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PubMed2006

Effects of sex and hormone replacement therapy use on the prevalence of isolated impaired fasting glucose and isolated impaired glucose tolerance in subjects with a family history of type 2 diabetes.

Impaired fasting glucose (IFG) is more prevalent in men and impaired glucose tolerance (IGT) more prevalent in women. To explore whether this sex difference is related to female sex hormones, we performed a cross-sectional analysis of data from 2,164 (1,329 women and 835 men) first-degree relatives of individuals with type 2 diabetes. Subjects were categorized based on a 75-g oral glucose tolerance test. Sex and hormone replacement therapy (HRT) effects on the distribution of glucose tolerance were assessed using multinomial logistic regression corrected for familial clustering. Compared with men, women were more likely to have isolated IGT (relative risk 1.8 [95% CI 1.3-2.5]) and less likely to have isolated IFG (0.5 [0.3-0.7]) adjusted for ethnicity, age, waist, fasting insulin, and early insulin release (DeltaI(0-30)/DeltaG(0-30)). To evaluate HRT effects, postmenopausal women using (n = 238) or not using (n = 378) HRT were compared. HRT users were more likely to have isolated IGT (2.2 [1.2-4.0]) after adjustment, but the prevalence of isolated IFG did not differ by HRT status. Based on the influence of sex and HRT on the prevalence of isolated IFG and isolated IGT, we conclude that female sex hormones may play an important role in the pathogenesis of IFG and IGT.

Adult↗
PubMed1995

Isolation, characterization, and metabolism of the glycated and nonglycated subfractions of low-density lipoproteins isolated from type I diabetic patients and nondiabetic subjects.

The total low-density lipoprotein (LDL) fraction was isolated from 21 patients with type I diabetes and 7 nondiabetic normolipemic subjects. The LDL was separated into two subfractions, one glycated (G-LDL) and one nonglycated (N-LDL), using affinity chromatography. G-LDL comprised 21.1 +/- 3.6 and 5.2 +/- 0.6% of the total LDL in diabetic patients and normal subjects, respectively. G-LDL isolated from both diabetic patients and normal subjects was significantly more glycated than N-LDL isolated from the same subject. G-LDL isolated from both diabetic patients and normal subjects was enriched in triglycerides. The metabolism of N-LDL and G-LDL was investigated in human fibroblasts, which express only the classical LDL receptor, and in human monocyte-derived macrophages, which also express a receptor for G-LDL. In fibroblasts, the rates of receptor-mediated accumulation of N-LDL isolated from normal subjects and diabetic patients were significantly greater (P < 0.01) than those of G-LDL. In contrast, when the same LDL subfractions were incubated with human monocyte-derived macrophages, the rates of receptor-mediated accumulation of G-LDL isolated from both groups were significantly greater (P < 0.01) than those of N-LDL. Rates of degradation of G-LDL by human macrophages were not significantly different from those of N-LDL during short-term incubations but reached statistical significance (P < 0.05) when LDL subfractions were incubated with cells for 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2004

Differences in insulin resistance in nondiabetic subjects with isolated impaired glucose tolerance or isolated impaired fasting glucose.

Both impaired glucose tolerance (IGT) (as defined by the 1985 World Health Organization criteria) and impaired fasting glucose (IFG) (as defined by the 1997 American Diabetes Association criteria) represent intermediate metabolic states between normal and diabetic glucose homeostasis. Cardiovascular disease may be related to postglucose load rather than fasting glycemia, i.e., IGT rather than IFG. We hypothesized that subjects with IGT may be more insulin resistant and have higher levels of common cardiovascular risk factors than those with isolated IFG. In the Insulin Resistance Atherosclerosis Study (IRAS), we studied S(i) and first-phase insulin secretion (acute insulin response [AIR]), as derived from a frequently sampled intravenous glucose tolerance test, as well as common cardiovascular risk factors in four different glucose tolerance categories (NFG/NGT [n = 654], NFG/IGT [n = 255], IFG/NGT [n = 59], and IFG/IGT [n = 102]) among nondiabetic subjects. Subjects with isolated postchallenge hyperglycemia (NFG/IGT) had lower S(i) (means +/- SE: 2.10 +/- 0.04 vs. 2.59 +/- 0.13 x 10(-4) min(-1). microU(-1). ml(-1); P = 0.005), lower proinsulin levels (34.4 +/- 1.8 vs. 42.0 +/- 4.5 pmol/l; P = 0.03), higher AIR (273.1 +/- 18.1 vs. 215.9 +/- 30.0 pmol/l; P = 0.04), higher C-reactive protein (2.49 +/- 0.3 vs. 1.49 +/- 0.5 mg/l; P = 0.0015), and higher triglyceride levels (137.7 +/- 5.5 vs. 108.4 +/- 8.9 mg/dl; P = 0.0025) than subjects with isolated fasting hyperglycemia (IFG/NGT). The relation of insulin resistance to glucose tolerance category was consistently seen in women and men and across the three ethnic groups of the IRAS (non-Hispanic whites, African Americans, and Hispanics). Nondiabetic individuals with isolated postchallenge hyperglycemia (IGT) are more insulin resistant than individuals with isolated fasting hyperglycemia (IFG). The risk factor pattern (including increased insulin resistance) seen in isolated IGT identifies a subgroup of nondiabetic individuals who are likely to benefit from early intervention.

Adult↗
PubMed1999

Isolation and characterization of acid- and bile-tolerant isolates from strains of Lactobacillus acidophilus.

Lactic acid bacteria have been reported to be useful as a health adjunct and are commonly added to food as the delivery mechanism. The literature contains many conflicting observations for their proposed benefits, and the mechanism of action is undefined. One source of variation is the large number of strains used without proper controls supplemented. Additionally, many of the organisms are not characterized for their acid shock response or the acid-tolerance response, which are known to vary among bacterial species. Our objective was to isolate acid-resistant and bile-resistant variants of Lactobacillus acidophilus and to determine the phenotypic changes. The acid- and bile-tolerant isolates were obtained using natural selection techniques after sequential exposure to hydrochloric acid (pH 3.5 to 7.0) and mixed bile salts. The acid- and bile-tolerant isolates retained their ability to grow at pH 3.5 with 0.3% bile after the selective pressure was removed and reapplied. Isolates varied from their parents for stability in freezing, lactose utilization, protease activity, aminopeptidase activity, plasmid profile, and cell-wall fatty acid profile. These data suggest that the isolated acid- and bile-tolerant isolates possess growth advantages over that of the parents under stress conditions and may be considered as candidates for probiotic strains after further characterization with animal models.

Aminopeptidases↗
PubMed1991

Characterization of a Leishmania isolate from the rodent host Neotoma micropus collected in Texas and comparison with human isolates.

We report the biological and biochemical parameters of Leishmania parasites (MNEO/US/90/WR972) isolated from a rodent host, Neotoma micropus, collected in Texas. Footpad inoculations of WR972 promastigotes into BALB/c mice and Syrian hamsters resulted in ulcerating lesions six and eight weeks post-inoculation, respectively. Using monoclonal antibody-stained touch preparations, amastigotes were found in the liver of both laboratory hosts. Infection of J774 macrophages with WR972 promastigotes supported the growth of amastigotes for 12 days at 35 degrees C. The WR972 parasite was identified by enzyme electrophoresis as L. mexicana. Isozyme comparison of WR972 with 42 L. mexicana isolates (from humans and rodents) from four different endemic areas, including Texas, suggest that these parasite populations are identical for approximately 97% of their genetic loci. Pulse field gel electrophoresis (PFGE) of WR972 resolved 18 chromosomes with a size range of 300- greater than 2,000 kb. The karyotype strongly resembles that of two other Texas L. mexicana isolates from humans. Taken together, the PFGE, hybridization, and isoenzyme data suggest that the wood rat isolate (WR972) is identical to parasites from human cutaneous lesions isolated in Texas and Central America. In addition, the biological characteristics of WR972, its infectivity of BALB/c mice and the Syrian hamster, and the potential of the isolate to infect, transform, and divide in J774 macrophages indicate that WR972 will be pathogenic in humans if transmission occurs. Health care providers should consider this possibility when studying the epidemiology and control of cutaneous leishmaniasis in Texas.

Animals↗
PubMed2003

Isolation of Arcobacter spp. from retail meats and cytotoxic effects of isolates against vero cells.

A survey of Arcobacter spp. was conducted over a 12-month period in Guadalajara, Mexico. A total of 135 samples (45 lean ground beef samples, 45 lean ground pork samples, and 45 chicken samples, including drumsticks, gizzards, and ground or chopped breast) were collected from local butcheries. The samples were enriched in Johnson-Murano enrichment medium and then streaked onto Johnson-Murano agar plates. Typical colonies were subjected to microscopic and biochemical identification followed by polymerase chain reaction confirmation of the genus Arcobacter. All isolates confirmed to be Arcobacter isolates were then inoculated into Eagle's minimum essential medium to determine their cytotoxicity against Vero cells. Arcobacter spp. were detected in 28.8, 51.1, and 40.0% of beef, pork, and chicken samples, respectively. From these samples, 101 isolates were confirmed to be Arcobacter spp. by polymerase chain reaction. Overall, the species most frequently identified was A. butzleri, followed by A. skirrowii. A. cryaerophilus was isolated only from pork meat. Ninety-five (95%) of the Arcobacter isolates produced a virulence mechanism against Vero cells, and 38 of them induced cell elongation, indicating enterotoxin production. Eighteen isolates produced the formation of vacuoles, and 39 produced both vacuolization and elongation. The vacuolization effect may be related to a vacuolizing toxin. The production of a vacuolizing toxin by Arcobacter spp. has not previously been reported. Results obtained in this study indicate that Arcobacter spp. may show cytotoxic effects other than the recognized enterotoxin production.

Animals↗
PubMed1999

Isolation, identification and analysis of antibacterial activity of soil streptomycetes isolates from north Jordan.

A total of 90 different Streptomyces isolates were recovered from 36 soil samples and assessed for their antibacterial activity. Nine isolates were identified by the absence of an aerial mycelium. The rest were grouped into six colour series, namely grey, white, yellow, green, red and polymorphic colours (pink, orange or violet) with total numbers of 29, 18, 14, 8, 3 and 9, respectively. The isolates (68%) showed a reverse side culture pigmentation, 30% produced melanin and 25% produced other soluble pigments. Isolates (48%) were characterized by flexuous spore chains, 21% with spiral and 10% for each of the rectus and retinaculum apertum arrangement. The antibiotic activity against a wide range of bacteria was exhibited by 54% of the isolates which were effective against Bacillus subtilis (57%), Staphylococcus aureus (47%), Escherichia coli (24%), Klebsiella spp (16%), and Shigella spp (12%). The lowest activity (8%) was exhibited against Pseudomonas spp and Salmonella spp. The antibacterial activity of the isolates was divided into four groups according to the diameter of the inhibition zone produced. Groups 3 and 4 with larger inhibition zones indicated their potential as a possible source of novel antibiotics.

Anti-Bacterial Agents↗
PubMedDate not supplied

Molecular characterization of infectious bronchitis virus isolates foreign to the United States and comparison with United States isolates.

Eleven infectious bronchitis virus (IBV) isolates foreign to the United States were analyzed by using reverse transcriptase (RT)-polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) and S1 glycoprotein gene sequencing. Two of the isolates generated RFLP patterns that resembled the Mass 41 strain. Seven novel RFLP patterns were detected among the other nine foreign IBV isolates. Five of the foreign isolates were further analyzed by S1 glycoprotein gene sequencing in our laboratory. Phylogenetic analysis of S1 glycoprotein-deduced amino acid sequences for 4/91 pathogenic, 4/91 attenuated, and Variant 1 were greater than 90% similar to viruses belonging to the 793/B serogroup and, therefore, are possibly serologically related. Variant 2 was only 81.0% similar to viruses belonging to the European serogroup B, and, therefore, predicting its serotype is difficult. Isolates 98-07484 and 97-8123 were genotypically unique and therefore might be serologically unique. With the RFLP patterns and the deduced S1 amino acid sequence data as a reference, none of the IBV isolates foreign to the United States have been detected in the United States.

Amino Acid Sequence↗
PubMed2001

The crura and crura-sphincter pressure dynamics in patients with isolated upright and isolated supine reflux.

The reason why patients with isolated supine reflux do not reflux in the upright position and patients with isolated upright reflux do not reflux in the supine position is unknown. Our objective was to determine the characteristics of the crura, lower esophageal sphincter, crura-sphincter dynamics, and esophageal body on manometry, endoscopy, and X-ray in patients with isolated upright and isolated supine reflux. Eighty consecutive patients with isolated upright reflux were compared with 82 consecutive patients with isolated supine reflux. Manometrically there was no difference in lower esophageal sphincter characteristics and esophageal contractions between the two groups. The prevalence of a hiatal hernia on manometry was similar between upright and supine refluxers (88% vs 88%). Upright refluxers had shorter hiatal hernias [median (interquartile range) 1.1 (0.65-1.8) vs 1.2 (1-2.3), P < 0.046)]. The median crural pressure, crura-sphincter pressure gradient, and crura-sphincter pressure ratio in upright refluxers was 14.96 (9.5-21.27), 3.28 (1.7-12.2), and 1.33 (0.87-2.8) mm Hg, respectively. These values were significantly higher (P < 0.001) in supine refluxers at 21.43 (16.6-29.9), 10.66 (4.3-19.7), and 2.1 (1.3-4.2) mm Hg, respectively. We conclude that the significantly higher crural pressure in patients with supine reflux acts as a mechanical ring and as a physiologic protector against the unfolding of the sphincter in the postprandial and upright periods. Higher crura-sphincter pressure gradient and larger-size hiatal hernias in patients with supine reflux results in pressurization of the hernia sac and subsequent reflux when these patients are in a supine position.

Esophagus↗
PubMed2002

Isolation of serovar C-3 Haemophilus paragallinarum from Zimbabwe: A further indication of the need for the production of vaccines against infectious coryza containing local isolates of H. paragallinarum.

Various isolates of Haemophilus paragallinarum, collected from a severe outbreak of infectious coryza in poultry from Zimbabwe, were serotyped and were found to belong to serovar C-3. Previously, isolates were serotyped using polyclonal antiserum produced against serogroup reference strains (0083 for serogroup A, 0222 for serogroup B and Modesto, or H-18 for serogroup C) of H. paragallinarum. In this case, polyclonal antiserum produced against these reference isolates were used, as well as polyclonal antiserum that has been raised specifically against the serovar C-3 isolate 46 C-3. When using the latter serum at a 1 in 50 dilution, no cross-reaction with other members of serogroup C were found. The severity of the disease outbreak in Zimbabwe, the vaccination history of the infected flocks on the sites and the isolation of the uniquely southern African serovar C-3, further highlights the need for vaccines composed of local isolates to control infectious coryza in regions where vaccination failures occur.

Animals↗
PubMed2002

The Kümm isolate of Ehrlichia ruminantium: in vitro isolation, propagation and characterization.

An effective culture system for Ehrlichia (Cowdria) ruminantium comb. nov. was first established in 1985 and many stocks were subsequently isolated and propagated in vitro. A notable exception, however, was the Kümm isolate that resisted all attempts at in vitro culture until the successful experiment described here. In one experiment white blood cells were harvested from heparinized blood derived from a sheep infected with the Kümm isolate. The cells were added to DH 82 cells and incubated at 37 degrees C. The high metabolic activity of the DH 82 cells necessitated that cell growth be retarded by the addition of cycloheximide. Colonies were first detected 19 days after culture initiation and, once the cultures were established, they could be passaged every 3 days. Bovine and sheep endothelial cells were readily infected with culture supernatant obtained from the infected DH 82 cells. In a further experiment another sheep was infected, using a higher dose of the same batch of Kümm stabilate, and we attempted to infect several different cell lines: these were DH 82 cells, bovine aorta (BA 886) cells, sheep brain endothelial (SBE 189) cells and sheep fibroblastoid cells (E2). Ten days after culture initiation only the E2 cells had become positive for E. ruminantium. Culture supernatant from the first cultured isolate (Kümm-1) was less virulent for mice than that of the second cultured isolate (Kümm-2) which killed all mice. Upon molecular characterization with E. ruminantium 16S probes we found that Kümm-1 hybridized with a Senegal 16S genotype probe, whereas Kümm-2 hybridized only with an Omatjenne 16S genotype probe. The original stabilate used to infect the sheep hybridized with both probes. These results clearly indicate that two different stocks had been isolated in culture.

Animals↗
PubMed1979

Viruses isolated from Culicoides midges in South Africa during unsuccessful attempts to isolate bovine ephemeral fever virus.

Five viruses, unrelated to bovine ephemeral fever virus (BEFV), were isolated from Culicoides biting-midges collected during the summer months of the years 1968-69 and 1969-70 near a cattle herd in which cases of BEF occurred and at an open horse stable at Onderstepoort. These viruses were investigated by means of serological, electron-microscopical and physicochemical tests. It was established that 2 isolates, Cul. 1/69 and Cul. 2/69, were related to each other and belonged to the Palyam subgroup of the genus Orbivirus, that isolate Cul. 3/69 belonged to the equine encephalosis subgroup of the genus Orbivirus, while Cul. 1/70 was related to Akabane virus, which belongs to the Simbu subgroup of the family Bunyaviridae. One isolate, Cul. 5/69, though prevalent in the cattle population, could not be identified at this point. A brief serological survey indicated that the cattle in the nearby herd possessed antibodies against all the isolates except Cul. 3/69. BEFV could not be isolated in mice or in cultured cells from the wild-caught Culicoides.

Animals↗
PubMed1982

Isolation of bacteriophages for typing staphylococcus intermedius isolated from pigeons.

Attempts to isolate phages for typing Staphylococcus intermedius isolated from pigeons were made. Five phages were isolated from the lysogenic strains and the nostrils of pigeons, and were used for typing 50 strains isolated from pigeons in Japan, Belgium and Czechoslovakia. Thirty-one (62.0%) of the 50 strains were typed at either routine test dilution (RTD) or 100 X RTD into 8 phage patterns. A total of 122 strains of S. intermedius isolated from dogs, horses, mink and foxes were subjected to phage typing with pigeon phages, with the result that 10 (8.2%) of the 122 strains were typable. S. aureus and S. epidermidis, 59 and 58 strains, respectively, were resistant to lysis due to the pigeon phages. The experimental phages were considerably specific for S. intermedius isolated from pigeons.

Animals↗
PubMed1980

Isolation of haploid clones bearing a mating allele from a diploid apomictic isolate of Didymium iridis.

Clones of myxamoebae which fail to undergo a direct morphogenetic change into plasmodia have been isolated from cultures of the Philippine-1 isolates of Didymium iridis. These clones have been maintained continuously for a period of more than 4 years without producing plasmodia. It has been demonstrated by Feulgen-DNA cytophotometry that the mean nuclear DNA content of such clones is equivalent to the haploid replicated (2C) value. Conversely, myxamoebae which produce plasmodia directly have a mean nuclear DNA content which is equivalent to the diploid replicated (4C) value. The haploid Philippine-1 clones have been demonstrated to be cross compatible with isolates bearing the mating alleles A1, and A3 through A11, and incompatible with isolates bearing the mating allele A2. Furthermore, plasmodia which result from the crosses Ph-1n (A2) Hon 1-2 (A1), (A1), Ph-1n (A2) x Pan 2-4 (A7) and Ph-1n (A2) x Pan 2-7 (A8) have mean nuclear DNA values which are equivalent to the replicated diploid value, and produce spores which bear the mating alleles in the predicted ratios. Such data demonstrate that the Ph-1n clones are sexually compatible with haploid myxamoebae of heterothallic isolates. The significance of the isolation of these haploid clones with regard to a recent hypothesis related to the evolution of developmental systems in the Myxomycetes is discussed.

Alleles↗
PubMed1993

Antibiotic resistance pattern of heat-labile enterotoxin (LT) producing Escherichia coli isolated from children with diarrhoea in Bangladesh: clonal relationships among isolates with different resistant phenotypes.

Fifty-six heat-labile, enterotoxin-producing (LT+) Escherichia coli isolated from 33 children less than 5 years of age with diarrhoea were analysed for resistance to antibiotics, plasmid contents, and clonal relationships among isolates by ribosomal RNA (rRNA) fingerprinting (ribotyping). Fifty-five (98.2%) of the LT+ isolates were resistant either to tetracycline alone (48.2%) or to tetracycline and one or more other antibiotic, i.e. ampicillin, streptomycin, chloramphenicol, trimethoprim-sulfamethoxazole, or nalidixic acid. Most of the isolates harboured one or more plasmid but antibiotic resistance patterns did not always correlate with particular plasmid patterns. Ribotyping of the isolates using the restriction endonuclease EcoRI revealed a total of 7 different ribotypes, and ribotypes were shared by E. coli isolates with different antibiotic resistant phenotypes. The results indicate that in Bangladesh at least 7 different clones of LT+ E. coli acquired resistance to one or more different antibiotics in various combinations. However, a similar drug resistance pattern was not mediated by the same set of plasmids in all strains. The mechanism for the emergence and spread of antibiotic resistance among E. coli should be investigated further in Bangladesh, where LT+ E. coli is an important agent of early childhood diarrhoea.

Bacterial Toxins↗
PubMed1995

Multiresistance in Staphylococcus spp. blood isolates in Finland with special reference to the distribution of the mecA gene among the Staphylococcus epidermidis isolates. The Finnish Study Group for Antimicrobial Resistance.

A total of 570 Staphylococcus spp. blood isolates collected in Finland in 1991 were tested for susceptiblity to oxacillin and 19 additional antimicrobial agents. The Staphylococcus epidermidis isolates were also analyzed for the presence of the mecA gene by the polymerase chain reaction (PCR). Of the 238 S. epidermidis, 137 (58%) were in vitro identified as methicillin-resistant and 5 (2%) exhibited oxacillin MICs between 1 and 3 micrograms/ml. All these isolates were positive for the mecA gene in PCR as an indication of genetic resistance to methicillin, while none of the remaining 96 S. epidermidis isolates (oxacillin MICs < or = 0.25 microgram/ml) was positive. Multiresistance was observed in 123 (87%) of the 142 mecA-positive S. epidermidis. Of the 332 Staphylococcus aureus isolates, only one (0.3%) was phenotypically resistant to methicillin; the strain was also resistant to three other unrelated classes of antimicrobials. True methicillin resistance of this strain was manifested by the presence of the mecA gene in PCR. Based on these results, multiresistance was still extremely rate among the S. aureus in our country, whereas among the S. epidermidis as many as half of the blood isolates in central hospitals were multiresistant.

Bacterial Proteins↗
PubMed2002

The effects of age and isolation period on two phases of behavioral response to foot shock in isolation-reared rats.

Using rats as subjects, the effects of a period of isolation and the subjects' age during isolation on the response to foot shock were systematically examined in three experiments. Both the thresholds of shock that evoked a jumping response and that evoked a thrashing response were measured. The results suggest that the threshold for jumping response decreased when rats were isolated during the postweaning stage of development. On the other hand, the threshold for thrashing response decreased when the subjects were isolated for more than 39 days, independently of their age during isolation. Possible causes of the differential effects of these two factors are discussed in relation to the developmental process of these two behavioral indices.

Age Factors↗
PubMed1989

Isolation distress and maternal comfort responses of two-week-old rat pups reared in social isolation.

In 2-week-old rats, isolation from social companions in an unfamiliar place elicits ultrasonic vocalization rearing and locomotor behavior. These responses are prevented and close body contact is maintained if littermates or the dam are present. It has generally been believed that such isolation distress and comfort responses develop as a result of prior social experience. We reared pups in isolation from the third postnatal day and found essentially normal responses. A second experiment replicated and extended these results to pups reared in isolation from the day of birth. Isolation-reared pups did have higher levels of ultrasonic vocalization than their normally reared littermates, lower body weight, and lower post-test temperatures. We conclude that a lengthy period of close body contact and frequent social interactions with conspecifics are not necessary for the development of attachment responses in this species.

Animals↗