Genotoxicity of acetaldehyde- and crotonaldehyde-induced 1,N2-propanodeoxyguanosine DNA adducts in human cells.

Reaction of crotonaldehyde or two molecules of acetaldehyde with DNA generates 3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxy-6-methylpyrimido[1,2-a]purine-10(3H)one (2, Scheme 1), which occurs in (6R, 8R) and (6S, 8S) configurations (Fig. 1). These diastereomers were site-specifically incorporated into oligonucleotides, which were then inserted into a double-stranded DNA vector for genotoxicity studies. Modified DNA was introduced into human xeroderma pigmentosum A (XPA) cells to allow replication. Analysis of progeny plasmid revealed that these DNA adducts inhibit DNA synthesis to similar degrees. (6S, 8S)-2 miscodes more frequently than (6R, 8R)-2: 10% versus 5%. For both adducts, major miscoding events were G-->T transversions, but G-->A transitions were also observed at a comparable level for (6R, 8R)-2. G-->C transversions were the second most common events for (6S, 8S)-2. Comparison of these results with those of other 1,N2-propanodeoxyguanosine (PdG) adducts, which were evaluated by the same system, indicates that (i) their synthesis inhibiting potencies are stronger than that of the unsubstituted analog, 3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purine-10(3H)one (1, Scheme 1), but weaker than that of 3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-6-hydroxypyrimido[1,2-a]purine-10(3H)one (3, Scheme 1); (ii) both isomers of 2 are more miscoding than 1; (iii) the miscoding potency of (6S, 8S)-2 is comparable to those of 3 and a model PdG 4 lacking a hydroxyl and a methyl group (Fig. 1). Therefore, considering the fact that 2 are formed endogenously as well as exogenously, they may play a significant role in aging and cancer in humans.

Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with bilateral disk displacement without reduction.

The purpose of this study was to evaluate the effect of bilateral disk displacement without reduction (BDDN) on the skeletal and dental pattern of affected individuals. There were 59 symptomatic female patients and 46 asymptomatic normal female volunteers. All study participants had bilateral high-resolution magnetic resonance imaging scans in the sagittal (closed and open) and coronal (closed) planes to evaluate the temporomandibular joints. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base, and dental characteristics of the two groups. A smaller cranial base length (Ba-Na) was found in the symptomatic group. The facial plane angle was smaller, and the angle of convexity was larger because of the retropositioned mandible. The lower denture base was also retruded as shown by the smaller SNB angle. The BDDN group exhibited a larger overjet. The mandibular plane angle was steeper, the Y-axis was more vertical (S-Gn to FH), the posterior ramal height (Ar-Go) was shorter, and the angle between the mandibular and the palatal plane (PP to MP angle) was increased in the symptomatic group. No significant dental differences were found. This study showed that alterations in skeletal morphology might be associated with BDDN. This study suggests that subjects with BDDN may manifest altered craniofacial morphology. The clinician should be aware of that possibility, especially for the growing patients and the surgical candidates.

Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with unilateral disk displacement with reduction.

The purpose of this study was to evaluate the effect of unilateral disk displacement with reduction (UDDR) on the skeletal and dental pattern of affected individuals. There were 18 symptomatic female patients and 46 asymptomatic normal female volunteers. All study participants had bilateral high-resolution magnetic resonance scans in the sagittal (closed and open) and coronal (closed) planes to evaluate the temporomandibular joints. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base, and dental characteristics of the two groups. Analysis of variance was used to compare the symptomatic with the control subjects. A few skeletal differences were found. There was an overall reduction in length of the anterior (S-Na) and posterior (S-Ba) cranial base measurements in the UDDR group. The cranial base angle was also increased. Both upper and lower dentures bases were retropositioned. The posterior ramal height (Ar-Go) was shorter in the symptomatic group. This study showed that alterations in skeletal morphology may be associated with UDDR. The mechanisms that produce DD or the mechanisms that cause this skeletal alteration are yet to be clarified. This study suggests that subjects with UDDR may manifest altered craniofacial morphology. The clinician should be aware of this possibility, especially for growing patients.

What litigators need to know about HIPAA.

HIPAA's Privacy Regulations impose a number of new requirements on Covered Entities concerning disclosure of an individual's personal health information. This Article briefly outlines the primary function of HIPAA's general nondisclosure rule and discusses the exceptions under which HIPAA permits disclosure in the course of litigation or government investigations.

Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with normal temporomandibular joints.

The purpose of this study was to evaluate the skeletal and dental pattern of symptomatic individuals (SN) with normal temporomandibular joints (TMJs). There were 42 symptomatic female patients with bilaterally normal TMJs and 46 asymptomatic normal female volunteers (AV). All study participants had bilateral high-resolution magnetic resonance scans in the sagittal (closed and open) and coronal (closed) planes to evaluate the TMJs. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base, and dental characteristics of the two groups. ANOVA was used to compare the symptomatic subjects with the control subjects. There were no significant differences between the two groups besides the lower incisor being more retruded in the asymptomatic group. This study showed that there are no alterations in skeletal morphology in SN individuals compared with AV.

Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with unilateral disk displacement without reduction.

The purpose of this study was to evaluate the effect of unilateral disk displacement without reduction (UDDN) on the skeletal and dental pattern of affected individuals. There were 12 symptomatic female patients and 46 asymptomatic normal female volunteers. All study participants had bilateral high-resolution magnetic resonance scans in the sagittal (closed and open) and coronal (closed) planes to evaluate the temporomandibular joints. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base, and dental characteristics of the two groups. ANOVA was used to compare the symptomatic subjects with the control subjects. A few skeletal differences were found. There was an overall reduction in length of the anterior (S-Na) and total (S-Ba) cranial base measurements in the UDDN group. The mandibular plane angle was steeper and the posterior ramal height (Ar-Go) was shorter in the symptomatic group. The only dental difference found was a relative infraeruption of the lower first molar. This study suggests that subjects with UDDN may manifest altered craniofacial morphology. Although the cephalometric measurements used did not account for any asymmetry, previous studies have shown that UDD may cause mandibular asymmetry. Presence of asymmetry and altered craniofacial morphology should alert the clinician especially while orthodontically treating children and surgical patients.

Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with bilateral degenerative joint disease.

The purpose of this study was to evaluate the effect of bilateral degenerative joint disease (BDJD) on the skeletal and dental patterns of affected individuals. There were 29 symptomatic female patients and 46 asymptomatic normal female volunteers. All study participants had bilateral high-resolution magnetic resonance scans in the sagittal (closed and open) and coronal (closed) planes to evaluate the temporomandibular joints. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base and dental characteristics of the two groups. Analysis of variance was used to compare symptomatic subjects with control subjects. There was an overall retrusion of the maxilla and mandible with a clockwise mandibular rotation. The upper and lower denture bases were retruded. The upper incisor was more protruded, whereas the lower incisor was more retroclined in the symptomatic group. The overjet was also increased. This study suggests that subjects with BDJD may manifest altered craniofacial morphology. Clinicians should be aware of this possibility, especially for patients who are growing children and orthognathic surgery candidates.

Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with bilateral disk displacement with reduction.

The purpose of this study was to evaluate the effect of bilateral disk displacement with reduction (BDDR) on the skeletal and dental pattern of affected individuals. There were 42 symptomatic female patients and 46 asymptomatic normal female volunteers. All study participants had bilateral high-resolution magnetic resonance scans in the sagittal (closed and open) and coronal (closed) planes for evaluation of the temporomandibular joints. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base, and dental characteristics of the two groups. Analysis of variance was used to compare the symptomatic subjects with the control subjects. The length of both the anterior (S-Na) and posterior (S-Ba) cranial base was smaller in the BDDR group. SNA and SNB angles were also smaller in the symptomatic group. There were also significant differences in the denture pattern. The interincisal angle was larger and the upper incisor was more retroclined in the BDDR group. This study showed that alterations in skeletal morphology may be associated with disk displacement (DD). The mechanisms by which DD is produced or the mechanisms that cause that skeletal alteration are yet to be clarified. This study suggests that subjects with BDDR may manifest altered craniofacial morphology. The clinician should be aware of this possibility especially for the growing patients and the orthognathic surgery candidates.