Establishment of a mouse model with misregulated chromosome condensation due to defective Mcph1 function

Mutations in the human gene MCPH1 cause primary microcephaly associated with a unique cellular phenotype with premature chromosome condensation (PCC) in early G2 phase and delayed decondensation post-mitosis (PCC syndrome). The gene encodes the BRCT-domain containing protein microcephalin/BRIT1. Apart from its role in the regulation of chromosome condensation, the protein is involved in the cellular response to DNA damage. We report here on the first mouse model of impaired Mcph1-function. The model was established based on an embryonic stem cell line from BayGenomics (RR0608) containing a gene trap in intron 12 of the Mcph1 gene deleting the C-terminal BRCT-domain of the protein. Although residual wild type allele can be detected by quantitative real-time PCR cell cultures generated from mouse tissues bearing the homozygous gene trap mutation display the cellular phenotype of misregulated chromosome condensation that is characteristic for the human disorder, confirming defective Mcph1 function due to the gene trap mutation. While surprisingly the DNA damage response (formation of repair foci, chromosomal breakage, and G2/M checkpoint function after irradiation) appears to be largely normal in cell cultures derived from Mcph1^gt/gt mice, the overall survival rates of the Mcph1^gt/gt animals are significantly reduced compared to wild type and heterozygous mice. However, we could not detect clear signs of premature malignant disease development due to the perturbed Mcph1 function. Moreover, the animals show no obvious physical phenotype and no reduced fertility. Body and brain size are within the range of wild type controls. Gene expression on RNA and protein level did not reveal any specific pattern of differentially regulated genes. To the best of our knowledge this represents the first mammalian transgenic model displaying a defect in mitotic chromosome condensation and is also the first mouse model for impaired Mcph1-function.

Oxaliplatin for chemotherapeutic treatment and prevention of experimental peritoneal carcinomatosis in rats comparing the intraperitoneal and intravenous application mode

BACKGROUND

The occurrence of peritoneal carcinomatosis after resection of colorectal carcinoma is still a major concern. In this study, we tested the cytostatic agent oxaliplatin delivered intraperitoneally and intravenously to prove whether it can significantly reduce intraperitoneal tumor growth.

METHODS

Peritoneal tumor growth was experimentally induced with transfer of CC-531 colon cancer cells (5 x 10(6)) to the peritoneal surface of rats via laparotomy. Oxaliplatin was delivered either intraperitoneally or intravenously. In group A, oxaliplatin was administered directly after tumor cell transfer. While oxaliplatin was applied in group B on days 5, 10, and 15 after tumor cell implantation, in group C, it was administered on days 10, 15 and 20. The rats were sacrificed on day 30 after tumor cell transfer. Tumor weight, relative increase in tumor mass, volume of malignant ascites and the number of tumor nodes were determined.

RESULTS

Oxaliplatin significantly inhibited tumor growth after direct (group A) and early postoperative application (group B) via the intraperitoneal route. The late postoperative administration of oxaliplatin (group C) did not cause a significant effect on peritoneal tumor growth as it did with the intravenous application mode in groups A, B, and C.

CONCLUSIONS

In this experimental model, oxaliplatin was highly effective against intraperitoneal tumor spread but only with the intraperitoneal application route. Other cytostatic agents with different effector mechanisms should be combined with oxaliplatin to further increase the therapeutic efficacy of the favorable intraperitoneal treatment in subsequent studies testing, in addition, the effects on wound and anastomosis healing.

[Current diagnosis and treatment of desmoid tumours in patients with familial adenomatous polyposis - the surgical view]

Based on a representative selection of relevant references, the aim of this study was to reflect the change of the algorithm in the surgical management of desmoid tumours (DT) in cases of accompanying familial adenomatous polyposis (FAP). Main focus is concerned with the basics of differential treatment, including additional considerations on epidemiology, diagnosis, outcome and follow-up. DT are rare benign tumours that do not metastasise but tend to invade locally. In contrast to the general population, DT in patients with FAP are more common, show a different pattern of tumour sites and cause considerable morbidity and mortality. Most DT occur in the abdominal cavity and account for the majority of serious problems. Genetic disposition and hormonal factors as well as prior surgical trauma are considered causative for the development of DT. Characteristic symptoms are abdominal pain, nausea and vomiting but DT may also present as acute abdomen. CT scan determines localisation and extension of the tumour. Treatment includes various strategies of medication, surgical resection and radiation. Data concerning diagnostic and therapeutic procedures are based on studies with small case series or case reports only. Therefore data from international multicentre studies are necessary for improving the prognosis and developing reliable and stringent guidelines.

[A rare extra-skeletal myxoid chondrosarcoma of the lower leg - is amputation absolutely necessary]

INTRODUCTION

Sarcomas represent less than 2 % of all malignancies. Special challenges are bone sarcomas in extra-skeletal localisation. The aim of this case report is to show the management of an extraordinary extra-skeletal myxoid chondrosarcoma based on a case report with references from the literature.

CASE REPORT

After a delay in diagnostics for 1.5 years, an MRI scan taken in a 42-year-old male patient with progressive swelling of the left calf showed a soft-tissue tumour in the proximal part of the muscle. Histopathological investigation of a percutaneous biopsy revealed a chondrosarcoma. En-bloc-resection (R 0) of the rear superficial compartment was performed (specimen weight 1 370 g; tumour size 11.5 x 9.5 x 8 cm) leading to the definitive diagnosis of an extra-skeletal myxoid chondrosarcoma. The patient was discharged with a bland wound 8 days after surgery. At 4 weeks postoperatively, the patient received adjuvant radiotherapy with a 56-Gy boost. During the follow-up period of 28 months, there have been neither signs of local tumour recurrence nor distant metastases.

DISCUSSION

The myxoid chondrosarcoma is a rare tumour lesion, and according to the literature, only 2 % occur outside of the skeleton. The accurate diagnostic and therapeutic algorithm allowed a precise preparation for surgery and made amputation obsolete. Compartment resection preserving the main neurovascular bundles as well as enabling an early mobilisation resulted in both sufficient radical resection status and adequate postoperative motor function. Intraoperative clip-marking of the former tumour bed is considered a key point for the focused radiotherapy.

CONCLUSION

Each persistent soft tissue swelling must be appropriately diagnosed using adequate imaging and even biopsy (in case of a doubtful finding), which should be performed with definitive surgery in mind.

Hybrid approach: vascular surgical and image-guided intervention for BroCa-induced superior vena cava syndrome (SVCS)

BACKGROUND

The aim of this study was to compare the outcome of a novel hybrid technique with the results of conventional approaches when treating tumor-induced superior vena cava syndrome (SVCS). The failure of a thrombectomy via transjugular aspiration led to an interdisciplinary approach to treat malignant SVCS.

METHODS

The technique is relatively unknown but is performable if vascular surgeons and interventional radiologists work side by side in the operating room. We give an in-depth description of the hybrid technique, including surgical thrombectomy of the SVC, left brachiocephalic vein and left subclavian vein, occlusion balloon placement, stenting of the SVC and left brachiocephalic vein and the imaging controls. The equipment needed for this approach must be in the operating room and may only be available in bigger hospitals.

RESULTS

Tumor-induced SVCS is an urgent case that sometimes cannot wait for radiotherapy or chemotherapy to reduce the tumor mass compressing the SVC. The results of our hybrid technique included almost complete relief of SVCS symptoms within 24 hours. The patient was discharged two days after surgery.

CONCLUSION

Treatment provided the advantages associated with limited invasiveness, i.e., a faster and complication-free recovery period. The procedure may be a suitable alternative to open surgical intervention, as it involves less invasive trauma and has a reasonable risk-benefit ratio with a good chance of technical and clinical success. Further studies are warranted to better assess the complication rates with this hybrid technique.

[Colon triplication associated with ileum atresia in laparoschisis]

The present paper reports the unusual and rare case of a colon triplication associated with other findings never reported before, including the diagnostic and therapeutic management with consideration of the relevant, but rare scientific references in the medical literature. In the basic finding of an ileum atresia with laparoschisis, a colon triplication was incidentally found. The surgical procedure performed after the primarily planned Caesarean section within the 34(th) week of gravidity consisted of a bowel-preserving resection of the triplication including the ileum atresia and a subsequent Santulli anastomosis followed by a later excision of the ileostoma. Interestingly, this is the 9(th) reported case in the accessible English medical literature but, however, the first and only one with an associated ileum atresia and laparoschisis, which was successfully treated with a surgical intervention.

[Successful open vascular-surgical supracoeliac anastomosis of a bifurcational prosthesis with simultaneous prosthetomesenteric and renal revascularisation in Leriche's syndrome with high occlusion]

BACKGROUND

Based on an extraordinary case -report on a patient with almost symptomless supramesenteric occlusion of the aorta, the successful management and favourable outcome including almost normalised renal function (in addition to appropriate diagnostic and operative tactics) achieved by a technically challenging vascular-surgical intervention and subsequent intensive medical and nephrological care are described.

RESULTS

In a 49-year-old male patient, a "high" aortic occlusion just below the branching of the coeliac trunk with arterial perfusion of the abdomen and the lower extremities via arterial collaterals from the 4 (th) to 6 (th) intercostal arteries was diagnosed. Both renal arteries were occluded leading to a consecutive renal insufficiency with need for dialysis and renovascularly induced hypertension. However, a residual perfusion of the parenchyma of the left kidney was detectable. Therapeutic measures comprised, after haemodialysis with accompanying antihypertensive medication, open supracoeliac aortobifemoral implantation of a prosthesis, revascularisation of the left renal artery (prosthetic bypass) and prostheticomesenteric bypass implantation. Postoperatively, a reestablished renal perfusion was observed in spite of the preoperatively prolonged lack of appropriate arterial perfusion (last dialysis, 11 (th) POD / discharge, 18 (th) POD). At 3 months postoperatively, the patient reported an increase of his body weight of 8 kg (at 6 months, 20 kg; improved but still elevated laboratory parameters indicating renal insufficiency; RR within normal range). Postinterventional MR angiography revealed a regular perfusion of the bifurcational prosthesis and of the bypasses to the superior mesenteric and left renal arteries.

CONCLUSION

This exemplary case demonstrates impressively the individual therapeutic chances, options and the potential in the diagnostic and therapeutic interdisciplinary management and its combined expertise. The clinical course in this case indicates that the assessment of the arterial blood supply has to be included in the diagnostic of an acute renal insufficiency associated with anuria. If there is a minimal residual perfusion, which might just be sufficient for maintenance of structural integrity, there is a real chance for a restitution of renal function after successful revascularisation.

[Spectrum of indications and perioperative management in i. v. port-a-cath explantation--alternative administration of taurolin in case of i. v. port-a-cath infection]

BACKGROUND

The aims of this systematic investigation were to analyse i) causes and complications leading to i. v. port-a-cath explantation and ii) a specific therapeutic option (taurolin administration via i. v. port-a-cath) in the case of an i. v. port-a-cath infection in a pilot study with regard to the feasibility and efficacy to finally avoid -explantation.

PATIENTS AND METHODS

Based on a prospective, unicentre observational study on the implantation of an i. v. port-a-cath (daily surgical practice) enrolling consecutive patients of a representative number and through a defined study period (design, case series), besides patient and intervention-associated characteristics, we investigated 1. the spectrum of causes for an i. v. port-a-cath explantation; 2. the option of a conservative i. v. port-a-cath-maintaining, endoluminal, antiseptic local therapy in a selected number of patients with microbiologically detected infection of the i. v. port-a-cath using 2 x 5.0 ml taurolin 2.0 % / d for 3 d as an accompanying clinical observation of initial therapeutic use and its effect. Thereafter, microbe detection was again compared between blood culture and the port-a-cath catheter.

RESULTS

From 2002 to 2005, overall 1588 i. v. port-a-caths were implanted at the Department of -General, Abdominal and Vascular Surgery (University Hospital, Magdeburg, Germany). 1) In -total, 117 patients (69 females vs. 48 males; sex ratio, 1.44 : 1) with complications and subsequent indication for an explantation of the i. v. port-a-cath were observed (most frequent cause: infection of the i. v. port-a-cath, 40 %). 2) Taken together, 10 patients underwent systematic administration of taurolin and follow-up investigation: In 8 of 10 patients (success rate, 80 %), the infection of the i. v. port-a-cath could be successfully treated with taurolin-administration as described and, in addition, the threatening -explantation of the i. v. port-a-cath could be avoided.

CONCLUSIONS

There are various indications for the necessary -explantation of an i. v. port-a-cath, which need to be precisely analysed to avoid long-term consequences. Infection of the i. v. port-a-cath is the main reason for explantation and may be successfully treated with taurolin in selected cases under short-term clinical and microbiological control. The up to now urgently indicated explantation of an i. v. port-a-cath can thus be circumvented. However, a further systematic case series with a representative case number and intermediate, case-specific follow-up investigations appear to be desirable.

A retrospective analysis of emergency double-balloon enteroscopy for small-bowel bleeding

Although the role of emergency esophagogastroduodenoscopy (EGD) and colonoscopy for upper and lower gastrointestinal bleeding (GIB) is well defined, there are no data on the concept of emergency double-balloon enteroscopy (DBE) for small-bowel bleeding. The aim of this study was to retrospectively evaluate the concept of emergency DBE in overt obscure GIB and assess its impact on patient management. A total of 17 emergency DBEs for overt obscure GIB were carried out in ten patients (six women, four men; mean age 68 years, range 35 - 83). The following diagnoses were made: actively bleeding Dieulafoy lesions of the small bowel, n = 2; bleeding tumors, n = 4 (carcinoids n = 2, adenocarcinoma n = 1, lipoma n = 1); bleeding angiodysplasias and/or large arteriovenous malformation (AVM), n = 2; multiple ulcers, n = 1; and no diagnosis, n = 1. Endoscopic therapies included argon plasma coagulation (n = 6), injection of epinephrine (n = 3), and use of fibrin glue (n = 1). It appears that emergency DBE is technically feasible, facilitates both diagnosis and therapy and enables management of patients with massive overt obscure GIB. This study is a first step in establishing the concept of emergency DBE for patients with suspected small-bowel bleeding.

[Microbiological sepsis screening in surgical ICU patients with the "lightCycler" Septifast test--a pilot study]

INTRODUCTION

An adequate approach to surgically induced sepsis needs an early and targeted antibiotic therapy in addition to focus sanitation. The PCR-based LightCycler Septifast test can detect 90 % of the sepsis-associated microoganisms (e. g., Gram-positive, Gram-negative bacteria, fungi) within only a few hours.

PATIENTS AND METHODS

A systematic microbiological screening was performed using conventional cultures from blood, urine, drain material and tracheal secretions as well as with the culture-independent Septifast test (blood supplemented with EDTA) as a comparison in consecutive surgical patients on the intensive care unit within a defined time period.

RESULTS

Overall, 52 patients were enrolled in the investigation during the study period of 4 months. Out of overall 258 Septifast tests, 33 (12.8 %) were positive. Additional information on the microbial spectrum was achieved in 24 cases (72.2 %) when compared with the simultaneously performed conventional blood cultures; 32 (12.4 %) of 258 blood cultures were positive. If the frequent occurrence of coagulase-negative STAPHYLOCOCCUS (CNS) is classified as contamination, blood cultures resulted 10 times (31.3 %) in additional information compared with the Septifast test including the CNS in 20 cases (62.5 %). Except for Proteus mirabilis, this refers to microorganisms which are not in the analytical spectrum of the Septifast(R) test. A positive Septifast test showed a high coincidence with SIRS (75.8 %).

CONCLUSION

This first systematic use of the time-saving LightCycler Septifast test shows that it can detect bacteremia in surgical patients at the ICU, with, in part, negative blood cultures. Positive Septifast test results which cannot be explained by clinical symptoms, occur rarely. The detection of pathological microbes with the Septifast test provides additional findings (72.2 %) for therapeutic decision-making, which can be obtained considerably more rapidly in comparison with conventional microbiological cultures (a few hours versus 2 days). For surgical patients with SIRS and subsequent need of intensive care, a Septifast test should be considered. In conclusion, it is recommended that the test should be further and systematically investigated.

[Microbial spectrum in surgical infections based on a microbiological routine monitoring over the 10-year period from 1995 to 2004]

INTRODUCTION

Infections belong to the most frequent and dangerous complications in surgery. In addition to the medical aspects, these infections may have a significant impact on the costs and the overall economic efficacy of medical treatment under the present circumstances of DRG.

AIM

A systematic, prospective collection and retrospective evaluation of all consecutive microbiological analyses in specimens from the 3 medical floors (except the ICU) of the Department of Surgery at the University Hospital, Magdeburg (Germany) was performed in 1995, 2002 and 2004 to characterise i) the 10-year course (1995 vs. 2004) and ii) possible alterations due to changes in the previously existing pavillon system (2002 vs. 2004).

PATIENTS AND METHODS

The microbial spectrum was determined in the 3 most frequent specimen types (blood culture, urine sample, wound swab) including number and percentage of the single microbial groups such as gram-positive and gram-negative Enterobacteriae, pseudomonades and fungi. In addition, the antibiotic resistance of selected microbes was analysed. The primary data were registered in a database and evaluated according to the various questions.

RESULTS

Overall, 2 979 microbes were identified in 1995 (2002, 1 338; 2004, 915). On comparing 1995 with 2004, the percentage of gram-positive microbes did not change (50.5 vs. 50.3 %), whereas the percentage of gram-negative enterobacteriae increased: 37.4 vs. 29.1 %. The percentage of detected fungi was only half of that in 1995: 6.2 vs. 12.2 %. In blood cultures, the Klebsiella spp. portion in the group of gram-negative enterobacteriae distinctly increased: 29.6 vs. 18.8 %. While in 2004, MRSA was found in 24.4 % of all detected Staphylococcus aureus strains in swab specimens amounting to a considerable increase compared to 2002 (17.6 %), in 1995, MRSA was not isolated at all in this material. In the fungi group, there was a decrease of the Candida albicans portion vs. the non-C. albicans strains, which was associated with an increasing resistance against fluconazol. This requires treatment with caspofungin, resulting in increased costs vs. those necessary for fluconazol treatment.

CONCLUSION

A systematic, microbiological, long-term monitoring is indispensable since i) microbial detection plays a growing role to include the various types of infections in the spectrum of diagnosis for DRG, ii) alterations of the microbial spectrum can only be detected through a long-term observation period (MRSA, fungi) and iii) simultaneously developing antibiotic resistances can be determined (MRSA, ESBL strains in Enterobacteriae, fluconazol-resistant fungi). This can have an infectious, biological, hygienic and cost-determining as well as a health policy relevance among others, with considerable additional costs (e. g., isolation of patients, cost-intensive substitutional medication) with necessary reimbursement.

Evidence of thromboembolism prophylaxis in bariatric surgery-results of a quality assurance trial in bariatric surgery in Germany from 2005 to 2007 and review of the literature

BACKGROUND

Since January 1st, 2005, the current situation for bariatric surgery has been examined by means of a voluntary quality assurance study in Germany with a multicenter design in which 38 hospitals and surgical departments participated. The data are registered in cooperation with the Institute of Quality Assurance in Surgery at the Otto-von-Guericke University of Magdeburg (Germany).

METHODS

Data describing peri-interventional characteristics were prospectively documented in an internet online data registry. All primary bariatric procedures performed since January 1st, 2005, were registered. In addition, reoperations in patients who had previously undergone primary surgical intervention were included. As a representative excerpt from the overall prospective multicenter observational study on obesity surgery, data on the type, regimen, and time course of deep venous thrombosis (DVT) prophylaxis were documented. From the number and spectrum of complications, the incidences of clinically manifest DVT or pulmonary embolism (PE) were derived during the in-hospital course and follow-up in conjunction with the type of surgical procedure and body mass index (BMI).

RESULTS

Overall, 3,122 bariatric procedures were performed at 38 German hospitals between January 2005 and December 2007. These procedures were subdivided into 2,869 primary operations and 253 revisions (sex ratio, male to female = 25.6:74.4%). The average BMI of all patients was 48.5 kg/m(2) in 2005, 48.4 kg/m(2) in 2006, and 48.0 kg/m(2) in 2007. In 2005 and 2006, gastric banding (GB) was the most commonly performed operation, followed by Roux-en-Y gastric bypass (RYGBP). In 2007, RYGBP was carried out in 42.1% of all bariatric procedures. Interestingly, the incidence of deep venous thrombosis (DVT) was only 0.06%, whereas PE occurred in 0.06% of patients only after hospital discharge. The DVT prophylaxis protocol used has been changed for the last 2 years: the majority of patients with a BMI above 50 kg/m(2) received low-molecular-weight heparin twice a day.

CONCLUSION

In Germany, a trend from GB to sleeve gastrectomy (SG) and malabsorptive approach has been evaluated. This trend is associated with differences of the DVT prophylaxis regimen in the profile of bariatric surgical patients depending on BMI and the type of bariatric procedure. Despite the low incidence of DVT and pulmonary embolism (PE) detected, there is a lack of evidence on a reasonable regimen for sufficient DVT prophylaxis in bariatric surgery; instead, there are only recommendations from the guidelines and statements of a specific medical society. Therefore, prospective studies are necessary to determine the optimal DVT prophylaxis for bariatric surgical patients as well as obese patients undergoing surgery.

[Acute inguinal swelling--unusual presentation of postoperative necrotising pancreatitis]

Necrotising pancreatitis presenting as an acute inguinal swelling is an extremely rare condition. We report on a 61-year-old male who underwent explorative laparotomy for pancreatic tumour. Intraoperatively, the diagnosis of a locally advanced carcinoma of the head of the pancreas was confirmed histologically. During the postoperative course, the patient developed an acute inguinal swelling, which was suspected to be an incarcerated hernia. Intraoperatively, exploration of both abdomen and inguinal canal revealed an acute necrotising pancreatitis. This case is, to the best of our knowledge, the first case report on a postoperative necrotising pancreatitis masquerading as an incarcerated inguinal hernia in an adult male, and the diagnostic problems are discussed.

[Differential value of the diagnostic options to determine the level of amputation]

The level of amputation after utilizing all possible options of revascularization is considered one of the substantial criteria for sufficient reconvalescence, recovery of mobility, reduction of perioperative mortality and, finally, social reintegration. In case of vascular genesis, the possibilities to reestablish or improve arterial perfusion need to be proven. According to the data from the literature on the various technical methods, only the ptO2 measurement has become widely accepted to determine efficiently the level of amputation. In addition, study results have given evidence for the distal shifting to the genual and infragenual level of amputation. Furthermore, a good prognostic value has been achieved with measures of radionuclide imaging. An alternative but simple procedure including influencing factors and standards of measurement is the determination of the systolic occlusion pressure. Further technical advances can be achieved by a combination of methods but this requires the systematic verification prior to their use. However, their technical potential and options appear to be not fully utilized yet.