OlinInfo, September 2009

Newsletter of the Franklin W. Olin Library at Rollins Colleg

Impact of Caesarean section on subsequent fertility: a systematic review and meta-analysis.

STUDY QUESTION: Is there an association between a Caesarean section and subsequent fertility? SUMMARY ANSWER: Most studies report that fertility is reduced after Caesarean section compared with vaginal delivery. However, studies with a more robust design show smaller effects and it is uncertain whether the association is causal. WHAT IS KNOWN ALREADY: A previous systematic review published in 1996 summarizing six studies including 85 728 women suggested that Caesarean section reduces subsequent fertility. The included studies suffer from severe methodological limitations. STUDY DESIGN, SIZE, DURATION: Systematic review and meta-analysis of cohort studies comparing subsequent reproductive outcomes of women who had a Caesarean section with those who delivered vaginally. PARTICIPANTS/MATERIALS, SETTING, METHODS: Searches of Cochrane Library, Medline, Embase, CINAHL Plus and Maternity and Infant Care databases were conducted in December 2011 to identify randomized and non-randomized studies that compared the subsequent fertility outcomes after a Caesarean section and after a vaginal delivery. Eighteen cohort studies including 591 850 women matched the inclusion criteria. Risk of bias was assessed by the Newcastle-Ottawa scale (NOS). Data extraction was done independently by two reviewers. The meta-analysis was based on a random-effects model. Subgroup analyses were performed to assess whether the estimated effect was influenced by parity, risk adjustment, maternal choice, cohort period, and study quality and size. MAIN RESULTS AND THE ROLE OF CHANCE: The impact of Caesarean section on subsequent pregnancies could be analysed in 10 studies and on subsequent births in 16 studies. A meta-analysis suggests that patients who had undergone a Caesarean section had a 9% lower subsequent pregnancy rate [risk ratio (RR) 0.91, 95% confidence interval (CI) (0.87, 0.95)] and 11% lower birth rate [RR 0.89, 95% CI (0.87, 0.92)], compared with patients who had delivered vaginally. Studies that controlled for maternal age or specifically analysed primary elective Caesarean section for breech delivery, and those that were least prone to bias according to the NOS reported smaller effects. LIMITATIONS, REASONS FOR CAUTION: There is significant variation in the design and methods of included studies. Residual bias in the adjusted results is likely as no study was able to control for a number of important maternal characteristics, such as a history of infertility or maternal obesity. WIDER IMPLICATIONS OF THE FINDINGS: Further research is needed to reduce the impact of selection bias by indication through creating more comparable patient groups and applying risk adjustment

The effect of Pomegranate Peels Aqueous Extract against Streptococcus Mutans and the Adherence to tooth surface in Comparison to Chlorhexidine Gluconate (in Vitro Study)

For centuries, nature has been an enormous source of agents of medical importance and this study was conducted to evaluate the antibacterial activity of aqueous extract of pomegranate peels against Streptococcus mutans by using agar diffusion technique and the adherence to tooth surface in comparison to chlorhexidine gluconate in vitro was also studied. This study revealed that pomegranate peels exhibit good antibacterial activity and this activity was found to be increased as the concentration of extract increased and the result also showed that the pomegranate peels aqueous extract was effective in inhibiting the adherence of Streptococcus mutans to tooth surface Keywords: pomegranate peels, streptococcus mutans, adherenc

Maintaining Seed Quality of Maize and Wheat through Dry Chain Technology in Pakistan

Seed is inevitably deteriorated during storage and higher seed moisture content is the primary cause of this decline in seed quality. Dry Chain is a valuable tool, by using moisture proof hermetic containers to preserve seed quality throughout supply chain. This study evaluated and compared the performance of wheat and maize seed in different hermetic storage packaging (Super bag, Anaaji bag and drum) with conventionally used woven polypropylene bags after six months storage in ambient conditions. Seed moisture content was increased up to 11.53 and 13.55% in wheat and maize respectively when packed in polypropylene bags while it remained low (approximately 10 and 11.4% in wheat and maize respectively) when packed in hermetically sealed bags and drum. Germination was maintained in both cereal seeds stored in hermetically sealed Super bag, anaaji bag and drum while it reduced in polypropylene bags as compared to initial seed quality. Seed stored in polypropylene bag deteriorated quickly, which resulted in loss of seed vigour as indicated by higher malondialdehyde contents and electrical conductivity of seed leachates. It can be concluded that maintenance of seed dryness with hermetic storage is useful in preservation of seed quality and related attributes under high relative humidity environment

Identification of thalassemia disorder using active contour

Thalassemia was known as the red blood cell (RBC) morphology disorder. This disease mostly affects the shape of the red blood cells. Thalassemia becomes the major public health problem when one of the people becomes the carrier of the disease. It can occur within a months after birth or even before birth and results in inappropriate growth and development of babies. Sometimes the affected babies will die shortly after birth. In order to screen thalassemia, there are a few tests need to be done. Firstly by performed Complete Blood Count (CBC) and secondly continued with hemoglobin electrophoresis test. This CBC test will identify the morphology of RBC. Hence, this paper will discuss the methods on identifying the morphology of thalassemia blood cells by using active contour technique. From the result of 16 normal and abnormal blood cell images, the active countour methods able to identifyThalassemia blood cells with accuracy of 90% from the abnormal cell images

Plasmid DNA Analysis of Pasteurella multocida Serotype B isolated from Haemorrhagic Septicaemia outbreaks in Malaysia

A total of 150 purified isolates of Pasteurella multocida serotype B were used (Salmah, 2004) for plasmid DNA curing experiment to determine hyaluronidase activity, antibiotic resistance pattern (ARP) and mice lethality test (LD50) for their role of pathogenicity. A plasmid curing experiment was carried out by using the intercalating agent; ethidium bromide and rifampicin, where it was found all the plasmids had been cured (plasmidless) from Pasteurella multocida. All of these plasmidless isolates maintained their phenotypic characteristics. They showed the same antibiotic resistancepattern as before curing, produced hyaluronidase and possessed lethality activity in mice when injected intraperitoneally(i.p). Based on this observation, the antibiotic resistance, hyaluronidase activity and mice virulence could probably be chromosomal-mediated. Plasmids were detected 100% in all P. multocida isolates with identical profile of 2 plasmids size 3.0 and 5.5 kb. No large plasmids could be detected in all isolates. Since all the isolates appeared to have identicalplasmid profiles, they were subjected to restriction enzyme(RE) analysis. From RE analysis results obtained, it can be concluded that the plasmid DNA in serotype B isolates are identical. Only 4 of 32 REs were found to cleave these plasmids with identical restriction fingerprints; BglII, HaeIII, RsaI and SspI. From RE analysis results, it can be concluded that the plasmid DNA isolates are identical. This plasmid might not played any role in pathogenicity of Pasteurella multocida serotype B, however this information is important for the construction of shuttle vectors in genetic studies of the pathogenicity of haemorrhagic septicaemia(HS)

Modification and Performance Evaluation of Active Solar Dryer for High Moisture Tomato Crop

In this study, two active solar cabinet dryers with capacity each to dry 10 kg of fresh vegetable were fabricated. The drying cabinet of the first dryer was fabricated using plywood and is refer to as unmodified dryer (UM) while the second dryer with white transparent glass and is refer to as modified dryer (MD). The performances of the two dryers in terms of total drying time, final moisture content obtained and preservation of nutritive values of the dried vegetable were investigated using tomato as sample. Ten kilogram of the sample were sliced to about 1cm and neatly arranged in the drying chamber for the drying process in a period of two days (8am-6pm). The results revealed that there was a reduction in total drying time of 2.5 hours, from 18 hours in UM to 15.5hours in MD which corresponds to reduction in moisture content (wet basis) from initial value of 92% to final moisture content of 12- 13.3%. The results further revealed that maximum drying rate of 6.9 kg/h was observed for UM dryer and 9.4 kg/h for MD both obtained within 8 hours of drying time.  The average temperature recorded in the MD was found more than the UM by about 13°C at 3.00pm. The efficiency of the MD in terms of reduction in total drying time was 13.89% higher than the UM. Proximate analysis result shows the composition of the dried tomato in the UM to be protein, 0.76%; lipids, 1.00%; vitamin E, 0.0083%; moisture content, 13.3%; ash, 0.60% and crude fiber, 1.80%. However, the composition of dried tomato in MD were protein, 0.69%; lipids, 0.90%; vitamin E, 0.0080%; moisture content, 12%; ash, 0.58% and crude fiber, 1.78%

Production and Economics Evaluation of Pilot Scale Essential Oil Extract from Eucalyptus Citriodora Leaves

In this study, essential oil was extracted from eucalyptus citriodora leaves plant species (lemon-scented gum) in a pilot plant using steam distillation technology. The extraction pattern of the oil was monitored over time and economic analysis of the production was carried out.  Five batches were carried out in a day and the results revealed that the daily production of the oil was 0.579 liters in a loading capacity of 100kg of leaves. It was also observed that the total production cycle per batch was 1.96 hours out of which 80 minutes were the actual extraction time with lag period of 37 minutes. The results further revealed that 66.7% of the oil was extracted in 40 minutes while 95.6% in 80 minutes. Liquefied petroleum gas (LPG) was used as source of energy with daily consumption of 7.5 kg at a cost of N2,400.00K. The economic analysis on annual basis revealed that the operating cost was N1,742,400.00K. The production output of the oil was estimated at 138.96 litres with expected selling price of N4,863,600.00K at the rate of N35,000.00K per litre and expected profit after tax of N2,115,871.00K. From this economic analysis carried out based on the practical data generated in the pilot plant, this project is highly profitable and is strongly recommended to potential investors and entrepreneurs. This will help in providing jobs for our teaming unemployed youths mostly in rural areas where these raw materials are in abundant thereby increasing nation’s foreign earning due to its export potential