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Biomedical subjects

B L Jensen

Publications and source records attributed to B L Jensen.

At least 91 records · Page 5Linked to original sources
PubMed1984

Reduced tooth size in 45,X (Turner syndrome) females.

Mean values and variances of deciduous and permanent tooth dimensions were compared between 121 45,X (Turner syndrome) females and 171 control subjects to clarify the role of the X chromosome on dental development. Although deciduous molars tended to be smaller than normal in 45,X females, there was no evidence of a reduction in tooth size for deciduous anterior teeth. In the permanent dentition, all mesiodistal dimensions were significantly smaller in 45,X females but only some of the buccolingual dimensions were smaller. The findings for deciduous tooth-size may reflect a sampling effect related to the extremely high frequency of spontaneous abortion in 45,X individuals. Results for permanent teeth are consistent with the concept of a decrease in enamel thickness in 45,X females.

Dental Enamel↗
PubMed1983

Longitudinal study of body height, radius length and skeletal maturity in Danish boys with cleft lip and palate.

Body height, radius length and skeletal maturity were registered longitudinally in 48 boys with combined cleft lip and palate (CLP) and compared with measurements in a non-cleft control group. Age range was from 6 to 20 yr. Skeletal maturity was evaluated according to the TW2 method. Distance and velocity curves for radius length and body height were determined by means of a computer program which for each month calculated the median and percentiles of the distribution. Compared to the control group the CLP boys were slightly shorter from 6 to 18 yr of age. The velocity curves revealed that pubertal growth maximum occurred on an average 6 months later in the CLP boys and that the pubertal growth spurt was less marked. However, the total growth period was prolonged thus enabling the CLP group to catch up with the control group. Skeletal maturity was retarded during the whole period when compared to normal children. It is suggested that the early feeding problems and recurrent infections of the upper airways combined with the surgical procedures account for an essential part of the delay in the present CLP group.

Adolescent↗
PubMed1982

Lymphocytic choriomeningitis virus-induced immunosuppression: evidence for viral interference with T-cell maturation.

Acute lymphocytic choriomeningitis virus (LCMV) infection is associated with general immunosuppression which develops during the second week of the infection and persists for several weeks. In the present study, the ability of LCMV-infected mice to mount a cytotoxic T-lymphocyte response was investigated in a transplantation assay, using LCMV-immunized mice as recipients. By this means it was possible to evaluate the T-cell responsiveness of the acutely infected mice separately. Our results revealed a marked depression of the T-cell function temporally related to immunosuppression in the intact mouse. Furthermore, this hyporesponsiveness could not be explained as an effect of suppressor cells. Occurring shortly before these changes were a drastic decrease in cortical thymocytes and a reduction in T-cell progenitors in the bone marrow and spleen. Our findings are consistent with the assumption that a numerical deficiency of immunocompetent T-cells due to viral interference with T-cell maturation plays an important role in LCMV-induced immunosuppression.

Animals↗
PubMed1982

Comparison of craniofacial morphology in infants with incomplete cleft lip and infants with isolated cleft palate.

The craniofacial morphology was compared in 30 infants with incomplete left-sided cleft lip and 30 infants with isolated cleft palate. Cephalometric radiographs were obtained prior to any surgical management at 2-3 months of age in the lateral, anteroposterior and axial projections. Compared to the cleft lip group, the infants with isolated cleft palate showed the following characteristics: short anterior cranial base, short maxilla, reduced posterior maxillary height, reduced dimensions of the mandible--especially mandibular length--, narrow naso- and oropharyngeal airway. The cleft lip group had larger interorbital width and symmetry deviations in the anterior art of the maxilla. It was concluded that already at two months of age and prior to any surgical interference significant differences in craniofacial morphology distinguished the group with clefts of the secondary palate from the group with clefts of the primary palate.

Cephalometry↗
PubMed1981

Abnormalities of the cranial base in cleidocranial dysostosis.

The purpose of the present investigation was to describe the size, shape, and morphologic characteristics of the cranial base in adult patients with cleidocranial dysostosis in an attempt to contribute to an improved understanding of the syndrome. The sample comprised seventeen patients with cleidocranial dysostosis, eight males and nine females aged 16 to 46 years. The morphology was evaluated from lateral cephalometric radiographs and midsagittal tomograms of the cranial base. The size of the anterior and posterior cranial base and the cranial base angle were compared to normative data. In addition, a qualitative screening for abnormal morphologic traits in the cranial base was carried out. The anterior and posterior cranial base was significantly shorter and the cranial base angle smaller in the syndrome groups than in the control groups. Patients with cleidocranial dysostosis exhibited high frequencies of anomalous traits in the cranial base, the most striking being a distortion of the clivus. In 82 percent the clivus was flexed, with the convexity toward the endocranium. All patients exhibited bulbous dorsum sellae, and 47 percent had small pituitary fossae. It is suggested that bone remodeling showed less resorption than normal in the craniofacial region of patients with cleidocranial dysostosis.

Adolescent↗
PubMed1980

Concanavalin A-mediated in vitro activation of a secondary cytotoxic T-cell response in virus-primed splenocytes.

In a recent report it was shown that what appeared to be secondary cytotoxic T cells could be obtained from lymphocytic choriomeningitis virus (LCMV)-primed splenocytes after stimulation in vitro with the non-specific T cell mitogen concanavalin A (Con A). The present experiments attempt to characterize further these effector cells and, in particular, to establish whether the Con A-activated cytotoxic effectors are qualitatively different from the secondary cytotoxic T cells induced by restimulation with the homologous antigen. It was found that: (1) in vitro activation with Con A could be obtained with populations harvested between 13 days (the earliest tested) and at least 300 days after priming; (2) cytotoxicity was independent of the presence of carried-over Con A in the cytotoxicity assay; (3) cytotoxicity was dependent on close association between activated T cells and target cells, since no evidence was found to indicate a role for other cell types or soluble (cytotoxic or arming) factors; (4) cytotoxicity was specific with regard to both virus and 'self'. By comparison with previous data on LCMV-induced cytotoxic T cells, it is concluded that Con A induces the generation of cytotoxic T cells from LCMV-primed splenocytes, which, by the criteria used, are indistinguishable from virus-induced secondary cytotoxic T cells. The implications of these findings are discussed.

Animals↗
PubMed1977

Variable expressivity of Crouzon's syndrome within a family.

Three individuals in two generations affected with Crouzon's syndrome are reported. The proband, a 10-year-old boy, had been diagnosed until the age of 4. His 3-year-old sister had not been diagnosed previously and his mother was unaware of having the syndrome and had never received any genetic counseling. The individuals are reported with emphasis on clinical and roentgencephalometric variation. The ultimate goal in teratolgoy is prevention. Currently one of the most important factors related to prevention is genetic counseling in conditions with well-documented modes of inheritance. The present report describes how the variable expressivity of Crouzon's syndrome within a family had caused diagnostic problems and consequently had delayed genetic counseling.

Cephalometry↗
PubMed1976

Craniofacial morphology in the nevoid basal cell carcinoma syndrome.

A roentgencephalometric analysis of eight males and four females with nevoid basal cell carcinoma syndrome (NBS) is presented. The patients were 14-54 years of age. Fourteen angular and 26 linear variables were measured and compared with control data. The main roentgencephalometric features were: proportionate increase of the size of the calvarium, protrusion of the frontal and parietal region, low position of the occipital region, increased interorbital distance, increased length of the mandible, mandibular retrognathia due to changes in shape and position of the mandible. The suggestion of a characteristic craniofacial morphology as a part of the syndrome was substantiated. Together with other skeletal aberrations the roentgencephalometric findings seemed to indicate that the syndrome is a dysostosis of generalized type.

Adolescent↗
PubMedDate not supplied

Hepatitis C virus antibodies in homosexual men and intravenous drug users in Denmark.

In order to evaluate the role of sexual transmission and parenteral transmission of hepatitis C virus (HCV) in homosexual men and intravenous drug users (IVDU) serum samples from 147 homosexual men and 126 IVDU were tested for anti-HCV. Anti-HCV was found in two (1.4%) of the homosexual men and in 123 (98%) of IVDU. The presence of anti-HCV could not be correlated to the presence of HBV markers or HIV-antibodies. HCV is widespread among Danish IVDU. Risk of sexual transmission seems low even though sexual contact is a much more prevalent risk factor than needle sharing.

Adult↗
PubMedDate not supplied

A comparison of an enzyme immunoassay and cell culture for detection of Chlamydia trachomatis in genito-urinary specimens.

Chlamydia trachomatis infection is easy to treat but laborious to diagnose by culture. An antigen-detecting enzyme immunoassay (EIA; Chlamydiazyme, Abbott Laboratories, North Chicago, IL), suitable for testing many samples, was compared with the conventional iodine-stained, one-passage culture. A total of 471 duplicate samples from 218 men (urethra) and 128 women (urethra and cervix) attending a sexually transmitted disease clinic were examined by both tests. The overall sensitivity, specificity, and predictive value of positive and negative results were 80.3%, 96.7%, 86.4%, and 95.0%, respectively. No difference between male and female patients was observed. A remarkable difference between sensitivities of female urethral (60.0%) and cervical (95.5%) samples was found. This difference is clearly important in cases of women with urethral infection only (19% in our study) and points to the need for further improvement of this EIA.

Bacteriological Techniques↗
PubMedDate not supplied

Anomalies of craniofacial skeleton and teeth in cleidocranial dysplasia.

Mutations involving the transcription factor CBFA1 cause cleidocranial dysplasia (CCD) in man. Recently, a mouse model of CCD has been generated (Cbfal +/-) [Komori et al., 1997], and disturbances of osteoclast differentiation have been documented. It has been shown that these animals exhibit hypoplastic clavicles and nasal bones, and retarded ossification of parietal, interparietal, and supraoccipital bones. Humans with CCD show all these features, including severely retarded ossification of the cranial base, strongly suggesting that both intramembranous ossification and endochondral ossification are affected. In addition, CCD patients have multiple supernumerary teeth and delayed tooth eruption. The present report presents 3D reconstructions of computerised tomography (CT) scans of the craniofacial region of a CCD boy examined at both 1 and 7 years of age. The anomalies in craniofacial skeleton and teeth are analysed and compared to the findings of our previous clinical studies and to the findings in the animal model. Based on the available information, we suggest that osteoblast, osteoclast, and dentinoclast differentiation may be disturbed in CCD.

Child↗