Engineering a powerful green cell factory for robust photoautotrophic diterpenoid production

Diterpenoids display a large and structurally diverse class of natural compounds mainly found as specialized plant metabolites. Due to their diverse biological functions they represent an essential source for various industrially relevant applications as biopharmaceuticals, nutraceuticals, and fragrances. However, commercial production utilizing their native hosts is inhibited by low abundances, limited cultivability, and challenging extraction, while the precise stereochemistry displays a particular challenge for chemical synthesis. Due to a high carbon flux through their native 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway towards photosynthetically active pigments, green microalgae hold great potential as efficient and sustainable heterologous chassis for sustainable biosynthesis of plant-derived diterpenoids. In this study, innovative synthetic biology and efficient metabolic engineering strategies were systematically combined to re-direct the metabolic flux through the MEP pathway for efficient heterologous diterpenoid synthesis in C. reinhardtii. Engineering of the 1-Deoxy-D-xylulose 5-phosphate synthase (DXS) as the main rate-limiting enzyme of the MEP pathway and overexpression of diterpene synthase fusion proteins increased the production of high-value diterpenoids. Applying fully photoautotrophic high cell density cultivations demonstrate potent and sustainable production of the high-value diterpenoid sclareol up to 656 mg L^-1 with a maximal productivity of 78 mg L^-1 day^-1 in a 2.5 L scale photobioreactor, which is comparable to sclareol titers reached by highly engineered yeast. Consequently, this work represents a breakthrough in establishing a powerful phototrophic green cell factory for the competetive use in industrial biotechnology.

Traumatic rupture of the gallbladder after blunt abdominal trauma

The extremely rare case of 83-year old woman with rupture of the gallbladder due to blunt abdominal trauma is presented. Patient's general condition was complicated because of coagulopathy caused by oral anticoagulant what has contributed to intra-abdominal haemorrhage. The rupture of the gallbladder and rupture of the liver were found during operation. The diagnosis of rupture of the gallbladder due to blunt abdominal trauma is difficult to establish before exploration and often coexists with injury to the liver. The treatment of choice in rupture of the gallbladder is cholecystectomy. In patients after abdominal trauma, beside damage of parenchymatous organs, the injury to other organs should be taken into consideration, even if they occur very rarely.

The diagnosis and surgical management of diseases of the adrenal glands

The authors present their own experience in the diagnosis and management of adrenal tumours and cysts. During the years 1980-2000, 74 patients were underwent surgical treatment. Of this group, 23 had Cushing's syndrome, 19 phaeochromocytomas, 4 Conn's syndrome, 2 virilising tumours, 2 adenocarcinomas, 2 ganglioneuromas, 7 adrenal cysts, 8 adenomas, 3 adenocortical carcinomas, 2 nodular hypertrophies, 1 myelolipoma and 1 liposarcoma. Treatment was effective in 73 (98.6%) of patients. We recommend the transperitoneal approach which allows the visual evaluation of both adrenals and extra adrenal tissue. We regard surgical intervention as being the only effective method of treating adrenal tumours.

Epithelial anomalies in chronic pancreatitis as a risk factor of pancreatic cancer

BACKGROUND/AIMS

The relationship between chronic pancreatitis and the development of pancreatic cancer is still a matter of dispute. Our aim was to determine the frequency of hyperplastic, metaplastic and dysplastic epithelial anomalies in the course of chronic pancreatitis and the potential steps in their development to malignancy.

METHODOLOGY

The study was based on biopsy material of 70 patients with clinically diagnosed advanced chronic pancreatitis, who underwent partial or total pancreatectomy, as well as other operations. The patients were assigned to 2 groups: Group I (n = 41) with calcifying chronic pancreatitis; Group II (n = 29) with other forms of the disease. Histological sections were stained with hematoxylin-eosin, Mallory-azan, Gomori's silver method, and glycosaminoglycans (PAS and Alcian blue staining). Special interest was focused on the type and incidence of epithelial ductal and acinar cell anomalies, and on the degree of parenchymal scarring.

RESULTS

Hyperplasia of the ductal epithelium was present in 31.4%, focal squamous metaplasia in 21.4%, mucous metaplasia in 11.1%, cellular dysplasia in 8.6%, dysplastic acinar cell nodules in 21.4%, and "tubular complexes" in 30.0% of all cases. The differences in the frequency of these changes, except for ductal epithelial hyperplasia, were not statistically significant in two comparable groups. Advanced pancreatic fibrosis was associated with epithelial anomalies in 65.7% of all cases.

CONCLUSIONS

From the morphological point of view, the adequate prerequisites for the consideration of advanced forms of chronic pancreatitis, independent of type, as a risk factor of pancreatic cancer exist, necessitating the surgical removal of pathological lesions.

[Results of surgical treatment for adrenal gland diseases]

The authors present their own experience in diagnosing and surgical treatment of adrenal tumors. The group consisted of 52 patients with adrenal tumors treated surgically in our Department in 1980-1996. There were 37 women (71%) and 15 men (29%); 22 with Cushing syndrome, 14 with pheochromocytoma, 4 with Conn's syndrome, 1 with virilizing tumor, 1 with adenocarcinoma, 1 with adrenocortical carcinoma, 1 with ganglioneuroblastoma 2 with adenomas, 6 with adrenal cyst. Diagnosis pre- and intraoperative was verified with histological examination. We suggest that the ultrasonography and computed tomography are the most useful methods in determining of tumor localisation. The authors prefer intraperitoneal approach, enabling evaluation of the contralateral adrenal gland and possible localisation of extraadrenal foci. Good results were obtained in 51 patients (98%).

[The influence of hydrocortisone and dopamine on the behavior of fibrils and values of some sympathetic mediators in kidneys of experimental endotoxic shock]

The aim of the study was to evaluate the influence of hydrocortisone (H) and dopamine (DA) on behaviour of tissue content of DA, NA and homovanillic acid (HVA) as well as adrenergic fibers (AF) in canine kidney during endotoxic shock (ES). Above changes were considered on the background of hemodynamic, biochemical and morphologic alterations. Investigations were carried out on 5 groups of animals: I-control, II-dogs in ES without treatment, III-dogs in ES treated with H, IV-ES treated with DA, V-animals treated with H and DA. It was shown that the amount of catecholamines add AF in group II was lower than in group I. In groups of animal treated we observed bigger of well preserved AF and catecholamines, and the image similar to the one observed in control group-I was observed in group V. It appears from the study conducted that AF show active role to the course of ES, and beneficial effect of the treatment applied can be results of its influence on the function of DA, NA and AF.