Ulnar variance and subchondral bone mineralization patterns in the distal articular surface of the radius

PURPOSE: Based on biomechanical experiments in specimens it is accepted widely that ulnar length determines loading of distal articular surface of the radius with ulna-minus variance increasing and ulna-plus variance decreasing the loading of the lunate compartment. Nevertheless a direct assessment of the actual loading conditions in the living is currently impossible. The aim of the present study is therefore to evaluate subchondral bone mineralization patterns to provide further information about the role of ulnar length in load transmission through the radiocarpal joint. METHODS: Twelve wrists of healthy subjects with an average age of 33 years and an average congenital ulna-minus wrist of -2.8 mm (range, -4 to -1 mm) were examined by means of computed tomography-osteoabsorptiometry. A further 5 wrists in healthy subjects with an average age of 52 years and an average congenital ulna-plus variance of +3.0 mm (range, +2 to +4 mm) were examined with the same technique. Seventeen wrist joints of 9 healthy subjects with ulna-zero variance were examined in the control group. RESULTS: The results show a mainly lunate mineralization pattern in subjects with ulna-minus wrists in 75% of the cases, which is more frequent than in subjects with ulna-zero wrists. The results in ulna-plus variance show a mainly scaphoid mineralization pattern in 100% of cases. The differences in mineralization patterns are statistically significant. CONCLUSIONS: We conclude from these morphologic results in living subjects that ulnar length determines the peak mineralization patterns of the distal articular surface of the radius with a relatively lesser loading of the lunate fossa in ulna-plus variance and a relatively higher loading history in most cases of ulna-minus variance. The hypothesis, however, that ulna-minus variance is always a sign of a relatively higher loading history of the lunate fossa cannot be supported.     

Gingival cysts in the adult

BACKGROUND: Gingival cysts in the adult are unusual cysts of odontogenic origin with less than 100 reported, including this series. Even rarer are cases of multiple gingival cysts. This paper reports the second largest retrospective study of biopsy cases of adult gingival cysts with a spectrum of their features and another case of multiple gingival cysts. METHODS: The files of a biopsy service were reviewed for the most recent 10-year period. Data collected included location, age, gender, clinical features, clinical diagnosis, and histologic features. These were compared to previous reports. There was also a case report of multiple cysts. RESULTS: Twenty-two adult gingival cysts were retrieved, 2 of which were multiple. They are uncommon cysts of odontogenic origin, noted primarily in the fifth and sixth decades with only a slight predilection for females. They occur more in the mandible on the labial attached gingiva of the anterior teeth. Histology shows a very thin, uninflamed wall lined by a very thin squamoid or cuboidal epithelium. Multiple cysts are very rare. CONCLUSIONS: Gingival cysts in the adult are uncommon cysts that are diagnosed at the clinical level about 50% of the time, with others being confused with a mucocele. They may be bluish due to the fluid and may cause pressure resorption of the labial bone, yielding a radiolucency sometimes confused with a lateral periodontal cyst. Treatment consists of an excisional biopsy.     

Suppression of tumorigenicity and anchorage-independent growth of BK virus-transformed mouse cells by human chromosome 11.

Viral transformation models may be useful for detecting and mapping human tumor suppressor genes. BK virus (BKV), a human papovavirus, readily transforms rodent cells but is unable to transform human cells, suggesting that oncosuppressive functions expressed in human cells control BKV oncogenic activity. We have transferred human chromosome 11 to BKV-transformed mouse cells. All of the cell clones were suppressed in the tumorigenic phenotype and anchorage-independent growth, except one clone which was nontumorigenic but maintained the ability to grow in soft agar. Cytogenetic analysis and DNA hybridization with chromosome 11-specific probes showed that all the reverted hybrids had an intact human chromosome 11, except the clone growing in semisolid medium which had lost the short arm. The results suggest that a gene located on 11p controls anchorage independence, whereas a gene on 11q controls the tumorigenicity of BKV-transformed cells. BKV T-antigen was expressed in all the hybrid clones at the same level as in the parental cell line, indicating that the putative human tumor suppressor gene(s) do not inhibit expression of the viral oncogene and must operate by another mechanism in inducing reversion of the oncogenic phenotype. Since BKV-transformed mouse cells are highly susceptible to retrovirus infection, this model can be used for searching and cloning tumor suppressor gene(s) by retrovirus-mediated "insertional mutagenesis".     

2-Amino-3-aroyl-4,5-alkylthiophenes: agonist allosteric enhancers at human A(1) adenosine receptors.

2-Amino-3-benzoylthiophenes are allosteric enhancers (AE) of agonist activity at the A(1) adenosine receptor. The present report describes syntheses and assays of the AE activity at the human A(1)AR (hA(1)AR) of a panel of compounds consisting of nine 2-amino-3-aroylthiophenes (3a-i), eight 2-amino-3-benzoyl-4,5-dimethylthiophenes (12a-h), three 3-aroyl-2-carboxy-4,5-dimethylthiophenes (15a-c), 10 2-amino-3-benzoyl-5,6-dihydro-4H-cyclopenta[b]thiophenes (17a-j), 14 2-amino-3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophenes (18a-n), and 15 2-amino-3-benzoyl-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophenes (19a-o). An in vitro assay employing the A(1)AR agonist [(125)I]ABA and membranes from CHO-K1 cells stably expressing the hA(1)AR measured, as an index of AE activity, the ability of a candidate AE to stabilize the agonist-A(1)AR-G protein ternary complex. Compounds 3a-i had little or no AE activity, and compounds 12a-h had only modest activity, evidence that AE activity depended absolutely on the presence of at least a methyl group at C-4 and C-5. Compounds 17a-c lacked AE activity, suggesting the 2-amino group is essential. Polymethylene bridges linked thiophene C-4 and C-5 of compounds 17a-j, 18a-n, and 19a-o. AE activity increased with the size of the -(CH(2))(n)()- bridge, n = 3 < n = 4 < n = 5. The 3-carbethoxy substituents of 17a, 18a, and 19a did not support AE activity, but a 3-aroyl group did. Bulky (or hydrophobic) substituents at the meta and para positions of the 3-benzoyl group and also 3-naphthoyl groups greatly enhanced activity. Thus, the hA(1)AR contains an allosteric binding site able to accommodate 3-aroyl substituents that are bulky and/or hydrophobic but not necessarily planar. A second region in the allosteric binding site interacts constructively with alkyl substituents at thiophene C-4 and/or C-5.     

Reflex vasoconstriction following dental injections

Three case reports of transient facial blanching or vasoconstriction that followed administration of dental anesthetic are presented. A review of vasomotor cutaneous control is given, along with a proposal to explain this phenomenon.     

Recurrent bacterial meningitis occurring five years after closed head injury and caused by an intranasal post-traumatic meningo-encephalocele

A case of atypical presentation of a post-traumatic intranasal meningo-encephalocele is described in a patient with a history of recurrent bacterial meningitis occurring 5 years after closed head injury. The usefulness of the CT and MRI findings in diagnostic evaluation of this lesion is emphasized.