Control of Brackish Water Fouling Mussel, <Emphasis Type="Italic">Mytilopsis leucophaeata</Emphasis> (Conrad), with Sodium Hypochlorite

Though the Conrad's false mussel, Mytilopsis leucophaeata, is an important fouling animal in industrial cooling water systems, there are no published reports on the tolerance of this species to chlorination. A series of experiments was conducted to determine the effects of mussel size (2–20 mm shell length), season (breeding versus nonbreeding), nutritional status (fed versus starved) and acclimation temperature (5–30°C) on the mortality pattern of M. leucophaeata under continuous chlorination (0.25–5 mg/L). The effect of mussel size on M. leucophaeata mortality in the presence of chlorine was significant, with 10 mm size group mussels showing greater resistance. At 0.25 mg/L residual chlorine, 2 mm size group mussels took 89 days to reach 100% mortality, whereas 10 mm size group mussels took 109 days. M. leucophaeata collected during nonbreeding season (December–April) was more tolerant to chlorine than those collected during breeding season (June–October). Nutritional status of the mussel had no significant influence on the chlorine tolerance of the mussel: fed and starved mussels succumbed to chlorine at equal rates. The effect of acclimation temperature on M. leucophaeata mortality in the presence of chlorine was significant. At 0.5 mg/L residual chlorine, mussels acclimated at 5°C required 99 days to reach 95% mortality, whereas mussels acclimated at 30°C required 47 days. A comparison of present data with previous reports suggests that resistance of M. leucophaeata to chlorination is higher than other mussel species causing fouling problems in The Netherlands (Mytilus edulis and Dreissena polymorpha). Received: 18 October 2001/Accepted: 4 March 2002     

Increased Temperatures Affect Oxidative Stress Markers and Detoxification Response to Benzo[a]Pyrene Exposure in Mussel Mytilus galloprovincialis

The present research work was designed to study mussel’s (Mytilus galloprovincialis) digestive gland biotransformation and detoxification responses to benzo[a]pyrene (B[a]P) exposure along with heat stress. Mussels were exposed to a sublethal dose of B[a]P [75?nM (19?μg/L/animal)]?+?temperature gradient (18, 20, 22, 24 and 26?°C) for 7?days. B[a]P hydroxylase (BPH) and glutathione-S-transferase (GST) activities were assessed in digestive gland tissues as phase I and phase II biotransformation parameters. Catalase (CAT) activity and malonedialdehyde (MDA) were measured as potential biomarkers of oxidative stress and lipid peroxidation. The cholinergic system was evaluated using acetylcholinesterase (AChE) activity. DNA damage was assessed using micronuclei (MN) test. BPH and GST activities showed a decreasing trend in B[a]P-exposed animals at 24 and 26?°C. CAT activity showed a bell-shaped response in B[a]P-exposed and in heat-stressed organisms at a maximum temperature of 22?°C. AChE activity was significantly inhibited in response to B[a]P being more pronounced at a temperature of 26?°C. MN in digestive gland cells suggest that B[a]P exposure induced significant DNA alteration with a maximum response in organisms coexposed to B[a]P and a temperature of 26?°C. Biomarker data are further discussed in relation B[a]P accumulation in mussels digestive gland. These data should be carefully considered in view of the biological effects of organic pollutants, particularly in organisms under the challenging effects of extreme temperature fluctuations.     

The oral cholera vaccine Shanchol™ when stored at elevated temperatures maintains the safety and immunogenicity profile in Bangladeshi participants

BackgroundThe oral cholera vaccine (OCV), Shanchol™ has shown protective efficacy lasting up to 5 years, however, requirement for a cold chain limits its use in resource poor settings. The study was conducted to determine the safety and immunogenicity of Shanchol in adult participants in Bangladesh when stored at elevated temperatures.MethodsThe study was conducted in Mirpur, Dhaka. Four groups of healthy adult participants received two doses of Shanchol™, kept under standard storage temperature (Group A; 2–8 °C) or at elevated temperatures (Group B, 25 °C; Group C, 37 °C; Group D, 42 °C) for 14 days, respectively. Vaccine specific antibody responses were determined.Findings145 participants were assigned to each group. Adverse events were mild not differing among groups. Vaccine stored at elevated temperatures remained stable with cumulative LPS content within admissible limits.Vibriocidal antibody responses were observed in all groups after each dose of vaccine at day 7 and 21 compared to pre-immune levels (P < 0.001). Four-fold increases to Vibrio cholerae O1 Ogawa were observed at day 7 and/or day 21 after vaccination in the standard temperature and the three elevated temperature groups, with responder rates of; 76% (95% CI LB; 70%), 80% (95% CI LB; 74%), 69% (95% CI LB; 63%), and 74% (95% CI LB; 68%) in Groups A–D, respectively (P = 0.240). Responses were also seen in all groups to V. cholerae O1 Inaba and V. cholerae O139 and in LPS specific IgA response to V. cholerae O1 antigens.InterpretationThis is the first report to show that the OCV is stable at elevated temperatures, and the safety and immunogenicity profiles are not altered. This information will help formulate global policies for use of the vaccine at higher temperatures, resulting in easier distribution and vaccination costs and decrease logistical challenges to vaccine delivery.FundingBill & Melinda Gates Foundation.Trial registrationClinical Trials.gov number NCT01762930.     

Temperature in Nursing Home Residents Systematically Tested for SARS-CoV-2

ObjectivesMany nursing home residents infected with SARS-CoV-2 fail to be identified with standard screening for the associated COVID-19 syndrome. Current nursing home COVID-19 screening guidance includes assessment for fever, defined as a temperature of at least 38.0°C. The objective of this study was to describe the temperature changes before and after universal testing for SARS-CoV-2 in nursing home residents.DesignCohort study.Setting and ParticipantsThe Veterans Administration (VA) operates 134 Community Living Centers (CLC), similar to nursing homes, that house residents who cannot live independently. VA guidance to CLCs directed daily clinical screening for COVID-19 that included temperature assessment.MeasuresAll CLC residents (n = 7325) underwent SARS-CoV-2 testing. We report the temperature in the window of 14 days before and after universal SARS-CoV-2 testing among CLC residents. Baseline temperature was calculated for 5 days before the study window.ResultsSARS-CoV-2 was identified in 443 (6.0%) residents. The average maximum temperature in SARS-CoV-2–positive residents was 37.66 (0.69) compared with 37.11 (0.36) (P = .001) in SARS-CoV-2–negative residents. Temperatures in those with SARS-CoV-2 began rising 7 days before testing and remained elevated during the 14-day follow-up. Among SARS-CoV-2–positive residents, only 26.6% (n = 118) met the fever threshold of 38.0°C during the survey period. Most residents (62.5%, n = 277) with confirmed SARS-CoV-2 did experience 2 or more 0.5°C elevations above their baseline values. One cohort of SARS-CoV-2 residents' (20.3%, n = 90) temperatures never deviated >0.5°C from baseline.Conclusions and ImplicationsA single screening for temperature is unlikely to detect nursing home residents with SARS-CoV-2. Repeated temperature measurement with a patient-derived baseline can increase sensitivity. The current fever threshold as a screening criteria for SARS-CoV-2 infection should be reconsidered.     

Thermal and Biocidal (Chlorine) Effects on Select Freshwater Plankton

Impact of select levels of temperature, individually and in combination, with different initial chlorine concentrations on the growth and reproduction of phytoplankter Chlorella vulgaris and zooplankton C. reticulata, C. viridis, and Diaptomus forbesi was evaluated. During the experiment, optimum growth temperature for the alga was estimated as 26°C, even though alga showed considerable growth up to 36°C. However, initial chlorine at concentrations ≥0.25 mg l⁻¹ adversely affected growth (P < 0.05 to 0.001) at all select temperature levels (26°C, 31°C, 33°C, 36°C, 39°C, 42°C, and 45°C). Investigations toward effects of different temperatures (26°C, 31°C, 33°C, and 36°C) on zooplankton indicated that survivability of these organisms was affected at temperatures ≥33°C. However, the percent growth rates of zooplankters at 26°C were significantly higher (P < 0.05) than those at 31°C, 33°C, and 36°C. Initial chlorine levels of 0.5 and 0.25 mg l⁻¹ were lethal to zooplankton; however, zooplankton survival was not affected at 0.06 mg l⁻¹ chlorinated water at all selected temperatures.     

Factors promoting in vitro excystation of Giardia muris cysts

Giardia muris cysts, isolated from mouse faeces, excysted routinely at levels greater than 90%, when induced in IX Hanks' supplemented with 17 mM glutathione, 29 mM L-cysteine-HCl, and 50 mM NaHCO₃ for 30 minutes at 35 °C, followed by washing and suspension in trypsin-Tyrode's solution at pH 8·0. Although trypsin was not required in this final step, it enhanced the escape of the trophozoites from their cysts. G. muris excystation was dependent upon the length of the induction period, pH, oxidation-reduction potential and temperature. Optimal induction conditions for excystation were: an induction period of 5 to 30 min; pH of 2; 120 mV oxidation-reduction potential; and a temperature around 35 °C. A gradual decline in excystation occurred as pH and oxidation-reduction potential were changed to 7 and 57 mV, respectively. There was a pronounced increase in excystation percentages with increasing temperatures between 0 and 37 °C. At 40 °C and above, the G. muris cysts showed signs of inactivation. The thermal death point of G. muris cysts was determined to be about 54 °C. G. muris cysts showed no polarity; however, the tail or posterior trophozoite portion always emerged through one end of the cyst first. Cytokinensis began within the first hour after excystation. This method always produced extremely active, normal-looking G. muris trophozoites.     

The recommended Threshold Limit Values for heat exposure fail to maintain body core temperature within safe limits in older working adults

Purpose: The American Conference of Governmental and Industrial Hygienists (ACGIH®) Threshold Limit Values (TLV® guidelines) for work in the heat consist of work-rest (WR) allocations designed to ensure a stable core temperature that does not exceed 38°C. However, the TLV® guidelines have not been validated in older workers. This is an important shortcoming given that adults as young as 40 years demonstrate impairments in their ability to dissipate heat. We therefore evaluated body temperature responses in older adults during work performed in accordance to the TLV® recommended guidelines.

Methods: On three occasions, 9 healthy older (58 ± 5 years) males performed a 120-min work-simulated protocol in accordance with the TLV® guidelines for moderate-to-heavy intensity work (360 W fixed rate of heat production) in different wet-bulb globe temperatures (WBGT). The first was 120 min of continuous (CON) cycling at 28.0°C WBGT (CON[28°C]). The other two protocols were 15-min intermittent work bouts performed with different WR cycles and WBGT: (i) WR of 3:1 at 29.0°C (WR3:1[29°C]) and (ii) WR of 1:1 at 30.0°C (WR1:1[30°C]). Rectal temperature was measured continuously. The rate of change in mean body temperature was determined via thermometry (weighting coefficients: rectal, 0.9; mean skin temperature, 0.1) and direct calorimetry.

Results: Rectal temperature exceeded 38°C in all participants in CON[28°C] and WR3:1[29°C] whereas a statistically similar proportion of workers exceeded 38°C in WR1:1[30°C] (χ²; P = 0.32). The average time for rectal temperature to reach 38°C was: CON[28°C], 53 ± 7; WR3:1[29°C], 79 ± 11; and WR1:1[30°C], 100 ± 29 min. Finally, while a stable mean body temperature was not achieved in any work condition as measured by thermometry (i.e., >0°C·min^?1; all P<0.01), heat balance as determined by direct calorimetry was achieved in WR3:1[29°C] and WR1:1[30°C] (both P ≥ 0.08).

Conclusion: Our findings indicate that the TLV® guidelines do not prevent body core temperature from exceeding 38°C in older workers. Furthermore, a stable core temperature was not achieved within safe limits (i.e., ≤38°C) indicating that the TLV® guidelines may not adequately protect all individuals during work in hot conditions.     

Effect of temperature on physiology and bioenergetics of adult Harris mud crab Rhithropanopeus harrisii (Gould, 1841) from the southern Baltic Sea

Rates of physiological processes and bioenergetics of the Harris mud crab Rhithropanopeus harrisii were determined during a 7-day experiment on adult males (mean wet weight 0.83 ± 0.16 g) exposed to temperatures of 15°C and 20°C (S = 7). The results show that the change in temperature by 5°C caused detectable changes in locomotor activity, food consumption and faeces production and significant (p < 0.05) changes in metabolic rates. Food assimilation efficiency and the ammonia excretion rate did not change significantly (p > 0.05). The energy expended on metabolic processes was similar at both temperatures (15°C and 20°C) and amounted to 17.7 ± 6.4% and 16.7 ± 4.3% of the assimilated energy, respectively. Similar values were obtained for net production efficiency K2 (P/A) at 15°C and 20°C, i.e. 80.4 ± 22.4% and 82.9 ± 9.7%, respectively. The amount of energy available for production was 2-fold higher at a temperature of 20°C than at 15°C and amounted to 103.69 ± 25.61 and 206.40 ± 20.76 J d^?1g^?1 wet wt, respectively. The results show that from the bioenergetic point of view, higher experimental temperature is more “profitable” for adult R. harrisii specimens because it provides better conditions for the growth and reproduction.     

Successful cryopreservation of Brugia pahangi third-stage larvae in liquid nitrogen

Experiments are described which lead to the retention of infectivity of Brugia pahangi third-stage larvae after cooling to ?196 °C. Methanol, a well documented cryoprotectant was used at a concentration of 20% (v/v). The schedule consisted of a 5 °C min^?1 cool to an intermediate temperature of ?21 °C and a subsequent rapid cool into liquid nitrogen. A rapid thaw of the parasites led to approximately 34% of motile cryopreserved larvae developing in multimammate rats (Mastomys natalensis) compared to unfrozen control larvae. Cooling rate and intermediate temperature were both found to be crucial variables affecting survival levels of the larvae.     

The physiological strain incurred during electrical utilities work over consecutive work shifts in hot environments: A case report

Purpose: In this article, we evaluated physiological strain in electrical utilities workers during consecutive work shifts in hot outdoor conditions.

Methods: Four highly experienced electrical utilities workers were monitored during regularly scheduled work performed in hot conditions (～34°C) on two consecutive days. Worker hydration (urine specific gravity) was assessed prior to and following work. The level of physical exertion was determined by video analysis. Body core temperature (T_core) and heart rate (HR; presented as a percentage of maximum, %HR_max) were monitored continuously. Responses were reported for each worker individually and as a group mean ± standard deviation.

Results: According to current guidelines, all workers were dehydrated prior to work on both days (urine specific gravity: day 1, 1.025 ± 0.005; day 2, 1.029 ± 0.004) and remained dehydrated following work (urine specific gravity: day 1, 1.027 ± 0.015; day 2, 1.032 ± 0.004) except for one worker on day 1 (urine specific gravity of 1.005). On day 1, the proportion of the work shift spent at rest (as defined by the American Conference for Governmental and Industrial Hygienists, ACGIH) was 51 ± 15% (range: 30–64%). Time spent resting increased in all workers on the second day reaching 66 ± 5% (range: 60–71%) of the work shift. Work shift average T_core was 37.6 ± 0.1°C (range: 37.5–37.7°C) and 37.7 ± 0.2°C (range: 37.5–37.9°C) on days 1 and 2, respectively. Peak T_core surpassed the ACGIH recommended threshold limit of 38.0°C for work in the heat in three workers on day 1 (38.1 ± 0.2°C, range: 37.8–38.2°C) while all workers exceeded this threshold on day 2 (38.4 ± 0.2°C, range: 38.2–38.7°C). By contrast, work shift average (day 1, 67 ± 7%HR_max, range: 59–74%HR_max; day 2, 65 ± 4%HR_max, range: 60–70%HR_max) and peak (day 1, 90 ± 6%HR_max, range: 83–98%HR_max; day 2, 87 ± 10%HR_max, range: 73–97%HR_max) HR were similar between days.

Conclusion: This case report demonstrates elevations in thermal strain over consecutive work shifts despite decreases in work effort in electrical utilities workers during regular work in the heat.     

Changes in alpha-and beta-amylase activities during seed germination of African finger millet

Changes in α - and β -amylase activities in African finger millet (Eleusine coracana (L) Gaertener) were followed during germination. Germination on a small scale was performed at 15°C for 1-10 days and at 20, 25 and 30°C for 1-8 days. _α- and _β-Amylase activities in malt crude extracts of germinated finger millet were evaluated spectrophotometrically using chromogenic methods. The highest _α-amylase activity was exhibited in malt flour of finger millet germinated at 15°C for 9 days and at 20°C for 6 days, while the highest _β-amylase activity was displayed in the malt flour germinated for 5 days at 30°C. Thermo-stability of these enzymes in malt extracts was also evaluated. Malt extracts incubated at 40 and 50°C for up to 4 h retained about 84 and 64% of _α-amylase activities, respectively. There was a substantial decrease in _α-amylase activity to more than 90% when malt extracts were incubated at 70 and 90°C for 40 and 10 min, respectively. _β-Amylase was completely inactivated when the crude extract was incubated at 70°C for only 10 min. At pH 5.4, _α-amylase displayed maximum catalytic activity at around 45°C. Optimum temperature for _β-amylase activity at pH 6.0 was between 50 and 55°C. Activity staining for _α-amylase was also performed and three bands of activity were found in malt extract, each possibly representing an isozyme of _α-amylase from finger millet.     

Effects of postharvest storage and processing techniques on the main fatty acids in the profile of oil extracted from African Walnut (Tetracarpidium conophorum Mull. Arg.)

African Walnut (Tetracarpidium conophorum Mull. Arg.) is a perennial climber which grows in the western and central regions of Africa. The nuts are processed by boiling and roasting and are sold within 1–5 days to consumers through the open market system. During processing, storage and distribution, the nuts are typically exposed to high temperatures raising concerns over nutrient quality and safety. Although African walnut, like several other nuts, contains high amount of oil, there is no study reporting on how the common processing methods (boiling and roasting) affect the fatty acid profile. Nut samples (n = 702) at both early and late maturity were harvested and stored at 5 °C. Randomized sampling was done (0, 10 and 20 days) and nuts grouped according to treatments (boiling, roasting, unprocessed). Nuts were then held for 3 and 7 days at either 25 °C or 37 °C to simulate normal retail practices. Oil was extracted and analysed as fatty acid methyl esters using gas chromatography flame ionization detection and gas chromatography coupled mass spectrometry. Retention times were compared with known standards. Results indicated the presence of C16:0, C18:0, C18:1 cis-9, C18:2, cis-9, 12, C20:0, C18:3 with C18:3 being the most abundant (1.1–8.2 mg g⁻¹ dry matter). In general, postharvest storage at 25 °C or 37 °C for 3 or 7 days after boiling and roasting significantly increased concentrations of the fatty acids (>50%) in nuts stored for 10 days compared to unprocessed. Current processing methods and retail storage practices improved concentrations of the fatty acids in African walnut stored up to 10 days at 5 °C.     

Testing an egg yolk supplemented diet on boars to aid in sperm adaptation at 5°C

Abstract

In many species, extended semen can be stored at low temperatures to slow bacterial growth. However, boar semen performs poorly at temperatures below 15°C and this poses unique challenges, as it is not easy to maintain a constant 15–19°C during shipment. Some extenders have been formulated with egg yolk for storage at 5°C but the addition of egg yolk is not applicable in the majority of commercial operations. The purpose of this study was to evaluate if boar dietary supplementation with powdered egg yolk imparts any protective effects on sperm quality when stored at 15°C and 5°C for up to 11 days in a conventional extender. Ten boars were fed a commercial diet with the addition of 0.11Kg of powdered egg yolk for 10 weeks. Ejaculates collected on weeks 4, 6, 8, and 10 were processed for storage at both 15°C and 5°C and compared with ejaculates from boars fed a standard diet. Throughout an 11-day storage period, sperm quality was assessed including several motility and morphologic parameters and select plasma membrane properties (fluidity, integrity, and triacylglycerol content). Linear regression models were used to describe effects of treatment, storage day, week and temperature on all sperm parameters. Overall, there were minimal beneficial effects of egg yolk treatment on sperm quality parameters. Sperm from egg yolk supplemented boars did have a slower decline in viability and plasma membrane fluidity than that observed in the control sperm when stored at 5°C (p?<?0.001). Additionally, there was an increase in total morphologic abnormalities in sperm from egg yolk fed boars compared to controls at week 10 (p?<?0.001). In conclusion, the results of this study do not support a significant benefit to sperm quality or resistance to cold storage when feeding a 10-week dietary supplementation of 0.11Kg powdered egg yolk to crossbred boars.     

The hydrolysis and photolysis rates of nitrapyrin in dilute aqueous solution

The hydrolysis rate of nitrapyrin (2-chloro-6-(trichloromethyl)pyridine), the active ingredient of N-SERVE® nitrogen stabilizer (a registered trademark of The Dow Chemical Company, Midland, Michigan), in buffered, distilled water followed simple first-order kinetics over the concentration range, 6.2×10^?7 to 8.7×10^?5 M. The only product of the reaction was 6-chloropicolinic acid. The rate of the reaction decreased with increasing buffer concentration at 35°C (M buffer concentration-half-life): 0.005M ? 1.7 days, 0.02M?2.0 days, 0.067M?4.0 days. The ramifications of this negative salt effect are discussed. The hydrolysis rate was independent of pH over the range, 3.2 to 8.4. Additional data were obtained for rates at 25° and 45°C. The activation energy for the reaction under these conditions was 25.0 kcal/mole. Photolysis of nitrapyrin at 25°C in 0.005M phosphate buffers at pH 5.1, 7.1, 8.0, and in a natural water also followed simple first-order kinetics over the nitrapyrin concentration range, 7.1×10?6 to 7.5×10?6M. Again, there was no observable pH effect on the rate over the pH range investigated, nor was there a rate enhancement in the natural water. The half-life of the reaction under these conditions was 0.5 day. The products of this reaction were 6-chloropicolinic acid (6-C1PA), 6-hydroxypicolinic acid (6-OHPA), and unidentified polar material formed in that order in a series of sequential reactions. Simulation of the set of sequential reactions using determined first-order rate constants at 25°C and a starting concentration of 1.7 ppm predicts that nitrapyrin will be half gone in 0.5 day, that the concentration of 6-ClPA will peak at 1.3 ppm in 1.8 days, and that the concentration of 6-OHPA will peak at 0.2 ppm in 3.7 days.     

Effect of environmental temperature on the interactive developmental toxicity of radiofrequency radiation and 2-methoxyethanol in rats

Objective: This research was conducted to determine if altered environmental temperatures would affect the interactive developmental toxicity of radiofrequency (RF) radiation and the industrial solvent, 2-methoxyethanol (2ME). This is important because RF radiation is used in a variety of workplaces that have poorly controlled environmental temperatures, and many workers are concurrently exposed to various chemicals. Furthermore, we have previously demonstrated that combined exposure to RF radiation (10 MHz) and 2ME produces enhanced teratogenicity in rats. Methods: RF radiation sufficient to maintain colonic temperatures at the control value (38°), 39.0° or 40.0 °C for 2 or 4 h combined with either 0 or 100 mg/kg 2ME at environmental temperatures of 18°, 24° and 30 °C (65°, 75°, and 85 °F) were given on gestation day 13 to Sprague-Dawley rats. Dams were killed on gestation day 20, and the fetuses were examined for external malformations. Results and conclusions: Environmental temperature does affect the specific absorption rate (SAR) necessary to maintain a specific colonic temperature but does not affect the interactive developmental toxicity of RF radiation and 2ME in rats. These results, consistent with the literature, add to the evidence that the developmental toxicity of RF radiation (combined or alone) is associated with colonic temperature, not with SAR. Received: 17 September 1997 / Accepted: 13 February 1998     

A modified vitrification method reduces spindle and chromosome abnormalities

Development of an effective system for oocyte-cryopreservation is of clinical relevance in reproductive medicine. However, oocyte-preservation is not as effective as embryo preservation. In this study, we used a 37°C pre-equilibrium temperature as part of a modified vitrification method for human oocyte cryopreservation. The effect of the new method on spindle configuration, chromosomal arrangement, and mitochondrial distribution was investigated in in vitro-matured human oocytes. A total of 101 in vitro-matured oocytes were randomly assigned for vitrification at pre-equilibrium temperature of 37°C (37°C Group, n=50) or at room temperature (RT Group, 22-24°C, n=51). The time needed for vitrification in the 37°C group was significantly shorter than that in the RT group. Defective spindles were found in 45.5% and 69.0% oocytes in the 37°C group and RT group, respectively (p < 0.05). Abnormal chromosomes were found in 47.7% and 71.4% oocytes, respectively (p < 0.05). There were no significant differences with respect to oocyte survival rate and mitochondrial distribution pattern between the two groups. These results indicate that vitrification at a pre-equilibrium temperature of 37°C may reduce the incidence of defective spindle configuration and chromosomal abnormalities in in-vitro-matured human oocytes.

Abbreviations: ICSI: intracytoplasmic sperm injection; FSH: follicle-stimulating hormone; MII: metaphase II; EG: ethylene glycol; PROH: 1,2-propanediol     

Challenges of cold chain quality for routine EPI in south-west Burkina-Faso: An assessment using automated temperature recording devices

BackgroundAbnormal temperatures are a major issue for vaccines within the Expanded Program of Immunization in tropical climates. Prolonged exposure to temperatures outside the standard +2 °C/+8 °C range can impact vaccine potency.MethodsThe current study used automatic temperature recording devices (Testostore 171-1©) to monitor cold chain in remote areas of Western Burkina Faso. A series of 25 randomly selected health centers representing 33% of the existing 176 EPI facilities in Western Burkina Faso were prospectively assessed for eight months in 2015. Automatic measurements were compared to routine temperature loggers and vaccine vial monitors (VVM).ResultsThe median age for all refrigerators was 9 years with 10/25 (42%) older than 10 years. Adverse temperatures were recorded in 20/24 (83%) refrigerators and ranged from −18.5 °C to +34.2 °C with 12,958/128,905 (10%) abnormal hourly records below +2 °C and 7357/128,905 (5.7%) above +8 °C. Time of day significantly affected the rate of temperature excursions, with higher rates from 00 am to 06 am (p < 0.001) for low temperatures and 10–12 am (p < 0.001) and 13–16 pm (p < 0.001) for high temperatures. Abnormal temperatures lasted from 1 h to 24 h below +2 °C and 13–24 h above +8 °C. Standard manual registers reported only 182/2761 (7%) inadequate temperatures and VVM color change detected only 133/2465 (5%) disruptions. Reliability of the refrigerators ranged from 48% to 98.7% with a median of 70%. Risk factors for excursions were old age of the refrigerators, the months of April and May, hours of high activity during the day, and health staff-associated factors such as inappropriate actions or insufficient knowledge.ConclusionImportant cold chain reliability issues reported in the current study in Western Burkina Faso raise concern about vaccine potency. In the absence of systematic renewal of the cold chain infrastructure or improved staff training and monitoring, antibody response assessment is recommended to study levels of effective immunization coverage.     

The influence of above-optimal constant temperatures on South African Biomphalaria pfeifferi (Krauss) (Mollusca: Planorbidae)

The effects of constant above-optimal temperatures on the hatching, growth, survival, fecundity and development of the ovotestis of Biomphalaria pfeifferi from Komatipoort, South Africa, have been studied and compared with observations reported on B. glabrata. While rates of gametogenesis at 25 °C and ambient temperature (mean 22.8 °C) were similar, they were slightly accelerated at 27 °C. Fecundity and survival at 27 °C were considerably reduced and at 29 °C hyperthermia was pronounced.     

Growth of micro-organisms in all-in-one TPN-admixtures containing lipids

Growth properties of selected micro-organisms in standard total parenteral nutrition (TPN) admixtures containing carbohydrates, amino-acids, lipids, electrolytes and trace elements were studied. Three Gram-positive bacteria, seven Gram-negative bacteria and one yeast were included in the studies. The Gram-positive bacteria did not multiply in TPN-admixtures at 22°C or at 6°C. The Gram-negative bacteria did not multiply at 6°C (except S. marcescens and the psychrophilic bacterium F. marinotyphicum). At 22°C the Gram-negative bacteria (apart from A. calcoaceticus and P. aeruginosa), multiplied rapidly. The most rapidly growing bacterium was K. pneumoniae, which multiplied by more than four logs in 5 h at 22°C. The yeast, C. albicans, grew moderately in the TPN-admixtures at 22°C.     

The hydrolysis rate of chlorpyrifos,O-O-diethylO-(3,5,6-trichloro-2-pyridyl) phosphorothioate,and its dimethyl analog,chlorpyrifos-methyl,in dilute aqueous solution

The hydrolysis rate of chlorpyrifos (the active ingredient of DURSBAN® and LORSBAN® insecticides, registered trademarks of The Dow Chemical Company, Midland, Michigan) in water followed simple first-order kinetics over the concentration range, 3×10^?9 to 3×10^?7 M. In buffered distilled water at 25°C and pH 8.1, 6.9, and 4.7, the half-life was 22.8, 35.3, and 62.7 days, respectively. Additional data were obtained for rates at 15° and 35°C. The activation energy for the reaction under these conditions was 21.2 kcal/mole. A 16-fold rate enhancement was demonstrated in canal and pond water at 25°C. Likewise, there was a catalytic effect on the hydrolysis rate in the presence of copper (II) ion. The same information was generated for chlorpyrifos-methyl, the dimethyl analog of chlorpyrifos. In this case, the corresponding half-life values for hydrolysis at 25°C and pH 7.8, 6.7, and 4.2 were 12.7, 17.4, and 22.8 days, respectively. The activation energy was 20.8 kcal/mole, not significantly different from that for chlorpyrifos. A hydrolysis rate enhancement also occurred for chlorpyrifos-methyl in canal water. Qualitatively, the products of chlorpyrifos hydrolysis were 3,5,6-trichloro-2-pyridinol (I),O-ethylO-hydrogenO-(3,5,6-trichloro-2-pyridyl) phosphorothioate (II), andO, O-dihydrogenO-(3,5,6-trichloro-2-pyridyl) phosphorothioate (III). In the case of chlorpyrifos-methyl, the hydrolysis products were compound I and the methyl analog of compound II.