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Joseph F Antognini

Publications and source records attributed to Joseph F Antognini.

5 recordsLinked to original sources
PubMed2002

C-fos induction in rat superficial dorsal horn following cutaneous application of noxious chemical or mechanical stimuli.

The method of c-fos immunodetection was used to map the distributions of neurons in the lumbar spinal dorsal horn that were activated following intracutaneous (i.c.) microinjection, or iontophoretic application, of different irritant chemicals to the lateral hindpaw of rats. Microinjections (1 microl) of histamine, serotonin (5-HT), nicotine, capsaicin, or formalin each elicited similar distributions of Fos-like immunoreactivity (FLI) in laminae I-II of the ipsilateral superficial dorsal horn, with little or no FLI in deeper laminae or contralaterally. In laminae I and II, FLI cell counts were significantly higher following i.c. histamine, 5-HT, capsaicin, formalin, and noxious pinch, compared to i.c. saline controls. Capsaicin-evoked FLI was dose-dependent. Multivariate analysis of variance revealed no significant difference in spatial distributions of FLI induced by any of the chemical or pinch stimuli. Iontophoretic application of histamine, 5-HT, or nicotine also elicited similar distributions of FLI in the superficial dorsal horn, and cell counts of FLI were significantly higher compared to controls receiving iontophoretic vehicle (methyl cellulose). These results indicate either that individual laminae I-II neurons are activated by each of the irritant chemicals, or that neurons selectively responsive to a given irritant are comingled without any apparent laminar segregation.

Administration, Cutaneous↗
PubMed2002

Isoflurane, but not halothane, depresses c-fos expression in rat spinal cord at concentrations that suppress reflex movement after supramaximal noxious stimulation.

UNLABELLED: We investigated the effects of isoflurane and halothane on the induction of fos-like immunoreactivity (FLI) in the rat lumbosacral spinal cord after supramaximal noxious mechanical stimulation of the hindpaw. Compared with unstimulated controls (0.9% isoflurane), noxious stimulation at 0.9%-1.5% elicited significant (0.9%-1.5% isoflurane) increases in FLI bilaterally. FLI was distributed mainly in the superficial dorsal horn (laminae I-III) and, to a lesser extent, in the deep dorsal horn (laminae IV-VI) and intermediate zone (lamina VII), with three- to fivefold greater labeling ipsilaterally. At 1.8% isoflurane, mean FLI counts in all laminar regions were significantly smaller (1.7 +/- 1.3 per section) compared with the other concentrations (11.4 +/- 9.5, 7.5 +/- 6.8, and 9.7 +/- 6.6 at 0.9%, 1.2%, and 1.5%, respectively) but were not different from unstimulated controls. At sacral levels, we observed a bilateral distribution of FLI primarily in superficial laminae in unstimulated controls that was not significantly different at any isoflurane concentration. FLI counts were not significantly different across groups receiving halothane (0.9%-1.5%). FLI was reduced only at isoflurane concentrations that depressed both gross, purposeful movement and reflex withdrawal, whereas halothane did not cause depression even at concentrations that depressed withdrawal reflexes. Isoflurane and halothane may have differing effects on neuronal function and responses to noxious stimulation. IMPLICATIONS: Isoflurane depressed neuronal activity in the spinal cord as measured with fos-like immunoreactivity (FLI), but this occurred only when reflex withdrawal responses were abolished. Halothane, however, did not depress FLI, even at concentrations sufficient to block reflex withdrawal. These two anesthetics may have differing effects on neuronal function and responses.

Anesthetics, Inhalation↗
PubMed2002

Does the immobilizing effect of thiopental in brain exceed that of halothane?

BACKGROUND: Recent studies suggest that anesthetics such as isoflurane act in the spinal cord to suppress movement that occurs during noxious stimulation. The authors examined the effect of halothane and thiopental on suppression of noxious-evoked movement using a model of differential anesthetic delivery. They hypothesized that halothane and thiopental, similar to isoflurane, would suppress movement primarily via an action in spinal cord. METHODS: Goats were anesthetized and prepared for differential anesthetic delivery. Anesthesia was maintained with halothane (n = 5) or thiopental (n = 5). Anesthetic requirements were determined (noxious clamp on a dewclaw for 1 min) during halothane or thiopental (via infusion) delivery to the whole body and delivery only to the head. RESULTS: Control (whole body) halothane requirement was 0.9 +/- 0.2%; halothane requirement in the head during differential delivery was 3.4 +/- 1% (P < 0.01). During selective halothane delivery, the electroencephalogram was greatly depressed or was isoelectric even though the animals moved during noxious stimulation. Control (whole body) plasma thiopental requirement was 20 +/- 10 microg/ml. When thiopental was selectively delivered to the head, the electroencephalogram was active in all five animals, and cranial thiopental requirement was 42 +/- 6 microg/ml (P < 0.01). CONCLUSION: These data suggest that halothane and thiopental, like isoflurane, act in spinal cord to suppress movement occurring with noxious stimulation. However, halothane appears to be less potent in the brain as evidenced by the electroencephalogram data, suggesting that action in spinal cord plays a more significant role for halothane than for thiopental.

Anesthetics, Inhalation↗
PubMedDate not supplied

Safety of regional anesthesia in Eisenmenger's syndrome.

BACKGROUND AND OBJECTIVES: Eisenmenger's syndrome is characterized by right-to-left or bidirectional shunting and pulmonary hypertension. Perioperative risk is high for noncardiac surgery, and many clinicians avoid regional anesthesia because of the potential deleterious hemodynamic effects. We determined perioperative mortality based on published reports describing anesthetic management in patients with Eisenmenger's syndrome. METHODS: A literature search identified 57 articles describing 103 anesthetics in patients with Eisenmenger's syndrome. An additional 21 anesthetics were identified in patients receiving regional anesthesia for labor. RESULTS: Overall perioperative mortality was 14%; patients receiving regional anesthesia had a mortality of 5%, whereas those receiving general anesthesia had a mortality of 18%. This trend favored the use of regional anesthesia but was not statistically significant. A better predictor of outcome was the nature of the surgery (and presumably the surgical disease). Patients requiring major surgery had mortality of 24%, whereas those requiring minor surgery had mortality of 5% (P <.05). Patients in labor receiving regional anesthesia had a mortality rate of 24%, and most of these occurred several hours after delivery. CONCLUSIONS: This review of anesthesia and surgery in patients with Eisenmenger's syndrome reveals that most deaths probably occurred as a result of the surgical procedure and disease and not anesthesia. Although perioperative and peripartum mortalities are high, many anesthetic agents and techniques have been used with success.

Adult↗