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K Chapin

Publications and source records attributed to K Chapin.

At least 19 recordsLinked to original sources
PubMed2001

Receptors for the carboxyl-terminal region of pth(1-84) are highly expressed in osteocytic cells.

PTH is a potent systemic regulator of cellular differentiation and function in bone. It acts upon cells of the osteoblastic lineage via the G protein-coupled type-1 PTH/PTH-related peptide receptor (PTH1R). Carboxyl fragments of intact PTH(1-84) (C-PTH fragments) are cosecreted with it by the parathyroid glands in a calcium-dependent manner and also are generated via proteolysis of the hormone in peripheral tissues. Receptors that recognize C-PTH fragments (CPTHRs) have been described previously in osteoblastic and chondrocytic cells. To directly study CPTHRs in bone cells, we isolated clonal, conditionally transformed cell lines from fetal calvarial bone of mice that are homozygous for targeted ablation of the PTH1R gene and transgenically express a temperature-sensitive mutant SV40 T antigen. Cells with the highest specific binding of the CPTHR radioligand (125)I-[Tyr(34)]hPTH(19-84) exhibited a stellate, dendritic appearance suggestive of an osteocytic phenotype and expressed 6- to 10-fold more CPTHR sites/cell than did osteoblastic cells previously isolated from the same bones. In these osteocytic (OC) cells, expression of mRNAs for CD44, connexin 43, and osteocalcin was high, whereas that for alkaline phosphatase and cbfa-1/osf-2 was negligible. The CPTHR radioligand was displaced completely by hPTH(1-84), hPTH(19-84) and hPTH(24-84) (IC(50)s = 20-50 nM) and by hPTH(39-84) (IC(50) = 500 nM) but only minimally (24%) by 10,000 nM hPTH(1-34). CPTHR binding was down-regulated dose dependently by hPTH(1-84), an effect mimicked by ionomycin and active phorbol ester. Human PTH(1-84) and hPTH(39-84) altered connexin 43 expression and increased apoptosis in OC cells. Apoptosis induced by PTH(1-84) was blocked by the caspase inhibitor DEVD. We conclude that osteocytes, the most abundant cells in bone, may be principal target cells for unique actions of intact PTH(1-84) and circulating PTH C-fragments that are mediated by CPTHRs.

Animals↗
PubMed2000

Deficient mineralization of intramembranous bone in vitamin D-24-hydroxylase-ablated mice is due to elevated 1,25-dihydroxyvitamin D and not to the absence of 24,25-dihydroxyvitamin D.

The 25-hydroxyvitamin D-24-hydroxylase enzyme (24-OHase) is responsible for the catabolic breakdown of 1,25-dihydroxyvitamin D [1,25(OH)2D], the active form of vitamin D. The 24-OHase enzyme can also act on the 25-hydroxyvitamin D substrate to generate 24,25-dihydroxyvitamin D, a metabolite whose physiological importance remains unclear. We report that mice with a targeted inactivating mutation of the 24-OHase gene had impaired 1,25(OH)2D catabolism. Surprisingly, complete absence of 24-OHase activity during development leads to impaired intramembranous bone mineralization. This phenotype was rescued by crossing the 24-OHase mutant mice to mice harboring a targeted mutation in the vitamin D receptor gene, confirming that the elevated 1,25(OH)2D levels, acting through the vitamin D receptor, were responsible for the observed accumulation of osteoid. Our results confirm the physiological importance of the 24-OHase enzyme for maintaining vitamin D homeostasis, and they reveal that 24,25-dihydroxyvitamin D is a dispensable metabolite during bone development.

24,25-Dihydroxyvitamin D 3↗
PubMed1999

Is Music Therapy an Effective Intervention for Dementia?A Meta-Analytic Review of Literature.

A recent qualitative review of literature in the area of music/ music therapy and dementias published since 1985 suggested that music/music therapy is an effective intervention for maintaining and improving active involvement, social, emotional and cognitive skills, and for decreasing behavioral problems of individuals with dementias (Brotons, Koger, & Pickett-Cooper, 1997). The present analysis sought to update and quantify this relationship, and investigate the extent to which methodological variables influenced treatment effectiveness. Twenty-one empirical studies, with a total of 336 subjects suffering from symptoms of dementia, were included in the meta-analysis. Overall, the effect of music/music therapy was found to be highly significant. A homogeneity analysis determined that the effect sizes were not consistent across studies; thus, a series of moderating variable analyses were conducted. We were unable to determine the source of variability between studies by analyzing type of therapeutic intervention (active or passive), music (live or taped), therapist's training (trained music therapist vs. other professional), dependent variable (behavioral, cognitive, or social), or length of treatment. Although the published literature demonstrates that music/music therapy is an effective method overall for treating symptoms of dementia, systematic variation of treatment protocols is necessary to identify the underlying mechanisms and delineate the most effective techniques.

Journal Article↗
PubMed1999

Comparison of the PACE 2 assay, two amplification assays, and Clearview EIA for detection of Chlamydia trachomatis in female endocervical and urine specimens.

Screening for sexually transmitted diseases (STDs) in a greater proportion of sexually active patients has become an accepted protocol by most health care providers. The purpose of this study was to compare the current test methods for detection of Chlamydia trachomatis used at the University of South Alabama, the PACE 2 assay (Gen-Probe) and the Clearview EIA (Wampole Laboratories), with two amplification technologies, the AMP CT (Gen-Probe) and LCx (Abbott) assays. In addition, a number of demographic parameters were ascertained by asking questions at the time of examination as well as for health care provider concerns and preferences. One urine and four endocervical swab specimens were collected in random order from 787 female patients attending one of four obstetrics-gynecology clinics. Eighty-seven percent of patients had no STD-related symptoms. Patients were considered positive for C. trachomatis if three or more assays (swab and/or urine) were positive. Abbott and Gen-Probe confirmed discrepant results by alternate amplified assays. A total of 66 true-positive specimens were detected by use of the combination of endocervical swabs and urine specimens. After discrepant analysis, sensitivities for endocervical swab specimens for the EIA and the PACE 2, LCx, and AMP CT assays were 50, 81, 97, and 100%, respectively. Sensitivities for the LCx and AMP CT assays with urine specimens were 98 and 81%, respectively. The prevalence of C. trachomatis was 8.4%, as determined by amplification technology. Overall, the amplification technologies were the most sensitive methods with either swab (AMP CT assay) or urine (LCx assay) specimens. The PACE 2 assay offered the advantage of a simpler and less expensive assay with acceptable sensitivity. The clearview CT EIA, while yielding a rapid in-office result, had unacceptably low sensitivity. The wide variation in performance with amplification assays with urine specimens as reported in both this study and the literature obviates the need to clarify optimal parameters for this specimen type.

Alabama↗
PubMed1999

Rescue of the skeletal phenotype of vitamin D receptor-ablated mice in the setting of normal mineral ion homeostasis: formal histomorphometric and biomechanical analyses.

1,25-Dihydroxyvitamin D3 has been shown to play an important role in vitro in regulating osteoblast gene transcription and promoting osteoclast differentiation. To address the role of the vitamin D receptor (VDR) in skeletal homeostasis, formal histomorphometric analyses were performed in VDR null mice in the setting of impaired mineral ion homeostasis as well as in VDR null mice in whom normal mineral ion homeostasis had been preserved. In hypocalcemic VDR null mice, there was an increase in bone volume as a result of a dramatic increase in osteoid. There was also an increase in the number of osteoblasts without a significant change in the number of osteoclasts. Examination of the growth plate revealed marked disorganization, with an increase in vascularity and matrix. Biomechanical parameters demonstrated increased bone fragility in the hypocalcemic VDR null mice. In the VDR ablated mice in whom normal mineral ion homeostasis had been preserved, none of these measurements was significantly different from those in wild-type littermates raised under identical conditions. Notably, the morphology and width of the growth plate were indistinguishable from those in wild-type controls, demonstrating that a calcium/phosphorus/lactose-enriched diet started at 16 days of age in the VDR null mice permits the development of both normal morphology in the growth cartilage and adjacent metaphysis and normal biomechanical competence of cortical bone. Thus, the principle action of the VDR in skeletal growth, maturation, and remodeling is its role in intestinal calcium absorption. The skeletal consequences of VDR ablation are a result of impaired intestinal calcium absorption and/or the resultant secondary hyperparathyroidism and hypophosphatemia.

Animals↗
PubMed1997

Fungal sinusitis.

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Diagnosis, Differential↗
PubMed1997

A new classification and diagnostic criteria for invasive fungal sinusitis.

OBJECTIVE: To develop criteria for the diagnosis of invasive fungal sinusitis. DESIGN: Review of the literature on invasive fungal sinusitis in the context of a population of 30 patients with fungal sinusitis and 24 patients with chronic bacterial sinusitis. SETTING: Tertiary care medical center. RESULTS: Our review revealed no consensus in the literature on the classification of the syndromes of invasive fungal sinusitis and no criteria for their diagnosis. Moreover, the existing syndromes of invasive fungal sinusitis lacked specificity and one of the more commonly cited syndromes, primary aspergillosis of the paranasal sinuses, is a granulomatous disease that occurs rarely outside Africa. Two of our 30 patients with fungal sinusitis had a previously unrecognized form of invasive disease. Both were middle-aged adults with well-controlled type 2 diabetes mellitus, apical orbital syndrome, and a similar course: proptosis resulting from fungal expansion out of an ethmoid sinus, a protracted illness of 6 months or longer, visual changes, late neurological symptoms reflecting cavernous sinus invasion, and death. The syndrome in these 2 patients is distinct from the syndrome of fulminant invasive fungal sinusitis, (eg, mucormycosis) with nasal eschar, intracerebral fungal dissemination by vascular invasion, and death in days, and the granulomatous form. CONCLUSIONS: We conclude that there are 3 forms of invasive fungal sinusitis and propose that they be termed (1) granulomatous, (2) acute fulminant, and (3) chronic invasive. The latter category reflects the syndrome seen in our 2 patients. Furthermore, the following 2 diagnostic criteria for invasive fungal sinusitis are proposed: (1) sinusitis confirmed by radiological imaging and (2) histopathological evidence of hyphal forms within sinus mucosa, submucosa, blood vessels, or bone. The specificity of hyphae within sinus mucosa for tissue invasion was supported by the absence of stainable hyphae in the mucosa of patients with chronic bacterial sinusitis or in the mucosa of our described patients with allergic fungal sinusitis and mycetoma.

Adult↗
PubMed1997

Criteria for the diagnosis of sinus mycetoma.

Recent improvements in the treatment options for fungal disease of the sinuses make rapid distinction between the syndromes of invasive and noninvasive sinusitis necessary. On the basis of the extensive review of the literature detailed here, we developed case-finding criteria for the noninvasive syndrome of sinus mycetoma. Using these criteria, we identified 20 cases of sinus mycetoma in the medical literature and compared findings in these patients to those of five patients with mycetoma evaluated in our clinics. Like those in the literature, our patients appeared immunocompetent and were often first seen for evaluation of symptoms other than those usually associated with sinusitis. Two were first seen with a new-onset seizure disorder and one with nasal obstruction alone. Patients from both groups more commonly had mycetoma in their maxillary sinuses, and fungus failed to grow from the cheesy, grey-green, hyphae-rich material removed at the time of surgery. Clinical features in our five patients, which are not noted in published reports of sinus mycetoma, included frequent atopy, nasal polyps, calcification within the sinus on computed tomography, and an excellent response to surgical treatment. Serendipitously, one patient had both allergic fungal sinusitis and a mycetoma in the same sinus. On the basis of this experience, we have modified our case-finding criteria into proposed diagnostic criteria for sinus mycetoma. The elements of these criteria are designed to: (1) exclude patients with invasive fungal sinusitis and (2) differentiate sinus mycetoma from other forms of noninvasive fungal sinusitis on the basis of specific histopathologic findings. This study and the criteria presented reflect our view that sinus mycetoma represents a distinct but not necessarily isolated element in the spectrum of noninvasive fungal disease of the sinuses.

Adult↗
PubMed1997

Evaluation of a rapid air thermal cycler for detection of Mycobacterium tuberculosis.

The Air Thermal Cycler (ATC) (Idaho Technology, Idaho Falls, Idaho) utilizes the unique technology of small-volume glass capillary tubes and high-velocity air for the heating and cooling medium for the PCR. Standard heat block thermal cycler (HBTC) and ATC performance characteristics were compared for the detection of Mycobacterium tuberculosis. Sensitivity was 100% for all smear-positive, M. tuberculosis culture-positive specimens for both the HBTC and the ATC. Of smear-negative, M. tuberculosis culture-positive specimens, sensitivity was 42.9% with the HBTC and 22.0% with the ATC. Specificity was 100% for both assay systems. Total assay time was 6.5 and 4 h and the reagent cost was 84 and 32 cents for the HBTC and ATC, respectively. The ATC offered an excellent alternative to the traditional HBTC for diagnosis of M. tuberculosis in smear-positive specimens by PCR.

Bacteriological Techniques↗
PubMed1996

Comparison of Bactec 9240 and Difco ESP blood culture systems for detection of organisms from vials whose entry was delayed.

A comparison of the Bactec 9240 (Becton-Dickinson, Sparks, Md.) and Difco ESP (Difco Laboratories, Detroit, Mich.) instruments for the detection of organism growth from vials whose entry was delayed was evaluated. The instruments' capabilities for organism recovery, time to detection, rates of false-positive results, and numbers of vials in which growth was not detected were made by using seeded blood culture vial pairs and controls with and without delayed entry. Bactec 9240 and Difco ESP aerobic and anaerobic vials were inoculated with human blood and were seeded with organism growth from 18 species, including obligate aerobic, anaerobic, and facultative anaerobic organisms. Each organism was tested in triplicate at 0, 8, 24, 36, and 48 h and was incubated at both room temperature (RT) and 35 degrees C. Two separate phases of the study were performed, each with a different version of Bactec 9240 software. Overall, detection of growth in vials with delayed entry into either the Bactec 9240 or the Difco ESP instrument resulted in an increased total time to detection with incubation at both RT and 35 degrees C compared with the total time to detection for nondelayed vials. However, false-positive results and vials in which growth was not detected were minimal, and delayed entry did not require routine entry or exit subcultures for either system. Analysis of individual time points and incubation temperatures for the detection of all organisms suggested that Difco ESP vials delayed by up to 8 h may be incubated at 35 degrees C (100% detection) and vials delayed for longer than 8 h may remain at RT. Bactec 9240 vials may be incubated at 35 degrees C for up to 24 h with a minimal loss of detection (97.9% detection), and vials delayed for more than 24 h should remain at RT for optimal recovery of organism growth.

Bacteremia↗
PubMed1995

Rapid identification of Staphylococcus aureus from blood culture bottles by a classic 2-hour tube coagulase test.

The rapid, reliable identification of Staphylococcus aureus from positive blood cultures provides important information. While multiple methodologies for detection of S. aureus from blood culture broths exist, none is satisfactory. Immunologic tests have shown varied sensitivities, the thermonuclease test, while sensitive, is not practical for routine use, and probe tests are expensive. Few studies have addressed using the tube coagulase test (TCT). This study compared two immunologic methods, the Staph Latex kit (Remel Laboratories) and the Staphaurex kit (Wellcome Diagnostics), with a rabbit plasma TCT (Difco Laboratories) to identify S. aureus within 2 h directly from blood culture broths and pelleted supernatants from BACTEC (Johnston Laboratories) bottles. One hundred twelve unique clinical blood culture isolates consistent with a Gram stain for staphylococci and 68 negative blood culture bottles seeded with a variety of gram-positive organisms were evaluated. Sensitivity and specificity among clinical specimens for the 2-h TCT were 79.5 and 100%, respectively. Sensitivities for the immunologic methods were 12.8 and 10.2% for the Staphaurex and Remel Staph Latex, respectively, and specificities for both were 100%. These results contradict previously reported results for both immunologic and TCT methods and dictate that a specific as well as a sensitive method be employed. The 2-h TCT was found to be a cost-effective, reliable, and rapid method for identifying S. aureus from positive blood cultures.

Bacterial Typing Techniques↗
PubMed1994

Correlations between the MMPI and the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms in schizophrenic patients.

Our study examined the relationship between the Minnesota Multiphasic Personality Inventory (MMPI) and the Scale for the Assessment of Positive Symptoms (SAPS; Andreason, 1984) and the Scale for the Assessment of Negative Symptoms (SANS; Andreason, 1983) in patients who met the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) diagnostic criteria for schizophrenia (n = 125). A significant correlation was found between the SAPS Delusions scale and Scale 6 (Paranoia), the SAPS Positive Thought Disorder Scale and Scale F (Infrequency), and the SAPS Positive Thought Disorder and Scale 9 (Hypomania). Additional analysis also shows, however, that severity of symptoms was the best predictor of MMPI scores. Consistent with previous studies, the MMPI appears useful for screening but not for the detailed evaluation of symptomatology of schizophrenic patients.

Adult↗
PubMed1992

Activation and facilitation in the lexicon of schizophrenics.

45 schizophrenic patients of three different subtypes (chronic undifferentiated, schizoaffective and paranoid) and 15 normal control subjects completed a semantic priming version of the lexical decision task. Schizophrenic subjects demonstrated longer reaction times relative to normal controls; however, all of the subjects showed semantic facilitation effects. No significant differences in reaction times were found among the three schizophrenic subtype groups. These results suggest that initial sensory-perceptual processing is unimpaired in schizophrenia and thus provide evidence of intact automatic processing. The similarity in performance among the schizophrenic subtype groups refutes the theory of a paranoid/non-paranoid dimension at the initial level of automatic processing.

Arousal↗
PubMed1986

Effect of medium composition on results of macrobroth dilution antifungal susceptibility testing of yeasts.

A total of 62 different clinical yeast isolates were examined for susceptibility to four antifungal agents, amphotericin B, 5-fluorocytosine (5-FC), ketoconazole, and miconazole, using synthetic amino acid medium-fungi (SAAM-F), buffered yeast nitrogen broth (BYNB), Kimmig broth, casein-yeast-glucose broth (CYG), antibiotic medium 3-FDA (ANTI-3), and tryptic soy broth (TSB). A macrobroth dilution format was used with MICs determined after incubation for 24 and 48 h. All analyses were performed in duplicate. In general, MICs were more reproducible after 48 h of incubation. Furthermore, with certain medium-antifungal agent combinations, MICs determined after incubation for 48 h were significantly higher than those determined after 24 h. For instance, with 5-FC irrespective of the medium used, greater than 25% of all 48-h MICs were more than one twofold dilution higher than the corresponding MICs determined after incubation for 24 h. Similar observations were made with amphotericin B when tested with BYNB and CYG and with the imidazoles when tested in all of the media except CYG. The actual MICs obtained with the different antifungal agents were clearly influenced by the test medium used. The rank order of amphotericin B MICs according to test medium was as follows: BYNB greater than SAAM-F = Kimmig = CYG = ANTI-3 = TSB. With 5-FC, the following pattern was observed: Kimmig = ANTI-3 greater than SAAM-F = CYG = TSB greater than BYNB. For both imidazoles, ketoconazole and miconazole, the rank order of MICs according to test medium was BYNB = Kimmig = CYG = ANTI-3 = TSB greater than SAAM-F. The results of this investigation suggested that broth dilution susceptibility testing of yeasts is best performed with an incubation period of 48 h. Furthermore, medium composition can significantly influence the results of such testing.

Amphotericin B↗
PubMed1985

Pharyngeal carriage rates of Haemophilus influenzae, type b and non-b, and prevalence of ampicillin-resistant Haemophilus influenzae among healthy day-care children in central Massachusetts.

Pharyngeal swabs were obtained from 832 children less than 14 years of age attending day-care centers and family day-care homes in central Massachusetts during a seven-week period beginning March 1, 1982. Colonization rates for Haemophilus influenzae and for H. influenzae type b were 60.7% and 15.1%, respectively. Nonwhite children were more likely to be carriers of non-b H. influenzae than white children (62.9% vs. 47.8%, p less than 0.025). Children in day care for more than six months were more likely to be carriers of non-b H. influenzae than children in day care for six months or less (52.9% vs. 45.5%, p less than 0.05). There was no association between colonization rates and age, sex, type of day-care setting, number of siblings, number sharing a bedroom, history of otitis media, or history of antibiotic use. The prevalence of ampicillin-resistant H. influenzae was 6.3% among all children and 10.3% among carriers of H. influenzae. The prevalence of ampicillin resistance was significantly higher among type b carriers than among carriers of other types (15.1% vs. 8.3%, p less than 0.05). Children who had taken ampicillin or amoxicillin within the past three months were much more likely to be colonized with ampicillin-resistant H. influenzae than were children who had not taken these antibiotics (13.5% vs. 4.8%, p less than 0.0005). These observations have important clinical implications for the management of children with H. influenzae disease.

Adolescent↗
PubMedDate not supplied

Impact of CLIA 88 on the clinical microbiology laboratory.

The Clinical Laboratory Improvement Amendments (CLIA 88) to the Clinical Laboratory Improvement Act of 1967 continues to undergo transformation since its implementation more than 2 years ago. The law and its subsequent regulatory modifications were intended to promote high quality in and accurate results from laboratory testing procedures, regardless of the site at which testing occurred. A number of federal regulatory agencies and committees such as the Healthcare Financing Administration, the Clinical Improved Amendments Committee, and the Commission on Laboratory Accreditation, as well as numerous new or modified regulations and requirements have gained importance since CLIA 88 was enacted. In this discussion, components of CLIA 88 that have the greatest impact on clinical microbiology laboratories are presented. In addition, the potential future significance of CLIA 88 are outlined.

Forms and Records Control↗