Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “INCUBATOR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed2001

Co-incubation of pig islet cells with spleen cells from non-obese diabetic mice causes decreased insulin release by non-T-cell- and T-cell-mediated mechanisms.

In vitro studies were conducted in the non-obese diabetic (NOD) mouse, prone to Type 1 autoimmune diabetes, to investigate the mechanisms involved in cell-mediated rejection of pig islet xenografts. Our previous work concerning the mechanisms of proliferation of xenogeneic lymphocytes to pig islet cells (PIC) was not indicative of PIC impairment. Consequently, a test was developed based on perifusion analysis of the alteration of basal and stimulated insulin release from adult PIC incubated with mouse splenocytes or subsets. Compared with PIC incubation alone or with syngeneic pig splenocytes, co-incubation with mouse whole spleen cells resulted in a decrease of basal and stimulated insulin release (P < 0.001). Two components of this alteration were detected separately: PIC impairment was decreased (P < 0.01) after removal of plastic-adherent cells from spleen cells, but maintained (P < 0.01) when plastic-adherent cells alone were co-incubated with PIC. The increase of murine interleukin-1 beta when mouse plastic-adherent spleen cells were cultured with PIC (P < 0.04) was indicative of macrophage activation. Soluble factors produced during co-incubation of mouse splenocytes or plastic-adherent cells with PIC were involved in the impairment process, since supernatant fluids collected during previous PIC-mouse cell co-incubations directly altered (P < 0.01) insulin release from PIC. Moreover, impairment of PIC by mouse spleen cells was abolished (P < 0.01) by gadolinium chloride (which inhibits macrophages), but not by cyclosporin A. Another mechanism was apparent, since co-incubation of PIC with purified mouse T cells or CD4+ T cells, re-mixed with antigen-presenting cells, led to a decrease (P < 0.01) of insulin release. This model, based on the alteration of dynamic basal and stimulated insulin release, is indicative of in vitro cell-mediated alteration of PIC in the NOD mouse. The effect of whole spleen cells was rapid, and a crucial role was played by plastic-adherent cells. Two mechanisms were responsible for the behaviour of these cells: an early direct effect (at least in part via soluble products); and the indirect presentation of PIC xenoantigens (leading to impairment by CD4+ T lymphocytes).

Animals↗
PubMed2001

Effects of long-term in vitro incubation of human spermatozoa: functional parameters and catalase effect.

Prolonged incubation of human spermatozoa can have deleterious effects on sperm function. The aim of this paper was to describe the effects of a prolonged in vitro incubation, under similar conditions to those employed in human assisted reproduction, on various sperm functional parameters, and to investigate the effect of an antioxidant (catalase) on this system. Freshly collected ejaculates from 20 healthy donors were studied. Samples were divided into two aliquots: the first was incubated with Ham's F10 containing 3.5% HAS, and the second was incubated in the same medium plus catalase (100 units ml-1). All experiments were carried out with spermatozoa isolated using the swim-up technique. Spermatozoa recovered from the supernatant after 1 h (T1) of incubation in 5% CO2 in air at 37 degrees C, and after 5 h (T6), 23 h (T24) and 47 h (T48), were evaluated for concentration, motion parameters including hyperactivation (computer-assisted analysis), viability, ATP concentration, reactive oxygen species (ROS) generation, DNA integrity (acridine orange), and acrosome reaction (AR). The major alteration observed in sperm function during the prolonged in vitro incubation was a reduction in the number of motile spermatozoa, together with an impairment in the quality of sperm movement. ROS levels increased with the incubation time. No substantial modifications of sperm viability, chromatin condensation and AR inducibility were observed. The addition of catalase to the medium, while keeping ROS values within baseline levels, did not prevent the loss of motility or the corresponding increase in ATP.

Acrosome Reaction↗
PubMed1994

Effect of incubation temperature on the gross pathology of turkey embryos.

1. Turkey eggs were incubated at 36.5, 37.5 and 38.5 degrees C. The age of mortality, the incidence of malpositions and the incidence of morphological abnormalities were recorded from all unhatched eggs. 2. Eggs incubated at 36.5 degrees C hatched later than eggs incubated at 37.5 degrees C but did not differ in age of mortality or incidence of malpositions and abnormalities. 3. Eggs incubated at 38.5 degrees C hatched significantly less well than eggs incubated at 37.5 degrees C and showed significant differences in time of embryo mortality. Overheated embryos had a mortality peak between 15 and 20 d of incubation and an increased mortality after 24 d of incubation. 4. Overheated eggs were characterised by a high incidence of embryos with head in small end, with excess albumen, ruptured yolk sacs, oedematous heads, eye cataracts and swollen down-plumules.

Animals↗
PubMed2000

Incubation period and sources of exposure for cutaneous Mycobacterium marinum infection: case report and review of the literature.

The diagnosis of cutaneous Mycobacterium marinum infection is often delayed for months after presentation, perhaps because important clinical clues in the patient's history are frequently overlooked. Knowledge of the incubation period allows the clinician to target questions about the patient's history. Prompted by a case with a prolonged incubation period, we sought to determine more precisely the incubation period of M. marinum infection. The MEDLINE database for the period 1966-1996 was searched for information regarding incubation period and type of exposure preceding M. marinum infection. Ninety-nine articles were identified, describing 652 cases. Forty cases had known incubation periods (median, 21 days; range, 5-270 days). Thirty-five percent of cases had an incubation period > or =30 days. Of 193 infections with known exposures, 49% were aquarium-related, 27.4% were related to fish or shellfish injuries, and 8.8% were related to injuries associated with saltwater or brackish water. Because the incubation period for cutaneous M. marinum infection can be prolonged, patients with atypical cutaneous infections should be questioned about high-risk exposures that may have occurred up to 9 months before the onset of symptoms.

Adult↗
PubMed1998

The effect of incubation periods under 95% oxygen on the stimulated acrosome reaction and motility of human spermatozoa.

Human sperm samples were prepared on a 30% Percoll gradient and reactive oxygen species (ROS) production was measured. In samples that generated ROS incubation under 95%O2:5%CO2 for 30 min decreased the proportion of spermatozoa capable of the stimulated acrosome reaction by 40% in comparison to samples incubated under 95%N2:5%CO2 (P< 0.001, repeated measures analysis of variance), but the degree of inhibition did not increase after more prolonged incubation periods (up to 6 h). The addition of the antioxidants catalase and superoxide dismutase prevented the inhibitory effect of 95%O2:5%CO2. Leukocyte removal from samples prior to 95%O2:5%CO2 incubation preserved the ability of the spermatozoa to acrosome react. Sperm motility parameters were less affected by 95%O2:5%CO2 but track velocity was 64.1 microm/s+/-1.96 after 2 h incubation under 95%N2:5%CO2 compared with 54.7 microm/s+/-1.41 after 2 h incubation under 95%O2:5%CO2 (P < 0.05, repeated measures analysis of variance). Sperm samples that did not generate detectable ROS were not affected by 95%O2:5%CO2. The toxic effects of incubation under 95%O2:5%CO2 on human spermatozoa result from increased endogenous ROS production, mostly from leukocytes. High ROS levels inhibit sperm function, with the stimulated acrosome reaction being more susceptible than motility parameters.

Acrosome Reaction↗
PubMed2001

Changes of the major sperm maturation-associated epididymal protein HE5 (CD52) on human ejaculated spermatozoa during incubation.

HE5 (CD52) is a glycoprotein which is secreted by the epididymis and which becomes inserted onto maturing spermatozoa. We have previously shown that, in cynomolgus monkey spermatozoa, changes occur upon maturation rendering cryptic the epitope to the monoclonal antibody CAMPATH-1G; the recognition site is then re-exposed during incubation under capacitation conditions. The present study investigated human ejaculated spermatozoa during incubation under similar conditions, using monoclonal antibodies that recognize different epitopes of the HE5 molecule comprising parts of the N-glycan (2E5) or peptide segments, including (CAMPATH-1G) or excluding (097) the glycosylphosphatidylinositol (GPI) anchor, to reveal modifications of sperm surface HE5. Flow cytometric analysis showed equally high percentages (approximately 90%) of viable spermatozoa cross-reacting with the antibodies before and after 6 h incubation. However, during incubation, the staining intensity increased 57% with CAMPATH-1G, 31% with 097, but remained unchanged with 2E5. The lymphocyte CD52 antibody CF1D12 stained only approximately 10% of spermatozoa either before or after incubation. Western blotting of sperm protein extracts using lectins indicated an increase in the exposure of sialic acid residues of HE5 after incubation. These results suggest that during incubation in capacitating conditions, there is an opening up of the HE5 glycoprotein molecule, increasing accessibility of some sialic acid residues and of the core peptide, particularly the GPI anchor.

Antibodies, Monoclonal↗
PubMed1992

Incubation period, severity of disease, and infecting dose: evidence from a Salmonella outbreak.

The associations between infecting dose, incubation period, and the severity of disease were examined in a large outbreak of Salmonella typhimurium which occurred at a medical conference in Wales in 1986. Persons who had eaten two or more pieces of the chicken vehicle had, on average, shorter geometric mean incubation periods than those who had only eaten one piece: 16.6 hours (95% confidence interval (CI) 13.5-20.5) compared with 20.7 hours (95% CI 19.0-22.6) (t = 1.97, p < 0.05). Incubation period was negatively correlated with the maximum frequency of diarrheal stools (r = -0.46, 95% CI -0.56 to -0.33), the maximum temperature reached (r = -0.34, 95% CI -0.50 to -0.16), the duration of symptoms (r = -0.41, 95% CI -0.53 to -0.26), and the amount of time taken off from work (r = -0.54, 95% CI -0.65 to -0.41). Those with shorter incubation periods were more likely to have been hospitalized. There was no association between chicken consumption and any of the measures of severity. The authors discuss the evidence that incubation period is inversely related to dose, the use of incubation period as a marker for dose, and the role that individual differences in susceptibility play in determining both the incubation period and the outcome.

Absenteeism↗
PubMed1989

The spontaneous acrosome reaction of human spermatozoa incubated in vitro.

Motile human sperm populations were prepared from liquefied semen (10 donors x 3 replicates) using Percoll density gradients at 30-60 min post-ejaculation. Sperm suspensions were incubated in a complex 'synthetic tubal fluid' culture medium (STF) at 37 degrees C under 5% CO2 in air for up to 36 h. Parallel aliquots were incubated with 50 microM A23187 to induce maximum acrosome loss (ARMAX). Acrosome reactions were assessed using both the triple-stain (TS) technique and fluorescent peanut agglutinin (PNA) lectin-labelling. During incubation, the proportion of TS acrosome reacted spermatozoa increased from 9.1 to 54.3% with ARMAX being 68.3%. Spermatozoa showing intact acrosomes by PNA labelling decreased from 68.4 to 26.1% over 36 h of incubation (ARMAX = 13.8%). Simultaneously, spermatozoa showing complete acrosomal loss (no PNA labelling) increased from 8.1 to 27.0% (ARMAX = 46.3%). Therefore, while only 23.5% of cells were actually undergoing acrosomal changes at the start of incubation, this had increased to 46.9% after 36 h (ARMAX = 40.7%). These experiments clearly show that even in selected populations, not all human spermatozoa are capable of undergoing an acrosome reaction. However, the incidence of acrosomal changes after 36 h of incubation did approach the ARMAX. These levels of spontaneous occurrence of the human sperm acrosome reaction were higher than those reported in many other in-vitro incubation studies: an improvement that may be attributable to the more physiological nature of the STF culture medium.

Acrosome↗
PubMed2002

Environmental incubation factors influence embryonic thyroid hormones.

Thyroid hormone responses in embryonic avian species are of two types, developmental and metabolic. Many studies have characterized the developmental function of the turkey embryonic thyroid, but few have characterized the metabolic function. Therefore, the purpose of this study was to describe the response of turkey embryonic thyroid hormones to three environmental factors. We proposed that embryonic thyroids from different genetic backgrounds would respond differently to changes in maternal diet and incubation temperature. Lines of turkeys known to have different embryonic growth and survival were examined in the current study. These eggs differ in egg weight, eggshell conductance, hatchling weight and organ maturity at the time of hatching. Eggs were produced throughout a 20 wk laying period and embryos were sampled at monthly intervals. Half of the hens producing the eggs were fed additional iodide in their diets, then, subsequently, half of each dietary treatment and line combination were incubated at either 36.8 C or 37.5 C to prolong the incubation period. Embryos were sampled during the final week of incubation when thyroid hormones become elevated to effect maturation and survival functions in turkey embryos. Embryonic thyroxine (T4) and triiodothyronine (T3) levels were assayed by RIA and compared among the treatments. Line, diet, and incubation period interacted to affect the levels of T4, T3 and T3 to T4 ratios in the turkey embryonic during late incubation. It was concluded that environmental factors can affect circulating thyroid hormone levels in turkey embryos, thus affecting metabolic functions, and the possibility exists to manipulate these circulating levels using environmental incubation conditions to improve hatchability.

Animal Feed↗
PubMed2002

Genetic control of incubation behavior in the domestic hen.

The genetic control of incubation behavior was investigated in the domestic hen by analysis of the incidence of the behavior in reciprocal crosses between nonbroody White Leghorn (WL) and broody Bantam (B) lines and in a backcross of F1 males (WL male x B female) and WL females. The hypothesis tested was that a sex-linked gene (or genes) plays a dominant role in the expression of incubation behavior. The incidence of incubation behavior was tested in hens held in floor pens with access to nests containing hard-boiled eggs during a 28-wk photoinduced laying cycle. The cycle was repeated if the behavior was not observed during the first cycle. The incidence of incubation behavior in B and WL hens was 78.6% (n = 28) and 0% (n = 28), respectively. Contrary to prediction, the incidence of incubation behavior in the WL male x B female and the B male x WL female crosses were not significantly different (61.6%, n = 73; and 56.8%, n = 37, respectively). The incidence of incubation behavior in the F1 backcross was 5.8% (n = 103), which was significantly less (P < 0.001) than predicted (39.3%). It was concluded that incubation behavior was not controlled by major genes on the Z chromosome. It was hypothesized that at least two dominant autosomal genes are involved, one causing and the other inhibiting the behavior with equal influence.

Animals↗
PubMed2004

Comparison of embryo physiological parameters during incubation, chick quality, and growth performance of three lines of broiler breeders differing in genetic composition and growth rate.

In broiler breeder management, stringent feed restriction is practiced to reduce body size in order to improve egg production and meet broiler production demand, but this practice has raised welfare issues. The potential for the dwarfing (dw) gene to reduce feed intake and body size of breeders under ad libitum feeding or less stringent restriction while maintaining improved egg production has been reported. In this study, we compared embryo physiology, quality of chicks, and performance of broilers from eggs of dwarf breeders with those from a standard broiler breeder. Hatching eggs from 3 commercial lines of broiler breeders were compared for incubation parameters, 1-d-old chick weight, chick quality, and broiler growth to 41 d of age. The lines included a standard heavy (S) line, an experimental (E) line, and a label-type (L) line. The E and L line breeders carry the sex-linked dw gene and are being used to assess the potential for dw to reduce feed intake or lower feed restriction and improve reproductive performance in heavy female broiler parent stock. Two separate experiments were conducted. All female parent stocks were mated to Cornish males, and fertile eggs were collected. In the first experiment, eggs were incubated for 21 d under standard conditions to determine, during final stages of incubation, corticosterone and thyroid hormone levels (triiodothyronine, T3; thyroxine, T4) in embryos and hatchlings, CO2 partial pressure (pCO2), and O2 partial pressure (pO2) in air cells, heat production by eggs and 1-d-old weights. In the second experiment, eggs were incubated for 21 d to compare chick quality, chick weights at 1 d of age, and broiler growth to 7 and 41 d. Average egg weights were higher for the S and L lines than the E line, but weight loss during incubation was lowest for the E line. Plasma T3 and T3/T4 ratio was similar between lines at IP, but corticosterone was higher in the S line. At hatch, T3/T4 ratio was higher in the S line compared with the E and L lines, but corticosterone was higher in the S and E lines than in the L line. Heat production by embryos was different among lines (S > E > L). The pCO2 was also higher in the S line than the E and L lines. These incubation parameters suggest different metabolic rates among lines (S > E > L). Incubation duration was shortest for the S line. Chick weights at 1 d old were not different between lines. Chick quality scores were also not different when expressed as a percentage of high-quality chicks or as an overall average score of each line. However, broiler BW at 7 and 41 d were different among lines (S > E > L). Chicks of higher quality (score of 100) in all lines had higher BW than those of lower quality (score of < 100). For corresponding quality groups between lines, the S line had higher BW, and those of the L had the lowest. These data suggest a link between the levels of embryo metabolism and growth potentials of the lines. We concluded that the dw gene has potential for reducing feed intake in heavy broiler parent stock (as in the E line), improving reproductive performance (as in the L and E lines), and maintaining progeny broiler chick weights at 1 d of age and quality but with lower weight at slaughter.

Animals↗
PubMed1987

Enhanced luteinizing hormone release by luteinizing hormone-releasing hormone in incubating female turkeys (Meleagris gallopavo).

To determine what role pituitary responsiveness plays in the suppression of gonadotropin level during incubation in the turkey, the ability of the pituitary to release luteinizing hormone (LH) in response to luteinizing hormone-releasing hormone (LHRH) was compared in incubating, laying, and photorefractory birds. In all three groups, the i.m. injection of LHRH (4 micrograms/kg) increased serum LH levels; however, the LH response was markedly enhanced in the incubating turkeys as compared with the laying (6.6-fold increase over preinjection levels vs. 1.9-fold; p less than 0.05) or the photorefractory birds (9.7-fold vs. 3.1-fold; p less than 0.05). The LHRH-induced LH release was also determined in turkeys as they shifted from the laying to the incubating phase of the reproductive cycle. This response increased (p less than 0.05) in magnitude as the birds started to incubate. The high prolactin level of incubating turkeys does not have a depressing effect on LHRH-stimulated LH release; thus, impaired LH response to LHRH is not a mechanism involved in the diminished gonadotropin secretion of incubating turkeys.

Animals↗
PubMed1988

Prostaglandin production by corpora lutea of rhesus monkeys: characterization of incubation conditions and examination of putative regulators.

Prostaglandins (PGs) are produced by the corpus luteum (CL) of many domestic and laboratory species and may play a role in CL regulation. The production of PGs by luteal tissue of the rhesus monkey has yet to be clearly elucidated. The production of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha by CL from rhesus monkeys and the incubation conditions (time and cell number) that permit assessment of their synthesis were examined. CL (n = 3 per characterization) were surgically removed from nonpregnant monkeys during the mid-luteal phase of the menstrual cycle (approximately 8-10 days after ovulation). Luteal tissue was dissociated and the cells were incubated at varying concentrations for increasing periods of time at 37 degrees C. Subsequent to defining incubation conditions, various exogenous factors were examined for their potential to modify PG production. Indomethacin, calcium ionophore, human chorionic gonadotropin (hCG), estradiol-17 beta (E2), progesterone (P), testosterone (T), dihydrotestosterone (DHT), and 1-4-6 androstatriene-3, 17-dione (ATD) were incubated with luteal cells in increasing doses. PG and P concentrations in the medium were determined by radioimmunoassay. PGs in the medium after 6 h incubation were detectable at all cell concentrations tested (50,000, 100,000, 200,000 cells/tube). Concentrations of PGs and P increased with cell number (p less than 0.05). Luteal cells (50,000 cells/tube) were incubated for times of 0-24 h. Concentrations of P, PGE2, and PGF2 alpha in the medium were relatively low prior to incubation (0 h), increased (p less than 0.05) linearly within the first 6-12 h, and plateaued through the remaining 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Theca cell cytochrome P450 17-hydroxylase and aromatase messenger ribonucleic acid abundance and serum steroid levels during follicular atresia associated with incubation behavior in the domestic turkey hen.

This study was designed to examine changes in cytochrome P450 17 alpha-hydroxylase (C17) and aromatase (ARO) mRNA contents in the theca layer of preovulatory follicles (POF) as turkey hens transit from egg laying to incubation. Hens were grouped into the following categories: 1) laying hens--laid one egg per day and nested 1-2 times per day; 2) transitional hens--laid one egg per day and nested > 4 times per day; and 3) Day 1, Day 3, and Day 5 incubating hens--laid no eggs for 2, 4, or 6 days, respectively, and nested > 4 times per day. Small white follicles (SWF) and the theca layer from the largest (F1) and the third (F3), fifth (F5), and seventh (F7) largest POF were dispersed and challenged with testosterone (T) for 5 h. Relative levels of C17 and ARO mRNA were examined from the theca layers of F1, F3, F5, F7, and SWF. The number of atretic follicles increased from 0 (layers) to 8 (Day 5 incubating hens). Serum LH, progesterone (P), and estradiol (E), but not T, declined on Day 1 of incubation. Basal levels of P, T, and E from theca and SWF cells declined in incubating hens. Both basal and T-stimulated theca and SWF production of E decreased in incubating hens. C17 and ARO mRNA declined in SWF, F7, and F5 during follicular atresia. It is suggested that reduced gene expression of ovarian steroidogenic enzymes may be a partial determinant of reduced circulating sex steroid levels in incubating hens.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Culture plate temperature and delayed incubation effect on bacterial recovery.

PURPOSE: To discover if initial culturing conditions (plate temperature and time delay to incubation) adversely influence the recovery of organisms associated with bacterial keratitis. METHODS: The rate of temperature equilibration of culture plates taken from a refrigerator and placed in an incubator and left on the desk was evaluated with a digital thermometer. A standard inoculum for each of five organisms (S. aureus, S. pneumoniae, P. aeruginosa, E. aerogenes, K. oxytoca) isolated from human bacterial keratitis was spread evenly on blood agar plates at refrigerator (Tcold; 4 degrees C), room (Troom; 24 degrees C), and incubator (Twarm; 37 degrees C) temperatures. The plates were then kept at room temperature for 0, 1, 3, 5, and 8 hours before overnight incubation at 37 degrees C (S. pneumoniae under microaerophilic conditions), and the number of colony-forming units was counted. RESULTS: Cold plates took at least 15 minutes in an incubator to attain room temperature, and up to an hour when left on the desk. Increased organism recovery was found comparing both Twarm and Troom plates (6.2 to 24.8% and 7.0 to 14.7%, respectively, P<0.001) to Tcold plates for all organisms except S. pneumoniae (P=0.057). Comparing Twarm plates to Troom plates demonstrated an increased recovery (P<0.001) for S. aureus. Delayed incubation resulted in decreased recovery for S. pneumoniae (P<0.001). CONCLUSIONS: Culture plates should preferably be warmed at least to room temperature before inoculation, as well as promptly incubated to increase bacterial recovery from cases of septic keratitis.

Bacteria↗
PubMed1987

Incubation periods and survival times for mice injected stereotaxically with three scrapie strains in different brain regions.

Incubation period and survival time were determined in C57BL mice which had been injected stereotaxically with either the 139A, ME7 or 22L strain of scrapie in one of five different brain regions (cerebral cortex, caudate nucleus, thalamus, substantia nigra, cerebellum). The injection of 139A in the caudate nucleus, thalamus, substantia nigra or cerebellum resulted in significantly shorter incubation periods than following cerebral cortex injection. For ME7, mice injected in the thalamus and cerebellum had incubation periods approximately 2 weeks shorter than the cerebral cortex group. For 22L, the incubation periods after substantia nigra or cerebellum injection were significantly shorter than after cortex injection. The cerebellum injection group had a significantly shorter incubation period than the substantia nigra injection group. The survival times for mice injected with a particular scrapie strain were directly related to the incubation periods. The groups with the shortest incubation also had the shortest survival time (e.g. 22L in the cerebellum). On histological examination, 139A and ME7 produced brain lesions in all brain areas regardless of injection site. For the 22L strain, after cerebellum injection vacuolation was limited to the cerebellum, while injection into the cerebral cortex and other forebrain regions resulted in vacuolation in all brain regions examined. Despite the difference in the distribution of vacuolation seen in cerebellum- compared to cortex-injected (22L) mice, infectivity titres were similar in the cortex, cerebellum, cerebellar cortex and medulla plus pons.

Animals↗
PubMed2004

Sensitivity of the BacT/ALERT FA-medium for detection of Pseudomonas aeruginosa in pre-incubated blood cultures and its temperature-dependence.

The BacT/ALERT FA-medium was evaluated to detect Pseudomonas aeruginosa in pre-incubated blood samples. As published previously its predecessor the BacT/ALERT FAN-medium failed to detect P. aeruginosa in delayed entry samples. It is now reported that FA-medium tolerates a longer pre-incubation period at 36 degrees C, i.e. 8 h, before detection of P. aeruginosa fails in experimentally inoculated blood cultures. In clinical blood samples the frequency of false-negative results concerning P. aeruginosa was reduced from 46.9 % (FAN-medium) to 9.1 % (FA-medium). If media inoculated with P. aeruginosa are pre-incubated at room temperature for 24 h, false-negative results are not observed. Various micro-organisms (Haemophilus influenzae, Streptococcus pneumoniae, Enterobacteriaceae, Staphylococcus aureus, Enterococcus faecalis, Candida glabrata) were recognized after pre-incubation at room temperature with similar sensitivity compared to pre-incubation at 36 degrees C. It is concluded that FA-medium detects P. aeruginosa in delayed entry samples with increased sensitivity and pre-incubation at room temperature is superior to pre-incubation at 36 degrees C.

Bacteriological Techniques↗
PubMed1997

Modification of mononuclear cell function after incubation with albumin-bound unsaturated fatty acids or soybean oil emulsion.

Administration of total parenteral nutrition (TPN) with soybean oil emulsion leads to a linoleic acid enrichment of the plasma membrane that may explain an in vivo activation of mononuclear cells (MNC) seen in our previous studies. Fatty acids from the lipid emulsion may have been accessible to MNC after endocytosis of lipid particles, or by direct uptake of fatty acids after lipoprotein lipase hydrolyzation of the emulsion triglycerides. To resemble the incorporation of fatty acids in vivo, we have modified MNC membrane lipid composition by incubation with different albumin-bound unsaturated fatty acids (UFA) or soybean oil emulsion. After incubation with albumin-bound linoleic and oleic acid, the unstimulated release of superoxide anion was unchanged, while zymosan-stimulated release was 140% (n.s) and 112% (p < 0.05) and phorbol-myristate-acetate (PMA)-stimulated release 148% (p < 0.05) and 124% (p < 0.05) of controls, respectively. Incubation with other UFAs or emulsion did not change superoxide anion release. Unstimulated lymphocyte proliferation increased 3 to 13-fold (p < 0.05) after incubation with all UFAs compared to controls, while UFA incubation did not change phytohemagglutinin (PHA) or PMA-stimulated proliferation. Unstimulated lymphocyte proliferation was decreased after incubation with emulsion, while PHA/PMA-stimulated proliferation was unchanged. Increase in membrane fluidity was detectable only after incubation with emulsion. The increased reactivity may have been caused by changes in the lipid environment surrounding membrane-bound enzymes important for signal transduction through the plasma membrane.

Cells, Cultured↗