Angiogenesis in glioblastoma: Molecular and cellular mechanisms and clinical applications

Glioblastoma (GBM) is the most common malignant primary brain tumor in adults and carries poor prognosis. Despite advances in therapy, no significant increase in survival has been achieved for GBM patients. These tumors inevitably recur in the majority of patients, and the therapeutic options for recurrent tumors are limited. GBMs are aggressive, fast-growing, and highly infiltrative tumors, with exuberant angiogenesis (microvascular proliferation) and necrosis. However, the newly formed tumor vessels are structurally and functionally abnormal, creating areas of hypoxia and ultimately necrosis, contributing to tumor progression and aggressiveness. Since GBMs are hypervascular in nature, targeting tumor angiogenesis emerged as a promising therapeutic strategy. In this review, we summarized the molecular and cellular mechanisms governing GBM angiogenesis, the other modes of tumor vascularization, and the key mediators of these processes. We also discussed the importance of tumor hypoxia in promoting angiogenic and vasculogenic processes, the contributions of GBM stem cells to tumor vasculature, the anti-angiogenic therapy for GBM, and the resistance to such therapy. A better understanding of the molecular and cellular basis of GBM neovascularization, the mechanisms of resistance to therapy, and the contributions of GBM stem cells to tumor vasculature will lead to the development of more effective treatment strategies.

First evidence of Brucella ovis infection in rams in the Pirot Municipality, Serbia

This paper describes a research on Brucella ovis infection in rams in the Pirot Municipality of South Serbia. A positive result with indirect immunoenzyme test (i-ELISA) was confirmed in 67 (29.8%) and suspicious in 31 (13.8%) out of 225 tested rams. Complement fixation test (CFT) was used as a confirmation test on 67 ELISA positive sera and gave positive reaction in 41 (61.2%) ram serum samples. Rams originated from 113 flocks with 4751 sheep, from 28 villages in the Pirot Municipality of southern Serbia. Clinical examination was performed on epididymis and testes of 12 rams from 7 seropositive flocks by inspection and palpation. The examination showed scrotum asymmetry and unilateral increase of the epididymistail in 5 (41.7%) out of 12 seropositive rams. Pathomorphological examination of testes and epididymis confirmed pathological changes in 7 (58.3%) of the 12 examined rams. Onesided epididymitis with pronounced hypertrophy of the epididymitis was also confirmed. Twelve rams were tested for the presence of bacteria, i.e. 21 epididymis, testes and lymph nodes samples. We isolated 20 Brucella strains from 11 (91.7%) of the 12 examined animals. All isolates were identified with bacteriological and molecular techniques as B. ovis. This is the first evidence of ovine epididymitis (B. ovis) in Republic of Serbia.

Umbilical endometriosis associated with large umbilical hernia. Case report

Umbilical endometriosis is a rare condition, usually following laparoscopic and surgical procedures involving the umbilicus.Spontaneous umbilical endometriosis occurring without any previous abdominal or uterine surgery is extremely rare. The maximal depth of penetration of the umbilical endometriosis described is up to fascial level. There have been only two cases of endometriosis reported arising within umbilical hernia. The authors report a case of a patient with spontaneous umbilical endometriosis associated with a large umbilical hernia, treated by surgical excision and mesh repair of the abdominal wall. To the best of our knowledge, this is the first described case of the association of umbilical endometriosis with a large umbilical hernia that requires prosthetic mesh repair of the abdominal wall defect.

Correlation of nuclear morphometry of primary melanoma of the skin with clinicopathological parameters and expression of tumor suppressor proteins (p53 and p16(INK4a)) and bcl-2 oncoprotein

PURPOSE

To determine the correlation of nuclear morphometry of primary cutaneous malignant melanoma (CMM) with clinicopathological parameters and the expression of p53, p16INK4a, and bcl-2.

METHODS

Image analysis and computerized nuclear morphometry were used in a series of 53 primary CMM (nodular melanoma/NM, N=33, and superficially spreading melanoma/SSM, N=20). The clinicopathological parameters determined for each tumor were histological type, maximal tumor diameter, Breslow thickness, Clark level, ulceration, mitotic index (MI) and pathological disease stage. Measured nuclear features included size, shape and optical density (OD). The results were correlated with the expression of p53, p16INK4a and bcl-2.

RESULTS

Significant differences between NM and SSM were found for the nuclear area, OD, and perimeter (p<0.05). MI showed significant correlations with nuclear area, perimeter and Feret diameter (p<0.05). In relation to the Clark level, significant differences were found for OD (p<0.01) and circularity of nuclei (p<0.05) between levels II and IV, while the Breslow thickness was not significantly correlated with nuclear morphometric variables. Significantly negative correlations were observed between OD and the expression of p53 and bcl-2, while significant positive correlation was found between the nuclear circularity and p53 immunoreaction intensity. There was no significant correlation between the expression of p16INK4a protein and karyometric variables.

CONCLUSION

OD and circularity are significantly correlated with p53 and bcl-2, and nuclear area with MI. These karyometric variables may determine a more aggressive phenotype of melanoma cells.

Correlation of cell cycle regulatory proteins (p53 and p16(ink)⁴(a)) and bcl-2 oncoprotein with mitotic index and thickness of primary cutaneous malignant melanoma

The purpose of the study was to determine the frequency of expression p53 and p16INK4a proteins and bcl-2 oncoprotein in malignant skin melanoma and to determine their correlation with the proliferative index and tumor thickness. The study involved 53 patients: 27 (51%) male and 26 (49%) female. Mitotic index showed a correlation with p53 protein expression, a negative correlation with p16INK4a protein expression. Statistically significant correlations were determined between the Breslow tumor thickness, Clark invasion level and p53 protein expression, as well as Breslow tumor thickness and bcl-2 oncoprotein expression (p<0.05), whereas there was no correlation between the p16INK4a protein expression and melanoma thicknes and Clark invasion level. Overexpression p53 protein and bcl-2 oncoprotein, with the loss p16INK4a protein of expression in the nodular melanoma, confirms a frequent loss of function of these tumor suppressor gene and oncogene, and indicates a vertical tumor growth phase. The loss of tumor suppression function the p53 protein and bcl-2 oncoprotein overexpression in cutaneous melanoma correlates with larger tumor thickness, whereas the overexpression of mutated p53 protein and loss p16INK4a protein of expression indicate a higher proliferative tumour potential. Therefore, these evaluated proteins may be the aggressive biological tumour activity markers.

[Use of fibrin glue in the prevention of leakage in pancreatico-jejunal anastomoses]

The aim of this study was to test the protective effects of fibrin sealing on the pancreatico-jejunostomy (PJA), the high-risk anastomosis following pancreas head resection. Experimental study was performed on the mongrel dogs, divided in two groups (20 animals each): Experimental group-with end to end "dunking" PJA, protected by temporary occlusion of the pancreatic duct with fibrin sealant/Tissucol/Immuno Ag/, while control group was without any protective procedure. The animals were followed 5 months in order to study: protective effects of such procedure on the PJA quantified with the percent of anastomotic leakage, effects of the exocrine secretion and effects the endocrine function Results: PJA leakage occurred in 13.33% in control group. No leakage was registered in experimental group. Biochemical, histological and electron microscopic study showed slight transitory elevation of amylase levels. Fibrin glue plug was dissolved and pancreatic juice output was reestablished 12th days postoperatively. Long term follow-up showed no damages of the endocrine and exocrine pancreas. Pancreatic duct occlusion with fibrin glue appeared to be an useful method in the prevention of pancreatico-jejunostomy leakage, without negative effects on the exocrine and endocrine pancreas.

[Experimental and clinical possibilities of transplantation of the injured and totally devascularized spleen]

The most severe spleen lesions with conquasation and devascularisation of entire organ, when it is practically impossible to do any preservating surgical procedure, are the true indications for the transplantation of this extremely important immunological organ. We have performed the evaluation of the surgical procedure of heterotopic auto transplantation in the 30 dogs with severe spleen lesions. Simulation of totally devascularized spleen with the lesions of V degree was performed by disrupting all segmental blood vessels with deep and long longitudinal transhilar incision. During the 3 months follow-up period, animals were subjected to numerous explorations in order to macroscopically and histologically valuate the implant. In most cases (80-85%) implants had complete vitality with the preservation of normal tissue architecture, while 15-20% of implants had partial or total fibrosis. There were no mortality and no complications after this preservation procedure. The presence of fibrosis in some implants suggests that the implant preparation should be better performed and that transplantation of larger tissue volume is needed. Enriched with this experimental experience we have performed heterotopic auto transplantation in 2 patients with spleen lesion of V degree (car accident and injury at work) with very satisfactory results.

[Ochronosis--an autopsy case report]

The authors have presented a case of ochronosis, as the incidental finding during the autopsy of a female patient, aged 59 years. It was the case of suicidal drug poisoning. Ochronosis is a rare disease, with chronic benign course, but frequently followed by complications. Histopathological criteria for the diagnosis of this disease are described in detail.