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Biomedical subjects

O J Andy

Publications and source records attributed to O J Andy.

At least 73 records · Page 4Linked to original sources

Laparoscopic cholecystectomy. Leave no (spilled) stone unturned.

Stones are sometimes spilled at the time of cholecystectomy. Retrieval may be difficult, especially during laparoscopic cholecystectomy. Little is known about the natural history of missed stones which are left behind in the peritoneal cavity. We present a case in which a patient developed an intraabdominal abscess around such a stone. The abscess recurred after drainage and removal of the stone was needed for resolution. This case suggests that care should be taken to avoid stone spillage, and that stones which are spilled into the abdomen should be retrieved.

Cholecystectomy, Laparoscopic↗

Adjunctive brainstem behaviors in the rat.

UNLABELLED: Adjunctive behaviors refers to behaviors that are "out of context" and/or excessive in amount. The terminology was first used for unexplained behaviors associated with food pellet ratio contingencies in food deprived rats (Falk, 1971). Clinically, unrelated and complex excessive behaviors were also noted with brainstem and diencephalic discharges (Andy, 1986, 1989 and 1995; Andy and Jurko, 1986). The objective of this study was to develop a model of brainstem generated adjunctive behaviors in the rat. METHOD: Sixty-one adult rats were used. Kindling was induced by mechanical and DC electrical perturbations in the midbrain. Nine different treatment groups were established in which lesions and drugs were used separately and in different combinations. Cocaine was used to accentuate, and dextrorphan to attenuate the kindling process. Behaviors were visually analyzed and recorded by video camera; they were not quantified. DC stimulation and EEGs were doen with Grass instruments. Recording and stimulation sights were verified histologically. RESULTS: A total of 45 different behaviors were elicited. DC stimulation kindled subjects had significantly more behaviors than did electrode insertion alone and cocaine alone. However, cocaine combined with DC stimulation increased the number and intensity of the kindled behaviors. Dextrorphan tended to facilitate catatonic and sleep states. Behaviors occurred randomly and were unrelated, even when they occurred in clusters. The behaviors were associated with four abnormal EEG discharge patterns. CONCLUSION: We speculate that brainstem behaviors are innate adjunctive drives that are generated in the brainstem reticular formation. They are monitored by the cortex and partially modified by environmental and cortical inputs.

Animals↗

Dextrorphan effects on cocaine and brainstem perturbation.

UNLABELLED: Dextrorphan is a noncompetitive blocker of N-methyl-D-aspartate (NMDA) receptors. Since NMDA blockers are known to reduce the locomotor stimulatory and toxic effects of cocaine, it was speculated that dextrorphan would attenuate cocaine-induced behavioral excitatory motor activity associated with and without mechanical perturbation of the brainstem. TECHNIQUE: Motor activity was recorded following dextrorphan and/or cocaine challenge in 25 SHR rats. Ten were naive subjects. Mini-osmotic pumps delivering cocaine (2.5 mg/0.49 ul/hr) were placed in 15 subjects, and infusion was halted after the third infusion day. On the fifth day either a dextrorphan (25 mg/kg, subcutaneous) or a dextrorphan and cocaine (40 mg/kg, intraperitoneal) challenge was done. Ten rats had bipolar electrode implants in the bilateral brainstem. Five were treated with DC current lesions in each of 12 days over a 3-week period. The effects of brainstem lesions on escape behavior were also evaluated in those five subjects. RESULTS: In the naive subjects, dextrorphan reduced motor activity (P = .0001), whereas combined cocaine and dextrorphan increased motor activity (P = 0.04). In lesioned subjects, dextrorphan decreased motor activity (P = 0.0001). In electrode implant subjects, combined dextrorphan and cocaine challenge decreased the motor activity (P = 0.04). Hyperactivity in the electrode implant group was greater than in the lesioned subjects. Midbrain electrolytic lesions attenuated escape behavior. A variety of behaviors were produced by brainstem lesions. CONCLUSIONS: Dextrorphan and brainstem lesions reduced motor hyperactivity and escape behavior. In electrode implant subjects dextrorphan counteracted the expected cocaine excitatory motor effects. Dextrorphan did not activate nor facilitate seizures.

Animals↗