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Biomedical subjects

C Rolf

Publications and source records attributed to C Rolf.

At least 55 records · Page 3Linked to original sources
PubMed1998

Local bone deformation at two predominant sites for stress fractures of the tibia: an in vivo study.

Local bone deformation was registered at two predominant injury sites for tibial stress fractures in a healthy female volunteer. Two instrumented strain gauge staples were inserted under local anesthesia to the anterior middiaphysis (AM) and to the posteromedial part of the distal tibia (PD). Calibration and reliability of the instrumented staple system have previously been demonstrated in vitro. Concomitant ground reaction forces were registered with a Kistler force plate. Studying peak values, it was shown that during a voluntary 30-cm forward jump, PD deformation was greater during forefoot landing (2700-4200 microstrain) than during a heel strike landing (1200-1900 microstrain) and also compared with the concomitant AM deformation under both above testing conditions (1300-1900 microstrain). The stance phase during walking resulted in PD deformation of 950 microstrain, whereas the concomitant AM deformation was 334 microstrain. The greatest AM deformation (mean, 2128 microstrain) was registered during ground contact after a voluntary vertical drop from a height of 45 cm, concomitant with a PD deformation of 436 microstrain. These data are the first to show different local deformations at various sites of the tibia in vivo. The PD deformation was larger than previously noted from other parts of the tibia, whereas the middiaphysis data are consistent with other reports. The results may support the clinical assumption of different etiologies for stress fractures at these predominant sites.

Adult↗
PubMed1998

Testosterone levels in men with chronic obstructive pulmonary disease with or without glucocorticoid therapy.

Under the clinical impression that patients with chronic obstructive pulmonary disease (COPD) may demonstrate signs compatible with hypogonadism, we investigated whether oral glucocorticoid therapy is associated with testosterone deficiency. Thirty six men with COPD of whom 16 were receiving oral glucocorticoid medication (mean+/-SEM dose 9.4+/-1.1 mg prednisolone) were investigated in a cross-sectional cohort study. Patients with or without oral glucocorticoid therapy were not different in terms of age, smoking history and additional therapy. Vital capacity, forced expiratory volume in one second, airway resistance, intrathoracic gas volume and blood gases at rest were not different between the groups. However, patients receiving glucocorticoids had a shorter 6 min walking distance (mean+/-SEM 205+/-27 versus 288+/-26 m; p=0.02) compared to patients without oral steroid therapy. Serum levels of testosterone (mean+/-SEM 13.7+/-0.9) were below normal (<12 nM) in 15 of 36 patients. Serum testosterone did not correlate with any other evaluated parameter. Serum levels of free testosterone (free T) (mean+/-SEM 172.3+/-7.8 pM) were decreased in 25 of the 36 patients, including all patients receiving glucocorticoid treatment. In the 16 patients taking glucocorticoids free T was correlated (p=0.016) with the current glucocorticoid dosage (r=-0.504; p=0.007) and the body mass index (r=0.241; p=0.037). All other parameters examined revealed no significant correlations in multiple regression analysis. Glucocorticoid treatment appears to aggravate hypogonadism and a therapeutic study using testosterone in patients with chronic obstructive pulmonary disease receiving glucocorticoid medication appears warranted.

Administration, Oral↗
PubMed1997

Screening for deletions of the Y chromosome involving the DAZ (Deleted in AZoospermia) gene in azoospermia and severe oligozoospermia.

OBJECTIVE: To evaluate the occurrence and prevalence of microdeletions of the Y chromosome involving the DAZ (Deleted in AZoospermia) gene in patients with azoospermia or severe oligozoospermia. DESIGN: Controlled clinical study. SETTING: University infertility clinic. PATIENT(S): Infertile men (n = 168) with nonobstructive, idiopathic azoospermia or severe oligozoospermia and normal LH. The control group consisted of proven fathers (n = 86). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Semen analysis; polymerase chain reaction amplification of the loci sY84, sY143, sY254, and sY255; serum FSH, LH, and T; testicular volume. RESULT(S): Deletions involving the sY254 and sY255 DAZ loci were found in three azoospermic patients and two men with sperm concentration < 1 x 10(6)/mL. Serum FSH was elevated in four patients and was normal in one. All five patients had decreased testicular volumes compared with controls. No deletions involving the sY84 and sY143 loci were found. The four loci were amplified normally in the control group. CONCLUSION(S): The estimated frequency of deletions involving the DAZ locus is 3% in azoospermic-severely oligozoospermic men consulting an infertility clinic. Polymerase chain reaction amplification of the DAZ locus is useful for the diagnosis of microdeletions of the Y chromosome. Deletions involving more proximal regions of the Y chromosome seem to be rare.

Adult↗
PubMed1997

Differential effect of GM-CSF pretreatment on intracellular Ara-C metabolism in normal bone marrow mononuclear cells vs acute myeloid leukemia (AML) blasts.

The effect of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the intracellular metabolism of cytosine arabinoside (Ara-C) was comparatively analyzed in normal bone marrow mononuclear cells (NBMMC) from eight healthy volunteers and in leukemic blasts from 50 patients with acute myeloid leukemia (AML). Pretreatment with GM-CSF (100 U/ml) for 48 h resulted in a significant enhancement of DNA synthesis in both cell types: 21 of 35 AML specimens were found to be responsive to GM-CSF as defined by an increase of 3H-TdR incorporation into the DNA > 1.5-fold while NBMMC from normal donors were responsive in all cases. In GM-CSF responsive AML blasts, overall DNA polymerase and DNA polymerase alpha activity increased from a median of 84.4 to 96.1 and from 3.45 to 5.2 pmol/min x mg as compared to a median of 96.7 to 189.9 and 1.2 to 2.2 pmol/min x mg in NBMMC (P < 0.05). Median Ara-C-mediated inhibition of DNA synthesis was significantly more effective in AML blasts as compared to NBMMC (76.5 vs 55.0% at 0.05 microM and 99.0 vs 96.0% at 5.0 microM Ara-C, P < 0.01) but was not influenced by GM-CSF pretreatment. Similarly, intracellular Ara-CTP levels were higher in AML blasts as compared to NBMMC (median of 46.9 vs 18.7 at 1 microM, 167.8 vs 48.0 at 10 microM and 337.5 vs 59.5 ng/10(7) cells at 100 microM extracellular Ara-C, P < 0.01) but showed no enhancement in the presence of GM-CSF. Median deoxycytidine (DCK) and thymidine kinase (TK) activity were only slightly increased in AML blasts after GM-CSF priming. In contrast, NBMMC revealed a significant increase in TK activity after GM-CSF pretreatment (from a median of 1.9 to 3.6 pmol/min x mg, P = 0.039). At low; intermediate and high extracellular Ara-C concentrations GM-CSF pretreatment resulted in a significant enhancement of the 3H-Ara-C incorporation into the DNA in both GM-CSF responsive AML blasts and NBMMC (median of 1.3 to 2.1- and 1.4 to 1.6-fold, P < 0.05). GM-CSF non-responsive AML blasts showed no change in 3H-Ara-C incorporation into the DNA in response to GM-CSF at low Ara-C concentrations but significant increases at intermediate and high extracellular Ara-C concentrations (median increases of 1.63-fold at 1.06 microM with P = 0.01 and 1.37-fold at 10 microM extracellular Ara-C with P = 0.0+005). NBMMC revealed significantly lower GM-CSF-induced increases of the 3H-Ara-C incorporation into the DNA as compared to the effect of GM-CSF priming on DNA synthesis (median increases of 1.4 to 1.7-fold vs 2.6-fold, P < 0.05). These data reveal a different effect of GM-CSF priming on the metabolism of Ara-C in normal vs leukemic cells which may cause a preferential increase in the antileukemic cytotoxicity of Ara-C in the presence of GM-CSF.

Adult↗
PubMed1997

Aerobic and anaerobic work capacities and leg muscle characteristics in elite orienteers.

Aerobic and anaerobic work capacities, leg muscle structure and metabolic characteristics of m. vastus lateralis (NT), m. rectus femoris (RG) and mm. gastrocnemii (NT and RG) were analysed in five male and seven female elite orienteers from the Swedish National team (NT) and a reference group (RG) of eight male and 10 female upcoming orienteers, all in optimal shape at the end of a competitive season. Maximal oxygen uptake was 78.4 ml/kg/min for NT men (range 75-81) and 67.8 ml/kg/min for NT women (range 62-71), for both groups significantly higher (P < 0.001) than for RG. Maximal serum lactate was 13.3 mmol/l for NT men (range 10-17) and 11.7 mmol/l for NT women (range 8.4-14), which did not differ from RG. No significant correlation was found between maximal oxygen uptake and maximal serum lactate. For NT females only maximal oxygen uptake was significantly related to running economy (P < 0.01). Muscle biopsies showed a high content of type I fibres in m. vastus lateralis as well as in m. gastrocnemius mediale. M. vastus lateralis (NT) had a higher proportion of type I fibres, capillaries per fibre as well as CS, HAD and LDH 1-2 enzymes compared with m. rectus femoris (RG) (P < 0.001-< 0.001), the latter muscle showing a more anaerobic profile. NT males and females had a higher metabolic potential in m. gastrocnemius mediale than RG (P < 0.001). Our results reflect an obligate high and narrow range of aerobic and anaerobic work capacities for successful performance in international elite orienteering. It remains to be shown how these laboratory data are related to individual performance in authentic orienteering competitions.

Adult↗
PubMed1997

An experimental in vivo method for analysis of local deformation on tibia, with simultaneous measures of ground reaction forces, lower extremity muscle activity and joint motion.

This paper presents the pilot procedures of a new in vivo experimental method for measures of local bone deformation on tibia. The tibia transducer consists of a strain gauge mounted on a surgical staple, and was designed to measure local bone deformation. Pilot measurements were undertaken during two standardized conditions of forefoot and heel landing in seven healthy volunteers. Implantation of two tibia force transducers on tibia were performed under local anaesthesia. The local peak tibia deformation occurred at 20-42 ms (median) after ground contact, and was up to eight times higher during stance phase loading compared with standing still on one leg. Ground reaction forces, muscle activation patterns and kinematics were registered simultaneously, and were used to validate that the observed local deformation on tibia occurred under controlled and clinically relevant conditions. The new method may be used for investigating local deformation within various bone structures of the lower extremity. There are further methodological issues to address before major clinical interpretations may be concluded. In order to verify that the strain gauge transducer system was valid, a controlled displacement of the staple shanks was performed with a micrometer, and showed a linear relationship between applied deformation and strain gauge response (r = 0.97-0.99). In addition, a linear relationship was found between externally applied static forces and strain gauge response in a four-point bending cadaver system (r = 0.96-0.98).

Adult↗
PubMed1997

Ultrasonography-guided percutaneous core biopsy in Achilles tendon disorder.

Ultrasound-guided percutaneous core biopsy technique was studied in 15 consecutive patients with chronic Achilles tendon disorder defined as persisting local pain during daily activities, localized pain and swelling on palpation 2-5 cm proximal to the calcaneal insertion. Ultrasound verified widening of the tendon and low echogenous areas at the site of pain. Percutaneous biopsies were taken from both the low echogenous areas and the normoechogenic tendon tissue. Of 104 core biopsies 99 were representative. Open biopsies were taken from the macroscopically injured and normal tendon for comparison. Core and open biopsies of the low echogenous and macroscopically injured tendon showed similar histopathology. In 10 patients the core biopsy was performed under local anesthesia with limited subjective symptoms. Five of these patients were operated 18-41 days later. No adverse effect was found referring to the biopsy taken a few weeks prior to surgery. No complications occurred. We conclude that the percutaneous core biopsy, guided by ultrasound and performed under local anesthesia, can be used under clinical and experimental in vivo studies for improving knowledge on pathoanatomy and healing processes of the Achilles tendon.

Achilles Tendon↗
PubMed1997

The anterior stress fracture of the tibia: an atrophic pseudoarthosis?

Histopathological examination of biopsies from the fracture site in two cases of anterior stress fractures of the tibia demonstrated no bone remodelling activity, absence of inflammatory cells, extensive fibrotic infiltration and local avascular bone necrosis. The biopsies were taken peroperatively from two elite soccer players who earlier had to stop training due to severe exertional pain. When non-operative treatment failed to heal the fractures within 1 year and 6 months, respectively, surgery was performed in order to stabilize the fractures. Both subjects were relieved from exertional pain within 6 months of surgery. Consecutive radiographs showed the pattern of direct healing and 8 months postoperatively confirmed complete healing without callus formation. Both elite soccer players returned to pre-injury activity level. We suggest that the excessive fibrotic tissue ingrowth and hypovascularity under repetitive stress causes the delayed healing and histopathological signs similar to an atrophic pseudoarthosis. Treatment should consequently consider the pseudoarthrotic character of the anterior stress fracture of the tibia.

Adult↗
PubMed1997

Pathology of the Achilles tendon in association with ciprofloxacin treatment.

Achilles tendon pain or rupture after fluoroquionolone treatment has been described as an uncommon adverse effect. We report two patients with ciprofloxacin-associated Achilles tendon disease, one with histopathological examination. Microscopic evaluation showed irregular collagen fiber arrangement, hypercellularity, and increased interfibrillar glycosaminoglycans. These pathological features are also seen in tendon overuse injuries in athletes.

Achilles Tendon↗
PubMed1997

Etiology, histopathology, and outcome of surgery in achillodynia.

Fifty-eight patients suffering from achillodynia for a median of 12 months (range, 4-240 months) were analyzed using history, clinical findings, ultrasound findings, histopathology, and surgical outcome. Surgical criteria were daily pain or inability to perform sports activity and failure of nonoperative treatment. There were 34 men and 24 women, 31% (18 of 58 patients) of whom had no direct association with sports or vigorous physical activity. Ultrasonography was performed in all cases and showed low echogenous areas (N = 48), increased tendon diameter (N = 40), and/or peritendinous fluid (N = 11). Histopathological evaluation of tendon biopsies, obtained from regions showing pathology at surgery (N = 35), revealed altered fiber structure and arrangement, focal variations in cellularity, extracellular glycosaminoglycans, neovascularization, and/or hyalinization. In no case was inflammatory cell infiltration observed. At a median clinical follow-up of 25 months after surgery, symptoms were decreased in 86% of patients, and 76% had reached a higher activity level compared with the level before surgery. Complications occurred in 13% of operations. In conclusion, achillodynia is not always associated with excessive physical activity. Macroscopic pathologic tendons showed marked histopathologic changes, correlating well with ultrasound findings. Surgical treatment was beneficial in most cases, despite a relatively high complication rate. The etiology and reason for the lack of healing response to rest and nonoperative treatment are unclear.

Achilles Tendon↗
PubMed1997

Tendon pathology in long-standing achillodynia. Biopsy findings in 40 patients.

We evaluated biopsy specimens from the Achilles tendon in 40 patients with long-standing achillodynia and an ultrasonographic widened tendon with hypoechogenic areas. We used a standardized protocol to assess the general tendon pathology score of paraffin-embedded specimens stained with HE. Stereologic measurement of the volume density of glycosaminoglycan (GAG)-rich areas, stained with the Alcian blue (pH 2.5)/periodic acid Schiff method (AB/PAS) was performed. 14 specimens obtained at autopsy served as reference material. Abnormal fiber structure and arrangement, focal variations in cellularity, rounded nuclei, decreased collagen stainability and increased non-collagenous extracellular matrix were seen in all biopsy specimens. Slight histopathological changes were noted in half of the controls. Increased vascularity was present in two thirds of the patient specimens and in one third of the controls, and signs of perivascular hemorrhage, as evidenced by hemosiderin deposition in 6/40 of the patients, but in none of the controls. The volume density of GAG-rich areas was higher in the patients 0.47 (0-0.86) than in the controls 0 (0-0.07). Changes in the fiber structure and arrangement, as well as increased amounts of interfibrillar GAG, appear to be characteristic morphological features in Achilles tendons with long-standing achillodynia and ultrasonographic widening. These findings may indicate that achillodynia is due to local disturbances in connective tissue metabolism or circulation or to both.

Achilles Tendon↗
PubMed1997

Interaction between infection and exercise with special reference to myocarditis and the increased frequency of sudden deaths among young Swedish orienteers 1979-92.

Infection and fever evoke a cytokine-mediated host response resulting in negative nitrogen balance, muscle protein degradation, which includes the skeletal muscles as well as the heart muscle, and deteriorated muscle function. Physical training has an opposite effect. Moderate physical training also stimulates the immune system, whereas exhaustive and longlasting exercise is followed by a temporary immunodeficiency and an increased susceptibility to respiratory tract infections. Exercise in the acute phase of an infection may promote complications including myocarditis. Exercise in myocarditis is associated with increased organism-associated as well as immune mediated tissue damage. An increased sudden death (SUD) rate among young Swedish male orienteers existed in 1979-92, suggesting (a) common underlying cause(s). Myocarditis was one of the most conspicuous histopathological features. Chlamydia pneumoniae, or a similar organism cross reacting in diagnostic tests, is hypothesized to be a factor causing this increased death rate. High frequency of intense exercise sessions, which was a common practice among the deceased, may have been immunosuppressive, promoting the development of severe myocardial disease.

Adolescent↗
PubMed1997

An open, randomized study of ketoprofen in patients in surgery for Achilles or patellar tendinopathy.

OBJECTIVE: To assess the concentration of ketoprofen, after topical plaster application, in various tissues in relation to plasma levels in 60 patients undergoing surgery for Achilles or patellar tendinopathy; and to analyze whether tissues act as a reservoir of ketoprofen, by evaluating tissue concentrations in relation to plasma concentration at various time points after removal of the plaster. No attempt was made to study the clinical effect of treatment per se. METHODS: In random order to patients applied 30 mg plasters once daily for 5 consecutive days (n = 30), or took a single oral dose 50 mg (n = 30) before surgery. Tissue samples of skin, subcutaneous fat, tendon sheath, and tendon, and plasma were collected intraoperatively at 0, 6 and 14 hours after removal of the 5th plaster, and at 2, 6, and 14 hours after oral intake. Ketoprofen concentration was determined by a validated GC/MS method. The low limit of quantification was 0.5 ng/ml plasma and 0.5 ng/50 mg tissues. RESULTS: High concentrations of ketoprofen were observed in fat, tendon sheath, and tendon after topical applications, whereas plasma levels of ketoprofen were low. CONCLUSION: Ketoprofen attains high concentrations in subcutaneous tissues after multiple topical applications. Subcutaneous tissues appear to act as a reservoir of ketoprofen.

Achilles Tendon↗
PubMed1997

Tarsal tunnel syndrome. Outcome of surgery in longstanding cases.

Cases of longstanding (median, 60 months) tarsal tunnel syndrome were decompressed surgically in 14 female and four male patients. Patients reported intermittent dysesthesia, paresthesia, or anesthesia at the medial plantar aspect of the foot. Symptoms were aggravated by physical activities. Previous trauma was noted in four patients. Tinel's sign was positive in 16 patients. Magnetic resonance imaging was performed in 10 patients but was conclusive in only two. At surgery, the posterior tibial nerve or one of its branches was found to be entrapped in 15 patients. Entrapments were observed isolated or in combination within the fascial septa (n = 5), varicose veins (n = 6), scar tissues (n = 4), tenosynovitis and edema (n = 1), or within the abductor hallucis muscle (n = 1). Two neuromas were excised. In three patients no obvious entrapments were found. Clinical followup was performed a median 18 months after surgery. Relief of symptoms was reported as long as 1 year after surgery. All symptoms were relieved in 11 (61%) patients. Three (17%) patients with previous trauma had relatively severe pain after surgery and were considered to have failed results. Surgical decompression was beneficial in most patients with longstanding tarsal tunnel syndrome.

Activities of Daily Living↗
PubMed1996

Plasma cell granulomas of the brain: pediatric case presentation and review of the literature.

Plasma cell granulomas (inflammatory pseudotumors) are benign inflammatory masses that have been observed in virtually every organ system but are most often described in the lung. Rare cases have been reported in which the brain and spinal cord are affected. We present the case of a 5-year-old girl with personality and behavioral changes, discovered to be harboring an intracerebral plasma cell granuloma. The literature on plasma cell granuloma of the central nervous system is discussed with emphasis on the clinical, radiological, and pathological features of these lesions.

Brain Diseases↗