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Biomedical subjects

N Haas

Publications and source records attributed to N Haas.

At least 37 records · Page 2Linked to original sources
PubMed2003

Less invasive stabilization system (LISS) in the treatment of distal femoral fractures.

The treatment of distal femoral fractures has been associated with a high rate of complications for a long time. Although implants and surgical techniques have improved, plate osteosynthesis and intramedullary nailing have been accompanied by a high occurrence of infection, non-union and malalignment. The treatment of soft tissue envelopes using "biological" osteosynthesis and minimally invasive approaches has resulted in a decrease in complication rates and ultimately led to the concept of the less invasive stabilization system (LISS). This is an extramedullary-applied, internal fixator shaped according to the implantation site anatomy, with minimal invasiveness. The purpose of this study was to present this new surgical technique and draw attention to its advantages and importance. Although this is not a scientific paper, we hope to provide enough evidence of the LISS usefulness. The main LISS components include multiple-fixed angle screws and an insertion handle for submuscular sliding of a fixator and placement of percutaneous, self-drilling, unicortical screws for fixation of the diaphyseal fracture fragments. The LISS has been designed to preserve periosteal perfusion and to facilitate a minimally invasive application. Since the first implantation of the LISS, only a few studies have been published on its use in treatment of distal femoral fractures. The rate of infection has been low, ranging from 0 to 4%. The rate of delayed union has been between 2.4 and 6.1%, but delayed unions do not necessarily lead to secondary bone grafting or repeat osteosynthesis as the LISS has a high and lasting stability. When the LISS is used, bone grafting is rarely necessary (0 to 1.6% in primary and 0 to 5% in secondary grafting). Also implant failure differs from the failure of plate osteosynthesis because, with the use of LISS, no screw loosening or secondary malalignment occurs. Implant failures (up to 7.4%) were recorded particularly at the time of LISS introduction in surgical practice and were attributed to the technique of implantation rather than to the implant itself. Good treatment outcomes have been reported. The average knee flexion has been 103 degrees and 107 degrees. In 72.5% of the patients, flexion has been more than 90 degrees and an extension lag of > or = 10 degrees has been found in only 7.5% of all cases. The average Neer score has ranged from 73.9 to 77.2 points. In conclusion, the LISS is a useful implant for treatment of distal femoral fractures, especially when bone quality is poor. Infection, delayed union and non-union rates are low, as shown by yet unpublished data from our clinic. Primary bone grafting, which is rarely necessary with this system, is carried out only when there is a great bone loss. Implant failure, such as screw loosening or secondary malalignment, is not seen.

Adult↗
PubMed2002

Nine-year follow-up of a case of Grzybowski type multiple keratoacanthomas and failure to demonstrate human papillomavirus.

We describe a patient with a 9-year history of generalized eruptive keratoacanthoma (KA) of the Grzybowski type whose multiple skin lesions showed steady progression, resulting in a sclerotic, mask-like facial expression and ectropion. Eleven tumour biopsies representing lesions of different stages and localizations (erupting and regressing KAs, biopsies from non-involved light-protected and light-exposed skin, dermatosclerosis and squamous cell carcinomas) were analysed for human papillomavirus (HPV) sequences using a polymerase chain reaction approach capable of detecting the majority of all presently known HPV genotypes. None of the biopsy specimens proved to be HPV-positive, although HPV was detected in weakly and heavily affected control specimens by the method applied. These findings suggest an HPV-independent aetiology of this rare type of multiple KA.

Aged↗
PubMed2002

Methicillin-resistant Staphylococcus aureus (MRSA) sepsis following mesh graft transplantation to treat chronic leg ulcer.

Infections with methicillin-resistant strains of Staphylococcus aureus (MRSA) from colonized leg ulcers are rare. We describe a case of MRSA sepsis following mesh graft transplantation to treat a chronic leg ulcer. MRSA were isolated from blood and midstream urine and typed by their antimicrobial sensitivity, phage and SmaI-macrorestriction patterns. A strain found during sepsis was identical to an epidemic MRSA related to epidemic MRSA 15 from Great Britain. Control swabs to detect MRSA should be implemented in epidemic areas of MRSA before grafting chronic ulcers.

Aged↗
PubMed2001

[A medical student discovers onychomycosis].

When G. Meissner discovered the tactile bodies of the skin, he earned early fame. Yet he made further contributions to dermatology which have been forgotten such as the first description of onychomycosis. This took place when he was still a student in Göttingen. The circumstances of this discovery are told in the context of the medical history of that time, paying special attention to certain epidemiological aspects. Finally, a detailed account is given of Meissner's academic career.

Dermatology↗
PubMed2001

[Shiitake dermatitis: flagellate dermatitis after eating mushrooms].

The name of flagellate dermatitis originates from self-flagellating medieval people. This dermatitis is not rare as a drug eruption following bleomycin therapy. An identical skin eruption caused by the mushroom shiitake Lentinus edodes is more common but reported mostly from Japan. We saw a 67-year-old patient who presented with the typical linear scratch marks after a dinner in a Chinese restaurant. The basic mechanism is a toxic epidermal damage. Since it is not clear why the dermatitis does not occur frequently since Shiitake is the second most popular mushroom in the world, we discuss possible cofactors that may trigger the toxic reaction.

Administration, Oral↗
PubMed2001

[Ernst Schweninger, personal physician of the German chancellor and director of the Charite Dermatology Clinic 1884-1902].

Ernst Schweninger was at the age of 33 years already world renowned for being Bismarck's personal physician. In 1884, his grateful patient made him chief of the Department of Dermatology in Berlin and Professor of Dermatology. The subsequent years were marked by political struggles within the university, but he still produced a number of scientific publications, and is still remember for his first description of anetoderma type Schweninger-Buzzi. Dermatology and his activities at the Berlin clinic from whose direction he resigned in 1902 accounted for only one period in his life. His main interest was the physiologic-dietetic therapeutic method which he applied also to dermatology. Later on, he dissociated himself from scientific medicine and became the founder of a school for natural healing methods. The present report is designed to keep alive the memories of this politically active physician.

Berlin↗
PubMed2001

[Keratosis lichenoides chronica following trauma. A case report and update of the last literature review].

Since the original description by M. Kaposi in 1895, 40 cases of keratosis lichenoides chronica have been published. Most have been reports of single cases. The clinical appearance is characterized by lichen planus-like papules, linear keratoses, and psoriasis-like plaques. While the etiology is still unknown, an association with a variety of diseases including hepatitis, tuberculosis, glomerulonephritis, and lymphoproliferative diseases has been reported. We present a new case which may have been triggered by trauma or carbamazepine.

Adolescent↗
PubMed2001

Treatment of diaphyseal fractures of the forearm using the Point Contact Fixator (PC-Fix): results of 387 fractures of a prospective multicentric study (PC-Fix II).

Fractures of the forearm are considered to be a very good indication for plating. Conventional plating is still technically demanding. Extensive animal studies show that there is potential for improvement. The method consists of using an internal fixator that minimizes implant contact to the bone to reduce biological damage. Furthermore, foregoing the need for precise reduction and interfragmental compression makes it easier to use and, therefore, it should be safer. The goal of the study was to observe handling qualities, healing, and complications. For this purpose the study was designed to yield a very high follow-up in clinics with adequate experience and with a number of different surgeons performing the internal fixation. The study was designed as a prospective multicentre investigation in 16 trauma centres worldwide. To test the new approach to internal fixation, diaphyseal fractures of the forearm were stabilized surgically with the PC-Fix (Point-Contact Fixator) system, namely, 387 fractured bones involving 277 forearms in 272 patients. Internal fixation was performed using 387 PC-Fixators. 21% of the fractures were open and 25% occurred in polytraumatized patients. The rate of follow-up was 97%. 355 fractured bones healed uneventfully within four months. Overall, there were 32 complications before bone union occurred; 27 of these bones required re-operation (27 of 387, 7%). All of them subsequently healed without further complications. There were 15 delayed or non-unions and seven implant loosenings, two of which were associated with infection. Two superficial (0.6%) and two deep infections (0.6%) occurred in 306 closed fractures. Deep infection developed in one of 81 osteosyntheses of open fractures (1.2%). Other complications included one synostosis, fractures with the implant in situ with adequate trauma involving three bones, and two secondary correction procedures for postoperative malalignment. There were seven refractures occurring at a mean of three weeks after the removal of 150 PC-Fixators (4.7%). This study demonstrated that the technique of using an internal fixator is a simple one for the fixation of forearm fractures, resulting in shorter duration of surgery with a low rate of complications compared with the data reported in the literature on conventional techniques for forearm fracture stabilization.

Adolescent↗
PubMed2001

Minimally invasive fracture stabilization of distal femoral fractures with the LISS: a prospective multicenter study. Results of a clinical study with special emphasis on difficult cases.

The LISS-DF (Less invasive stabilization system-distal femur) is a new type of implant system for the treatment of distal femoral fractures according to the principles of "Minimally Invasive Surgery". A plate, pre-contoured to the anatomy, is inserted through a minimally invasive incision into the epiperiosteal space by means of an aiming device after indirect, closed fracture reduction. The implant is stabilized by insertion of screws which lock into the plate holes and prevent tilting. This is performed with the aid of an aiming device and through stab incisions. It is not necessary for a large area to be exposed at the fracture site. As part of an AO prospective multicenter study, the new system was applied to 112 patients with 116 fractures. The time to follow-up was on average 13.7 months (minimum 7 months, maximum 33 months). Fractures treated were distal femoral shaft and supracondylar femoral fractures. Eight patients died during the study of causes unrelated to the implant. Of the remaining 104 patients with 107 fractures, 96 patients with 99 fractures were available for complete follow-up (93% follow-up rate). In 90% of all cases treated and followed up, the fracture had consolidated during the period of observation. Twenty-three revision operations were necessary in 21 patients. In two cases, implant failure occurred as the result of a pseudarthrosis. The complications can be attributed in nearly all cases to the severity of the trauma and/or a lack of experience when applying the new style implant to a wider range of indications. The results of the study show that with a sound knowledge of the operative technique and careful preoperative planning this system represents an excellent, safe procedure for the treatment of almost all distal femoral fracture types including periprosthetic fractures of the distal femur. There is generally no need for primary cancellous bone grafting.

Adolescent↗
PubMed2001

Phase I trial of weekly paclitaxel plus oral estramustine phosphate in patients with hormone-refractory prostate cancer.

OBJECTIVES: To exploit the favorable dose intensity and safety profile of weekly paclitaxel, we conducted a Phase I trial of paclitaxel by 3-hour infusion in combination with estramustine phosphate (EM) in men with hormone-refractory prostate cancer (HRPC). The antimicrotubule drug combination of paclitaxel by 96-hour infusion plus EM is active in HRPC. METHODS: Twenty-four patients with metastatic HRPC and progressive tumor after antiandrogen withdrawal were enrolled in this study. Oral EM was taken at a dose of 600 mg/m(2) daily for the initial 21 patients and on a reduced schedule of 280 mg twice daily for the final 3 patients. Paclitaxel was escalated from 60 to 118 mg/m(2). RESULTS: The major toxicities were gastrointestinal and thromboembolic complications related to daily oral dosing of EM. Of the first 21 patients, one third (n = 7) discontinued therapy within 4 weeks because of protracted nausea and/or thrombotic complications. Dose-limiting toxicities at 118 mg/m(2) paclitaxel were fatigue and hepatotoxicity. Of 13 patients with measurable soft-tissue lesions, 6 had objective partial regressions, and 9 (37.5%) of 24 patients (95% confidence interval 19.1% to 59.1%) with elevated prostate-specific antigen levels had a 50% or greater decline of at least 4 weeks' duration. CONCLUSIONS: Weekly paclitaxel at doses of 60 to 107 mg/m(2) were feasible in combination with oral EM, but daily oral EM produced unacceptable toxicity. On the basis of these results, a Phase II trial of weekly paclitaxel with the reduced dose and schedule of EM was initiated by the Eastern Cooperative Oncology Group to assess further the benefits and risks of this treatment in men with metastatic HRPC.

Adenocarcinoma↗
PubMed2001

Homologous growth hormone accelerates healing of segmental bone defects.

The effect of homologous recombinant porcine growth hormone (r-pGH) on secondary fracture healing was investigated in a diaphyseal defect of the tibia in Yucatan micropigs. A 1 cm defect of the tibia was created surgically and stabilized with an AO 3.5 mm DCP plate. The treatment group (12 animals) received 100 microg of r-pGH per kilogram of body weight subcutaneously once per day, whereas the control pigs (12 animals) received 1 mL of sodium chloride as placebo. For evaluation of the GH-axis, serum levels of insulin-like growth factor-I (IGF-I) were sampled every fourth day. The animals were killed 6 weeks after surgery. Quantitative computed tomography (qCT) was performed to determine bone mineral density (BMD) and bone mineral content (BMC) of the defect zone. The torsional stiffness and the torsional failure load were measured by destructive torsional testing of the defect and contralateral tibiae. qCT measurements revealed a significant increase in the BMC of the defect zone in the treatment group compared with controls (GH BMC = 2833 +/- 679 mg, placebo BMC = 2215 +/- 636 mg; p < 0.05), whereas the BMD values were similar in both groups (GH BMD = 668 +/- 60 mg/mm(2), placebo BMD = 629 +/- 52 mg/mm(2), p = 0.12). Torsional failure load was 70% higher and torsional stiffness 83% higher in the treatment group than in the control group (p < 0.05). The mean serum level of IGF-I in the treatment group increased to 382% of the preoperative basal level and decreased to 69% in the control group, and this difference was highly significant (p < 0.001). Our data indicate that daily administration of recombinant GH leads to an increase of serum IGF-I levels and stimulates secondary fracture healing, resulting in increased mechanical strength and stiffness of the callus.

Animals↗
PubMed2001

Adhesion molecules and cellular infiltrate: histology of urticaria.

Urticarial reactions are characterized by dermal capillary dilatation and edema, associated with a variably intense mixed inflammatory infiltrate consisting of neutrophils, eosinophils, T-helper lymphocytes, and activated macrophages. Mast cell numbers are moderately increased by a factor of 2.4, in contrast to mastocytosis where numbers are much higher (5-48-fold increase). In urticarial vasculitis there is in addition endothelial damage, leukocytoclasia, and fibrin and complement deposition. The emigration of leukocytes is regulated by vasoactive and chemotactic mediators released firom mast cells, inducing a sequential upregulation of endothelial adhesion molecules (P-selectin, E-selectin, ICAM-1, and VCAM-1), of beta2-integrins on leukocytes, and of cytokines on endothelial, epithelial, and infiltrating cells. In nonlesional skin, there is also an increase of mast cells and an upregulation of endothelial adhesion molecules, probably due to molecules in the circulation of which P-selectin and TNFalpha have so far been demonstrated. Whereas these data provide a molecular basis for the understanding of variations in mast cell-dependent pathology, they underline the fact that they are not diagnostic for different types of urticaria, except for urticarial vasculitis and mastocytosis.

Adult↗
PubMed2001

Treating forearm fractures using an internal fixator: a prospective study.

Some major complications of internal fixation with plates, such as infections and disturbance of healing, have been shown to be related to necrosis of bone and to the soft tissues immediately deep to the plate. This is attributable to plate contact. To deal with this phenomenon, an internal fixator, the Point Contact Fixator, was developed according to a new concept. The Point Contact Fixator resembles a plate but functions like a fixator, that is, the fracture is stabilized using a splint fixed to the bone by monocortical, angularly locked screws that are designed not to exert pressure between the splint and the bone, thereby minimizing implant-to-bone contact. Vascular damage to the osseous blood supply consequently is avoided. The new internal fixator is the first of a new family of implants in addition to nails, plates, and external fixators. To study the potential of the Point Contact Fixator in a prospective study, 79 forearm fractures in 55 patients were treated in a consecutive series by one surgeon using the same technique throughout. Followup to union is reported for 100% of the patients. Handling the fixator was simple; healing was uneventful; and the rate of complication was low.

Adult↗
PubMed2001

Acute herpes zoster neuralgia: retrospective analysis of clinical aspects and therapeutic responsiveness.

BACKGROUND: Although the efficacy of modern antiviral agents for the treatment of herpes zoster is unquestioned, their ability to affect the associated pain remains controversial. OBJECTIVE: We have therefore evaluated the inpatient hospital records of 550 patients with herpes zoster with regard to pain-related clinical aspects and therapeutic responsiveness. METHODS: Intensity of pain was quantified by calculating a daily pain equivalence index (PEI) on the basis of different classes of pain medication and the number of tablets used in each category. RESULTS: The mean age of patients was 66.7 years, cranial segments were predominantly involved (55%), 64% of patients suffered from associated diseases and 77% experienced herpes-related pain. The PEI was 0.90 in the entire patient population, with significantly higher values in women and in patients with 3 or more associated diseases. It was lower in sacral and cranial nerve involvement, and it decreased rapidly in patients prior to discharge from hospital. Although there were significant differences in hospital stay between patients who received aciclovir and those who did not (mean 20.3 vs. 23.8 days), and for high- versus low-dose oral or intravenous administration, no significant differences were noted between the two groups for initial PEI values and during the course of observation, irrespective of the route of administration or the dose of aciclovir and the individual patient's PEI value. The groups were otherwise closely similar with regard to basic demographic and clinical data. 23.3% predominantly aged female patients with more associated diseases than the total patient population had a persistently elevated PEI and stayed in hospital beyond 21 days (mean 35.1 days), representing patients who went on to postherpetic neuralgia. CONCLUSION: These data further delineate clinical aspects of acute herpes zoster neuralgia, underline the unsolved therapeutic problems associated with this condition despite otherwise effective antiviral treatment, and characterise a subgroup of patients at risk to develop postherpetic neuralgia.

Acute Disease↗