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Biomedical subjects

L B Minor

Publications and source records attributed to L B Minor.

41 records · Page 3Linked to original sources
PubMed1984

Monosynaptic activation of long descending propriospinal neurons from the lateral vestibular nucleus and the medial longitudinal fasciculus.

In decerebrate cats long descending propriospinal (LDP) neurons were recorded extracellularly in the cervical enlargement. They were identified antidromically by spinal cord stimulation at the L1-L2 level. Inputs to these cells were tested by stimulating the medial longitudinal fasciculus (MLF) 5 to 6 mm rostral to the obex, the lateral vestibular nucleus (LVN), the upper MLF 1 mm caudal to the trochlear nucleus, and the medial vestibular nucleus (MVN), all on the ipsilateral side. Action potentials were elicited in 44% (64/144) of LDP neurons in the ventral horn (laminae VII, VIII) at a segmental latency of 1 ms or less following brain stem stimulation. This was considered to be a monosynaptic latency. The most effective stimulation sites were the MLF and the LVN. MLF stimulation accounted for about two-thirds of the monosynaptically elicited action potentials and LVN for about one-third. Another 22% of LDP neurons responded at longer latencies, but some of those responses may also have been monosynaptic. Stimulation of the upper MLF and the MVN were much less effective, indicating that the MLF input was predominantly from fibers originating in the medullary and/or pontine reticular formation.

Animals↗
PubMed1983

Fungal sepsis in surgical patients.

Records of 65 surgical patients with positive fungal blood cultures were reviewed to address risk, overall mortality, and treatment. Negative urine cultures did not rule out sepsis. Staphylococcus epidermidis sepsis was present in 27 (42%) of the patients. In 70% of whom it occurred before or during fungemia. Increased mortality correlated with the use of multiple antibiotics, antibiotic use for prolonged periods, and with associated bacterial sepsis. Stopping antibiotic therapy did not reduce mortality. Amphotericin B reduced mortality in patients with dissemination, indicating that it is the treatment of choice for disseminated fungemia and that antibiotic therapy should not be discontinued when concomitant bacterial sepsis is present.

Adolescent↗
PubMed1980

Proton magnetic resonance study of the histidines in hemerythrin and chemical identification of the nonligand histidines.

Three non-iron-liganded histidines have been studied in methemerythrin azide monomers from Pascolopsis gouldii by 250-MHz proton correlation nuclear magnetic resonance (NMR) spectroscopy. Four of the seven histidines in the protein are not observed because of paramagnetic broadening by the coordinated iron; neither are they observed as contact or pseudocontact shifted resonances. The NMR titration of the three free histidines establishes them as normal histidines with pK' values of 7.00 +/- 0.03 and Hill coefficients of 0.90, 0.81, and 0.81 +/- 0.03. The chemical shift of the protonated and neutral histidines is normal, and the bandwidth of the resonance absorption is 5 Hz. A pH-dependent reversible transition in the chemical shift of the histidine C(2)H occurs at pH 6.5; above this pH the three protons occur as a singlet but break into three singlets of different chemical shift at acid pH values. Two of the three "free" histidines have been identified by their susceptibility to photooxidation as His-82 and His-34.

Animals↗
PubMedDate not supplied

Relationship between time- and frequency-domain analyses of angular head movements in the squirrel monkey.

We used the three-dimensional magnetic search-coil recording technique to study the range of active angular head movements made by squirrel monkeys. There were two goals in this study: (1) to determine the range of angular velocities and accelerations as well as the bandwidth and other frequency characteristics of active head movements and (2) to compare analyses of transients of velocity and acceleration that are studied by residual analysis, Fourier transform, and wavelet transform of the head velocity signal. The residual analysis showed that the shape and duration of the transients affected the bandwidth. During the time after the head had begun to accelerate, the frequency content of the head movement extended into the range of 6 to 12 Hz. When considering all three planes of rotation, approximately 75% of the transients had peak acceleration between 2,000 and 10,000 deg/s(2) and a peak velocity of 50 to 400 deg/s. A peak acceleration of >10,000 deg/s(2) was recorded in 10% of the transients. These findings indicate that active head movements in squirrel monkeys cover a higher range of frequencies, accelerations, and velocities than have typically been used in previous eye-movement and neuronal studies of the reflexes that control gaze. We further conclude that the choice of a method for analyzing transient, time-varying biological signals is dependent on the desired information. Residual analysis provides detailed resolution in the time domain, but estimation of the frequency content of the signal is dependent on the portions selected for analysis and the choice of filters. Fourier transform provides a representation of the power spectrum in the frequency domain but without any inherent temporal resolution. We show that the wavelet transform, a novel method as applied to the signal analysis goals of this study, is the most useful technique for relating time- and frequency-domain information during a continuous signal.

Acceleration↗