Significance of positive spike burst in Reye syndrome

We have previously reported a high incidence of 14-and 6-cps positive spike bursts in comatose patients with Reye syndrome. To further demonstrate this association, positive spike bursts were obtained in three additional cases but only in certain stages during the acute phase of illness. They varied in frequency from 7 to 13 cps, presumably reflecting the degree of slowing of the background EEG activity. A loud noise or other stimuli often precipitated the bursts, particularly when high amplitude delta waves were prominant. We believe that the presence of the positive spike bursts in comatose patients may be of diagnostic significance in Reye syndrome and that an undetermined metabolic or biochemical disturbance may be responsible for their appearance.

Electrically elicited blink reflex in normal neonates

The electrically elicited blink reflex was tested in 30 full-term neonates. Of the two distinctly separate responses, early component R1 and late component R2, R1 was recorded in all but three infants. Its latency, 12.1+/-1.0 msec (mean+/-SD), was significantly greater than that in adults (10.6+/-0.8 msec) despite a considerably shorter length of the reflex arc in infants. Unlike the response in adults, R2 was elicited in only 20 of 30 infants, mostly on the side ipsilateral to the stimulus. The reduction of reflex excitability of R2 in neonates must occur primarily at the level of interneurons since oligosynaptic R1 was elicited with ease whereas polysynaptic R2 was not.

Electrical activity in voluntarily contracting muscle

The collision technique was used to determine the relationship between the electrical potential and the force produced by a voluntarily contracting first dorsal interosseus muscle. The method allows, in effect, synchronization of nerve impulses of asynchronously firing motoneurons subserving voluntary contraction. A compound muscle action potential, M (voluntary), thus recorded as an electrical corollary of muscle contraction, related linearly to the force of contraction under isometric conditions. Using M(voluntary), an approximate percentage of motoneuron pool discharging during a 10-msec period was calculated at various levels of voluntary effort. In ten healthy subjects, it increased linearly with muscle force from 2.4% +/- 1.4% at 0.5 kg to 23.5% +/- 9.6% at 4.5 kg.

Electrophysiological study of anomalous innervation of intrinsic hand muscles

The collision technique was used to study the incidence of anastomosis between median and ulnar nerves in the forearm (Martin-Gruber anastomosis). A motor anastomosis from median to ulnar nerve was found in 57 (17%) of 328 unselected subjects. The anomaly was bilateral in 39 subjects (68%) and unilateral in 18, nine on the right and nine on the left. Both hypothenar and thenar muscles were tested in 77 of 96 hands with the anastomosis (right and left sides combined). Both muscle groups were innervated by the communicating fibers in 63 hands (82%). Anomalous innervation was limited to hypothenar muscles in 13 and to thenar muscles in one hand. In contrast to the high incidence of the anastomosis from median to ulnar nerve, crossover from ulnar to median nerve in the forearm was found in none of 303 subjects tested.

Kinetic analysis of hormone-induced mitoses in epithelial cells of mouse uterus and vagina

The intracellular localization of 3H-estradiol-17beta and 3H-progesterone to the different types of cells in the mouse uterus was investigated using autoradiographic techniques. The kinetics of cell proliferation in the surface epithelium of the uterus and in the vaginal epithelium (basal layer) are analysed by means of cumulative labeling method and mitosis chase method using 3H-thymidine autoradiographic procedures. The results are as follows, (1) Epithelial cell population of the uterine lumen and basal cell population of the vaginal epithelium in the ovariectomized mouse are divided into a major subpopulation of GO cells and a minor subpopulation of proliferating cells. (2) Proliferative potencies of uterine surface epithelial cells and vaginal basal cells in the ovariectomized mouse are regulated by a steroid-independent mechanisms through which the proportion of the GO cell-compartment and Tc value of the proliferating cell-compartment are determined according to their age; as the castrated mouse grows older, Tc value becomes longer and the proportion of the Go cell-compartment becomes larger. (3) If the dose levels of estrogen administered exceed the threshold value, estrogen-dependent cell proliferation will be provoked by transferring the cells in the GO cell-compartment to the proliferating cell-compartment in all or none fashion, and by reducing the Tc value of proliferating cell to 1/2-1/3 of that in the castrated mouse. (4) It is suggested that proliferating cells in the uterine surface epithelium and in the vaginal epithelium turn the cell cycle at a constant Tc value during estrous cycle, and that the tissue growth during estrous cycle is dependent on the size of the proliferating cell-compartment but not on the Tc value. (5) The results obtained from autoradiography of tritiated steroids in the mouse uterus gave a supporting clue to the kinetic data.

Effects of clomiphene citrate and progesterone on resting and proliferative cell-populations in resting and proliferative cell-populations in mouse uterine epithelium

Resting cells (GO cells) of the uterine surface epithelium in castrated mice began to synthesize DNA with high synchrony from 10 hr after the injection of 50 ng of estradiol-17beta with or without 5.5 mug of clomiphene citrate. Highly synchronized DNA synthesis in GO cells elicited with estradiol was delayed approximately 5 hr when the simultaneous administration of 0.5 mg of progesterone was given. In GO cells of castrated mice which received 5.5 mug of clomiphene or 55 mug of clomiphene plus 50 ng of estradiol, DNA synthesis with partial synchrony began 15 hr after the injection. The effects of estradiol were completely suppressed by the administration of 55 mug of clomiphene. It is suggested that the inhibitory action of clomiphene may be due to the competitive blocking of estrogen binding, while progesterone suppresses the estrogen-induced DNA synthesis of the surface epithelium and transfers them to the GO cell-compartment.

A method for estimating the refractory period of motor fibers in the human peripheral nerve

A simple method has been devised to measure the refractory period of motor fibers in man. With paired shocks of just maximal intensity, the second response of the pair was first elicited at an interstimulus interval of 1.00+/-0.20 msec (mean +/- SD in 24 ulnar nerves). With longer intervals there was progressive return of excitability until it recovered completely at 2.88+/-0.72 msec. When paired shocks of 50% supramaximal intensity were used, return of the second response was faster, beginning at 0.77+/-0.18 msec and achieving full recovery at 2.03+/-0.57 msec. The inpulse was conducted at a slower speed than normal, if transmitted at all, during the relative refractory period.

Collision technique. Physiologic block of nerve impulses in studies of motor nerve conduction velocity

Commonly encountered yet not widely appreciated sources of error in the study of motor nerve conduction velocities of the median and ulnar nerves include (1) spread of stimulating current to the nerve not under study, (2) recording a volume conducted potential from distant muscles, and (3) presence of anomalous crossover in the forearm between the median and ulnar nerves. Under these circumstances, it is desirable to block impulses in one nerve without affecting those in the other. This can be achieved simply by collision if a second stimulus is delivered distally to the nerve not being tested.

Electrophysiological study of Bell palsy: electrically elicited blink reflex in assessment of prognosis

The electrically elicited blink reflex was tested serially in 81 patients with Bell palsy. In 56 patients, the reflex returned before excitability of the distal segment of the facial nerve was lost, indicating recovery of conduction across the involved segment before distal degeneration. These patients generally showed a good clinical recovery within a few months after onset. The reflex latency, however, was considerably prolonged during the first month, suggesting demyelination or other pathologic change. The reflex latency was reduced considerably during the second month and returned to normal levels during the third or fourth months. In the remaining 25 patients, direct response to facial nerve stimulation became unelicitable before reflex responses returned, indicating distal degeneration of the nerve. In this group of patients, clinical recovery was prolonged and generally incomplete.

Recovery curves of the blink reflex during wakefulness and sleep

The paired shock technique was used to study the effect of sleep on the excitability of the short latency R1 and long latency R2 components of the electrically elicited blink reflex. During wakefulness, R1 returned, after transient potentiation, to its original level in about 150 ms following the conditioning stimulus. Contrastingly, R2 remained profoundly suppressed up to 800 ms, suggesting sustained reduction of excitability of the polysynpatic reflex pathways after the passage of a preceeding impulse. During non-REM and REM sleep, the recovery curve of R1 was similar in character, although different in time course to the one obtained during wakefulness. However, R2 was potentiated rather than suppressed by the conditioning stimulus during both phases of sleep. These findings indicate that, during sleep, the polysynpatic reflex pathways are not inhibited by a preceeding impulse to the same degree as in wakefulness.

F-wave conduction velocity in the central segment of the peroneal and tibial nerves

A simple method was devised to measure the F-wave conduction velocity (FWCV) in the central segment (knee to spinal cord) of the peroneal and tibial nerves in contrast to the conventional motor nerve conduction velocity (MNCV) in the distal segment (knee to ankle). In 33 normal subjects, the FWCV in the central segment (56.3 +/- 4.9 meters/sec for peroneal nerve; 54.4 +/- 3.6 meters/sec for tibial nerve) was slightly faster than the MNCV in the distal segment (49.5 +/- 3.8 meters/sec; 46.8 +/- 3.4 meters/sec) as measured in the conventional manner. In 4 of 14 patients with the Guillain-Barrĕ syndrome, the F-wave was absent or slowed in the face of normal MNCV indicating more marked slowing of nerve conduction proximally. The average FWCV (36.8 +/- 13.6 meters/sec; 42.2 +/- 9.3 meters/sec) and MNCV (41.4 +/- 8.0 meters/sec; 39.0 +/- 5.6 meters/sec) were considerably decreased compared to the normal values. The F-wave could not be elicited in the lower extremities in 16 of 19 patients with Charcot-Marie-Tooth disease. The FWCV was normal in 10 patients with multiple sclerosis including 3 with clinical findings suggesting demyelination in the conus medullaris.

Electrophysiologic analysis of aberrant regeneration after facial nerve paralysis

The blink reflex, ordinarily elicited only in the orbicularis oculi and not in other facial muscles, can be used to detect synkinetic movements objectively. In 26 of 29 patients tested at least 4 months after facial nerve degeneration, an aberrant blink reflex was recorded in the orbicularis oris on the affected side. Of the remaining three, one had injury to only a peripheral branch of the facial nerve and experienced a return of function with no evidence of synkinesis; in the other two, the affected side of the face was totally paralyzed in the absence of facial nerve regeneration. Synkinetic movements ultimately will occur in nearly all cases following facial nerve degeneration provided that the facial nerve regenerates from a proximal site.

Electrically elicited blink reflex in diagnosis of multiple sclerosis. Review of 260 patients over a seven-year period

The blink reflex obtained from 260 patients with suspected multiple sclerosis was analysed according to clinical criteria for diagnosis. The R1 component was dealyed on one or both sides in 96 of 145 patients with definite diagnosis (66 per cent), 32 of 57 with probable diagnosis (56 per cent), and 17 of 58 with possible diagnosis (29 per cent). The incidence of abnormal R1 rose with increasing duration of illness in each category. When the reflex was analysed according to the clinical localization of the lesion in the 260 patients, R1 was abnormal in 49 of 63 patients with pontine signs (78 per cent), 59 of 104 with other brain-stem signs (57 per cent), and 37 of 93 with no clinical brain-stem signs (40 per cent). Alteration of R2 was less specific but, when seen in the face of a normal R1, was usually associated with clinical signs suggesting lateral medullary lesions. These fingings offer direct evidence that conduction through demyelinated zones in the central nervous system is indeed slowed and that the degree of slowing can be measured objectively by means of this simple technique in man. The high inicdence of delayed R1 in patients with no clinical pontine signs suggests that the test may be used to document a clinically silent pontine lesion in multiple sclerosis and help to establish the anatomical dissemination of pathology.

F-wave conduction velocity in Guillain-Barré syndrome. Assessment of nerve segment between axilla and spinal cord

The F-wave conduction velocity (FWCV) in the central segment (axilla to spinal cord) of the median and ulnar nerves was compared to the motor nerve conduction velocity (MNCV) in the more distal segments in nine patients with mild cases of the Guillain-Barré syndrome. In four patients, FWCV was slow despite normal or borderline MNCV. In four others, both FWCV and MNCV were abnormal. One patient showed slow MNCV with normal FWCV. The average FWCV was significantly decreased (40.9 +/- 12.0 meters/sec for median and 42.9 +/- 8.3 meters/sec for ulnar nerves) when compared to the corresponding normal values (64.3 +/- 6.4 meters/sec and 63.1 +/- 5.9 meters/sec). These data support the hypothesis that the central segment of a nerve is predominantly involved in some patients with Guillain-Barré syndrome.

Cerebral circulation time with ruptured intracranial aneurysms

✓ The cerebral blood circulation time (CT), including the length of the arterial phase, was obtained from rapid serial angiograms in 114 patients with ruptured intracranial aneurysms. The average CT of 7.2 sec, with a mean arterial phase of 3.1 sec, was much longer than the normal average CT of 5.4 sec with its 2.4 sec arterial phase. Longer circulation times were observed with the higher Botterell grades of clinical condition, high arterial perfusion and CSF pressures, and in cases with angiographic evidence of arterial spasm, hematoma, or hydrocephalus. Values of CT greater than 8.0 sec were associated with increased mortality and morbidity and vice versa. The value of the cerebral blood circulation time as a guide to preoperative treatment and to the prognosis of cases of ruptured intracranial aneurysm is suggested.

Hapten-sandwich labeling. I. A general procedure for simultaneous labeling of multiple cell surface antigens for fluorescence and electron microscopy

A hapten-sandwich procedure has been developed for specific labeling of cell surface antigens for fluorescence or electron microscopy. Haptens are azo-coupled to immunoglobulins specific for a cell surface antigen; the hapten-modified cell-bound antibodies can then be visualized by adding fluorescent antihapten antibody, or by adding antihapten antibody followed by hapten-modified markers for electron microscopy. Virus or high molecular weight protein markers are lightly cross-linked before conjugation with hapten to prevent their disruption. Such stable hapten-modified markers, and the accessibility of many different purified anti-azophenyl-hapten antibodies, make it feasible to distinguish more than one membrane antigen in a given labeling experiment. When mouse lymphoid cell populations are labeled with separate markers for Ig and for thymus-associated antigens, many cells exhibit the Ig marker exclusively or the thymic marker predominantly, and some cells are completely free of label.

Alteration of orbicularis oculi reflex by posterior fossa tumors

✓ The orbicularis oculi reflex response to electrical stimulation of the supraorbital nerve was studied in 14 cases of intrinsic brain stem lesions (2 mesencephalic, 6 pontine, and 4 medullary neoplasms, and 2 pontine syrinxes) and 20 cases of lesions extrinsic to the brain stem (6 cerebellar and 14 cerebellopontine angle tumors). The early reflex was abnormal in all but three cases of medullary tumors and one case of cerebellar tumor. Alteration of the early reflex by posterior fossa tumors reflects either delayed conduction through the pons due to intrinsic pontine lesions or extrinsic compression of the pons, or indicates trigeminal or facial nerve involvement by tumor. The late reflex with its direct and consensual components is useful in distinguishing afferent from efferent delay (or block). Mixed patterns suggest combined involvement of the trigeminal and facial nerves or a relatively widespread brain-stem lesion. This simple technique appears to be a useful addition to clinical observation in assessment of posterior fossa tumors.

Orbicularis oculi reflex in coma: clinical, electrophysiological, and pathological correlations

The orbicularis oculi reflex was studied in 48 comatose patients and the results were correlated with clinical and pathological findings. The late component of the reflex was absent or of minimal amplitude in all cases regardless of the site of lesions, reflecting a diffuse suppression of the reticular system rather than a specific or local block in the brain-stem. Alteration of the early component of the reflex, on the other hand, generally indicated primary or secondary structural changes in the pons, although reversible functional or pharmacological block of pontine conduction was also documented.

Deuterium oxide: inhibition of calcium release in muscle

Calcium release, measured as luminescence of the protein aequorin, was measured simultaneously with membrane potential and isometric tension in single muscle fibers of the barnacle (Balanus nubilus). Deuterium oxide inhibited calcium release and isometric tension but did not affect membrane potential, a result consistent with the postulate that deuterium oxide inhibits the coupling between excitation and contraction.

Orbicularis oculi reflex in the Wallenberg syndrome: alteration of the late reflex by lesions of the spinal tract and nucleus of the trigeminal nerve

The orbicularis oculi reflex was studied in nine cases with lateral medullary lesions. Diagnosis of the Wallenberg syndrome was made clinically in seven cases and at necropsy in another. The clinical features of one other case were closely allied to but not typical of this syndrome. An afferent delay of the late reflex on the side of the lesion in the presence of a normal early reflex was seen in all but two cases. In one of the latter, the late reflex was normal and in the other, a comatose patient, the late reflex was totally absent. It was concluded that the neurones of the first order responsible for the bilateral late reflex on unilateral stimulation terminate in the ipsilateral spinal nucleus of the trigeminal nerve without significant crossing over to the same structure on the other side. An afferent delay of the late reflex in the presence of a normal or nearly normal early reflex is consistent with a lateral medullary lesion implicating the spinal tract and nucleus. The Wallenberg syndrome is a common clinical entity showing this abnormality of the orbicularis oculi reflex.

Cell separation on affinity columns: the isolation of immunospecific precursor cells from unimmunized mice (lactoside hapten-lymphocyte receptors-immunology)

We have used affinity columns to isolate from the spleens of unimmunized mice a population of lymphocytes that specifically bind a lactoside hapten. These cells are able to initiate an antibody response to azophenyl-beta-lactoside when transferred to appropriate irradiated recipients.

Electrodiagnostic study of brainstem strokes

The orbicularis oculi reflex elicited by electrical stimulation of the supraorbital nerve was studied in 39 cases with vascular lesions of the brainstem (four mesencephalic, 14 pontine, 13 medullary and eight multilevel), six cases following severe anoxic episodes and two cases of traumatic brainstem lesions. The early reflex (normal latency: 10.6 ± 2.5 msec) was delayed in 20 out of 22 cases with pontine or multilevel brainstem strokes and in all the eight cases of anoxic or traumatic brainstem lesions. The direct (31 ± 10 msec) and consensual (32 ± 11 msec) late reflexes, analogously to the pupillary light reflex, were useful in distinguishing afferent, efferent, and other blocks. In all the seven comatose patients, the late reflex was virtually absent. However, a relatively normal early reflex was present in four of these. The findings of this study indicate that the brainstem conduction altered by vascular and anoxic lesions can be measured simply and objectively by the orbicularis oculi reflex. A delay of the early reflex is relatively specific to pontine lesions. The late reflex is not only altered by brainstem lesions but is also totally depressed in coma, presumably reflecting diffuse suppression in multisynaptic reticular system.