Fertilization and pregnancy using intentionally cryopreserved testicular tissue as the sperm source for intracytoplasmic sperm injection in 10 men with non-obstructive azoospermia

Testicular tissue extraction (TESE) to obtain spermatozoa for use with intracytoplasmic sperm injection (ICSI) has recently been employed in patients with non-obstructive azoospermia. Standard protocol is to retrieve a new sample of testis tissue on the day of oocyte recovery. Unfortunately, approximately 30% of men will possess no spermatozoa in their tissue, making ICSI an impossibility. We investigated whether testicular tissue that was intentionally obtained well before any planned ICSI cycle and cryopreserved could then serve as an efficacious sperm source in a subsequent ICSI cycle. This study reports on 10 men with non-obstructive azoospermia who did have spermatozoa found within their testis tissue at the time of TESE and who chose to use their frozen samples as the source of spermatozoa for a later cycle of ICSI. In 19 cycles the overall fertilization rate was 48%. Embryo transfer occurred in 89% of cycles. Two couples have achieved pregnancy (one ongoing, one delivered). All patients except one had multiple vials of frozen tissue remaining following their first cycle. This approach is offered as an alternative to repeated testicular tissue sampling, as the availability of spermatozoa is assured prior to the initiation of ovulation induction. This tissue can be harvested at the same time as diagnostic biopsy, thereby minimizing the number of surgical procedures.

Trial of a "credit card" asthma self-management plan in a high-risk group of patients with asthma

BACKGROUND

The "credit card" asthma self-management plan provides the adult asthmatic patient with simple guidelines for the self-management of asthma, which are based on the self-assessment of peak expiratory flow rate recordings and symptoms.

OBJECTIVE

The study was a trial of the clinical efficacy of the credit card plan in a high-risk group of asthmatic patients.

METHODS

In this "before-and-after" trial, patients discharged from the emergency department of Wellington Hospital, after treatment for severe asthma were invited to attend a series of hospital outpatient clinics at which the credit card plan was introduced. Questionnaires were used to compare markers of asthma morbidity, requirement for emergency medical care, and medication use during the 6-month period before and after intervention with the credit card plan.

RESULTS

Of the 30 patients with asthma who attended the first outpatient clinic, 26 (17 women and 9 men) completed the program. In these 26 participants, there was a reduction in both morbidity and requirement for acute medical services: specifically, the proportion waking with asthma more than once a week decreased from 65% to 23% (p = 0.005) and the proportion visiting the emergency department for treatment of severe asthma decreased from 58% to 15% (p = 0.004). The patients attending the clinics commented favorably on the plan, in particular on its usefulness as an educational tool for monitoring and treating their asthma.

CONCLUSIONS

Although the interpretation of this study is limited by the lack of a randomized control group, the findings are consistent with other evidence that the credit card asthma self-management plan can be an effective and acceptable system for improving asthma care in a high-risk group of adult patients with asthma.

Partial vs full beta-receptor agonism. A clinical study of inhaled albuterol and fenoterol

STUDY OBJECTIVE

To compare the maximal extrapulmonary effects of the beta-agonists albuterol and fenoterol in eight healthy volunteers.

SUBJECTS AND METHODS

In this double-blind study, we have examined the maximum cardiac effects (electromechanical systole [QS2I]--a measure of inotropy, heart rate, BP) and metabolic effects (plasma K+ and cyclic adenosine monophosphate [cAMP]) of repeated inhalation of albuternol and fenoterol. In eight healthy volunteers, 400 microg of each drug was administered every 10 min until QS2I and plasma K+ had reached a plateau (+/- 0.1 mmo l/L for K+, and +/- 10 ms for QS2I). The maximum response (Emax) and the dose of albuterol required to produce 50% of the maximum response to fenoterol (ED50F) were calculated.

RESULTS

The Emax for fenoterol was significantly greater than albuterol for plasma K+ (-1.4 vs -1.03 mmol/L; p<0.002), QS2I (-71.8 vs 57.5 ms; p=0.047), and cAMP (33.8 vs 18.1 nmol/L; p<0.002). The dose required to produce the ED50f was significantly greater for albuterol than for fenoterol with potency ratios of 1.75, 1.61, and 2.26 for plasma K+, QS2I, and cAMP, respectively. There were no significant differences between fenoterol and albuterol with respect to heart rate (Emax, 44.9 vs 32.5 beats/min; p=0.19; potency ratio, 1.98; p=0.052).

CONCLUSIONS

These findings suggest that albuterol behaves as a partial agonist at beta-receptors when compared with fenoterol, and that when inhaled in doses currently recommended for severe asthma, albuterol will result in lesser maximum cardiac and metabolic effects than fenoterol. These findings are consistent with the hypothesis that the property of full receptor agonism may contribute to the increased risk of death associated with fenoterol.

A pilot study to investigate the pulmonary effects of digoxin in patients with asthma

AIM

A number of studies have shown that increased salt intake is associated with worsening asthma. The aim of this study was to investigate the respiratory effects of digoxin (a potent inhibitor of Na+K+ATPase) in patients with asthma.

METHODS

Eight asthmatic patients were given digoxin (0.5 mg/daily) or matching placebo for 8 days. Treatments were assigned using a randomised double blind, crossover design. Bronchial hyperresponsiveness to methacholine, forced expiratory volume is one second (FEV1, serum potassium (K), urinary sodium and K, heart rate, blood pressure and the QTc interval of the ECG were measured on each treatment.

RESULTS

When compared to placebo, digoxin significantly decreased FEV1 (p<0.03); the QTc interval (p<0.05), and increased serum K (p<0.02). There was a tendency for digoxin to increase bronchial hyperresponsiveness.

CONCLUSION

In this small study digoxin resulted in a decline in spirometry. Further studies in a larger group of patients should be performed to assess this potentially adverse effect of digoxin.

Withdrawal of fenoterol and the end of the New Zealand asthma mortality epidemic

In response to the evidence that fenoterol was a major cause for the second epidemic of asthma deaths in New Zealand, the Department of Health severely restricted its availability, thereby allowing an 'experiment in prevention' to be undertaken. These regulatory actions, which effectively removed fenoterol from the market in New Zealand, were associated with a sudden and marked reduction in asthma mortality, providing further evidence for a causative role of fenoterol in the epidemic of asthma deaths in New Zealand.

End of the New Zealand asthma mortality epidemic

In 1989, a case-control study reported that inhaled fenoterol was associated with the epidemic of asthma deaths that had affected New Zealand since 1976. The New Zealand Department of Health issued warnings about the safety of fenoterol and restricted its availability. The associated time trends are consistent with the hypothesis that fenoterol was the main factor in the New Zealand asthma mortality epidemic. The epidemic commenced when fenoterol was introduced in 1976, and the New Zealand death rate remained the highest in the world for more than a decade. After publication of the case-control study, the death rate fell by half and has now remained low for a further 3 years (1990-92). Time-trend data do not suggest a class effect of inhaled beta-agonists in the epidemic: there was no association between beta-agonist sales and the start of the epidemic, and total sales of inhaled beta-agonists actually increased slightly during 1989-90 when the epidemic came to an end. Time-trend data are also inconsistent with the hypothesis that the epidemic may have occurred because of underprescribing of inhaled corticosteroids. Similarly, time-trend data is incosistent with hypotheses postulating a major role of social factors such as unemployment. Data on time trends should be assessed with caution, because time trends in asthma deaths can be affected by many factors. Nevertheless, the New Zealand time trends are consistent with fenoterol being the main cause of the New Zealand asthma mortality epidemic and are inconsistent with a significant role for other suggested causes.

The effects of sympathomimetics on the cardiovascular system of sheep

1. Sheep hearts have been used to study the effects of beta-adrenoceptor (beta-AR) agonists in order to better understand the effects of common asthma treatment drugs on heart rate, cardiac power output and cardiac pathology. Hearts have been examined both in vivo and in vitro. 2. In whole anaesthetized sheep, isoprenaline, fenoterol and salbutamol induced dose-dependent increases in heart rate. Hypokalaemia in response to salbutamol was accentuated in hypoxia. Many of these hearts showed significant myocardial lesions. Hypoxia alone caused no significant cardiac response. 3. As expected, the beta 1-AR agonist dobutamine caused dose-dependent increases in heart performance (heart rate and cardiac power output). Both responses were blocked by metoprolol and propranolol. The beta 2-AR agonist salbutamol caused dose-dependent increases in heart rate and although cardiac output increased, cardiac power output remained unchanged as a consequence of the fall in peripheral resistance. The heart rate changes were blocked by metoprolol. Importantly, propranolol blocked both the heart rate response and the fall in peripheral resistance. 4. Isolated atrial strips showed a right shift of their dose-response curve to isoprenaline in the presence of the highly selective beta 2-AR antagonist ICI 118,551 at concentrations above 1 x 10(-8) mol/L. 5. We conclude that the sheep heart shows many pharmacological characteristics of the human heart which makes it a good pharmacological model in addition to its being amenable to many common techniques available for humans.