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Biomedical subjects

J M Cummins

Publications and source records attributed to J M Cummins.

At least 19 recordsLinked to original sources
PubMed1999

Fate of genetically marked mitochondrial DNA from spermatocytes microinjected into mouse zygotes.

Cytoplasts from single spermatocytes of NZB/BinJ mice were separated from the nuclei and individually microinjected into B6D2F1 (C57BL/6 x DNBA/2J) hybrid embryos at the pronuclear stage (20 h after hCG injection). Of 363 zygotes injected, 311 (86%) survived and developed. From these experiments, we transferred 222 embryos into 20 pseudopregnant recipients. Eighteen (90%) became pregnant and 82 pups were born (37% of transfers). Mitochondrial DNA (mt DNA) from the NZB/BinJ strain lacks a RsaI restriction site and can thus be distinguished from the host embryo following PCR amplification. We were unable to detect the transferred mtDNA in blastocysts on day 4-5 after injection. Nor could we detect NZB/BinJ mtDNA in placentae, nor in tissues from mice born to host mothers following the transfer of blastocysts that developed from injected zygotes. Rejection of paternal mitochondria by the embryo normally occurs at the 4- to 8-cell stage in mice and is apparently dependent on mutual recognition between the mitochondria and the nuclear genome. We conclude that this mechanism has probably already developed by the time the germ cells have become committed to meiosis.

Animals↗
PubMed1999

Oral use of interferon.

Interferon-alpha (IFN-alpha) given orally has biological activity in humans and other animals. The dose providing the most benefit delivers IFN-alpha to the oral mucosa in a concentration (10(2)-10(3) IU), similar to that naturally produced in the nasal secretions during respiratory infections. In contrast, conventional IFN therapy employs parenteral doses of > 10(6) IU and, for this reason, orally administered IFN therapies have been called low-dose treatments. Efficacy in both animal disease models and human studies has been reported, and the mechanisms whereby oral administration has a systemic effect are under active study in a number of laboratories.

Administration, Oral↗
PubMed1999

Natural human interferon-alpha administered orally as a treatment of bovine respiratory disease complex.

Natural human interferon-alpha (nHuIFN-alpha) from three sources was given orally to 368 calves experiencing a natural outbreak of bovine respiratory disease complex (BRDC). In one study, 200 calves were given one treatment daily for 3 days of placebo or 20, 200, or 2,000 IU of nHuIFN-alpha before shipment. Calves treated with 20 or 200 IU had a significant (p < 0.05) weight gain benefit for the first 21 days in the feedlot, if they had rectal temperatures <40 degrees C when treated with nHuIFN-alpha. In a second trial, 168 mixed-breed calves (five groups randomized to 31-36 calves/group) were treated with one dose of placebo or 200 or 400 IU of nHuIFN-alpha after shipment to the feedlot. Using this regimen, a dose of 200 IU per calf significantly (p < 0.08) decreased the number of sick calves per group and delayed development of BRDC. Results of these studies demonstrate that oral administration of nHuIFN-alpha, which may partially mimic the nasally secreted IFN response reported during BRDC, may be beneficial in cattle.

Administration, Oral↗
PubMed1999

Single-step method for the determination of the amount of the common deletion in mitochondrial DNA.

A fluorescent-based quantitative PCR assay to measure the percentage of the common deletion in rat mitochondria is reported. The amount of the common deletion is measured relative to the amount of total mitochondrial (mt)DNA. The use of a heterologous competitor construct allows the reaction to be monitored to ensure that exponential accumulation of products occurs. The use of fluorescence-labeled primers provides a safe and sensitive means to quantify products without any adjustment for size. This assay will allow the quantitative determination of the common deletion with one dilution range.

Animals↗
PubMed1998

Fate of microinjected spermatid mitochondria in the mouse oocyte and embryo.

Mouse round spermatids labelled with MitoTracker were microinjected into Sr(2+)-activated mouse oocytes. The labelled mitochondria were tracked up to the morula/blastocyst stage using fluorescence microscopy. The overall incidence of embryos with labelled mitochondria fell from 80% in the 1-cell zygote to 25% in 2-cell, 9% in 4-cell and approximately 1% in 8-cell or later stages. Thus it appears that almost all round spermatid mitochondria finally disappear from embryos during the 4-cell to 8-cell transition, as happens for mature spermatozoa (Cummins et al. Zygote 1997, 5:301-8). The spermatid mitochondria remained tightly bound together during this process. In contrast, labelled primary spermatocyte and cumulus mitochondria dispersed rapidly throughout the oocyte cytoplasm within 3 h. We hypothesise that spermatid mitochondria may be bound together by cytoskeletal elements produced in the early haploid spermatid. These elements, together with terminal differentiation of the sperm mitochondria, may be central to the processes by which the embryo 'recognises' the sperm mitochondria and inhibits inheritance of paternal mitochondrial DNA. These results suggest that round spermatid injection for infertile men will not pose a significant risk to offspring by transmitting abnormal mitochondrial genomes.

Animals↗
PubMed1998

Low dose oral interferon alpha 2a in HIV-1 seropositive patients: a double-blind, placebo-controlled trial.

Low dose oral interferon alpha has been shown to be of benefit in viral disease in animals. In a double-blind, placebo-controlled trial, 177 patients seropositive for HIV-1 were randomly assigned to receive placebo or recombinant human interferon alpha 2a (rIFN alpha). Endpoints were survival, alteration of disease classification, performance, and changes in CD4+ T cell numbers. There was a trend for improved survival in the group receiving rIFN alpha at the dose of 1.0 IU/lb. The changes in disease classification or in weight were not significantly different. Performance was improved to a greater extent (p=0.1) in the patients who received the two higher rIFN alpha dosages (1.0 IU/lb and 10.0 IU/lb) at 6 months. In addition, the CD4+ T cell count was improved only in the 1.0 IU/lb dose treatment group at 6 months. Treatment with low dose oral interferon at 1.0 IU/lb was associated with improved CD4+ T cell count, performance and a trend toward enhanced survival in HIV seropositive patients. These differences were, however, not statistically significant. A larger study, with better return rate, will be needed to determine whether low dose, oral interferon alpha is actually beneficial for these patients.

Animals↗
PubMed1998

Semen levels of mitochondrial DNA deletions in men attending an infertility clinic do not correlate with phenotype.

In view of previous reports associating mitochondrial DNA deletions with male reproductive disorders, levels of the 'common' 4977 bp mitochondrial DNA deletion were evaluated semi-quantitatively in 64 men, without prior knowledge of the clinical diagnosis. Significant levels of deletions were detected in 34/64 men (53%) but 29 of these (45%) had a normal semen profile and were phenotypically normal. No deletions were detected in 30 men, of whom 21 were normospermic, six were oligozoospermic and three were azoospermic. It is concluded that although mitochondrial DNA deletions within the testis may be associated with primary testicular disease, no correlation with semen quality was evident in this study, thus limiting its potential use as a diagnostic test.

DNA, Mitochondrial↗
PubMed1997

Fate of microinjected sperm components in the mouse oocyte and embryo.

Intact mouse sperm or mouse sperm tails alone, labelled with MitoTracker Green FM fluorochrome, were injected into mouse oocytes and the cells cultured in vitro for up to 5 days. The dye stained midpiece mitochondria, the sperm tail coarse fibres and the sperm perforatorium. Intact sperm (or tails injected with separated heads) induced normal embryonic development. The mitochondria could be identified in embryos up to the 4-cell stage, remaining associated with the sperm tail. They largely disappeared by the 8-cell stage, when only a minority of embryos (6/43) could be found with small patches of mitochondria. Axonemal elements could be identified coiled up in single external blastomeres as late as day 5 blastocysts. By contrast, mitochondria as well as tail components could be identified up to 5 days after injection of sperm tails alone into non-activated oocytes and also in embryos that arrested development before the 8-cell stage. We conclude that disappearance of the labelled sperm mitochondria in normally cleaving embryos is not due to fading or inactivation of the fluorochrome marker, but is rather an event specifically tied to cell cycle activities around the second cell division.

Animals↗
PubMed1997

Inflammatory markers in bronchoalveolar lavage fluid of standardbred racehorses with inflammatory airway disease: response to interferon-alpha.

Protein and eicosanoid concentrations and procoagulant activity were determined in bronchoalveolar lavage fluid (BALF) from 32 Standardbred racehorses with inflammatory airway disease (IAD) and 6 control horses. Total protein, albumin and immunoglobulin G (IgG) concentrations were high (P < 0.05) in the BALF from horses with IAD, a finding consistent with exudation of plasma protein into the airway. Immunoglobulin A (IgA) concentrations also were increased (P < 0.05) which may signify local immunoglobulin production. Difference was not detected in prostaglandin E2 and 6-ketoprostaglandin F1 alpha concentrations in BALF of IAD-affected and control horses. Procoagulant activity was identified in the majority (66%) of BALF samples from IAD-affected horses and was not detected in control horses. Natural human interferon-alpha (nHulFN alpha) (placebo, 50, 150, or 450 units) was administered orally for 5 days to IAD-affected horses in a double-blind, randomised block design. Total protein, IgG, and IgA concentrations in BALF were reduced (P < 0.05) 8 days after administration of 50 u and 150 u nHuIFN alpha, and 15 days after administration of 50 u nHuIFN alpha. Procoagulant activity and albumin concentrations in BALF were lower 8 days after administration of 50 u nHuIFN alpha. Oral administration of low-dose nHuIFN alpha appeared to ameliorate these parameters of lower respiratory tract inflammation in Standardbred racehorses with IAD.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Misconceptions about mitochondria and mammalian fertilization: implications for theories on human evolution.

In vertebrates, inheritance of mitochondria is thought to be predominantly maternal, and mitochondrial DNA analysis has become a standard taxonomic tool. In accordance with the prevailing view of strict maternal inheritance, many sources assert that during fertilization, the sperm tail, with its mitochondria, gets excluded from the embryo. This is incorrect. In the majority of mammals-including humans-the midpiece mitochondria can be identified in the embryo even though their ultimate fate is unknown. The "missing mitochondria" story seems to have survived--and proliferated-unchallenged in a time of contention between hypotheses of human origins, because it supports the "African Eve" model of recent radiation of Homo sapiens out of Africa. We will discuss the infiltration of this mistake into concepts of mitochondrial inheritance and human evolution.

Animals↗
PubMed1996

Changes in airway inflammatory cell populations in standardbred racehorses after interferon-alpha administration.

Natural human interferon-alpha (nHuIFN alpha) was administered to actively training Standardbred racehorses with inflammatory airway disease (IAD). Inflammatory airway disease was characterized by poor exercise performance and inflammation and exudate in the upper and lower airway. Placebo, 50, 150, or 450 units(U) of nHuIFN alpha was administered orally for 5 consecutive days to eight horses per treatment group in a double-blind, randomized block design. Response to nHuIFN alpha was monitored by semiquantitative endoscopic examination score and cytologic examination of bronchoalveolar lavage fluid (BALF) performed at baseline (Day 1), Day 8 and Day 15 after initiation of nHuIFN alpha administration. Neutrophil, macrophage, lymphocyte, and nucleated cell counts in BALF were lower (P < 0.05), compared with BALF cell counts in placebo-treated horses 8 days after administration of 50 U and 150 U nHuIFN alpha, and 15 days after administration of 50 U nHuIFN alpha. Neutrophil, lymphocyte and nucleated cell counts were lower than cell counts from placebo-treated horses, 8 days following administration of 450 U nHuIFN alpha. The proportion CD4-, CD5-, and CD8-positive lymphocytes in BALF was not affected by administration of nHuIFN alpha. Oral administration of low-dose nHuIFN alpha reduced inflammation of the lowest respiratory tract in Standardbred racehorses with IAD.

Administration, Oral↗
PubMed1996

Comparison of the long-term effects of treatment with oral and parenteral interferon alpha in chronic viral hepatitis patients.

This report presents the interferon alpha (IFN-alpha) treatment results for 75 patients with chronic hepatitis B virus (HBV) (51 cases) and hepatitis C virus (HCV) (24 cases) induced hepatitis in maximal 61 months follow-up. Among the group of 51 patients with chronic HBV hepatitis, 35 were treated orally with IFN-alpha in the form of lozenges in low daily doses (37.5-150 U). The treatment was completed in 32 cases. The remaining 16 patients with chronic HBV hepatitis completed the treatment with parenteral IFN-alpha (3 x 10(6) U, 3 times a week). Positive results measured by the use of seroconversion in the HBe-antigen system were obtained for 68.7% (5-61 months follow-up) and 56.2% (7-44 months follow-up) of the patients treated with oral and parenteral IFN-alpha, respectively. Among the group of 24 patients with chronic HCV hepatitis, the first 6 patients were initially treated with IFN-alpha in the form of lozenges, in low daily doses. Biochemical remission was not achieved in these patients; genotype 1b was documented in 4 of them. Both, the first 6 patients (after a break) and the remaining 18 were treated with IFN-alpha parenterally, as in HBV patients. Temporary clinical and biochemical remission was achieved in 62.5% of the cases during the treatment, however the durable remission observed during 6-29 months of follow-up was achieved in 20.4 of the cases only.

Administration, Oral↗
PubMed1995

Oral treatment of transmissible gastroenteritis with natural human interferon alpha: a field study.

During a natural outbreak of transmissible gastroenteritis (TGE), groups of piglets were treated orally for 4 consecutive days with placebo or 1.0, 10.0 or 20.0 international units (IU) natural human interferon alpha (nHuIFN alpha). Piglets that were 1-12 days of age and given 1.0, 10.0 or 20.0 IU nHuIFN alpha had significantly (P < 0.01) greater survival rates than placebo-treated piglets; survival rates were the greater for the highest level of nHuIFN alpha treatment. In contrast, beneficial effects of nHuIFN alpha were not observed in piglets farrowed during the disease outbreak and given nHuIFN alpha within hours of birth. Oral nHuIFN alpha therapy modulates the natural course of high morbidity and mortality commonly seen with TGE.

Administration, Oral↗
PubMed1995

Cytologic evaluation of bronchoalveolar lavage fluid obtained from standardbred racehorses with inflammatory airway disease.

Cytologic examination of bronchoalveolar lavage fluid (BALF), including phenotypic analysis of lymphocytes, was performed on 32 Standardbreds with poor race performance and endoscopic examination findings characteristic of inflammatory airway disease (IAD). Nucleated cell counts in BALF from IAD-affected horses were higher than those in control horses; the cytologic profile of BALF in affected horses included mixed inflammation, characterized by mild neutrophilia, lymphocytosis, and monocytosis. Eosinophil and mast cell counts were not higher in the IAD-affected group, compared with those in the control group; however, 4 IAD-affected horses had marked eosinophilia (24.7 +/- 4.8% SEM) in BALF. Phenotypic analysis of lymphocytes in BALF obtained from IAD-affected horses revealed a low proportion of CD4-positive cells and B cells, compared with those in the control group; these findings may have been representative of a greater proportion of non-B, non-T cells (null cells) in horses with IAD. The cytologic profile of BALF obtained from horses with IAD differed from that in horses affected with chronic obstructive pulmonary disease, suggesting that the pathogenesis of inflammation in horses with IAD may differ from that of chronic obstructive pulmonary disease.

Animals↗