Clinical model for management of pulmonary embolism.
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Fibrin Fibrinogen Degradation Products↗
Biomedical subjects
J F Whitney
Publications and source records attributed to J F Whitney.
Exercise limitation testing.
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Exercise Test↗
Obstructive sleep apnea presenting as acute delirium.
Obstructive sleep apnea syndrome (OSA) has not been previously reported as a cause of acute delirium. A patient who presented to the emergency department with acute delirium according to DSM-IIIR criteria was noted to have an abnormal respiratory pattern with periods of apnea associated with oxygen desaturation. The observation that the patient had episodes of apnea while sleeping led to the suspicion that this patient had OSA, and formal polysomnography confirmed the diagnosis. Other causes for acute delirium were ruled out. The delirium resolved after the OSA was treated.
Acute Disease↗
Transferrin receptor expression in nonsmall cell lung cancer. Histopathologic and clinical correlates.
BACKGROUND: In the search for tumor-related antigens with survival-predictive value, previous studies have yielded varied conclusions regarding the expression of one such antigen, the transferrin receptor in lung cancer. The goal of this study was to define the frequency of expression of transferrin receptor in lung cancer specimens and gather preliminary data regarding the prognostic value of this tumor-related antigen. METHODS: Tissue immunoreactivity was studied with a murine monoclonal antibody to transferrin receptor in patients with nonsmall cell lung cancer who underwent surgical resection at the Medical Center Hospital of Vermont during the period from January, 1988, to May, 1991. RESULTS: The study group consisted of 32 patients (21 males and 11 females) with an average follow-up length of 27 months (standard deviation of 16 months). There were 17 patients with adenocarcinoma, 14 with squamous cell carcinoma, and 1 with large cell carcinoma. At the end of data accumulation, a total of 16 deaths had been recorded (8 with squamous cell, 8 with adenocarcinoma). Normal lung tissue did not stain for transferrin receptor; however, 13 of 17 (76%) adenocarcinomas, 13 of 14 (93%) squamous cell carcinomas, and the 1 large cell carcinoma stained positively for transferrin receptor. Staining for transferrin receptor was graded according to pattern and intensity and categorized as absent-weak or strong. Survival analysis was performed to evaluate patient outcome based on a variety of clinical and experimentally determined characteristics. Groups based on N-status (N0 vs. N1 + N2, P = 0.08), stage (Stage 1 vs. Stage 2 + 3 P = 0.13), age (younger than 60 vs. 60 years or older, P = 0.09), and transferrin receptor staining (absent-weak vs. strong, P = 0.14) achieved nearly significant differences in survival. Further analysis of the differences in survival for groupings based on transferrin receptor staining found that these differences in survival reached significance for patients with larger tumors (T2 or T3, P = 0.02). CONCLUSIONS: Transferrin receptor is expressed in the majority of lung cancers and the presence of transferrin receptor in nonsmall cell lung cancers may be an indicator of poorer prognosis in certain groups of patients.
Adenocarcinoma↗
Bilateral projections from the parabigeminal nucleus to the superior colliculus in monkey.
We examined the distribution of labeled neurons in the parabigeminal nucleus of the monkey following injections of retrograde fluorescent tracers into the superior colliculus. The extent of the visual field representation included in the injection site was assessed from the location of labeled cells in striate cortex. The results suggest a rough topographic organization of the parabigeminal nucleus, with the lower quadrant represented anteriorly and the upper quadrant posteriorly. We also found bilateral projections from the parabigeminal nucleus to both superior colliculi, but the crossed projection appeared to terminate only in that part of the colliculus where the vertical meridian is represented. Parabigeminal cells with a crossed projection were larger than those projecting to the ipsilateral colliculus. The results suggest that the organization of the monkey's parabigemino-tectal system is fundamentally similar to that of many other vertebrates.
Amidines↗
Method for stable intracellular recordings of spinal alpha-motoneurons during treadmill walking in awake, intact cats.
A method is described for recording from spinal alpha-motoneurons, which are identified according to muscle innervated, with an intracellular microelectrode during treadmill walking in awake, normally respiring, intact, adult cats. The procedure involves the implantation of an orthopedic-style spinal unit, the training of the subject to locomote on the treadmill with the lumbar region restrained, and the micropipette recording of motoneurons through a small laminotomy.
Animals↗
Electrotonic parameters of cat spinal alpha-motoneurons evaluated with an equivalent cylinder model that incorporates non-uniform membrane resistivity.
The membrane voltage transients in response to constant intracellular current steps were analyzed in cat spinal alpha-motoneurons, using an equivalent cylinder model extended to include spatial non-uniformity in membrane resistivity. The main hypothesis was that the soma membrane resistivity did not differ significantly from the dendritic membrane resistivity. Evidence was found that the uniform-resistance cylinder model cannot be applied to motoneurons on the basis of inconsistencies in calculations of electrotonic length. Assuming a constant membrane capacitance, the membrane resistivity of the dendrites was found to be 500 times that of the soma. We conclude that there is a considerable difference in the membrane resistivity between the soma and dendrites of motoneurons, and that uniform-resistance models should not be applied to spinal alpha-motoneurons.
Animals↗
Contraction properties and motor nucleus morphology of the two heads of the cat flexor carpi ulnaris muscle.
Previous studies have examined the isometric contraction properties of the two heads of the cat flexor carpi ulnaris acting as a single unit. In this study, the contraction properties and fiber architecture of each head of the flexor carpi ulnaris were determined separately and related to previous reports on the histochemical characteristics of this muscle. The morphology of retrograde-labeled motor nuclei for the two heads of the muscle was also examined. The humeral head had a significantly longer contraction time (48 msec) than the ulnar head (36 msec) as well as a significantly lower tetanic fusion frequency (28 Hz vs. 35 Hz). The maximum tetanic tension per gram of muscle tissue was 71% greater in the ulnar head. Motoneurons of the flexor carpi ulnaris formed a column 12 mm long and 0.5 mm wide in the center of the ventral grey in spinal segments C8 and T1. The ulnar head had alpha-motoneurons with greater soma diameters than those in the humeral head. The smaller soma diameter, slower contraction time, and weaker contraction in the humeral head correlate with the preponderance of oxidative-metabolic muscle fiber types found in the humeral head by other workers. These correlations suggest that the humeral head plays a major role in maintaining a sustained antigravity tension that prevents the wrist from buckling during standing.
Animals↗
Pentobarbital and halothane hyperpolarize cat alpha-motoneurons.
The effect of anesthetics on the membrane potential of spinal alpha-motoneurons was studied in awake-intact cats that were sequentially anesthetized with either halothane or pentobarbital. Pentobarbital (35 mg/kg) and halothane (5%) both induced a 5 mV hyperpolarization and a reduction in spontaneous synaptic activity of motoneurons. We suggest that a reduction in the urinary EPSP frequencies contributes to the hyperpolarization and the membrane potential criterion of acceptable impalements of motoneurons in awake-intact preparations should be 5 mV more depolarized than that in anesthetized preparations.
Action Potentials↗
Effect of medial preoptic lesions on sexual behavior of female rats is determined by test situation.
The sexual behavior of female rats with bilateral lesions in the medial preoptic area (MPOA) was examined in two testing conditions. In the first condition, in which the female could not leave the vicinity of males (no-exit test), lordosis quotients (LQs) were elevated in relation to baseline levels. In the second condition, in which the female could control her proximity to males (exit test), LQs were not different from control levels, and experimental subjects permitted fewer copulatory contacts, exhibited less frequent solicitational behavior, and spent less time with males than the controls did. These findings suggest that the higher LQs seen in no-exit tests as a result of MPOA damage are not due to a lesion-induced potentiation in the females' preference to engage in sexual contacts with males.
Animals↗
Effects of vagino-cervical stimulation upon sociosexual behaviors in female rats.
The role of vagino-cervical stimulation in the control of feminine copulatory behavior in the behaviorally estrous rat was examined in a complex environment that allowed the test female to pace her contacts with sexually active males, sexually passive males and ovariectomized females. Manipulations of vagino-cervical stimulation by administration of a topical anesthetic or by probing with a glass rod, immediately before testing in the complex environment, did not significantly alter any aspect of behavior in behaviorally estrous females. Transection of the pelvic nerve increased the number of intromissions and ejaculations that the females received and increased the amount of time that the females spent with the sexually active males. The present results implicate the pelvic nerve in the modulation of motivation for coital contacts in the female rat.
Animals↗
The effect of pregnancy and stress on the onset of placentophagia in Long-Evans rats.
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Animals↗
Placenta on pups' skin accelerates onset of maternal behaviour in non-pregnant rats.
Previous research has indicated that virgin rats (Rattus norvegicus) behave maternally (sensitize) more rapidly in close proximity with pups. Since both parturient rats and a large percentage of virgin rats avidly consume placenta, we tested whether placenta and amnionic fluid, pups and therefore hasten the onset of maternal behaviour. The results indicated that the procedure indeed shortened the maternal sensitization latency. Furthermore, this effect was not due to the wetness of the pups, to the presence of placenta in the cage, or to the adults having previously ingested placenta. Other attractive ingestibles applied to the pups' skin produced an intermediate, but not significant, shortening of the maternal sensitization latency.
Animals↗