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Biomedical subjects

J Webb

Publications and source records attributed to J Webb.

At least 217 records · Page 12Linked to original sources

Iron levels and major iron binding proteins in the plasma of ammocoetes and adults of the southern hemisphere lamprey Geotria australis Gray.

1. The major plasma iron binding proteins (IBP) of both larval and adult Geotria australis differ from those of other vertebrates. 2. Larval IBP has a M.W. of approximately 354,000 and is composed of 20 subunits of equal M.W. 3. Adult IBP is a tetramer (M.W. = c. 296,000) which readily dissociates into subunits of approximately 78,000. 4. Confirmation that plasma iron binding proteins were similar to ferritin in larvae and transferrin in adults was provided by pI values, Fe/protein ratios and electron microscopy. 5. Total plasma iron was 19,760 micrograms/100 ml in larvae and 34 micrograms/100 ml in adults.

Animals↗

Mössbauer spectroscopic studies of hemerythrin from Phascolosoma lurco (syn. Phascolosoma arcuatum).

Hemerythrin from coelomic cells of Phascolosoma lurco (syn. P. arcuatum) was isolated by gel filtration as two components, hemerythrin-I (25%) and hemerythrin-II (75%). The Mössbauer spectrum of oxyhemerythrin-II consisted of two pairs of lines of the same isomer shift (0.5 mm s(-1) corresponding to Fe(III) but different quadrupole splitting (1.01 and 2.02 mm s(-1). Application of a 2.5-T magnetic field at 4.2 K caused no significant spectral broadening. The 2FE.O2 binding site thus contains two nonequivalent high-spin Fe(III) ions that are antiferromagnetically coupled. The Mössbauer spectra of the minor component, hemerythrin-I, indicated an identical binding site. On deoxygenation, the spectrum was dominated by a simple quadrupole split doublet corresponding to Fe(II), indicating that the binding site in this derivative contains two identical Fe(II) ions that interact only weakly, if at all. The Mössbauer spectra of azidohemerythrin-II indicated that this derivative also contains a pair of antiferromagnetically coupled Fe(III) ions with the same isomer shift (0.5 mm s(-1)) but quadrupole splittings (1.40 and 1.96 mm s(-1)) that are not identical with those in oxyhemerythrin.

Animals↗

Pregnancies in humans by fertilization in vitro and embryo transfer in the controlled ovulatory cycle.

Normal pregnancies have been established in four women with tubal infertility by fertilization in vitro, embryo culture, and embryo transfer after stimulation of follicular growth with clomiphene citrate. In three of these women the time of oocyte maturation was controlled by human chorionic gonadotropin. This procedure for the control of ovulatory response has many advantages when compared with the previously successful method of using the natural ovulatory cycle.

Chorionic Gonadotropin↗

A clinical assessment of nine pregnancies obtained by in vitro fertilization and embryo transfer.

An analysis of nine pregnancies resulting from in vitro fertilization and embryo transfer was made in order to identify factors common to all of the pregnancies. These factors included clomiphene stimulation; general anesthesia for laparoscopy; identification of large follicles (greater than 8 ml) and a mature oocyte; preincubation of the oocyte for 4.7 to 6.5 hours in vitro before insemination; insemination with 0.8 to 1.3 x 10(6) fresh spermatozoa from fertile samples; transfer to the uterus of two-, four-, and eight-cell embryos, 38 to 50 hours after insemination; and uncomplicated uterine transfers of embryos. It was difficult to determine whether these factors are causal or coincidental in the attainment of successful pregnancies. The detailed analysis was useful in demonstrating factors which did not prevent the establishment of pregnancy by in vitro fertilization and embryo transfer. These factors included a variety of causes of infertility, including idiopathic and male infertility; age of the infertile woman over 35 years; the presence of T-mycoplasma in the genital tract; the use of human chorionic gonadotropin; a variety of agents used for general anesthesia; the use of carbon dioxide to induce pneumoperitoneum; a delay of up to 50 minutes in the interval between the induction of general anesthesia and oocyte recovery; the use of antiprostaglandins at the time of embryo transfer; and a brown discharge from the vagina following embryo transfer.

Embryo Transfer↗

Treatment of xerostomia: a double-blind trial in 108 patients with Sjögren's syndrome.

The first-ever controlled study of a therapeutic modality for xerostomia is reported. A recently described formulation for saliva substitute (SS) has been tested against a glycerine mouthwash as a control saliva substitute (placebo) in a double-blind clinical trial in 108 patients with varying grades of xerostomia of Sjögren's syndrome. The results indicate that SS offered significant relief of nocturnal oral discomfort (p less than 0.02) and more patients reported "excellent" improvement (p less than 0.01) on a five-point graded response. In all other respects, the SS was not significantly better than the placebo. Significant adverse effects were not reported. It is suggested that any such current and future therapeutic modalities for Sjögren's syndrome be subjected to similar critical appraisal of their worth.

Clinical Trials as Topic↗

Fibre type changes in striated muscle of alcoholics.

Striated muscle from patients taking more than 80 g of alcohol each day shows selective atrophy of the type II fibres which are dependent on glycogenolytic pathways. This atrophy is associated with an excess of glycogen and lipid within the fibres and may represent a selective metabolic insult.

Adult↗

Time course of response to prednisolone in chronic airflow obstruction.

Nineteen patients with chronic airflow obstruction measured their morning and evening peak expiratory flow (PEF) daily for 28 days. A placebo was taken for the first week and prednisolone 20 mg twice daily was taken for the last three weeks. The mean PEF in 13 patients who responded to prednisolone reached a maximum after eight days' treatment. The majority of the 19 patients had asthma and were thought to represent a typical cross section of patients who would be considered for a trial of oral corticosteroids. Most responsive patients will achieve a maximum response within eight days.

Adult↗

Recovery of plasma corticotrophin and cortisol levels after three-week course of prednisolone.

Patients with chronic airflow obstruction were given a three-week course of prednisolone 40 mg per day. The basal plasma cortisol level and response to tetracosactrin were depressed after such a course. Basal plasma cortisol and corticotrophin (ACTH) levels were measured on five consecutive days after three weeks of treatment with prednisolone and were found to rise simultaneously to control levels within three days. Pituitary and adrenal functions were depressed for four days after short high dose courses of corticosteroids and patients may be at risk if they encounter stress during this time.

Adrenal Cortex Function Tests↗

The investigation of idiopathic infertility by in vitro fertilization.

The results of in vitro fertilization of mature oocytes obtained at diagnostic laparoscopy from patients with both known and unknown clinical causes of infertility are presented. A simple regimen involving the use of clomiphene and human chorionic gonadotropin which enabled laparoscopy to coincide with available surgical lists resulted in the recovery of mature oocytes from 15 of the 18 patients treated. Apparently normal embryos developed from five of six oocytes recovered from patients who had blocked fallopian tubes or who were being investigated after 8 to 12 months of artificial insemination by donor. No normal embryos developed from oocytes from nine patients who had sustained infertility of unknown cause for 2 years or more. When this latter group was compared with other groups a high rate of fertilization failure was noted, and severe polyspermy developed in two cases. The results are discussed in relation to the diagnosis of infertility and the management of infertile patients.

Embryo, Mammalian↗

Computerised clinical data base system--Australia.

In search for a practical solution to analyse a large quantity of medical information, rheumatic disease data base system (RDDS) is described. Details of data configuration, data entry and retrieval are discussed in some detail. The system incorporates a range of commonly used statistical tests and provisions for more advanced data analysis are made. Additional facilities include provisions for a variety of printed reports, back up facilities and a word processor. The ease of system operation and flexibility are emphasised. Technical support requirements are minimal even when new applications are being developed. The system is fully operational at present and can be implemented on a number of computer systems.

Australia↗

A technique for the treatment of large irregular fields.

Each method of producing irregular shaped fields has its own particular advantage. This report describes one technique of irregular field production with minimal handling of the shielding material, tapered shielding to provide the greatest accuracy in the field shape, and rapid achievement of patient setup. The reproducibility of these fields is considered.

Humans↗

A comparison of biopsy results using rigid and fibreoptic bronchoscopes.

A comparison of the results of bronchial biopsy in the histological diagnosis of lung cancer obtained via the fibreoptic bronchoscope and the rigid bronchoscope has been made. Positive biopsy rates of 72% with the fibreoptic bronchoscope and 51% with the rigid bronchoscope were obtained (P less than 0.001). Evidence is presented to show that this difference was not due to selection of patients. The negative biopsy rates in the presence of proven visible tumour were 9% with the fibreoptic bronchoscope and 16% with the rigid bronchoscope.

Bronchi↗

In vivo anti-nuclear antibodies in epithelial biopsies in SLE and other connective tissue diseases.

In vivo anti-nuclear antibody (ANA) was observed by direct immunofluorescence microscopy in epithelial cell nuclei in forty-four biopsies from thirty-three patients. The tissue containing the ANA was macroscopically normal in twenty-seven patients. The thirty-three patients with in vivo biopsy ANA included twenty-three with SLE, three with mixed connective tissue disease, two each with multi-system Sjögren's syndrome, dermatomyositis, and progressive systemic sclerosis, and one with rheumatoid arthritis. Features of sicca syndrome were noted in seventeen patients. The patterns of the in vivo biopsy ANA in the thirty-three patients were speckled (21), homogeneous (6), nodular (2), and both speckled and homogeneous (4). Complement was not detected in the epithelial cell nuclei. Immunoglobulin(s) and/or complement were deposited along the dermoepidermal junction in thirty-two of the forty-four biopsies, and in dermal blood vessels in twenty-two biopsies. Each patient had serum ANA against rat liver substrate; twenty-seven had high titre ANA (1 in 1000 or greater). Elevated levels of DNA-binding were found in twenty patients (61%), but the level of DNA-binding did not correlate with the intensity of in vitro biopsy ANA staining. Serum antibody to ribonucleoprotein (RNP) was present in eight of the twenty-three patients tested (35%), all eight patients having clinical features of sicca syndrome. Hypocomplementaemia was found in thirteen patients (40%), all of whom had active SLE. In vivo biopsy ANA appears to be a real phenomenon of unknown aetiology, and not an artifact, which is found in some patients with active multisystem autoimmune disease, especially SLE.

Adult↗

Plasmacytoma of the stomach: diagnosis with the aid of immunoperoxidase technique.

A gastric tumor, originally diagnosed as a plamacytoma in 1953, but in which the diagnosis was disputed, has been re-examined by the immunoperoxidase staining technique. The demonstration of a single type of immunoglobulin in the tumor cells is considered conclusive evidence of its neoplastic nature. Two further cases of gastrict plasmacytoma encountered in recent months have also been examined by this technique and similar results obtained. The pathology of plasma cell tumors is discussed and a brief review of the literature is added with regard to the management and the overall poor prognosis.

Clone Cells↗

Severe hypercapnia associated with a non-respiratory alkalosis.

A case of hypoventilation in response to a non-respiratory alkalosis is presented. It is postulated that the degree of hypoventilation encountered was a normal response and that a fall in intracellular hydrogen ion concentration was responsible for the hypoventilation. This explains why the alkalosis associated with potassium deficiency is not associated with hypoventilation since the intracellular hydrogen ion concentration then remains constant. The renal response in this condition is responsible for maintaining the alkalosis and seems to be aimed at sodium conservation and hence plasma volume control rather than defence of acid-base balance.

Alkalosis↗

Clinico-laboratory aspects of anti-nuclear and anti-native DNA antibody tests.

Available techniques for detection of anti-nuclear antibodies are here briefly reviewed. The relatively insensitive LE cell test has been largely supplanted by the indirect immunofluorescent ANA test which should be reported in terms of titre and pattern. Specific measurement of nDNA antibodies is now a regular technique in SLE diagnosis and management.

Antibodies, Antinuclear↗