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Biomedical subjects

K Borg

Publications and source records attributed to K Borg.

At least 55 records · Page 3Linked to original sources
PubMed1996

C-peptide improves autonomic nerve function in IDDM patients.

In order to determine the possible influence of C-peptide on nerve function, 12 insulin-dependent diabetic (IDDM) patients with symptoms of diabetic polyneuropathy were studied twice under euglycaemic conditions. Tests of autonomic nerve function (respiratory heart rate variability, acceleration and brake index during tilting), quantitative sensory threshold determinations, nerve conduction studies and clinical neurological examination were carried out before and during a 3-h i.v. infusion of either C-peptide (6 pmol.kg-1.min-1) or physiological saline solution in a double-blind study. Plasma C-peptide concentrations increased from 0.11 +/- 0.02 to 1.73 +/- 0.04 nmol/l during C-peptide infusion. Clinical neurological examination quantitative sensory threshold evaluations and nerve conduction measurements failed to detect significant changes between C-peptide and saline study periods. Respiratory heart rate variability increased significantly from 13 +/- 1 to 20 +/- 2% during C-peptide infusion (p < 0.001), reaching normal values in five of the subjects; control studies with saline infusion did not alter the heart rate variability (basal, 14 +/- 2; saline, 15 +/- 2%). A reduced brake index value was found in seven patients and increased significantly during the C-peptide infusion period (4.6 +/- 1.0 to 10.3 +/- 2.2%, p < 0.05) but not during saline infusion (5.9 +/- 2 to 4.1 +/- 1.1%, NS). It is concluded that short-term (3-h) infusion of C-peptide in physiological amounts may improve autonomic nerve function in patients with IDDM.

Adult↗
PubMed1996

Magnetic resonance imaging of lower extremity muscles and isokinetic strength in foot dorsiflexors in patients with prior polio.

The thigh and lower leg of six patients with prior polio were examined using magnetic resonance imaging (MRI), and the strength of their weak foot dorsiflexors was measured isokinetically. Spinecho images of the lower extremities were visually evaluated on a semi-quantitative four-point scale, and T1 and T2 relaxation times of the lower leg anterior compartment were analysed. There were prominent MRI signs of randomly distributed muscle degeneration. The high signal intensity changes in the affected muscles on T1-weighted images and T1 and T2 values indicated replacement of muscle fibres with fat and the accumulation of tissue water, respectively. MRI findings were compared with isokinetic strength in foot dorsiflexor muscles. Foot dorsiflexor peak torque values at 30 deg/s ranged from 6 to 29 Nm. There was no significant correlation between MRI visual scoring, T1 and T2 relaxation times and peak torque values at 30 deg/s. However, the most severe MRI changes with visual scoring and T2 relaxation times were observed in the patients with the most pronounced muscle weakness.

Aged↗
PubMed1995

Bridges supported by free-standing implants versus bridges supported by tooth and implant. A five-year prospective study.

The clinical question at issue, whether it is possible to combine implants and natural teeth via fixed bridges, is of current interest. The treatment of the subjects of this prospective study was performed between June 1984 and December 1986. This article presents the 5-year results of the study. The consecutive patient material comprised 23 patients with Applegate Kennedy Class I residual dentition in the mandible and a complete maxillary denture. All 23 patients were provided with implants ad modum Brånemark in each mandibular quadrant. One side was randomized to rehabilitation with fixed bridge between the distal tooth of the residual dentition and an implant; the other side received a free-standang bridge on 2 implants. The fixture survival rate was 88%. No difference was found between the two sides. Bridge stability was 89% for the implant bridges and 91% for the combination bridges. The change in marginal bone level at the implants was small during the 5-year follow up period (on average 0.1-0.3 mm) and with no difference between the two sides. In conclusion, it was not possible to demonstrate any higher risk of implant or prosthetic failure for tooth-implant fixed bridges compared with implant-supported bridges.

Alveolar Bone Loss↗
PubMed1995

Social phobia: the clinical efficacy and tolerability of the monoamine oxidase -A and serotonin uptake inhibitor brofaromine. A double-blind placebo-controlled study.

Seventy-seven patients with a primary diagnosis of social phobia (DSM-III-R) were randomized to treatment with the reversible and selective monoamine oxidase type A inhibitor brofaromine (n = 37) or placebo (n = 40) for 12 weeks in a double-blind trial. A fixed dose of 150 mg/day or a matching placebo was given after a 2-week dose titration phase. Patients with additional diagnoses of simple phobia, generalized anxiety disorder, dysthymia or major depressive disorder currently in remission were accepted. Patients with other Axis I mental disorders were excluded. In the brofaromine group, 78% of the patients scored much or very much improved on the Clinical Global Impression scale compared with 23% in the placebo group. The anxiety and avoidance scores on the Liebowitz Social Anxiety Scale (LSAS) were significantly reduced in favor of brofaromine. The clinical effects were not significantly correlated with the plasma concentration of brofaromine. After 12 weeks the brofaromine group scored significantly lower than the placebo group on a core depression part of the Montgomery-Asberg Depression Rating Scale. After 12 weeks of treatment the brofaromine group had significantly higher total scores on the LSAS than an age- and gender-matched group of healthy controls. The brofaromine group improved further during 9-month follow-up treatment period, whereas 60% of the placebo responders who continued long-term treatment relapsed. The most common side effects in the brofaromine group were sleep disturbances, dry mouth and nausea.

Adult↗
PubMed1994

Distribution of muscle degeneration in Welander distal myopathy--a magnetic resonance imaging and muscle biopsy study.

Seven patients with Welander distal myopathy were subjected to magnetic resonance imaging (MRI) of the lower extremity, and muscle biopsies of the tibialis anterior, soleus and vastus lateralis muscles. MRI revealed abnormalities in both the anterior and posterior compartments of the lower leg in three of the patients, and in only the posterior compartment in the rest of the patients. No MRI abnormalities were found in either the proximal muscles of the leg or in the peroneal or posterior tibial muscle groups. Affected muscles had T1- and T2-values indicating a replacement of muscle fibres with fat tissue. Muscle biopsies showed pathological changes varying from slight to severe in tibialis anterior and soleus muscles in all patients. No muscle fibre abnormalities were seen in the vastus lateralis muscle in any of the patients. In accordance with earlier reports from patients with Welander distal myopathy, there was muscle degeneration of tibialis anterior muscles corresponding to the weakness of dorsal extension of the feet, but also degeneration in the muscles of the posterior compartment. The patients did not, however, show any clinical signs of weakness related to posterior muscle groups. There is no evidence of involvement of proximal muscles of the leg clinically, with MRI or in muscle biopsies.

Adult↗
PubMed1993

Muscle fibre degeneration in distal myopathy (Welander)--ultrastructure related to immunohistochemical observations on cytoskeletal proteins and Leu-19 antigen.

In seven patients with long-standing and six patients with early symptoms of Welander distal myopathy (WDM), monoclonal antibodies directed against such cytoskeletal proteins as dystrophin, spectrin and desmin and against Leu-19, a myoblast and satellite cell related antigen, were applied to muscle biopsies from the anterior tibial and soleus muscles. In addition, ultrastructural studies were carried out on biopsies from the soleus muscle. In muscle fibres from patients with early symptoms there was normal immunostaining for dystrophin, spectrin, desmin and Leu-19. In the patients with long-standing symptoms, there was also a normal expression of dystrophin, and a normal staining for spectrin and desmin was found in normal sized muscle fibres. Occasionally normal sized muscle fibres showed staining for Leu-19. Increased staining for spectrin and desmin and a strong Leu-19 staining was seen in normal sized muscle fibres with rimmed vacuoles and in atrophic fibres. Increased staining for spectrin, desmin and Leu-19 has been described in denervated muscle fibres and, thus, the present findings may support earlier findings of a neurogenic component in Welander distal myopathy. In the soleus muscle, ultrastructural muscle fibre abnormalities conformed to those in the anterior tibial muscle. Many rimmed vacuoles were observed which corresponded, at the ultrastructural level, to autophagic vacuoles. Intranuclear and cytoplasmic filamentous inclusions of the same shape and diameter as in inclusion body myositis were observed.

Adult↗
PubMed1993

Paramyotonia congenita (Eulenburg): clinical, neurophysiological and muscle biopsy observations in a Swedish family.

A Swedish family with Paramyotonia congenita (Eulenburg) (PMC) is presented. Clinical neurological examination, neurophysiological examination (n = 5) and muscle biopsy (n = 4) were performed. Different clinical features were found in various combinations in the individual family members. The clinical symptoms were: (1) cold-induced myotonia, (2) attacks of weakness, (3) persistent weakness and (4) no symptoms but other signs of muscle affection. In the patients with myotonia, the neurophysiological examination showed spontaneous myotonic discharges which were frequent at room temperature but disappeared after cooling. Furthermore, the amplitude of M. abductor digiti minimi compound action potential, during supramaximal ulnar nerve stimulation, decreased significantly after cooling. In the patients with persistent weakness there were no spontaneous myotonic discharges, but myopathic abnormalities were found in proximal muscle. In the patients with myotonia as well as in the patients with manifest muscle weakness, muscle biopsy showed a variation of muscle fibre diameters, centrally located nuclei, occasional atrophic fibers and an atrophy of type IIB muscle fibres. These findings are unspecific but have been described in PMC patients in earlier studies. An ancestor to the family, who had myotonia, lived in the same town and at the same time as Albert Eulenburg, which may suggest that this family is a part of the originally described family (1).

Action Potentials↗
PubMed1993

Prior poliomyelitis: an immunohistochemical study of cytoskeletal proteins and a marker for muscle fibre regeneration in relation to usage of remaining motor units.

Patients with prior poliomyelitis with paresis and excessive use (n = 8) and low use (n = 6) of residual anterior tibial motor units (MUs) during walking were subjected to muscle biopsy of the anterior tibial muscle (TA). Antibodies directed against cytoskeletal proteins, spectrin and desmin, and against Leu-19, a myoblast and satellite cell related antigen, were applied. In the patients with excessive use of residual MUs there was an almost total predominance of hypertrophic type I fibres. In the hypertrophic fibres, staining for spectrin and desmin was normal while staining for Leu-19 was seen in a few fibres. Scattered atrophic fibres seen in the patients with excessive use showed staining for spectrin, desmin and Leu-19. In the patients with low use of residual MUs there were extensive pathological muscle fibre changes. Increased staining for spectrin, desmin and Leu-19 was found in most of the atrophic fibres. The predominance of type I fibres in the patients with excessive use of residual MUs is suggested to be due to muscle fibre transformation. The normal staining pattern for spectrin and desmin in the hypertrophic fibres indicates a normal cytoskeletal structure which might suggest that the adaptive muscle fibre changes are adequate to meet the increased demand. The increased staining for spectrin, desmin and Leu-19 in the atrophic fibres might indicate an ongoing denervation process which earlier has been suggested as an important factor for the development of postpolio progressive muscular atrophy.

Adult↗
PubMed1993

Isokinetic strength, macro EMG and muscle biopsy of paretic foot dorsiflexors in chronic neurogenic paresis.

Ten ambulatory patients with chronic dorsiflexor paresis due to prior poliomyelitis or lumbar root (LV) lesion and without recent decline of the foot dorsiflexor strength were examined with isokinetic strength measurement, macro EMG and muscle biopsy. Isokinetic strength measurement showed peak torques at 30 degrees/s angular velocity ranging 6-44 Nm and at 240 degrees/s 1-10 Nm. Mean of individual median macro EMG motor unit potential amplitudes was 2020 microV (SD 1040) which was 5-10 times higher than expected values in healthy subjects. Muscle biopsies showed a mean type 1 fibre proportion of 91% (SD 14) and a mean type 1 fibre area of 8561 microns 2 (SD 2773) which was about 2 times larger than those observed in healthy subjects. Peak torque and both motor unit potential amplitude and area were inversely correlated at 30 (p < 0.01 and p < 0.025), 60 (p < 0.025 and p < 0.025) and 120 (p < 0.05 and p < 0.05) degrees/s angular velocity, as were peak torque and type 1 muscle fibre proportion at 30 (p < 0.05) and 60 (p < 0.05) degrees/s angular velocity. Peak torque or macro EMG parameters were not correlated to muscle fibre area. The data suggest that the remaining muscle strength was directly correlated to the degree of collateral sprouting and that about half of it could be attributed to compensatory muscle fibre hypertrophy.

Aged↗
PubMed1992

Implants in partially edentulous patients. A longitudinal study of bridges supported by both implants and natural teeth.

The aim of the study was to compare the outcome of bridges supported by implants with bridges supported by a combination of implants and natural teeth abutments. The study comprised 23 patients with Applegate Kennedy Class I dentition in the mandible and a full upper denture. Implants ad modum Brånemark were inserted in the posterior areas of both mandibular quadrants. On one side, a bridge supported by 2 implants was constructed (Type I) and on the other side, a bridge supported by 1 tooth (mostly the canine or first premolar) and 1 implant was made (Type II). A total of 46 bridges were made and during the 3-year follow-up period, 4 Type I and 2 Type II bridges were lost. 8 out of 69 implants were lost during the 3-year follow-up, resulting in an implant survival rate of 88.4%. Marginal bone loss, one of several parameters, was evaluated on standardized intraoral radiographs. This was performed during the 1st and 2nd year of function and the total mean bone loss from loading was 0.46 mm and 0.56 mm, respectively. The bone loss during the 2nd year of function was significantly less, adjacent to implants supporting Type II bridges, than adjacent to implants supporting Type I bridges. Summarily, no disadvantages of combining of teeth and implants in the same bridge were found in this study. On the contrary, the slightly lower marginal bone loss adjacent to implants in Type II bridges may indicate that the bone reactions could be more favorable when bridges are connected to both implants and teeth.

Alveolar Bone Loss↗
PubMed1992

Torque-velocity relation and muscle fibre characteristics of foot dorsiflexors after long-term overuse of residual muscle fibres due to prior polio or L5 root lesion.

Isokinetic foot dorsiflexion strength and muscle biopsy data from eight patients with overuse of tibialis anterior muscle (TA) fibres due to weakness after prior polio or L5 root lesion were compared to data from age and sex matched, healthy subjects. Concentric peak torque at an angular velocity of 30 degrees/s was 6-24 Nm in the patients and 15-34 Nm in the controls (p < 0.01). Muscle biopsies from TA showed a significantly higher proportion of type 1 fibres in the patients as compared to the controls (p < 0.005). The type 1 fibres in the patients had a significantly larger cross-sectional area than in the controls (p < 0.005). The type 1 fibre proportion and relative area were inversely correlated to the relative concentric torque produced at 180 degrees/s (p < 0.05) and 240 degrees/s (p < 0.05) compared to that produced at 30 degrees/s in the controls but not in the patients. However, the relative concentric torque produced at 180 degrees/s and 240 degrees/s compared to that produced at 30 degrees/s was not significantly different in the patients and the controls. This indicates that the contractile properties of the overused muscle fibres do not change in parallel with the histochemical fibre type.

Aged↗
PubMed1991

Intranuclear and cytoplasmic filamentous inclusions in distal myopathy (Welander).

Ultrastructural examination of anterior tibial muscle from four patients with late-onset autosomal dominant distal myopathy of Welander-type revealed intrasarcoplasmic filamentous inclusions in association with rimmed vacuoles. In one of the patients, identical intranuclear filamentous inclusions were also found. These filamentous inclusions are similar to those described in inclusion body myositis (IBM). They have also been observed in hereditary neuromuscular disorders including autosomal recessive distal myopathy. Thus, the filamentous inclusions occur in different neuromuscular conditions with different etiologies. These findings further raise the question of the specificity of the filamentous inclusions in IBM.

Adult↗