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J Antonio Aldrete

Publications and source records attributed to J Antonio Aldrete.

18 recordsLinked to original sources
PubMed2006

Nerve root degeneration and regeneration by intrathecal phenol in rats: a morphologic approach.

Intrathecal injection of phenol (ITP) has been used to control intractable pain and spasticity. Direct caustic nerve damage has been postulated as the mechanism of analgesia. Sensation is commonly recovered, suggesting that a spontaneous regeneration process takes place. There is, however, a lack of mechanistic information on ITP therapy. To define morphologically the neurolysis and regeneration phenomena produced by ITP, anesthetized rats were subjected to laminectomy at L5; 5 microl of 22% phenol in saline solution or vehicle (control) was injected. Light and electron microscopy studies of nerve roots were performed at 2, 14, and 60 days after injection. Rats given ITP showed at the early stage a variable amount of roots with signs of infarction characterized by loss of axon-myelin units and thrombosis of intra-root vessels. At 14 days, abundance of macrophages removing debris, open vessels, and nerve sprouts was identified in damaged roots. At this time, non-myelinating glial fibrillary acidic protein-positive Schwann cells were observed in both damaged and apparently undamaged roots. At 60 days, abundance of 2',3'-cyclic nucleotide 3'-phosphodiesterase-positive Schwann cells myelinating newly formed axons was observed in damaged roots. Control rats did not show signs of neural or vascular pathology. Attempting to prevent thrombosis, another group of rats received heparin before ITP; these anti-coagulated rats developed radicular thrombosis, neurolysis, and hemorrhage. In conclusion, neurolysis produced by ITP is associated with acute ischemia (not prevented by heparin) and is followed by vascular, nerve, and myelin regeneration. Our results help understand the lack of efficacy of and some complications by ITP clinical therapy.

Analgesics↗
PubMed2006

Chronic subarachnoid administration of 1-(4chlorobenzoyl)-5methoxy-2methyl-1H-indole-3 acetic acid (indomethacin): an evaluation of its neurotoxic effects in an animal model.

Neuraxial administration of nonsteroid antiinflammatory drugs has been suggested as an alternative in the management of intractable pain, but there is little evidence that the neurotoxic effects of indomethacin by this route of administration have been evaluated. In this study, we evaluated histological neurotoxicity of indomethacin after its subarachnoid administration in guinea pigs. The hypothesis tested was "Does subarachnoid administration of indomethacin produce damage in the spinal cord of guinea pigs?" Ten male guinea pigs were anesthetized, and a polyamide catheter connected to a subcutaneous osmotic micro-pump was implanted at the L2-3 level. Animals were randomly assigned in 2 groups of 5 animals each. Indomethacin or saline solution was administered by continuous infusion (0.5 microL/h) for 14 days. Neurotoxicity was determined by spinal cord histopathology. There was no evidence of toxicity in the histological examinations of either group. These data suggest that subarachnoid administration of indomethacin infusion, at these doses, did not produce lesions typical of neurotoxicity in the spinal cord. We have concluded that epidural administration of indomethacin may be considered an alternative for application in human pain management, although more studies to determine its safety are required.

Animals↗
PubMed2005

Exacerbation of preexisting neurological deficits by neuraxial anesthesia: report of 7 cases.

We undertook this case series to determine if preexisting neurological disease is exacerbated by either spinal or epidural anesthesia. In the website of the Arachnoiditis Foundation, we posted an offer to advise anesthesiologists in cases of neurological problems after either of these techniques was used. Contacts were made first by way of the Internet, confirmed by telephone, and maintained by fax, e-mail, or by special mail. Patients here described were cared for and observed by one of the authors, in a hospital, in Argentina or in Mexico. A total of 7 adult, ASA physical status I and II patients, including 3 men and 4 women, with subtle symptoms of neurological disease before anesthesia, are described. Two patients had continuous lumbar epidural anesthesia, 3 had spinals; in 2 more, attempted epidural blocks led to accidental dural puncture and were converted to subarachnoid anesthetics. All patients accepted neuraxial anesthesia without informing the anesthesiologists that they had mild neurological symptoms before surgery. Because anesthesiologists did not specifically inquire about subclinical neurological symptoms or prior neurological disease, anesthesiologists are advised to carefully inquire about prior neurological disease whether neuraxial anesthesia techniques are considered.

Adult↗
PubMed2004

Smallpox vaccination in the early 19th century using live carriers: the travels of Francisco Xavier de Balmis.

Realizing that the Spanish colonies were being devastated by epidemics of smallpox resulting in thousands of deaths, Charles IV, King of Spain, sent one of his court's physicians to apply the recently discovered vaccine. Without refrigeration, the vaccine was passed from one child to another (boys taken out of orphanages). Francisco Xavier de Balmis and a team that included three assistants, two surgeons, and three nurses sailed from Spain on November 30. 1803. They vaccinated more than 100,000 people from the Caribbean Islands and South, Central, and North America, reaching up to San Antonio, Texas, and then traveled to the Philippines, Macao, Canton, and Santa Elena Island, landing back in Cadiz on September 7, 1806. During his journey, Balmis instructed local physicians on how to prepare, preserve, and apply the vaccine, while collecting rare biologic specimens. On the 200th anniversary of their sailing, recognition is given to this group for conducting what was the first global vaccination campaign that reached Texas and California.

Carrier State↗
PubMed2003

Epidural injections of indomethacin for postlaminectomy syndrome: a preliminary report.

Since there have been side effects reported with the administration of corticosteroids epidurally, their application has been limited. Because some nonsteroidal antiinflammatory drugs have central and spinal antinociceptive actions, we have compared the effects of indomethacin (INM) given by the epidural route to methylprednisolone (MTP). This was a prospective, comparative study in an ambulatory pain care center. Two hundred six patients with recurrent low back pain (Visual Analog Scale >7) and radiculopathy after they had had 2 or more lumbar laminectomies with the diagnosis of "postlaminectomy syndrome" were randomly assigned to 1 of 3 groups. Group I (64 patients) was given 2 epidural injections of lyophilized INM 1 mg. Group II (60 patients) received 2 injections of 2 mg of INM at the same intervals. Group III (82 patients) was treated by 2 epidural injections of MTP 80 mg. In every case, the medication was diluted in 3 mL of 0.5% bupivacaine. Reductions of pain were assessed by changes in the Visual Analog Scale; physical activities, attitude, and medication intake were graded by the Pain Progress Score recorded before each treatment and 2 wk after the last. After each injection, all patients had pain relief to Visual Analog Scale <3. Increased analgesia (P < 0.05) was noted when a double dose of INM was used (Group II) or when 80 mg of MTP was given. The total average scores of the Pain Progress Score showed significant differences at the second injection in Groups II and III only. Physical activity, emotional attitudes, and medication intake were also improved but the changes were not statistically significant. In conclusion, in this group of patients, INM produced adequate analgesia in Groups I and II, with evidence suggesting that 2 mg of INM may produce a similar degree of pain relief as 80 mg of MTP after the second injection. Other nonsteroidal antiinflammatory drugs may be explored in the future for the same purpose.

Analgesia, Epidural↗
PubMed2001

Body temperature and diaphoresis disturbances in a patient with arachnoiditis.

IMPLICATIONS: Arachnoiditis, produced by different causes, is an inflammation of the sac containing the spinal cord and nerve roots. Patients with this disease have severe low back and leg pain, sweating and low grade fever. This case had aberrant skin temperature and sweating in different parts of the body.

Adult↗
PubMedDate not supplied

[Antihyperalgesic activity of chlorimipramine and sodium phenytoin in an induced model of neuropathic pain in rats].

INTRODUCTION: Neuropathic pain results from injury or impairment of the nervous system manifested by pain syndrome. Experimental models have been used to study its effects and how to suppress these. Tricyclic antidepressants (TCA) and anticonvulsant (AC) have been used for treatment. OBJECTIVE: To evaluate the antihyperanalgesic efficiency of intraperitoneal (IP) chlorimipramine (CIP) vs IP phenytoine (DFH) for induced neuropathic pain in an experimental animal model. METHODS: After making a surgical ligature of the sciatic nerve in the right leg of 18 male rats, the time of withdrawal of both claws immersed in hot (45 degrees C) and cold water (10 degrees C) was measured during a four week period before and after IP CIP, DFH, or placebo administered in a double blind study. RESULTS: Significant statistical differences were observed in the time of withdrawal with CIP as compared with DFH and when both groups were compared with placebo (as tested by the paw immersion in hot water). When the thermal stimulus was cold water, an increase of the time of withdrawal was seen with DFH. CONCLUSIONS: These findings suggest that CIP and FS are both effective in the treatment of neuropathic pain in an animal model, as well as for the treatment of secondary hiperalgesia.

Animals↗
PubMedDate not supplied

[Cervical epidural anesthesia for upper extremity surgery using three different formulations of local anesthetics].

OBJECTIVE: To evaluate the efficiency and safety of the cervical epidural blockade (CEB) in upper extremity surgery, using lidocaine 2%, bupivacaine 5% and a mixture of both local analgesics. MATERIAL AND METHODS: Eighty five patients were submitted to upper limb surgery under CEB. They were assigned into one of three groups: group I received 100 mg of 2% lidocaine; group II received 30 mg of 0.5% bupivacaine, and group III received a mixture of 60 mg of 2% lidocaine and 15 mg of 0.5% bupivacaine. We evaluated their effects on vital signs, blockade quality, adverse effects, and patient comfort. RESULTS: Anesthesiologist and surgeon evaluated the technique as "good" in 80% of the patients. Significant differences were found for motor blockade. Group II developed complete motor block (100%). Observed adverse effects were vomiting in groups II and III and dural puncture was present in 6.7% of the cases in group II. CONCLUSIONS: This study confirms the safety of cervical epidural anesthesia for upper limb surgery using three different formulations of local anesthetics.

Adult↗