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Biomedical subjects

C Morgan

Publications and source records attributed to C Morgan.

At least 181 records · Page 10Linked to original sources
PubMed1987

Trauma-induced human endometrial prostaglandin concentrations.

Controversy still continues concerning the factors controlling endometrial prostaglandin concentrations measured under different circumstances. In this study an attempt was made to remove serial samples of normal human endometrium and standardise 4 different short incubation periods at room temperature before snap-freezing the tissue. No significant difference was found in the concentrations of PGE2 and PGF2 alpha, or PGE2/PGF2 alpha ratio, of the series of specimens with the shortest incubation (42.7 seconds) compared with the longest (93.1 secs). The most likely explanation for this is that trauma-induced prostaglandin production is such a rapid process that it is generally complete within less than 30 seconds at room temperature. As reported in previous studies, a significant correlation was found between PGE2 and PGF2 alpha concentrations in some specimens. Large and significant variations in concentration of prostaglandins were found between individuals which were partly accounted for by variations in stage of the menstrual cycle at the time of collection.

Biopsy↗
PubMed1987

Comparison of computer-assisted learning with tutorial teaching in a group of first-year dental students.

Two identical groups of first-year dental students were instructed in the pathology of dental caries and periodontitis using computer-assisted learning (CAL) or tutorial teaching (TT). A cross-over arrangement, in which the first group was taught about dental caries by CAL and periodontitis by TT and the second group in the reverse order, allowed comparison of the two methods. The comparison included a knowledge test and completion of a questionnaire. CAL and TT were equally effective as far as acquisition of knowledge was concerned. Students felt pressurized with CAL and had problems with note-taking. They liked a teacher to be present. Nevertheless, CAL was an acceptable method of instruction and was more economical, in terms of staff involvement, than TT.

Computer-Assisted Instruction↗
PubMed1987

Re-evaluation of the sublocalization of esterase D and its relation to the retinoblastoma locus by in situ hybridization.

In situ hybridization of a cDNA probe for the esterase D gene (ESD) was carried out on human chromosomes. The probe hybridized most strongly to 13q14.2 and 13q14.3. This observation raises doubts concerning the most recently published assignment of ESD to 13q14.1. A deletion in an individual with retinoblastoma was reported to separate the closely linked ESD and retinoblastoma (RB1) loci, placing ESD proximal to RB1. Quantitative in situ hybridization studies of this deletion do not confirm this interpretation. Rather, they suggest that ESD is missing from the deleted chromosome 13 and duplicated on the normal homolog. From these findings, we conclude that the deletion in this individual cannot be used to determine the orientation nor the sublocalization of ESD and RB1 within the 13q14 region.

Carboxylesterase↗
PubMed1987

An attempt to prevent anaphylaxis by aerosolized antigen in guinea pigs.

In an attempt to provide an alternative and safer technique of specific hyposensitization for those patients for whom the conventional treatment presents a high risk for anaphylaxis, we used a guinea pig model for extracorporeal hyposensitization. We sensitized three groups of guinea pigs with an olive pollen extract. Two of the groups were sensitized before removal of their buffy coat and the third group was sensitized after the removal of their buffy coat. The buffy coat cells were incubated with the same antigen and intracardially reinjected into their respective donors. Subsequent challenges by aerosolized antigen and intracardiac injections were performed. We did a basophil degranulation on random samples of buffy coat of tested and control animals. We skin tested the animals and we examined the histopathology of their lungs. The animals reinjected with the incubated buffy coat prior to sensitization showed a greater protection from aerosolized antigen and the onset of their anaphylactic symptoms was significantly delayed when compared with controls. The results of basophil degranulation studies showed that animals sensitized before removal of their buffy coat had approximately a threefold increase of degranulated basophils as compared with animals that were sensitized after removal of buffy coat and approximately a fourfold increase when compared with controls. This degranulation did not affect the specific skin test. Histopathologic observations did not reveal any characteristics typical of anaphylaxis.

Aerosols↗
PubMed1986

Expression and structure of the human NGF receptor.

The nucleotide sequence for the human nerve growth factor (NGF) receptor has been determined. The 3.8 kb receptor mRNA encodes a 427 amino acid protein containing a 28 amino acid signal peptide, an extracellular domain containing four 40 amino acid repeats with six cysteine residues at conserved positions followed by a serine/threonine-rich region, a single transmembrane domain, and a 155 amino acid cytoplasmic domain. The sequence of the extracellular domain of the NGF receptor predicts a highly ordered structure containing a negatively charged region that may serve as the ligand-binding site. This domain is conserved through evolution. Transfection of a full-length cDNA in mouse fibroblasts results in stable expression of NGF receptors that are recognized by monoclonal antibodies to the human NGF receptor and that bind [125I]NGF.

Amino Acid Sequence↗
PubMed1986

The distribution within the spinal cord of visceral primary afferent axons carried by the lumbar colonic nerve of the cat.

Horseradish peroxidase taken up by the sensory axons in the lumbar colonic nerves in 5 cats was observed in the dorsal root ganglia and in the spinal cord in segments L1 through L5. Reaction product was observed in Lissauer's tract, the dorsal columns and laminae I, V, VII and X in a pattern typical of visceral primary afferents from other nerves. A small number of preganglionic neurons were also labeled.

Afferent Pathways↗
PubMed1986

The distribution and morphology of parasympathetic preganglionic neurons in the cat sacral spinal cord as revealed by horseradish peroxidase applied to the sacral ventral roots.

Parasympathetic preganglionic neurons in the sacral parasympathetic nucleus (SPN) of the cat were studied by applying horseradish peroxidase (HRP) to the sacral ventral roots. The results were compared to data from earlier experiments in which these same neurons were labelled by HRP applied to the pelvic nerve at a point much further from the spinal cord. The present experiments have shown. The total number of neurons in the SPN determined by ventral root labelling is equal to the number obtained by pelvic nerve labelling. This indicates that virtually all SPN neurons send their axons into the pelvic nerve. More extensive dendritic projections from SPN neurons were revealed than in the pelvic nerve experiments. In particular, a strong dendritic projection extended within the lateral marginal zone of the dorsal horn close to Lissauer's tract and horizontal dendrites projected well into the contralateral gray matter, some reaching the contralateral sacral parasympathetic nucleus. The neurons labelled via any one ventral root were all contained within a region equal in length to one spinal segment but shifted rostrally by a small amount. Thus, no evidence was obtained for a long intraspinal pathway in which axons of spinal cord neurons entered ventral roots many segments away from their somata.

Animals↗
PubMed1986

The spinal distribution of sympathetic preganglionic and visceral primary afferent neurons that send axons into the hypogastric nerves of the cat.

The spinal distribution of sympathetic preganglionic neurons (PGN) and visceral primary afferent neurons sending axons into the hypogastric nerve of the cat has been studied with HRP tracing techniques. After application of HRP to the cat hypogastric nerve, labeled PGN were identified in segments L2-L5. Most of these neurons were oriented transversely and were divided approximately equally between two nuclei: the principal nucleus and the intercalated nucleus. Cells were distributed in clusters at 160-361-microns intervals along the length of the cord. Sensory neurons were labeled in dorsal root ganglia from T12 to L5. Central axons of these visceral afferents were observed in the medial half of Lissauer's tract from T13 to L7. Afferent axon collaterals extended through lamina I on both sides of the dorsal horn but were most prominent on the lateral side, where they continued into lateral lamina V and VII, often overlapping the dorsal dendrites of PGN in this region. Labeled afferent projections exhibited a periodic distribution in lamina I with clusters of axons occurring at 235-343-microns intervals in the rostrocaudal axis. The central projection of hypogastric nerve primary afferents was qualitatively similar to the distribution of visceral afferent projections at other levels of the spinal cord.

Animals↗
PubMed1985

Acquired immunodeficiency syndrome in New York City. Evaluation of an active surveillance system.

In January 1983, the New York City Department of Health initiated an active surveillance program for acquired immunodeficiency syndrome (AIDS) in 19 hospitals and a modified-active surveillance program in the remaining 69 hospitals. We reviewed hospital laboratory and autopsy records in 12 active surveillance hospitals and three modified-active surveillance hospitals six months later. Patients who had opportunistic diseases characteristic of AIDS diagnosed in 1982 (before active surveillance) and 1983 (after implementation of active surveillance) were matched against health department AIDS surveillance reports. For the 16 months we evaluated, 96% of patients identified with AIDS in the 12 active surveillance hospitals and 100% of those in the three modified-active surveillance hospitals had been reported to the health department. The delay between diagnosing a case and reporting it to the health department significantly decreased between 1981 and the first six months of 1983 in all hospitals. The proportion of cases reported within one month of diagnosis increased from 45% to 69% during this period. We conclude that the current surveillance program for AIDS in New York City is effective and that case reporting is sufficiently complete for accurate analysis of disease trends.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Nonexpression of a major heat shock gene in mouse plasmacytoma MPC-11.

The major heat shock gene coding for a 68,000-dalton protein was found to be silent in mouse plasmacytoma MPC-11 in both control and stressed cells. The block appears to be at the level of transcription, although RNA processing or instability has not been ruled out. It is not caused by a major deletion or rearrangement of the gene.

Animals↗
PubMed1984

Patient access to medical records--from issue to law. Part I: An historical perspective.

The growing interest of the individual in gaining control of his destiny, reflected over the past two decades in the consumer movement, has run a course parallel to the establishment of patient rights in consumption of health services. The desire to know the particulars of his health care is one such area of consumer interest, and across the nation, this desire to know is fast becoming an absolute right to know. Although in some states this right has become established through the courts, it would appear to be more satisfactorily ensured by means of specific legislation. The state of Maryland has enacted a statute which guarantees the patient access to his own medical record information: this process is surveyed as a means of expanding the evolutionary process from issue to law. Part II of this article, which will appear in the next issue of JAMRA provides an action model for states in which similar change is sought.

Civil Rights↗