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Biomedical subjects

L Hill

Publications and source records attributed to L Hill.

At least 91 records · Page 5Linked to original sources
PubMed1988

Human granulocyte activity against moxalactam-induced filamentous forms of Pseudomonas aeruginosa.

The purpose of this investigation was to study the kinetics of human granulocyte (polymorphonuclear leukocyte) phagocytosis and bactericidal activity against beta-lactam antibiotic (moxalactam)-induced filamentous bacterial forms of Pseudomonas aeruginosa. Ultrastructural observations of rod and filamentous forms of P. aeruginosa and their interaction with polymorphonuclear leukocytes are presented. Growth of P. aeruginosa 1348A in the presence of 4 micrograms of moxalactam per ml (one-fourth the MIC) resulted in filamentous forms. Phagocytosis of 75Se-radiolabeled filaments was more efficient than that of rods during the first 20 min of the assay; subsequently, phagocytosis of both forms was equal. The polymorphonuclear leukocyte bactericidal activities against both forms, which were standardized to equal bacterial particle and viable-cell counts, were equivalent. Considering the greater size and mass of filaments compared with those of rods, we concluded that filaments are more susceptible to both phagocytosis and killing than are bacillary forms.

Blood Bactericidal Activity↗
PubMed1988

Maternal drug histories and congenital malformations: limb reduction defects and oral clefts.

In a case control study, prescription data were examined for the three months before the last menstrual period and for the first trimester of pregnancy in (a) 115 mothers of children with limb reduction defects, (b) 676 mothers of children with oral cleft, and (c) an equal number of control mothers of normal babies from the same doctor's practice for each case. In the limb reduction study, the study mothers were prescribed more drugs generally although this did not reach statistical significance, nor were there significant differences between study and control mothers for individual groups of drugs. In the oral cleft study, significantly more drugs were prescribed to study mothers in the three months before the last menstrual period, and a similar trend, which did not reach statistical significance, was observed in the first trimester. Anticonvulsant drugs were prescribed significantly more frequently to study mothers during the whole period of the study. A significant association was also demonstrated between oral contraceptives taken in the three months before the last menstrual period and oral cleft, but doubt must remain concerning this relationship; the risk is not well understood and is likely to be nonspecific. A number of other significant associations were identified, although their importance in practice is uncertain in view of the confounding factors that may affect a study of this kind.

Abnormalities, Drug-Induced↗
PubMed1987

The effects of anterior hypothalamic deafferentation on FSH-releasing activity in the intact female hamster.

To study the role of the anterior hypothalamic area (AHA) in the control of the estrous (E) rise of follicle stimulating hormone (FSH), female hamsters were subjected to anterior hypothalamic deafferentation (D) or sham deafferentation (S) on 1500 h of proestrus (P). Serum levels of FSH and luteinizing hormone (LH) were measured by radioimmunoassay and FSH and LH releasing activities measured by bioassay in the anterior (AH) and medial basal hypothalamus (MBH) at several time periods during P and E. D did not affect serum levels of LH, whereas there was an attenuation of FSH levels during P and E. D caused an increase in FSH releasing activity in the AH within 1 h, while LH releasing activity was elevated 8 h after D. In animals with D, LH releasing activity in the MBH was elevated during P and was similar to controls during E. FSH releasing activity in the MBH increased during early E and dropped precipitously by 1400 h of E. Collectively, these data demonstrate dichotomous changes in FSH and LH releasing activities and provide further evidence for dual control mechanisms for these two gonadotropins.

Animals↗
PubMed1987

Lung morphological and permeability changes induced by intravascular coagulation in dogs.

The objectives of this study were to describe the morphological alterations of the pulmonary microvasculature in anesthetized dogs infused intravenously with alpha-thrombin (111-233 NIH U/kg) and to measure the protein reflection coefficient (sigma d), an index of pulmonary vascular permeability to proteins. Quantitative electron microscopy of lung biopsies from a group of four dogs showed an increase in the volume density of the alveolar interstitium and an increase in intravascular fibrin at 30 min after the thrombin infusion. The pulmonary microvascular endothelium was often swollen, blistered, highly vacuolized, or rarefied when close to or in contact with fibrin but appeared normal when not closely associated with fibrin. Fibrin-endothelial interactions often included projections of endothelium surrounding fibrin, the presence of fibrin within endothelial cells, 10- to 15-nm bridges connecting fibrin and endothelium, and disruption of the endothelial plasmalemma in contact with fibrin. Alveolar epithelial cells were unaffected by the thrombin infusion. Pulmonary lymph was collected from an afferent lymphatic to the left tracheobronchial lymph node in a second group of five dogs anesthetized with pentobarbital sodium intravenously. Thrombin increased pulmonary lymph flow by sevenfold and also increased the extravascular lung water-to-bloodless dry lung weight ratio. Left atrial pressure was elevated after thrombin infusion until a filtration-independent state was approached for the calculation of sigma d. Thrombin decreased sigma d from a normal value of 0.62 +/- 0.02 to 0.53 +/- 0.02. Thus thrombin-induced intravascular coagulation in dogs produced focal disruptions of the microvascular endothelium associated with intravascular fibrin and increased the pulmonary vascular permeability to proteins.

Animals↗
PubMed1986

Autoradiographic measurement of tritiated agmatine as an indicator of physiologic activity in Hermissenda visual and vestibular neurons.

[3H]Agmatine (amino-4-guanidobutane) has been shown to be potentially useful for identifying and assessing the ACh sensitivity of specific neurons. Small cationic amines are able to permeate ACh-activated ion channels in sympathetic neurons and vertebrate endplates. Sensory neurons of the photic pathway in the nudibranch mollusc Hermissenda crassicornis are cholinergic and the synaptic interactions between the photic and vestibular systems have been well characterized electrophysiologically. We have therefore tested the feasibility of using autoradiography with [3H]agmatine, (a) to identify known ACh-responsive postsynaptic cells and (b) to examine its ability to serve as an indicator of physiologic activity within the photic and vestibular pathways under conditions of darkness and light stimulation. Scintillation counting revealed that approximately 70% of the radioactivity was associated with the CNS while approximately 30% was found in the processing fluids, indicating that routine glutaraldehyde-osmium fixation and subsequent processing for epoxy embedding allows retention of substantial amounts of the radiolabel. The autoradiographic results consistently demonstrated that the uptake patterns for [3H]agmatine did reflect some of the known neuronal interactions under the experimental conditions of light and dark. The accuracy extended to the second order cells of the optic ganglion and to putative interneurons along the photic tract in the cerebropleural ganglion. Since all the neurons in these pathways are unipolar with their synaptic interactions occurring only at the terminal endings, the radiolabel accumulated in the somata resulted from retrograde axonal transport. In the photic-vestibular pathways, the highest silver grain densities were found over structures (cell bodies or axon tracts) with increased synaptic activity coupled with higher levels of cellular activity (i.e. increased excitatory postsynaptic potentials or increased spontaneous impulse activity). Slightly less label was found in cells which received increased numbers of inhibitory postsynaptic potentials that produced hyperpolarization and a transient cessation of impulse activity under conditions of illumination. Therefore, the uptake levels of [3H]agmatine as revealed by autoradiography appear to reflect not only changes in sensitivity or density of ACh-activated channels but also changes in cellular activity as indicated by increased amounts of retrograde transport. These results represent the first example of the effective use of this radiolabel as an indicator of synaptic activity in invertebrates and in sensory systems.

Agmatine↗
PubMed1986

The concept and reality of shared hospital services.

This decentralized model of sharing health care services, in which a small community hospital through its own initiative has continued to successfully provide services not only to its peer hospitals but to larger secondary hospitals, is a useful example of the effective co-operation and co-ordination between hospitals. Shared Services has successfully evolved from a concept to its present reality as a provider of quality health care services. These programs supply co-ordinated services which both enhance patient care and benefit all hospital staff members. As the merits of both the Respiratory Therapy and Library Services Programs continue to demonstrate themselves, and as the spirit of cooperation between member hospitals continues to grow, the potential for future development of the Shared Services Program is yet to be realized.

Hospital Bed Capacity, 100 to 299↗
PubMed1985

Elective mutism associated with selective inactivity.

In this short case report, elective mutism was only one aspect of a young boy's general pattern of selective non-responding. Behavior management procedures were successfully applied to his inactive nonverbal behavior, as well as his infrequent speech. Nonverbal responses were the easiest to train because they could be physically prompted if he did not respond on his own. Several of the successful treatment techniques were being employed by the mother prior to any intervention.

Behavior Therapy↗
PubMed1985

Interstitial deletion of chromosome 7p detected antenatally.

An interstitial deletion in chromosome 7(p13p15) detected in amniotic fluid cells is presented. After termination, the fetus was noted to have an asymmetrical skull, low set ears, a flattened nose, bifid thumbs and right big toe, pyloric adenomyosis, hypospadias, and simian creases. A brief comparison is made with previously reported cases involving deletions of 7p, including those associated with craniosynostosis.

Chromosome Deletion↗
PubMed1984

Prognostic factors in patients with resected stage I non-small cell lung cancer. A report from the Lung Cancer Study Group.

The authors present prognostic information on recurrence and survival for resected Stage I lung cancer patients with squamous cell carcinoma, adenocarcinoma or large cell carcinoma. The data derive from 392 carefully staged patients and include results from the history and physical examination, preoperative laboratory tests, nature of the surgery, complications, initial pathologic findings following surgical resection, and final pathologic review. A simple multivariate model of recurrence, which is used to classify patients into low, intermediate, and high-risk groups, is based on tumor size and location (T1, T2), histologic type (squamous, nonsquamous/mixed) and nodal status (N0, N1). To model survival, the performance status and the presence of empyema, pneumonia, or wound infection were added to the previous factors. Not all factors associated with increased mortality are associated with increased risk of recurrence, and, in particular, postoperative empyema, pneumonia or wound infections carry an increased risk of death only. Serial measurements of performance status and leukocyte count have the potential for monitoring for increased risk of recurrence and death.

Adenocarcinoma↗
PubMed1983

Bronchial reactivity in asthmatic adults with normal spirometric values.

A comparison was made between airways obstruction produced by exercise. Hyperventilation of cold air, hyperventilation of room air, and inhalation of ultrasonically nebulised distilled water. Seven asthmatics with no airflow obstruction were studied together with seven normal controls. All four provocations produced comparable mean reductions in forced expired volume in one second in the asthmatic patients, but no reduction was obtained in the controls. Whereas exercise, hyperventilation of cold air, and hyperventilation of room air were associated with heat loss from airways, inhalation of nebulised distilled water was not. Inhalation of ultrasonically nebulised distilled water offers a simple additional diagnostic test for asthma. Changes in the osmolality of airway surface liquid may possibly be the common mechanism by which "fog" and hyperventilation produce bronchoconstruction.

Adult↗