Distribution patterns of occlusal contact areas on natural posterior teeth - Evaluations of a cross-sectional population-based study with the Greifswald Digital Analyzing System (GEDAS)

AIM

The aim of our investigations is to optimize the anatomical basis for the design of a sufficient occlusal relationship, especially in view of the innovative technologies by analyzing the occlusal contact point patterns at cusp structures according to A-, B-, C- localization tooth by tooth on the individual occlusal surfaces in the posterior region in static habitual occlusal position.

MATERIALS AND METHODS

In 3300 subjects of the population-based Study of Health in Pomerania (SHIP 1) the interocclusal registration in habitual intercuspation using silicone registration was used and analyzed by using the special evaluation software Greifswald Digital Analyzing System (GEDAS II). Chi square test was used to investigate whether the distribution of contact areas differed in the group of premolars or molars - each considered separately for maxilla and mandible - on the basis of the probability of error p < 0.05.

RESULTS

In 709 subjects (446 male with a mean age of 48.9 ± 13.04 years; 283 female with a mean age of 52.4 ± 14.23 years) the antagonistic situation was specifically considered on natural posterior teeth without conservative or restorative-prosthetic interventions, i.e. without caries, fillings, crowns or other restorations. On the basis of these subjects, the silicone registrations were analyzed using GEDAS II. For the first and second upper molars, the ABC contact distribution was the most frequent: 20.4 % for the first and 15.3 % for the second molar. The second most frequent contact area for maxillary molars was area 0. The upper molars had contact areas only at the maxillary palatal cusp (B-/C-contacts). This contact relationship was most frequent in the maxillary premolar (18.1-18.6 %). In mandibular premolars, with the buccal cusps areas A and B were frequently involved (15.4-16.7 %). Mandibular molars showed a frequent contact pattern involving all A-, B-, C- and 0- contact areas (13.3-24.2 %). To capture the possible influence of the antagonistic dentition situation, the antagonistic situation was specifically considered and except for the mandibular premolars (p < 0.05) the contact distribution did not differ for molars and maxillary premolars regarding the dental status of the antagonistic teeth. Natural posterior teeth without occlusal contacts were observed from 20.0 % in the second lower molars to 9.7 % in the first upper molars.

CONCLUSION

Our results suggest a clinically relevant due to the fact, that this study is the first population-based epidemiological study to analyze the occlusal contact point patterns at cusp structures according to A-, B-, C- localization tooth by tooth on the individual occlusal surfaces in the posterior region in static habitual occlusal position in order to optimize the anatomical basis for the design of a sufficient occlusal relationship.

Coffee consumption and cardiovascular health in the general population

Background

Coffee, next to water the most widespread beverage, is attributed both harmful and protective characteristics concerning cardiovascular health. This study aimed to evaluate associations of coffee consumption with cardiac biomarkers, echocardiographic, and electrocardiographic parameters as well as major cardiovascular diseases.

Methods and results

We performed a cross-sectional analysis of 9,009 participants a large German population-based cohort study, enrolled between 2016 and 2018 median age 63 [IQR: 55; 69] years. Coffee consumption was classified into three groups: &lt;3 cups/day (low), 3–4 cups/day (moderate), &gt;4 cups/day (high). In linear regression analyses adjusted for age, sex, body mass index, diabetes, hypertension, and smoking, moderate and high coffee consumption were associated with LDL-cholesterol (β=2.08; 95% CI: 0.14, 4.03, p=0.036; β=5.69; 95% CI: 2.91, 8.47; p&lt;0.001). Moderate and high coffee consumption were negatively associated with systolic (β=−1.6; 95% CI: −2.66, −0.54; p=0.003; β=−2.63; 95% CI: −4.15, −1.12; p=0.001) and diastolic blood pressure (β=−0.8; 95% CI: −1.38, −0.22; p=0.007; β=1.28; 95% CI: −2.11, −0.45; p=0.002). Different levels of coffee consumption did neither correlate with any investigated electrocardiographic or echocardiographic parameter nor with prevalent major cardiovascular diseases, including prior myocardial infarction and heart failure.

Conclusions

In this cross-sectional analysis, moderate and high coffee consumption was positively associated with LDL-cholesterol and negatively associated with systolic and diastolic blood pressure. However, major cardiovascular diseases including heart failure and its diagnostic precursors were not associated with coffee consumption, connoting a neutral role of coffee in the context of cardiovascular health.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Deutsche Forschungsgemeinschaft [Grant Number TH1106/5-1; AA93/2-1]The Foundation Leducq [Grant Number 16 CVD 03]

Number and localization of occlusal contact areas on natural posterior teeth without dental findings - evaluations of the regional baseline study (SHIP-1) with the Greifswald Digital Analyzing System (GEDAS)

Sufficient occlusion is a basic prerequisite for the functional efficiency of the occlusal surfaces. Exactly where and in what number the occlusal contacts in the posterior region should be present for this purpose is controversial. The present study investigated the number and location of occlusal contacts on posterior teeth without dental findings, ie, without caries or restorative restorations such as fillings, crowns, etc. Such natural posterior teeth were present in 709 subjects (males (m) = 446: 48.9 ± 13.04 years, females (f) = 283: 52.4 ± 14.23 years) of a subject collective of 1223 subjects (m = 648, f = 575) of the regional baseline study 'Study of Health in Pomerania 1' (SHIP-1). Silicone bite registrations in habitual intercuspation (IP) were evaluated, whereby the test persons were asked to fix the bite block with biting force without biting firmly. The registrations were scanned with a document scanner in incident and transmitted light; a calibration strip was used to determine the transparency threshold of a layer thickness of 20 μm, below and equal to which the transparent zone was considered as a contact or contact area. The Greifswald Digital Analyzing System 2 (GEDAS 2) software was used to determine the number and location of occlusal contact areas tooth by tooth. To define the localization of the contacts, a cross with two concentric circles symmetric to the longitudinal fissure was superimposed on the occlusal surface; this resulted in four inner and four outer quadrants. Thus, the number of pixels in occlusal contact areas per inner and outer quadrant could be determined. The image resolution was 300 dpi. On average (median), the premolars had two occlusal contacts each, the posterior teeth had four to five, and tooth 46 had six contacts. The right and left teeth did not differ in the frequency of occlusal contacts in the Mann-Whitney U test for independent samples. In the maxillary premolars, frequent contact areas were primarily located mesially on the inner and outer slopes of the palatal cusp. In the maxillary molars, the palatal slope of the distopalatal cusp and the inner slopes of the mesiopalatal and distopalatal cusps were frequently affected. On the mandibular premolars, the inner slopes of the buccal cusps and the buccal slope of the distobuccal cusp were particularly frequently addressed; in teeth 35 and 45, the buccal slope of the mesiobuccal cusp was also somewhat more frequently addressed. Teeth 36 and 46 frequently had contact areas on the buccal slope of the distobuccal cusp as well as on the inner slopes of the distal cusps (distobuccal and distolingual), whereas teeth 37 and 47 tended to behave similarly. Epidemiologically, the focus of the frequent contact areas on the respective supporting cusps of the maxillary and mandibular posterior teeth and a distribution of contacts stabilizing the tooth in its position in the dental arch through the interlocking were confirmed. It makes sense to take this into account when designing occlusal surfaces in the posterior region.

Single mandibular implant study - chewing efficiency - 5-year results from a randomized clinical trial using two different implant loading protocols

PURPOSE

To investigate the chewing efficiency of edentulous patients wearing complete dentures, treated with a single implant in the mandible, placed underneath the existing mandibular dentures, using two different loading protocols (immediate loading or conventional loading), over an observation period of 5 years.

METHODS

One-hundred and fifty-eight (158) edentulous seniors aged 60-89 years received an implant in the midline of the lower jaw and were randomized either to the immediate loaded group A (n=81) or the conventional loaded group B (n=77). Chewing efficiency was obtained before treatment, one month after implant placement during the submerged healing phase (only group B) and 1, 4, 12, 24 and 60 months after implant loading.

RESULTS

After 5 years, chewing tests from 89 patients (45 in the immediate loading group and 44 in the conventional loading group) were available for every recall visit and thus statistically analyzed. The chewing efficiency increased over time in both groups. A significant increase was observed up to 4 months after loading (p≤0.05). Later, chewing efficiency further increased, but not significantly. Between the two loading protocols, chewing efficiency did not differ significantly (p>0.05) at any follow-up investigation.

CONCLUSION

A single mandibular implant placed underneath existing mandibular dentures improves chewing efficiency of edentulous patients significantly over an observation period of 5 years, irrespective of the loading protocol.

5-year randomized multicenter clinical trial on single dental implants placed in the midline of the edentulous mandible

OBJECTIVES

This multicenter randomized controlled clinical trial was conducted to investigate whether the loading protocol of single dental implants placed in the midline of edentulous mandibles will influence the implant survival or prosthetic maintenance.

MATERIALS AND METHODS

In total, 158 patients were randomly assigned either to the immediate loading group (n = 81) or to the delayed loading group (n = 77). All implants were loaded with an overdenture retained by a ball attachment.

RESULTS

After 5 years, 102 patients attended the follow-up investigation. Immediately loaded single implants in the midline of the edentulous mandible revealed a statistically significant lower survival rate than implants loaded conventionally over an observation period of 5 years. In the immediate loading group, 9 implants failed within the first three months of implant loading. No further implant loss was recorded for this group. Two implants failed in the delayed loading group, whereas one implant had to be removed during second-stage surgery and the second five years after implant loading. Non-inferiority of the survival rate of the midline implant of the immediate loading group, compared with the delayed loading group, could not be shown (p = .79, CI immediate loading: 74.9%; 100.0%, CI delayed loading: 73.0%; 100.0%). The observed difference in implant survival between the two treatment groups over time was statistically significant.

CONCLUSIONS

The results of the present study indicate that immediate loading of a single mandibular implant in the edentulous mandible should be considered only in exceptional cases.

Computerized occlusal analysis - innovative approaches for a practice-oriented procedure

A hands-on method for instrument-based occlusal analysis with digital technology is presented using a patient case example. The method is based on new software for digital occlusal analysis that includes a new measuring system for recording mandibular function (Jaw Motion Analyser Optic System/oJMA). With the new system, occlusal contact patterns in the real movement function of the mandible are captured and analyzed digitally with regard to occlusal interferences or a suitable therapeutic position of the mandible. For this purpose, scans of both jaws are brought together with the movement recordings by means of a special coupling tray and then visualized together as one complete image. Since the movement paths of the temporomandibular joints (TMJs) are also captured, the new system makes it possible to define a suitable therapeutic position specifically aimed at relieving the TMJs, and a therapeutic change in the jaw relation can be adjusted, for instance, by using an occlusal splint. Dedicated software modules provide a layer-by-layer analysis of the intercuspation relationship and the generation of 'envelopes' for occlusal gliding movements. This system is used to gain a deeper and more comprehensive understanding of the relationship between the structure and function of the occlusion. Interfaces to CAD software have also been established.

[Modern wound treatment-from best practice to innovation]

According to the Research Group for Primary Medical Care (PMV), approximately 890,000 people in Germany were suffering from a chronic wound in 2012. This corresponds to a prevalence of 1.1%. Ulcus cruris, diabetic ulcers and decubital ulcers are among the most frequent causes of chronic wounds (57-80%). The guarantee for successful wound care is based on a good understanding of the physiology of the wound healing process. A disorder of the phase-like course can lead to complications, delays or suspension of wound healing. There are many reasons for pathological wound healing including infections, oxygen deficiency and non-phase-adapted wound care. In addition to established wound products, innovative products such as dermal matrixes, cold plasma therapy and platelet-rich plasma represent promising therapeutic alternatives for non-healing chronic wounds.

Prodrugs of reverse fosmidomycin analogues

Fosmidomycin inhibits IspC (Dxr, 1-deoxy-d-xylulose 5-phosphate reductoisomerase), a key enzyme in nonmevalonate isoprenoid biosynthesis that is essential in Plasmodium falciparum. The drug has been used successfully to treat malaria patients in clinical studies, thus validating IspC as an antimalarial target. However, improvement of the drug's pharmacodynamics and pharmacokinetics is desirable. Here, we show that the conversion of the phosphonate moiety into acyloxymethyl and alkoxycarbonyloxymethyl groups can increase the in vitro activity against asexual blood stages of P. falciparum by more than 1 order of magnitude. We also synthesized double prodrugs by additional esterification of the hydroxamate moiety. Prodrugs with modified hydroxamate moieties are subject to bioactivation in vitro. All prodrugs demonstrated improved antiplasmodial in vitro activity. Selected prodrugs and parent compounds were also tested for their cytotoxicity toward HeLa cells and in vivo in a Plasmodium berghei malaria model as well as in the SCID mouse P. falciparum model.

Crystal structure of Brucella abortus deoxyxylulose-5-phosphate reductoisomerase-like (DRL) enzyme involved in isoprenoid biosynthesis

Most bacteria use the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for the synthesis of their essential isoprenoid precursors. The absence of the MEP pathway in humans makes it a promising new target for the development of much needed new and safe antimicrobial drugs. However, bacteria show a remarkable metabolic plasticity for isoprenoid production. For example, the NADPH-dependent production of MEP from 1-deoxy-D-xylulose 5-phosphate in the first committed step of the MEP pathway is catalyzed by 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) in most bacteria, whereas an unrelated DXR-like (DRL) protein was recently found to catalyze the same reaction in some organisms, including the emerging human and animal pathogens Bartonella and Brucella. Here, we report the x-ray crystal structures of the Brucella abortus DRL enzyme in its apo form and in complex with the broad-spectrum antibiotic fosmidomycin solved to 1.5 and 1.8 Å resolution, respectively. DRL is a dimer, with each polypeptide folding into three distinct domains starting with the NADPH-binding domain, in resemblance to the structure of bacterial DXR enzymes. Other than that, DRL and DXR show a low structural relationship, with a different disposition of the domains and a topologically unrelated C-terminal domain. In particular, the active site of DRL presents a unique arrangement, suggesting that the design of drugs that would selectively inhibit DRL-harboring pathogens without affecting beneficial or innocuous bacteria harboring DXR should be feasible. As a proof of concept, we identified two strong DXR inhibitors that have virtually no effect on DRL activity.

Differential effects of propionate or β-hydroxybutyrate on genes related to energy balance and insulin sensitivity in bovine white adipose tissue explants from a subcutaneous and a visceral depot

Ruminants rely on short-chain fatty acids (SCFA) as principal energy source. Herein, we compared the effects of propionate, β-hydroxybutyrate (BHB) and insulin on mRNA abundance of energy balance-related genes by short-term incubation (4 h) in bovine subcutaneous (SC) and retroperitoneal (RP) adipose tissue (AT) explants in vitro. Propionate either significantly (p < 0.05), or as a trend (p ≤ 0.1) affected mRNA abundance of genes such as adiponectin system in both depots in treated samples versus controls. Propionate increased adiponectin receptor 1 (AdipoR1) and AdipoR2 mRNA only in SC AT. β-hydroxybutyrate decreased mRNA abundance of adiponectin and AdipoR1 in SC AT as a trend. The mRNA abundance of free fatty acid receptor 2/3 (FFAR2/3) and other genes of interest (GOI) was increased during differentiation in bovine preadipocyte culture. The mRNA abundance of all the GOI remained unchanged after short-term insulin stimulation. In total, propionate, BHB or insulin during short-term treatment exert divergent effects on the mRNA abundance of GOI in both depots in vitro. Our results indicate that the bovine adiponectin system might be more sensitive to propionate than to BHB. We demonstrated the presence of FFAR2/3 mRNA not only in both AT depots but also in differentiating preadipocytes isolated from bovine SC AT. Therefore, we established that SCFA are able to exert insulin-independent effects on bovine adipose tissue, which might be independent from propionate uptake-related events.

What do our patients understand about their trial participation? Assessing patients' understanding of their informed consent consultation about randomised clinical trials

BACKGROUND

Ethically, informed consent regarding randomised controlled trials (RCTs) should be understandable to patients. The patients can then give free consent or decline to participate in a RCT. Little is known about what patients really understand in consultations about RCTs.

METHODS

Cancer patients who were asked to participate in a randomised trial were surveyed using a semi-standardised interview developed by the authors. The interview addresses understanding, satisfaction and needs of the patients. The sample included eight patients who participated in a trial and two who declined. The data were analysed on the basis of Mayring's qualitative analysis.

RESULTS

Patients' understanding of informed consent was less developed than anticipated, especially concerning key elements such as randomisation, content and procedure of RCTs. Analysing the result about satisfaction of the patients, most of the patients described their consultations as hectic and without advance notice. Health limitations due to cancer played a decisive role. However, most of the patients perceived their physician to be sympathetic. Analysing the needs of patients, they ask for a clear informed consent consultation with enough time and adequate advance notice.

CONCLUSION

This study fills an important empirical research gap of what is ethically demanded in an RCT consultation and what is really understood by patients. The qualitative approach enabled us to obtain new results about cancer patients' understanding of informed consent, to clarify patients' needs and to develop new ideas to optimise the informed consent.

Conformationally restrained aromatic analogues of fosmidomycin and FR900098

The synthesis and in-vitro antimalarial activity of conformationally restrained bis(pivaloyloxymethyl) ester analogues of the natural product fosmidomycin is presented. In contrast to alpha-aryl-substituted analogues, conformationally restrained aromatic analogues exhibit only moderate in-vitro antimalarial activity against the chloroquine-sensitive strain 3D7 of Plasmodium falciparum. The most active derivative displays an IC(50) value of 47 microM.

α-Phenylethyl Substituted Bis(pivaloyloxymethyl) Ester Analogues of Fosmidomycin and FR900098

α-Phenylethyl substituted bis(pivaloyloxymethyl) ester analogues of the natural products Fosmidomycin and FR900098 have been synthesized, and their in vitro antimalarial activity determined. The α-phenylethyl substituted Fosmidomycin analogue displays moderate in vitro antimalarial activity against the chloroquine-sensitive strain 3D7 of Plasmodium falciparum.

[Painful bruising syndrome]

A 54-year old anorectic patient with painful bruising syndrome (Gardner-Diamond syndrome) suffered from various gastrointestinal and psychologic complaints. The episodes of painful bruising could be provoked following intradermal injection of washed red blood cells within 96 h. The pathogenesis of this rare entity is more likely due to a psychiatric alteration rather than to the immunological mechanisms, as had been postulated two decades ago. Nevertheless, the Gardner-Diamond-syndrome should be included in the differential diagnosis of ecchymotic bleeding.

Self-administered topical 5% imiquimod for the treatment of common warts and molluscum contagiosum

BACKGROUND

Despite numerous therapeutic options the treatment of common warts and molluscum contagiosum remains unsatisfactory for both patients and physicians. Imiquimod, a novel topical immune response modifier, has been successfully used for the treatment of external anogenital warts.

OBJECTIVES

We aimed to evaluate the safety, tolerance and efficacy of imiquimod for the treatment of common cutaneous warts and mollusca that were resistant to previous therapeutic interventions.

METHODS

Imiquimod 5% cream was self-applied by the patients to the warts or mollusca once daily for 5 days per week and left in place overnight. Assessment for response and the occurrence of side-effects was performed every 4 weeks until clinical cure or up to a maximum of 16 weeks.

RESULTS

Twenty-eight of 50 (56%) patients with warts achieved a total clearance (n = 15; 30%) or a > 50% reduction in wart size (n = 13; 26%) after a mean treatment period of 9.2 weeks. Twelve of 15 (80%) patients with mollusca achieved a total clearance (n = 8; 53%) or a > 50% reduction in molluscum size (n = 4; 27%). There was no difference in response with regard to gender, human immunodeficiency virus serostatus or atopic predisposition.

CONCLUSIONS

Patient-applied 5% imiquimod cream holds promise as an effective treatment of common warts and mollusca in a difficult-to-treat patient population.

Up-regulated perforin expression of CD8+ blood lymphocytes in generalized non-anaphylactic drug eruptions and exacerbated psoriasis

Perforin expressed in CD8+ cytotoxic T cells is known to mediate the lysis of target cells carrying microbial as well as tumor-associated antigens, and to be involved in autoimmune and transplant reactions. The aim of the present investigation was to study the role of perforin- and CD8-expressing effector lymphocytes from peripheral blood in patients with generalized inflammatory skin diseases. Mononuclear cells were separated from peripheral venous blood and permeabilized by 0.1% saponin. The co-expression of cytoplasmatic perforin and cell membrane-residing CD8 was determined in lymphocytes by immuno-flow cytometry. Patients affected by generalized macular-papular drug eruptions (n = 14), drug-unrelated acute urticaria (n = 10) and drug-independently exacerbated psoriasis (n = 11, PASI scores ranging from 25 to 35), as well as control individuals not affected by any inflammatory skin disease (n = 10) were enrolled. Additionally, n = 5 patients with drug-induced Stevens-Johnson syndrome (SJS) were included. The average proportion of CD8+ peripheral lymphocytes co-expressing perforin in generalized drug eruptions (68.8+/-24.9%) and exacerbated psoriasis (67.2+/-17.1%) differed significantly from the controls (43.5+/-11.6%; p 0. 05), whereas no significant difference for acute urticaria (58.2+/-23.1%) could be measured. In each of the 5 SJS patients treated by high dose systemic steroids the parameter substantially declined during the first 7 days after admission from an average value of 81. 6% down to 33.0%. Thus, as compared to controls we observed an increased perforin+ proportion of CD8+ lymphocytes in generalized drug eruptions and in exacerbated psoriasis but not in acute urticaria. Therefore the parameter showed some specificity as a marker of distinct inflammatory skin disorders, and proved to be useful in monitoring the disease activity of SJS under anti-inflammatory medication. Furthermore, the findings point to a possible crucial role of CD8+ lymphocytes in the pathogenesis of psoriasis.

Colour coded duplex sonography in ischemic finger artery disease--a comparison with hand arteriography

BACKGROUND

A reliable non-invasive diagnostic procedure is desirable to exclude arterial pathology in patients with pain in their fingers.

PATIENTS AND METHODS

The results of colour coded duplex sonography (CCDS) in 450 finger arteries (45 hands/41 patients) were compared with findings obtained by intra-arterial digital subtraction arteriography (i.a.-DSA). The population consisted of symptomatic patients with a high risk for finger artery pathologies.

RESULTS

Arteriography of the hand documented finger artery occlusion in 35.6% of these patients. CCDS is capable of detecting pathological alterations in finger arteries with high accuracy and can differentiate them from regular arteries. In patients with several diseases of the finger arteries, the ultrasound diagnosis concurred with arteriography in 93.1% of patent arteries. In patients with occluded arteries the accuracy of CCDS was 86.3%.

CONCLUSION

When assessing diseases of finger arteries non-invasive CCDS should be used routinely before referring the patient to arteriography. The latter is only indicated when there is a need to image the whole arterial trunk of the upper extremity or the hand, or in case of equivocal results of CCDS.

Analysis of clonal CD8+ T cell expansions in normal individuals and patients with rheumatoid arthritis

In the course of studying the circulating TCR repertoire in humans, we noted several individuals with an increase in the percentage of CD8+ T cells expressing a particular V region. In some cases, these CD8 expansions were dramatic, occupying over 40% of the total CD8 repertoire. Using a panel of mAbs to different TCR V regions, we found that over 30% of healthy adults (&gt; 35 years of age) harbor an expansion that alters the peripheral blood CD8 TCR repertoire. A wide range of V regions were expressed by these expansions. Considering that the mAbs used cover only a portion of the V beta repertoire, the data suggest that over 70% of adults are likely to harbor such expansions. Junctional region sequencing showed that the CD8 subset expansions were clonal, and serial studies as long as 4 years showed that they persisted indefinitely. Expansions were not identified in the CD4 population. Discordant expression of one large V beta 6.7+ clone was found in one identical twin set, suggesting the possibility that an environmental exposure is involved in their generation and/or expansion. In one large family, we found five family members with a large CD8 subset expansion. Remarkably similar usage of J beta regions was noted, and two individuals demonstrated V beta 3-expressing clones with homologous CDR3 regions, differing by only one major substitution. The repertoire data from this family suggest that the T cell clones have arisen in response to a common Ag. Studies of patients with rheumatoid arthritis found a significantly increased frequency of circulating CD8 subset expansions that expressed a different V region repertoire compared with the healthy individuals studied. Overall, our results emphasize a frequent alteration in the human CD8 TCR repertoire, most likely related to an environmental exposure, in both healthy individuals and patients with rheumatoid arthritis. The presence of these expansions will be important to consider in any study of human TCR repertoire, and their implication for health and disease will be important to understand.

Analysis of clonal CD8+ T cell expansions in normal individuals and patients with rheumatoid arthritis

In the course of studying the circulating TCR repertoire in humans, we noted several individuals with an increase in the percentage of CD8+ T cells expressing a particular V region. In some cases, these CD8 expansions were dramatic, occupying over 40% of the total CD8 repertoire. Using a panel of mAbs to different TCR V regions, we found that over 30% of healthy adults (> 35 years of age) harbor an expansion that alters the peripheral blood CD8 TCR repertoire. A wide range of V regions were expressed by these expansions. Considering that the mAbs used cover only a portion of the V beta repertoire, the data suggest that over 70% of adults are likely to harbor such expansions. Junctional region sequencing showed that the CD8 subset expansions were clonal, and serial studies as long as 4 years showed that they persisted indefinitely. Expansions were not identified in the CD4 population. Discordant expression of one large V beta 6.7+ clone was found in one identical twin set, suggesting the possibility that an environmental exposure is involved in their generation and/or expansion. In one large family, we found five family members with a large CD8 subset expansion. Remarkably similar usage of J beta regions was noted, and two individuals demonstrated V beta 3-expressing clones with homologous CDR3 regions, differing by only one major substitution. The repertoire data from this family suggest that the T cell clones have arisen in response to a common Ag. Studies of patients with rheumatoid arthritis found a significantly increased frequency of circulating CD8 subset expansions that expressed a different V region repertoire compared with the healthy individuals studied. Overall, our results emphasize a frequent alteration in the human CD8 TCR repertoire, most likely related to an environmental exposure, in both healthy individuals and patients with rheumatoid arthritis. The presence of these expansions will be important to consider in any study of human TCR repertoire, and their implication for health and disease will be important to understand.

Voluntary testing for human immunodeficiency virus (HIV) in a prison population with a high prevalence of HIV

This study evaluated voluntary testing for human immunodeficiency virus (HIV) in a prison population with a high HIV seroprevalence. Data on demographic variables and participation in voluntary testing were linked to a blinded HIV serosurvey of consecutive Maryland prison entrants (April-July 1991). Among 2,842 entrants, HIV seroprevalence was 8.5% (men, 7.9%; women, 15.3%). Voluntary testing was accepted by 47% of the entrants, and it identified 34% of the HIV-seropositive inmates detected by serosurvey. Refusers of testing were more likely to test HIV-seropositive than were accepters (adjusted odds ratio (OR) = 1.84, 95% confidence interval (CI) 1.58-2.16). Refusers and accepters of testing had similar risk factors for HIV infection, chiefly current syphilis infection (adjusted OR = 5.96, 95% CI 3.15-10.27) and prior injected drug use (adjusted OR = 4.26, 95% CI 3.15-5.76). Among 100 entrants asked why they refused testing, primary reasons given included low risk of HIV, fear of testing HIV-seropositive, and lack of interest. Voluntary testing appears only moderately successful in identifying HIV-seropositive inmates in a high-seroprevalence prison population. However, the alternative, mandatory HIV testing of prisoners, can be construed as discriminatory and unethical when similar screening is not imposed on the population at large. Data presented here suggest strategies to improve acceptance of voluntary testing, especially by high risk inmates.

[Color-coded duplex ultrasound of lower leg arteries--image reliability with reference to Fontaine stages]

We examined the accuracy of colour flow detection of lower limb arteries in relation to Fontaine's criteria of obstructed peripheral circulation. Assessments were conducted in relation to stages I and II as well as to stages III and IV and compared to the corresponding i. a.-DSA: On comparing the total of all ultrasound results in stages (I-IV) with those of arteriography (92 calf arteries) we found a sensitivity between 80 and 90% and a specificity between 90 and 97%. Results did not differ from these values in the subgroups Fontaine II-IV. Especially in the stages III/IV in comparison to stage II we could not find any disadvantages of colour coded vessel imaging. With sufficient reliability we succeeded in demonstrating calf arteries in endangiitis (Bürger's disease) and in diabetics with mediasclerosis.