Cochrane Db Syst Rev
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Cochrane Db Syst Rev · Jan 2003
ReviewIntra-cytoplasmic sperm injection versus conventional techniques for oocyte insemination during in vitro fertilisation in patients with non-male subfertility.
In vitro fertilisation (IVF) as treatment for male factor subfertility is associated with lower fertilisation and pregnancy rates than for other indications. Since the late 1980s several assisted fertilisation techniques have emerged and have been rapidly developed to try to enhance results for couples with male factor subfertility, or to help couples with severe male factor for whom conventional IVF was not possible. The techniques of partial zona dissection (PZD) and of subzonal microinjection of spermatozoa into the perivitelline space (SUZI) are by far surpassed by the technique of intra-cytoplasmatic sperm injection (ICSI). ICSI has proven to be the therapy of choice for couples with severe male factor subfertility. ⋯ Whether ICSI should be preferred to IVF for cases of non-male factor subfertility remains an open question. Further research should report livebirth rates and adverse events.
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Some studies have suggested a protective effect of antioxidant nutrients on lung cancer. Observational epidemiological studies suggest an association between higher dietary levels of fruits and vegetables containing beta carotene and a lower risk of lung cancer. ⋯ There is currently no evidence to support recommending vitamins such as alpha-tocopherol, beta-carotene or retinol, alone or in combination, to prevent lung cancer. A harmful effect was found for beta-carotene with retinol at pharmacological doses in people with risk factors for lung cancer (smoking and/or occupational exposure to asbestos). More research from larger trials and with longer follow-up is needed to analyse the effectiveness of other supplements.
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Cochrane Db Syst Rev · Jan 2003
Review Meta AnalysisPet allergen control measures for allergic asthma in children and adults.
Although pet removal has been recommended in guidelines on the management of allergic asthma, pet ownership remains high in families where one or more members have an allergy to pet dander. Allergen control measures such as air filtration units placed in the homes of pet-allergic asthmatics have been used as a means of reducing allergen exposure. ⋯ The available trials are too small to provide evidence for or against the use of airfiltration units to reduce allergen levels in the management of pet-allergic asthma. Adequately powered trials are needed. There are no trials of other allergen reduction measures, such as pet washing or possibly pet removal.
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Cochrane Db Syst Rev · Jan 2003
ReviewContinuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children.
Acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in the pediatric age group. Despite varied etiologies and different population characteristics the aims of therapy are to achieve adequate oxygenation and ventilation. Positive pressure ventilation is currently the standard of care. It is ordinarily provided by intubation and mechanical ventilation, which is associated with a number of well recognized complications. Continuous negative extrathoracic pressure ventilation (CNEP) or continuous positive airway pressure ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies. In a systematic review of studies involving neonates, continuous distending pressure using either CNEP or CPAP (applied via face mask) was associated with reduction in mortality but with an increased incidence of pneumothoraces, in neonates. ⋯ There is a lack of well designed, large controlled experiments comparing use of noninvasive modes of respiratory support in children with AHRF. Uncontrolled evidence of reduction in the intubation and hospital stay needs confirmation in proper studies evaluating risks involved with these practices. Implication for research: It is unlikely that CNEP or Ni-CPAP will have significant impact on mortality in AHRF, however, even a small reduction may be very important. Studies assessing other outcomes such as avoidance of intubation and its associated complications, reduction in hospital stay and improvement in patient comfort are also valuable in assessing the overall impact of these strategies.
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Cochrane Db Syst Rev · Jan 2003
ReviewEffect(s) of assisted hatching on assisted conception (IVF & ICSI).
Failure of implantation and thus conception might result from inability of the blastocyst to escape from its zona pellucida. Artificial disruption of this coat has been proposed as a method of improving the success of assisted conception. ⋯ There is insufficient evidence to determine any effect of AH on the 'take-home-baby rate' of assisted conception. There are also very few data regarding miscarriage rates and other adverse events. This prevents us from extrapolating the impact of AH on live births from our finding of improved odds of clinical pregnancy.