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Biomedical subjects

G Benz

Publications and source records attributed to G Benz.

At least 19 recordsLinked to original sources
PubMed2006

Experimental studies of lateral stress to transverse fractured femora treated with external fixation.

As part of a postmortem research project 9 beagle femora were dynamically tested by means of three-point bending. The test device was a spring driven impactor with an impact velocity of 3 m/s. Maximum bending force, deflection and force-deflection history were documented. After the impact transverse fractures were observed in 6 specimens, while another 3 specimens showed short oblique fractures. The fractured femora were treated realistically with external fixation (triax monotube) and again loaded on the impactor. After this treatment of the specimens and dynamic loading comminuted fractures occurred. In 7 cases all 4 pins were distorted. While there was only a small difference between the mean bending force of 751.01 N before and 729.54 N after treatment, a significant difference in terms of deflection and bending stiffness showed with p = 0.0039 for both parameters. This experimental result means that in cases of transverse fractures caused by ventral force only 9.6 % of the initial bending stiffness is obtained after stabilization with external fixation. Considering the fact that the use of external fixation protracts the time to bone consolidation of transverse fractures, this method cannot be designed as the therapy of choice.

Animals↗
PubMed2004

[Multiprobe FISH for enhanced prediction of recurrent bladder cancer].

The early detection of recurrent urothelial cancer is a great challenge for both urologists and pathologists. Cytology is a sensitive and highly specific tool for the diagnosis of high-grade bladder cancer and carcinoma in situ, but is not reliable in low-grade tumors. Therefore, cystoscopy has remained the gold standard for surveillance after resection of bladder cancer. Recent data suggest that multi-target fluorescence in situ hybridization (FISH) can markedly improve the sensitivity of urinary cytology. The goal of this study was to investigate the utility of the recently developed FISH assay Uro-Vysion for the prediction of recurrence during surveillance. 134 bladder washes obtained during a negative follow-up cystoscopy from 127 patients were analyzed. Positive cytology was strongly associated with subsequent recurrence, emphasizing the importance of conventional cytology for bladder cancer surveillance. A positive UroVysion FISH test significantly predicted recurrence when cases with rare tetraploic cells were considered as negative. Taken together, both cytology and FISH help to better determine the risk of bladder cancer recurrence in order to establish more individualized follow-up schemes.

Cystoscopy↗
PubMed1998

[Improved continence after Pena operations in anorectal abnormalities].

Studies investigating the functional outcome after operative treatment of high and intermediate forms of anal and rectum atresia have shown better results for the Pena procedure than for other forms of pull-through procedures. Follow-up with three-dimensional vector volume manometry of patients operated on according to Pena and matched controls demonstrated a significant improvement in the radial asymmetry index over the years and must be interpreted as a maturation process of the continence organ on a critical level.

Anus, Imperforate↗
PubMed1996

Proteus syndrome associated with a sacrococcygeal teratoma; a rare combination.

We report on an 5-year-old boy with a Proteus syndrome known since his second year of life. Hidden in a lipomatous tumor we excised a sacrococcygeal teratoma which must have been present since birth. This is the first case, out of about 50 published Proteus cases, of a patient with Proteus syndrome and sacrococcygeal teratoma.

Bone Neoplasms↗
PubMed1994

[Neutropenic typhlitis: a frequently missed complication of aplasia-inducing tumor therapy with a possible association to the combination of etoposide with high-dose cytosine-arabinoside].

Neutropenic typhlitis (NPT) was observed in 4 of 5 adult patients with acute leukemia treated with etoposide (VP16; 100 mg/m2/d for 6 days) and high-dose cytosine-arabinoside (HD ARAC, 2 g/m2 twice daily for 6 days) in a period of 11 months. One additional patient developed NPT after combination therapy with amsacrine (mAMSA, 120 mg/m2/d for 5 days) and etoposide (80 mg/m2/d for 5 days) during the same period. These 5 cases of NPT meant a drastic rise in the incidence of NPT at our institution, where a careful retrospective review of the charts of the 128 adult patients with leukemia treated during the preceding 5 years revealed only one case of NPT. Nonsurgical treatment led to recovery in all cases. No recurrence of NPT was observed during 3 further courses of aplasia with the use of selective (2 patients) or complete (1 patient) bowel decontamination. Etoposide may potentiate the gastrointestinal toxicity of high-dose cytosine-arabinoside with a higher incidence of NPT.

Acute Disease↗
PubMed1994

Ileitis hyperplastica follicularis Golden: surgical or conservative treatment?

The authors report on four cases of Golden's syndrome, a rare disease with unknown etiology and controversial therapy. The first two 7-year-old boys had gastrointestinal bleeding; their hemoglobin levels were 7.0 g% and 7.3 g%, respectively. A blood transfusion was required. Both patients underwent gastroscopy and rectoscopy, and no source of bleeding was found. Biopsies were taken during laparotomy, after terminal ileotomy in case one and coecotomy in the other. Bowel resection was not necessary in either case. The third and fourth boys (5 and 6 years old, respectively) were treated conservatively with parenteral nutrition; blood transfusion was not necessary. All four patients recovered within several days. Control colonoscopies 6 months later showed normal mucosa. The authors discuss their diagnostic and therapeutical regime, stressing that in their experience, this rare disease does not require surgical intervention.

Child↗
PubMed1994

Bioresorbable pins and screws in paediatric traumatology.

Bioresorbable implants are suited to the treatment of joint and shaft fractures in children. These conclusions were drawn from clinical and experimental investigations at the University of Heidelberg. Since 1990 13 fractures, including 5 medial malleolus fractures, 2 retropatella flake fractures, 1 metacarpal fracture, 2 lateral condyle, 2 epicondyle fractures and a secondary dislocated forearm fracture were treated with BIOFIX pins. 11 of these cases were without complications. There was one case of infection, and due to material failure the stability was insufficient in one case. In a post-mortem study torsional fractures were produced in femora of children between 5 and 15 months. The fractures were then fixed with one resorbable screw and put under torsional loading until the bone refractured. The post-fixation force (torsional) amounted to 77% of the original fracture force, and the degree of rotation at fracture was post-fixation 84% of the original. The stability of bioresorbable screws in the treatment of femoral spiral fractures in children can therefore be confirmed.

Ankle Injuries↗
PubMed1993

A biomechanical study of bicycle helmets' effectiveness in childhood.

The authors present the results of a series of impact tests on pedal cycle helmets. 10 helmets were tested using a drop test under three different test conditions: Left frontal/temporal from 1 m, right frontal/temporal from 1.5 m and left occipital from 1 m. Impact force and the acceleration of the headform's centre of gravity in three axes were measured. As a result of the authors' field research on pedal cycle helmets in Australia the 1.5 m drop height was considered to be more representative of a "real" accident than the less severe 1 m height fall. The range of resultant maximal accelerations, 1 m drop height, was 81 g to 193 g; 1.5 m drop height 122 g to 209 g. In comparison a fall without helmet from 0.5 m produced a maximal resultant acceleration of 282 g. Head injury criteria values were for 1 m drops between 201 and 630; from 1.5 m 547 to 1078; and without helmet from 0.5 m 906. The individual helmets are compared on these figures and their merits discussed.

Adolescent↗
PubMed1993

Late-onset 3 beta-hydroxysteroid dehydrogenase deficiency with virilization induced by a large ovarian cyst.

A midpubertal girl presented with secondary amenorrhea and a rapidly progressive deepening of her voice as the only signs of virilization. Diagnostic work-up yielded an extremely elevated plasma testosterone (289 ng/dl), low estradiol (29 pg/ml) levels and a large solitary cyst of the right ovary, which was totally removed. Pathohistology was in keeping with a granulosa cyst with mild luteinization. Normalization of testosterone (to 27.3 ng/dl) and estradiol (to 62 pg/ml) and resumption of regular menses after 2 months clearly indicated an autonomous function of the cyst. A malignant tumor was unequivocally excluded. Basal and ACTH stimulated levels of adrenal androgens pointed to a late-onset 3 beta-hydroxysteroid dehydrogenase deficiency, which per se is known to induce polycystic ovarian changes, but to date has never been described to be accompanied with a large and autonomous follicular cyst.

3-Hydroxysteroid Dehydrogenases↗
PubMed1992

[Morphometric analysis of the vascular tree of fetal tubular bones in an experimental model].

The area of interest for the longitudinal growth is the distal growth plate. In a postmortem study we were interested in changes of the epiphyseal vascular length density after fracture and surgical therapy of foetal and neonatal femora (25th to 40th post conceptional weeks). We formed three groups of equal size. Group A (25 femora) was the control group. In group B and C we performed fractures in the middle third of the femora, in group C the femora was operated with a plate afterwards. A microangiography of all femora occurred and after plastination transparent slices were produced. In this manner we could study the epiphyseal vessels in the growth plate. Using image analyses we could show that vascular density of the epiphyseal growth plate could be verified only through fracture but not by surgical therapy. The integrity of the distal epiphyseal vascular architecture is the aim after all.

Arteries↗
PubMed1992

Does lateral bending lead to bowing fracture in an infantile lower arm?

In a postmortem study on 50 lower arms of fetuses of the 25th week of gestation and newborn we performed three-point bending experiments to find out the stability of the lower arm after bending to the resulting fracture. Lower arms with intact soft tissue show an elastic behavior when bent from the side until fracture occurs. Applying the loading deflection diagrams we could classify the fractures into three types which differ significantly by means of bending moment, maximal deflection per unit length, and force required.

Biomechanical Phenomena↗
PubMed1991

[Concurrent vascular injuries in fractures in childhood].

Ten-year-analysis of blood vessel lesions present in eleven children with bone fractures revealed two major localizations: 1. In the lower extremity we observed vascular lesions in both open and closed fractures of femur and tibia. In cases with (complete) ischemia emergency operation had to be performed. 2. In the upper extremity the prevalent fracture localization was the supracondylar fracture of the elbow. Incomplete ischemia present in fractures with severe dislocation (Felsenreich III) could be salvaged by closed reposition and transcutaneous fixation by means of Kirschner wires. In those few cases open reposition was necessary, both exposure of vessels and fixation of the fracture was possible when medial incision was performed. Postoperative evaluation of patients included angiography (DSA) and ultrasound (Doppler).

Adolescent↗
PubMed1991

Rare ovarian tumors in childhood.

Between 1972 and 1990 44 patients with ovarian tumors were treated at the Department of Pediatric Surgery of the University of Heidelberg. 27 patients (61%) suffered from tumor-like lesions: neonatal, pubertal (functional) cysts, and cysts in case of syndromes. 17 genuine tumors were found (39%): 8 germ-cell tumors, 7 cystomas respectively cystadenomas and 2 tumors of the gonadal stroma. Malignancy has been observed only in two cases: 1 malignant teratoma and 1 malignant granulosa-theca-cell tumor. 2 tumor-like lesions were caused by syndromes: Albright-McCune-Sternberg- and Stein-Leventhal syndrome: Treatment of uncommon tumors depends on their size, hormonal activity, on the syndromes with which they are associated, and on the tumor status.

Child↗
PubMed1991

Inflammatory cellular infiltrates in melanocytic nevi.

We examined 1,054 melanocytic nevi [137 (13%) simple lentigines, 158 (15%) junctional nevi, 337 (32%) compound nevi, and 422 (40%) dermal nevi] for the presence of lymphohistiocytic infiltrates. The following criteria were evaluated: age and sex of the patient, location, histological type, horizontal and vertical diameter, increase of melanocytes in the basal layer of the epidermis, increase of melanophages in the papillary dermis, melanin content of keratinocytes, and melanin content of nevus cells. Lymphohistiocytic infiltrates were measured semiquantitatively; their presence within the center, in the lateral margins, or both was also determined. The results were analyzed statistically by means of chi-square tests and univariate and multivariate analyses. We found that 824 lesions (78%) were associated with a lymphohistiocytic infiltrate; whereas 230 (22%) were not. This infiltrate was weak in 273 cases (33%), moderate in 411 cases (50%), pronounced in 130 cases (16%), and very strong in 10 cases (1%). Multivariate analyses revealed that the only criteria associated with the presence of lymphohistiocytic infiltrates were the increase of melanocytes in the basal layer and the vertical thickness in compound nevi. All other parameters were statistically insignificant. We conclude that melanocytic nevi with a junctional hyperplasia of melanocytes--i.e., mostly early stages such as simple lentigines, junctional nevi, and superficial compound nevi--are often associated with a moderate to pronounced cellular stromal reaction. Their presence may reflect the appearance of antigens on proliferating melanocytes. It may also represent a stromal reaction to necrotic tumor cells and keratinocytes within the dermoepidermal junction. These findings rule out any relationship to an increase of melanin pigment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Familial colonic polyposis and malignant transformation: preventive colectomy in childhood?].

Familial polyposis coli is a classical premalignant disease. Malignancy has been observed as early as the 2nd decade of life. The probability of the development of colorectal cancer rises with age. The problem of prophylactic colectomy in childhood and adolescence is discussed using the example of two sisters whose father died of colorectal cancer at the age of 32.

Adenomatous Polyposis Coli↗
PubMed1990

[Tumors of the ribs in children].

We here present a review of ten pediatric patients with rib tumors that were treated in our hospital since 1970: a juvenile bone cyst, an aneurysmal bone cyst, an eosinophilic granuloma, a Ewing sarcoma, a metastasis of a neuroblastoma, an osteochondroma, a hemangiopericytoma, and a callous tumor at the site of a previous single rib fracture. The relative frequency of rib tumors is similar to that of bone tumors in other locations. A biopsy of the affected bone should be the first step of the operative intervention. As demonstrated in a case of eosinophilic granuloma, the indication for subperiosteal rib resection can be defined generously. A completed regrowth of the rib defect can be expected. Even the loss of a complete rib is generally well tolerated, as shown in an infant with an aneurysmal bone cyst, a rare disease in this age group. Malignant tumors of the chest wall, however, require special experience in thoracic surgery and necessitate close interdisciplinary cooperation. Complete primary resection of a malignant rib tumor and its plastic reconstruction is demonstrated in a case of a Ewing sarcoma in childhood. In children and adolescents a vicryl net should generally be used to reconstruct extended chest wall defects reliably and functionally stable.

Bone Cysts↗
PubMed1990

[An unusual case of chronic intestinal pseudo-obstruction].

A 10 year old girl developed a skin exanthema and an ileus after ingestion of a great number of elastic bands. The girl was never seriously ill before. She underwent at two different times a laparotomy each of one showing no mechanical obstructions. The bowel was distended and inflammatory processes were detected on the serosa. The proximal jejunal loops were adherent to each other and the whole bowel was adynamic. The histological findings showed a muscle necrosis of the tunica muscularis propria (longitudinal layer). Two months later the girl died on therapy resistant chronical intestinal pseudoobstruction. The autopsy showed the above mentioned muscle necrosis without vacuoles in the tunica muscularis beginning from the stomach till the anus. After consideration of the clinical, laboratory and patho-anatomical findings we think that this is a case of parainfectious visceral leiomyositis.

Child↗