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Biomedical subjects

J Morgan

Publications and source records attributed to J Morgan.

At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

Profile of attendance at a maternity hospital emergency room.

BACKGROUND: Direct presentations to secondary care that could have been managed in primary care have been the subject of much study. Social factors may influence the decision to present directly to secondary care services. AIM: To determine the profile and primary care service use of patients attending a maternity hospital emergency room (ER). METHODS: A self-administered, questionnaire based, cross-sectional study was performed over a period of one month. RESULTS: Of 350 patients attending the ER, 343 (98%) completed a questionnaire. Mean age of patients attending was 28 years (range 16-65). Thirty seven per cent were eligible for free medical care and 39% belonged to socio-economic group six. Fifty nine per cent attended outside normal hours, 31% had a female general practitioner (GP) and 38% were referred by a GP to the ER. Twenty eight per cent had seen their GP in the previous three days, 31% had consulted a GP with their current problem and 58% felt "comfortable" or "very comfortable" attending their GP with a gynaecological complaint. CONCLUSIONS: This study indicates that the service is responsible for a considerable workload, with a low level of use of primary care services by those attending.

Adolescent↗
PubMedDate not supplied

The segregation of ON- and OFF-center responses in the lateral geniculate nucleus of normal and monocularly enucleated ferrets.

We have investigated the distribution of ON- and OFF-center responses in the lateral geniculate nucleus of ferrets with normal and abnormal retinal projections. Electrophysiological recordings in normal pigmented animals confirm previous studies on mustelids showing that ON-center responses are found in the anterior, inner parts of laminae A and A1 and OFF-center responses in posterior, outer leaflets. In albino animals, lamina A displays normal patterns of ON/OFF segregation but in lamina A1', which receives an abnormal crossed retinal projection, no consistent patterns of segregation are found. Following monocular enucleation on the day of birth, the uncrossed projection in pigmented ferrets remains expanded across the LGN. Anatomically and physiologically, this projection is segregated into two leaflets: an anterior, inner ON-center leaflet and a posterior outer OFF-center leaflet. We conclude that the persistence of ON/OFF segregation, independent of geniculate location, suggests that self-sorting of retinal input is an important factor in generating the segregation.

Afferent Pathways↗
PubMedDate not supplied

Sequence-specific DNA cleavage by dipeptides disubstituted with chlorambucil and 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid.

Two dipeptides, each containing a lysyl residue, were disubstituted with chlorambucil (CLB) and 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA): DMQ-MA-Lys(CLB)-Gly-NH2 (DM-KCG) and DMQ-MA-beta-Ala-Lys(CLB)-NH2 (DM-BKC). These peptide-drug conjugates were designed to investigate sequence-specificity of DNA cleavage directed by the proximity effect of the DNA cleavage chromophore (DMQ-MA) situated close to the alkylating agent (CLB) inside a dipeptide moiety. Agarose electrophoresis studies showed that DM-KCG and DM-BKC possess significant DNA nicking activity toward supercoiled DNA whereas CLB and its dipeptide conjugate Boc-Lys(CLB)-Gly-NH2 display little DNA nicking activity. ESR studies of DMQ-MA and DM-KCG both showed five hyperfine signals centered at g = 2.0052 and are assigned to four radical forms at equilibrium, which may give rise to a semiquinone radical responsible for DNA cleavage. Thermal cleavage studies at 90 degrees C on a 265-mer test DNA fragment showed that besides alkylation and cleavage at G residues, reactions with DM-KCG and DM-BKC show a preference for A residues with the sequence pattern: 5'-G-(A)n-Pur-3' > 5'-Pyr-(A)n-Pyr-3' (where n = 2-4). By contrast, DNA alkylation and cleavage by CLB occurs at most G and A residues with less sequence selectivity than seen with DM-KCG and DM-BKC. Thermal cleavage studies using N7-deazaG and N7-deazaA-substituted DNA showed that strong alkylation and cleavage at A residues by DM-KCG and DM-BKC is usually flanked on the 3' side by a G residue whereas strong cleavage at G residues is flanked by at least one purine residue on either the 5' or 3' side. At 65 degrees C, it is notable that the preferred DNA cleavage by DM-KCG and DM-BKC at A residues is significantly more marked than for G residues in the 265-mer DNA; the strongest sites of A-specific reaction occur within the sequences 5'-Pyr-(A)n-Pyr-3'; 5'-Pur-(A)n-G-3' and 5'-Pyr-(A)n-G-3'. In pG4 DNA, cleavage by DM-KCG and DM-BKC is much greater than that by CLB at room temperature and at 65 degrees C. It was also observed that DM-KCG and DM-BKC cleaved at certain pyrimidine residues: C40, T66, C32, T34, and C36. These cleavages were also sequence selective since the susceptible pyrimidine residues were flanked by two purine residues on both the 5' and 3' sides or by a guanine residue on the 5' side. These findings strongly support the proposal that once the drug molecule is positioned so as to permit alkylation by the CLB moiety, the DMQ-MA moiety is held close to the alkylation site, resulting in markedly enhanced sequence-specific cleavage.

Antineoplastic Agents↗
PubMedDate not supplied

Cladophialophora bantiana isolated from an AIDS patient with pulmonary infiltrates.

Cladophialophora bantiana causes a rare phaeohyphomycosis, usually manifested by brain abscesses but rarely by skin or pulmonary lesions. It has not been reported as a common colonizer or as a cause of pulmonary symptoms in patients with AIDS. We present a case in which C. bantiana was repeatedly isolated from the sputum of a patient with AIDS having pulmonary infiltrates.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

The breast cancer prevention diet by Dr. Bob Arnot: unscientific and deceptive--a disservice to American women.

The following report is a critical review of the recently published book by NBC's chief medical correspondent, Dr. Bob Arnot, entitled, The Breast Cancer Prevention Diet: The Powerful Foods, Supplements, and Drugs That Can Save Your Life. The review represents the official opinion of the American Council on Science and Health (ACSH), a nonprofit public health education and advocacy group supported by a board of over 250 scientific and policy advisors. The scientists at the ACSH express their profound concern about the misleading, unscientific, and speculative advice that Dr. Arnot offers to women who wish to reduce their risk of breast cancer, i.e., to all women. The ACSH believes, first, that in the absence of sound, peer-reviewed evidence supporting such advice, there is harm in recommending lifestyle modifications for the purpose of preventing breast cancer. The ACSH also believes that a physician (and particularly one in a position of public trust, such as a professional media health expert) should refrain from selling advice based on the twin philosophies that "you can't afford to wait" for the evidence, and that "you can only improve your health" with this diet. Indeed, unproven interventions such as those put forth in this book can have negative effects on both physical and psychological health. The ACSH contacted many of the scientists quoted or cited in Dr. Arnot's book. Some expressed concerns regarding the book's message or the misrepresentation of their work or both. Those physicians affiliated with the Memorial-Sloan Kettering Cancer Center (MSKCC) in New York, while expressing their concerns about the claims made in the book, informed the ACSH that they had been "advised" not to comment on The Breast Cancer Prevention Diet. The MSKCC public relations office acknowledged that the center had serious concerns about the Arnot book and that these concerns had been conveyed to the publisher, Little, Brown and Co., and to Dr. Arnot. The MSKCC representative noted that Dr. Arnot had "graciously" agreed to delete all references to MSKCC from future editions.

Breast Neoplasms↗
PubMedDate not supplied

Evaluation of Graftskin composite grafts on full-thickness wounds on athymic mice.

We used a living bilayered cultured skin replacement to close full-thickness wound defects on the dorsum of athymic mice. The skin replacement is composed of human fibroblasts that condense a bovine collagen lattice; the lattice is then seeded with cultured human keratinocytes. The collagen lattice with fibroblasts serves as a dermal template, and the overlying human keratinocytes form the epidermal component of this composite skin replacement. Twenty-four animals were grafted, and groups of six were killed and biopsied at 6, 15, 30, and 60 days after graft replacement. Twenty-four mice in the control group receiving grafts of fresh, split-thickness, human cadaver skin were biopsied at the same time points. "Take" of all grafts was excellent, with only one graft loss in the 48 mice (one Graftskin graft, at 15 days). Light microscopy revealed that vascular ingrowth into Graftskin occurred rapidly, and discrete dermal and epidermal layers were seen at all time points. Evidence of basement membrane formation was seen at 6 days after grafting by immunohistochemical staining for laminin and by electron microscopic visualization of lamina lucida and lamina densa zones at the dermal-epidermal junction. The results demonstrated that Graftskin formed a structurally complete skin replacement within 1 week of placement on full-thickness wounds on athymic mice, and effective skin coverage was provided for the 60-day observation period after grafting.

Animals↗
PubMedDate not supplied

Absence of differences in platelet dihydroxyphenylalanine (dopa) oxidase polymorphism in health and Duchenne's muscular dystrophy.

Extracts of platelets were subjected to vertical starch gel electrophoresis followed by enzyme staining to further investigate earlier reports of a unique dihydroxyphenylalanine (DOPA) oxidase polymorphism among boys with Duchenne's muscular dystrophy (DMD) and their mothers. This was said to be distinct from those found in healthy controls. Platelets were separated from citrated venous blood by differential centrifugation and checked for purity by phase contrast microscopy. The isolated platelets were disrupted by freeze-thawing in Tris-HC1 buffer (0.02M, pH 8.2), and the resulting platelet extracts were electrophoresed for 15 hours at 130V at 4 degrees C. The starch gels were then sliced and stained with 0.2% DOPA and 0.1% MnCl2. Three electrophoretic patterns of DOPA oxidase activity were found in normal men and women: a single rapidly moving band; a single slowly moving band; and a broad band. These three patterns were also seen in boys with DMD, their mothers, and their fathers. Thus, a unique polymorphism was not found in boys with Duchenne's muscular dystrophy or their carrier mothers.

Adolescent↗
PubMedDate not supplied

Metastatic malignant melanoma arising in a mature ovarian cystic teratoma: a case report and literature review.

Primary malignant melanoma arising inform the ovary is rare, with only 30 cases described in the literature to date. The case reported here occurred in a 19-year-old woman and was rapidly progressive, resulting in death only 37 days following initial presentation. Management of this case is discussed in the context of the other reported cases. Surgery, ranging from an ovarian cystectomy to a radical debulking procedure, has been the main treatment with adjuvant chemotherapy utilized in only 4 of the previous cases. Key problems in management relate to the ability to make the diagnosis at the time of surgery and the overall poor response rates of melanoma to adjuvant chemotherapy.

Adult↗
PubMedDate not supplied

Effects of a 1% chlorhexidine gel on the cariogenic bacteria in high-risk elders: a pilot study.

Root caries in dentate elderly patients is a problem which may be controlled with chlorhexidine. The purpose of this pilot study was to establish the extent and duration of the antimicrobial effects from an intensive regimen of a 1% chlorhexidine gel in institutionalized elders who had experienced high caries activity in the previous year. Stimulated saliva samples from all subjects before treatment produced more than 105 colony forming units/milliliters of Streptococcus mutans (mean: 2.0 x 10(7); s.d.: 2.0 x 10(7)) when diluted and cultured on Mitus Salivarius-bacitracin agar for 48 hours. Findings suggest that daily treatments for 1 week with a 1% chlorhexidine gel can reduce the number of cariogenic bacteria in elderly people for approximately 3 weeks after treatment.

Aged↗
PubMedDate not supplied

Anatomy of the lateral ankle ligaments.

The anatomy of the lateral ankle ligaments that is frequently described in articles and book chapters often lacks the precision of orientation and attachment points. We believe a knowledge of this precise anatomy is important to better reconstruct or repair lateral ligaments. We dissected cadaveric ankles free of skin and soft tissue and made the following measurements: areas of attachments of the anterior talofibular ligament, length and width of the anterior talofibular ligament, and locations of the attachments on the fibula and talus. The same measurements were made of the calcaneofibular and posterior talofibular ligaments. The distance of the calcaneofibular calcaneal attachments from the subtalar joint as well as the angle in the sagittal plane with the fibula was determined. We then used these anatomic attachments of the ligaments to make comparisons with the Watson-Jones and modified Elmslie reconstructions. Our results enable us to suggest a more anatomic placement for ligaments in a reconstruction.

Ankle Joint↗
PubMedDate not supplied

Determination of pesticides in composite dietary samples by gas chromatography/mass spectrometry in the selected ion monitoring mode by using a temperature-programmable large volume injector with preseparation column.

Use of a temperature-programmable preseparation column in the gas chromatographic (GC) injection port permits determination of a wide range of semi-volatile pesticides including organochlorines, organophosphates, triazines, and anilines in fatty composite dietary samples while reducing sample preparation time and solvent consumption. Dietary samples are mixed with diatomaceous earth and are Soxhlet-extracted with an azeotropic solution of hexane and acetone. Sample preparation uses liquid-liquid partitioning over diatomaceous earth followed by normal phase chromatography over partially deactivated alumina. The final cleanup step occurs in a preseparation column in the GC injector, which is able to perform splitless transfer of the analytes to the analytical column and purge 99% of the high molecular weight residue. Detection is performed by GC/mass spectrometry (MS) in the selected ion monitoring mode. Method detection limits were at or below 2 ng/g for 24 of 35 pesticides studied, with recovery between 70 and 125% for 27 pesticides in samples fortified at 10 ng/g. Recovery was not dependent on fat content when measured in laboratory fortified samples containing 1, 5, and 10% fat by weight. Precision over multiple injections was acceptable, with a relative standard deviation of 2.6-15% for 25 analytes.

Aluminum Oxide↗