Biomedical subjects

M Costello

Publications and source records attributed to M Costello.

At least 19 recordsLinked to original sources

PubMed2005

Gas-flushed packaging contributes to calcium lactate crystals in Cheddar cheese.

Gas-flushed packaging is commonly used for cheese shreds and cubes to prevent aggregation and loss of individual identity. Appearance of a white haze on cubed cheese is unappealing to consumers, who may refrain from buying, resulting in lost revenue to manufacturers. The objective of this study was to determine whether gas flushing of Cheddar cheese contributes to the occurrence of calcium lactate crystals (CLC). Cheddar cheese was manufactured using standard methods, with addition of starter culture, annatto, and chymosin. Two different cheese milk compositions were used: standard (lactose:protein = 1.47, protein:fat = 0.90, lactose = 4.8%) and ultrafiltered (UF; lactose:protein = 1.23, protein:fat = 0.84, lactose = 4.8%), with or without adjunct Lactobacillus curvatus. Curds were milled when whey reached 0.45% titratable acidity, and pressed for 16 h. After aging at 7.2 degrees C for 6 mo, cheeses were cubed (1 x 1 x 4 cm) and either vacuum-packaged or gas-flushed with carbon dioxide, nitrogen, or a 50:50 mixture of carbon dioxide and nitrogen, then aged for an additional 3 mo. Heavy crystals were observed on surfaces of all cubed cheeses that were gas-flushed, but not on cheeses that were vacuum-packaged. Cheeses without Lb. curvatus exhibited L(+)-CLC on surfaces, whereas cheeses with Lb. curvatus exhibited racemic mixtures of L(+)/D(-)-CLC throughout the cheese matrices. The results show that gas flushing (regardless of gas composition), milk composition, and presence of nonstarter lactic acid bacteria, can contribute to the development of CLC on cheese surfaces. These findings stress the importance of packaging to cheese quality.

Animals↗

PubMed2003

Development of a miniaturized four-culture method for the rapid enumeration of four bacterial groups in ground beef.

AIMS: A simplified and rapid method was developed to identify and enumerate total mesophilic microbial load, gram-negative bacteria, coliforms, and Escherichia coli in ground beef, using a single module. METHODS AND RESULTS: A 96-well microtiter plate was divided into four sections of two lanes (24 wells), with each section dedicated to each of the four critical bacterial groups. Double strength of four different selective broths (100 microl) was added to each well and an aliquot of sample (100 microl) from the first well was transferred to the next to achieve a twofold serial dilution in each series (24 wells). Initial bacterial load was calculated using the final consecutive positive reaction exhibiting color change or fluorescence. To validate the method, ground beef (n = 32), inoculated with a three-strain mixture of E. coli, together with 30 samples of commercial ground beef, were assayed by the four-culture method and conventional plating. For all media tested, the coefficients of determinations (r2) between the results derived from the four-culture method and those of conventional plating method ranged from 0.83 to 0.92. CONCLUSIONS: The high degree of association between the two methods indicates that the four-culture method could be easily applied to the enumeration of four critical bacterial groups in ground beef. SIGNIFICANCE AND IMPACT OF THE STUDY: This method will facilitate sanitation monitoring at meat processing plants by shortening time required for results, reducing consumable material costs, simplifying procedures, reducing the space required, and cutting the cost of start up equipment.

Animals↗

PubMed2002

Urinoma (para-ureteral pseudocyst) as a consequence of trauma in a cat.

A two-year-old cat was involved in a road traffic accident. Survey abdominal radiographs and urinary function were considered unremarkable. Six weeks later the cat presented with a palpable dorsal abdominal mass. Radiography revealed a soft tissue opacity mass caudal to the right kidney. Ultrasonography revealed a cyst-like structure with moderately echogenic contents, and right-sided hydronephrosis. There was no excretion of contrast medium from the right kidney after intravenous urography. Surgery revealed a disrupted right ureter adherent to the retroperitoneal mass. The mass contained serosanguineous fluid consistent with extravasated urine. Ureteronephrectomy was performed. The majority of the mass was excised and the cavity ablated. Histopathology of the excised tissue revealed a thick fibrous wall with no epithelial lining, consistent with a urinoma, which is thought to have developed as a consequence of ureteral trauma. The cat was clinically well three months postoperatively.

Animals↗

PubMed2001

Growth factor treatment enhances vestibular hair cell renewal and results in improved vestibular function.

The vestibules of adult guinea pigs were lesioned with gentamicin and then treated with perilymphatic infusion of either of two growth factor mixtures (i.e., GF I or GF II). GF I contained transforming growth factor alpha (TGFalpha), insulin-like growth factor type one (IGF-1), and retinoic acid (RA), whereas GF II contained those three factors and brain-derived neurotrophic factor. Treatment with GF I significantly enhanced vestibular hair cell renewal in ototoxin-damaged utricles and the maturation of stereociliary bundle morphology. The addition of brain-derived neurotrophic factor to the GF II infusion mixture resulted in the return of type 1 vestibular hair cells in ototoxin-damaged cristae, and improved vestibular function. These results suggest that growth factor therapy may be an effective treatment for balance disorders that are the result of hair cell dysfunction and/or loss.

Animals↗

PubMed2001

A client-centered approach to family planning: the Davao project.

The reproductive health approach to family planning shifts the focus of service provision from macro-level demographic objectives to meeting clients' needs. Little field experience exists to date, however, to indicate how to implement this approach. This study describes a field project in Davao del Norte and Compostela Valley provinces in the Philippines that implemented the reproductive health approach on a quasi-experimental basis. The intervention was designed to address clients' self-defined reproductive needs by providing them with relevant and accurate information and services of good quality. It consisted of two components: Providers were trained in information exchange at fixed clinics, and supervisors were trained in facilitative supervision. The results presented here indicate that the client-centered intervention was successful in enhancing service providers' knowledge and improving the content of information exchange between providers and clients. One provincial health officer has expanded the intervention throughout his province, while other provinces are interested in duplicating the model.

Adult↗

PubMed2001

Effects of testosterone and exercise on muscle leanness in eugonadal men with AIDS wasting.

Loss of lean body and muscle mass characterizes the acquired immunodeficiency syndrome (AIDS) wasting syndrome (AWS). Testosterone and exercise increase muscle mass in men with AWS, with unclear effects on muscle composition. We examined muscle composition in 54 eugonadal men with AWS who were randomized to 1) testosterone (200 mg im weekly) or placebo and simultaneously to 2) resistance training or no training in a 2 x 2 factorial design. At baseline and after 12 wk, we performed assessments of whole body composition by dual-energy X-ray absorptiometry and single-slice computed tomography for midthigh cross-sectional area and muscle composition. Leaner muscle has greater attenuation. Baseline muscle attenuation correlated inversely with whole body fat mass (r = -0.52, P = 0.0001). This relationship persisted in a model including age, body mass index, testosterone level, viral load, lean body mass, and thigh muscle cross-sectional area (P = 0.02). Testosterone (P = 0.03) and training (P = 0.03) increased muscle attenuation. These data demonstrate that thigh muscle attenuation by computed tomography varies inversely with whole body fat and increases with testosterone and training. Anabolic therapy in these patients increases muscle leanness.

Adult↗

PubMed2000

Effects of testosterone and progressive resistance training in eugonadal men with AIDS wasting. A randomized, controlled trial.

BACKGROUND: Substantial loss of muscle mass occurs among men with AIDS wasting. OBJECTIVE: To investigate the independent effects of testosterone therapy and progressive resistance training in eugonadal men with AIDS wasting. DESIGN: Randomized, controlled trial. SETTING: University hospital. PATIENTS: 54 eugonadal men with AIDS wasting (weight < 90% ideal body weight or weight loss > 10%). INTERVENTION: In a 2 x 2 factorial design, patients were assigned to receive testosterone enanthate (200 mg/wk) or placebo injections and progressive resistance training (three times weekly) or no training for 12 weeks. MEASUREMENTS: Cross-sectional muscle area and other indices of muscle mass. RESULTS: Cross-sectional muscle area increased in response to training compared with nontraining (change in arm muscle mass, 499 +/- 349 mm2 vs. 206 +/- 264 mm2 [P = 0.004]; change in leg muscle mass, 1106 +/- 854 mm2 vs. 523 +/- 872 mm2 [P = 0.045]) and in response to testosterone therapy compared with placebo (change in arm muscle mass, 512 +/- 371 mm2 vs. 194 +/- 215 mm2 [P< 0.001]; change in leg muscle mass, 1,236 +/- 881 mm2 vs. 399 +/- 729 mm2 [P = 0.002]). Levels of high-density lipoprotein cholesterol decreased in response to testosterone therapy compared with placebo (-0.03 +/- 0.13 mmol/L vs. 0.05 +/- 0.13 mmol/L [-1 +/- 5 mg/dL vs. 2 +/- 5 mg/dL]; P= 0.011) and increased in response to training compared with nontraining (0.05 +/- 0.13 mmol/L vs. 0.00 +/- 0.16 mmol/L [2 +/- 5 mg/dL vs. 0 +/- 6 mg/dL]; P = 0.052). CONCLUSIONS: In contrast to anabolic therapies that may have adverse effects on metabolic variables, supervised exercise effectively increases muscle mass and is associated with significant positive health benefits in eugonadal men with AIDS wasting.

Arm↗

PubMed2000

Size at birth and cord blood levels of insulin, insulin-like growth factor I (IGF-I), IGF-II, IGF-binding protein-1 (IGFBP-1), IGFBP-3, and the soluble IGF-II/mannose-6-phosphate receptor in term human infants. The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood.

Experimental rodent studies demonstrate that insulin-like growth factor II (IGF-II) promotes fetal growth, whereas the nonsignaling IGF-II receptor (IGF2R) is inhibitory; in humans their influence is as yet unclear. A soluble, circulating form of IGF2R inhibits IGF-II mediated DNA synthesis and may therefore restrain fetal growth. We measured cord blood levels of IGF-II, soluble IGF2R, insulin, IGF-I, IGF-binding protein-1 (IGFBP-1), and IGFBP-3 and examined their relationships to weight, length, head circumference, ponderal index, and placental weight at birth in 199 normal term singletons. IGF-II levels correlated with levels of IGF-I (r = 0.29; P < 0.0005), IGFBP-3 (r = 0.45; P < 0.0005), and soluble IGF2R (r = 0.20; P < 0.005). Insulin and IGF-I were positively related to all parameters of size at birth. IGF-II was weakly related to ponderal index (r = 0.18; P < 0.05) and placental weight (r = 0.18; P < 0.05), and the molar ratio of IGF-II to IGF2R was also related to birth weight (r = 0.15; P < 0.05). Correlations between the IGFs and size at birth were stronger in nonprimiparous pregnancies; in these, IGF-I (r = 0.52; P < 0.0005), IGFBP-3 (r = 0.41; P < 0.0005), and the IGF-II to IGF2R ratio (r = 0.40; P < 0.0005) were most closely related to placental weight, together accounting for 39% of its variance. We demonstrate for the first time relationships between circulating IGF-II and soluble IGF2R levels and size at birth, supporting their putative opposing roles in human fetal growth.

Body Constitution↗

PubMed2000

Evaluation of possible battlefield tourniquet systems for the far-forward setting.

A significant number of casualties in previous conflicts died from peripheral vascular wounds. A well-designed tourniquet could possibly have prevented these deaths. The objective of this study was the identification of such a tourniquet. A survey of Special Operations corpsmen established important characteristics necessary in an ideal tourniquet. Because most available devices do not and patented ideas could not meet these criteria, a number of prototypes were developed. Seven potentially satisfactory tourniquets were evaluated by 15 Navy SEAL corpsmen. The success and timing of placement were recorded, and a follow-up questionnaire was completed. Of the several successful tourniquets, two were preferred. Tourniquets incorporating a windlass technique take longer to place and often fail when placed with only one hand. New, relatively simple tourniquet devices incorporating bladder and ratchet mechanisms can significantly improve tourniquet performance.

Attitude of Health Personnel↗

PubMed1999

Decreased insulin-like growth factor-II/mannose 6-phosphate receptor expression enhances tumorigenicity in JEG-3 cells.

The insulin-like growth factor-II/mannose-6 phosphate receptor (IGF-II/M6PR) is believed to bind and degrade the potent mitogen IGF-II, a growth factor for many tumors. This receptor has been shown to be mutated and/or lost in a significant percentage of a variety of tumors, implying that it may act as a negative regulator of cell growth. In this study, we demonstrate that down-regulation of this receptor, mediated by antisense IGF-II/M6PR cDNA transfection into JEG-3 choriocarcinoma cells, results in increased growth rate in vitro and increased tumor growth rate in vivo. These findings demonstrate that a decrease in IGF-II/M6PR expression results in a growth advantage in JEG-3 cells and are consistent with the hypothesis that the IGF-II/M6PR is an inhibitor of tumor growth.

Animals↗

PubMed1999

Quantitative assessment of cross-sectional muscle area, functional status, and muscle strength in men with the acquired immunodeficiency syndrome wasting syndrome.

The acquired immunodeficiency syndrome wasting syndrome (AWS) in men is characterized by the loss of lean body mass out of proportion to weight. Although the wasting syndrome has been thought to contribute to reduced functional capacity, the relationships among lean body mass, muscle size, functional status, and regional muscle strength have not previously been investigated in this population. In this study, 24 eugonadal men with the AWS (weight <90% of the ideal body weight or weight loss >10% from preillness maximum) underwent determination of body composition by dual energy x-ray absorptiometry (DXA), 40K isotope analysis, urinary creatinine excretion, and quantitative computed tomographic analysis of cross-sectional muscle areas of the midarm and thigh. Overall exercise functional capacity was evaluated using the 6-min walk test, and performance of upper and lower extremities was determined with the quantitative muscle function test. Subjects were 37 +/- 1 yr of age and weighed 95.5 +/- 3.0% of ideal body weight, with a body mass index of 21.9 +/- 0.7 kg/m2 and an average weight loss of 15 +/- 1%. The mean CD4 count among the subjects was 354 +/- 70 cells/mm3, and viral load was 58,561 +/- 32,205 copies. Sixty-two percent of subjects were receiving protease inhibitor therapy. The subjects demonstrated 90% of the expected muscle mass by the creatinine height index method. Overall performance status on the Karnofsky scale was highly correlated to weight (r = 0.51; P = 0.018; by body mass index), lean body mass (r = 0.46; P = 0.036; by DXA), and body cell mass (r = 0.47; P = 0.037; by 40K isotope analysis). Cross-sectional muscle area of the upper extremity was the best predictor (P < 0.001) of Karnofsky score, accounting for 52% of the variability in a stepwise regression analysis. Upper body muscle strength was most significantly predicted by lean body mass (by DXA; r2 = 0.78; P < 0.0001), whereas lower body strength and performance on the 6-min walk test were best predicted by lower extremity cross-sectional muscle area (r2 = 0.70; P < 0.0001 and r2 = 0.26; P = 0.030, respectively). These data demonstrate that cross-sectional muscle area is highly predictive of functional status and muscle strength in men with the AWS.

Adult↗

PubMed1999

Regulation of soluble insulin-like growth factor II/mannose 6-phosphate receptor in human serum: measurement by enzyme-linked immunosorbent assay.

The soluble form of the insulin-like growth factor II/mannose 6-phosphate (IGF-II/M6-P) receptor has been detected in serum from a variety of mammalian species. We report the development of a highly sensitive quantitative human IGF-II/M6-P receptor immunoassay. Antibodies raised to receptor purified from a human hepatoma cell line by phosphomannan affinity chromatography were used to develop a specific enzyme-linked immunosorbent assay. In this assay, the serum level of soluble receptor for healthy adult subjects was 0.70 +/- 0.23 mg/L. We have shown that soluble receptor is developmentally regulated, with levels in infant (1.12 +/- 0.28 mg/L) and prepubertal (1.18 +/- 0.6 mg/L) subjects dropping by 40% during adolescence (0.73 +/- 0.61 mg/L) and remaining constant throughout adulthood. Further, the receptor is gestationally regulated, with a highly significant association between gestational age and maternal serum receptor levels (r = 0.947; P < 0.0001). Noninsulin-dependent diabetes mellitus (0.98 +/- 0.25 mg/L) and insulin-dependent diabetes mellitus (0.98 +/- 0.25 mg/L) mildly elevated soluble receptor levels, whereas end-stage renal failure (0.75 +/- 0.23 mg/L) and acromegaly (0.79 +/- 0.25 mg/L) did not affect receptor levels. Additionally, we have shown that soluble receptor is present in amniotic fluid, but at a 100-fold lower concentration than serum levels. The ability to quantitate soluble IGF-II/M6-P receptor levels in serum and other fluids provides a valuable tool that will help to further elucidate the role of the receptor in human physiology and disease states.

Acromegaly↗

PubMed1999

Determination of solid- and liquid-phase gastric emptying half times in cats by use of nuclear scintigraphy.

OBJECTIVE: To use nuclear scintigraphy to establish a range of gastric emptying half times (t1/2) following a liquid or solid meal in nonsedated cats. ANIMALS: 12 clinically normal 3-year-old domestic shorthair cats. PROCEDURE: A test meal of 75 g of scrambled eggs labeled with technetium Tc 99m tin colloid was fed to 10 of the cats, and solid-phase gastric emptying t1/2 were determined by use of nuclear scintigraphy. In a separate experiment, 8 of these cats plus an additional 2 cats were fed 18 ml (n = 5) or 36 ml (n = 5) of a nutrient liquid meal labeled with technetium Tc 99m pentetate. Liquid-phase gastric emptying t1/2 then were determined by use of scintigraphy. RESULTS: Solid-phase gastric emptying t1/2 were between 210 and 769 minutes (median, 330 minutes). Median liquid-phase gastric emptying t1/2 after ingestion of 18 or 36 ml of the test meal were 67 minutes (range, 60 to 96 minutes) and 117 minutes (range, 101 to 170 minutes), respectively. The median t1/2 determined for cats receiving 18 ml of the radiolabeled liquid was significantly less than that determined for cats receiving 36 ml of the test meal. CONCLUSIONS AND CLINICAL RELEVANCE: The protocol was tolerated by nonsedated cats. Solid-phase gastric emptying t1/2 were prolonged, compared with liquid-phase t1/2, and a major factor governing the emptying rate of liquids was the volume consumed. Nuclear scintigraphy may prove useful in assessing gastric motility disorders in cats.

Animals↗

PubMed1997

Structure of the calcium-binding echidna milk lysozyme at 1.9 A resolution.

A lysozyme isolated from the milk of a monotreme, the echidna, Tachyglossus aculeatus multiaculeatus, has been crystallized (space group P2(1), with unit-cell dimensions a = 37.1, b = 42.0, c = 38.1 A, beta = 91 degrees and Z = 2) and the structure refined to an R value of 0.167 for all measured data in the resolution range 7.0-1.9 A. It had previously been inferred from sequence homology with alpha-lactalbumins that echidna milk lysozyme (EML) would bind one calcium ion per molecule. This has been confirmed in the present study in which the largest peak in a difference Fourier synthesis is associated with a calcium ion. The calcium binding site of EML is very similar to that observed in baboon and human alpha-lactalbumins, and in a human lysozyme engineered to contain a calcium-binding site. The overall fold of the protein is similar to that of chick-type lysozymes. EML, like pigeon lysozyme, has only 125 residues terminating at a cysteine but in EML this forms a disulfide with a cysteine at residue 9 whereas the equivalent cysteine residue in all other lysozymes of known sequence occurs at position 6. These changes cause some minor structural rearrangements. The binding of calcium appears to have had little effect on the polypeptide backbone conformation and caused only small changes in the conformation of side chains coordinating the calcium ion. A homology modelling study [Acharya, Stuart, Phillips, McKenzie & Teahan (1994). J. Protein Chem. 13(6), 569-584] correctly predicted the overall structure of EML and the nature of its calcium binding site but generally failed to model some more subtle differences observed in the EML structure as evidenced by the fact that the homology model more closely resembles the starting structure from which the model was derived than it does the crystal structure.

Journal Article↗

PubMed1997