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Biomedical subjects

J M Zhao

Publications and source records attributed to J M Zhao.

26 records · Page 2Linked to original sources
PubMed1988

"Mild" cluster headache(?).

Three cases of what could be considered "mild" cluster headache have been described. All three patients were generally able to carry out their work during attacks; all three were men and had unilateral headache with the predominant pain in the ocular region. Relatively few symptoms and signs indicated autonomic system involvement, but at least tearing was invariably present on the symptomatic side. The bouts were generally short-lasting in two of the patients (and partly in the third one), fitting the pattern of "mini-bouts". Thus, in one of the cases four of the five major criteria (male sex, excruciating severity, cluster phenomenon, autonomic involvement, and unilaterality) were present. In the two other patients the full-blown cluster phenomenon was lacking. Such cases may represent the left-side slope of a "Gaussian severity distribution scale" with regard to cluster headache.

Adult↗
PubMed1988

Cluster headache: on the significance of so-called minibouts.

Cluster headache periods (bouts) have, at the lower end of the scale, been supposed to last for periods as short as 1-2 weeks. Patients who usually have bouts of ordinary duration occasionally have brief attacks in the remission phase ("abortive attacks"). The group described here had a temporal pattern, clearly at variance with both these patterns: The six patients had mostly or entirely bouts of less than 1 week's duration. We have termed such short-lasting bouts minibouts, on the supposition that such cases belong within the cluster headache cycle. All the patients were men and had a history of unilateral headache without side shift, and usually the solitary attacks had some autonomic accompaniments, although of a moderate degree. In four cases only mild attacks occurred, whereas in two cases the attacks were rather severe and not consistent with full working ability. The group as such may not be homogeneous. The nosologic status of patients with bouts lasting only 1-2 days is somewhat uncertain. As long as the substrate of cluster headache is not outlined, the lower end of duration of minibouts cannot be accurately identified. The fact that three patients recently have experienced bouts of ordinary length strengthens the view that such cases really belong to the cluster headache cycle.

Adult↗
PubMed1986

Similarity of the conformation of diphtheria toxin at high temperature to that in the membrane-penetrating low-pH state.

At high temperature, nicked free monomers of diphtheria toxin undergo a transition to a thermally denatured state, with a midpoint of 45-50 degrees C. In this report, the high-temperature (60 degrees C) conformation has been compared to the native (neutral pH) and low-pH (pH less than 5) conformations. The low-pH and high-temperature conformations are similar although not identical. As in the conformation at low pH, and unlike the toxin in its native conformation, the protein in its conformation at high temperature is hydrophobic, has low fluorescence intensity, and has increased exposure of tryptophan to aqueous solution. As at low pH, at high temperature the circular dichroism spectrum shows at most only partial unfolding of secondary structure. In contrast, the conformation of the toxin in guanidinium chloride is much closer to a random coil. The effects of high temperature and low pH interact in the sense that sensitivity of the native conformation to one is increased by the other. That is, the transition temperature between native and thermally denatured states is decreased as pH is decreased, and the transition pH between neutral-pH and low-pH states is increased as temperature is increased. This implies that there is some region on the protein where high temperature and low pH can disrupt conformation in a similar manner. Taken together, these results indicate that the low-pH and high-temperature conformations can both be defined as partially denatured states, even though unfolding may not be extensive at low pH. Similar behavior may occur in other proteins that undergo functionally important conformational disruption at low pH.

Chemical Phenomena↗
PubMedDate not supplied

Corneal sensitivity during and outside attacks of cluster headache.

Corneal sensitivity has been studied in cluster headache (n = 38) and controls (n = 16). The patients were studied either during remission (n = 20), interparoxysmally in a bout (n = 17), or during attacks (spontaneously occurring attacks (n = 5) and nitroglycerin-provoked attacks (n = 6). For the measurements, a Cochet-Bonnet esthesiometer was utilized. This esthesiometer has a 6 cm long, adjustable nylon monofilament, which can be reduced in length by 0.5 cm at a time, the length of the filament determining the pressure exerted onto the corneal surface. All controls sensed the pressure at 6.0 cm filament length. In 5 cluster headache patients (remission, n = 4; cluster period, n = 1) a slight reduction in corneal sensitivity was found. No statistical difference was, however, found between any of the groups tested, and there was no asymmetry as far as averages were concerned.

Adult↗
PubMedDate not supplied

SUNCT syndrome: VIII. Pupillary reaction and corneal sensitivity.

SUNCT is a newly described headache characterized by shortlasting, unilateral attacks of a neuralgiform character, accompanied by conjunctival injection and tearing on the symptomatic side. At present, 8 patients have been observed, all males. In the present work, vertical pupillary diameters have been estimated by the binocular, Whittaker infrared pupillometer (Gulf & Western). Measurements have been carried out both during the basal state and after topical, pharmacologic stimulation (by sympathicomimetic agents, i.e. tyramine (2%), OH-amphetamine (1%) and phenylephrine (1%). In the basal state, there was no clear tendency to anisocoria. After sympathicomimetic drugs, there was a tendency to underreaction on the symptomatic side, mainly as regards the indirectly acting ones (OH-amphetamine and tyramine). These two agents should supposedly give similar results, but, nevertheless, the results partly deviated. Phenylephrine did not invariably normalize the symptomatic/non-symptomatic side ratio. Corneal sensitivity was investigated with the Cochet-Bonnet esthesiometer. Two of 6 patients studied outside attack showed moderately lowered values on the symptomatic side. During attack, there seemed to be reduced corneal sensitivity in both patients investigated, in one bilaterally, in the other, on the symptomatic side only.

Administration, Topical↗