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Biomedical subjects

J C Yap

Publications and source records attributed to J C Yap.

26 records · Page 2Linked to original sources
PubMed1990

The effect of fresh orange juice on bronchial hyperreactivity in asthmatic subjects.

We studied 16 mild stable asthmatic subjects to determine if orange juice increases nonspecific bronchial hyperreactivity (NSBH). In 9 subjects, bronchial responsiveness to histamine was assessed before and after water ingestion on the control day, and orange ingestion on a consecutive day. The mean (+/- SD) ratio of log10 PD20 FEV1 after water: log10 PD20 FEV1 before water (1.00 +/- 0.13) was not significantly different from the mean (+/- SD) ratio of log10 PD20 FEV1 after orange: log10 PD20 FEV1 before orange (0.97 +/- 0.12). To avoid the possibility of histamine tachyphylaxis, 7 subjects participated in a second protocol in which histamine PD20 FEV1 was determined on a control day (geometric mean 0.11 mg.) and again two days later, thirty minutes after ingestion of orange juice (geometric mean 0.06 mg). There was no significant difference in the PD20 FEV1 (p = 0.344). Our data show that ingestion of fresh orange juice per se did not heighten NSBH in our subjects. (PD20 FEV1 is the dose of histamine required to produce a twenty percent fall in forced expiratory volume in one second [FEV1]).

Adolescent↗
PubMed1990

The breathing patterns in Chinese and Indian adult males in the supine posture.

The breathing patterns in the supine posture during inspiration from functional residual capacity (simulating the "liver palpation" manoeuvre) were studied in two groups of young adult male Chinese and Indians with each group comprising 30 subjects. Both groups were matched for age, height and weight. Although the findings did not reach a statistically significant level, Indian subjects were found to breathe more with their abdomen compared to the Chinese during the manoeuvre. The two groups behaved similarly when they breathed with increasing amplitude from their resting tidal volume to full inspiratory capacity. There was also no difference between the two groups when they performed the total lung capacity manoeuvre.

Adult↗
PubMed1983

Clinical evaluation of a depth electroencephalography electrode.

Stereo depth electroencephalography (EEG) is of proven benefit in lateralizing and localizing seizure origin in select cases of epilepsy. There are potential hazards and technical considerations inherent with depth EEG, however, that have limited the general applicability of this technique. A new depth EEG electrode with materials and design features that facilitate safe insertion and artifact-free recording has been developed. The design features and technique for inserting the electrode are described. The electrode was evaluated during 2600 hours of implantation and recording in seven patients. With the use of stereotactic techniques, the electrode could be positioned accurately within precise anatomical landmarks such as the amygdaloid nucleus and the hippocampus. After insertion, no hemorrhage or edema was detected along the electrode tracts by third generation computed tomographic scanning. There was no evidence of pyrogenicity or infection. Electrode migration was not observed. A large electrical field could be sampled because of the relatively large surface of the cylindrical depth electrode contacts.

Electrodes, Implanted↗
PubMed1981

A survey of infections in stereotactic surgery.

In 365 consecutive intracranial stereotactic procedures over a 6-year period, there were three postoperative infections; 1 case of increased neurological deficit and 1 of fatality. Staphylococcus aureus was the most common organism involved; however, multiple organisms were seen in 2 cases. Multiplicity of organisms necessitated the use of a broad spectrum of antibiotics in the preoperative and postoperative periods. The method described has permitted an infection rate which compares favorably to other reports in the literature. Perioperative antibiotics, antibiotic-containing irrigation solutions, and careful attention to sterile techniques seem to be instrumental in maintaining a low infection rate in our study. Since the new spheroid design has been used, there have been no infections.

Adolescent↗
PubMed1980

Stereotactic fields of Forel interruption for intractable epilepsy.

Bilateral stereotactic fields of Forel surgery was carried out in 6 adults with chronic intractable epilepsy associated with multifocal EEG abnormalities. During an average 40 months follow-up, a significant reduction in the frequency of generalized tonic-clonic seizures was noted in 4 patients. Complex partial seizures in 3 patients and akinetic-myoclonic seizures in 1 did not respond to surgery. Neuropsychological testing revealed a mild to moderate postoperative cognitive decline in 4 patients. Fields of Forel surgery, while partially effective in generalized tonic clonic seizures, appears justified only in patients with such severe preexisting cognitive deficits, that the benefits of seizure control definitely outweight the risk of further cognitive decline.

Adult↗
PubMed1980

Stereotactic hypophysectomy for intractable pain secondary to metastatic prostate carcinoma.

Stereotactic radiofrequency transfrontal hypophysectomy was carried out in 7 patients with osseous metastasis from prostatic carcinoma resulting in intractable pain. 86% experienced significant pain relief with 5 of 7 demonstrating marked decrease in medication requirement and improved level of function. The procedure was done under local anesthesia only with no mortality and minimal morbidity. Total destruction of the pituitary gland and the development of diabetes insipidus were shown not to be necessary conditions for pain relief.

Aged↗
PubMed1978

Stereotaxic treatment of seizure disorder.

Individuals with intractable epilepsy have a murky existence, fraught with medical helplessness, social rejection and personal despair. Drugs control many, but unfortunately not all, cases of epilepsy. An attempt to elucidate on the indications, selections and rationale for the stereotaxic interruption is made. Three cases of intractable epilepsy treated by stereotaxic Fields of Forel Interruptions are reported with special emphasis on pre and postoperative evaluations. Based on the data so far available, it appears that a significant number of patients with medically intractable epilepsy who are not candidates for "standard" neurosurgical interventions, can be helped further by stereotaxic interruptions with minimal morbidity.

Adolescent↗