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Biomedical subjects

M Walz

Publications and source records attributed to M Walz.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Differential diagnostic evaluation of a dysfunctional kidney transplant by magnetic resonance tomography].

Immediate diagnosis of rejection is essential for the prognosis of a renal transplant. To differentiate between rejection and acute tubular necrosis, 48 examinations (31 patients) were evaluated by Magnetic Resonance Imagining and Duplex Doppler ultrasound, and compared to the clinical outcome and histology. Sensitivity of MRI and Duplex Doppler was 82% (14/17), specificity was 77% (24/31) and 84% (26/31), respectively. Even when the results of both methods matched well, due to the extensive financial and technical efforts MRI may only be used as an additional tool for diagnosis.

Adult↗
PubMed1994

Expression studies with the bidirectional pcbAB-pcbC promoter region from Acremonium chrysogenum using reporter gene fusions.

Two cephalosporin genes from Acremonium chrysogenum, pcbAB and pcbC encode the ACV (alpha-aminoadipyl-cysteinyl-valine) synthetase and isopenicillin N-synthetase, respectively. The two adjacent genes are orientated in opposite directions on the chromosomal DNA, separated by a 1.2-kb non-translated sequence, carrying the putative promoter sequences. Complete sequencing of this intergenic region revealed differences from homologous sequences from other strains. To assess the putative promoter strength, we constructed an expression vector carrying the beta-glucuronidase (gusA) and beta-galactosidase (lacZ) genes in opposite orientation. Fusion of the pcbAB-pcbC promoter region resulted in recombinant vector molecules, which were used for in-vivo expression studies. Using the co-transformation procedure, the reporter gene fusions were transferred into A. chrysogenum recipient strains together with vector pMW1. Individual transformants were used for protein preparations to measure specific activities of the enzymes coded by the reporter genes. The data provide in-vivo evidence that the pcbC promoter is at least five times stronger than the pcbAB promoter. Our approach should prove useful in evaluating regulatory sequences that govern gene expression in A. chrysogenum.

Acremonium↗
PubMed1994

[Bilateral hip joint endoprosthesis: the time interval as a prognostic parameter?].

In 10-20% of patients undergoing total hip replacement bilateral replacement is necessary. This is usually done in two stages. The aim of our study was to investigate the influence of the interoperative period in bilateral hip replacement. We performed a retrospective study of 96 patients in whom bilateral hip replacement had been performed between 1974 and 1984; 72 of these patients were followed up. Assessment on follow up was based on a mobility scale, the survival time of the first prosthesis implanted was elicited from all patients. Consideration of mobility of the patients and survival time of the first prosthesis implanted revealed that the best results were obtained with an interoperative interval of between 1 and 3 years. When the interval had been shorter the mobility was less good, while patients with an interoperative period of more than 3 years had progressively less good mobility and shorter survival times of the first prosthesis. Although the range of indications for total hip replacement is not influenced by these results, the indications for replacement of the contralateral hip must be reconsidered in view of the importance of the interoperative interval.

Activities of Daily Living↗
PubMed1993

Targeted integration into the Acremonium chrysogenum genome: disruption of the pcbC gene.

The cephalosporin C-producing fungus Acremonium chrysogenum was transformed to hygromycin B resistance using different vector constructs. These constructs contain sequences of the pcbC gene from A. chrysogenum, encoding isopenicillin N synthetase. Detailed analysis of transformants, including pulsed-field gel electrophoresis (PFGE), suggests that integration of multiple vector copies takes place predominantly via non-homologous integration. By increasing the length of vector-DNA homologous to genomic DNA, integration occurs more frequently into chromosome VI, carrying the endogenous pcbC gene copy. In gene disruption experiments, the length of vector homology required to obtain cephalosporin C-minus transformants was investigated. Inactivation of the pcbC gene was observed only when homologous fragments of more than 3.0 kb were used on both sites of the resistance cassette. Southern analysis indicated homologous, as well as heterologous, integration of recombinant DNA. The integration of multiple vector copies leads to the appearance of truncated pcbC transcripts.

Acremonium↗
PubMed1993

[Compensation behavior after fractures of the thoracic and lumbar spine in children and adolescents].

UNLABELLED: Spinal column trauma with a fracture of the breast and lumbar spine is with 2-3% relatively uncommon in the pediatric patient population (from birth-16 years). In a review of 22 patients (7-15 years old) treated between 1978-1988 the individual management of treatment is reported. The goal of our study was to describe the absolute indications for the operative treatment and the difference between conservative and operative procedure depending on the age of the patient. The follow-up study after an average of 7 years and 8 months demonstrated an improvement of the neurological status (neurological status of Frankel) of 8 patients and a spontaneous correction of kyphotic angle from 21 degrees after treatment to 3 degrees. THE CONCLUSION: The treatment must be individual and depends on the age of the patient.

Adolescent↗
PubMed1993

[Ultrasonographic monitoring of conservative-functional treatment of rupture of the Achilles tendon].

Rupture of the Achilles tendon has become more common in recent years. Operative repair is the treatment generally used but non-surgical therapy is being accepted by an increasing number of surgeons because of the reports of good results with conservative treatment. Ultrasonographic examination not only allows an exact diagnosis to be made in muscle and tendon injuries, but also observation of the healing processes. Therefore, conservative functional treatment of rupture of the Achilles tendon can be used with more success, which is a very comfortable concept for these patients. We present a series of 22 subcutaneous ruptures of the Achilles tendon treated non-operatively to emphasize the value of conservative functional therapy with ultrasonographic monitoring. After immobilization of the lower leg by a walking cast in the equinus position for 3-6 weeks, the functional treatment follows using a decreasing heel lift and physiotherapy. Ultrasound examinations were performed frequently to recognize new diastasis early. We observed complete healing in all patients, absence of complications and excellent functional results. The morbidity of the patients was lower than with operative treatment and no hospital stay was needed. In conclusion, in our opinion ultrasound-controlled conservative functional treatment of rupture of the Achilles tendon should be used more frequently in future.

Achilles Tendon↗
PubMed1992

[Continuously alternating prone and supine positioning in acute lung failure].

Acute respiratory failure is still one the main problems in surgical intensive care. Unknown pathophysiological mechanisms permit only symptomatic therapy. Today ventilatory strategies by using PEEP und IRV are established to improve gas exchange and FRC by recruiting collapsed alveoli, decreasing intrapulmonary shunting and returning V/Q matching to normal. Furthermore different studies have shown the effects of supine and lateral decubitus posture in patients with acute respiratory failure. There are only rare reports on using the prone position, which doesn't require two-lung ventilation in difference to lateral position. We have studied 16 patients with acute respiratory failure by using continuous changing between prone and supine position under mechanical ventilation. All were male, aged 41.3 years in the middle and showed an average "Injury Severity Score" of 30 (13-50). 15 were trauma patients with blunt chest trauma in 11 cases. We have used prone position on threatening or manifest ARDS. In all patients we observed an increment of PaO2 during prone position on to 48 mmHg so that FiO2 could be reduced on an average of 0.2 within the first 48 h since changing patient's position. Posture changing depends on blood gas analysis, specifically on decreasing PaO2 after previous increment. Patients remained in prone and supine position at a mean of 6.3 (4.5-20) h and posture changing was proceeded over a period of 15.4 (7-32) days. No problems recording to blood pressure or mechanical ventilation appeared during prone position. 11 of 16 patients survived (68.8%), 5 died of cardiac (2) and multi organic failure (3) in connection with sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[A cellular quantitative immune deficiency in chronic post-traumatic osteomyelitis].

The specific cellular host defence in patients with chronic post-traumatic bone infection was analyzed in a prospective study. The study included 120 patients with chronic post-traumatic osteomyelitis and 60 healthy volunteers. The number of CD-5, CD-4, CD-8, natural killer cells and the CD-4/CD-8 ratio were significantly decreased. The immunodeficiency seems to be trauma-induced and reinflammation seems to be due to other immunodeficient factors. The potential key role of a defect in cytokines is discussed.

Adolescent↗
PubMed1992

[Malposition of healed distal radius fracture. Indications, technique and timing of correction].

Typical complications of distal radius fractures include post-traumatic malalignment in about 20%. This is associated with ulno-carpal pain and impaired wrist function. Various corrective procedures have been recommended. Between 1972 and 1986, 96 patients with posttraumatic disorders after distal radius fractures underwent surgical treatment. Three different procedures were carried out: simple corrective osteotomy of the distal radius, combined correction of the radius and ulna, as well as isolated correction of the ulna (distal resection, step-cut osteotomy, hemiresection arthroplasty). 83 (86.5%) of the patients were followed up for an average of 7 years postoperatively. The functional results were evaluated according to Lidström. Excellent and good results were found in 58 (69.9%), fair in 20 (24.1%) and bad results in 5 (6.0%). The best results were mostly seen in cases with a short interval between trauma and corrective procedure. Distal ulna resection has not been performed in our department since 1986 because of poor results and concommitant wrist-instability. We recommend combined correction procedures in those patients with painful deformities within a period of no more than six to nine months after trauma. The indication should also take individual aspects such as profession, age, activities, complaints, and radiological findings into account. Signs of osteoarthrosis and wrist disorders due to severe soft tissue problems are contra-indications to any of the aforementioned correction procedures.

Adolescent↗
PubMed1991

[The staging diagnosis of Hodgkin's disease. A comparison of laparotomy and noninvasive methods].

The diagnostic efficiency of modern noninvasive methods more and more puts into question the need for exploratory laparotomy to determine the stage of Hodgkin's disease. In 208 patients (122 men and 86 women; mean age 29 [14-62] years) pre- and postoperative findings as to stage of the abdominal disease were compared. All patients had first been examined by ultrasound and computed tomography, followed by laparotomy with splenectomy. Findings of lymphography were available for 171 patients. Gross and microscopic examination of the tissues obtained by splenectomy and lymphadenectomy, as well as liver biopsy provided different stages from the preoperative ones, which in 46 had been false-negative, and in 16 false-positive. Spleen weight and involvement of the spleen with Hodgkin infiltration correlated only weakly with one another. In 38 of 41 patients with parapancreatic and splenohilar lymphnode involvement the spleen was also affected. These results indicate that regarding the stage of Hodgkin's disease, noninvasive methods so far do not achieve the validity of pathological examination obtained at exploratory laparotomy with splenectomy.

Adolescent↗
PubMed1991

Polymorphic karyotypes in related Acremonium strains.

A restriction fragment length polymorphism (RFLP) analysis was performed on six related Acremonium strains. With respect to the restriction fragment pattern, all strains of A. chrysogenum were indistinguishable from each other but showed distinctive differences from those of A. strictum, A. flavum and Cephalosporium polyvaleurum. Using pulsed-field gel electrophoresis, we obtained different chromosome patterns from most of the Acremonium strains. Remarkably, the pattern varies in three related A. chrysogenum strains which also differ in their rate of cephalosporin C biosynthesis. The electrophoretic karyotyping was confirmed by the location of rDNA genes on separate chromosomes. Our data indicate that chromosome translocations in industrial strains may be responsible for increased beta-lactam synthesis.

Acremonium↗
PubMed1991

Impairment of specific host defense mechanisms in patients with chronic post-traumatic osteomyelitis.

We studied both in vivo and in vitro specific host defense mechanisms in patients suffering from chronic post-traumatic osteomyelitis (n = 26). The cell-mediated immunity in vivo was impaired as indicated by the reduced reactivity in the delayed type hypersensitivity skin test. The concanavalin A or phytohemagglutinin-induced T-cell proliferation in vitro was markedly decreased in comparison to healthy donors. In contrast, B-cell proliferation stimulated by Staphylococcus aureus Cowan I was not altered. While the absolute lymphocyte counts and the percentage of T, B, and O cells were within the normal range, nine out of the 26 patients showed a significantly diminished ratio of CD4+ and CD8+ T cells. Humoral immunity in the patients was less affected as assessed by the unchanged serum levels of immunoglobulins (Ig). However, the T-cell dependent polyclonal Ig synthesis after in vitro stimulation with pokeweed mitogen was suppressed. Our results provide evidence that cell-mediated immune functions are predominantly impaired in patients with post-traumatic osteomyelitis which may contribute to the persistence of the localized bone infection.

Adolescent↗
PubMed1991

[Post-traumatic correction osteotomy of the distal forearm. Which factors modify the results?].

Post-traumatic deformities are a typical complication of fractures of the distal radius, occurring in about 20% of cases. They are associated with ulno-carpal pain and malfunction of the wrist. Different indications for surgery are given and various operative techniques are recommended. Between 1972 and 1987 a total of 108 patients with post-traumatic disorders following fractures of the distal radius underwent surgical treatment by one of three different procedures: isolated correction of the distal radius, combined correction of the radius und ulna, isolated correction of the ulna (distal resection, shortening osteotomy, hemiresection arthroplasty). 92 (85.2%) followed-up for an average of 9 years postoperatively was possible in 92 (85.2%) of the patients. The functional results were evaluated according to Lidström's system. Excellent and good results were found in 64 (69.6%), fair results in 22 (23.9%), and poor results in 6 (6.5%) of the patients studied. The best results were seen mainly in cases with a short time lapse between trauma and corrective surgery. Distal resection of the ulna has not been performed since 1986 because of poor results and wrist instability. Following isolated correction of radius or ulna, in some patients axial malalignment of the distal radius by about 10 degrees and/or length differences of 2-3 mm with persisting pain or malfunction were seen. In summary, we recommend the combined correction procedure in patients with painful deformities, not more than 6-9 months after the injury. The range of indications should be determined by individual aspects, such as profession, age, activity, discomfort and radiological findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthroplasty↗
PubMed1990

[Sonographic diagnosis in blunt thoracic trauma].

Chest sonography after blunt thoracic trauma allows the immediate institution of emergency treatment before X-ray examination. Especially in cases of hemothorax or/and hemopericardium, ultrasound is more specific and sensitive than conventional X-ray. A definite diagnosis of pneumothorax is possible when the typical sonographic findings are present: there is a strong line of reflexes along the chest wall, with complete extinction. Unilateral intensification of air-stipulated repeating echoes may be a sign of mantle pneumothorax. Ruptures of the diaphragm are usually recognizable on radiographic examination only when there is massive intrathoracic splanchnectopia. They are better recognized by ultrasound examination, so that iatrogenic complications caused by thoracocentesis can be avoided. Continued ultrasound check-ups are necessary to reveal any secondary appearance of pleural fluid and to monitor the effect of pleural drains. Ultrasound is also useful for guidance when pleural aspirations are performed. In 64 patients sonography showed hemothorax in 39 cases (radiographic: 13 certain, 9 uncertain), hemopericardium in 1 case, and rupture of the diaphragm in 1 case (radiography: no pathologic findings in either of the last 2). In 2 cases rupture of the diaphragm seemed possible on ultrasound but was excluded by later (ultrasound) controls, and in 2 cases with ultrasound findings suggestive of pneumothorax subsequent X-ray examination confirmed the diagnosis of mantle pneumothorax. At follow-up, 29 pathologic findings according to radiographic examination were recognized on ultrasonography as liquid or organized pleural effusions or pulmonary infiltrates. False-negative or false-positive findings (apart from two supposed diaphragmatic injuries) were not recorded with ultrasound.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗