In vivo rAAV-mediated human TGF-β overexpression reduces perifocal osteoarthritis and improves osteochondral repair in a large animal model at one year

OBJECTIVE

Osteoarthritis (OA) is a serious consequence of focal osteochondral defects. Gene transfer of human transforming growth factor beta (hTGF-β) with recombinant adeno-associated virus (rAAV) vectors offers a strategy to improve osteochondral repair. However, the long-term in vivo effects of such rAAV-mediated TGF-β overexpression including its potential benefits on OA development remain unknown.

METHOD

Focal osteochondral defects in minipig knees received rAAV-lacZ (control) or rAAV-hTGF-β in vivo. After one year, osteochondral repair and perifocal OA were visualized using validated macroscopic scoring, ultra-high-field MRI at 9.4 T, and micro-CT. A quantitative estimation of the cellular densities and a validated semi-quantitative scoring of histological and immunohistological parameters completed the analysis of microarchitectural parameters.

RESULTS

Direct rAAV-hTGF-β application induced and maintained significantly improved defect filling and safranin O staining intensity and overall cartilage repair at one year in vivo. In addition, rAAV-hTGF-β led to significantly higher chondrocyte densities within the cartilaginous repair tissue without affecting chondrocyte hypertrophy and minimized subarticular trabecular separation. Of note, rAAV-hTGF-β significantly improved the adjacent cartilage structure and chondrocyte density and reduced overall perifocal OA development after one year in vivo.

CONCLUSIONS

rAAV-hTGF-β treatment improves long-term osteochondral repair and delays the progression of perifocal OA in a translational model. These findings have considerable potential for targeted molecular approaches to treat focal osteochondral defects.

Role of polyamines in plant growth regulation of Rht wheat mutants

Besides their protective role, polyamines also serve as signalling molecules. However, further studies are needed to elucidate the polyamine signalling pathways, especially to identify polyamine-regulated mechanisms and their connections with other regulatory molecules. Reduced height (Rht) genes in wheat are often used in breeding programs to increase harvest index. Some of these genes are encoding DELLA proteins playing role in gibberellic acid signalling. The aim of the present paper was to reveal how the mutations in Rht gene modify the polyamine-regulated processes in wheat. Wild type and two Rht mutant genotypes (Rht 1: semi-dwarf; Rht 3: dwarf mutants) were treated with polyamines. Polyamine treatments differently influenced the polyamine metabolism, the plant growth parameters and certain hormone levels (salicylic acid and abscisic acid) in these genotypes. The observed distinct metabolism of Rht 3 may more likely reflect more intensive polyamine exodus from putrescine to spermidine and spermine, and the catabolism of the higher polyamines. The lower root to shoot translocation of putrescine can contribute to the regulation of polyamine pool, which in turn may be responsible for the observed lack of growth inhibition in Rht 3 after spermidine and spermine treatments. Lower accumulation of salicylic acid and abscisic acid, plant hormones usually linked with growth inhibition, in leaves may also be responsible for the diminished negative effect of higher polyamines on the shoot growth parameters observed in Rht 3. These results provide an insight into the role of polyamines in plant growth regulation based on the investigation of gibberellin-insensitive Rht mutants.

Polyamines may influence phytochelatin synthesis during Cd stress in rice

Although the metabolism of phytochelatins and higher polyamines are linked with each other, the direct relationship between them under heavy metal stress has not yet been clarified. Two approaches were used to reveal the influence of polyamine content on cadmium stress responses, particularly with regard to phytochelatin synthesis: putrescine pre-treatment of rice plants followed by cadmium stress, and treatment with the putrescine synthesis inhibitor, 2-(difluoromethyl)ornithine combined with cadmium treatment. The results indicated that putrescine pre-treatment enhanced the adverse effect of cadmium, while the application of 2-(difluoromethyl)ornithine reduced it to a certain extent. These differences were associated with increased polyamine content, more intensive polyamine metabolism, but decreased thiol and phytochelatin contents. The gene expression level and enzyme activity of phytochelatin synthase also decreased in rice treated with putrescine prior to cadmium stress, compared to cadmium treatment alone. In contrast, the inhibition of putrescine synthesis during cadmium treatment resulted in higher gene expression level of phytochelatin synthase. The results suggest that polyamines may have a substantial influence on phytochelatin synthesis at several levels under cadmium stress in rice.

Alteration of sarcoplasmic reticulum Ca2+ ATPase expression in lower limb ischemia caused by atherosclerosis obliterans

Atherosclerosis is a disease caused by a build-up of fatty plaques and cholesterol in the arteries. The lumen of the vessels is obliterated resulting in restricted blood supply to tissues. In ischemic conditions, the cytosolic Ca²⁺ level of skeletal muscle may increase, indicating the alteration of Ca²⁺ removal mechanisms. Ca²⁺ is transported from cytosol into the sarcoplasmic reticulum by Ca²⁺ ATPase (SERCA), with its 1a isoform expressed in adult, while its 1b isoform in neonatal and regenerating fast-twitch skeletal muscle. To investigate the role of these isoforms in ischemic skeletal muscle, biopsies from musculus biceps femoris of patients who underwent amputation due to atherosclerosis were examined. Samples were removed from the visibly healthy and hypoxia-affected tissue. Significantly increased SERCA1a expression was detected under the ischemic conditions (246 ± 69%; p < 0.05) compared with the healthy tissue. Furthermore, the ratio of SERCA1a-positive fibers was slightly increased (46 ± 4% in healthy tissue and 60 ± 5% in ischemic tissue; p > 0.05), whereas SERCA2a did not change. In addition, in primary cultures derived from hypoxia-affected tissue, the diameter and fusion index of myotubes were significantly increased (30 ± 1.6 µm vs. 41 ± 2.4 µm and 31 ± 4% vs. 45 ± 3%; p < 0.05). We propose that the increased SERCA1a expression indicates the existence and location of compensating mechanisms in ischemic muscle.

[Surgical treatment of acquired, benign esophago-respiratory fistulas]

BACKGROUND

Acquired, benign esophago-respiratory fistula occurs as a rare complication of different disorders.

STUDY DESIGN

Over a period of 30 years, 37 patients with acquired, benign esophago-respiratory fistulas were treated at the authors' institutions. 35 of the 37 patients were operated upon. Acute operation involved primary repair of the trachea and esophagus, or intubation of the gullet and/or gastrostomy. Elective operations were performed on 13 patients.

RESULTS

Complications were observed in 14 patients. There were 4 cases with anastomotic leakage (all of them on the neck). Direct closure was carried out in 2 patients; the remaining 2 cases healed spontaneously. None of the 4 patients died. Seven of the 37 patients died (18.9%). This seems acceptable in view of the severity of the cases and the extension of the operations.

CONCLUSIONS

1. The causes of a majority of the esophago-respiratory fistulas in this material are connected with the complications of corrosive injury and peptic stricture of the esophagus. 2. The well-known fact that most of these fistulas occur in the right chest is confirmed. 3. Gastrostomy and/or intubation of the gullet seems to be the best solution for this lesion in the acute cases and in severely ill patients. 4. In elective cases, reconstruction is suggested, if possible in one step.

[Surgical treatment of Boerhaave's syndrome]

The authors treated four patients with spontaneous oesophageal rupture between 1995 and 1999. The interval from injury to surgical treatment was less than 24 h in two cases, and longer than 24 h in the other two cases. The surgical treatment was primary closure of the rupture and mediastinal drainage with gastrostomy within 24 h after the onset. Septic complications occurred in lately presented patients. In these cases, the surgical treatment consisted of oesophagectomy, mediastinal drainage and feeding gastrostomy. The alimentary tract was reconstructed with interposed ileocolon eight weeks later. Each patients was fully recovered. The authors underline the importance of early diagnosis which obviously determine the prognosis and the choice of surgical treatment. Primary repair is proposed after early diagnosis, however oesophageal resection is recommended 24 h after the injury.

Lipoma of the liver: a differential-diagnostic problem

BACKGROUND AND AIMS

Lipomatous tumors of the liver are extremely rare; most of them are found incidentally at autopsy. Appropriate methods of the diagnosis of these lesions are ultrasonography (US), computed tomography (CT) and biopsy.

CASE REPORT

The case of a 65-year-old man who had undergone an upper-rectum resection because of exulcerated adenocarcinoma of the rectum is described. Six months later, routine control examination revealed a solid tumor in the left lobe of the liver. The tumor was not demonstrated by either sonography or CT before the operation. Repeated US, CT scan and fine-needle biopsy could not exclude the possibility of a metastatic tumor secondary to previous malignancy. The lesion was removed by wedge resection and was proven to be a lipoma.

CONCLUSION

Despite adequate preoperative examination (CT, biopsy and US), an anamnestic adenocarcinoma of the rectum can lead to inappropriate therapy. The inadequate result of our therapeutic policy can be explained by the extremely rare incidence of lipoma of the liver.

[Esophago-pericardial fistula caused by recurrent esophageal tumor]

The esophago-pericardial fistula is a rare disease that causes a rather high mortality. Up to now less than 70 cases were published in the literature. The authors report an esophago-pericardial fistula caused by recurrent esophageal tumor one year after resection in the lower third esophagus for esophageal cancer. With conservative treatment the patient was kept alive for a month. No case report can be found in the literature of an esophago-pericardial fistula of the same etiology.

[Drug therapy of gastroesophageal reflux (a prospective controlled clinical trial)]

One year follow up(1.5, 3, 6, 12 months) study was established to examine the role of several classes of drugs in the treatment of reflux disease in 40 patients on the basis of objective control parameters (pH-metry, endoscopy, histology). The therapy was initiated, respectively, the different stage of severity (Savary-Miller): in stage 0 sucralfate + domperidone, in stage I and II: ranitidine + domperidone and in stage III-IV omeprazole was introduced. Our results proved that sucralfate + domperidone is curative on reflux oesophagitis in stage 0 cases. In stage I sucralfate and domperidone were effective in 3 of 9 cases, ranitidine + domperidone was optimal in 5 of 9, and omeprazole was required in 1 of 9 patients. In stage II, ranitidine + domperidone was effective only in 4 of 11 patients, and the initial therapy was modified to omeprazole in 7 of 11 patients to find the optimal drug in this stage. In stage III and IV only omeprazole showed curative effect and the doses required were 20 mg in 8 of 13 and 40 mg in 5 of 13 patients. The complaints improved in 34 of 40 patients after 6 weeks treatment, while histological healing of reflux oesophagitis was observed in 12 of 40 cases. After 3 months the endoscopic healing rate was 28/40, but histological healing could be reached after 6 months of optimal treatment in 30 of 40 cases. We can conclude, that the optimal drug selection may result a rapid improvement of complaints, but endoscopic and histological regeneration of the oesophageal mucosa is more graduated with time. The healing process of the reflux oesophagitis requires 3 months. Proton pump inhibitor drugs have an enhanced role in the treatment of gastrooesophageal reflux disease, and our results proved that the efficient and safety treatment of mild form (stage II) of disease requires the administration of proton pump inhibitors.

Pharyngeal dysphagia caused by isolated myogen dystrophy of musculus cricopharyngeus

Five patients suffering from idiopathic cricopharyngeal dysfunction (without Zenker's diverticulum) were treated surgically. Together with cricopharyngeomyotomy biopsies were taken at the level of the cricopharyngeus. Histological, enzyme hystochemical and electronmicroscopic examinations were performed on all patients. In two cases the histology revealed myogen dystrophy (presence of necrosis, myophagocytosis, abnormal fiber structure, basophilic fibers, fibrosis, mild cellular reaction and predominancy of fiber type I). Since the complete patient evaluation (clinical features, electromyography, serum creatinin phosphokinase level, etc.) could rule out any general, muscle disorders, the cause of the idiopathic pharyngeal dysfunction must have been in these two cases an isolated myogen dystrophy of the cricopharyngeus.

[Evaluation of complaints and diagnostic methods, considered to be objective, in gastroesophageal reflux]

Authors analyse complaints of 166 patients suffering in gastroesophageal reflux disease, and results of different objective diagnostic methods (X-ray swallowing, endoscopy, 24 hour pH-monitoring, esophageal manometry). The degree of severity of typical complaints and changes found by diagnostic procedures were scored. Individual diagnostic proceduresindicated the characteristic changes of gastroesophageal reflux with great deviations. Hiatal hernia identified by x-ray, esophagitis observed by endoscopy, abnormal reflux revealed by pH-metry together occurred only at 36% of patients. Significant correlation could be revealed only between the degree of changes found by x-ray or pH-metry--applying them one by one--and the complaints of the patients, but with the combination of four diagnostic methods a tight, positive correlation could be demonstrated with the severity of the complaints of the patients in every case. Applying of diagnostic methods as much as possible completing each others, with consideration to the complaints of the patients is suggested for having the diagnosis been precise of the gastroesophageal reflux disease, and for measuring of efficacy of treatment. The importance of tight collaboration of internist, radiologist and surgeon and the significance of complex examination is underlined.

The inhibitory effects of allopurinol on the production and cytotoxicity of tumor necrosis factor

Allopurinol, a xanthine oxidase inhibitor, impaired the cytotoxic effect of human recombinant tumor necrosis factor (TNF) against WEHI cells. Actinomycin D abolished the inhibition of cytotoxicity by allopurinol. Allopurinol also exerted an inhibitory effect on the production of TNF by human mononuclear cells stimulated by either heat-killed Staphylococcus aureus or E. coli lipopolysaccharide. It is suggested that allopurinol inhibits TNF cytotoxicity by decreasing the level of oxygen free radicals generated (among other mechanisms) by the action of xanthine oxidase. Whatever the mechanism, the fact that allopurinol counteracts the toxicity of TNF can help towards an understanding of the complex nature of TNF toxicity.

[Radioisotope study of esophageal transit]

Diagnostics relating to esophageal motility disorders has come into the focus of attention in recent years. A review is made of the possibilities of application of radioisotope esophageal transit measurement. The methods employed and the models of data recording and processing in this field are listed. The value of this procedure in different esophageal disorders is discussed in detail. Two characteristic cases are reported to illustrate the method. It is concluded that measurement of the radionuclide esophageal transit is a noninvasive, simple and safe technique for the screening of esophageal motility dysfunction.

[Endoscopic and surgical removal of foreign bodies from the upper gastrointestinal tract]

Results of management of 67 patients who swallowed foreign bodies are discussed. Types of foreign bodies, the importance of previous esophageal strictures, the rare diagnostic difficulties and the different clinical signs are analyzed. Authors stress that the most frequent causes of the artificial esophageal perforation are the endoscopic removal of swallowed foreign bodies. A surgical intervention in 14 cases was necessary. Three patients were lost after the surgical intervention.

[Esophageal dilatation using the Savary-Gilliard sound set]

Authors present a method of esophageal dilatation and report their experiences. The place of esophageal dilatation among other therapeutic approaches of esophageal stricture is discussed. The advantage of Savary-Gilliard bougies and guide wire and its applications are presented. During one and a half year 218 esophageal dilatations were performed at 82 patients. 11 patients were intubated endoscopically. Esophageal perforation occurred in 2 cases (0.93%). Dilatation of the esophagus with Savary-Gilliard bougies and using of the guide wire are considered a safe and many-sided method in the diagnosis and treatment of esophageal strictures.

[Barrett esophagus]

There are a lot of contradiction and uncertainty related to Barrett's esophagus. Authors review the literature about the incidence, the aetiology, the pathology of the ailment, the possibility of diagnosis and treatment. 25 Barrett's esophagus were observed in the course of controlling of patients after antireflux operations and investigations of patients suffering from gastroesophageal reflux disease. X-ray examination, endoscopy, biopsy, 24-hour pH monitoring of the distal esophagus and esophageal manometry were performed. Because of the possibility of malignant transformation Barrett's esophagus requires yearly endoscopic surveillance and biopsy at least. Antireflux procedure does not protect against the development of adenocarcinoma.

[Can gastroesophageal reflux be prevented by inducing a scar tissue ring around the cardia?]

Severe gastroesophageal reflux was accomplished in 18 dogs by circular cardiomyectomy. After this intervention a Vicryl scarf was placed around the cardia in 12 dogs. The Vicryl scarf was absorbed within 6 months and in its place remained a scarred tissue. In the follow up gastroesophageal reflux could not be detected by manometry, pH-metry, radiology and endoscopy. In the control group all 6 dogs died within 3 weeks due to complications of gastroesophageal reflux. On the basis of these data the Vicryl scarf implantation is an effective, simple, new antireflux operation which can be initiated into the human surgical practice.

[Emergency treatment of corrosive gastrointestinal injuries]

Authors discuss their experience of management for caustic gastrointestinal injury. Importance of urgent endoscopy in establishing the extend of injury is emphasized. In eight out of 12 surgical intervention an esophagogastrectomy were performed. According to their experience in case of serious caustic burn the only hope to save the patients life is the early radical operation.

[Early cancer of the esophagus]

The authors report four cases with the postoperative diagnosis of the early cancer of the esophagus. The histological type of the tumor was squamous cell carcinoma in three cases and adenocarcinoma in the remaining one. The tumors were localized in the lower part of the esophagus. Left sided thoraco-laparotomy was carried out in two cases. They used a right sided thoracotomy with abdominal and neck incisions. Trans-mediastinal esophagectomy was performed in the remaining one case. The continuity of the gastrointestinal tract was restored by substernal colon interposition in a case, by substernal stomach in another one and by oesophago-jejunostomy in the remaining two cases. New diagnostic possibilities and the international results of the treatment of the early esophageal cancer are discussed.

Emergency esophagogastrectomy for treatment of hydrochloric acid injury

Eight patients with severe hydrochloric acid injury of the esophagus and stomach had early esophagogastrectomy. Four patients survived and 6 to 8 weeks later underwent successful substernal colon replacement. The value of early diagnosis and subsequent aggressive surgical management of patients who have ingested hydrochloric acid is stressed.

[Surgical treatment of stomach cancer with extended removal of lymph nodes]

The authors evaluate the results of extensive lymph node dissection for gastric cancer at 50 patients. It has been found that the lymph node dissection did not increase the risk of operation. The mortality rate was 2%. The average number of removed and histologically examined lymph nodes was 26. The extensive lymph node dissection and the accurate histology provided opportunity for precise staging. Their first evaluation of survival showed an encouraging improvement of prognosis regard to that of patients survival treated by traditional surgical method. Besides it they reviewed the classification of Japanese Research Society for Gastric Cancer for the lymph drainage of the stomach and the surgical technique of the lymph node dissection.

[Reconstruction of the oral and pharyngeal mucosa by a microsurgical method using a jejunal graft]

The microsurgery is a new, modern method of the reconstructive surgery which has made the free transplantation of the jejunal graft possible. The jejunum transplanted with microvascular anastomosis lends itself mainly to replacing the segmental and concentrical defect of the initial part of the alimentary tract, but the splitted jejunal graft cut along the antimesenterical side, because of its favourable biological nature, can be used for reconstruction of the oral and pharyngeal mucosus membrane. The authors applied the splitted jejunal graft in four cases for the reconstruction of oropharyngeal defects due to excision of malignant tumours. In harmony with literary data good result is reported on.

[Cricopharyngeal achalasia caused by isolated muscular dystrophy]

The authors--in connection with two surgically successful treated cases--discuss the diagnosis and the surgical treatment of the cricopharyngeal achalasia. By means of histological methods it was verified that in the background of this disease stads an isolated muscle dystrophy localized to the upper esophageal sphincter.

[Management of injuries of the artificial esophagus]

The authors analyse their experiences in connection with 20 cases of artificial esophageal injuries. Attention is called to the intraoperative lesions of the esophageal wall and to the damages caused by drugs. They underline the importance of the time factor and good results were achieved by using so called "conservative surgical treatment".

Polyribosomes in protoplasts isolated from tobacco leaves

Polyribosomes (polysomes), active in an amino acid incorporation system in vitro, were isolated from tobacco leaf protoplasts. A comparison of polysome profiles indicated that the polysome/monosome ratio is greatly decreased in isolated protoplasts as compared to the intact leaf. In isolated protoplasts, a marked accumulation of ribosomal subunits was also found. The division of protoplasts, as investigated in the 8-cell and callus stages, was associated with a(n) (at least) partial regeneration of polysome profiles characteristic for leaves. Plasmolysis of leaves attached to the plant had no great effect on the polysome profile. However, leaf excision per se resulted in a dramatic loss of polysomes, even when the leaf tissue was floated on water. It is concluded that the isolation of the cell from its normal environment, and not the osmotic stress and associated increase in RNase activity, is the most important factor responsible for the loss of polysomes in isolated protoplasts.

Effect of "osmotic stress" on protein and nucleic acid synthesis in isolated tobacco protoplasts

The incorporation of labeled precursors into RNAs and proteins of isolated tobacco (Nicotiana tabacum L.) leaf protoplasts decreases with increasing osmotic pressure in the incubation medium. The incorporation of precursors into RNA and proteins is linear for 15-18 h after the isolation of the protoplasts, irrespective of the osmolarity of the culture media. The uptake of precursors is also affected by the osmolarity of the medium. However, the osmotic stress-induced inhibition of incorporation of precursors into RNA and proteins is also apparent if the differences in uptake are taken into consideration in the calculation. Incorporation of (32)P into TMV-RNA is also inhibited by osmotic stress. As assayed by the double labeling ratio technique, osmotic stress has less unequivocal effect on TMV protein synthesis.