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Biomedical subjects

B Johansson

Publications and source records attributed to B Johansson.

895 records · Page 50Linked to original sources

Penile human papillomavirus carriage among men attending Swedish STD clinics.

Using the polymerase chain reaction (PCR) technique, we found that up to 84% of 228 men consecutively attending two Swedish STD clinics harboured human papillomavirus (HPV) types 6 or 16. Mean age of the patients was 28 years (range 17-58); 70% were between 17 and 30 years old. Among men without a previous history of, or contact with, condylomata the frequency of HPV 6 detection was 76% using the PCR/dot blot (DB) analysis and 43% with the PCR/agarose gel (AG) technique. The corresponding figures for HPV 16 were 46% and 13%, respectively. These figures were comparable to those found in men with existing condylomata infection or sexual exposure to a partner with condylomata. Although the test group represents a selected high-risk population for STD including HPV, our results indicate that a high frequency of occult HPV carriage exists among sexually-active males. The significance of these findings is discussed.

Adolescent↗

Luminance and color contrast sensitivity and VEP latency in subjects with normal and defective binocularity.

Luminance contrast sinusoidal gratings (spatial frequencies 1, 2 and 4 cycles/degree) were compared with the corresponding color contrasting patterns (along the protan, deutan and tritan axes) to see whether they demonstrated normal binocular function in humans, and distinguished between normals and persons with defective binocularity. Contrast sensitivity and transient pattern VEP latency (on-responses) were measured in normals (n = 11, median age 36, range 12-46 years) and subjects with no stereopsis (n = 6, median age 13, range 8-38 years). The normal group had significantly higher contrast sensitivity with binocular stimulation for all patterns except tritan contrast gratings of 2 and 4 c/deg. The stereo-deficient group showed no higher binocular contrast sensitivity for any pattern. Differences between groups were significant with all gratings of 4 c/deg, and also with protan and deutan contrast gratings of 2 c/deg. In the normal group, binocular VEP latency was significantly shorter than the monocular with protan contrast gratings of 2 c/deg and tritan contrast gratings of 1 and 2 c/deg. Differences between the normal and the stereo-deficient groups were significant for all color contrast patterns of 2 c/deg; and tritan contrast gratings of 1 c/deg. We conclude that color contrast sensitivity and VEP measurements are potentially useful for demonstrating binocular function, and for separating normals from stereo-blind subjects. Color contrast patterns however are less effective than the corresponding luminance contrast patterns in evoking cortical potentials.

Adolescent↗

Human papillomavirus deoxyribonucleic acid in cervix only detected in girls after coitus.

In a prospective cohort study on the prevalence of HPV in a group of female Swedish students, we obtained repeated cytological specimens during a period of 2 years, for cytological diagnosis and PCR detection of HPV. The group comprised 98 girls, sampled between 15 and 17 years, and 82 of them completed the study. The girls were also followed every sixth month by a structured face-to-face interview regarding sexuality. Only the sexually experienced girls harboured HPV-DNA in the cervix with a cumulative prevalence of 37% and HPV16 was the most common type encountered. Almost half of the infected girls were lacking any clinical or subclinical signs of HPV infection. There was a positive correlation between the presence of HPV and the number of coital partners. The time period since coitarche also had importance for the HPV detection rate.

Adolescent↗

Time sequence of degeneration pattern of the organ of Corti after acoustic overstimulation. A light microscopical and electrophysiological investigation in the guinea pig.

In order to obtain information about the sequence of events leading to degenerative changes in the cochlea after acoustic trauma, a systematic LM study was performed in the guinea pig organ of Corti. The results were correlated with measurements of CAP N1 thresholds from the same animals. Twenty pigmented guinea pigs were used in the study. Ten of these animals were exposed to a 3.85 kHz pure tone with an intensity varying between 108 and 120 dB SPL for 22.5 to 360 min and were sacrificed after 4 weeks. Eight animals were exposed to 120 dB SPL for 22.5 min and sacrificed at regular intervals after exposure, viz. 5 min, 4, 24 h and 5 days. Prior to sound exposure the animals in the 4-week group were implanted with a permanent round window electrode for measurements of CAP N1 thresholds. The study indicates that the degeneration and reparative processes are not entirely completed after 4 weeks. The development of holes in the reticular lamina may result in further degeneration of cells bilateral to the initial maximum damage. Darkly stained cells seem to be activated in the reparative process in the organ of Corti. Local appearance of dendritic macrophages in the organ of Corti indicate the existence of a local mechanism for disposal of degeneration products from the organ of Corti. The retrograde degeneration of radial nerve fibres seems to be closely associated with that of the pillar cells. A close correlation between structural hair cell damage and CAP N1 threshold shift was found in the region of the organ of Corti corresponding to the exposure frequency. The TS 5 min, 4 h and 24 h after exposure showed a close correlation with swellings in the afferent nerve endings below the IHC in the area of maximum damage and basalwards.

Acoustic Stimulation↗

Frequency discrimination for bands of noise.

Recoding of speech in order to improve discrimination for profoundly deaf people has been tried in various ways. One of these is frequency transposition of voiceless consonants. Some authors report positive and very promising results. Others, however, have not found any significant difference when using control groups with normal amplification. One reason might be a poor frequency discrimination. Is it possible to establish what minimum hearing capacity the listener must show for a successful use of frequency transposition? Using noise bands with different Q factors and varying the levels, the thresholds as minimum midfrequency shift have been measured. Great individual variations have been shown. There is a significant difference between (1) threshold values at different Q factors, (2) threshold values at different frequencies, and (3) threshold values for increasing and decreasing frequency, position of deltaf. There is a significant interaction between (1) frequency and position of deltaf, (2) Q factor and position of deltaf, and (3) between Q factor and frequency. There is also a significant triple interaction between Q factor, frequency, and position of deltaf.

Acoustic Stimulation↗

Immunodeficiency and prognosis in patients with non-Hodgkin's lymphomas.

Monocyte depleted blood lymphocyte subpopulations, their functions and relation to prognosis were studied in 68 untreated adult patients with non-Hodgkin's lymphomas classified according to the Kiel nomenclature. The median observation time was 48 months (range 41-60). The mean total blood lymphocyte and T (SRBC-rosetting) cell counts were significantly decreased as compared with age-matched controls (n = 57). Twenty-five per cent of the patients had a monoclonal blood B lymphocyte population. The spontaneous lymphocyte DNA synthesis, measured as incorporation of 14C-thymidine, was increased and the response to mitogen and antigen stimulation was decreased. Blood lymphocyte counts and functions before treatment were not related to the rates of remission or survival.

Adult↗

HIV-1 nef mutations and clinical long-term nonprogression. A molecular epidemiology study.

OBJECTIVES: To analyze HIV-1 nef gene mutations in a cohort of Italian and Swedish long-term nonprogressors (LTNP) and to investigate whether particular amino acid substitutions are associated with LTNP. STUDY DESIGN/METHODS: nef alleles from 21 LTNP and 8 progressor controls were amplified by polymerase chain reaction (PCR) and sequenced. The amino acid sequences were compared with the previously reported sequences of 16 North American LTNP and of 28 patients with progressive infection. RESULTS: An untruncated intact open reading frame was observed as major sequence in all LTNP and controls. None of the amino acid substitutions in known biologically functional sites was linked to LTNP. A valine/isoleucine at the variable position 11 was associated with both European (P = .0001) and American (P = .001) LTNP. The interpatient nef variation was lower among European LTNP (P = .002) than in European progressor controls. CONCLUSIONS: Nef amino acid heterogeneity is lower among LTNP, probably reflecting the lower HIV-1 replication rate. Nef gene defects appear uncommon in both Swedish and Italian LTNP, although the presence of a valine/isoleucine at position 11 is statistically associated with a lower probability to progress to disease.

Adolescent↗

Implants and sinus-inlay bone grafts in a 1-stage procedure on severely atrophied maxillae: surgical aspects of a 3-year follow-up study.

This 3-year follow-up study compares implant treatment in 39 1-stage sinus-inlay block-grafted patients (study group) with 37 patients treated without bone grafting (reference group), all of whom were edentulous in the maxilla and were treated over the same time period. The cumulative success rate (CSR) of implant stability after 3 years in the study group was 75.3% in grafted areas and 82.2% in non-grafted areas. The CSR after 3 years in the reference group was 93.1%. The mean marginal bone resorption after 3 years of loading was 1.4 mm in grafted areas and 1.6 mm in non-grafted areas in the study group and 1.1 mm in the reference group. Complications noted during the postoperative healing periods correlated significantly with implant failures later on (P < .05). Since prosthesis stability (CSR) after 3 years was 94.9% in the study group and 97.3% in the reference group, it can be concluded that 1-stage sinus-inlay block grafts can be regarded as a safe method with a predictable outcome for use on patients with severely atrophied edentulous maxillae, although increased failure rates are to be expected for implants placed in bone-grafted regions.

Aged↗

A prospective randomized study of 1- and 2-stage sinus inlay bone grafts: 1-year follow-up.

The purpose of the present study was to compare the success of and surgical differences between 1- and 2-stage sinus inlay bone grafts and implants after 1 year in function. The individual risk for implant failure in grafted areas among 1-stage patients was about twice the risk in 2-stage patients (odds ratio 2.3, CI 0.6; 8.5). The risk for implant failure in non-grafted areas was significantly lower (P < .05) than in grafted areas, regardless of the technique used. Forty edentulous patients, selected according to strict inclusion criteria from consecutive referrals, were allocated to one or other of the 2 sinus-inlay procedures. Twenty patients received bone blocks fixed by implants to the residual alveolar crest in a 1-stage procedure (group 1). In another 20 patients, particulated bone was condensed against the antral floor and left to heal for 6 months before implants were placed (group 2). An almost equal number of implants was placed in the patients of each group, 76 in the 1-stage procedure and 74 in the 2-stage procedure. Additionally, 72 and 66 implants were placed in the anterior non-grafted regions of group 1 and group 2 patients, respectively. After 1 year in function, a total of 20 implants failed in 1-stage patients, versus 11 in 2-stage patients. Sixteen and 8 implants, respectively, of these were placed in grafted bone. All but one 1-stage patient received the planned fixed prosthetic restorations, but 1 restoration was redesigned after the first year in function because of a functionally unacceptable prosthetic design. At the 1-year follow-up, one 2-stage patient lost her prosthesis as the result of multiple implant failures. Bruxism and postoperative infections were the only parameters that could be related to implant failure, however, depending on the statistical method used.

Adult↗

Renal parenchymal volume in children. Normal values assessed by ultrasonography.

Forty-three children with normal urograms and with kidneys of normal size regarding length, area and parenchymal thickness were examined using a water-delay computerized ultrasonographic equipment. Renal parenchymal volumes were calculated and related to body weight. The correlation coefficient was 0.92. The renal parenchymal volume of the left kidney was significantly larger than that of the right kidney (p less than 0.001). For practical purposes they should, however, be assumed to be of equal size, 2.0 +/- 0.3 cm3/kg body weight.

Body Weight↗

Urographic renal size in acute pyelonephritis in childhood.

Eighteen children with acute pyelonephritis were investigated by urography at the time of and about two months after the acute infection. Renal size was evaluated as renal length and parenchymal area. During the acute infection renal size was larger than at the follow-up examination two months later. In conclusion, urography performed in close connection with the acute pyelonephritic infection gives an overestimation of renal size.

Acute Disease↗

Human papillomavirus in cell samples from Stockholm Gynecologic Health Screening.

We compared the results of cytologic screening of 500 women in the Stockholm Gynecologic Health Control with human papillomavirus (HPV) detection by polymerase chain reaction (PCR) and in situ hybridization (ISH). There were two main age groups, one 30 years and younger and the other 40 years and older. There were relatively more women with HPV infection in the younger group than in the older one (15.7% as compared to 11.1%), but the difference was not significant in our material. Most cases (8/12) with cytologic atypia were HPV positive by PCR. HPV type 16 was most common, followed by types 31 and 18. HPV of unknown types was detected in 43.7% of HPV-positive cases. There was excellent agreement between PCR and ISH in detecting and typing HPV.

Adult↗