Sniff nasal inspiratory pressure: what is the optimal number of sniffs?

Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.     

A clinical approach to the management of a patient with suspected renovascular disease who presents with leg ischemia.

Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases.     

Alteration of the α-tocopherol content in the brain and peripheral nervous tissue of dysmyelinating mutants

In the brain of quaking and shiverer mutants, vitamin E content was normal when related to both wet weight and dry weight. When related to lipid extract, phosphorus, and polyunsaturated fatty acids, vitamin E was slightly increased only in the quaking mutant. In the sciatic nerve from trembler mutants, vitamin E was 134% of control values in the dry material, but normal in relation to wet weight. It was 260% in the lipid extract and 716% based on phosphorus. In relation to total fatty acids, there was a threefold increase in trembler mutants. Interestingly, it was increased approximately three times when related to 18∶2 n?6, 20∶4 n?6, and 20∶5 n?3, and seven times when related to 22∶6 n?3. The fact that the amount of vitamin E in fresh weight was normal, suggests that vitamin E plays a role in some nonmembrane material, such as the extracellular matrix or the basal lamina.     

Comparison between ankle and toe index in patients with peripheral arterial disease

In contrast to the systolic blood pressure at the posterior tibial artery, the evaluation of pressure at the digital artery of the foot before and after exercise in patients with peripheral arterial disease is not well known. Twenty three patients with peripheral vascular disease were examined. The systolic pressure was measured by means of an ultrasound velocity detector at the brachial and posterior tibial artery. Digital artery pressure was determined with photoplethysmography. Pressures were measured before and within 5 and 10 minutes after a treadmill test. Ankle and toe index was calculated. At rest the toe index is lower than the ankle index and after a treadmill test the decrease in toe index occurs in parallel to the ankle index.     

A controlled study of oxygen metabolite release by alveolar macrophages from children with interstitial lung disease

The ability of alveolar macrophages (AM) to release O2 metabolites was studied in 8 children with interstitial lung disease (ILD), and in 11 children without lung parenchyma disorder. AM were collected by bronchoalveolar lavage. The experiments were performed on unstimulated AM and on AM stimulated by phorbol myristate acetate (PMA) or zymosan. Our results indicated that, with or without triggering agent, the amount of O2 metabolites release was a linear function pattern with time. The accumulation of superoxide anion (O2-) and hydrogen peroxide (H2O2) into the extracellular medium differed depending on the triggering agent used: with PMA, the amount of O2- released was threefold the amount of H2O2 detected in the medium, whereas with zymosan the O2- accumulation was tenfold higher than the amount of H2O2 measured. In patients with ILD, a significant increase in the amount of H2O2 release was observed for both unstimulated and stimulated AM (p less than 0.001). In this group, the measurement was repeated after a 2-month steroid treatment: prednisone had markedly improved the clinical, radiologic, and functional status of the patients, and this improvement was in good correlation with the decrease of O2 metabolite production. The amount of H2O2 release in each case was within the range of control values. Evaluation of O2 metabolite release by AM could be a useful parameter in the assessment of the activity of ILD.