Biomedical subjects
Publications and source records attributed to J D Clark.
As hospitals become more accountable to purchasers and consumers, they will need to be more responsive to legitimate questions about hospital use, costs, and quality. Small area analysis, because of its simplicity and ease of understanding, will be at the center of many of these discussions.
Explore the source record for details and available documents.
The Michigan Health Data Corporation is a major reason why Michigan enjoys voluntary handling of health care data, it is also a potential cornerstone for continuance of a voluntary, but controlled, vehicle for exchanging necessary information.
The typical patient with post-traumatic hypopituitarism is a young adult male presenting months to years after an automobile accident, following which he was unconscious for several days. He will probably have sustained a fracture of the base of the skull and on recovery is likely to have permanent visual or other neurological sequelae. Temporary or permanent diabetes insipidus may have occurred. The features of panhypopituitarism such as weight loss, fatigue, faintness, loss of libido, and impotence may have been ascribed to depression or the "postconcussion syndrome" and often inappropriate treatment and rehabilitation advised. The striking feature on review of the literature is that the pathological consequences of head injury to the pituitary and hypothalamus have been well described, while only 47 cases of traumatic hypopituitarism have been reported. The most likely reason for this disparity is that head injury of sufficient severity to cause hypothalamic and pituitary damage commonly led to death. More patients now survive, owing to the availability of intensive care; accordingly, most cases have been reported in the last 15 years. However, several patients are described in whom the initiating head injury was not associated with a skull fracture or followed by coma. We recommend that patients with major head injury (defined by post-traumatic amnesia greater than 24 hours), and in particular those with fractures of the base of the skull or diabetes insipidus should be closely monitored for symptoms and signs of endocrine dysfunction and appropriate dynamic pituitary-function tests performed.
Groups of fentanyl-droperidol-pentobarbital-anesthetized dogs (n = 6 dogs/group) were given IV saline solution (control group), graded doses of naloxone (0.01, 0.1, 1.0, 10.0 mg/kg) or fixed doses of 4-aminopyridine (0.5 mg/kg), yohimbine (0.4 mg/kg), or doxapram (5.0 mg/kg) alone or in combination with a fixed dose of naloxone (1.0 mg/kg). The purpose was to determine which drug or drug combination would produce arousal most quickly without producing obvious undesirable side effects. Control group mean arousal time, mean walk time and mean duration of postarousal sedation were 66.1 minutes, 112.4 minutes and 5.6 hours, respectively. Naloxone (1.0 mg/kg) decreased mean arousal time to 10.8 minutes without significantly decreasing mean walk time or mean duration of postarousal sedation. The combination of naloxone + doxapram decreased mean arousal time and mean walk time to 1.0 minute and 57.1 minutes, respectively, without decreasing mean duration of postarousal sedation. In all groups, emergence from anesthesia was smooth. Relapses or undesirable side effects were not observed. Naloxone + doxapram is superior to naloxone alone for arousal of fentanyl-droperidol-pentobarbital-anesthetized dogs.
Three patients with acetaminophen overdose were observed to have dark-brown urine at an early stage of their illness. Subsequently, acute anuric renal failure and hepatic dysfunction developed in all three. p-Aminophenol was identified by chromatographic and colorimetric methods in the urine of each case and is thought to be responsible for the discoloration.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A brief summary of the objectives of the Treatment Study Group and its activities to date is given and a Class II Division 2 case treated without extractions is presented.
Explore the source record for details and available documents.
Groups of atropinized dogs (6 dogs/group) were sedated with xylazine (2.2 mg/kg of body weight, IM). At recumbency, the dogs were given IV saline solution (control groups), yohimbine (0.05, 0.1, and 0.2 mg/kg), 4-aminopyridine (4-AP; 0.3, 0.6, and 0.9 mg/kg), doxapram (0.5, 1.0, 2.0, and 4.0 mg/kg), or the smallest dose of these antagonists in dual combinations or in triple combination. Two additional groups were sedated with an overdose of xylazine (11 mg/kg, IM). At recumbency, 1 of these groups was given saline solution IV and the other group was given yohimbine IV (0.4 mg/kg) as the antagonist. With the 2.2 mg/kg dose of xylazine, control mean arousal time (MAT) and mean walk time (MWT) were 15.5 minutes and 24.8 minutes, respectively. These values were decreased by the individual antagonists to 0.5 to 2.5 minutes and 0.9 to 7.4 minutes, respectively. Approximate equipotent doses of antagonists (mg/kg) were: yohimbine, 0.2; 4-AP, 0.6; and doxapram, 0.5. Relapses did not occur after yohimbine or 4-AP. With doxapram, muscle tremors and spasms, abnormal postures, or aggressive behavior occurred in several dogs and several dogs had partial or complete relapses. The small doses of individual antagonists were synergistic with regard to MAT, MWT, and duration of residual sedation, but the various combinations of antagonists were not more effective in these regards than were larger doses of the single antagonists. With the overdose of xylazine, control MAT and MWT were 41.5 minutes and 144.5 minutes, respectively. Yohimbine decreased these values to 2.2 minutes and 2.5 minutes, respectively. Relapses did not occur.(ABSTRACT TRUNCATED AT 250 WORDS)
Groups of atropinized dogs (6 dogs/group) were sedated, using xylazine HCl (2.2 mg/kg of body weight, IM) or acepromazine maleate (0.25 mg/kg, IM), and were anesthetized to loss of pedal reflexes, using thiopental, IV. The dogs were given 1 of the following test antagonists, IV: saline solution (2 ml; control group), 4-aminopyridine (4-AP; 0.5 mg/kg), yohimbine (0.4 mg/kg), doxapram (5.0 mg/kg), or dual combinations of the latter 3 substances in the same doses as used for each agent. In xylazine-treated dogs, the mean dosage of thiopental required to induce anesthesia was 4.8 mg/kg. Control mean arousal time (MAT) and walk time (MWT) were 37.1 minutes and 53.8 minutes, respectively. These values were decreased to less than 2 minutes and less than 3 minutes, respectively, by yohimbine, 4-AP + yohimbine, and doxapram + yohimbine. With doxapram and with 4-AP + doxapram, MAT was less than 2 minutes and MWT was less than 8 minutes. In acepromazine-treated dogs, the mean dosage of thiopental required for anesthesia was 15.0 mg/kg. Control MAT and MWT were 20.7 minutes and 36.5 minutes, respectively. These values were decreased to 8.1 minutes and 18.1 minutes, respectively, by doxapram, and to 3.5 minutes and 19.9 minutes, respectively, by doxapram + yohimbine. Doxapram, 4-AP + doxapram, and doxapram + yohimbine caused periodic extensor rigidity before and during arousal. This rigidity was accompanied by opisthotonos in 2 dogs of the doxapram + yohimbine group and may have been mild tonic seizures.(ABSTRACT TRUNCATED AT 250 WORDS)
The management of toxic shock syndrome poses a challenge to clinicians because the syndrome has only been recently recognized and new complications are still being described. This report describes the major complications which arose in our case and highlights a severe bleeding disorder which was the cause of the patient's death. The bleeding disorder was characterized by normal in vitro coagulation screens, normal platelet aggregation tests, but prolonged skin bleeding time. It was not improved by haemodialysis, platelet transfusion or steroid therapy. We conclude that in cases with severe toxaemia, despite early recognition and appropriate treatment, there is still no effective method of preventing complications. Current avenues for investigation include plasmapheresis, the administration of fresh frozen plasma, and the development of a specific anti-toxin.
A technique for rapidly separating platelets from small quantities of whole blood is described. The isolation method allowed for counting and sizing platelets by electronic means, and counts with this new method were closely correlated with those obtained by phase microscopy. Platelet sizing was possible because of the inert and isotonic nature of the density-gradient medium used in the procedure. The technique was applicable to samples of blood from persons, horses, cattle, sheep, goats, pigs, dogs, mice, rats, guinea pigs, and rabbits. The isolation of platelets from whole blood of various species of animals was necessary for electronic counting because of the great variation in sizes of platelets and erythrocytes and the variable sedimentation properties of animal blood.
Explore the source record for details and available documents.
Young male baboons born in captivity were immunized with an attenuated, cryopreserved schistosomular vaccine derived from gamma-irradiated (50 krad) cercariae of the Puerto Rican strain of Schistosoma mansoni. Protection against a heterologous Kenyan strain of S. mansoni, after percutaneous infection, was assessed. Partial protection (33-53% reduction in worm burden) was obtained in three of six vaccinated-challenged baboons, an unremarkable result. Of greater interest was the fact that all six unvaccinated-challenged control baboons, but only one of the six vaccinated-challenged baboons, had macroscopic egg granulomas on their liver surfaces. This difference in granuloma size was substantiated by measuring hepatic and colonic granulomas. The mean (+/- SEM) hepatic and colonic granuloma diameters for the six unvaccinated baboons were 406 +/- 38 micron and 313 +/- 27 micron, respectively, and for the five "typical" vaccinated-challenged baboons the mean diameters were 283 +/- 27 micron and 202 +/- 23 micron, respectively. Both hepatic and colonic granulomas were significantly smaller in the five typical vaccinated-challenged baboons. Not only did the exceptional vaccinated-challenged baboon have very large hepatic and colonic granulomas, but also it was the only one of its group whose mesenteric lymph node cells were not suppressed in their in vitro proliferative response to a schistosome antigen. These results strongly suggest that granuloma size reduction in the majority of the vaccinated baboons was the result of immunoregulation--i.e., the small postvaccination granulomas were "modulated." Despite their small size, hepatic granulomas in the typical vaccinated baboons were apparently as effective in sequestering egg toxins and preventing hepatocyte damage as the larger granulomas of the control baboons. Smaller, less obstructive granulomas are thought to be more beneficial to the host than large, vigorous granulomas, with respect to lessening chronic disease. The present results give encouragement that a vaccine to ameliorate disease in human schistosomiasis is possible. This effect should add to the attractiveness of partial protection against challenge infections conferred by attenuated larval vaccines, as reported by others, to yield a dually beneficial vaccine for human use.
The study models of a sample of 51 cases with Class II division 1 malocclusions treated in the General Dental Service in Scotland, were investigated and analysed with respect to the changes which had taken place in the overjet, overbite and incisor alignment. Residual spacing in the arches was also measured. Occlusal Index scores were calculated at the start and finish of treatment. The results suggest that only a limited measure of success was achieved; they indicate a need to improve orthodontic treatment standards.
Explore the source record for details and available documents.