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Biomedical subjects

J L Burton

Publications and source records attributed to J L Burton.

At least 19 recordsLinked to original sources
PubMed1992

Hematological profiles in dairy cows treated with recombinant bovine somatotropin.

Recombinant bovine somatotropin (bST) was administered at 0, 10.3, or 20.6 mg per cow per day to 32 Holsteins for 38 wk. Fifteen currently treated cows had been treated in the previous lactation. Eighteen hematological variables and blood concentration of insulin-like growth factor I (IGF-I) were measured at five sample periods. The objectives of the study were to test the effects of bST treatments on hematological profiles and to relate blood IGF-I concentration to these variables. Results indicated little influence (P greater than .10) of previous bST treatments on hematological profiles measured in the current lactation. Current bST treatments, however, altered hematocrits (P = .10), mean corpuscular volume (P = .03), mean corpuscular hemoglobin (P = .009), and fraction of blood lymphocytes (P = .09). A week x bST treatment interaction also contributed to variation in hematocrit (P = .09), mean corpuscular hemoglobin (P = .05), fraction of neutrophils (P = .02), and fraction of lymphocytes (P = .04). Blood IGF-I concentration influenced fractions and counts of neutrophils (P = .06, .09), lymphocytes (P = .04, .02), and monocytes (P = .08, .05). Further in vivo and in vitro studies are warranted because this preliminary evidence suggests that bST and(or) IGF-I contribute to regulation of hematopoiesis in mature dairy cows.

Analysis of Variance↗
PubMed1992

Contact sensitivity and systemic antibody responses in dairy cows treated with recombinant bovine somatotropin.

Effects of exogenous bST on humoral and cell-mediated immune responses in lactating dairy cows were determined. The systemic antibody response to human erythrocytes and the cutaneous sensitivity response induced by dinitrochlorobenzene were the immune responses investigated. Cows were treated with either 0, 10.3, or 20.6 mg of bST/d for 266 d starting between wk 4 and 5 of lactation. Systemic immunizations and contact sensitivity were initiated during midlactation, 22 wk after bST treatments began. Hemagglutinating antibody titers and areas under the response profiles were not statistically different for bST-treated versus control cows. The cutaneous sensitivity response was similarly not affected by bST administration. Present antibody titer results agreed with our previous observations that bST did not affect serum IgM concentrations, but the cutaneous sensitivity results were in contrast with our finding of augmented proliferative responsiveness of mitogen-stimulated peripheral blood lymphocytes in bST-treated versus control cows. It is possible that exogenous bST affects some immune processes and lymphocyte subsets and not others. Further research is required to determine the practical significance of the variable immunomodulation elicited by exogenous bST.

Analysis of Variance↗
PubMed1991

Tissue kallikrein and kininogen in human sweat glands and psoriatic skin.

The cellular localization of immunoreactive tissue kallikrein and kininogen was studied in normal and psoriatic human skin. Immunoreactivity to both enzyme and substrate was observed in secretory granules of the dark cells in the secretory fundus (acinus) of the sweat glands. Double immunostaining revealed a segmental distribution of the two antigens. Each acinar section contained either tissue kallikrein or kininogen. However, there appeared to be a junctional zone in which both were present, but in separate dark cells. Immunoreactivity for both antigens was also observed in close apposition to the luminal microvilli of the duct cells. No specific immunostaining was seen in sebaceous glands, hair follicles, keratinocytes and other cells of the secretory unit such as myoepithelial or clear cells. In psoriatic skin there were in addition many neutrophils immunoreactive for tissue kallikrein in the epidermis and psoriatic scales. Mitogenic action of kinins may account to some extent for the characteristic accelerated turnover of epidermal cells in psoriasis and locally applied kinin antagonists may prove of value in the treatment of this disease.

Humans↗
PubMed1991

Influence of exogenous bovine somatotropin on the responsiveness of peripheral blood lymphocytes to mitogen.

Our objectives were to determine the effects of exogenous bovine somatotropin on peripheral blood lymphocyte responsiveness to mitogen and on concentrations of serum insulin-like growth factor-I and to determine whether a statistical relationship exists between these two variables. The cows on trial were treated with 0, 10.3, or 20.6 mg/d somatotropin, starting between wk 4 and 5 of lactation and continuing for 266 consecutive d. Lymphocyte proliferation (counts per minute) and concentration of insulin-like growth factor-I (nanograms per milliliter) were recorded from blood sampled at wk 3, 10, 26, 35, and 46 of lactation. The results showed that lymphocytes from the blood of treated cows responded to mitogen with higher proliferative responsiveness than cells from control cows, but that this effect required long-term treatment and adequate mitogen concentrations to be detected. The blood of treated cows also had elevated concentrations of insulin-like growth factor-I relative to that of control cows, but these were not statistically associated with the proliferative responsiveness of the peripheral blood lymphocytes to mitogen. Our results suggest that somatotropin has a role in the immune system of cows, but its mode of action and target tissues must be determined. Bovine somatotropin, injected at doses that increase milk yield, can augment cow immunity as judged by the proliferative responsiveness of peripheral blood lymphocytes in culture.

Analysis of Variance↗
PubMed1991

Serum immunoglobulin profiles of dairy cows chronically treated with recombinant bovine somatotropin.

The objective of this study was to determine the effects of exogenous somatotropin on blood profiles of the major bovine Ig isotypes. Holsteins were treated with either 0, 10.3, or 20.6 mg recombinant bST/d. Subcutaneous injections were started between wk 4 and 5 of lactation and continued for 266 d. Blood samples were collected by coccygeal venipuncture throughout lactation for serum IgG, G1, G2, A, and M concentration determination. Cows treated with 10.3 mg of bST/d exhibited modest increases in mean blood concentrations of IgG (12.4%) and IgG2 (18.4%) relative to the other groups of cows. In addition, treated cows had 10.1% higher average concentration of IgA than controls. Somatotropin did not influence average lactational concentrations of IgG1 or IgM, although the group receiving 10.3 mg/d had higher late lactation concentrations of IgG1 than did the other two groups. However, treatment mean isotype concentrations were always within normal ranges, except for IgG2 from the 10.3 mg/d group, which were higher. The practical significance of elevated serum Ig concentrations observed in the present study is not known. However, the present data do show that bST administered at doses that increased milk yield had no apparent detrimental effect on humoral immunity as measured by blood concentrations of Ig.

Analysis of Variance↗
PubMed1991

Levels of essential and other fatty acids in plasma and red cell phospholipids from normal controls and patients with atopic eczema.

Blood samples were collected from 48 atopic eczema patients and 33 normal subjects in Bristol, and from 434 normal individuals worldwide. In the plasma phospholipids in the atopic eczema patients, the concentrations of linoleic acid and the ratio of linoleic acid to its metabolites were significantly elevated as compared with both sets of controls. In the atopic eczema patients there were major abnormalities in the red cell phospholipids with saturated and monounsaturated fatty acids being significantly elevated and the concentrations of most essential fatty acids being significantly reduced. Patients with atopic eczema thus show abnormalities related both to desaturation of essential fatty acids and to their incorporation into red cell membranes.

Canada↗
PubMed1991

Antiphospholipid syndrome and cutaneous vasoocclusive disorders.

The antiphospholipid syndrome (characterized by the presence of circulating lupus anticoagulants or anticardiolipin antibodies) was first recognized in patients with systemic lupus erythematosus (SLE), but the syndrome can also exist in the absence of SLE. The clinical features include arterial or venous thrombosis, recurrent abortion, neurological problems, and various cutaneous disorders including thrombophlebitis, livedo reticularis, atrophie blanche, leg ulcers, and gangrene. In some cases, antiphospholipid antibodies may play a role with other recognized syndromes characterized by vascular occlusion, such as Sneddon's syndrome (livedo reticularis with cerebrovascular occlusion) and Degos' disease.

Antiphospholipid Syndrome↗
PubMed1990

Essential-fatty-acid metabolites in plasma phospholipids in patients with ichthyosis vulgaris, acne vulgaris and psoriasis.

The concentration of essential fatty acids (EFAs) and their metabolites in plasma phospholipids were measured by gas chromatography in normal individuals, and in patients with ichthyosis vulgaris, acne vulgaris or psoriasis. In all three patient groups, concentrations of arachidonic acid (20:4 omega 6) and docosapentaenoic acid (22:5 omega 6) were significantly below those in controls, suggesting that these abnormalities may occur in many skin diseases. Concentrations of dihomogammalinolenic acid (20:3 omega 6) were low in ichthyosis, normal in acne and elevated in psoriasis. Thus ichthyosis, acne and psoriasis each had a characteristic pattern of EFA metabolites.

Acne Vulgaris↗
PubMed1990

Sjögren's syndrome in systemic sclerosis. A clinical study of 26 patients.

Features of Sjögren's syndrome were sought in 26 patients with systemic sclerosis and in age- and sex-matched control subjects. The assessments included a structured history to establish symptoms of dry eyes and dry mouth. Schirmer's I and II tear tests. Rose Bengal staining with slit lamp microscopy of the eyes, measurement of basal and stimulatory salivary secretion. We measured sweat secretion rates from the skin. Salivary scintigraphy and skin biopsies were performed on the patients. Only one patient showed the complete picture of Sjögren's syndrome with both clinical and investigational evidence of lacrimal and salivary gland involvement. A further patient had an abnormal Schirmer's II test and xerostomia with reduced salivary secretion and an abnormal scan, but no ocular symptoms and no keratoconjunctivitis sicca on ophthalmological examination. Two patients had reduced salivary flow and a dry mouth. A number of patients and control subjects showed various individual symptoms and signs of lacrimal and salivary disorders. These features alone are not sufficient for the diagnosis of Sjögren's syndrome. There is a clear need to adopt strict criteria for diagnosing the condition. The association of Sjögren's syndrome with systemic sclerosis seems doubtful and if it does occur it is very much less common than previously suggested.

Adult↗
PubMed1990

Overall efficacy of chronically administered recombinant bovine somatotropin to lactating dairy cows.

Recombinant bST at daily dosages of 0, 10.3, 20.6, and 41.2 mg/d were injected for 266 d into 8, 10, 9, and 9 Holstein cows, respectively. Treatment effects of recombinant bST were assessed for milk production traits, BW, blood components, and health and reproductive variables. Data reported compare controls to all bST-treated cows. There was an average increase of 18% in 3.5% FCM for bST versus control cows. This increase resulted in enhanced feed efficiency for bST cows, as their DM intakes were not elevated above those of the control cows. Recovery of BW was similar between control and bST groups. Milk composition was unaffected except for a slight decrease in protein percentage during the first 9 wk of treatment, and an elevated SCC between wk 19 and 28. Blood parameters were not different between control and bST cows, except for hematocrit, which decreased with bST treatment. The only health and reproductive parameters affected by bST were mastitis and days open, which were increased in the highest dosage groups.

Animals↗