Biomedical subjects
Publications and source records attributed to P Watkins.
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A study was conducted to evaluate the impact of practice modifications on treatment time for patients in a private orthodontic office. Two patient groups were studied, consisting of Class I nonextraction, adult dentitions treated by one of the authors. One group (28 cases) was treated with the standard Begg technique and conventional motivation, hygiene, and finishing practices. The other (25 cases) was treated with the Tip-Edge appliance along with specific modifications to motivation, hygiene and finishing techniques. The average treatment time for the Tip-Edge group was 12.80 months versus 20.89 months for the Begg group. The use of motivational techniques and a specific mission and philosophy within a private orthodontic practice can help reduce total treatment time. The Tip-Edge appliance may reduce treatment time in Class I nonextraction therapy.
In November and December 1992, an outbreak of parvovirus B19 infection occurred among patients and staff on an adult mixed surgical ward at a large hospital in London. Three patients and 15 staff members were serologically confirmed as acute cases. The attack rate among susceptible members of staff was 47%. In those infected, arthralgia (80%) and rash (67%) were the most common symptoms. Of six susceptible in-patients on the ward, three became infected. One of the in-patients who had carcinoma of the mouth was viraemic for more than 10 days with marrow suppression resulting in the postponement of chemotherapy until intravenous immunoglobulin was given and he was no longer viraemic. Control measures taken included closure of the ward to new admissions, transfer of only immune staff to the ward, and restriction of the ward nursing staff to working only on that ward. Although no specific exposure was conclusively identified as a risk factor, there was a suggestion of an increased risk of acquiring parvovirus B19 infection among those staff who did not adopt strict hand washing procedures after each physical contact with a patient (RR = 2.33; P = 0.07). Knowledge of parvovirus B19 among interviewed health care workers was poor: only 42% reported knowing about parvovirus B19 and only 38% could name a patient category at risk of a severe outcome following infection. This is the first report of a nosocomial outbreak affecting an adult ward and of possible transmission of parvovirus B19 infection from staff to in-patients. Hospital control of infection teams should include parvovirus B19 in their outbreak containment plans.
OBJECTIVE: To validate a narrow band method for the detection of transient evoked otoacoustic emissions (TEOAEs) in neonates. DESIGN: A method for the assessment of TEOAEs was implemented. The method was based upon assessing the estimated signal to noise ratio of a narrow band of TEOAEs from 1.6 kHz to 2.8 kHz. This method was tested against a commercially available broad band TEOAE test, the Otodynamics ILO88 in quickscreen mode. Trials were performed on 162 ears from a group of normal neonates aged from 3 to 6 wk. RESULTS: The sensitivity of the method was 100% and its specificity was 92%, against the ILO88 test when looking for the absence of TEOAEs. When the ILO88 test was limited in time so that the number of undetected TEOAEs from both tests were similar, the narrow band test took 40% less time than the ILO88 test. CONCLUSIONS: The narrow band TEOAE detection method, as implemented here, did not miss any neonate ears without TEOAEs. However, the narrow band test did not detect TEOAEs in 8% of the group in which TEOAEs were detected by the ILO88. With a two-stage screening test and a 0.6% incidence of sensorineural hearing loss, it is predicted that 1.9% of neonates with TEOAEs would be misclassified, by the narrow band test. (It is predicted that the ILO88 quickscreen test would misclassify 1.1% under the same conditions.) The test is faster and easier to perform than the broad band ILO88 test.
The association of Epstein-Barr virus (EBV) with a growing number of human malignancies underlines the importance of efforts aimed at preventing the infection with this potential carcinogen and of establishing animal models for human virus-associated tumors. Cottontop tamarins have been used in EBV vaccine studies because virus infection regularly induces lymphomas similar to those seen in human immunocompromised individuals. In recent years, several vaccines based on the gp340/220 envelope protein of EBV have been developed and shown to prevent the development of EBV-associated lymphomas in this model. Using in situ hybridization and immunohistology, we have characterized EBV infection in one nonimmunized and three immunized animals after challenge with a standard tumorigenic dose of EBV. In the nonimmunized animal, EBV-infected lymphoid cells were detected in numerous tissues showing no obvious lymphoma infiltration. Surprisingly, variable numbers of virus-carrying cells were also found in all three immunized animals that were protected against the development of virus-associated lymphoma. This observation demonstrates that vaccination does not induce sterilizing immunity against EBV infection in this model. Double labeling suggested a B cell phenotype of the majority of these cells. EBV infection of nonlymphoid cells was not observed. Analysis of viral gene expression in immunized animals suggested a restricted form of virus latency different from that seen in EBV-driven lymphomas in nonimmunized cottontop tamarins. These results raise the possibility that immunized cottontop tamarins protected against the development of EBV-driven lymphoma or animals exposed to a sublymphomagenic dose of virus may serve as a model for EBV infection in humans.
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A 96-bp synthetic oligonucleotide corresponding to an amino acid sequence near the N-terminus of erythroid beta-spectrin was used to screen a human genomic library, and two overlapping recombinants were isolated. DNA sequence analysis established that the genomic fragment encoded beta-fodrin, the nonerythroid form of beta-spectrin, by correlation to a known amino acid sequence of human brain beta-fodrin. The genomic DNA contained regions that cross-hybridized with an erythroid beta-spectrin cDNA probe, and the DNA sequence of these regions revealed a high degree of identity with that of erythroid beta-spectrin and a similar exon/intron organization. A single-copy DNA fragment of the beta-fodrin genomic clone was used to screen a lymphoid cell cDNA library and two recombinants were isolated. The composite DNA sequence of these various genomic and cDNA clones encoded almost all of the first twelve 106 amino acid repeat segments of beta-fodrin that shared 58% identity and 75.5% similarity with the amino acid sequence of beta-spectrin and 66% identity with the nucleotide sequence of beta-spectrin cDNA. The chromosomal localization of the gene was determined to be chromosome 2 by hybridization of a single-copy probe derived from the cloned genomic DNA to DNA of a panel of somatic hybrid cell lines, and in situ hybridization localized the gene to band 2p21. beta-Fodrin was assigned the gene symbol SPTBN1.
Two versions of cognitive-behavioral therapy (CBT), one with religious content (RCT) and one with standard protocol (NRCT), were used to treat 19-20 religious patients each. Fifty-nine religious patients who met the Research Diagnostic Criteria for nonpsychotic, nonbipolar depression were treated in 18-20 1-hr sessions over 3 months. Religious and nonreligious therapists were used in each CBT group. Pastoral counseling (PCT) treatment-as-usual and waiting-list control (WLC) conditions each contained 10-11 patients. RCT and PCT patients reported significantly lower posttreatment depression and adjustment scores than did either the NRCT or the WLC condition. The CBT difference was due largely to superior performance of the nonreligious therapists (with dissimilar values to the patients) in the RCT over the NRCT condition. Improvement in the three treatment conditions was equal at 3-month and 2-year follow-ups and greater than posttreatment WLC improvement levels.
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At surgery, the results of preoperative radiographic evaluation are used in conjunction with surgical stents to determine the ideal site and angulation of implants. However, it would be desirable to be able to plan the optimal implant location before the actual surgical appointment. This paper presents a technique in which barium-coated stents or dentures are used in conjunction with computer-assisted tomography to locate important anatomic landmarks, such as the inferior alveolar nerve, and anomalies of the underlying bone, such as deficiencies in ridge height, preoperatively. This allows more accurate determination of optimal implant placement.
Germ-free rats excreted considerably smaller amounts of the monoamine oxidase-inhibiting compound isatin than the substantially larger output by conventional animals of the same strain, although concentrations in brain and other tissues were similar in the two groups. Thus, isatin is likely to be elaborated both endogenously in rat tissues and "exogenously" by flora inhabiting the lumen of the alimentary tract.
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A sensitive and specific enzyme-linked immunoassay for antibodies to the human immunodeficiency virus type 1 (HIV-1) nef gene product, p27, has been developed using recombinant Escherichia coli-derived protein from the LAV-1-Bru sequence. Of 92 HIV-1 infected hemophiliacs, 72 (78%) produced anti-nef antibodies in this assay; the early appearance of anti-nef prior to full seroconversion was a rare event in this population, occurring in only one subject (approximately 1%). Anti-nef antibodies were not detected in any of 500 sera from 98 repeatedly HIV seronegative subjects who had been exposed to sexually transmitted modes of HIV infection (45 subjects) or through blood products (53 subjects). There was no significant association of titer or anti-nef antibody with protection from disease in HIV infection (p = 0.1). Although the nef protein is relatively immunogenic in natural infection, this study cannot confirm the previously reported high prevalence of anti-nef antibodies prior to seroconversion, nor the finding of anti-nef antibodies in HIV seronegative but exposed subjects.
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We have demonstrated the assignments of two gene loci (COLIA2, MET) and two noncoding DNA markers (D7S13, D7S8) to owl monkey chromosome 14 (K-VI) by hybridizing DNA probes from the cystic fibrosis (CF) region of human chromosome 7q21-32 to panels of rodent-owl monkey somatic cell hybrids. The assignments are substantiated by in situ chromosome hybridization of markers COLIA2, MET, and D7S13 to the distal long arm of chromosome 14 (K-VI). These results support genomic conservation of the human CF region, at least in the higher primates.
Procedural variations affecting the reliability of the Mini-Mental State (MMS) were investigated in three studies using three different populations. Consistent results were obtained from studies of neurologically normal, at-risk, and impaired individuals which show that the test item involving serial subtractions is significantly more difficult than the alternative item involving backward spelling. MMS users are cautioned against assuming the comparability of scores across individuals, and should specify which attention and concentration task they employ in their evaluations.
Rodent-human somatic cell hybrids have been constructed which contain fragments of human chromosome 21 as their only human material. This was done by irradiating rodent-human somatic cell hybrids containing a complete chromosome 21 to fragment the genome and then rescuing human GAR synthetase and various amounts of flanking chromosome 21 DNA by fusing with GAR synthetase-deficient hamster cells and selecting for growth in purine-free medium. Four irradiation-reduction hybrids were produced by this method and contain the distal, proximal, and central portions of the long arm of human chromosome 21, all centered about GAR synthetase. These irradiation-reduction hybrids were used as a panel to regionally map single-copy and individual copies of repetitive sequences. Using these hybrids along with another independently constructed hybrid, the GAR synthetase gene was mapped distal to SOD-1 and proximal to CP21G1(D21S60). Of special interest is the regional mapping of the gene for the amyloid beta-protein distal to pPW236B(D21S11) and proximal to SOD-1.