Local gentamicin application does not interfere with bone healing in a rat model.

For the prophylaxis and treatment of bony infections antibiotics are locally used. Since several decades antibiotics mixed with bone cement (methylmethacrylate) are successfully used in prosthetic surgery and a gentamicin coated tibial nail is approved in Europe for fracture stabilization. The goal of the present study was to investigate if gentamicin, locally applied from a polymeric coating of intramedullary nails, might interfere with the bone healing process. Female Sprague Dawley rats (n = 72) were used and the tibiae were intramedullary stabilized with Kirschner-wires (k-wires) after osteotomy. This model was established earlier and shows a delayed healing with a prolonged inflammatory reaction. The open approach is clinically more relevant compared to a closed one because it mimics the clinically critical case of an open fracture, which has a higher risk of infection. The k-wire was either coated with the polymer poly(d,l-lactide) (control group) or with 10% gentamicin incorporated into the polymer (gentamicin group). In vivo µCT analyses were performed at days 10, 28, 42, and 84 after osteotomy. Mechanical torsional testing and histological evaluation were done at the days of sacrifice: 28, 42, and 84. The µCT analyses revealed an increase in tissue mineral density (TMD) over the healing period in both groups. In the control group, the torsional stiffness and maximum load did not reach the values of the intact contralateral side at any time point. At day 84 the gentamicin treated tibiae, however, showed significantly better maximum load compared to the control group. The histology showed no bony bridging in the control, whereas in 2 of 5 calluses of the gentamicin group mineralized bridging occurred. Significantly more mineralized tissue was measured in the gentamicin group. This study shows that the local gentamicin application does not negatively interfere with the long term healing process. Local infection prophylaxis is effective without negative effects on bone healing.

Local inhibition of angiogenesis results in an atrophic non-union in a rat osteotomy model.

Long bone and in particular tibia fractures frequently fail to heal. A disturbed revascularisation is supposed to be a major cause for impaired bone healing or the development of non-unions. We aim to establish an animal model, which reliably mimics the clinical situation. Human microvascular endothelial cells (HMEC-1) and primary human osteoblast like cells (POBs) were cultured with different angiogenesis-inhibitors (Fumagillin, SU5416, Artesunate and 3,5,4'-Trimethoxystilbene) released out of poly(D,L-Lactide) (PDLLA) coated k-wires and cell activity was determined. Discs containing PDLLA or PDLLA + Fumagillin/Artesunate were placed at the chorionallantoic membrane of hen eggs and the effect on vessel formation and egg vitality was observed. Tibia osteotomy was performed in rats and stabilised with K-wires coated with PDLLA + Fumagillin or with PDLLA only (control group). The healing was compared at different time points to the PDLLA control. Fumagillin and Artesunate inhibited the activity of HMEC-1 with minor effect on POBs. Artesunate caused embryonic death, whereas Fumagillin had no effects on egg vitality, but reduced the blood vessels. In the animal study all rats showed an impaired healing with reduced biomechanical stability. The Fumagillin treated tibiae had a significantly decreased callus size at day 42 and 84, less blood vessels in the early callus, a reduced histological callus size at day 10, 28 and 84, as well as an altered callus composition. This study presents a less vascularised, atrophic, tibia non-union and can be used in further investigations to analyse the pathology of atrophic non-union and to test new interventions.

Local BMP-2 application can rescue the delayed osteotomy healing in a rat model.

Delayed healing is still a severe complication in the clinic. The aim of the present study was to investigate the effect of locally delivered BMP-2 incorporated in a poly(d,l-lactide) (PDLLA) implant coating in a rat model with delayed tibial healing. The healing delay in this model is not caused by mechanical instability or additional tissue manipulation and presents therefore a common and challenging clinical situation of impaired healing. Radiological, histological and biomechanical evaluations were performed at days 5, 10, 28, 42, and 84 after tibial osteotomy. The control group showed a delayed healing without complete bridging and without reaching the biomechanical stability of the contralateral tibiae after 84 days. The mechanical stability of the BMP-treated tibiae showed a significant increase at days 28 and 42 compared to the control group and exceeded the stability of the intact contralateral tibiae. Less cartilage was detected at day 28 and the mineralisation was significantly enhanced at day 42 due to the local BMP application. Looking at the early healing phase (day 10) a reduced vascularisation was seen in the BMP group. This reflects the situation seen during normal healing, whereas the delayed healing in the present model had an increased vascularisation. The present study clearly demonstrates that local BMP-2 application can stimulate delayed healing in a clinically relevant animal model.

Characterization of tendon cell cultures of the human rotator cuff.

Rotator cuff tears are common soft tissue injuries of the musculoskeletal system that heal by formation of repair tissue and may lead to high retear rates and joint dysfunction. In particular, tissue from chronic, large tendon tears is of such degenerative nature that it may be prone to retear after surgical repair. Besides several biomechanical approaches, biologically based strategies such as application of growth factors may be promising for increasing cell activity and production of extracellular tendon matrix at the tendon-to-bone unit. As a precondition for subsequent experimental growth factor application, the aim of the present study was to establish and characterize a human rotator cuff tendon cell culture. Long head biceps (LHB)- and supraspinatus muscle (SSP)- tendon samples from donor patients undergoing shoulder surgery were cultivated and examined at the RNA level for expression of collagen type-I, -II and -III, biglycan, decorin, tenascin-C, aggrecan, osteocalcin, tenomodulin and scleraxis (by Real-time PCR). Finally, results were compared to chondrocytes and osteoblasts as control cells. An expression pattern was found which may reflect a human rotator cuff tenocyte-like cell culture. Both SSP and LHB tenocyte-like cells differed from chondrocyte cell cultures in terms of reduced expression of collagen type-II (p

[Thirteen-year results for the CLS expansion cup in primary hip arthroplasty]. / 13-Jahres-Ergebnisse der CLS-Spreizpfanne in der primären Hüftendoprothetik.

BACKGROUND: Clinical studies of the CLS expansion cup in hybrid hip arthroplasty generally show good results. However, follow-up times are limited to between 5 and 10 years. The aim of our study was to assess the clinical and radiological outcome of the CLS cup after more than 10 years. MATERIAL AND METHOD: After a follow-up of 13 years (10-15 years), 41 of 186 patients with a total of 41 CLS cups were available for clinical and radiological evaluation. In addition, a digital analysis of all radiographs was done. This included measurement of the migration, inclination, polyethylene wear, shaft subsidence, and osteolytic lesions. RESULTS: The average preoperative Harris hip score was 48, which increased to 81 at final follow-up. No acetabular loosening was found. Two cups (5%) showed osteolytic lesions not exceeding 50% of the specific zone according to DeLee and Charnley and were considered stable. There was no migration or inclination of the cups. The average polyethylene wear corresponded to 0.1 mm/year. Sixteen patients (39%) showed osteolyses around the stem and were considered loose. CONCLUSION: The CLS expansion cup provides excellent clinical results after 13 years in hybrid total hip arthroplasty. Time-correlative polyethylene wear and the extremely high rate of stem loosening have no consequences for the cup stability in our patient group. Acetabular osteolysis is rare.

Cloning, sequencing, and characterization of a membrane-associated Prevotella ruminicola B(1)4 beta-glucosidase with cellodextrinase and cyanoglycosidase activities.

Prevotella ruminicola B(1)4 is a gram-negative, anaerobic gastrointestinal bacterium. A 2.4-kbp chromosomal fragment from P. ruminicola encoding an 87-kDa aryl-glucosidase (CdxA) with cellodextrinase activity was cloned into Escherichia coli DH5 alpha and sequenced. CdxA activity was found predominantly in the membrane fraction of both P. ruminicola and E. coli, but P. ruminicola localized the protein extracellularly while E. coli did not. The hydrolase had the highest activity on cellodextrins (3.43 to 4.13 mumol of glucose released min-1 mg of protein-1) and p-nitrophenyl-beta-D-glucoside (3.54 mumol min-1 mg of protein-1). Significant activity (70% of p-nitrophenyl-beta-D-glucoside activity) was also detected on arbutin and prunasin. Less activity was obtained with cellobiose, amygdalin, or gentiobiose. CdxA attacks cellodextrins from the nonreducing end, releasing glucose units, and appears to be an exo-1,4-beta-glucosidase (EC 3.2.1.74) which also is able to attack beta-1,6 linkages. Comparison of the deduced amino acid sequence with other glycosyl-hydrolases suggests that this enzyme belongs to family 3 (B. Henrissat, Biochem. J. 280:309-316, 1991). On the basis of this sequence alignment, the catalytic residues are believed to be Asp-275 and Glu-265. This is the first report of a cloned ruminal bacterial enzyme which can cleave cyanogenic plant compounds and which may therefore contribute to cyanide toxicity in ruminants.

Adverse psychic reactions to psychotropic drugs--a report from the AMUP study.

The AMUP study (AMUP = Arzneimittelüberwachung in der Psychiatrie (Drug Monitoring in Psychiatry)) was conducted from 1979 to 1989 in order to provide for a systematic and standardized assessment of all adverse reactions to psychotropic drugs under the conditions of routine clinical treatment at two psychiatric hospitals. This paper presents data from the AMUP study on the type and frequency of adverse psychic reactions to psychotropic drug groups and relevant single drugs. Psychic ADR leading to drug discontinuation were observed in 4.5% of 15,264 inpatients monitored over an eight-year period. Only neurological ADR were more frequent (4.9%). Neuroleptics and antidepressants were involved with similar frequencies in ADR that were at least "probably" drug-related (3.3 and 3.5%). Lithium salts and benzodiazepines were only rarely involved in psychic ADR. Toxic delirium (1.0%), agitation (0.9%), and sedation (0.8%) were the most frequent single events, usually rated as "probably" drug-related. Depression and psychotic states were next in frequency, but judged as only "possibly" drug-related in a considerable proportion of cases. Haloperidol, the most common high-potency neuroleptic, was imputed mainly for depression, sedation, agitation, and (malignant) neuroleptic syndrome; with medium-potency perazine, toxic delirium and sedation prevailed; among the most common antidepressants, amitriptyline was above all connected with toxic delirium, while with clomipramine agitation predominated. The paper discusses the particular difficulties encountered in the field of psychic ADR in psychiatric patients regarding causality assessment, and emphasizes the need for continuous ADR assessment studies including state hospitals.

Macrocytosis and pseudoalbinism: manifestations of selenium deficiency.

Selenium levels were low in four children receiving long-term total parenteral nutrition (TPN) who developed erythrocyte macrocytosis (3/4), loss of pigmentation of hair and skin (2/4), elevated transaminase and creatine kinase activities (2/4), and profound muscle weakness (1/4). Initial mean selenium levels in serum and hair were 38 +/- 11 (SEM) ng/mL and 0.34 +/- 0.13 micrograms/g, respectively. Mean serum vitamin B12, folate, and vitamin E levels were normal. Intravenous supplementation with selenium was begun daily at 2 micrograms/kg/day. After 3 to 6 months, serum selenium levels rose almost threefold to 81 +/- 22 ng/mL. During this same time, erythrocyte mean corpuscular volume fell from 115 +/- 8 fL to 88 +/- 7 fL in the three children with macrocytosis. After 6 to 12 months of supplementation, hair selenium content had increased threefold to 1.02 +/- 0.19 micrograms/g. The two children with decreased pigmentation became darker skinned and their hair color changed from blonde to dark brown; a third child's hair, which had been blonde, also became darker. Transaminase and creatine kinase activities returned to near normal in those affected and, in the one child with severe myopathy, muscle weakness improved. Erythrocyte macrocytosis and loss of skin and hair pigmentation are previously undescribed manifestations of selenium deficiency. We recommend routine supplementation of TPN solution with selenium to avoid the clinical and biochemical syndrome of selenium deficiency in patients receiving long-term TPN.

Primary sclerosing cholangitis associated with hyperimmunoglobulin M immunodeficiency (dysgammaglobulinemia).

Primary sclerosing cholangitis is an uncommon disorder of obliterative biliary inflammation that is exceedingly rare in childhood. Presented is a child with hyperimmunoglobulin M immunodeficiency (dysgammaglobulinemia) and primary sclerosing cholangitis. This case should focus attention on the association of primary sclerosing cholangitis and immunodeficiency syndromes, particularly in children with immune disorders and unexplained hepatic abnormalities.

Polle syndrome: chronic diarrhea in Munchausen's child.

A child with a complex history of chronic diarrhea and a seizure disorder, with multiple nondiagnostic previous evaluations, is presented. Under careful observation and with minimal diagnostic studies, the source of this child's chronic disorder was confirmed to be exogenous drug administration by the mother. Polle syndrome, a child-abuse variant of Munchausen syndrome, must be considered as part of an aberrant family social setting by adult or pediatric physicians who uncover a chronic factitious disease. More attention to psychosocial history gathering may preclude well-meaning, but unwarranted, multiple diagnostic endeavors.

Home parenteral nutrition in children with Crohn's disease: an effective management alternative.

Seventeen pediatric patients, ages 9.25--20.5 yr, were placed on a program of home parenteral nutrition (HPN) for severe, symptomatic Crohn's disease. Prior therapy with sulfasalazine in 14, adrenocorticosteroids in 12, inpatient total parenteral nutrition in 7, and/or surgical resections in 6 failed to suppress disease activity. Remission was attained in 12 of the 17 after one course of HPN alone. Four patients had surgical procedures and 1 required steroids in addition to HPN. Remissions have been maintained in 4 of those 12 for a mean duration of 315 days after discontinuation of HPN. Of the 8 who relapsed after a mean duration of 68 days, second courses of HPN were undertaken in 7 and third courses in 2. All 17 had a marked improvement in disease symptoms while receiving HPN in addition to gaining weight sufficient to place them at a higher percentile on standard growth charts. Ten patients demonstrated "catch-up" growth and 4 others increased their height appropriately. A chromium 51-labeled albumin stool collection of greater than 1% in 5 of 7 patients at the completion of a HPN course correlated with relapse within 4 mo. Serial radiographic contrast studies and erythrocyte sedimentation rates were not predictive of prolonged remissions. Home parenteral nutrition complications were minimal, with only one episode of sepsis per 5.8 catheter experience years. It is concluded that HPN is a safe and effective means of inducing remissions and providing optimal nutritional support in pediatric patients with severe Crohn's disease. Patients with less than adequate response to standard medical management should be considered candidates for this therapeutic modality.

Recurrent pulmonary disease in children: a complication of gastroesophageal reflux.

To evaluate the role of gastroesophageal reflux (GER) as a possible cause of recurrent pulmonary disease, 30 children, aged 1 to 18 years, were studied prospectively with esophageal function tests. These included esophagram (30 patients), esophageal manometry (29 patients), pH probe (Tuttle) test (29 patients), and esophagoscopy with esophageal biopsy (23 patients). The patients studied had either chronic asthma or two or more documented pneumonias within a one-year period. Nineteen (63%) had GER based on two or more positive tests. Eighteen had positive Tuttle tests; 13 had abnormal manometry studies; nine had esophagitis on biopsy; six had esophagitis on esophagoscopy; and five had reflux on esophagram. Of those with GER, 17 had a history of nocturnal cough and eight vomited during infancy. Children with recurrent pulmonary disease should have esophageal function testing to exclude GER as the cause.

Home parenteral nutrition: results in 34 pediatric patients.

Although home parenteral nutrition (HPN) has been used successfully for adult patients, no extensive experience with children has been reported. During the past three years, we have managed 34 patients, ages 1 1/2 months to 20 1/2 years, on a HPN program for periods ranging from 23 to 786 days. Silastic Broviac catheters were inserted into the superior vena cava through the jugular or cephalic veins or into the inferior vena cava through the saphenous vein. The catheters were brought out onto the chest or lower abdominal wall through a subcutaneous tunnel. Solutions were infused over a 10--14-hour period each day, using a volumetric pump system. All patients improved their nutritional status. Twenty-three of 29 on the program for more than two months showed an increase in height. All patients evidenced a significant decrease in symptomatology. All resumed per group activities while on HPN and were able to continue their education or work. At present 24 patients including 15 with Crohn's disease no longer receive HPN. Administration of HPN through a Broviac catheter is a safe, successful technique for maintaining an optimal nutritional status in children with severe digestive disorders, and permits resumption of a more normal daily lifestyle. Following HPN, bowel adaptation and initiation of full oral alimentation become possible in many patients.

A zinc-deficiency dermatitis in patients on total parenteral nutrition.

Three patients on home total parenteral nutrition utilizing a synthetic amino acid solutions developed a dermatitis consistent with acrodermatitis enteropathica after 30, 43 and 62 days of therapy. The dermatitis resolved after changing to casein hydrolysate in 2 patients and after full oral alimentation in the third. Although measured serum zinc levels were repeatedly normal to elevated in all patients, sufficient retrospective data analysis combined with literature review on this subject, clearly implicates zinc deficiency as the etiology for their dermatitis. Adequate zinc supplementation of synthetic amino acid solutions is essential in order to avoid this complication.