Bizarre parosteal osteochondromatous proliferation (Nora's Lesion) of the mandible. a rare bony lesion.

Bizarre parosteal osteochondromatous proliferation (BPOP) also eponymically called "Nora's lesion", is a rare benign reactive bone lesion first reported in 1983. BPOP occurs classically on the bones of the hands and feet and long bones. This lesion can easily be confused, both clinically and microscopically, with other benign and malignant lesions of bone, including osteochondroma, parosteal osteosarcoma, myositis ossificans and reactive periostitis. BPOP has been reported to have a high rate of recurrence. Only 3 cases of BPOP of the head and neck have been reported in the literature, of which one involved the maxilla. We present a rare case of BPOP involving the mandible in a 10 year old African American male. Microscopically, a fibro-cartilaginous cap giving rise to a proliferation of variably mineralized osteophytic finger-like projections of bone was seen. Multiple trabeculae of "blue bone" were noted as well as numerous atypical appearing chondrocytes. The lesion recurred within 4 months following the initial excision but has not recurred to date after the second local excision. To the best of our knowledge, this is the first report of BPOP arising in the mandible. In addition, we discuss the clinical and microscopic features, differential diagnosis, and prognosis of this rare entity. We present a case of BPOP of the mandible and believe this is the first report of such a case in the mandible.

The effect of molecular orientation and acetylene-enhanced crosslinking on the wear of UHMWPE in total artificial joints.

This paper investigates the benefits of combining roll-drawing and acetylene-enhanced crosslinking to alter the mechanical properties of the ultra high molecular weight polyethylene (UHMWPE) used in total hip and knee replacements, with the aim of improving its resistance to wear. UHMWPE was processed via crosslinking, roll-drawing and a combination of crosslinking and roll-drawing and subjected to gel content analysis, tensile tests, X-ray diffraction and wear tests using different types of motion and smooth and rough counterfaces. Purely roll-drawn materials with length and width draw ratios of lambda l x lambda w = 1.3 x 1.0 and lambda1 x lambdaw = 1.6 x 0.9 respectively, were found to have lower wear factors in a unidirectional motion test with a rough counterface when compared to the virgin material. The crosslinked roll-drawn material, with length and width draw ratios of lambda1 x lambdaw = 1.6 x 0.9, was seen to possess five crosslinks per initial number average molecule. This crosslinked and roll-drawn material showed 5.5 times less wear than the virgin material in a multidirectional motion test with a smooth counterface and 1.4 times more wear than the virgin material in a unidirectional motion test with a rough counterface. Hence this study supports previous work by the authors that acetylene-enhanced crosslinked materials may show benefits for a total hip replacement, but only where the femoral head remains smooth. The improvements in wear with the roll-drawn material in unidirectional tests were smaller, but may prove to have some benefits in the knee.

Parental bonding and anxiety: differences between African American and European American college students.

Empirical evidence suggests that early home environments characterized by low care and high overprotection are positively associated with the adult expression of anxiety. While available evidence supports this position for European Americans, there has been no examination of the relationship between perceived parental rearing practices and anxiety among African Americans despite the theoretical assertion that African American parenting environments may be characterized as somewhat more overprotective than European Americans. This study investigated the relationship between maternal rearing patterns and trait and state measures of anxiety and depression among a sample of 59 African American and 55 European American college students. Results indicated that both groups reported similar levels of anxiety, depression, perceived care, and perceived overprotection. European Americans exhibited the typical pattern of a negative relationship between anxiety, depression, and care and a positive relationship between anxiety and overprotection. African Americans evidenced a similar negative relationship between anxiety, depression, and care, but no relationship between anxiety, depression, and overprotection. Furthermore, specific aspects of ethnic identity (i.e., ethnic achievement, ethnic behaviors) were found to be negatively associated with measures of trait anxiety among African Americans but not European Americans.

Behavioral choice treatment promotes continuing weight loss: preliminary results of a cognitive-behavioral decision-based treatment for obesity.

Twenty-four obese women were randomly assigned to 1 of 2 group treatments: behavioral choice treatment (BCT) or traditional behavioral treatment (TBT). BCT uses decision theory to promote moderate behavior change that can be comfortably, and therefore permanently, maintained. Groups completed a moderate-intensity walking program and obtained feedback from computerized eating dairies. The TBT group evidenced greater weight loss at posttreatment. However, the TBT group also evidenced a trend to regain weight, whereas the BCT group continued a slow weight loss during follow-up. Exercise followed a similar pattern. Both groups decreased in restraint and increased in self-esteem.

Affirmative action and other special consideration admissions at the University of California, Davis, School of Medicine.

CONTEXT: The use of race as a criterion for admission to medical schools and other professional schools has become increasingly controversial. This study documents the experience of students at one medical school, admitted through a special admissions process that included race as one consideration. OBJECTIVE: To examine the medical school, postgraduate training, and career experiences of students admitted by a special consideration admission program that included traditional affirmative action admissions. DESIGN: Twenty-year, retrospective, matched-cohort study. SETTING: A public medical school. STUDY POPULATION: All affirmative action and other special consideration admissions between 1968 and 1987 (20 years). MAIN OUTCOME MEASURES: Academic progress, national board examination scores, graduation, residency evaluations, and practice characteristics. RESULTS: During the study period, 20% of students were special consideration admissions (range, 10%-45% per year). Of special consideration admissions, 53.5% were minority students, while 19% of regular admissions were minority students. When only underrepresented minority groups are analyzed, 42.7% of special consideration admissions and 4.0% of regular admissions were minorities. Of special consideration admissions, 94% graduated vs 97% of regular admissions. Regular admission students were more likely to receive honors or an A grade on core basic and clinical science courses. There was no difference in failure rates of core courses. Regular admission students had higher scores on Parts I and II of the National Board of Medical Examiners examination, and special consideration students were more likely to repeat the examination to receive a passing grade. Following graduation, the experience of the special consideration admission students was very similar to that of regular admission students. There was no difference in completion of residency training or evaluation of performance by residency directors. Both populations selected primary care disciplines at the same rate. The practice characteristics of the 2 populations were remarkably similar. CONCLUSIONS: Criteria other than undergraduate grade point average and Medical College Admission Test scores can be used in predicting success in medical school. An admissions process that allows for ethnicity and other special characteristics to be used heavily in admission decisions yields powerful effects on the diversity of the student population and shows no evidence of diluting the quality of the graduates.

Neonatal circumcision techniques.

Neonatal circumcision is most commonly performed using one of three techniques--the Mogen clamp, the Gomco clamp or the Plastibell device. With all three techniques, careful selection and preparation of patients is essential. Informed consent must be obtained from parents or guardians, based on an objective understanding of the medical and social implications of circumcision, including potential complications from the procedure. Measures for creating an aseptic field, anesthesia and positioning of the infant do not vary with the technique selected. Both the Mogen and Gomco clamps protect the glans while producing crush injury to the prepuce, which is then surgically removed. The Plastibell device induces necrotic tissue, which is sloughed off, along with the plastic shield, within a week or so. Although complications from neonatal circumcision are rare, hemorrhage, local infection, sepsis, meatal ulceration and poor cosmetic results have been reported.

Cystourethropexy to correct refractory urinary incontinence due to urethral sphincter mechanism incompetence. Preliminary results in ten bitches.

Cystourethropexy was performed in 10 bitches with refractory urinary incontinence due to urethral sphincter mechanism incompetence. All animals had an abnormally shaped vesicourethral junction. The bladder neck was located in the pelvic canal in nine dogs (pelvic bladder). Surgery alone restored urinary continence in two cases and markedly improved incontinence in two cases. Surgery combined with medical therapy (phenylpropanolamine, 1.5 mg/kg orally once or twice a day, using a sustained-action preparation) restored urinary continence in four cases and markedly improved continence in one case. Surgery, with medical therapy, was completely ineffective in one case. No major complications were encountered in any dogs. In four cases, histopathologic evaluation of the dorsal bladder wall and neck revealed the presence of a single, perinuclear, clear vacuole in the cytoplasm of smooth muscle fibers. Electron microscopic examination showed that the vacuoles represented a dilatation of normal membrane organelles. Such abnormalities have the potential to alter the smooth muscle motility. This study indicates that cystourethropexy alone restored urinary continence only temporarily in the majority of the patients. The significance and frequency of the histopathologic findings requires further investigation.

Differential in vitro inhibition of feline enteric coronavirus and feline infectious peritonitis virus by actinomycin D.

The growth of feline enteric coronavirus strain 79-1683 in whole feline embryo cells was inhibited by the presence of 1 microgram/ml of actinomycin D in the culture fluid. No virus-specific mRNAs could be detected in such cultures and yields of infectious virus were depressed by > 99%. By contrast, the antigenically related feline infectious peritonitis virus strain 79-1146 was unaffected by the presence of actinomycin D, indicating a fundamental difference between the two feline coronavirus strains in their requirements for host-encoded function(s).

Semen quality in varicocele patients is characterized by tapered sperm cells.

We used a retrospective case-control study design to compare sperm morphology in 50 varicocele patients and 50 patients with idiopathic infertility. Cases and controls were matched for the percentage of motile sperm and total sperm number per ejaculate. Varicocele patients had significantly more tapered sperm (36% +/- 3% versus 15% +/- 2%) and significantly fewer oval sperm (41% +/- 3% versus 47% +/- 2%). There was no significant difference between cases and controls in any other morphological type.

The relationship of circulating antisperm antibodies to sperm surface antibodies in infertile men.

The correlation between the amount and location of antisperm antibody binding to the sperm surface and the level measured in the serum has not been previously reported. Hence, the value and limitations of screening blood sera from men with suspected immunologic infertility are not currently known. In this study 70 paired sera and semen samples were assayed by the immunobead test (IBT). A screening protocol for blood sera was constructed to be 100% sensitive for detecting semen specimens with 20% or more of sperm binding IgG or IgA immunobeads. The specificity of this screening protocol was determined to be 79%. Serum IgA was not a good predictor of IgA on the sperm surface. The true positive predictive rate for antisperm antibodies on the sperm surface using circulating antisperm antibodies as a screening assay was estimated to be as low as 35%. There was little correlation between the site of immunobead binding following passive antibody transfer from patients' sera to donor sperm and the site of naturally occurring antibodies on the patients' sperm surface. Although direct assessment of antibodies on the sperm surface is preferred, these data suggest that serum IgG alone can be used as a sensitive screening assay for antisperm antibodies in men. A positive screen dictates that a direct assay on semen should be performed.

Behaviour of a replicating mitochondrial DNA sequence from Aspergillus amstelodami in Saccharomyces cerevisiae and Aspergillus nidulans.

An amplified sequence of mitochondrial DNA from a ragged (rgd) mutant of Aspergillus amstelodami has been shown to exist in multimeric circular form, suggesting that it is excised from the genome and can exist independently of it. This sequence has replicative (ARS) activity in Saccharomyces cerevisiae, and a subfragment responsible for this activity has been identified and sequenced. A homologous sequence from Aspergillus nidulans mtDNA also has ARS activity in S. cerevisiae. Both A. amstelodami and A. nidulans ARS elements have been incorporated into the integrative transformation vector pDJB1 and the derived vectors used to transform A. nidulans. Inclusion of the A. nidulans ARS element enhanced the transformation frequency 5-fold relative to pDJB1. No increase in transformation frequency was evident with the ARS element from A. amstelodami. The stability of transformants was variable but in comparison to pDJB1, ARS-containing plasmids were mitotically unstable in A. nidulans. Although plasmid DNAs could be rescued in Escherichia coli from undigested transformant DNA, no freely replicating plasmids were detected by Southern hybridisation.

Prospective surveillance of semen quality in the workplace.

We performed a prospective surveillance of semen quality among workers in the plant where 1,2-dibromo-3-chloropropane was first recognized as an occupational cause of impaired semen quality and of infertility. All male employees of the Agricultural Chemical Division were required to participate. Ninety-seven workers (92% participation) provided 258 semen samples over the 4 years of the program. Most samples were analyzed at the plant with a mini-laboratory designed for the study. Motility and shape measures were made objectively. Sixty-six subjects (68%) were non-azoospermic. Generalized multiple regression showed no significant predictors for any response, with the exception of the motility measures, which were reduced with longer times between ejaculation and assay. Between- and within-person standard deviations and correlations were calculated. Comparison of this population with fertile artificial insemination donors (16 men, 498 ejaculates) revealed generally higher ejaculate-to-ejaculate standard deviations in the worker samples. This is probably due to less well controlled conditions of sperm collection in the workplace setting. For cross-sectional studies, one ejaculate per worker is recommended as sufficient; for estimating an individual worker's mean, even three ejaculates may not provide enough precision.

Antisperm antibodies bind with different patterns to sperm of different men.

Immunologic infertility is an important area of current clinical research. The immunobead test is a laboratory method that identifies the classes of antisperm antibodies and their binding sites on the sperm surface. In this study we have investigated the variability in the pattern of antibody binding to spermatozoa after passive transfer from blood serum. Serum from a single donor containing antisperm antibodies of the IgG class was used in all experiments. The spermatozoa from 27 semen donors were found to differ significantly in the degree and location of immunobead binding after exposure to this serum. There was substantial day-to-day variability in the results for individual semen donors and the overall variability in test results was significantly greater when a number of semen donors was used rather than a single donor. These data suggest that details of antisperm antibody binding after passive transfer from body fluids may depend on the sperm donor. The design of research studies involving antibody transfer must take this source of variability into account.

Morphometric analysis of spermatozoa in the assessment of human male fertility.

A videomicrographic system was developed for measurement of morphometric parameters of human spermatozoa. Contours of the images of spermatozoa on a video monitor are digitized by manually tracing them with the cursor of an electromagnetic digitizer integrated to a microcomputer. The accuracy and precision of the methodology were evaluated. A comparison of human sperm heads in shallow wet preparations and in dried, stained preparations indicated that the latter were smaller in length, width, projected area, and circumference, but that the ratio length/width was not different. An analysis was made of 457 ejaculates from 16 fertile donors. The variation between ejaculates within donors was similar in magnitude to the variation between donors. A study was performed comparing seminal sperm morphometry in single specimens from 30 fertile and 30 infertile men. The sperm head length/width ratio was the parameter that differed the most between these two groups. Moreover, it was the per-ejaculate variability of this parameter, rather than the central tendency, that maximized the difference.

Measurement of human testicular consistency by tonometry.

A tonometer was used for objective assessment of testicular consistency in a group of 83 men. Testicular measurements in three dimensions were also obtained using calipers. The testicular tonometry value was found to be significantly correlated with the clinical impression of testicular consistency and with testicular size. The testicular tonometry value for the right testicle was significantly larger than the tonometry value for the left testicle in all men except those with azoospermia. The difference in tonometry values between the right and left testicles was most significant in the group of men with left varicocele. The men with varicoceles also had left testicles which were significantly smaller than the paired right testicle in two of three dimensions. In the group with varicocele there was a significant positive correlation between the tonometry value and sperm concentration in the semen. In men with no history of varicocele there was a significant positive correlation between the tonometry value and the percentage of oval sperm.

Human sperm function in the ejaculate following vasectomy.

Semen specimens were obtained for analysis from nine men immediately before vasectomy and 3 days following the vasectomy procedure. After vasectomy there was a significant decrease in seminal sperm concentration, percentage of sperm motility, and mean swimming speed. In seven of nine cases the spermatozoa did not survive overnight incubation in capacitation media, and in no case was penetration of zonafree hamster oocytes observed 3 days after vasectomy.

SAMP lyase and AMP deaminase activity in rat parenchymal and kupffer cells in hepatocarcinogenesis.

SAMP lyase and AMP deaminase were determined in parenchymal and kupffer cells of rats fed either basal or carcinogen-enriched diets. Results were calculated on a U/mg protein and U/cell basis. Data indicated that although deaminase increased 1 1/2 to 2-fold in parenchymal cells on a U/mg protein and U/cell basis from rats fed carcinogen-enriched diets there was a greater increase in U/mg protein. In contrast, little to no increase was seen in kupffer cells. SAMP lyase, however, depicted a smaller increase in parenchymal cells of carcinogen-enriched diet fed rats, but a 4- to 5-fold elevation in kupffer cells regardless of whether the data were expressed in U/mg protein or U/cell. These data indicate that increased activity of AMP deaminase may be a result of resistance to degradation in parenchymal cells, whereas SAMP lyase elevations in kupffer cells may reflect an increase in enzyme concentration.