Automated percutaneous lumbar discectomy (APLD) — Method and 1-Year follow-up

From July 1989 to June 1991 135 discs on 129 patients were treated, in about twothirds at level L4/5 and at the remaining one third L5/S1.15% (n = 2) failed technically. Sixty eight patients are in the 1-year follow-up. Average age was 41 years (range 16–68 years). Average pain duration was 12 months, and average aspiration time was 25.8 min (range 15–45 min). All patients had contained disc lesions, suffered from radicular symptoms and had not responded to conservative treatment. 67,1% (group A, n =45) had a failure rate of 17,8%. Patients with associated degenerations (group B, n = 7) had a failure rate of 35,3%. 80% of the patients with recurrent radicular symptoms (group C, interval patients, n = 6) were free of symptoms. Re herniation rate in all patients was 2.9%, and the laminectomy rate 4.4%. No major complications were noted. Treated disc level, patient aage, aspirated nucleus material and CT changes revealed no correlation to clinical success. Patients with associated degenerations (group B) as wellas those with longer pain duration and larger contained disc lesions had a significantly worse outcome. Correspondence to: C. Luft     

Raised levels of exhaled carbon monoxide are associated with an increased expression of heme oxygenase-1 in airway macrophages in asthma: a new marker of oxidative stress

BACKGROUND—Chronicinflammatory diseases are associated with an increased production ofoxidants. Induction of a stress protein, heme oxygenase (HO) HO-1, is acytoprotective mechanism against oxidative cellular injury. HO-1catabolises heme to bilirubin, free iron, and carbon monoxide (CO).
METHODS—Exhaled CO andsputum bilirubin levels were measured and HO-1 protein expression inairway macrophages was determined by Western blotting in asthmaticpatients as levels of oxidants are raised in asthma and may induceHO-1.
RESULTS—Exhaled CO wassignificantly increased in 37 non-steroid treated asthmatic patientscompared with 37 healthy subjects (5.8(95% CI 5.20 to 6.39) ppm vs2.9 (2.51 to 3.28) ppm; p<0.0001) but was similar to normal in 25 patients who received corticosteroids (3.3 (95% CI 2.92 to 3.67) ppm;p>0.05). In non-treated asthmatic patients more HO-1 protein wasexpressed in airway macrophages than in normal subjects. Bilirubinlevels in induced sputum were also higher than in normal subjects.Inhalation of hemin, a substrate for HO, significantly increasedexhaled CO from 3.8 (95% CI 2.80to 4.87) ppm to 6.7 (95% CI 4.95 to8.38 CI) ppm (p<0.05) with a concomitant decrease in exhaled nitricoxide levels, suggesting an interaction between the two systems.
CONCLUSIONS—Increasedexhaled CO levels and HO-1 expression may reflect induction of HO-1which may be inhibited by steroids. Measurement of exhaled CO, an indexof HO activity in non-smoking subjects, may therefore be clinicallyuseful in the detection and management of asthma and possibly otherchronic inflammatory lung disorders.

     

Age-related metabolic modifications in male F344 rats

Basal metabolic rate, basal colonic temperature, and response to intraperitoneal injection of tryamine were examined in three age groups: young (3 months), adult (12 months), and old (24 months) of male Fischer 344 rats. Basal metabolic rate of sedentary male F344 rats decreased significantly between 3 months (21.5 ml O2 X kg-1 X min-1) and 1 year (19.4 ml) of age and continued to decrease in the oldest animals (19.0 ml). The decrease between 1 and 2 years was not statistically significant. Basal colonic temperature showed a step-wise significant increase with age. Mean colonic temperature was 36.7 degrees C at 3 months, 37 degrees C at 1 year, and 37.5 degrees C at 2 years. Higher optimal doses of tyramine were required for 1- and 2-year-olds than for 3-month-olds. The optimal dose was 2 mg X kg-1 for 3-month-olds and 5 mg X kg-1 for 1- and 2-year-olds. Although the optimal dosages were the same for the 1- and 2-year-olds, 2-year-olds had lower peak response and the response was slower than for the 1-year-olds.     

Positive and negative symptoms in schizophrenia

Negative and positive symptoms were determined for 46 drug-free patients who met Research Diagnostic Criteria (RDC) and/or Feighner criteria for schizophrenia. A modified version of the Scale for the Assessment of Negative Symptoms (SANS) was completed for each patient based on items from the Schedule for Affective Disorders and Schizophrenia (SADS) and other scales. Positive symptoms were scored from the SADS as well as from the following four diagnostic systems: RDC, Schneider's first-rank symptoms, the 12-point Flexible system, and Langfeldt's criteria for poor prognosis schizophrenia. For all patients, there was no correlation of negative symptoms and positive symptoms defined by any diagnostic system. Within the paranoid and undifferentiated subtypes, there was a positive correlation of positive and negative symptoms. Patients moving from stable to exacerbated states had an increase in both positive and negative symptoms, and patients with a poor history of treatment response had both more positive and more negative symptoms than responsive patients in a stable state. These results do not support the view that subgroups of patients have predominantly either negative or positive symptoms.     

Carbon monoxide exposure and information processing during perceptual-motor performance

Summary This study examined the influence of exposure to ambient carbon monoxide resulting in final carboxyhemoglobin (COHb) levels of approximately 5.0% on the ability to process information during motor performance. Subjects (n=16) performed a primary reciprocal tapping task and a secondary digit manipulation task singly and/or concurrently during 2.5 h exposure to room air (0 ppm CO) or 100 ppm CO. Five levels of tapping difficulty and two levels of digit manipulation were employed. Tapping performance was unaffected when COHb levels were as high as 5%. However, at this level of COHb it was noted that CO exposure interacted with task difficulty of both tasks to influence reaction time on the digit manipulation task. It was concluded that motor performance was not influenced by exposure to CO leading to COHb concentrations of 5%. Task difficulty was a significant factor mediating behavioral effects of CO exposure.This work was supported in part by the U.S. Environmental Protection Agency under grant R808177010 and the U.S. National Institutes of Health under grant RR07099. (Although the research described in this article has been funded in part by the EPA through grant RR07099 to the Institute of Environmental Stress, it has not been subjected to the agency's required peer and policy review and therefore does not necessarily reflect the views of the angency and no official endorsement should be inferred.)     

Effect of desmopressin on normal and impaired memory

In view of the reported influence of vasopressin on the memory process of animals, trials were carried out on normal subjects and patients with memory disorders using the vasopressin analogue desmopressin. No beneficial effects could be demonstrated.     

Early surgery for ruptured cerebral aneurysm

Preliminary experience with 150 consecutive cases of ruptured cerebral aneurysms operated on within 48 hours is reported. The rationale of this emergency procedure is to prevent early rerupture and also to prevent neurological ischaemic consequences of the subarachnoid haemorrhage likely to develop in the first week after a rupture. The acceptable outcome of the surgically treated cases (87% excellent and good outcome) has been favourably matched to those of a group of equal number of consecutive cases seen in suitable condition for surgery within 48 hours by medical personnel but that remained unoperated for various reasons. The incidence of delayed neurological ischaemia as the definite cause of death is lower in the group operated on in the acute stage than those with delayed surgery, although the overall incidence of clinical vasospasm does not seem significantly lower than in the delayed surgery group.