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Biomedical subjects

M Cochran

Publications and source records attributed to M Cochran.

At least 19 recordsLinked to original sources

The effect of calcitriol on fasting urine calcium loss and renal tubular reabsorption of calcium in patients with mild renal failure--actions of a permissive hormone.

AIM: Renal production of 1,25-dihydroxycholecalciferol is attenuated in early renal failure. Renal tubular reabsorption of calcium is diminished in moderate renal failure and we wished to see if this were true in the early stages and whether supplementary calcitriol would bring about correction. We were interested in the idea of 1,25-dihydroxycholecalciferol being a permissive agent, operating indirectly. METHODS: We measured calcium-related variables, including calculated ultrafiltrable serum calcium, before and after calcitriol 0.5 microg daily for six days in 34 subjects with stable mild renal failure. RESULTS: The mean serum creatinine was 0.21 (+/- 0.08) mmol/l. The mean serum Ca++ was normal (1.18 mmol/l) but nine patients had values outside the normal range and in six cases, with low-normal serum Ca++ levels, there was a diminished tubular reabsorption. In five cases, basal serum Ca++ was mildly elevated. The coefficient of variation for serum Ca++ was 4.4%. PTH (1-84) levels were mildly elevated and 1,25-dihydroxycholecalciferol levels low-normal. The urine Ca/Cr, representing net bone resorption, was elevated in six cases. After calcitriol, the mean serum Ca++ level rose slightly and the coefficient of variation decreased to 3.6%. Changes in Ca++ whether upward or downward were accounted for by minor alterations in tubular reabsorption and a tendency to less net bone resorption. The initial Ca++ predicted (negatively) the magnitude of the correction. Neither the prevailing PTH nor the 1,25-dihydroxycholecalciferol levels explained any of the observed changes. CONCLUSION: In early renal failure, there may be impaired regulation of serum Ca++. Despite elevated PTH, mild hypocalcemia may exist in the presence of increased net bone resorption relative to GFR. Hypocalcemia was accounted for by reduced renal tubular reabsorption of calcium which corrected after calcitriol. Net bone resorption tended to fall after calcitriol. Mild hypercalcemia, when present, was corrected by a reduction in tubular reabsorption. Calcitriol did not have a simple unidirectional effect but instead contributed to efficiency of the homeostatic mechanisms controlling the serum Ca++ set-point.

Adolescent↗

Fetal heart rate decelerations during ECT-induced seizures: is it important?

Electroconvulsive therapy (ECT) is sometimes indicated during pregnancy and may offer advantages over pharmacotherapy for the patient and the fetus (1,2). However, very little data is available on the impact of epileptic or ECT-induced seizures on the fetus. We report a case of brief fetal heart rate decelerations in a fetus associated with maternal ECT-induced convulsions.

Adult↗

Limited effect of recombinant porcine interleukin-12 on porcine lymphocytes due to a low level of IL-12 beta2 receptor.

The cytokine interleukin-12 (IL-12) is a key molecule in the regulation of CD4 + T cell development and specifically potentiates T helper 1 responses in mouse and man. However, biological effects mediated by IL-12 have not been well defined in pigs. Herein, recombinant porcine IL-12 (rPoIL-12) was expressed in a swine poxvirus system as a biologically active heterodimer and used to stimulate bovine or swine lymphoblast cells. After 3 days of incubation, only bovine blasts were responsive to the rPoIL-12 treatment as monitored by cell proliferation in several independent trials. Similarly, i.m. administration of rPoIL-12 in the hind leg of 3-week-old pigs indicated a reduction in the number of interferon-gamma (IFN-gamma) producing lymphocytes isolated from inguinal lymph nodes. The porcine IL-12R beta2 (IL-12Rbeta2) sequence was cloned and results generated by reverse transcriptase polymerase chain reaction (RT-PCR) demonstrated that the expression of IL-12R on porcine blasts as measured by the relative levels of IL-12Rbeta2 mRNA was less than that in bovine blasts and are in agreement with the reduced proliferation response of swine blast cells to rPoIL-12 treatment. Real time PCR analysis demonstrated that after PBMC stimulation, bovine blasts had an 11-fold increase in IL-12Rbeta2 mRNA levels while porcine blasts had almost no change. These data support a mechanism for IL-12 stimulation in swine inconsistent with that observed in conventional models.

Amino Acid Sequence↗

Advances in cooled semen technologies: seminal plasma and semen extender.

This study evaluated motility and fertility of uncentrifuged and centrifuged equine semen following dilution in a skim milk-glucose extender with or without supplemental Tyrode's medium. In addition, the effect of seminal plasma addition to each extender was evaluated. For Experiment 1, motility of 48h cooled, stored spermatozoa was evaluated following eight dilution treatments: uncentrifuged and diluted 1:4 (v/v) in skim milk-glucose extender (EZ Mixin CSTJ; CST-1:4) or in CST supplemented 65:35 (v/v) with modified Tyrode's medium (KMT-1:4); uncentrifuged and diluted to 25x10(6) spermatozoa/ml in CST (CST-1:9) or in KMT (KMT-1:9); centrifuged and diluted in CST with 0% seminal plasma (CST-0) or 20% seminal plasma (CST-20) or centrifuged and diluted in KMT containing 0% seminal plasma (KMT-0) or in KMT containing 20% seminal plasma (KMT-20). Sperm motility parameters evaluated included percentage of total motile sperm (% TMOT), percentage of progressively motile sperm (% PMOT), curvilinear velocity (VCL) and straight-line velocity (VSL). Mean % PMOT was lower (P<0.05) for spermatozoa extended in CST-1:4 compared to CST-1:9, whereas, all motility parameters were reduced (P<0.05) in KMT-1:4 compared to KMT-1:9. Spermatozoa extended in CST-1:4 had greater % TMOT, % PMOT and VSL (P<0.05) than in KMT-1:4. Spermatozoa extended in CST-1:9 had greater (P<0.05) % PMOT than in KMT-1:9, however, VCL was greater (P<0.05) in KMT-1:9. Mean VCL and VSL were lower (P<0.05) for spermatozoa extended in CST-0 compared with CST-20, whereas, spermatozoa extended in KMT-0 had greater (P<0.05) % TMOT, % PMOT and VSL compared to spermatozoa extended in KMT-20. Mean % TMOT and % PMOT were greater (P<0.05) in CST-20 compared to KMT-20, however, KMT-0 increased (P<0.05) velocity measures (VCL and VSL) compared to CST-0. In Experiment 2, fertility of centrifuged spermatozoa diluted in either CST-20 or KMT-0 was similar (P>0.05). We conclude that modified Tyrode's medium was not detrimental to establishment of pregnancy. Use of modified Tyrode's medium may improve spermatozoal motility and pregnancy rates for cooled transport of semen from stallions in which all seminal plasma must be removed because of suspected toxic effects of seminal plasma on spermatozoal viability, however, Tyrode's medium may be detrimental to sperm motility when seminal plasma is present.

Animals↗

Effect of monthly intravenous cyclophosphamide in rapidly deteriorating multiple sclerosis patients resistant to conventional therapy.

Fourteen consecutive clinically definite relapsing-remitting multiple sclerosis (MS) patients were treated with monthly intravenous cyclophosphomide (CTX) for 6 months. All had experienced severe dinical deterioration during the 12 months prior to treatment with CTX despite treatment with conventional immunomodulating agents and intravenous methylprednisolone. Treatment with CTX led to improvement and neurologic stability within 6 months which was sustained for at least 18 months after the onset of treatment with CTX. Therapy with CTX was well tolerated. CTX may be of benefit in MS patients who experience rapid clinical worsening and are resistant to conventional therapy.

Adult↗

Embryo vaccination of turkeys against Newcastle disease infection with recombinant fowlpox virus constructs containing interferons as adjuvants.

Recombinant fowlpox viruses (rFPV) expressing the fusion and hemagglutinin-neuraminidase glycoproteins of Newcastle disease virus (NDV) as well as chicken type I interferon (IFN) or type II IFN were used to vaccinate specific pathogen-free (SPF) turkeys in ovo. No significant changes in the hatchability, survival rate, performance and weight gain were observed after vaccination with the rFPV vaccines in comparison to diluent-inoculated embryos. The rFPV-NDV-IFN-II construct induced the onset of anti-NDV antibody production in SPF birds at one week post hatch, one week earlier than other vaccine constructs. Three to five weeks post hatch, the turkeys were challenged with the neurotropic velogenic NDV strain Texas GB (NDV-GB-Tx). The rFPV-NDV-IFN-II construct was the most protective vaccine against NDV. rFPV vaccines significantly (p<0.05) suppressed the mitogenic response of peripheral blood leukocytes in vaccinated turkeys in comparison to placebo inoculated controls at 25 days post vaccination. Birds vaccinated with rFPV-NDV-IFN-I construct did not have an inhibition in the mitogenic response.

Animals↗

Immunogenicity and protective efficacy of a gE, gG and US2 gene-deleted bovine herpesvirus-1 (BHV-1) vaccine.

The efficacy and safety of a gene-deleted bovine herpesvirus-1 (BHV-1) vaccine was determined in a bovine herpesvirus challenge trial in calves. Three different doses of the vaccine were administered intramuscularly at 10(5), 10(6) and 10(7) PFU/ml and compared to a commercial vaccine and non vaccinated control calves. Challenge was performed by intranasal aerosolization with the Cooper strain of BHV-1 (3 x 10(4) PFU/ml). The non-vaccinated calves shed significantly (P < 0.05) more virus than all other groups on days 4, 8 and 10 post challenge. By day 14 post challenge, antibody titers for BHV-1 of calves vaccinated with 10(7) PFU/ml were significantly (P < 0.05) higher than the commercial or non-vaccinated calves. Clinical scores of non-vaccinated calves were significantly (P < 0.05) higher than all other groups on days 4-14 post challenge. With both radioimmunoprecipitation and competitive enzyme-linked immunosorbent assays (C-ELISA), calves in the gene-deleted vaccine groups mounted comparable specific responses against gB, gC and gD post vaccination as calves in the commercial vaccine group, but in a dose dependent manner. These data suggest that the gene-deleted BHV-1 vaccine tested may be used as an effective vaccine in controlling BHV-1 infections.

Administration, Intranasal↗

The real meaning of patient-nurse confidentiality.

Critical care nurses learn early in their careers that patient confidentiality is to be respected. Challenges to this belief come when public safety or justice seems to outweigh any individual's privacy. The resolution of the problem caused by such competing values may not be easy for a nurse and will necessarily demand examination of legal, ethical, and professional responsibilities.

Adult↗

Recombinant fowlpox viruses coexpressing chicken type I IFN and Newcastle disease virus HN and F genes: influence of IFN on protective efficacy and humoral responses of chickens following in ovo or post-hatch administration of recombinant viruses.

We have constructed recombinant (r) fowl pox viruses (FPVs) coexpressing chicken type I interferon (IFN) and/or hemagglutinin-neuraminidase (HN) and fusion (F) proteins of Newcastle disease virus (NDV). We administered rFPVs and FPV into embryonated chicken eggs at 17 days of embryonation or in chickens after hatch. Administration of FPV or rFPVs did not influence hatchability and survival of hatched chicks. In ovo or after hatch vaccination of chickens with the recombinant viruses resulted in protection against challenge with virulent FPV and NDV. Chickens vaccinated with FPV or FPV-NDV recombinant had significantly lower body weight 2 weeks following vaccination. This loss in body weight was not detected in chickens receiving FPV-IFN and FPV-NDV-IFN recombinants. Chickens vaccinated with FPV coexpressing IFN and NDV genes produced less antibodies against NDV in comparison with chickens vaccinated with FPV expressing NDV genes.

Animals↗

Home healthcare nursing in the managed care environment. Part II. The impact on clients and professional nurses.

Part I, published in last month's issue of Home Healthcare Nurse, provided information about managed care and health maintenance organizations (HMOs). This article, Part II, presents an overview of the history of home healthcare nursing, the results of a purposeful sample, and interviews of home care nurses. Interviews were conducted to determine how nurses perceived the impact of managed care on their clients and nursing practice. Conclusions are presented in terms of emergent categories gleaned from the interviews. Recommendations for the continued growth and advancement of professional nursing in the context of managed care are given.

Attitude of Health Personnel↗

Home healthcare nursing in the managed care environment. Part I. Managed care: and overview.

Dramatic changes in the provision of healthcare from fee-for-service to managed care have had a definitive impact on consumers as well as providers. As providers and recipients of healthcare, home care nurses must be knowledgeable about managed care and Health Maintenance Organizations (HMOs): This article, part 1 of a two-part series, discusses the tenets of managed care and the different types of HMOs. Part 2, in next month's issue, discusses the historic background of home care and home care nurses perceptions of the impact that managed care has on clients and the practice of home care nursing.

Community Health Nursing↗

Production of chicken chimeras from injection of frozen-thawed blastodermal cells.

To execute a strategy for reconstituting genetic resources from cryopreserved blastodermal cells, experiments were conducted to optimize conditions for producing chimeric chickens from frozen-thawed blastodermal cells. Stage X blastodermal cells were collected from Barred Plymouth Rock embryos and dispersed. Cells were resuspended in 10% dimethyl sulfoxide in Dulbecco's modified Eagle's medium (DMEM) containing 20% fetal bovine serum, and distributed into plastic ampules. Cell suspensions were seeded to induce ice formation at -7 C, cooled from -7 to -35 C at 1 C/min and then ampules were plunged into liquid nitrogen. Thawing was done by plunging the ampules into warm water (37 C) for 3 min. After centrifugation, the supernatant was replaced with DMEM, and dead or broken cells were removed by density gradient centrifugation. Approximately 500 cells were injected into irradiated Stage X White Leghorn recipient embryos. Following incubation, several somatic chimeras were produced. The frequency of somatic chimerism when fresh (unfrozen) cells, or cells that were frozen and selected by density gradient centrifugation on Percoll or Nycoprep were injected into recipient embryos was 84, 79, and 85%, respectively. The percentage of donor-derived pigmentation in the down of these chimeric chickens was 79, 50, and 58%, respectively. Germline chimerism was determined by mating the chimeras that survived to sexual maturity to Barred Plymouth Rocks. Nine of 16 birds (56.2%) injected with fresh cells, 2 of 26 birds (7.7%) injected with cells that were frozen and selected by density gradient centrifugation on a Percoll gradient, and 3 of 26 birds (11.5%) injected with cells that were frozen and selected on a Nycoprep gradient showed germline transmission; the percentage of donor-derived progeny in these chimeras were 29.5, 5.2, and 6.8%, respectively. The Barred Plymouth Rock donor stock was "reconstituted" by inter se mating of germline male and female chimeras. These data demonstrate that the strategy described here for reconstituting genetic resources from cryopreserved blastodermal cells via chimeric intermediates can be performed successfully.

Animals↗

A genomic map of infectious laryngotracheitis virus and the sequence and organization of genes present in the unique short and flanking regions.

We present a genomic map of infectious laryngotracheitis virus (ILT) and an 18,912 bp sequence containing the entire unique short region and a portion of the flanking short repeats. In determining the genomic map, an 856 bp region repeated as many as 13 times was identified within the short repeats. The unique short sequence contains nine potential open reading frames (ORFs). Six of these ORFs show homology to other known herpesvirus unique short genes. Using the herpes simplex virus nomenclature, these genes are the US2, protein kinase, and glycoproteins G, D, I, and E (ORF 1, 2, 4, 6, 7, and 8, respectively). Interestingly, an open reading frame with homology to HSV-1 UL47 (ORF 3) is found in the unique short. One very large open reading frame (ORF 5) is present and contains a threonine-rich, degenerate repeat sequence. This gene appears to be unique to ILT among sequenced herpesviruses. Two ORFs were identified within the short repeat (SR) region. SRORF 1 is homologous to a gene (SORF3) found in the unique short region in both MDV and HVT, and appears to be specific to avian herpesviruses. SRORF 2 has homology to HSV US10.

Amino Acid Sequence↗