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Biomedical subjects

P Halonen

Publications and source records attributed to P Halonen.

At least 109 records · Page 6Linked to original sources
PubMed1988

The conduction velocities of peripheral nerve fibres conveying sensations of warming and cooling.

With the current practice of measuring thresholds for warming and cooling separately, the question of the exact nature of afferents subserving these sensations assumes new importance. Experiments to measure reaction times to warming and cooling stimuli at two sites on the lower limb are described. The conduction velocity for each sensation was estimated from the conduction distance and conduction time in the limb. The estimated mean conduction velocity for warming was 0.5, SD 0.2 m/s and cooling 2.1, SD 0.8 m/s. These figures confirm that the sensation of warming is conveyed in unmyelinated and cooling in small myelinated peripheral nerve fibres.

Adult↗
PubMed1987

Purification of adenovirus hexon protein by high-performance liquid chromatography.

Adenovirus (Type 2)-infected HeLa cells were sonicated and treated with 1,1,2-trichlorotrifluoroethane. The water-soluble extract was ultracentrifuged and the supernatant, containing the dissociated proteins, was subjected to anion-exchange high-performance liquid chromatography on a Mono Q column in 50 mM bis-Tris-HCl (pH 6.5). Elution with a linear salt gradient resulted in a major peak, containing the hexon protein.

Adenoviridae↗
PubMed1987

Functional disturbances of the masticatory system related to temporomandibular joint involvement by rheumatoid arthritis.

Several theories have been proposed concerning the aetiology of dysfunction of the temporomandibular joint (TMJ). To analyse the relationship of radiographic changes to clinical signs and symptoms of TMJ dysfunction, the present study was conducted in subjects highly predisposed to TMJ involvement, i.e. in patients with rheumatoid arthritis (RA). The aim of the study was to estimate the frequency of disturbances in the masticatory system of RA patients. In addition, the relationship between TMJ abnormalities and the signs and symptoms of dysfunction was investigated. The study consisted of sixty patients with RA and forty control subjects. Asymptomatic subjects were more frequent in the RA group than in the controls. Muscle pain during palpation was recorded in 53.3%, clicking in 53.3%, crepitation in 21.7%, reduced movement capacity of the TMJ in 41.7%, and restricted mouth opening in 31.7% of the RA patients examined. In the control group the most common symptoms and signs were clicking (57.5%), muscle pain during palpation (57.5%) and restricted opening (25.0%). Normal radiographic appearance of the TMJ in RA patients was found in 31.7%. Minor changes comprised 31.7%, moderate changes 21.6%, and severe changes or total loss of the condyle 15.0%. In the control group a normal joint was detected in 87.5%, while minor changes were encountered in 7.5%, and moderate or severe changes only in 5.0%. No relationship was found between Helkimo's anamnestic, clinical or occlusal indices and the severity of the disease graded according the criteria outlined by the American Rheumatism association (ARA). In the ARA group the frequency of signs and symptoms of dysfunction increased with the destructive changes in the TMJ area. In the controls, muscle pain during palpation and clicking sounds in the TMJ were most commonly connected with normal radiographic appearance of the TMJ. In the discriminant analysis the most discriminating factors were crepitation, tenderness to palpation of muscles and movement of TMJ.

Adult↗
PubMed1987

A study of haemostasis following the use of high doses of hydroxyethyl starch 120 and dextran in major laparotomies.

The safety of plasma expanders, hydroxyethyl starch 120 and dextran 70, administered in the highest recommended doses (20 ml/kg) as adjuncts of component therapy of surgical blood loss was studied in patients undergoing major abdominal surgery and compared with a group receiving 4% albumin solution for initial haemodilution and whole blood for further blood loss replacement. Each group consisted of five patients in a relatively severe surgical, but good general condition including a normal haemostatic function and serum albumin level. The dilutional effect of the expanders on serum albumin and prothrombin-proconvertin level was observed during the day of operation. On the first postoperative day these values were equally low in all groups. Platelet count and bleeding time remained on a safe level throughout the study in all groups. Partial thromboplastic time values were unchanged. The factor VIII procoagulant (C), related antigen (R:Ag, vWF:Ag) and ristocetin cofactor levels, which were high preoperatively due to the underlying disease, remained at a safe level throughout the study. The increase in factor VIII related antigen associated with the hypercoagulable state induced by the surgical trauma was prevented by the plasma expanders. We conclude that dextran and hydroxyethyl starch can be used safely in a dose of 20 ml/kg in component therapy of surgical blood loss, provided that haematocrit is kept at an acceptable level, attention is paid to the postoperative hypoproteinaemia, and the patient has a normal haemostatic function preoperatively.

Adult↗
PubMed1987

Evaluation of risk factors in intraoperative bleeding tendency.

The effects of preoperative administration of non-steroidal anti-inflammatory drugs, intraoperative infusion of plasma expanders, type of anaesthesia, blood group and certain coagulation parameters on the bleeding tendency of 354 patients undergoing abdominal and urological surgery were analyzed. The bleeding tendency was estimated by the surgeon at the end of the operation. The preoperative use of non-steroidal anti-inflammatory drugs was associated with an increased bleeding tendency (p less than 0.05). Excessive bleeding was more common in patients who had received dextran intraoperatively, but did not reach statistical significance. Other potential risk factors were not associated with increased bleeding tendency. Two months after the operation, factors VIII:C and vWF:Ag of 32 patients were analyzed. Increased bleeding tendency was not more common in patients with low F VIII activity associated with blood group O, than in others. We conclude that the disorder of primary haemostasis caused by non-steroidal anti-inflammatory drugs is common and causes increased bleeding tendency in surgical patients. If the patient has additional risks of haemostasis, or if accurate surgical haemostasis is of particular importance, it seems justified to withdraw non-steroidal anti-inflammatory drug medication before operation.

Adult↗
PubMed1986

Detection of low molecular weight cysteine proteinase inhibitors by time-resolved fluoroimmunoassay.

A time-resolved fluoroimmunoassay was developed for the detection of 3 human low molecular weight cysteine proteinase inhibitors, ACPI (cystatin A), NCPI (cystatin B), and gamma-trace (cystatin C). Polystyrene tubes or polystyrene microtitration strips were used as solid phase. The rabbit anti-inhibitor immunoglobulins were used as the capture antibody, and, when labelled with europium, also as the detector antibody. The threshold sensitivity of the tests was 0.1 ng/ml for NCPI and 1 ng/ml for the others. All the 3 cysteine proteinase inhibitors, ACPI, NCPI, and gamma-trace, were detected in pooled serum samples of patients with kidney failure. gamma-Trace seemed to be quantitatively the major and ACPI the minor inhibitor. No other low molecular mass cysteine proteinase inhibitor was detected after isoelectric focusing of the 12 kDa area of gel filtered human serum.

Antibody Specificity↗
PubMed1986

Synthesis of measles virus-specific IgM antibodies and IgM-class rheumatoid factor in relation to clinical onset of subacute sclerosing panencephalitis.

Thirty-seven serum and 37 cerebrospinal fluid (CSF) specimens from 27 patients with subacute sclerosing panencephalitis (SSPE) were tested for measles virus (MV) IgM antibodies and IgM-class rheumatoid factor (RF) to determine if a temporal relationship exists between SSPE onset and these immunoglobulins. Sensitive solid-phase radioimmunoassays were used for immunoglobulin detection. Five of six MV IgM-positive CSF, both MV IgM-positive sera and six out of eight sera with elevated RF levels were collected within 1 yr of SSPE onset. Also collected during this time were six other sera having high binding in the MV IgM assay, which was not due to MV-specific IgM antibodies. Two of these sera had as high or higher binding of IgM to a Vero cell control antigen, suggesting involvement of an IgM-class autoantibody. The other four sera had false-positive MV IgM assay results due to RF interference. RF interference was dependent on both the titer and avidity of the MV IgG antibodies involved. Three conclusions can be drawn from these results. First, MV IgM antibodies and elevated RF levels are not markers for acute SSPE, despite the tendency for their synthesis at this stage of the disease. Second, immunoassay analysis of viral IgM antibodies must employ an appropriate control antigen to account for background IgM binding. Finally, even if RF levels are normal or near normal, a false-positive IgM immunoassay result can still occur if antigen-specific IgG antibodies in the same sample have the right combination of titer and avidity.

Antibodies, Viral↗
PubMed1986

Quantitative vibration perception thresholds in healthy subjects of working age.

Quantitative determinations were made of vibration perception thresholds (VPTs) at six different measurement sites in 202 healthy subjects of working age (16-68 years). Measurements were made with a commercially available device, the frequency of vibrations being 100 Hz. The temperature of the skin at the measurement sites was also determined. The effect of temperature on VPT values was evaluated separately in eight test subjects. In addition, determinations were made of intraindividual variations in VPT values and it was found that there was an almost 100% variation under identical conditions. Variation in VPTs caused by temperature was only slightly greater than intraindividual variation from day to day. It did not seem to be necessary, for the making of measurements, to take into account variations of temperature within physiological limits. VPT was found to increase exponentially with age, more steeply among men than women. In practice, it is most important when making VPT measurements to take into account the age and sex of the subject and possibly also to allow for thresholds slightly higher than usual with subjects engaged in physical work. An important field of application for this method is in occupational health services, where there is a need for a simple and reliable screening test when attempting to diagnose polyneuropathy. The method is also very suitable for determining the neurotoxic effect of different drugs.

Adolescent↗
PubMed1986

Assay of measles virus IgM and IgG class antibodies by use of peroxidase-labelled viral antigens.

Purified measles virions, nucleocapsid protein and crude lysate of measles infected cells were labelled with horseradish peroxidase, and used for the detection of IgM and IgG antibodies to measles virus by direct enzyme immunoassay. The assays consisted of three layers: anti-human IgM or IgG immunoglobulins on solid-phase, test serum specimen and enzyme labelled viral antigen. For the expression of the results, a standard curve was included in each test and the O.D. values were changed to arbitrary antibody units. Specificity and sensitivity of the assays were compared with indirect EIAs. The specificity studies included a collection of serum specimens containing either rheumatoid factor, antinuclear antibodies or IgM antibody specific for other viruses. The assays proved both reliable and simple to perform and sensitivity was slightly higher than that for indirect EIAs. However, specificity was dependent on the purity of the viral antigens. When crude infected cell lysate antigen was used, some nonspecific results were obtained, particularly with serum specimens containing antinuclear antibodies. When virion or nucleocapsid protein were used, no nonspecific reactions were obtained.

Antibodies, Antinuclear↗
PubMed1986

Quantitative vibratory perception thresholds of healthy and epileptic children.

Quantitative vibratory perception threshold (VPT) measurements were performed on 102 healthy children and 79 children receiving anti-epileptic medication. Their ages ranged from three to 16. The VPTs correlated significantly with age and height. The rise in VPT with age may be associated with decreased receptor density. The level of mental alertness seemed to have no significant effect on vibratory perception. Only three of the children on anti-epileptics showed elevated VPTs. On the basis of this study, epileptic children seem to be free of the adverse effects of medication which occur later in adulthood. Children as young as three or four are quite capable of co-operating in this examination. The method can be recommended for use in follow-up studies of children and as a diagnostic aid when a disturbance of the sensory tract is suspected.

Adolescent↗
PubMed1986

Vibratory perception thresholds in shipyard workers exposed to solvents.

Vibratory perception thresholds were determined for 90 subjects working at a shipyard with industrial solvents. The duration of exposure varied from 1 to 44 years (mean 19.6 years). Four of the men but none of women had bilaterally significantly increased thresholds in the lower limbs. In addition, seven subjects had increased thresholds in the upper extremities only. Fifteen subjects were further examined at a neurophysiological laboratory to determine the degree of possible peripheral polyneuropathy. The following measurements were made at the laboratory: motor and sensory conduction velocities, electromyography and heart rate variation during normal and forced breathing. The laboratory investigations revealed abnormalities in most of the subjects with increased vibratory perception thresholds in the lower limbs. On the other hand the laboratory measurements were normal for all subjects with increased thresholds in the upper limbs only. It is concluded that when peripheral polyneuropathy is suspected, quantitative vibratory perception threshold measurement is an easily applicable screening method for selecting subjects for further laboratory investigations.

Adult↗
PubMed1986

Vibratory perception threshold in patients with mild multiple sclerosis.

The vibratory perception threshold (VPT) was measured bilaterally on both the upper and lower extremity in 69 patients with mild multiple sclerosis. In the case of the lower extremities the VPT measurements were closely correlated with qualitative vibratory perception measurements performed with a tuning fork; in the upper extremities the association was weak. The VPT was abnormal at least in one extremity in 38% of the patients. Quantitative VPT measurement seem to be a suitable technique for the detection of sensory symptoms of central origin.

Adolescent↗
PubMed1986

Viral findings in children under the age of two years with expiratory difficulties.

Viral findings were prospectively studied in lower respiratory tract infections in small children with and without expiratory difficulties. On first admission, a viral aetiology was found in 71 of 127 children (56%). On re-admission, a viral etiology was found in only two of 31 cases (6%). Respiratory syncytial viruses (RSV) were responsible for 71% of the cases with viral diagnoses. A recently-developed method for the direct detection of viral antigens in nasopharyngeal specimens by radio-immunoassay was more sensitive than complement fixation serology, especially in patients aged less than six months. Viral diagnosis was reached using this new method alone in 43% of infections caused by RSV and in 27% of infections caused by other viruses. In children under six months, RSV were found in 89% by direct antigen detection and in 22% by serology. We suggest that direct antigen detection should be used as the primary virological method in small children with lower respiratory tract infections. The aetiological agents were the same in cases with and without expiratory difficulties, RSV being found in about 40% of children in both instances. It is concluded that host factors are critical to the development of expiratory difficulties.

Adenoviruses, Human↗
PubMed1986

C reactive protein in the evaluation of febrile illness.

We studied prospectively 154 febrile children to determine the diagnostic value of the quantitative serum C reactive protein concentrations (CRP). Children with acute otitis media, acute tonsillitis, or treated with antibiotics during the two previous weeks and infants less than 2 months of age were excluded. Ninety seven children were from private paediatric practice and 57 were patients who had been admitted to hospital. The comparison group consisted of 75 children with confirmed bacterial infections whose CRP values were recorded retrospectively. In the study group 35 (23%) children had a confirmed viral infection, 92 (59%) had a probable viral infection as judged from the clinical picture and outcome of the illness, and 27 (18%) had a bacterial or probable bacterial infection. When the duration of the disease was more than 12 hours and the CRP value less than 20 mg/l, all children had a confirmed or probable viral infection. Nine children (one from the study group and eight from the comparison group) were found to have a septic infection and a CRP value of 20 mg/l or less. In all these cases, however, the duration of the symptoms was less than 12 hours. In addition CRP less than or equal to 20 mg/l was found in five (14%) children with urinary tract infection in the comparison group. CRP values of 20-40 mg/l were recorded in children with both viral and bacterial infections. A CRP value greater than or equal to 40 mg/l detected 79% of bacterial infections with 90% specificity. Our data show that determination of serum CRP concentrations is a valuable tool in evaluating children who have been ill for more than 12 hours.

Adolescent↗
PubMed1986

Myelin basic protein antibodies in catatonic schizophrenia.

Myelin basic protein (MBP) antibodies were determined by solid-phase radioimmunoassay in the serum and cerebrospinal fluid of 10 patients with catatonia, 10 patients with other forms of schizophrenia, and 10 psychiatrically healthy controls. The mean counts per minute (cpm) value of serum anti-MBP antibody of the catatonia group was significantly higher than that of the patients with other forms of schizophrenic psychoses (p less than .05). No significant differences were observed among the cpm values of the CSF specimens from the three patient groups. The hypothesis of a central virus-induced immunologic aberration in catatonic schizophrenia is discussed.

Adult↗
PubMed1985

Detection of adenoviruses in stool specimens by nucleic acid spot hybridization.

Nucleic acid hybridization was used for the detection of adenovirus DNA in stool specimens, and the results were compared with those obtained by a radioimmunoassay (RIA) for adenovirus hexon antigen. DNA from 40 specimens, 18 of which were positive by RIA, were spotted onto nitrocellulose filters and analyzed by hybridization using radioactively labeled adenovirus-2 DNA or a cloned DNA fragment from enteric adenovirus-41 as probes. With the adenovirus-2 DNA probe, 15 of the 18 RIA-positive specimens were also positive in the hybridization assay, and one of the RIA negative specimens was also scored as positive. The cloned adenovirus-41 fragment gave a positive signal with five specimens, all of which were also detected with the adenovirus-2 DNA probe. The results show that hybridization is an alternative method for detection of adenovirus in stool specimens. The sensitivity of the assay is comparable to that of the RIA.

Acute Disease↗