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Biomedical subjects

J N Ghia

Publications and source records attributed to J N Ghia.

At least 19 recordsLinked to original sources
PubMed1988

Alterations in cerebrospinal fluid uridine, hypoxanthine, and xanthine in head-injured patients.

1. Examination of the cerebrospinal fluid (CSF) of head-injured patients reveals that the concentration of intraventricular xanthine is elevated and that of uridine is decreased relative to those of adult lumbar CSF. 2. No correlations were observed between CSF lactate and CSF hypoxanthine, xanthine, or uridine, suggesting that changes in purine metabolites and the pyrimidine nucleoside do not index similar cellular events as does lactic acid production. 3. Ventricular CSF from hydrocephalic infants had uridine and hypoxanthine concentrations not significantly different from those of normal adult lumbar CSF, but xanthine was significantly elevated. 4. Since uridine has anticonvulsant properties and is a crucial substrate for cerebral metabolism, it may be useful to evaluate this pyrimidine for use in the management of patients with head injury.

Adult↗
PubMed1985

A retrospective study of the incidence and causes of failed spinal anesthetics in a university hospital.

One hundred sequential spinal anesthetic procedures were reviewed retrospectively to study specifically the incidence and causes of spinal anesthesia. Variables examined included the patient population, the technical aspects of performing subarachnoid tap and subsequent blockade, and the level of training of the anesthetists. We found a 17% incidence of spinal failure, defined as the need to use general anesthesia during the surgical procedure. Failure was found to be significantly associated with a lack of free flow of cerebral spinal fluid, the use of tetracaine without epinephrine, and an increased administration of intravenous supplementation. Forty-one% of the failures represented errors in judgement, either in not properly anticipating the duration of surgery or injecting local anesthetic solution in the absence of a free flow of cerebral spinal fluid. An incidental finding was the lack of documentation in many of the variables examined. We attribute the high incidence of failed spinal anesthesia mainly to technical reasons, most of them avoidable. The use of local and regional anesthesia requires considerable technical skills and demands a precise and total understanding of regional anatomic relationships. With the decreasing use of regional anesthesia in our operating rooms, only those regional anesthesia techniques that require minimum dexterity, such as spinal and epidural anesthesia, continue to be utilized widely; and even these techniques, safe as they are, are being poorly taught.

Adult↗
PubMed1981

Serotonergic activity in man as a function of pain, pain mechanisms, and depression.

Lumbar cerebrospinal fluid levels of 5-hydroxyindoleacetic acid, which are used as indicators of central nervous system serotonergic neuronal activity, were significantly higher in 67 patients with chronic pain and in 32 patients with acute pain (23.6 +/- 3.3 and 23.1 +/- 3.8, respectively) than in 30 patients (8.8 +/- 1.7) who had no pain. However, there was no correlation between levels of 5-hydroxyindoleacetic acid in patients with chronic or acute pain, nor between groups of patients with chronic pain whose pain mechanisms were of psychogenic, sympathetic, somatic, or central origin, based on their responses to differential spinal block; there was also no correlation between levels of depression, as evaluated by the Zung scale, in patients with different types of chronic pain, even though all of these patients were depressed. The elevated levels of 5-hydroxyindoleacetic acid in the depressed patients with chronic pain are not consistent with previous studies on the etiology and types of chronic pain. As recent research indicates that the perception of pain may be modulated by endogenous analgesic systems involving enkephalin and serotonin (5-HT), this study was undertaken to clarify the association between 5-HT activity and nociception. Our findings did show a link between acute noxious stimulation and central increases in serotonergic activity. However, we could not differentiate between pain mechanisms and degree of depression. Our studies did indicate that, because of both the persistence of pain complaints and the increased levels of brain 5-HT activity, the endogenous analgesic systems are not totally effective as natural inhibitors of pain. Furthermore, the increased depression and continued pain in the presence of elevated 5-HT activity in patients with chronic pain may represent a tolerance or decreased responsiveness to 5-HT.

Adult↗
PubMed1981

Comparative aspects of chronic pain in the head and neck versus trunk and appendages: experiences of the Multidisciplinary University of North Carolina Pain Clinic.

The interdisciplinary University of North Carolina Pain Clinic, in existence since 1973, is a coordination center for research, pre and postdoctoral and resident training, and clinical services. It functions primarily as a tertiary care center for outpatients as a component of the North Carolina Memorial Hospital. Inpatient consultations and therapy direction are carried out on request. Approximately 400 new patient visits and 1,200 consults and return visits are made yearly. The clinic is administered by codirectors from the Departments of Oral and Maxillofacial Surgery and Anesthesiology. Consultants to the clinic include the disciplines of psychiatry, neurosurgery, family medicine, pathology-oral pathology, dentistry, physical therapy, social work and nursing. Support staff includes a head nurse, half-time transcription and half-time general secretary and a financial technician. Facilities consist of an 8-room clinic dual equipped for patient care and clinical research. An adjacent conference room is used for research and patient presentation conferences. In addition to routine examining and interview rooms, a minor procedure operating room is equipped with resuscitation equipment, suction, oxygen, anesthesia machine, a physiologic monitoring system with polygraph, a cryosurgical unit and a radiofrequency lesion generator. A second room is equipped for neurosensory studies of peripheral nerve functions including a battery of tactile-mechanical and thermal threshold stimuli tests, as well as nerve conduction and EMG. A system for psychophysical testing is available through tie-in with a computer, which is located in an adjacent laboratory used for data analysis and also subhuman primate experiments. Another room is equipped with psychophysiologic training equipment, particularly EMG biofeedback. A computer terminal on line to the University IBM 360 is located in the Pain Clinic for use in entering patient-research data. A library with dictating space is available for use by consultants, postdoctoral trainees, and residents.

Chronic Disease↗
PubMed1979

Towards an understanding of chronic pain mechanisms: the use of psychologic tests and a refined differential spinal block.

Forty patients with chronic pain below the waist level were evaluated in a multidisciplinary pain clinic using a refined differential spinal block (DSB) technique. The refinements consisted of verbal instructions to prevent biasing the patients, coupled with a thorough evaluation of verbal and physiologic responses to the block. When demographic and psychologic data were assessed according to pain mechanisms, a pattern of patient groups emerged along a chronic pain continuum. Stress, anxiety, depression, and hysteria, as well as the neurophysiologic and demographic factors, modified the responses to the block. Long-term follow-up of these patients, including repeat DSB procedures and confirmatory anatomic blocks of sympathetic and somatic nerves, validated these impressions. The findings indicate a link between pain mechanisms and psychosocial factors that may directly influence responses to DSB.

Adult↗