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Biomedical subjects

R F James

Publications and source records attributed to R F James.

At least 55 records · Page 3Linked to original sources
PubMed1996

Development and optimization of the human allogeneic mixed lymphocyte islet (MLIC) and acinar (MLAC) coculture system.

Although human islet allotransplantation has been shown to be effective in restoring normoglycaemia to diabetic recipients, the long-term success rate is relatively low. The poor results of human islet transplantation are surprising given the relative ease of establishing functioning islet allografts in rodent models with minimal immunosuppression and have been attributed to a number of factors of which rejection may play a major part. The impracticality of studying the immunogenicity of human islets in vivo has led us to develop a model specifically to study the allogeneic immune response to the major components of isolated human islet preparations. To try and overcome the variability associated with this methodology, this study was designed to develop and optimize the mixed lymphocyte coculture as an in vitro model for the initial alloresponse to both freshly isolated intact human islets (MLIC) and acinar tissue pieces (MLAC). For this, titration of the islets and acinar tissue, as well as kinetic studies of the response, were used to select optimum conditions for the MLIC which were shown to be ten islets and ten acinar tissue pieces with a coculture duration of 7-9 days. The optimized studies included the use of non-tissue culture microwells to deter fibroblast growth, RPMI + 10% human AB serum to reduce the background lymphocyte response and a low concentration of dithizone to stain the islets prior to handpicking. Freshly isolated human islets were found to stimulate allogeneic lymphocytic proliferation; however, differences in the relative response to islets and acinar tissue led us to test the effect of soluble products from the acinar cells on lymphocyte proliferation in the mixed lymphocyte reaction. An inhibitory effect of the soluble products of acinar cells on the allogeneic lymphocyte proliferative response was found to contribute to the reduced response of the MLAC compared to the MLIC. Human islets were shown to stimulate an allogeneic immune response in vitro, and this MLIC model provides a method for assessing the specific immunogenicity of human isolated islet preparations and associated acinar tissue in transplantation.

Coculture Techniques↗
PubMed1996

Loss of functional KATP channels in pancreatic beta-cells causes persistent hyperinsulinemic hypoglycemia of infancy.

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is a disorder of childhood associated with inappropriate hypersecretion of insulin by the pancreas. The pathogenesis of the condition has hitherto remained controversial. We show here that insulin-secreting cells from a homogeneous group of five infants with PHHI lack ATP-sensitive K+ channel (KATP) activity. As a consequence, PHHI beta-cells are spontaneously electrically active with high basal cytosolic Ca2+ concentrations due to Ca2+ influx. Our findings define the pathogenesis of this disease as a novel K+ channel disorder.

ATP-Binding Cassette Transporters↗
PubMed1996

The effect of insulin treatment and of islet transplantation on the resistance artery function in the STZ-induced diabetic rat.

1. This study was designed to investigate the influence of insulin treatment and islet transplantation on the smooth muscle contractility and endothelium-dependent and independent relaxation of resistance arteries in the chemically induced streptozotocin (STZ) diabetic rat after 6-8 weeks, and 12-14 weeks of diabetes, compared to non-diabetic age-matched controls. 2. The morphology, and contractile responses to high potassium physiological salt solution (KPSS), KPSS containing 10(-5) M noradrenaline (NAK), and concentration-response curves to noradrenaline (NA) of mesenteric resistance arteries were recorded, along with the endothelium-dependent relaxation responses to acetylcholine (ACh) and bradykinin (BK), and endothelium-independent relaxation to sodium nitroprusside (SNP). Concentration-response curves were then repeated in the presence of a nitric oxide synthase inhibitor, NG-nitro-L-arginine (L-NOARG). 3. Insulin-treated diabetic rats in the 12 week study demonstrated enhanced vascular contractility to KPSS, NAK and NA, compared to age-matched non-diabetic controls. 4. Incubation with L-NOARG resulted in both a significant increase in maximum contractile response, and sensitivity (pD2) to NA in the untreated diabetic group (6 weeks). A significant shift in sensitivity was also seen in the insulin-treated diabetic group. In the 12 week study, incubation with L-NOARG resulted in an increased maximum contractile response and sensitivity to NA in the insulin-treated diabetics. An increase in sensitivity was also observed in the untreated diabetic group. 5. Endothelium-dependent relaxation to ACh was significantly augmented in the untreated diabetics (6-weeks), compared to the control group. In the 12-week study, relaxation to both ACh and BK was not significantly different in any of the experimental groups when compared to the sham-operated non-diabetic controls. 6. Incubation with L-NOARG resulted in a significant attenuation of the maximum relaxation response to ACh and BK in all of the experimental groups, in the 6- and the 12-week study. 7. There was no significant difference in the maximum relaxation response or sensitivity to sodium nitroprusside between the diabetic groups and their age-matched controls in either the 6-week or the 12-week study. 8. The results of this study suggest an enhanced release of nitric oxide in the early stages of diabetes, which is more evident in the untreated diabetic rats than the insulin treated, and appears to normalize as the duration of diabetes progresses. This study also shows that the alteration in vascular reactivity of the resistance arteries can be restored to within normal limits by the transplantation of islets of Langerhans, and that islet transplantation is an effective strategy in the correction of the metabolic abnormalities associated with insulin-dependent diabetes.

Analysis of Variance↗
PubMed1996

Ionic control of beta cell function in nesidioblastosis. A possible therapeutic role for calcium channel blockade.

A preterm female infant presented with intractable hypoglycaemia within 10 minutes of delivery. Normoglycaemia could be maintained only by the intravenous infusion of glucose at a rate of 20-22 mg/kg/min. Persistent hyperinsulinaemic hypoglycaemia of infancy was diagnosed from an inappropriately raised plasma insulin concentration (33 mU/l) at the time of hypoglycaemia (blood glucose < 0.5 mmol/l). Medical treatment with glucagon, somatostatin, and diazoxide led to only a modest reduction in the intravenous glucose requirement; a 95% pancreatectomy was performed and histological 'nesidioblastosis' confirmed. In vitro electrophysiological studies using patch clamp techniques on isolated pancreatic beta cells characterised the ionic basis for insulin secretion in nesidioblastosis. The beta cells were depolarised in low ambient glucose concentrations with persistently firing action potentials; these were blocked reversibly by the calcium channel blocking agent verapamil. Persistent postoperative hyperinsulinaemic hypoglycaemia was treated with oral nifedipine. This increased median blood glucose concentrations from 3.5 to 4.8 mmol/l and increased in duration the child's tolerance to fasting from 3 to 10.5 hours. These data allude to an abnormality in the ionic control of insulin release in nesidioblastosis and offer a new logical approach to treatment which requires further evaluation.

Blood Glucose↗
PubMed1996

Presence of neuropeptide Y and its messenger ribonucleic acid in human islets: evidence for a possible paracrine role.

Neuropeptide Y (NPY) has been shown to decrease insulin secretion from rodent islets. NPY messenger ribonucleic acid (mRNA) has been demonstrated in rat and mouse pancreatic islets. We, therefore, examined human islets for the presence of NPY-encoding mRNA and NPY-like immunoreactivity. Human pancreatic islets were obtained from cadaveric organ donors, using collagenase digestion and purification on BSA density gradients. Northern blot analysis, employing a human NPY riboprobe, revealed specific NPY-encoding mRNA in the islet. Compared to the islet, NPY message abundance was 9-fold higher in the caudate nucleus and 2.4-fold higher in the temporal lobe, but it was 75% lower in the adrenal gland. NPY-like immunoreactivity was present at 2.4 +/- 0.3 fmol/microgram protein in acid-ethanol extracts from the islets. On fast protein liquid chromatography with a reverse phase column, the majority of NPY-like immunoreactivity eluted as a peak with a retention time identical to that of porcine NPY standard. Added NPY (100 nmol/L) decreased (P = 0.001) glucose-stimulated (8 mmol/L) insulin release from the human islets by 45% in a perfusion system. Therefore, human islets synthesize substantial amounts of NPY, which could act as an intra-islet paracrine regulator.

Adolescent↗
PubMed1996

Expression of alpha 2- and beta-adrenoceptor subtypes in human islets of Langerhans.

Sequences from cDNA molecules encoding alpha 2-adrenoceptor subtype genes were subcloned into prokaryotic vectors and riboprobes generated to hybridise selectively with each of the human alpha 2C2-, alpha 2C4- and alpha 2C10-adrenoceptor subtype mRNA species. The riboprobes were labelled with either 32P or digoxigenin and used to study the expression of alpha 2-adrenoceptor subtypes in sections of human pancreas, in isolated human islets of Langerhans and in clonal HIT-T15 pancreatic beta-cells. Using a ribonuclease protection assay protocol, expression of mRNA species encoding both alpha 2 C2 and alpha 2 C10 was demonstrated in preparations of isolated human islets of Langerhans. mRNA encoding alpha 2C4 was also detected in human islet RNA, using reverse transcription coupled with the polymerase chain reaction. In situ hybridisation was then employed to examine the distribution of each alpha 2-adrenoceptor subtype in sections of human pancreas. All three subtypes of alpha 2-adrenoceptor mRNA were identified in sections of formalin-fixed, paraffin-embedded human pancreas using riboprobes labelled with digoxigenin. Although some labelling of the three alpha 2-adrenoceptor mRNA subtypes was seen in the islets, the labelling was most intense in the exocrine tissue of the pancreas for each receptor subtype. The specificity of the digoxigenin-labelled RNA probes was confirmed in several control tissues and by in situ hybridisation studies using sense probes in the pancreas. The integrity of the pancreas sections was confirmed by in situ hybridisation with an antisense riboprobe derived from human insulin cDNA. The results demonstrate that multiple alpha 2-adrenoceptor subtypes are expressed in human pancreas. Both the exocrine and endocrine cells express more than one receptor subtype, although the islets stain less intensely than the bulk of the tissue suggesting that the islet cells may have lower levels of expression than the acinar tissue. The presence of alpha 2-adrenoceptor subtype mRNA species in pancreatic beta-cells was confirmed by Northern blotting of RNA extracted from the clonal beta-cell line, HIT-T15. Transcripts encoding each of the three cloned alpha 2-adrenoceptor subtypes were detected in HIT-T15 cells. Hybridisation of sections of human pancreas with oligodeoxynucleotide probes designed to hybridise with beta 2-adrenoceptor mRNA revealed expression of this species in islet beta-cells but not in the exocrine tissue of the pancreas.

Base Sequence↗
PubMed1996

Control of islet intercellular adhesion molecule-1 expression by interferon-alpha and hypoxia.

The ability of interferon-alpha (IFN-alpha) to induce the adhesion molecules that characterize the islets of patients with type I diabetes has been investigated. We have found that all tested recombinant IFN-as will induce major histocompatibility complex (MHC) class I on arterial endothelial cells. Some but not all IFN-as will induce intercellular adhesion molecule-1 (ICAM-1). However, there is only a transient and modest increase in VCAM on arterial endothelial cells. IFN-alpha has very little effect on endothelial MHC class II expression but will induce these proteins on monocytes. Thus, there is a close concordance between the biological actions of IFN-alpha and the appearance of those adhesion molecules induced in the islets of patients with type I diabetes. IFN-alpha is also produced in normal human islets during short-term cultures, probably as a result of the ischemia present at the center of the islet. This induction of IFN-alpha by hypoxia may explain the previously reported spontaneous induction of ICAM-1 in human islets and may also be a contributing factor to the failure of islet grafts.

Arteries↗
PubMed1995

Functional studies of rat, porcine, and human pancreatic islets cultured in ten commercially available media.

There have been no extensive studies investigating the effect of tissue culture media on the in vitro functional characteristics of rat, porcine and human Islets of Langerhans. We therefore aimed to compare ten commercially available tissue culture media on the basis of their ability to maintain islet viability. Following isolation, islets were cultured free-floating in the ten media (RPMI 1640-11mM glucose (control), RPMI 1640-2.2mM glucose, Dulbecco's MEM, TCM 199, CMRL 1066, Iscove's MEM, Waymouth's MEM, Serum-Free medium, Ex-cell 300, Ham's F-12) and viability was assessed after 24 hr, 3 days, and 7 days on the basis of macroscopic appearance, cell membrane integrity, and insulin secretion in response to glucose stimulation both by dynamic incubation and by perifusion. Each islet species demonstrated physiological insulin release characteristics in all media--however, it was possible to distinguish between the media by comparing the stimulation indices calculated from the insulin release studies. Significantly higher stimulation indices were produced in Iscove's MEM for rat islets, in Ham's F-12 for porcine islets and in CMRL 1066 for human islets. Over the entire culture period a significant deterioration in function was observed in all species cultured in the control media, although this was reversed when islets were cultured in the optimal media. Furthermore, in the case of porcine and human islets a significant improvement in function over the seven-day period was noted in the optimal media. In conclusion, of the commercially available media, the optimal tissue culture medium for rat islets is Iscove's MEM, for porcine islets is Ham's F-12, and for human islets is CMRL 1066.

Animals↗
PubMed1995

Generation of a monoclonal antibody that recognizes the amino-terminal decapeptide of the B-subunit of Escherichia coli heat-labile enterotoxin. A new probe for studying toxin assembly intermediates.

Cholera toxin and the related Escherichia coli heat-labile enterotoxin are hexameric proteins comprising one A-subunit and five B-subunits. In this paper we report the generation and characterization of a monoclonal antibody, designated LDS47, that recognizes and precipitates in vivo assembly intermediates of the B-subunit (EtxB) of E. coli heat-labile enterotoxin. The monoclonal antibody is unable to precipitate native B-subunit pentamers, thus making LDS47 a useful probe for studying the early stages of enterotoxin biogenesis. The use of LDS47 to monitor the in vivo turnover of newly synthesized B-subunits in the periplasm of E. coli demonstrated that (i) the turnover of unassembled B-subunits followed an apparent first order process and (ii) it occurred concomitantly with the assembly of native B-pentamers (k = 0.317 +/- 0.170 min-1; t1/2 = 2.2 min). No other proteins were co-precipitated with the newly synthesized B-subunits; a finding that implies that unassembled B-subunits do not stably associate with other periplasmic proteins prior to their assembly into a macromolecular complex. The use of overlapping synthetic peptides corresponding to the entire EtxB polypeptide demonstrated that the epitope recognized by LDS47 is located within the amino-terminal decapeptide of the B-subunit. From the x-ray structural analysis of the toxin (Sixma, T., Kalk, K., van Zanten, B., Dauter, Z., Kingma, J., Witholt, B., and Hol, W. G. J. (1993) J. Mol. Biol. 230, 890-918), this region appears to resemble a curved finger that clasps the adjacent B-subunit. Thus, this region might be expected to be exposed in the unfolded or unassembled subunit, but to become partially buried upon assembly and thus inaccessible to recognition by the monoclonal antibody.

Amino Acid Sequence↗
PubMed1995

Identification and characterization of a functional retinoic acid/thyroid hormone-response element upstream of the human insulin gene enhancer.

A deletion analysis of the human insulin gene extending to 2 kb upstream of the transcription start site provided evidence of regulatory sequences located upstream of the insulin-linked polymorphic region (ILPR). Within this ILPR-distal region is a sequence (Ink, for insulin kilobase upstream) which contains three potential nuclear hormone-receptor half-sites, closely matching the consensus sequence AGGTCA. These sequences are arranged as a palindromic element with zero spacing over-lapping a direct repeat with 2 bp spacing. The Ink sequence was used in electrophoretic mobility-shift assays within nuclear extracts from COS-7 cells overexpressing the vitamin D, thyroid hormone or retinoic acid receptors, or from an insulin-expressing hamster cell line, HIT-T15. These studies suggest that the insulin-expressing cell line contains thyroid hormone and retinoic acid receptors at least, and that these receptors are able to recognize the Ink sequence. Three copies of the Ink sequence were placed upstream of the thymidine kinase promoter and firefly luciferase reporter gene. In COS-7 cells expressing the appropriate nuclear hormone receptor, this construct was responsive to both thyroid hormone (18-fold) and all-trans-retinoic acid (31-fold). In HIT-T15 cells the same construct responded to all-trans-retinoic acid, but not to thyroid hormone. Within the context of a 2 kb insulin gene fragment, the Ink sequence was shown to be activated by retinoic acid and by the retinoic acid receptor, but acted as a negative element in the presence of both retinoic acid and the retinoic acid receptor. Mutagenesis studies demonstrated that the palindromic sequence was important for the retinoic acid response, and for binding of complexes containing retinoic acid receptor. In human islets of Langerhans, retinoic acid was shown to stimulate insulin mRNA levels. These results demonstrate that a functional nuclear hormone-receptor-response element is located upstream of the human ILPR. As retinoic acid and thyroid hormone are frequently involved in developmental regulatory processes, it is possible that this element may be important in the process of islet cell differentiation.

Animals↗
PubMed1995

Optimization of the magnetic field used for immunomagnetic islet purification.

Purification of islets based on the physical differences in density between exocrine and islet tissue reduces islet yields and remains one of the factors limiting islet transplantation. Immunomagnetic cell separation methods provide an attractive, highly specific alternative capable of rapid, gentle, high volume cell separation, but they require modification to be applied effectively to separation of the much larger tissue fragments involved in islet purification. In this study, mAb to rat exocrine tissue were coupled to 4.5-microns magnetic beads (M450 Dynabeads), before incubation with standard aliquots of rat pancreatic digest. The effect on immunomagnetic islet purification of modifications in the magnetic field and the method of digest release into the field were investigated. The results showed that using vibration to maintain the immunomagnetically labeled digest in suspension in tissue culture medium whose density had been increased by the addition of BSA, significantly improved the purification process. When the digest suspension was slowly released and allowed to drift under gravity through a magnetic field applied across a narrow tube, the use of a quadripole of permanent magnets improved results compared with bipolar or unipolar magnetic fields. By modifying immunomagnetic cell separation techniques in this way, a median islet yield of 77% could be reliably achieved while removing 88% of the contaminating exocrine tissue. The use of such methods in human islet purification would significantly increase the yield of islets from each donor pancreas and increase the success rate of transplantation from single donors.

Amylases↗
PubMed1995

Attachment, replication and thrombogenicity of genetically modified endothelial cells.

UNLABELLED: Endothelial cell seeding of prosthetic surfaces has been proposed as a technique to improve the patency of vascular grafts following arterial reconstruction. The introduction of specific recombinant DNA into seeded endothelial cells may enhance the anti-thrombogenic nature of the endothelial-blood interface with a consequent reduction in graft thrombosis. However, the successful use of genetically modified endothelial cells in the seeding process relies on the cells retaining normal function in terms of cellular replication, attachment and secretion of anti-thrombotic mediators. Successful genetic manipulation of human endothelial cells has been accomplished by viral and chemical methods. AIM: To study the functional characteristics of electrontransfected endothelial cells. METHODS AND RESULTS: Endothelial cells were electro-transfected with the test plasmid pTCF at a transfection efficiency of 10% utilising a single electric pulse with an electric field of 1000 volts/cm and a time constant of 12.8ms. The functional status of transfected endothelial cells was then compared with a control endothelial cell population. There were no significant differences in replication (p = 0.76), attachment (p = 0.43), basal (p = 0.89) or stimulated (p = 0.11) prostacyclin release between transfected cells as compared with control endothelial cells. CONCLUSIONS: Genetically modified cells are functionally normal, and may be used in endothelial cell seeding of prosthetic vascular surfaces.

Blood Vessel Prosthesis↗
PubMed1995

Immunomodulation of cultured vascular endothelial cells by serial cell passage.

UNLABELLED: Endothelial cell seeding has been successful in reducing the thrombogenecity of prosthetic vascular grafts in animal models, but results from clinical trials have been largely disappointing. These poor results have been associated with poor graft coverage in immediate seeding trials, and failure of cell culture in staged procedures. These problems could be largely overcome by utilising a bank of allogeneic endothelial cells, providing an ever ready supply. However, one potential pitfall with this technique would be the possibility of a rejection response following transplantation. AIM: To study the effects of prolonged tissue culture, on the ability of endothelial cells to generate an immune response. METHODS AND RESULTS: The immunogenecity of human umbilical vein endothelial cells was measured using the mixed lymphocyte endothelial reaction. It was demonstrated that prolonged tissue culture significantly reduced the immunogenecity of the cells, from a mean of 7261 cpm (S.E. +/- 243, n = 3) for cells of subculture 3, to 5478 cpm (+/- 156, p = 0.04) for cells of subculture 7 (p = 0.04, Wilcoxon paired rank test), but did not significantly impair morphology or antithrombotic function. CONCLUSION: This study provides evidence that prolonged tissue culture provides morphologically and functionally intact, immunomodified endothelial cells which may potentially be used in seeding prosthetic vascular grafts.

Blood Vessel Prosthesis↗
PubMed1995

Optimisation of gene transfer into vascular endothelial cells using electroporation.

OBJECTIVES: We have examined the conditions required to obtain optimum transfection efficiencies for human umbilical vein endothelial cells by transduction with a plasmid conferring neomycin resistance. MATERIALS AND METHODS: Preliminary studies examined the effects of electric discharges using the Biorad Gene Pulser on endothelial cells. Post-electroporation, there was a significant decrease in cell survival with increasing voltages (100-400 volts; p = 0.03), capacitances [125-960 microFarads (microF); p = 0.02], number of electric pulses (1-2; p = 0.03) and decreasing cell concentrations (p = 0.01). The optimal cell concentration was 3 x 10(6) cells/ml. Transfection studies utilised the neomycin resistance expressing plasmid, pTCF; transfectants were selected with the neomycin analogue G-148. RESULTS: Electro-transfection was optimised with increasing voltages (p = 0.02) and capacitances (p = 0.01) using a single pulse. Optimal transfection was obtained using 400 volts with a capacitance of 960 microF using a single pulse; the median transfection efficiency was 10%. Transduced endothelial cells stably expressed the plasmid for 12 days and at least two cell passages. CONCLUSIONS: The results indicate that endothelial cells can be efficiently transduced by electroporation to stably express an introduced gene. This may have important implications in vascular surgery.

Cell Survival↗
PubMed1995

Brain-reactive autoantibodies in BB/d rats do not recognize glutamic acid decarboxylase.

The BB rat spontaneously develops insulin-dependent diabetes mellitus (IDDM) similar to that in humans. The most practical markers of beta cell autoimmunity are circulating antibodies to islet cell components. In particular autoantibodies to the enzyme glutamic acid decarboxylase (GAD) are a common feature of IDDM development in humans. This study aims at investigating the prevalence and levels of autoantibodies in BB rats to antigens in a semipurified, GAD-enriched preparation from rat brain. Eighteen diabetes-prone BB/d rats (10 male and eight female) were tail bled weekly from age 28 days to 113 days and antibodies detected on the rat brain preparation by ELISA. Antibody levels were expressed as arbitrary units relative to a standard positive serum. Individual rats varied in the time and order of antibody appearance and IDDM onset, with the earliest occurrence being 42 days and 69 days, respectively. In some rats antibody production was maintained but declined in others. By 113 days 85% of diabetic rats had at some time been positive for autoantibodies to brain components, compared with 25% of non-diabetics (P = 0.09 by Fisher's exact test). Immunoabsorption studies using recombinant rat GAD-65 or recombinant human GAD-67 failed to inhibit the binding of BB rat sera to the original rat brain preparation. A capture ELISA using GAD-6 MoAb to capture GAD-65 from rat brain preparation or from a preparation of recombinant rat GAD-65, failed to detect anti-GAD antibodies in BB rats. Immunofluorescent staining of tissue sections showed the autoantibodies to be brain-specific, but having distinct staining patterns to the anti-GAD antibodies of Stiff Man Syndrome serum. In conclusion, BB rats possess autoantibodies reactive with rat brain antigens which may be associated with IDDM. However, these are not directed against GAD.

Animals↗
PubMed1995

Interferon expression in the pancreases of patients with type I diabetes.

We have used a reverse transcriptase-polymerase chain reaction (RT-PCR) protocol to examine the expression of cytokines in the pancreases and islets of patients with type I diabetes. We detect a significant increase in the level of expression of interferon (IFN)-alpha in the pancreases of the diabetic patients as compared with the control pancreases. In contrast, IFN-beta was detected at comparable levels in both groups, while IFN-gamma was detected in three of four control pancreases and one of four pancreases from the diabetic individuals. The IFN-alpha cDNAs generated by the RT-PCR were cloned and sequenced to determine which alpha-subtypes were being expressed. We found that the repertoire of subtypes was quite limited in any one individual (diabetic or not), although each individual was different with respect to the pattern of subtypes expressed. We also examined these pancreases for the expression of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-2, IL-4, and IL-6. We found no detectable expression of TNF-alpha or IL-2 in any pancreases, and the expression of the other cytokines was variable, with no pattern emerging from the comparison of the diabetic and nondiabetic individuals. We conclude that, of the cytokines examined, only IFN-alpha was significantly increased in the diabetic patients, a result that is consistent with the possibility that this cytokine is directly involved in the development of type I diabetes.

Adolescent↗