PubMed HealthSearch

Biomedical subjects

W E Adams

Publications and source records attributed to W E Adams.

At least 19 recordsLinked to original sources

Alloxan analogues as potential pancreatic-imaging radiopharmaceuticals.

Three families of alloxan derivatives, 5-arylthiobarbituric, 5-aryliminobarbituric, and 5-aryldialuric acids, were prepared as prospective radioiodine-transporting radiopharmaceuticals for the delineation of pancreatic insulinomas. Members of each class were screened for effects on blood sugar levels in a rat glucose tolerance assay. Transient hyperglycemia was observed with 5-(2,4-dichlorophenyl)iminobarbituric acid. No agent evaluated induced permanent diabetes at the doses tested.

Alloxan

Studies of DNA damage in rat pancreas and liver by 6-diazo-5-oxo-L-norleucine, ethyl diazoacetate and azaserine.

One hour following intraperitoneal injection of the pancreatic and liver carcinogen azaserine, 10 mg/kg (0.06 mmol/kg), DNA damage is present in both pancreas and liver of Wistar/Lewis rats as determined with alkaline sucrose gradients. Single injections (0.06 mmol/kg) of either of 2 structural analogues of azaserine, 6-diazo-5-oxo-L-norleucine (DON) and ethyl diazoacetate (EDA), do not damage pancreatic or liver DNA. EDA administered at 0.5 mmol/kg damages liver DNA, but not pancreatic DNA. Total radioactivity in pancreas and liver of Wistar rats 1 h after intravenous injection of [14C]azaserine, (10 microCi/kg), is 2.8 and 1.3 times respectively, the level of 14C-activity in pancreas and liver following injection [14C]EDA. Three to four times as much [14C]EDA localizes in the liver of Wistar rats as in the pancreas. Azaserine (0.06 mmol/kg weekly for 6 weeks) induces atypical acinar cell nodules (AACN) in pancreas of Wistar/Lewis rats. DON (0.06 mmol/kg weekly for 6 weeks) induces an elevated incidence, but low number of AACN in pancreas. EDA (0.10 mmol/kg weekly for 6 weeks) does not induce pancreatic AACN.

Animals

Ventriculoperitoneal shunt function: evaluation by sonography.

The function of ventriculoperitoneal shunts was evaluated by ultrasonography in 17 patients. In 10 of 15 patients with properly functioning shunts, a small amount of free intraperitoneal fluid was found. However, absence of demonstrable fluid did not reliably indicate shunt malfunction. No asymptomatic patients had large amounts of ascites or loculated fluid collections, both of which were considered pathologic in shunt patients.

Cerebrospinal Fluid Shunts

Significance of intracranial hypertension in severe head injury.

Measurements of intracranial pressure (ICP) were begun within hours of injury in 160 patients with severe brain trauma, and continued in the intensive care unit. Some degree of increased ICP (greater than 10 mm Hg) was present on admission in most cases (82%), and in all but two of the 62 patients with intracranial mass lesions requiring surgical decompression; ICP was over 20 mm Hg on admission in 44% of cases, and over 40 mm Hg in 10%. In patients with mass lesions only very high ICP (greater than 40 mm Hg) on admission was significantly associated with a poor neurological picture and outcome from injury, while in patients with diffuse brain injury any increase in ICP above 10 mm Hg was associated with a poorer neurological status and a worse outcome. Despite intensive measures aimed at prevention of intracranial hypertension, ICP rose over 20 mm Hg during the monitoring period in 64 of the 160 patients (40%). Postoperative increases in ICP over 20 mm Hg (mean) were seen in 52% of the patients who had had intracranial masses evacuated, and could not be controlled by therapy in half of these cases. Even in patients without mass lesions, ICP rose above 20 mm Hg in a third of the cases, despite artificial ventilation and steroid therapy. Of the 48 patients who died, severe intracranial hypertension was the primary cause of death in nearly half and even moderately increased ICP (greater than 20 mm Hg) was associated with higher morbidity in patients with mass lesions and those with diffuse brain injury. Measurement of ICP should be included in management of patients with severe head injury.

Brain Injuries