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SETTING The QuantiFERON®-TB Gold (QFT) assay is an interferon-gamma release assay used for the clinical diagnosis of latent tuberculous infection. Relatively high rates of indeterminate results are a significant downside of the test. OBJECTIVE To evaluate clinical variables associated with lower QFT-indeterminate rates after reducing pre-incubation delay. DESIGN In 2016, a new protocol of on-site incubation of QFT samples, followed by analysis at the outside laboratory, was implemented, resulting in much shorter pre-incubation delay of the samples. We retrospectively identified 3583 patients who underwent QFT before and after implementation of the new protocol. Patient records were scrutinized and QFT results were evaluated with respect to associated clinical conditions. RESULTS The patients were analyzed by dividing them into two cohorts based on maximum pre-incubation time (standard vs. immediate). Monthly indeterminate results dropped from 12.7% ± 0.02 in the standard cohort to 5.5% ± 0.03 in the immediate cohort (P < 0.001). A significant reduction in relative indeterminate rates was found in the immediate cohort patients with immunocompromised state, autoimmune conditions, liver disease and hypoalbuminemia. No difference was identified in patients with malignancies and renal failure. CONCLUSION Limiting the pre-incubation time to 1 h maximum significantly improved QFT performance, especially in patients from certain clinical categories.

Temperature extremes alter development, growth, hatching, and survival of eggs of ground-nesting birds, particularly during pre-incubation (egg laying) when eggs are left unattended and exposed to the environment for days or weeks before parental incubation begins. The northern bobwhite quail is a ground-nesting bird whose eggs experience high temperatures (≥45° C) during pre-incubation. It is known that chronic high temperatures during pre-incubation alter development and reduce hatching and survival of bobwhite eggs, but it is not known if acute doses of high temperatures during pre-incubation have the same effect. In this study, the 12-d pre-incubation period was divided into thirds. Fresh bobwhite eggs were exposed to either a commercial holding temperature for all 12 d (serving as a control), or a high oscillating temperature regimen for 4 d (one third of pre-incubation) either in the early, middle, or late third of pre-incubation, with a low oscillating temperature regimen during the remaining 8 d. The timing of acute exposure to high oscillating temperatures significantly affected bobwhite development. Eggs exposed in the first 2/3 of pre-incubation developed twice as much as eggs exposed late in pre-incubation, even though all eggs received the same amount of heating degree-hours. Thus, a critical window of thermal susceptibility exists for developing northern bobwhites. Acute exposure to high oscillating temperatures resulted in reduced hatchling mass, hatching success, survival, and compromised hatching synchrony. Thus, acute hyperthermic nest temperatures during pre-incubation could result in the observed reductions in the percentage of juveniles in natural populations during hot and droughty years.

In order to evaluate the effect of pre-incubation storage conditions on embryonic development and chick quality of Camperos breeders, 320 hatching eggs were selected. Before the incubation, they were kept for 4 days at a controlled storage and environment. Then, were kept for 21 days in the incubation process with the same technological conditions. Bioproductive performance on biological controls at 6, 11 and 18 days and at 21 days in hatchers were determined. Embryonic mortality and broken eggs were unchanged (p>0.05) during all the experiment. Also, at 6 days, clear eggs and the embryos with blood rings, tremulous air chamber and normal development and weak were not modified (p>0.05). Furthermore, at 11 days, the storage conditions did not affect the embryos with closed allantois and open (p>0.05). Similarly, at 18 days, the embryonic mortality and with and without air chamber head did not change according the pre-incubation storage conditions (p>0.05). In hatchers (21 days) the hatched chicks, first and second chicks showed no significant differences between treatments (p>0.05). These findings indicate that pre-incubation storage at environment temperature did not affect the embryonic development and chick quality of Camperos breeders on biological controls (6, 11 and 18 days) and hatchers (21 days), respectively.

Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture.

Department of Polymer Science and Engineering, Kyoto Institute of Technology,Matsugasaki-Hashigamichou 1, Sakyo-ku, Kyoto 606-8585, Japan(Received September 2, 2005; Accepted October 25, 2005; Published March 15, 2006)KEY WORDS Insulin / Amyloid / High Pressure / Protein / Denaturation / Aggregation /[DOI 10.1295/polymj.38.302]

Alcoholism is considered a physical dependence disorder. More than 18 million people are alcoholics in the USA and England and between 1/3 to ½ of them present some kind of physical disorder. In general the literature is focused on alcoholic trunk muscle disorders. These muscles have different embryological origins if compared to the masticatory muscles. The aim of this research was to evaluate the effects of alcohol on the masticatory muscles in order to compare them with the somitic muscles. For this purpose, 15 male Wistar rats weighing around 250g were used. The rats were divided into three groups: Normal control (N), Alcoholic (A) and Isocaloric (I). Slices of the masseter muscle, temporalis muscle and rectus abdominal muscle were harvested and submitted to histochemical reactions (m-ATPase: acid and alkaline pre incubation and NADH-TR). The myofibers were classified in SO, FOG and FG. The results showed atrophy of the fast fibers (FG and FOG) in the masticatory muscles but this atrophy was not statistically significant in this study (p< 0.05). On the other hand, significant atrophy occurred in the rectus abdominal muscle (p

1. Eggs were stored for two different times at varying temperatures. The effects on hatchability, chick weight at hatch and hatching time were examined in two broiler breeder lines from 33 to 58 weeks of age. 2. Short storage (1 to 3 d). Storage at 20 degrees C compared with 16.5 degrees C reduced hatchability of all eggs set. No effect was observed on hatchability of fertile eggs, hatching time or chick weight. 3. Long storage (9 to 11 d). Storage at 16.5 degrees C compared with 10 degrees C decreased both hatchability of fertile eggs and chick weight at hatch. Incidence of early embryonic death increased and incubation time decreased at 16.5 degrees C compared with 10 degrees C. 4. Chicks from morning eggs were heavier than those from afternoon eggs irrespective of storage conditions. 5. Hatchability (all eggs set and fertile eggs) and chick weight varied with hen age irrespective of storage conditions. During long storage, hatching time varied with hen age independently of breeder line, storage temperature or egg laying time. 6. Hatchability (all eggs set and fertile eggs) was higher in line A than in line B. Line B eggs hatched later and produced heavier chicks than line A eggs irrespective of storage time.

The aim of the study was to extend the survival of adult spinal motor neurons in serum free culture. Anterior half of the spinal cord was removed from young adult mice and dissociated. Cultured cells attempted to extend neurites within hours of incubation at 37 degrees C and died within 24 h. To prevent this early regenerative activity, thus to decrease the metabolic requirements of the neurons, cultures were transferred to 4 degrees C immediately after they were set and kept there for 3 days. Preparations were then taken to 37 degrees C where they lived up to 8 days. Some neurons continued to extend neurites until the day they died. To understand whether the enhancement of survival involves new protein synthesis, transcription and translation were blocked during cold pre-incubation, which shortened the half life of neurons but not changed the maximum survival period. In conclusion this study has shown that, in the serum-free cultures, the survival of adult spinal motor neurons can be significantly enhanced by cold pre-incubation whose effect seems to depend largely on a reduction in the metabolic activity and less on new protein synthesis. (c) 2012 Elsevier Ireland Ltd. All rights reserved.

In this work, the effect of pre-incubation conditions (temperature: 10, 15, 37 °C; pH 5.5, 6.5 and water activity, a w : 0.997, 0.960) was evaluated on the subsequent growth, survival and enterotoxin production (SE) of Staphylococcus aureus in cooked chicken breast incubated at 10 and 20 °C. Results showed the ability of S. aureus to survive at 10 °C when pre-incubated at low a w (0.960) what could constitute a food risk if osmotic stressed cells of S. aureus which form biofilms survive on dried surfaces, and they are transferred to cooked meat products by cross-contamination. Regarding growth at 20 °C, cells pre-incubated at pH 5.5 and a w 0.960 had a longer lag phase and a slower maximum growth rate. On the contrary, it was highlighted that pre-incubation at optimal conditions (37 °C/pH 6.5/a w 0.997) produced a better adaptation and a faster growth in meat products what would lead to a higher SE production. These findings can support the adoption of management strategies and preventive measures in food industries leading to avoid growth and SE production in meat products.

The effect of prior incubation temperature (5, 15, 25 and 35°C) on the lag times of two strains of Aeromonas hydrophila at the same four incubation temperatures was assessed. When grown at 5°C the type strain (ATCC 7966) showed a 28-fold difference in lag time depending on whether the inoculum had been incubated at 5 or 35°C. However, the corresponding factor for a food-derived strain was only 4. A similar effect was observed, to a lesser extent, under most of the conditions used. Prior incubation temperature had no effect on generation time.

Effects of pre-incubation upside-down positioning of eggs (from collection time at the farm until delivery to the hatchery, which can be up to 5 days) and breeder flock age on hatchability and chick quality were investigated. In this study, 5400 eggs from broiler breeder flocks were assigned to two groups (upside-down and normal position eggs as Control group). The birds were divided in three age groups (46, 73 and 107 weeks of age). Each age group had six replicates with 150 eggs per replicate. The results indicated that keeping eggs in an upside-down position reduced (P < 0.05) hatchability by 4.3% compared with the Control (normal position) group. Also, reversed egg positioning significantly increased relative intestine weight (P < 0.05) and percentage of embryo mortality between 18–19 days of incubation (P < 0.01). Flock age affected (P < 0.01) hatchability, egg shape index, chick cull percentage, infertile eggs, total embryo mortality, percentage egg weight loss and chick yield. The lowest hatchability and the highest percentage egg weight loss were observed in flocks with 107 weeks of age.

Thermal death of Cryptococcus neoformans in the presence of amphotericin B was strongly dependent upon the temperature of pre-incubation. The entropy coefficient, that is, the increase in entropy of activation of thermal death per square unit concentration of the drug in the medium, was 35 times higher after pre-incubation at 25 degrees C than at 39 degrees C. This means that C. neoformans cells grown at lower temperatures were much more sensitive to the temperature-dependent fungicidal effect of amphotericin B.

The kinetic measurement of serum alanine transaminase was carried out on 2 enzyme kits (Roche and Calbiochem), done as a direct method and a pre-incubation method. Variable results from commercial quality control sera and patient sera by these 4 procedures were obtained. Pre-incubation enzyme values were generally lower than the direct values (mean difference 10%), but there were marked differences between the results from the 2 kits. This finding has important significance especially for laboratories participating in external Q.C. programmes. A frequent precision check of the method and a local reference range are therefore necessary.

Anterior pituitary glands from intact diestrous female rats were incubated for two consecutive periods of 3 hours. During the first period various submaximally active amounts of luteinizing hormone-releasing hormone (LH-RH) were added to the media, whereas during the second period a supramaximally active concentration of LH-RH was present. When during the second incubation period protein synthesis was inhibited by cycloheximide, the amount of luteinizing hormone (LH) released during that period was positively correlated to the concentration of LH present during the first incubation period. This relationship was not seen when cycloheximide was absent, or when cycloheximide was present throughout both periods. Total LH was not affected by LH-RH; thus no effect of LH-RH on LH synthesis was observed. It is concluded that the amounts of protein synthesized by the pituitary glands in response to the different amounts of LH-RH during the first incubation period can constitute a limiting factor for the response to the supramaximally active amount of LH-RH added during the second incubation period.

It has been reported recently that major kinetic differences exist in the rate of iron uptake and of transferrin synthesis between intact seminiferous tubules and cultured Sertoli cells. To investigate possible causes of these differences, intact isolated rat seminiferous tubules were isolated and pre-incubated overnight. Then the rates of iron uptake and of transferrin synthesis were compared with those of freshly isolated tubules. We found that overnight pre-incubation increased the rate of both processes. Iron depletion was not the cause of these changes, since pre-incubation under iron excess gave comparable results. Possible explanations of these phenomena are discussed.

A possible source of discrepancy between kinetic and spectroscopic studies of the active site ionizations in the enzyme trypsin (EC 3.4.21.4) could arise if a slow pH-dependent conformational change affected the rates at low pH. No such effect is observed within the time range of 1 min- 3 h when pre-incubation of trypsin at pH 2.0 or at pH 6.9 precedes the enzymatic hydrolysis of Nalpha-carbobenzoxy-L-lysine-p-nitrophenyl ester. The deacylation rate of this hydrolysis depends on a single pKa on the enzyme between pH 3 and pH 7.

Since the publication of the original Salmonella mutagenicity test protocol in 1975, a number of investigators have proposed that the addition of a pre-incubation step to the normal protocol increases the sensitivity of the assay. Data presented here for 4-dimethylaminoazobenzene and the more potent carcinogenic analogue 6-dimethylaminophenylazobenzothiazole show that simply varying the amount of S9 present in the plate assay can increase the sensitivity of the test as much as the addition of the pre-incubation step does.

The misonidazole (MISO) “pre-incubation” effect, whereby the sensitiser-enhancement ratio (SER) is increased following prolonged exposure of cells in hypoxia to MISO, was first demonstrated by Hall and Biaglow (1977). Subsequently, Wong et al (1978) showed that hypoxic cells incubated with 0.5 mM MISO for several hours at 37°C had an increased sensitivity even when subsequently irradiated in air, reflecting a decrease in both the slope and the shoulder of the survival curve. Hall et al (1982) showed that V79 cells exposed to 5 mM MISO in hypoxia became more sensitive to radiation than oxic cells. Prolonged exposure of hypoxic cells to high concentrations of MISO is known to deplete the cells of their intracellular thiols (Biaglow et al, 1981) and it has been suggested that this depletion is, in part, the cause of the “pre-incubation” effect with radiation (Brown, 1981; Hall et al, 1982). There is also strong evidence to suggest that the depletion of cellular nonprotein thiols (NPSH) by MISO is important i...

The effects of the co-mutagen norharman on the mutagenicity of the rodent liver carcinogens 4-dimethyl-aminoazobenzene (DAB) and 3'-methyl-4-dimethyl-aminoazobenzene (3'-MeDAB) have been evaluated using the Ames Salmonella mutation assay. A period of pre-incubation was found to be necessary in order to detect DAB as a mutagen and to increase the initially weak response observed for 3'MeDAB; maximum responses were seen after 1 h pre-incubation in each case. The co-mutagenic properties of norharman were at their maximum for both azo-dyes in the direct plate-incorporation assay. Pre-incubation of either compound with norharman for increasing periods of time resulted in a decrease in potentiation, until after 1 h, an inhibition of mutagenicity was observed.

Mutagenic activity of a commercial ammonia caramel colouring was demonstrated in Salmonella typhimurium TA100 without metabolic activation. The activity in strain TA100 was increased using a 10-min pre-incubation, and a clear dose-response relationship was seen using this method. Investigation of samples taken from the different stages in the industrial process showed a constant level of mutagenic activity in samples from the middle to the end of the heating process with a steep increase in the sample taken after the end of heating. No mutagenic activity was seen in assays with S. typhimurium strains TA1535 and TA98

The viability of heat-stressed cells of Escherichia coli was influenced by the temperature of incubation prior and subsequent to heat treatment. The effect of pre-incubation temperature on the viability of heated cells was almost constant regardless of heating temperature in the range 48–54°C. The involvement of the change in fluidity of the membrane was suggested as a cause of the effects of pre-incubation and post-incubation. These phenomena were observed with other Gram negative and positive bacteria, and yeasts.

Using the back-titration method it was studied the influence of hemolysis upon radioimmunoassay of insulin. The degradation of immunoassayable insulin was increased by incubation with the increasing degree of hemolysis of plasma and with incubation period. The degradation of insulin was prevented when immediately after preparation the hemolytic plasma was incubated with anti-insulin serum.

A SHORT aerobic pre-incubation period before the onset of anaerobiosis greatly stimulates the rate of anaerobic glycolysis in slices of tissue. This fact, discovered by Rosenthal and Lasnitzky many years ago1, has later been confirmed2–4; but the mechanism of action of the previous incubation remains up to now largely unexplained.