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Biomedical subjects

H J Buhr

Publications and source records attributed to H J Buhr.

At least 19 recordsLinked to original sources
PubMed2006

Differential expression of genes encoding tight junction proteins in colorectal cancer: frequent dysregulation of claudin-1, -8 and -12.

BACKGROUND AND AIMS: As integral membrane proteins, claudins form tight junctions together with occludin. Several claudins were shown to be up-regulated in various cancer types. We performed an expression analysis of genes encoding tight junction proteins to display differential gene expression on RNA and protein level and to identify and validate potential targets for colorectal cancer (CRC) therapy. PATIENTS AND METHODS: Amplified and biotinylated cRNA from 30 microdissected CRC specimen and corresponding normal tissues was hybridized to Affymetrix U133set GeneChips. Quantification of differential protein expression of claudin-1, -8 and -12 between normal and corresponding tumour tissues was performed by Western blot analyses. Paraffin-embedded CRC tissue samples, colon cancer cell lines and normal tissue microarray were analysed for protein expression of claudin-1 by immunohistochemistry (IHC). RESULTS: Claudin-1 (CLDN1) and -12 (CLDN12) are frequently overexpressed in CRC, whereas claudin-8 (CLDN8) shows down-regulation in tumour tissue on RNA level. Quantification of proteins confirmed the overexpression of claudin-1 in tumour tissues, whereas changes of claudin-8 and -12 were not significantly detectable on protein level. IHC confirmed the markedly elevated expression level of claudin-1 in the majority of CRC, showing membranous and intracellular vesicular staining. CONCLUSIONS: Differential expression of genes encoding claudins in CRC suggests that these tight junction proteins may be associated to and involved in tumorigenesis. CLDN1 is frequently up-regulated in large proportion of CRC and may represent potential target molecule for blocking studies in CRC.

Aged↗
PubMed2006

Can laparoscopically assisted sigmoid resection provide uncomplicated management even in cases of complicated diverticulitis?

BACKGROUND: Laparoscopically assisted sigmoid resection has become an accepted method for treating uncomplicated diverticulitis. This prospective study aimed to compare the results of laparoscopic sigmoid resection for uncomplicated and complicated sigmoid diverticular disease used to check the indication for the complicated stages of diverticulitis. METHODS: All patients who underwent laparoscopic resection for sigmoid diverticulitis at the authors' hospital between 1999 and 2005 were divided into two groups: group 1 (uncomplicated diverticular disease) and group 2 (complicated diverticular disease). The exclusion criteria specified generalized peritonitis, signs of sepsis, and extensive previous abdominal surgery. RESULTS: Of the 203 patients (108 men and 95 women) who underwent laparoscopically assisted resection during the examination period, 112 were assigned to group 1 and 91 to group 2. Differences in favor of group 1 were found for the duration of surgery (154 vs 166 min), the conversion rate (1.8% vs 9.9%), the postoperative wound infections (2.7% vs 13.2%), and the postoperative hospitalization period (12.3 +/- 3.9 vs 15.0 +/- 5.6 days). No significant differences were seen in any other areas such as completion of nutritional buildup (4.6 vs 5.0 days) or time until the first postoperative bowel movement (2.8 vs 3.3 days). Total postoperative morbidity (16.1% vs 26.4%; p = 0.10) tended to be increased in group 2, but this difference was not statistically significant. CONCLUSIONS: Laparoscopic sigmoid resection can be performed for patients who have complicated diverticulitis without significantly increasing their overall morbidity. This group of patients could benefit from the advantages of the minimally invasive procedure despite a longer operating time and a higher conversion rate.

Adult↗
PubMed2006

[Results of multivisceral resection of primary colorectal cancer].

BACKGROUND: In about 10 % of all patients with colorectal cancer, the primary invention already discloses adhesions or infiltration of adjacent organs. En bloc resection of the tumor-bearing bowel segment with adjacent organs is done to give patients a chance for curation, since intraoperative differentiation is not possible. The aim of this study is characterization of the patient population as well as evaluation of the morbidity and mortality associated with this type of extensive intervention. METHOD: Between 1/95 and 6/04, we analyzed all patients with progressive primary colorectal cancer, who underwent multivisceral surgery with en bloc resection of at least one other organ. The target parameters were tumor characteristics as well as postoperative morbidity and mortality. RESULTS: A total of 1 001 patients with colorectal cancer underwent surgery. 101 patients (10 %) required multivisceral resection. In 17 % the indication was exigent. About 70 % of the interventions involved the colon. Tumor perforation was seen in 17 % of patients with colon cancer and 16 % with rectal cancer. Resection of the inner genitals was most frequent in both colon and rectal cancer (26 and 84 %) followed by small bowel resection (21 %) and partial bladder resection (19 %). Other organs play a secondary role in rectal cancer while partial bladder resection (20 %) and abdominal wall resection (14 %) is observed more frequently in colon cancer. Resection of parenchymatous organs (kidney, suprarenal gland, spleen, pancreas, liver) and others like the stomach is quite rare in colon cancer. Actual tumor infiltration (T4 situation) was observed in 51 % of patients with colon cancer and in 64 % of those with rectal cancer. Local R0 resection (97 vs. 96 %) was successfully performed in nearly all colon and rectal cancer patients. The surgical major complication rate was 9 % in colon cancer and 19 % in rectal cancer. The mortality rate was 4 %. CONCLUSION: Multivisceral en-bloc resection enables local R0 resection in the majority of cases with primary colorectal cancer. Despite sometimes extensive surgery, this type of procedure is associated with an acceptable morbidity and mortality. Since long-term survival is comparable to that in the T category (T3 or T4), multivisceral en-bloc resection is not only justified but also absolutely required in interventions with curative intention.

Abdominal Wall↗
PubMed2005

[Nonoperative ablation for liver metastases. Possibilities and limitations as a curative treatment].

Under the term "nonoperative ablation" are grouped a number of heterogeneous approaches for the treatment of liver metastases, including laser-induced thermotherapy (LITT), radio-frequency therapy (RF), and cryotherapy. In general these procedures had been intended only for palliative purposes. The establishment of clinically relevant lesion size and a lack of long-term survival data were regarded as main limitations to using them with curative intention. During the last years however, new application systems have demonstrated remarkable results in RF and LITT, and some clinical studies have shown long-term survival in selected patients comparable to that for hepatic resection. We review possibilities and limitations of nonoperative ablation procedures with curative intent, highlighting the histopathological bases of thermal ablation techniques and clinical aspects such as R0 ablation and long-term survival.

Animals↗
PubMed2005

[Emergency management of thoracic trauma].

Thoracic injuries are a major cause of mortality during the "golden hour" of trauma. Many patients with chest trauma die after reaching the hospital. Less than 10% of all blunt thoracic injuries require a thoracotomy, and many potentially life-threatening conditions can be relieved by simple procedures, such as chest tube insertion.Thus, many cases of traumatic deaths due to chest injury may be prevented by prompt diagnosis and a standardized therapeutic approach in the emergency room. A high index of suspicion for lethal injury patterns, based on the mechanism of trauma and the clinical presentation, is a crucial prerequisite for an adequate initial assessment and management of patients with chest trauma. The worldwide implementation of standardized diagnostic and therapeutic guidelines, such as the "Advanced Trauma Life Support" (ATLS) protocol, has led to a significant reduction of early deaths attributed to thoracic injuries.

Adult↗
PubMed2005

Colon perforation in an adolescent after short-term diclofenac intake.

Chronic intake of non-steroidal anti-inflammatory drugs (NSAIDs) has been reported to cause side-effects distal to the duodenum. These include strictures, diaphragm-like lesions and perforations of the small and large intestines. This is the first case report on colon perforation occurring in an adolescent (16-year-old girl) after short-term diclofenac intake.

Adolescent↗
PubMed2005

Improvement in 5-fluorouracil (5-FU) and 5-fluoro-2'-deoxyuridine (FdUrd) concentration by 5-fluorouracil-polyethylene-glycol-liposomes in abdominal stop-flow: treatment of VX2 liver-tumor-bearing rabbits.

The application of liposome-encapsulated cytostatics results in higher concentrations in tumor tissue. This effect can be further increased by blood flow retardation with longer retention time in the tumor and by arterial administration. In abdominal stop-flow therapy, a separate partial circulation with a defined flow is realized via a roller pump under hypoxic conditions. Forty chinchilla rabbits with VX-2 liver tumors were treated either intra-aortally (stop-flow therapy) or systemically with 50 mg 5-FU or 5-FU-PEG liposomes. During therapy, pH and pO2 were measured at regular intervals. After 20 minutes, concentrations of 5-FU and its metabolite FdUrd were determined by HPLC in different organs and the liver tumor. Compared to the i.v. application of monosubstances, the combination of i.a. 5-FU-PEG liposomes and flow retardation increased the concentration in tumor tissue by a factor of 44 and even 100-fold in the para-aortal lymph nodes (LN). The concentration of 5-FU and FdUrd was increased by flow reduction, intraaortal application and liposomal encapsulation of 5-FU.

Animals↗
PubMed2004

Intra-aortal therapy with 5-fluorouracil- polyethylene glycol stealth liposomes: does the metabolism of 5-fluorouracil into 5-fluoro-2'-deoxyuridine depend on ph value?. An animal study in VX-2 liver tumor-bearing rabbits.

BACKGROUND: The application of liposome-encapsulated cytostatics results in higher concentrations in tumor tissue. This effect can be further increased by blood flow retardation with longer retention time in the tumor and by arterial administration realized in abdominal stop-flow therapy, a separate partial circulation with a defined flow under hypoxic conditions. The pH changes under stop-flow therapy may affect the further metabolism of 5-fluorouracil (5-FU), used here. METHODS: The in vitro 5-fluoro-2'-deoxyuridine (5-FUrd) concentrations at increasing pH values were measured using liposomal encapsulated and free 5-FU. Subsequently, 20 chinchilla rabbits were treated intra-aortally with 5-FU or 5-FU-polyethylene glycol (PEG) liposomes. The pH value was maintained in the physiological range by continuous NaHCO3 application. After 20 min, concentrations of 5-FU and its metabolite 5-FUrd were determined in different organs, the perfusate, serum and the VX-2 tumor by HPLC. RESULTS: The in vitro 5-FUrd concentrations, which occur only in the physiological pH range, were doubled by the use of 5-FU-PEG liposomes. In the animal trial, NaHCO(3) titration doubled the 5-FUrd concentrations found in our preliminary studies. Compared to free 5-FU, 5-FU-PEG liposomes significantly increased the concentrations in the VX-2 liver tumor by 6.6-fold and in the para-aortal lymph nodes by 8.76-fold. CONCLUSION: The metabolism of 5-FU into its active metabolite 5-FUrd depends on the pH value and can be modulated. 5-FUrd concentrations can be approximately doubled with the intra-aortal application of 5-FU-PEG liposomes compared to free 5-FU.

Animals↗
PubMed2003

Persistent left superior vena cava: a reason for pseudodisplacement of a port catheter.

Port catheters have been increasingly used in recent years. Using one case as an example, we demonstrate how an anatomic variation can easily become a pitfall when inserting a central venous catheter, port catheter, pacemaker or Swan-Ganz catheter. We report a case of persistent left superior vena cava, the most common variation in the thoracic venous system. Since these procedures are increasingly being performed, surgeons, anesthesiologists and radiologists should be aware of the possible anatomic variations.

Catheterization, Central Venous↗
PubMed2003

[The importance of diagnostics in faecal incontinence. Endosonography].

Endoanal sonography is a well established method for the morphological diagnosis of anal sphincter damage. The best images are obtained using a 7-10 MHz rotating rigid endoprobe. The internal anal sphincter and the external anal sphincter, as well as the other pelvic floor structures, can be clearly visualised with this technique. Endosonography has shown physiological differences in sphincter anatomy and brought new insights into the pathogenesis of anorectal disorders. Apart of anal fistulas, faecal incontinence represents the main indication for the use of this method. In addition, rectal evacuation disorders are an indication for which endosonography allows a first step towards a diagnosis. Anal ultrasound is a technique friendly to both the physician and the patient, and belongs in every coloproctological unit for the assessment of faecal incontinence. Accuracy, specificity and sensitivity for the detection of anal sphincter defects range between 83 and 100% in almost all studies. Additional methods are vaginal endosonography, three dimensional endosonography and perineal sonography.

Adult↗
PubMed2003

[Biofeedback in faecal incontinence].

Biofeedback training is a well established method for the treatment of faecal incontinence. Prior to any biofeedback training program, a definitive diagnostic study is essential. Idiopathic faecal incontinence is the main indication for biofeedback training. Additional indications are a menacing faecal incontinence after deep anterior rectal excision with restoration of the rectal reservoir by an ileoanal pouch, anal sphincter reconstruction, rectopexy and rectocele repair. Only four studies provide evidence-based medical criteria. These, as well as numerous uncontrolled studies, show the effectiveness of biofeedback training for the treatment of faecal incontinence. Electrical stimulation of the anal sphincter is only shown to be effective in one controlled study in which it was combined with biofeedback training.

Anal Canal↗
PubMed2003

[Diagnostics and surgical therapy of enteric intussusception in adults illustrated by three cases].

The diagnosis of enteric intussusception is rare in adults but not in children. The clinical picture often takes an insidious course. Acute abdomen may also be caused by enteric intussusception. We report on three patients with enteric intussusception and acute abdomen. In two cases, a CT led to the diagnosis of invagination of the small intestine. In one patient, invagination of the terminal ileum was detected during coloscopy. All patients were submitted to limited segment resection and end-to-end anastomosis. In all three cases, the invagination was caused by benign pathological changes. Enteric intussusception in adults always requires surgery. In more than 95% of the cases, pathological findings are obtained intraoperatively, which are benign in the small intestine in 85-95% of the cases.

Adult↗