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Biomedical subjects

R P Clay

Publications and source records attributed to R P Clay.

At least 19 recordsLinked to original sources
PubMed2004

Polygalacturonase-inhibiting proteins can function as activators of polygalacturonase.

The interaction between fungal endopolygalacturonases (EPGs) and polygalacturonase-inhibiting proteins (PGIPs) found in plant cell walls has been well established. The typical EPG/PGIP interaction is characterized by high affinity, reversibility, and a 1:1 stoichiometry that results in lowering the catalytic rate of a particular endopolygalacturonase by up to 99.7%. Various EPG and PGIP isoforms and glycoforms have been isolated and characterized, and combinations of EPGs and PGIPs demonstrate a range of enzyme inhibition. EPG/PGIP interactions have prompted many researchers to suspect the involvement of these proteins in the production of specific signals (oligosaccharins) during plant pathogenesis. We have recently reported on initial studies in our laboratory indicating that, for certain EPG/PGIP combinations, the specific activity of EPG is increased beyond that characteristic of the enzyme alone. In this paper, we present a detailed analysis of the product of the interaction of native Phaseolus vulgaris PGIP-2 with five EPGs from Aspergillus niger, namely PGI, PGII, PGA, PGB, and PGC in the presence of homogalacturonan. We demonstrate that for PGA and PGC, the interaction with PGIP-2 may result in either inhibition or activation in a manner that is pH dependent. This data suggests the need for a reevaluation of the conventional description applied to PGIPs; suggestions include polygalacturonase-binding protein and polygalacturonase-modulating protein.

Aspergillus niger↗
PubMed2001

Sexual selection on plumage and behavior in an avian hybrid zone: experimental tests of male-male interactions.

In western Panama, an unusual hybrid zone exists between white-collared manakins, Manacus candei, and golden-collared manakins, M. vitellinus. Unidirectional introgression of plumage traits from vitellinus into candei has created a region in which all definitively plumaged males have a collar that is lemon-colored. These males are nearly indistinguishable from white-collared candei genetically and morphometrically, but strongly resemble golden-collared vitellinus due to the introgression of secondary sexual plumage traits, particularly the lemon-colored collar. The introgression could be explained by sexual selection for golden-collared traits or by a series of mechanisms that do not invoke sexual selection (e.g., neutral diffusion, dominant allele). Sexual selection on male-male interactions implies behavioral differences among the plumage forms--specifically that golden- and lemon-collared males should be more aggressive than white-collared males. In contrast, the nonsexual hypotheses predict behavioral similarity between lemon- and white-collared males, based on their nearly identical genetics. We tested the sexual selection hypothesis experimentally, by presenting males with taxidermic mounts of the three forms. As response variables, we monitored vocalizations and attacks on the mounts by replicate subject males. Both golden-collared and lemon-collared males were more likely to attack than were white-collared males, as predicted under sexual selection but not by the nonsexual hypotheses. Lemon-collared males were more vocally reactive than either parental form, contrary to the prediction of the nonsexual hypotheses. Our study demonstrates that sexual selection on male-male interactions may play an important role in the dynamics of character evolution and hybrid zones.

Aggression↗
PubMed2000

Norian craniofacial repair system bone cement for the repair of craniofacial skeletal defects.

PURPOSE: To describe the use of the Norian Craniofacial Repair System (CRS) calcium phosphate bone cement in the restoration of craniofacial skeletal defects. METHODS: Consecutive case series. RESULTS: Calcium phosphate bone cement was used to repair craniofacial skeletal defects in three patients. Indications included repair of a posttraumatic orbital floor defect causing hypo-ophthalmos, reconstruction of frontal craniotomy and temporalis muscle donor sites in a patient who had undergone resection of an invasive squamous cell carcinoma, and augmentation of a post-traumatic anterior maxillary skeletal defect. The primary outcome measure was the restoration of bony volume and support. The use of calcium phosphate bone cement in these patients was effective and without complications. CONCLUSIONS: Norian CRS calcium phosphate bone cement is useful in the repair of craniofacial skeletal defects.

Adult↗
PubMed1999

Fungal polygalacturonases exhibit different substrate degradation patterns and differ in their susceptibilities to polygalacturonase-inhibiting proteins.

Polygalacturonic acid (PGA) was hydrolyzed by polygalacturonases (PGs) purified from six fungi. The oligogalacturonide products were analyzed by HPAEC-PAD (high performance anion exchange chromatography-pulsed amperimetric detection) to assess their relative amounts and degrees of polymerization. The abilities of the fungal PGs to reduce the viscosity of a solution of PGA were also determined. The potential abilities of four polygalacturonase-inhibiting proteins (PGIPs) from three plant species to inhibit or to modify the hydrolytic activity of the fungal PGs were determined by colorimetric and HPAEC-PAD analyses, respectively. Normalized activities of the different PGs acting upon the same substrate resulted in one of two distinct oligogalacturonide profiles. Viscometric analysis of the effect of PGs on the same substrate also supports two distinct patterns of cleavage. A wide range of susceptibility of the various PGs to inhibition by PGIPs was observed. The four PGs that were inhibited by all PGIPs tested exhibited an endo/exo mode of substrate cleavage, while the three PGs that were resistant to inhibition by one or more of the PGIPs proceed by a classic endo pattern of cleavage.

Amino Acid Sequence↗
PubMed1999

Familial gigantiform cementoma.

Familial gigantiform cementoma is a rare autosomal dominant tumor that is benign but can result in disfigurement of the facial skeleton. Two families with a total of five patients presented for treatment. Because of a lack of opportunity to obtain treatment early, three of the patients presented in adult life with massive tumors requiring extensive resection and complex reconstruction in multiple stages. The two female patients had chronic anemia caused by multifocal polypoid adenomas of the uterus and required hysterectomy before treatment. The last three patients had elevated alkaline phosphatase levels before tumor resection, and these levels decreased after surgery. With extensive resection of the tumors and reconstruction of both the soft tissues and facial skeleton, good functional and aesthetic results can be obtained. There has been no tumor recurrence with 3 years of follow-up.

Adult↗
PubMed1998

Microbiologic activity in laser resurfacing plume and debris.

BACKGROUND AND OBJECTIVE: With the increasing use of laser resurfacing, concerns have arisen about the biological hazards associated with the procedure. This study analyzed the potential bacterial and viral exposure to operating room personnel as a result of the laser smoke plume in CO2 laser resurfacing. STUDY DESIGN/MATERIALS AND METHODS: Thirteen consecutive patients underwent CO2 laser resurfacing. A HEPA filter in the smoke evacuator was used to collect specimens of the laser plume smoke for cultures. The study was controlled by a second filter exposed to room air. RESULTS: The 13 patients each had one bacterial, one viral, and one control culture (total, 39 specimens). In the control group, none of the 13 specimens had any growth. No viral growth has been found to date. Of 13 bacterial cultures, 5 resulted in growth of coagulase-negative Staphylococcus. Of these five positive specimens, one also had growth of Corynebacterium and one had growth of Neisseria. CONCLUSION: The potential exists for operating personnel to be exposed to viable bacteria during laser resurfacing.

Air Microbiology↗
PubMed1998

Klippel-Trénaunay syndrome: spectrum and management.

OBJECTIVE: To describe a series of 252 patients with Klippel-Trénaunay syndrome (KTS), a rare congenital malformation characterized by the triad of capillary malformations, atypical varicosities or venous malformations, and bony or soft tissue hypertrophy usually affecting one extremity. MATERIAL AND METHODS: We reviewed the clinical characteristics and findings in 136 female and 116 male patients with KTS who underwent assessment at Mayo Clinic Rochester between January 1956 and January 1995. In addition, management options are discussed. RESULTS: Capillary malformations (port-wine stains) were found in 246 patients (98%), varicosities or venous malformations in 182 (72%), and limb hypertrophy in 170 (67%). All three features of KTS were present in 159 patients (63%), and 93 (37%) had two of the three features. Atypical veins, including lateral veins and persistent sciatic vein, occurred in 182 patients (72%). Operations performed in 145 patients with KTS included epiphysiodesis, stripping of varicose veins or venous malformations, excision of vascular malformations, amputations, and debulking procedures. CONCLUSION: Most patients with KTS should be managed conservatively. The clearest indication for operation is a leg length discrepancy projected to exceed 2.0 cm at skeletal maturity, which can be treated with epiphysiodesis in the growing child. If a functioning deep vein system is present, removal of symptomatic varicosities or localized superficial venous malformations in selected patients can yield good results.

Adolescent↗
PubMed1997

Treatment outcome for 424 primary cases of clinical I cutaneous malignant melanoma of the head and neck.

BACKGROUND: Cutaneous malignant melanoma (CMM) is increasing in frequency. Surgery remains the primary and only curative treatment method. Our aim was to define prognostic factors and outcome predictors for patients with clinical stage I CMM of the head and neck. METHODS: Surgical treatment and outcome was analyzed for 424 patients with clinical stage I melanoma of the head and neck, completing initial treatment at the Mayo Clinic (1970-1990). The data were analyzed using the Kaplan-Meier product-limit method and Cox multiple-regression models. RESULTS: Overall, 180 (42%) patients underwent elective lymph node dissection (ELND) as part of the initial treatment; occult disease was demonstrated in 15 (8.3%). Among patients with tumor > 1.5 mm thick, occult regional disease was found in 15%. Failure of final treatment occurred in 152 (36%). Overall, 82% and 75% of the patients survived 5 and 10 years, respectively. CONCLUSIONS: Tumor thickness, extent of invasion, and the presence of occult region metastatic disease were the only independently predictive value (p < .005) of recurrence. The detection of disease by ELND did not appear to protect the patient from disease progression but identified those with regionally advanced disease and highest risk for recurrence. The development of recurrence significantly reduced but did not eliminate the potential for extended disease-free survival with subsequent treatment.

Adolescent↗
PubMed1997

Fistula formation and repair after palatal closure: an institutional perspective.

We retrospectively reviewed 119 consecutive patients who underwent cleft palate repair at the Mayo Clinic to determine the incidence of postoperative fistula formation, to assess possible contributing factors, and to review the methods of surgical management. Fistulas of the secondary palate were included, but nasal-alveolar fistulas and intentionally unrepaired anterior palatal fistulas were excluded. Six patients whose repairs were performed after 2.5 years of age were excluded to ensure a more uniform patient population. Cleft palate fistulas occurred in 13 of the 113 patients (11.5 percent). The median age at repair was 8.2 months, and the median follow-up period was 5.2 years. Several variables were analyzed by means of the log-rank test to determine their significance in postoperative fistula formation. Sex, extent of clefting (as estimated by the Veau classification), and type of palatal closure did not significantly affect the rate of fistula formation. However, patients who had palatal closure at an age younger than 12 months had a lower incidence of fistula formation (7.8 percent) than children whose closures were performed between the ages of 12 and 25 months (19.4 percent) (p = 0.058). The strongest predictor of the occurrence of a cleft palate fistula was the surgeon performing the procedure (p = 0.008). Fistula repair was deemed necessary in 11 of 13 patients, and 91 percent of these fistulas were healed with a single operation. Most of these fistulas were closed by using local flaps and two-layered closures. Cleft palate repair carries a significant but acceptable risk of fistula formation, which can be managed with local flaps. Fistula occurrence is related most to the experience level of the operating surgeon.

Child, Preschool↗
PubMed1997

Trends in the population-based incidence of squamous cell carcinoma of the skin first diagnosed between 1984 and 1992.

OBJECTIVE: To examine the incidence of first diagnosis of invasive squamous cell carcinoma (SCC) of the skin over time. DESIGN: Retrospective, population-based incidence study. SETTING: Enumerated, geographically isolated, semiurban population served by the Mayo Clinic and its affiliated hospitals and the Olmsted Medical Center, including its affiliated hospital in Rochester, Minn. METHODS: Using the Rochester Epidemiology Project databases that capture virtually all medical care provided to the residents of Rochester, we identified and reviewed records of all documented residents in whom histologically proven, invasive SCC of the skin was first diagnosed between 1984 and 1992. Age and sex stratum-specific rates were calculated, and age-adjusted rates observed over time for individuals aged 35 years or older were analyzed using Poisson regression. Adjusted rates were compared with the results of other studies. RESULTS: Review of 1630 records identified 511 incidence cases of SCC. Tumors located on the head and neck accounted for 66.4% of tumors in females and 72.9% in males. The annual age- and sex-specific incidence rates per 100,000 increased from 0 cases among males aged 0 to 14 years to 1286.0 cases among males aged 85 years or older. Over time, the annual age-adjusted incidence rates per 100,000 females rose from 46.5 (95% confidence interval [CI], 32.4-60.6) for the 1984 to 1986 period to 99.6 (95% CI, 80.4-118.7) for the 1990 to 1992 period and were 71.2 (95% CI, 61.7-80.8) overall. The corresponding rates for males were 125.9 (95% CI, 95.3-156.4), 191.0 (95% CI, 156.9-225.0), and 155.5 (95% CI, 137.0-174.0). The age- and sex-adjusted SCC incidence rates for the period from 1987 to 1989 and 1990 to 1992 exceeded those for the period from 1984 to 1986 (P = .03 and P < .001, respectively). Our age-adjusted rates for SCC were within the ranges seen in other white populations from temperate climates. CONCLUSION: The frequencies of first diagnosis of SCC are increasing at rates beyond those explainable by demographic shifts alone.

Adolescent↗
PubMed1995

Silicone thorax: a complication of tube thoracostomy in the presence of mammary implants.

Rupture of silicone breast implants is usually either iatrogenic or due to trauma. We present a case of blunt chest wall trauma in a patient with bilateral breast implants. Emergency chest tube thoracostomy resulted in rupture of one of the prostheses and caused subsequent migration of silicone into the chest cavity, where it led to empyema. The patient ultimately required a thoracotomy to evacuate the silicone and decorticate the lung. Review of the literature and methods to avoid this complication are described.

Breast Implants↗
PubMed1993

Management of intrathoracic defects.

Most intrathoracic transpositions involve the serratus anterior, pectoralis major, and latissimus dorsi muscles. These muscles provide an adequate mass and length of muscle for coverage of most structures in the mediastinum and have a single, dominant vascular axis. Winging of the scapula can occur with the harvest of the serratus anterior unless this is prevented by the maintenance of the upper two or three muscle slips as described previously. Even if winging does occur, we believe it to be a reasonable price to pay for control of the ongoing infection. Transposition of the latissimus dorsi and pectoralis major produce little if any significant cosmetic or functional defect in these ill patients. These muscles are transposed to assist in sealing of fistulas and to bolster vascular or visceral repair. We do not think that complete soft-tissue obliteration of the pleural cavity is necessary, and we continue to use the Clagett method of antibiotic-solution filling of the chest cavity at closure. In the irradiated patient with poor healing potential, intrathoracic muscle flaps may provide a means to salvage situations previously considered unsalvageable when the flaps are combined with sound principles of infection control; when used prophylactically, the flaps may prevent those same situations.

Humans↗
PubMed1992

Magnetic resonance imaging of facial vascular anomalies.

In 36 patients, facial vascular anomalies were studied with 46 magnetic resonance (MR) examinations, 9 angiograms, and 5 computed tomographic scans. All lesions were categorized into classic pathologic groups on the basis of radiologic and pathologic studies, clinical examination, and behavior. Overall, 2 juvenile hemangiomas, 3 capillary malformations (port-wine stains), 18 venous malformations, 9 lymphatic malformations, and 4 arteriovenous malformations were found. MR imaging was superior to computed tomography and angiography for demonstrating the precise anatomic extent of the facial vascular anomalies and their relationship to the adjacent soft tissues but was inferior to computed tomography for demonstrating radiopaque structures such as trophic bone changes and phleboliths. MR imaging was also inferior to angiography in determining the nidus and the exact nature of collateral vascular structures in arteriovenous malformations. MR studies confirmed the clinically suspected diagnosis of facial vascular anomalies and demonstrated typical characteristics for each type of lesion. MR imaging is an ideal initial technique to triage patients with facial vascular anomalies for appropriate management, including observation, endovascular therapy, or surgical excision.

Adolescent↗
PubMed1989

Ameloblastoma metastatic to the lung.

Ameloblastoma of the jaws is most often considered by clinicians to be a benign tumor with a distressing tendency for local recurrence. However, as the case presented here demonstrates, even in a patient without the characteristic history of multiple recurrences and operations, ameloblastoma may appear as a metastatic lesion, usually to the lung, many years after treatment of the primary tumor. This case is discussed, and the relevant literature concerning metastatic ameloblastoma is reviewed.

Aged↗
PubMed1986

Evaluation of broiler breeder pullet vaccination programs for preventing clinical reovirus infections in the progeny.

The efficacy of various reovirus vaccination programs in commercial broiler breeder pullets for preventing clinical reovirus infections in broiler progeny was studied in three experiments. In each, 70 1-day-old broilers from each of four different commercial poultry companies that used various combinations of live and killed reovirus vaccines in breeder pullets were used. Broiler progeny from each company were bled and serum analyzed for neutralization antibody to the S1133 reovirus. Twenty chicks from each company were challenged by foot pad with a virulent reovirus (S1133) and 20 chicks challenged with another reovirus (81-B) isolate to determine their susceptibility. An additional 20 chicks from each of the four groups were maintained as unchallenged controls. Chicks were examined for morbidity, mortality, and weight gain for a 3-week period. Three weeks after challenge, all chickens were necropsied for gross lesions. There was a direct correlation between the number of doses of live inactivated reovirus vaccines that pullets received to antibody titer and resistance to challenge in the day-old progeny. Day-old progeny derived from breeder pullets that received one dose of live and two doses of inactivated reovirus vaccines had the highest numerical maternal antibody titer and best resistance to clinical infection following challenge.

Animals↗
PubMed1986

Efficacy of coarse spray administration of commercial intermediate infectious bursal disease vaccines.

The efficacy of two intermediate infectious bursal disease (IBD) vaccines (Clone Vac D-78 and S-706) for immunizing specific pathogen-free (SPF) White Leghorn chickens by coarse spray (CS) against subclinical IBD was compared. Both intermediate IBD vaccines were equally capable of immunizing day-old SPF chickens by CS and were safe as evidenced by the absence of morbidity, mortality, or severe gross and microscopic bursal pathology at 28 days of age.

Animals↗