Investigation of an artificial intelligence technology--Model trees. Novel applications for an immediate release tablet formulation database.

This study has investigated an artificial intelligence technology - model trees - as a modelling tool applied to an immediate release tablet formulation database. The modelling performance was compared with artificial neural networks that have been well established and widely applied in the pharmaceutical product formulation fields. The predictability of generated models was validated on unseen data and judged by correlation coefficient R(2). Output from the model tree analyses produced multivariate linear equations which predicted tablet tensile strength, disintegration time, and drug dissolution profiles of similar quality to neural network models. However, additional and valuable knowledge hidden in the formulation database was extracted from these equations. It is concluded that, as a transparent technology, model trees are useful tools to formulators.     

Toluene vapor exposure and urinary excretion of hippuric acid among workers in China.

A factory survey was conducted in three provinces in China from 1985 to 1989. The time-weighted average toluene concentrations in breathing zone air were monitored by diffusive sampling, whereas hippuric acid (HA) concentrations in shift-end urine samples were measured by high performance liquid chromatography (HPLC). Exposed workers (456 men and women) were those for whom toluene (up to 548 ppm toluene) accounted for greater than or equal to 90% of total exposure (by vapor concentration in ppm), whereas 517 nonexposed controls were recruited from the same factories or from factories of the same region. There was a linear correlation between the intensity of toluene exposure and HA concentration in the shift-end urine. Comparison of the results with findings in the literature shows that the toluene-induced increase in urinary HA concentration among workers in China is significantly smaller than the published values, whereas HA concentrations in urine samples from nonexposed controls are comparable to the levels previously reported.     

Resuscitation in northern Iraq.

The principles of Advanced Trauma Life Support (ATLS) were adopted by a Royal Navy surgical team deployed to northern Iraq. Over a 6-week period, 18 casualties of both military and civil trauma required active resuscitation, 10 being under the age of 16 years. Triage of multiple casualties was necessary on three occasions. Two patients died. It was difficult to exclude cervical spine injury. Venous cut-down was frequently unsuccessful, so that internal jugular vein cannulation was life-saving. Crystalloid was used as the primary infusion without apparent disadvantage. Cross-matched blood was unavailable and one patient died with haemolysis after massive transfusion. Hypothermia was a problem despite the high environmental temperature. Laboratory and radiological facilities were extremely limited. Non-medical staff were trained most effectively to assess vital signs, although sophisticated monitors became available. These problems are discussed and compared with previous experience. Recommendations are made to improve future outcome.     

Nitric oxide: a revolution of free radicals theory of aging

There are two kinds of free radicals in the aging process, 'bad' and 'good'. Nitric oxide is a good free radical.     

Further studies on interactions between periaqueductal gray, nucleus accumbens and habenula in antinociception.

Previous findings from this laboratory with the intracerebral microinjection technique suggested that the periaqueductal gray (PAG), nucleus accumbens, and habenula might constitute a unidirectional loop to play their roles in pain modulation. In the present study we demonstrate that intra-habenular injection of naloxone antagonizes the analgesia elicited by morphine injected into the periaqueductal gray (PAG) and that intra-accumbens injection of naloxone is capable of attenuating the analgesic effects of morphine injected into the habenula. These results indicate that the relationships between these nuclei may be more complex than the putative unidirectional loop.     

Trephine craniotomy in neurosurgery]

For three years, we have performed craniotomy with a 5 cm diameter trephine through a linear incision. 53 craniotomies were done in 49 patients. This simple and time-saving method produced little bleeding and slight injury to the brain. The technique allowed the surgeon to spend most of his time at the management of lesion. Healing of wound was rapid and brain edema was minimal.     

The efficacy and limitations of percutaneous endoscopic gastrostomy.

We analyzed 64 percutaneous endoscopic gastrostomy procedures performed by us between 1986 and 1990. Thirty patients had neurologic disease; 16 had head and neck cancers; eight had other malignancies; two had acquired immunodeficiency syndrome; and eight had other problems. Seven patients died within 30 days of complications (n = 4) or the primary illness (n = 3). Mean follow-up was 6 months; an additional patient died of aspiration and eight others died of their underlying illness. There were 19 complications (32%). Four wound complications occurred. Nine patients developed aspiration pneumonia within 3 days of the procedure, four of whom died in the hospital. Of the 24 patients with a history of aspiration, nine experienced aspiration during or after percutaneous endoscopic gastrostomy. Patients with a history of aspiration were more likely to have perioperative aspiration pneumonia, and patients who experienced aspiration were more likely to die.     

Mortality and survival of the Down's syndrome population in Western Australia

ABSTRACT. From 1976 to 1984, there were 149 Down's syndrome live births in Western Australia. Where previously the coexistence of congenital heart disease was a major determinant of early mortality, current survival rates do not reflect this. Survival rates have significantly increased over the last decade: particularly so for those with coexistent congenital heart disease. Projected frequencies for Down's syndrome persons in Western Australia are expected to significantly increase. This rise in prevalence will have major economic effects on the planning and delivery of health care for this population.     

The effects of hyperthyroidism on oesophageal motility.

This study, evaluating the effects of hyperthyroidism (HT) in oesophageal motility, depended on an oesophageal radionuclide transit test. A modified standard method was used to calculate: (a) total mean transit time (MTT), (b) residual fraction (RF) and (c) retrograde index (RI) in a supine position. Eighteen untreated patients with HT and 25 normal volunteers (NV) with a similar age distribution were included in this study. The results showed that oesophageal motility in patients with HT was worse than in the normal controls (P < 0.05 by Student's t-test). The correlation of MTT, RF and RI with size and function of thyroid glands in the patients with HT were calculated to explain the effects of HT in oesophageal motility. The results showed that neither the size nor the function of the thyroid glands in HT affected oesophageal motility.