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Biomedical subjects

J Jakobsen

Publications and source records attributed to J Jakobsen.

At least 55 records · Page 3Linked to original sources
PubMed1997

Muscular atrophy in diabetic neuropathy: a stereological magnetic resonance imaging study.

Diabetic patients with polyneuropathy develop motor dysfunction. To establish whether motor dysfunction is associated with muscular atrophy the ankle dorsal and plantar flexors of the non-dominant leg were evaluated with magnetic resonance imaging in 8 patients with symptomatic neuropathy, in 8 non-neuropathic patients and in 16 individually matched control subjects. In the neuropathic patients the muscle strength of the ankle dorsal and plantar flexors was reduced by 41% as compared to the non-neuropathic patients (p < 0.005). Volume of the ankle dorsal and plantar flexors was estimated with stereological techniques from consecutive cross-sectional images of the lower leg. The neuropathic patients had a 32% reduction in volume as compared with the non-neuropathic patients (p < 0.005). To determine the regional distribution of atrophy cross-sectional magnetic resonance images were performed at predetermined levels of the lower leg in relation to bone landmarks. In the neuropathic patients there was an insignificant increase of 3% of muscle area at the proximal lower leg level, whereas the atrophy was 43% (p < 0.002) at the mid lower leg level and 65% (p < 0.002) distally. Analysis of individual muscles confirmed that the atrophy predominated distally. We conclude that muscular atrophy underlies motor weakness at the ankle in diabetic patients with polyneuropathy and that the atrophy is most pronounced in distal muscles of the lower leg indicating that a length dependent neuropathic process explains the motor dysfunction.

Adult↗
PubMed1997

IgM anti-GM1 antibodies in the Guillain-Barré syndrome: a serological predictor of the clinical course.

It has been suggested that antibodies against GM1 are involved in the pathogenesis of the Guillain-Barré syndrome (GBS). Recently, we have developed a standardized ELISA assay for anti-GM1 antibodies of IgM type well-suited for longitudinal patient studies. The relationship between serum antibodies against GM1 and Campylobacter jejuni was investigated in patients with GBS and in patients with C. jejuni infection. Patients with a short-lasting anti-GM1 elevation had a fast recovery, whereas patients with slow recovery had a long-lasting anti-GM1 elevation. A linear relationship was found between significant clinical recovery and the time until the anti-GM1 peak was halved (R = 0.9, p < 0.01). The absolute level of anti-GM1 did not predict the length of the recovery nor was the level of anti-GM1 related to the clinical disability at its nadir. Our data indicate that monitoring of the IgM anti-GM1 level can predict clinical recovery in GBS patients.

Adolescent↗
PubMed1997

Para-aminobenzoic acid used as a marker for completeness of 24 hour urine: assessment of control limits for a specific HPLC method.

OBJECTIVE AND DESIGN: The study comprised three protocols. Protocol 1 compared a HPLC method with the commonly employed colorimetric diazocoupling method. Protocol 2 examined, if the last dosage of p-aminobenzoic acid (PABA) could be advanced in the old to allow for a delayed age-dependent urinary excretion of PABA. Protocol 3 established limits for recovery of PABA in 24 h urine applying the HPLC method. SUBJECTS AND SETTING: A total of 151 healthy volunteers participated in the study of which 140 were accepted. In protocol 1: 37 subjects aged 20-78 y were included. All subjects took PABA as recommended (80 mg orally at 08.00, 12.00 and 18.00 h). Protocol 2: compared urinary PABA excretion in two groups of 80 y old subjects who had their last PABA dosage administered at 15.00 h (n = 16) and at 18.00 h (n = 31), respectively. Protocol 3: comprised 56 subjects aged 20-80 y. In the younger age group (20-59 y; n = 34) PABA was taken as recommended, whereas in the older age group (60-80 y; n = 22) the last PABA dosage was advanced three hours. RESULTS: Protocol 1: HPLC gave significantly lower PABA recovery results compared to colorimetry, the difference between methods being 23.9 +/- 8.5 mg/24 h (P < 0.001). Protocol 2: higher PABA recoveries were demonstrated with the advanced dosage schedule compared to the recommended schedule (208 +/- 14 mg/24 h vs 181 +/- 22 mg/24 h; P < 0.001). Protocol 3: PABA recovery with HPLC was 211 +/- 12 mg/24 h, and the lower limit comprising 95% of subjects was 187 mg/24 h. Similar PABA recoveries were demonstrated in the younger subjects and the older subjects (211 +/- 11 mg/24 h vs 211 +/- 13 mg/24 h; NS). CONCLUSION: An advanced dosage schedule for PABA in the aged is recommended. Because of lower recoveries with HPLC, the low limit for recovered PABA in a complete 24 h urine differs from the limit based on colorimetry. This study found a limit of 187 mg/24 h corresponding to the lower 95% confidence limit for a single subject.

4-Aminobenzoic Acid↗
PubMed1997

Diabetes mellitus.

Epidemiological studies have documented a high prevalence of diabetic neuropathy. The risk of lower leg amputation is increased three to four times in patients with clinical signs of neuropathy and ankle weakness is more common than hitherto recognized. Increased nerve hydration and increased expression of low affinity p75 receptor for neurotrophins suggest new therapeutic potentials for the prevention of diabetic neuropathy.

Diabetes Mellitus, Type 1↗
PubMed1997

A comparative study of isokinetic dynamometry and manual muscle testing of ankle dorsal and plantar flexors and knee extensors and flexors.

Muscle strength in neuropathic patients is usually evaluated clinically using manual muscle testing (MMT). Detection and grading of mild symmetrical muscle weakness using MMT is difficult partly because the examiner must take into consideration the normal variation in strength in relation to age, weight, height, and gender. In the present study assessment of the strength of ankle dorsal and plantar flexors and knee flexors and extensors with MMT and isokinetic dynamometry were compared in 108 patients, of whom 86 had diabetes mellitus and 22 had alcoholic liver cirrhosis. The isokinetic muscle strength of the patients was compared with the strength of 90 healthy control subjects, adjusted for the influence of age, weight, and height for both genders. MMT resulted in a significant underestimation of the frequency and severity of muscle weakness in both the ankle and the knee. In 28-41% of the comparisons, MMT misclassified the strength performance with one category or more (> 25%). Misclassifications were most frequent for the ankle plantar flexors.

Adult↗
PubMed1997

Growth in the external cranial base evaluated on human dry skulls, using nerve canal openings as references.

The purpose of this investigation was to measure on human dry skulls the postnatal widening and lengthening of the external cranial base, including the hard palate, using nerve canal openings as references. Forty-five Indian dry skulls were examined, 36 from children and 9 from adults. The age evaluation was made on the basis of dental development. The dimensions of the external cranial base were determined by direct measurements on the skulls and by measurements from photographs of the skulls. The study showed that growth in width of the external cranial base followed two distinct patterns. The two regions represent different embryologic developmental fields. The study points out that different growth patterns in these fields ought to be taken into account in future investigations of normal and pathologic craniofacial growth.

Adolescent↗
PubMed1996

Human palatal growth evaluated on medieval crania using nerve canal openings as references.

The purpose of this investigation was to measure postnatal lengthening and widening of the hard palate by use of nerve canal openings as references. The relationship of the dentition to the greater palatine foramina was also investigated. Thirty-nine medieval dry skulls were examined, 22 from children and 17 from adults. All crania were photographed at a 1.1 scale. The dimensions of the maxilla and the location of the dentition were determined from the photographs. The study showed that palatal growth in length in the sagittal plane takes place anterior to the greater palatine foramen. The growth increment in the area between the incisive foramen and the transverse palatine suture is more pronounced than the growth increment in the area between the transverse palatine suture and the greater palatine foramen. The distance from the greater palatine foramina to the posterior margin of the palate did not increase significantly with age. The growth in width seems to continue into adult life. The first permanent molars and the surrounding bone are moved forwards in relation to the greater palatine foramina during growth. The space for the developing maxillary premolars and molars therefore has to be obtained by growth in the transverse palatine suture.

Adult↗
PubMed1996

Treatment of spasticity with repetitive magnetic stimulation; a double-blind placebo-controlled study.

The effect of repetitive magnetic stimulation on spasticity was evaluated in 38 patients with multiple sclerosis in a double-blind placebo-controlled study. One group was treated with repetitive magnetic stimulation (n = 21) and the other group with sham stimulation (n = 17). Both groups were treated twice daily for 7 consecutive days. Primary end-points of the study were changes in the patients self-score, in clinical spasticity score, and in the stretch reflex threshold. The self-score of ease of daily day activities improved by 22% (P = 0.007) after treatment and by 29% (P = 0.004) after sham stimulation. The clinical spasticity score improved -3.3 +/- 4.7 arbitrary unit (AU) in treated patients and 0.7 +/- 2.5 AU in sham stimulation (P = 0.003). The stretch reflex threshold increased 4.3 +/- 7.5 deg/s in treated patients and -3.8 +/- 9.7 deg/s in sham stimulation (P = 0.001). The data presented in this study supports the idea that repetitive magnetic stimulation has an antispastic effect in multiple sclerosis. Future studies should clarify the optimal treatment regimen.

Activities of Daily Living↗
PubMed1996

Isokinetic muscle strength in long-term IDDM patients in relation to diabetic complications.

The isokinetic muscle strength in 56 IDDM patients with > 20 years of diabetes duration and in their individually sex-, age-, weight-, and height-matched control subjects was assessed. Peak torque of foot dorsal and plantar flexion and knee and wrist extension and flexion was measured. The neuropathic condition was assessed by a neurological disability score, a neuropathy symptom score, nerve conduction studies, and quantitative sensory examination. All results were summed to obtain a neuropathy rank-sum score for each patient. According to their renal albumin excretion, the patients were classified to have normo-, micro-, or macroalbuminuria. In addition, according to their retinal status, patients were classified as having no, simple, or proliferative retinopathy. The IDDM patients had a 21% reduction of muscle strength of both ankle dorsal (P < 1 x 10(-4)) and plantar flexors (P < 0.01), compared with control subjects. A 16% reduction of knee extensors (P < 0.005) and a 17% reduction of knee flexors (P < 0.01) was found. In contrast, muscle strength in wrist flexors and extensors was not significantly reduced (10 and 11%, respectively [NS]). In patients with the most severe weakness, muscle strength of the calf muscles was only 50% of the expected performance. Correlations were found between the neuropathy rank-sum score and the muscle strength of ankle dorsal (r = -0.66, P < 1 x 10(-7)) and plantar flexors (r = -0.51, P < 0.0005), knee extensors (r = -0.51, P < 0.0005) and flexors (r = -0.44, P < 0.005), and wrist flexors (r = -0.41, P < 0.005). No correlation was found for wrist extensors (r = 0). Neither were there any relationships between muscle strength at the ankle and knee and the degree of albuminuria or retinopathy. In conclusion, motor performance is substantially impaired in long-term IDDM patients, and the weakness is related to the presence of neuropathy but not to albuminuria or retinopathy per se.

Adult↗
PubMed1996

The effect of microwave heating on vitamins B1 and E, and linoleic and linolenic acids, and immunoglobulins in human milk.

Breast milk was treated with (1) conventional heating (in water bath) vs microwave heating; (2) microwave heating at two power levels (30% and 100%); (3) increasing final temperatures; and (4) microwave thawing vs refrigerator thawing and examined for changes in specific immunoglobulins to a pool of E. coli and poliovirus type 1 antigens, vitamins E and B1, and the polyunsaturated fatty acids linoleic and linolenic acid. Immunoglobulin activities were stable until final milk temperatures of around 60-65 degrees C were reached, and total inactivation occurred at 77 degrees C. Heating even to high final temperatures did not change contents of vitamins and polyunsaturated fatty acids. No differences in immunoglobulins and nutrients were demonstrated between microwave heating and conventional heating, and between power levels or thawing methods. The study shows that microwave heating of human milk can be performed without significant losses of examined immunoglobulins and nutrients, provided that final temperatures are below 60 degrees C.

Antibodies, Bacterial↗
PubMed1995

Motor pathway function in normoalbuminuric IDDM patients.

Central motor pathways were studied in 17 normoalbuminuric insulin-dependent diabetic (IDDM) patients who had been diabetic for more than 20 years, and compared with findings in 17 age-, sex-, and height-matched control subjects. The central motor conduction time was calculated from recordings of the compound muscle action potentials of the abductor pollicis brevis muscle after single transcranial and spinal root magnetic stimulation. The central motor conduction time from motor cortex to cervical spinal roots was 9.8 +/- 1.65 ms in diabetic patients and 10.1 +/- 1.48 ms in control subjects. In diabetic patients with neuropathy the central motor conduction time was 9.5 +/- 1.76 ms vs 10.1 +/- 1.56 ms in patients without neuropathy. The excitability of the motor pathways was studied by paired transcranial magnetic stimulation at interstimulation intervals of 30-1000 ms. In normal control subjects, an early facilitation of the amplitude of the compound muscle action potential at an interstimulation interval of 30 ms was found, while no facilitation was present in diabetic patients. In addition the compound muscle action potential latencies were prolonged at interstimulation intervals of 30-50 ms in diabetic patients. The changes of excitability did not correlate with the presence of peripheral neuropathy, metabolic control or diabetes duration. It is concluded that long-term normoalbuminuric IDDM patients have imparied excitability but normal central conduction time of the motor pathways.

Adult↗
PubMed1995

Dentofacial changes in Norwegian and Iowan populations between 6 and 18 years of age.

The purpose of this study was to compare the dentofacial changes in Norwegian and Iowan populations between 6 and 18 years of age. Comparisons of the absolute and incremental changes were made both longitudinally and cross-sectionally. The Norwegian sample consisted of 39 females and 35 males, the Iowa sample consisted of 15 females and 20 males, for whom complete sets of data were available for the period of the study. All subjects had a clinically acceptable occlusion and had not undergone previous orthodontic treatment. Descriptive statistics summarized the changes in 29 parameters. Longitudinal comparison of the growth curves evaluated the curve profiles and curve magnitudes for the two populations for both males and females. The analysis of variance was also used to compare the absolute and incremental changes at ages 6, 9, 12, 15, and 18 years. The study resulted in the following findings: 1. The longitudinal growth profile comparisons of the various dentofacial parameters indicated that the growth trends of the Norwegian and Iowa groups were essentially similar. 2. The comparisons of the growth profiles of the males and females from the two populations also indicated that there were no significant differences between the shape of their growth curves. 3. The comparisons of the curve magnitude, as well as the results of the cross-sectional comparisons, indicated that Norwegians had significantly greater maxillary and mandibular protrusion, and larger proclination of the upper and lower incisors than the Iowans.

Adolescent↗
PubMed1995

Agenesis of permanent incisors in a mediaeval maxilla and mandible: aetiological aspects.

A paleopathological maxilla and mandible with tooth agenesis were analyzed, focussing on the aetiology of the condition. The jaw material, derived from an adult mediaeval male, was examined by standard anthropological analyses, including radiography. In the maxilla there was agenesis of three permanent incisors and one premolar, and in the mandible of one permanent incisor and two permanent molars. Absence or marked reduction of the incisive foramen and the nasopalatine canal was found. The premaxillary area was reduced without general alveolar bone resorption. The pattern of tooth agenesis was similar to the pattern observed in contemporary individuals, except for the agenesis of one permanent maxillary central incisor. It is suggested that the pronounced lack of teeth in the maxillary anterior region is connected with deficient development of the premaxillary area of the nasopalatine canals and the incisive foramen. As the condition can be ascribed to deviations in the prenatal development, this investigation shows that embryological developmental patterns, which form the basis for the pattern of tooth agenesis, should be taken into account when evaluating dry bone pathology.

Anodontia↗
PubMed1995

Blood-brain barrier permeability of glucose and ketone bodies during short-term starvation in humans.

The blood-brain barrier (BBB) permeability for glucose and beta-hydroxybutyrate (beta-OHB) was studied by the intravenous double-indicator method in nine healthy subjects before and after 3.5 days of starvation. In fasting, mean arterial plasma glucose decreased and arterial concentration of beta-OHB increased, whereas cerebral blood flow remained unchanged. The permeability-surface area product for BBB glucose transport from blood to brain (PS1) increased by 55 +/- 31%, whereas no significant change in the permeability from brain back to blood (PS2) was found. PS1 for beta-OHB remained constant during starvation. The expected increase in PS1 due to the lower plasma glucose concentration was calculated to be 22% using previous estimates of maximal transport velocity and Michaelis-Menten affinity constant for glucose transport. The determined increase was thus 33% higher than the expected increase and can only be partially explained by the decrease in plasma glucose. It is concluded that a modest upregulation of glucose transport across the BBB takes place after starvation. Brain transport of beta-OHB did not decrease as expected from the largely increased beta-OHB arterial level. This might be interpreted as an increase in brain transport of beta-OHB, which could be caused by induction mechanisms, but the large nonsaturable component of beta-OHB transport makes such a conclusion difficult. However, beta-OHB blood concentration and beta-OHB influx into the brain increased by > 10 times. This implies that the influx of ketone bodies into the brain is largely determined by the amount of ketones present in the blood, and any condition in which ketonemia occurs will lead to an increased ketone influx.

Adult↗
PubMed1995

Scanning electron microscopy, a useful tool in forensic dental work.

In selected cases there is a need for microscopic information found on the surface of tooth specimens. Scanning electron microscopy is the method of choice. Based on the knowledge of the structural organization of the mineralized dental tissues differential diagnoses of physical and chemical changes can be made. It is suggested that the forensic dental profession cooperates in establishing a collection of reference material illustrating different traumas to enamel and dentin, deposits on teeth and the structure of restorative dental materials as they will appear after some years in position on a tooth. Four different cases are presented.

Animals↗
PubMed1994

A Danish family with limb-girdle muscular dystrophy with autosomal dominant inheritance.

We describe a Danish family of five generations showing a slowly progressive autosomal dominant limb-girdle myopathy with onset in early childhood. Three patients from two generations were examined and showed weakness predominantly of the proximal muscles of upper and lower extremities. Early contractures of wrist, tight heel cords, metacarpophalangeal and interphalangeal joints were present. Walking ability was partly preserved. Serum creatine kinase activity was normal or slightly elevated. EMG and biopsy showed mildly myopathic changes. Magnetic resonance images of the thigh showed severe atrophy of all compartments but with musculus semimembranosus, sartorius, and gracilis relatively preserved. This myopathy has a clinical picture similar to the Bethlem myopathy.

Biopsy↗