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Biomedical subjects

R Berg

Publications and source records attributed to R Berg.

At least 19 recordsLinked to original sources
PubMed1999

Retrospective evaluation of the outcome of orthodontic treatment in adults.

The aim of this study was the retrospective evaluation of the outcome of orthodontic treatment in consecutively treated adult patients. Of 147 adult patients, it was possible to evaluate the records of 88 patients (57 female, 31 male) before (T1) and after treatment (T2), and of 20 of these patients 3.3 years on average after completion of the retention phase (T3). During treatment planning, a nearly "ideal" result was considered attainable (ideal group) for 46 patients, and a "compromise" result (compromise group) was seen as realistic for 42. The assessment was made using the PAR (Peer Assessment Rating) index and the Aesthetic Component (AC) and Dental Health Components (DHC) of the IOTN (Index of Orthodontic Treatment Need). Average length of treatment in the ideal group was 2.4 years, i.e. nearly twice as long as in the compromise group. The PAR score was reduced by an average of 56% (T2); the reduction in the ideal group was 73%, and in the compromise group 37%. Among the 20 patients for whom at least 6 months had elapsed since completion of the retention phase, a statistically significant relapse between T2 and T3 was observed. The evaluation of overjet and overbite and, in the ideal group, of the midline and maxillary front teeth were primarily responsible for the worsening of the PAR scores between T2 and T3. According to the AC, 53 patients (60%) had moderate to definite treatment needs at the beginning of treatment. Following completion of active treatment, 69 patients (78%) no longer demonstrated treatment indications for aesthetic or psychosocial reasons. Based on the DHC, 88% of the patients were in definite or moderate need of treatment (T1); in contrast, treatment was no longer indicated in 84% at T2. In general, a marked improvement of the examined morphological parameters was observed.

Adult↗
PubMed1998

Analysis of leukocytes recruited to the pancreas by diabetogenic T cell clones.

To investigate host leukocytes recruited to the pancreas by diabetogenic T cells, we administered islet-specific CD4(+) T cell clones to 2-week-old nonobese diabetic (NOD) mice and examined the resulting pancreatic infiltrate by flow cytometry. Two different Vbeta4(+)CD4(+) T cell clones, BDC 2.5 and BDC 6.9, were found to recruit a heterogeneous T cell population as determined by staining with a panel of anti-TCR Vbeta monoclonal antibodies. The majority of the diabetes-initiating, Vbeta4(+) T cell clones migrated to the spleen whereas only 5-8% of the T cell population infiltrating the pancreas was Vbeta4(+). Anti-IL-2 receptor staining indicated that fewer than 10% of the total population of infiltrating lymphocytes within the pancreas were in a highly activated state. We have further found that normal splenic T cells from the NOD mouse proliferate poorly to IL-2 in vitro, yet secrete IFN-gamma in response to IL-2 stimulation. These results suggest that the recruited host T cells in our disease transfer system are not directly pathogenic but, rather, are responding to the small numbers of inflammatory T cell clones by providing cytokines that facilitate the disease process.

Animals↗
PubMed1998

A novel extracellular domain variant of the human integrin alpha 7 subunit generated by alternative intron splicing.

The integrin alpha 7 beta 1 laminin receptor, which is expressed on replicating myoblasts, and upregulated during myogenic differentiation, is involved in cell adhesion and communication between muscle cells and the extracellular matrix. It is a major cell-surface substrate in skeletal muscle cells for the cell-surface, argininespecific, ADP-ribosyltransferase. Both the extracellular and cytoplasmic domains of the mouse alpha 7 subunit undergo alternative splicing during development, generating differentially expressed variants with presumably unique ligand-binding and signalling properties. Here human cDNA clones isolated from a fetal heart lambda gt10 cDNA library encoded the complete sequence of the alpha 7 subunit and hybridised to a single major 4.4 kb alpha 7 subunit transcript abundantly expressed in human skeletal muscle, moderately expressed in heart, and weakly expressed in most other tissues. One clone out of four contained a novel 225-nucleotide in-frame deletion corresponding to 75 amino acids in the C-terminal region of the extracellular domain. The variant, whose expression appears to be tissue-specific, is created by alternative splicing at sites flanking an intron in the alpha 7 gene. A related mouse form was identified in P19 embryonal carcinoma cells. Deletion of the spliced region, which either contains or is in very close proximity to the major ADP-ribosylation site of the alpha 7 subunit, may serve to modulate the effects of ADP-ribosylation, or alternatively molecular associations, and receptor-ligand affinity.

Alternative Splicing↗
PubMed1998

A wonderful smile.

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Esthetics, Dental↗
PubMed1998

Feedback.

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Feedback↗
PubMed1998

Identification of multiple forms of 180-kDa ribosome receptor in human cells.

Herein, we describe the analysis and mapping of cDNA clones encoding variant forms of the human homolog of the canine 180-kDa ribosome receptor (p180). One form, similar to the chicken ES/130 homolog, possesses a large uninterrupted C-terminal region composed predominantly of heptad repeats predicted to form an alpha-helical double-stranded coiled-coil rod. Other forms contain in addition a 10-amino acid consensus motif, NQGKKAEGAQ, repeated up to 54 times in tandem close to the N-terminus. Such repeats in canine p180 represent a ribosome-binding domain. The cDNA hybridized to a major 6-kb transcript in all tissues examined, where very high expression was observed in tissues that carry out a high level of secretion such as pancreas, liver, and placenta. The ES130/p180 gene was mapped to chromosome 20p12, and a potential pseudogene appears to reside on chromosome 7. In summary, the data suggest that p180 exists in humans in different forms because of complete removal of tandem repeats, or partial intraexonic splicing, creating different repeat lengths with potentially novel ribosome-binding characteristics.

Alternative Splicing↗
PubMed1998

Dental caries prevalence and treatment need in Chiriqui Province, Panama.

A pathfinder pilot survey was conducted in rural Chiriqui Province, Panama, using standard WHO methodology, in order to estimate dental caries prevalence and treatment need. Examinations for caries and treatment need were performed by six trained, experienced examiners. From a convenience sample of 2,597 subjects, a stratified cluster sample was constructed using index ages 12 and 15 years and age groups 35-44 and 65-74 years. The results showed a mean Decayed, Missing and Filled Teeth index (DMFT) of 4.08 for 12 year olds, 6.40 for 15 year olds, 13.20 for the 35-44 age group, and 18.88 for the 65-74 age group (P < 0.001). No statistically significant differences by gender were found. These findings rank rural Panama with Mexico and Haiti when compared to the results of other Central American community studies. The percentage of caries free 12 year olds was 6.8 per cent. Of the total sample, 74.7 per cent of individuals would require one or multiple surface restorations and 47.9 per cent would require at least one extraction. Restorative need was greatest in the 15 year olds. The severity of dental caries in this sample was moderately severe and the treatment need extraordinarily high.

Adolescent↗
PubMed1998

Knowledge and attitudes of Arizona high-school coaches regarding oral-facial injuries and mouthguard use among athletes.

The authors assessed high-school athletic coaches' perceptions about oral-facial injuries and mouthguard use in sports that do not mandate mouthguard use. About 72 percent of the coaches said that their athletes sustained oral-facial injuries, 28 percent that some athletes used mouthguards regularly, 48 percent that athletes had sustained injuries and did not use mouthguards regularly, and 31 percent said they would not encourage mouthguard use. Advocacy for mouthguard use should focus on coaches, coaches' associations and rule-making organizations.

Adolescent↗
PubMed1997

xid affects events leading to B cell cycle entry.

X-linked agammaglobulinemia patients and X-linked immunodeficient (xid) mice possess mutations in the Bruton's tyrosine kinase (Btk kinase) gene and display defects in B cell development and activation by sIg cross-linking. Btk is an early activation kinase in sIg-cross-linked B cells. xid does not ablate Btk protein kinase activity, and immediate signal transduction events, such as tyrosine phosphorylation, occur in sIg-activated xid B cells. These cells do not subsequently progress into cell division and have a high rate of apoptosis, which has been shown to correlate with an absence of sIg-mediated induction of the bcl-xL protein. To establish the point where Btk activity is critical for progression beyond immediate signaling, we examined early and late events in sIg-cross-linked xid B cells. Induction of proto-oncogenes and nuclear factors occurred normally in xid cells. However, induction of cyclins and increased GAPDH mRNA was not observed in xid cells. Degradation of the cyclin inhibitor p27Kip1 occurred normally in xid cells. After 24 h of culture with anti-mu, the remaining live, nonapoptotic xid cells were enlarged, viable, and primed for subsequent stimulation by LPS. Our data suggest that the Btk kinase is not essential for several G1 events and that the failure of sIg-activated xid B cells to enter cell cycle correlates with a defect of cyclin induction. Moreover, these data suggest that Btk is important not only for immediate events following B cell activation and control of apoptosis but also for subsequent events leading to cyclin activation.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed1997

Pharmacokinetic studies on 5-aminolevulinic acid-induced protoporphyrin IX accumulation in tumours and normal tissues.

Laser-induced fluorescence (LIF) for in vivo point monitoring and fluorescence microscopy incorporating a CCD camera were used to study the fluorescence distribution of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in tumours. Fluorescence in a chemically-induced adenocarcinoma in the liver of rats and in an aggressive basal cell carcinoma in a patient were studied after intravenous injection of ALA at a dose of 30 mg/kg body weight. The LIF technique demonstrated slightly more ALA-induced PpIX fluorescence in the tumour than in the surrounding normal liver and abdominal muscle of rats. The visible parts of the human basal cell carcinoma exhibited strong ALA-induced fluorescence, while this fluorescence was much weaker in the necrotic areas of the tumour and in the surrounding normal skin.

Adenocarcinoma↗
PubMed1997

Laser-induced fluorescence studies of normal and malignant tumour tissue of rat following intravenous injection of delta-amino levulinic acid.

BACKGROUND AND OBJECTIVE: Laser-induced fluorescence was studied in normal and tumour tissue of rat after intravenous injection of delta-amino levulinic acid (ALA). The aim of the study was to investigate the protoporphyrin IX accumulation in different tissue types in rat after systemically administered ALA. STUDY DESIGN/MATERIAL AND METHODS: A malignant rat tumour and normal tissue from 13 different organs were investigated in eight rats. The rats were injected with two different ALA doses, 30 and 90 mg/kg b.w., and the investigations were performed at 10, 30 and 240 min after the injection. The fluorescence was recorded utilising an optical fibre based fluorosensor at 405 nm excitation. RESULTS: Fluorescence spectra were recorded in the 400-750 nm wavelength region including the dual-peaked PpIX fluorescence at about 635 and 705 nm, and the tissue autofluorescence peaking at about 500 nm. The maximum tumour build-up of PpIX was achieved already in less than 1 hr after ALA injection. The fluorescence demarcation between tumour and surrounding tissue was a factor of 7-8:1 after 30 min and decreased for longer retention times. The accumulation in 13 different organs was investigated and a particularly high PpIX build-up was found in stomach and intestine. CONCLUSIONS: Fluorescence detection following i.v. injection of ALA provides attractive diagnostics for the experimental tumour used, indicating clinical usefulness.

Aminolevulinic Acid↗
PubMed1997

Time-resolved white light transillumination for optical imaging.

PURPOSE: To describe a new breast-imaging method with the potential of multi-spectral optical transillumination based on a time-resolved technique. MATERIAL AND METHODS: A breast phantom was irradiated with ultra-short laser pulses of white light generated by self-phase modulation of an incident high-power laser pulse in water. Time-resolved detection of the transmitted light was performed. Contrast resolution was studied using different absorbers located inside the breast phantom. RESULTS AND CONCLUSION: The results showed that simultaneous, multi-spectral transillumination is possible. The technique can also be used for measurements of optical properties in tissue.

Breast↗
PubMed1997

Morphometry of the small intestine in pigs with ileo-rectal anastomosis.

Ileo-rectal anastomosis (IRA), which is frequently used to measure prececal digestibility in pigs, could induce some disturbances of the normal absorptive function. Our aim was to investigate the effects of different IRA surgical procedures on the main histologic characteristics of the small intestine in pigs. The 4 different IRA procedures compared to intact pigs (INT) were the following: either end to end (EE) or end to side (ES) with or without preservation of the ileocecal valve (EEV, EE, ESV, ES respectively). At 147 d after surgery, samples of the wall of the duodenum, jejunum and ileum were taken under anesthesia and histometric examinations were performed on HE- and PAS-colored sections to estimate changes mainly of mucosa and muscle layers. The values recorded for villus length, crypt depth, and whole thickness of the mucosa suggested that the EE procedures disturb the small intestine less than the ES models. A new parameter, called epithelial quotient and calculated as [(villus length/crypt depth)/mitotic index], was proposed to improve the comparisons. According to this quotient, EE procedures did not significantly affect the mucosa of the whole small intestine. An increased density of goblet cells was recorded in all operated pigs along the small intestine, but mainly in the ileum after EE-IRA. The lymphatic follicle area was reduced. These findings, which were in agreement with a reduced mitotic index in the ileum of EE-pigs, indicated a decreased effect of noxious factors on the small intestinal mucosa in IRA-pigs, especially after the EE-IRA procedure. Some atrophic or hypertrophic effects on the muscle layers were related to the absence or preservation of the ileo-cecal valve. Finally it was concluded that i) there was no major disturbance after IRA, and ii) the end to end procedure was most beneficial for the structural integrity of the small intestine.

Anastomosis, Surgical↗
PubMed1997

Physiologic changes in the elderly.

A variety of age-related changes in the oral cavity and throughout the aging body can affect dental care and treatment plans. Some of these changes may be unavoidable features of senescence. Others, previously thought to be part of "normal aging," may be modifiable with lifestyle choices or may represent subclinical pathological processes. The ability to compensate for losses in system capacity varies among individuals and may result in functional changes ranging from substantial to unmeasurable. An appreciation of the intricacy of these relationships, and coordinated treatment with the primary care physician, can enhance the dental care of the aged patient.

Aged↗