Biomedical subjects

Joachim Bennek

Publications and source records attributed to Joachim Bennek.

7 recordsLinked to original sources

PubMed2006

Experimental study evaluating the effect of a barrier method on postoperative intraabdominal adhesions.

The purpose of this animal study was to determine if tissue glue-coated collagen sponge is an effective barrier method to prevent localized adhesions in a modified rabbit sidewall model. Rabbits were divided into two groups and underwent laparotomy with subsequent creation of a cecal wound according to the rabbit sidewall model. Rabbits of group I (treatment group; n = 10) were treated with a TachoComb H patch placed on the defect, whereas group II animals (control group; n = 6) did not receive further treatment. All animals were sacrificed 2 weeks postoperatively and adhesions were evaluated using special adhesion score. A further six rabbits underwent TachoComb H application at the cecum to investigate the histological changes during a course of 12 weeks. The average adhesion scores were significantly (P < 0.05) reduced in the treatment group compared to the controls. Histologically the TachoComb H patch was surrounded by granulation tissue without signs of infection. Tissue glue-coated collagen sponge (TachoComb H) is effective to prevent localized intraabdominal adhesions in the modified rabbit sidewall model.

Abdominal Wall↗

PubMed2005

TNP-470 fails to block the onset of angiogenesis and early tumor establishment in an intravital minimal disease model.

BACKGROUND AND AIMS: The angiogenesis inhibitor TNP-470 (AGM-1470) has shown encouraging results in animal models of established tumors. However, results of recent clinical trials using TNP-470 have been disappointing. Since little is known about the effects of TNP-470 at the minimal disease stage, we analyzed the effects of TNP-470 on the early stages of tumor establishment. METHODS: Twenty thousand green fluorescent protein (GFP)-transfected murine CT-26 (colonic carcinoma) or Panc-02-H0 (pancreatic adenocarcinoma) cells were inoculated in dorsal skin-fold chambers in BALB/c or C57BL6 mice. Tumor area and microvessel density (MVD) were quantified by intravital microscopy (IVM). Body weight was also monitored. Effects were compared with those in a conventional model involving subcutaneous (s.c.) inoculation of 10(6) tumor cells, followed by measurement of tumor volume, endogenous plasma VEGF/endostatin (ELISA) and proliferation/apoptosis/microvessel density (Ki-67/TUNEL/CD-34). TNP-470 was injected s.c. over the 10-day experimental period (30 mg/kg every 2 days [n=6] to 100 mg/kg/day [n=5 dorsal skin-fold chamber model, n=4 s.c. tumor model]). RESULTS: At 30 mg/kg/every second day neither CT-26 nor PANC-02-H0 tumors were inhibited in neither of the two models. TNP-470 dosage was escalated in CT-26-bearing animals until an antiangiogenic effect could be observed. In the IVM model, only TNP-470 100 mg/kg/day reduced MVD (P=0.006), but failed to block the onset of angiogenesis and tumor area increase. Body weight decreased by 25% (P<0.05). In the subcutaneous tumor model, tumor growth was reduced (P=0.045) but not blocked, while vascular endothelial growth factor (VEGF)/endostatin synthesis and Ki67/TUNEL/CD-34 were not significantly affected. CONCLUSION: While capable of reducing tumor growth in a conventional model, treatment with TNP-470 does not block the onset of angiogenesis and tumor establishment in a model of minimal disease. When used as a single agent TNP-470 does not control minimal tumor disease in experimental colonic carcinoma.

Angiogenesis Inhibitors↗

PubMed2005

Peritoneal taurolidine lavage in children with localised peritonitis due to appendicitis.

Despite aggressive surgical treatment, rational antibiotic therapy, and modern intensive care, generalised peritonitis remains a major threat in the paediatric age group. Several adjuvant strategies such as peritoneal saline lavage and peritoneal drainage have been utilised. Taurolidine, derived from the amino acid taurine, has bactericidic, antiendotoxic, and antiinflammatory properties. It has been introduced previously for intraoperative peritoneal lavage in treating peritonitis in adults. The aim of our study was to evaluate the effect of peritoneal taurolidine lavage on the clinical course and serological inflammation markers in children with perforated appendicitis and localised peritonitis. A series of 27 children presenting with appendicitis between January 1999 and July 2001 were included in the study after parental informed consent. All patients underwent open appendectomy. Taurolidine peritoneal lavage was applied in 15 randomly selected children (eight girls and seven boys; mean age 10 years and 10 months). Twelve children received saline peritoneal lavage and served as the control group (six girls and six boys; mean age 9 years and 7 months). Blood was taken preoperatively and on postoperative days 1, 3, 7, and 14. Full blood cell count, C-reactive protein, endotoxin, interleukin-1, interleukin-6, soluble interleukin-2 receptor, tumour necrosis factor alpha, and procalcitonin were investigated to evaluate the serological course of inflammation. Both groups initially presented with severe inflammation as evidenced clinically and serologically. The clinical postoperative course was uneventful in 13/15 patients in the treatment group and 10/12 patients in the control group. The remaining patients presented complications: intraperitoneal abscess or early postoperative bowel obstruction. With regard to the serological inflammatory parameters, no significant differences were found between the two groups except for the soluble interleukin-2-receptor on the 7th postoperative day. In conclusion, the expected reduction of endotoxin levels and inflammatory activity in the treatment group was not evident. A significant advantage of adjuvant peritoneal taurolidine lavage in the surgical therapy of children with localised peritonitis due to appendicitis could not be shown in our study.

Anti-Infective Agents↗

PubMed2004

Pregnancies in patients with congenital adrenal hyperplasia with complete or almost complete impairment of 21-hydroxylase activity.

OBJECTIVE: To show that, with appropriate therapy, women with classic congenital adrenal hyperplasia (CAH) can become pregnant. DESIGN: Observational clinical study. SETTING: University hospital. PATIENT(S): Adult young women with CAH: three with the salt-wasting form and four patients with simple virilizing CAH due to severe homozygous or compound heterozygous mutations of the CYP21B gene (deletions, I172N in exon 4 and nt656A/C-->G in intron 2) who wished to become pregnant. INTERVENTION(S): After confirmation in the first patient of the beneficial effect of additional treatment with fludrocortisone in lowering 17alpha-hydroxyprogesterone (17-OHP) levels, five other patients were treated with hydrocortisone as three daily doses at 8-hour intervals and fludrocortisone 0.1-0.2 mg daily divided into two to three doses. One patient received glucocorticoid alone. MAIN OUTCOME MEASURE(S): Treatment was controlled on the basis of morning salivary 17-OHP estimates and plasma renin concentrations. RESULT(S): Nine pregnancies occurred in six women. The course of the pregnancies (except one spontaneous abortion) was normal without any other modification of therapy. Only the women treated with hydrocortisone alone did not become pregnant. CONCLUSION(S): When treated with a combination of glucocorticoids and mineralocorticoids, sexually active patients with the classic phenotype of CAH can become pregnant.

17-alpha-Hydroxyprogesterone↗

PubMed2003

Oral tumors and tumor-like lesions in infants and children.

The aim of this retrospective study was to survey the spectrum of oral tumors and tumor-like lesions treated in a pediatric surgical unit. The clinical features and treatment outcome are presented, and guidelines for management discussed. Long-term follow-up was carried out both by re-examination and by means of a questionnaire. A total of 95 patients were encountered over a 30-year period. The age at presentation ranged from 1 day to 16 years, and the male to female ratio was 0.7:1. The lesions were located predominantly on the lips (22%), tongue (21%), and cheek (19%). Patients were divided into five groups based on histological diagnosis. Benign lesions accounted for 83 (87%) of the cases. Of these, 41 (43%) were benign tumors, the most common of which were the hemangiomas (17 cases). Hamartomas accounted for a further 22 benign lesions (23%), among which 12 were lymphangiomas. Furthermore, we saw 14 cases (15%) of mucoceles, ranula and dysontogenetic cysts, and a further 6 cases (6%) were classed as miscellaneous lesions. Simple surgical resection was successful in treating most benign lesions, with occasional re-excision being necessary in lymphangiomas. The long-term effects of treatment include reduction of the red volume of the lips, scarring following resection of parotid hemangiomas, a forked tongue after wedged resection, and partial facial nerve palsy. The group of 12 (13%) malignant tumors consisted of 5 rhabdomyosarcomas, 2 fibrosarcomas, 2 carcinomas of the parotid, 1 osteosarcoma, and 2 metastases. A multimodal approach was used in patients with rhabdomyosarcomas, while fibrosarcomas and parotid carcinomas were normally treated by surgical excision. Six of 12 patients with malignant tumors were alive after a median follow-up of 20.5 years. Re-examination of the malignant tumor group revealed scarring, impaired growth and function of the maxilla associated with local irradiation, and an external salivary fistula. In conclusion, while most oral and maxillofacial tumors of children are benign, malignant tumors of soft tissue, salivary glands and bones must be taken into account. There are specific aspects related to certain developmental and biological characteristics that make a mainly conservative approach preferable in these children.

Adolescent↗

PubMed2002

Pheochromocytoma and multifocal functioning paraganglioma in a 9-year-old boy with von Hippel-Lindau disease.

We report the case of a 9-year-old boy presenting with multifocal paraganglioma partially involving the right suprarenal gland, abdominal paraganglia, and the left para-aortal retropleural region. Von Hippel-Lindau disease (VHL) was diagnosed exclusively by VHL-gene analysis. Other clinical signs of VHL were lacking. After a complaint-free period of 7 months the boy developed a metachronous paraganglioma adjacent to the opposite adrenal gland. Patients with VHL disease should undergo adrenal-sparing surgery.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Proteus syndrome.

Proteus syndrome is a rarely described dysplasia syndrome of the group of congenital hamartomas that arises from mosaic mutation. An extraordinary case history including imaging studies will be reported. This 17-year-old girl suffered from cachexia, lifelong chronic obstipation, different dysplasias, and lipomatous tumor-like lesions. The following findings were marked: macrodactyly, nevi, hemihypertrophy, aggressive lipomatosis, hemangiomas of the spleen, and skull and cerebral malformations. Additionally, an intestinal affection with fatty wall thickening was detected. In contrast to reports in the literature describing a reduced lifespan with a mean of few years, our patient is still alive. The treatment should take a palliative symptomatic approach considering the clinical situation.

Adipose Tissue↗