An excitatory amino acid(s) in the ventrolateral medulla is (are) required for breathing to occur in the anesthetized cat.

The purpose of the present study was to identify sites(s) in the ventrolateral medulla where excitatory amino acids are involved in respiratory control. For this purpose, the respiratory effects produced by bilateral microinjection of excitatory amino acid antagonist drugs were examined while tidal volume (Vt), respiratory rate (f), arterial blood pressure and heart rate were monitored in chloralose-anesthetized cats. Microinjection of kynurenic acid (12.5 nmol) into a site approximately 3 mm rostral to obex, 4 mm lateral to midline and 1.5 mm below the ventral surface produced a decrease in Vt (-20 +/- 2 ml), an increase in f (+20 +/- 3 breaths/min) and a decrease in respiratory minute volume (-108 +/- 19 ml/min) (n = 8). These changes progressed to apnea in each animal tested. No significant changes in blood pressure or heart rate were observed. To determine the excitatory amino acid receptor subtype(s) involved, antagonists of n-methyl-D-aspartate (NMDA) (3-[(RS)-carboxypiperazin-4-yl]-propyl-1-phosphoric acid (CPP] and non-NMDA [6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)] receptors were microinjected bilaterally into this site. In the case of CPP, three doses were studied (0.25 nmol, n = 4; 0.75 nmol, n = 3; 2.25 nmol, n = 2). All three doses produced similar decreases in Vt (-12 +/- 1, P less than .05; -10 +/- 1, P less than .05; and -16 +/- 5 ml, respectively) and increases in f (+14 +/- 2, P less than .05; +10 +/- 3, P less than .05; and +12 +/- 3 breaths/min, respectively). None of these animals exhibited apnea.(ABSTRACT TRUNCATED AT 250 WORDS)     

Closed suction wound drainage and lower-segment caesarean section

Summary. In a randomized controlled study of wound suction drainage after transverse suprapubic incision for lower-segment caesarean section no significant advantages could be demonstrated for routine drainage in terms of wound infection, haematoma formation, duration of hospital stay or analgesic requirements.     

SELECTIVE ENDOSCOPY IN MANAGEMENT OF INGESTED FOREIGN BODIES OF THE UPPER GASTROINTESTINAL TRACT: IS IT SAFE?

During a four-year period, 308 patients presented following ingestion of foreign bodies. Ingestion was accidental in 272 cases (88.3%) and deliberate in the remainder. Symptoms at presentation included dysphagia, odynophagia, nausea and vomiting, chest pain and pharyngeal discomfort. Sixty-eight patients were asymptomatic. A policy of expectant management and selective endoscopy was employed. Following initial assessment 202 patients (65.6%) were discharged without treatment, 30 (9.7%) of whom were later reviewed as outpatients and did not require admission. Forty-nine patients (16%) were admitted for treatment; 27 had oesophagoscopy, five bronchoscopy and two had foreign body extraction with direct laryngoscopy. In nine patients who were endoscoped, no foreign body was identified. Twenty-seven others were referred to the otorhinolaryngology service in another hospital. There were no deaths in the group and morbidity was 1.2%. We conclude that a policy of selective endoscopy is safe and effective in the management of patients following ingestion of foreign bodies.     

Synovial fluid pyrophosphate and nucleoside triphosphate pyrophosphatase: comparison between normal and diseased and between inflamed and non-inflamed joints.

Deposition of intra-articular calcium pyrophosphate is associated with both aging and arthropathy; increased concentrations of free pyrophosphate (PPi) may contribute to such deposition. Free pyrophosphate and nucleoside triphosphate pyrophosphatase (NTPase) were estimated in synovial fluids from 50 subjects with normal knees and from 44 patients with rheumatoid arthritis, 61 with pyrophosphate arthropathy, and 59 with osteoarthritis. For arthropathic knees clinically assessed inflammation was classified as active or inactive using a summated score of six clinical features. The order of PPi (mumol/l) and NTPase (mumol PPi/30 min/mg protein) was pyrophosphate arthropathy greater than osteoarthritis greater than rheumatoid arthritis (median PPi, NTPase respectively: for pyrophosphate arthropathy 15.9, 0.45; for osteoarthritis 9.3, 0.25; for rheumatoid arthritis 4.4, 0.18), with significant differences between all groups. In pyrophosphate arthropathy both PPi (mumol/l) and NTPase (mumol PPi/30 min/mg protein) were higher than normal (15.9, 0.45 v 8.6, 0.2 respectively), but findings in osteoarthritis did not differ from normal. The inflammatory state of the knee had a distinct but variable effect on synovial fluid findings in rheumatoid arthritis and pyrophosphate arthropathy, but not in osteoarthritis. There was no correlation of either PPi or NTPase with age, or between PPi and NTPase in any group. This study provides in vivo data for synovial fluid PPi and NTPase. It suggests that factors other than PPi need to be considered in a study of crystal associated arthropathy. Clinical inflammation, as well as diagnosis, is important in synovial fluid studies.