control, respectively (p<0.001 for both). Morphometric analysis revealed progressive atrophy of all fast muscle fibers, which started 6 days after denervation (p<0.001). Thirty days after the sciatic nerve transection, a strong reduction in fiber size of type IIA, IIX, and IIB muscle fibers was observed (p<0.001 for each type). Type I muscle fibers initially showed the reduction in fiber size (p<0.001) but regained the size of control fibers until day 30. CONCLUSION: Denervation decreased the percentage of type IIX and IIB muscle fibers, with concomitant increase in type IIA and type I muscle fibers. The reduction in fiber size was observed in type IIA, IIX, and IIB muscle fibers.

Muscle fiber type distribution in multifidus muscle in cases of lumbar disc herniation.

A study was conducted to analyze the distribution and diameter of muscle fiber types in samples of the medial paravertebral lumbar muscle, i.e., multifidus muscle, obtained from 76 patients who underwent surgery for disc herniation. The samples were compared with 41 control samples of corresponding muscle tissue taken from 41 young healthy subjects who had died a sudden death. Histochemical analysis of fibers associated with myofibrillar adenosine triphosphatase (ATPase) revealed the presence of Type I fibers (slow-twitch fibers) and of Type IIA and IIB fibers (fast-twitch fibers) in both the experimental and control samples. The respective percentage of muscle fibers was calculated and their diameters were measured. Type I fibers predominated in both groups and were significantly larger in diameter than Type IIA and IIB fibers. Both fast-twitch fiber types were distributed in almost equal proportions in the healthy women. In the healthy men, Type IIA fibers prevailed. In the healthy females, the percentage of Type I fibers was found to be slightly higher than in the males, but the diameter of all fiber types was respectively smaller. In the females who had undergone surgery, Type I fibers were significantly larger in diameter than those of the healthy subjects. On the other hand, the diameters of all muscle fiber types were significantly larger, and the percentage of both fast-twitch fibers were Idwer in the samples from men who underwent surgery, as compared to the healthy tissue samples. The morphometric changes in the multifidus muscle at the level of the protruded disc observed by the histochemical method for demonstration of myofibrillar ATPase could not be related to the compressed nerve root in the majority of cases in our study.

Trichloroethene and tetrachloroethene in ground waters of Zagreb, Croatia.

At the end of 1986 the presence of chlorinated hydrocarbons was detected in the ground water of the industrial area of Zagreb, Croatia. Concentrations of trichloroethene and tetrachloroethene were close to or exceeded maximum admissible concentrations prescribed by the Public Health Regulations for drinking water (30 micrograms/l for trichloroethene and 10 micrograms/l for tetrachloroethene). The pumping-site situated within the area had been temporarily closed until a water-treatment plant based upon adsorption on activated carbon was built. Analysis of the results of adsorption of the investigated chlorinated hydrocarbons on activated carbon in granules confirmed a remarkably better adsorption of tetrachloroethene compared to trichloroethene. By constant monitoring and replacing of saturated carbon at the appropriate time, the concentrations of trichloroethene and tetrachloroethene in drinking water consumed by approx. 20% of the city population never exceeded maximum admissible concentrations in the course of 10 years.

Cloning and characterization of a 70 kd heat shock cognate (hsc70) gene from the zebrafish (Danio rerio).

The heat shock 70 family of proteins is one of the most highly conserved among all species. The genes encoding these proteins have been cloned and sequenced from bacterial species to humans with a high degree of homology preserved throughout evolution. Here we describe the cloning and characterization of a cDNA encoding a 70 kd heat shock cognate (hsc70) gene from the zebrafish (Danio rerio). A high degree of conservation is observed among hsc70 genes of other species as shown by phylogenetic analysis. The characterization of a hsc70 gene in the zebrafish provides a marker for studying the role of a constitutively expressed member of the hsp70 family in an important developmental and evolutionary model system.

The mechanism of angioplasty--endoscopic and morphometric investigations in an experimental model.

The effect of angioplasty using two different sizes of balloon catheter were examined by angiography and angioscopy before and after dilatation. A significant increase in the outer and inner diameters was seen accompanied by a decrease in the cross sectional area of the stenoses as well as the thickness of the vascular wall. Angioscopy revealed typical longitudinal tears of the plaque edges which are pressed during flow against the vessel wall. Turbidity of saline could be seen after dilatation indicating possible rupture of the atheromatous plaque. These findings are discussed in the light of the mechanisms of angioplasty and the possible reasons for the good early and long-term results.

Selection and preoperative treatment of over-seventy-year-old patients undergoing thoracotomy.

The thoracic surgeon is confronted with the question of the operability of patients over 70 years old more and more frequently. Not only the advanced age, but also probable functional impairments are decisive for the outcome of an operation in this often polymorbid age group. Fifty-three patients over 70 years old underwent 58 thoracotomies. The hospital lethality was 7.5%, the complication rate 17%. These results could be obtained by a specific selection of patients, based on functional parameters, intensive preoperative medical and physiotherapeutic treatment in terms of improvement of possible functional deficits and the usual postoperative intensive care. In our long-term observations we could record a 5-year survival rate of 100% in patients with benign diseases and of 46% in cases of bronchial carcinoma. These results confirm our attitude that the age 70 years and older should not be considered as contraindication for thoracic surgery.

Functional surgery of bullous emphysema.

Multiple large and small emphysematous bullae were resected in 27 patients with chronic obstructive lung disease (COLD). Twenty-two patients were operated on one side, and 5 patients underwent bilateral consecutive operations. Twenty-five patients were male, 2 female, and they were between 22 and 67 years old (mean 49.5 years). All patients had a follow-up examination between 3 and 48 months postoperatively. As operative techniques, resection by means of a clamp, plication of cysts according to Nissen, resection with homologous dura plasty (7 patients) and pericardial plasty (7 patients) were used. In 19 patients preoperative and postoperative pulmonary function was compared. Functional improvement occurred in 17 patients - including all of the 5 bilateral procedures. Postoperative improvement was more pronounced with decreasing preoperative pulmonary function, measured as VC, RV, IGV and Raw. Partial pulmonary insufficiency could be improved in 9 patients and global pulmonary insufficiency was improved in 5. In 16 cases physical work capacity was increased. The hemodynamics of the pulmonary circulation were improved in all patients with increased preoperative pulmonary artery pressure (latent pulmonary hypertension in 7 patients, overt pulmonary hypertension in 5). FEV1 was least influenced by surgery, especially in patients more than 50 years old. The long-term prognosis, thus has to be judged cautiously. One patient died postoperatively (mortality 4%). The technique of dura and pericardial plasty, aiming at functional adaptation, is described. Sutures inverting or folding pulmonary tissue are avoided. The aspect of at least temporary (up to 3 years) functional improvement leads us to advocate the use of extended criteria of operability.

[Long-term results following resection and esophageal reconstruction in esophageal cancer]. / Langzeit-Ergebnisse nach Resektion und Speisewegsrekonstruktion beim Oesophaguscarcinom.

Between 1968 and end of 1981 162 patients, aged 30 to 77 years (mean 59,9 years) underwent esophageal resection and digestive tract reconstruction for carcinoma of the esophagus and cardia. There were 102 squamous cell- and 60 adenocarcinomas which were located in 8 patients in the upper thoracic third, in 67 patients in the middle third and in 87 patients in the lower thoracic third including the cardia. Esophago-gastrostomy was performed in 138 cases whereas colon was used in 18 and jejunum in 6 cases. Overall hospital mortality was 14.8% and was reduced to 9.4% during the period from 1976 to 1981. Survival rates at two years and 5 years were 31.8% and 5.6% resp. However, for patients with seemingly "curative" resections, i.e. when the carcinoma was limited to the esophageal wall and the lymph nodes were found uninvolved, these rates were 73.2% and 23.7% resp. Follow-up studies in 103 patients revealed typical functional sequelae such as anastomotic stenosis and reflux in less than 20% of the patients. The incidence of such symptoms was higher in patients with a low subhilar anastomosis than in patients with a high supraaortic anastomosis. It is concluded that esophageal resection and reconstruction of intestinal passage for carcinoma may significantly prolong survival and may warrant a fairly acceptable quality of life. More than 70% of the investigated long-term survivors were leading a normal life also resuming an improved nutritional status.

[Use of the TDMAC heparin shunt for operations on the descending thoracic aorta (author's transl)]. / Der Gebrauch des TDMAC-Heparin-Shunts bei Operationen an der Aorta descendens.

This report summarizes our experience with the TDMAC heparin shunt for aortic bypass in descending thoracic aortic surgery. Between 1977 and 1981 twenty-four operations were performed with this shunt (19 men, 4 women, mean age 42 age). Indications for surgery were acute traumatic aortic rupture (6 patients), chronic aortic rupture (6 patients), acute aortic dissection (1 patient), chronic aortic dissection (4 patients), atherosclerotic aneurysms (3 patients), aortic aneurysms combined with PDA (1 patient), aortic aneurysm secondary to coarctation repair (1 patient), and infection of a vascular prosthesis (1 patient). Four patients died (hospital mortality 16.7%). One patient suffered perioperative paraplegia. In this patient the small size (7 mm) shunt hat been used. Therefore we suggest the large bore (9 mm) shunt be applied whenever possible, since even this larger size device displays a significant pressure gradient. When insertion of the shunt into the left subclavian artery is difficult, the ascending aorta or the apex of the left ventricle may be cannulated instead. In our cases we did not encounter any complications arising from shunt cannulation. The advantages of the TDMAC heparin shunt focus on the reduction of bleeding complications more common under systemic heparinization, and on less pronounced hemodynamic and metabolic sequelae following aortic clamping and declamping. With this shunt nearly all possible ischemic organ damage can be avoided.

Surgery for traumatic rupture of the thoracic aorta.

Between 1975 and 1980, 9 patients with traumatic rupture of the thoracic aorta were operated at our institution. All patients showed additional multiple limb and internal organ injuries. Leading symptoms of aortic rupture were mediastinal widening (8), left-sided hemothorax (6), and acute aortic coarctation (2). Aortic rupture was proven by angiography in 8 patients and during exploratory thoracotomy in another. The time interval between trauma and operation was one to 48 hours, in 6 patients less than 4 hours. Atrio-femoral bypass was used in 3 patients, TDMAC-heparin shunt in 4 patients and 2 patients were operated without bypass. Prosthesis interposition was required in 3 patients while direct suture was possible in 6 patients. Long-term survival was achieved in 7 patients, one patient died from shock sequelae and another had suffered inoperable multiple rupture along the ascending and transverse aorta. It is concluded that patients with traumatic aortic rupture have a relatively good prognosis if diagnosis is established immediately and if surgery is feasible. The operative result is influenced substantially by the degree of preoperative shock and the presence of additional injuries.

Thymolipoma--a rare, benign tumor of the thymus gland two case reports and review of the literature.

Two case reports of thymolipoma are presented. In a review of the literature on the subject, the clinical and etiologic features of this nonmalignant tumor in the anterior mediastinum are discussed. Although rare, thymolipoma should be considered in the differential diagnosis of mediastinal tumors.

Funnel chest correction by use of AO implants and instruments.

A new method for funnel chest correction using AO implants and instruments is described. The method appears to offer certain advantages particularly in the more rigid chest wall of aldolescents and adults.

[Left ventricular dynamics with exercise after revascularization in advanced coronary heart disease (author's transl)]. / Linksventrikuläre Belastungsreaktion nach Revaskularisierung bei fortgeschrittener koronarer Herzkrankheit.

66 patients with 2 and 3 vessel coronary heart disease were studied before and after complete successful revascularization. Hemodynamic measurements and biplane left ventricular angiograms were obtained at rest and during supine bicycle exercise.--After operation a significant overall decrease of LVEDP with exercise was seen; exercise LVEF increased in cases with left main disease and in most cases with double vessel disease and double bypass. Inconsistant response was present in 3 vessel disease. Improvement of left ventricular dynamics with exercise in advanced coronary disease after complete revascularization can be expected mainly in 2 vessel disease and left main coronary disease.