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Biomedical subjects

J Jackson

Publications and source records attributed to J Jackson.

At least 163 records · Page 9Linked to original sources
PubMed1994

The effect of user fees on the utilization of family planning services. A clinical study.

A new fee structure was introduced to the Advanced Training and Research in Fertility Management Unit in 1992. The study looked at the effect of the new fees on attendance and the choice of contraceptive methods through an examination of clinical records and a questionnaire survey. There was a decline in attendance of roughly 28 per cent between 1992 and 1993. The decline affected mainly new clients and those who accepted injectables. A reduction in the price of injectables is suggested since the fee for this short-term method is more in line with those charged for long-term and permanent methods.

Family Planning Services↗
PubMed1994

Hydrogel embolic agents. Theory and practice of adding radio-opacity.

RATIONALE AND OBJECTIVES: Spheres of hydrogel have been developed as embolic material with the ability to incorporate radio-opaque materials. To optimize particle design for radiographic or fluoroscopic visualization, we have examined the theoretical determinants of particle contrast. In addition, loaded hydrogel particles were tested in a rabbit model. METHODS: Computer simulations of particle subject contrast were examined regarding particle composition, particle size, patient thickness, and x-ray beam kilovoltage. Embolizations in the rabbit kidney were used to test the practical aspects of the materials. RESULTS: Tantalum and tungsten offer some theoretical and practical advantages over other materials. With this particular hydrogel preparation, contrast material loading was limited to 20% of the volume as loaded contrast agent. The soft particles passed through catheters as small as 3 French; they were usually injected as a suspension of saline/contrast material. Tantalum/hydrogel particles as large as 2 mm could be forced through the 140 cm/3-Fr catheter with a guide wire. CONCLUSIONS: Radio-opacity of embolic material should add an element of control in embolization procedures that is lacking with the current agents. The heavy metals, tungsten and tantalum, are suitable additives for radiopaque material for hydrogel emboli. The input relationship appears predictable with computer monitoring techniques. Initial results in a study of these radiopaque particles are very encouraging. Further studies are underway to evaluate the long-term effects in renal and hepatic circulations.

Acrylic Resins↗
PubMed1993

Comparative analysis of the locus control region of the rabbit beta-like gene cluster: HS3 increases transient expression of an embryonic epsilon-globin gene.

The rabbit homolog to the locus control region (LCR) of the human beta-like globin gene cluster was isolated, and long segments containing the DNase I hypersensitive sites (HS) were sequenced. The order and spacing of HS4, HS3, HS2 and HS1 are conserved between rabbit and human. Alignment of these sequences with their homologs from human, goat, and mouse shows that very long segments of DNA match between species, for over a thousand base pairs on either side of the previously identified functional cores, indicating that some important functions are found outside the cores. The activity of rabbit HS2 and HS3 was tested by attaching each to a novel reporter gene constructed by inserting the luciferase coding region into the rabbit epsilon-globin gene. In contrast to previous reports showing no effect of human or mouse HS3 on transient expression, both the rabbit HS2 and HS3 DNA fragments separately increased transient expression from the epsilon-luciferase hybrid gene and expression from stably integrated constructs in K562 erythroleukemia cells.

Animals↗
PubMed1993

Management of cytogenetic data in multi-center leukemia trials.

This paper provides methods for storing and retrieving cytogenetics data, which must reside jointly in a reference laboratory and in a data co-ordinating center. The major piece of data is the character string that uses the International System for Human Cytogenetic Nomenclature. Simple and complex data retrieval, using Statistical Analysis System (SAS) functions INDEX and SUBSTR, are illustrated. Use of the methods of this paper can save considerable costs in setting up cytogenetic data systems compared with other proposed systems which have come to the authors' attention.

Child↗
PubMed1993

Evaluation of a gastric delivery system for iron supplementation in pregnancy.

The present investigation was undertaken to assess the efficacy of oral iron supplementation during pregnancy by using a gastric delivery system (GDS). Three hundred seventy-six pregnant women between 16 and 35 y of age and 14 and 22 wk gestation were selected if mild anemia was present (hemoglobin concentration 80-110 g/L). The participants were randomly assigned to one of three study groups given no iron, two FeSO4 tablets (100 mg Fe) daily, or one GDS capsule (50 mg Fe) daily. Blood was obtained initially and after 6 and 12 wk for measurement of red blood cell and iron indexes, including serum transferrin receptor. There was a significant and comparable improvement in hematologic and iron-status measurements in the two groups of women given iron whereas iron deficiency evolved in women given no iron supplement. We conclude that by eliminating gastrointestinal side effects and reducing the administration frequency of an iron supplement to once daily, a GDS offers significant advantages for iron supplementation of pregnant women.

Administration, Oral↗
PubMed1993

False aneurysm of the pulmonary artery associated with cardiac catheterisation.

A false aneurysm of the pulmonary artery developed in a 59 year old woman as a complication of right-sided cardiac catheterisation. This rare, life-threatening condition was successfully treated with coil embolisation of the feeding artery. Cardiologists and intensive care doctors should be aware of the possibility of the formation of false aneurysms of the pulmonary artery after Swan-Ganz and other right heart catheterisation. Appropriate therapy could be life-saving.

Aneurysm, False↗
PubMed1993

On the morality of deception--does method matter? A reply to David Bakhurst.

Does it signify morally whether a deception is achieved by a lie or some other way? David Bakhurst has challenged my view that it can signify. Here I counter his criticisms--firstly, by clarifying the terminology: What counts as a lie? Secondly, by exploring further what makes lying wrong. Bakhurst maintains that lying is wrong in that it infringes autonomy--and other deceiving stratagems, he says, do so equally. I maintain that lying is wrong in that it endangers trust--and other types of deceiving stratagems do not do so equally. Lying to patients, I contend, is an abuse of their trust. Other forms of their intentional deception need not be so, although, in our autonomy-minded culture, they are likely to be so.

Beneficence↗
PubMed1993

Positive and negative regulatory elements of the rabbit embryonic epsilon-globin gene revealed by an improved multiple alignment program and functional analysis.

The epsilon-globin genes of mammals are expressed in early embryos, but are silenced during fetal and adult erythropoiesis. As a guide to defining the regulatory elements involved in this developmental switch, we have searched the sequences of epsilon-globin genes from different mammals for highly conserved segments. The search was facilitated by the development of a new program, called yama, to generate a multiple alignment of very long sequences using an improved scoring scheme. This allowed us to generate a multiple alignment of sequences from a more divergent group than previously analyzed, as demonstrated here for representatives of four mammalian orders. In parallel experiments, we constructed a series of deletion mutations in the 5' flank of the rabbit epsilon-globin gene and tested their effect on an epsilon-globin-luciferase hybrid reporter gene. These results show that 121 bp of 5' flank, containing CACC, CCAAT and ATA motifs, is sufficient for expression in erythroid K562 cells. Both positive and negative cis-acting control sequences are located between 218 and 394 bp 5' to the cap site, in a region previously proposed to be a silencer. The positive regulatory sequence contains conserved binding sites for the nuclear protein YY1 adjacent to another highly conserved sequence. The negative element contains a conserved sequence followed by a purine-rich segment. This analysis maps the upstream control sequences more precisely and points to a very complex regulatory scheme for this gene.

Animals↗
PubMed1993

Hyphema.

Hyphema is a potentially sight-threatening sequela of blunt trauma. Delayed healing time, poor visual outcome, and complications such as corneal blood staining, anterior and posterior synechiae, increased intraocular pressure, and glaucomatous optic atrophy are most often associated with hemorrhage filling more than one half of the anterior chamber. Rebleeds are most likely 3 to 5 days following injury, in children, in blacks (particularly if they have sickle cell disease), and in persons who have ingested aspirin or other antiplatelet compounds. Treatment of hyphema is controversial, and medical therapy (antibiotics, cycloplegics, steroids, aminocaproic acid) should be tailored to suit the needs of each case. Intraocular pressure-reducing medications may be required if there is significant elevation of IOP. The affected eye should be protected with a shield, and follow-up examinations should be conducted as necessary. Both the anterior and posterior eye should receive careful assessment.

Eye Injuries↗
PubMed1993

Structure and homology of human C1q receptor (collectin receptor).

In this paper we report partial amino acid sequence for C1q receptor (C1qR). The N-terminal amino acid sequence of isolated C1qR and the sequences of peptides obtained by V8/trypsin digestion show a high degree of similarity to the cDNA-derived amino acid sequence of a human protein which was initially reported as a component of RoSSA and subsequently as calreticulin. This sequence in turn shows homology with Onchocerca volvulus antigen (RAL-1) and B50 murine melanoma antigen. A component of approximately 53,000 MW, isolated from human spleen, was found to have identical mobility on SDS-PAGE to C1qR and identical N-terminal sequence, but a different overall charge. Human antibodies from Sjögren's syndrome patients did not recognize C1qR, but showed positive reaction with the purified 53,000 MW component from spleen. Rabbit antibodies against denatured C1qR, in contrast, recognized both C1qR and the purified 53,000 MW component. The 53,000 MW spleen component thus has an identical N-terminal sequence to calreticulin, and to the reported RoSSA component, and is recognized by antibodies in Sjögren's syndrome sera. The data obtained indicate that C1qR and the reported calreticulin/RoSSA component are similar but not identical molecules, which belong to the same protein superfamily.

Agglutination↗
PubMed1992

Low-molecular weight B cell growth factor (BCGF-12KD) as an autocrine growth factor in B cell chronic lymphocytic leukemia.

The role of cytokines in the growth and spreading of human hematologic malignancies has been underlined in recent years. Here we report evidence that a human 12-kDa B cell growth factor (BCGF-12KD) may function as a growth stimulatory factor in B cell chronic lymphocytic leukemia (B-CLL). First, recombinant BCGF-12KD induced dose-dependent DNA synthesis in neoplastic B cells of four B-CLL patients tested. Second, seven different B-CLL clones secreted a BCGF-12KD-like product that accounted for their proliferation. A neutralizing monoclonal antibody (mAb; Ac8) directed against a BCGF-12KD synthetic peptide inhibited the spontaneous growth of the leukemic B cells. The same mAb blocked DNA synthesis in normal tonsillar B lymphocytes induced by the culture supernatant of spontaneously proliferating B-CLL cells. Finally, BCGF-12KD mRNA was expressed in freshly isolated (two of three patients) as well as in vitro proliferating B-CLL cells (three of three patients). These findings strongly suggest that BCGF-12KD can modulate the growth of B-CLL cells in vivo as well as in vitro. They may offer significant insights into the biology of this frequent B lymphoproliferative disorder.

Adult↗
PubMed1992

Chemical and immunological testing for faecel occult blood: a comparison of two tests in symptomatic patients.

An established chemical faecal occult blood test (Haemoccult prepared without rehydration) has been compared with a new immunological test (Hemeselect) in patients referred for investigation of lower gastro-intestinal symptoms. Hemeselect was shown to have a higher sensitivity for colorectal carcinoma (94.0% compared with 58.0%), the greatest difference in sensitivity between the two tests being for rectal cancers. Similarly Hemeselect was more sensitive than Haemoccult for colorectal adenomas (66.6% vs 33.3%), and for inflammatory bowel disease (88.9% vs 33.3%). However the enhanced sensitivity of Hemeselect for colorectal neoplasia and inflammatory bowel disease was accompanied by a significant increase in the overall rate of positive reactions (32.8% of patients had a positive Hemeselect reaction compared with 14.8% who had a positive Haemoccult test), and a reduction in specificity (84.1% for Hemeselect vs 96.0% for Haemoccult). Hemeselect is a more sensitive indicator of colorectal neoplasia in symptomatic subjects, trials of its use as a screening test for asymptomatic neoplasia appear justified.

Adenoma↗
PubMed1992

The intraoperative localization of the obscure bleeding site using fluorescein.

Despite visceral angiography and radiolabeled gastrointestinal scintigraphy, the localization of gastrointestinal bleeding can still be a challenge. Even preoperative localization with visceral angiography is no guarantee of successful intraoperative localization or subsequent pathological confirmation. We report a case of obscure gastrointestinal bleeding of small bowel origin, which was localized intraoperatively by fluorescein injected via a superselectively placed catheter.

Angiography↗
PubMed1992

Psoriasis, psoriatic arthritis and the possible association with Sjögren's syndrome.

Thirty patients with psoriatic arthropathy (PA) were age- and sex-matched with patients with plaque psoriasis alone to investigate a possible link between Sjögren's syndrome (SS) and PA. The results of clinical examination, Schirmer's test, maximal stimulated salivary flow rate, haematological and serological investigations were compared in the two groups. Median maximal stimulated salivary flow rate was significantly reduced in patients with PA suggesting that salivary glands are affected in this condition. One patient with PA had SS.

Adult↗