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Notes: Summary Viral infection is assumed to trigger or exacerbate autoimmune responses against pancreatic beta cells leading to the development of insulin-dependent diabetes mellitus (IDDM). We therefore examined by polymerase chain reaction the presence of two candidate viruses, cytomegalovirus and Epstein-Barr virus, in IDDM pancreases. Pancreas tissues were obtained by biopsy under laparoscopy from 16 recent-onset IDDM patients: age 17–53 years; disease duration 0–7 months; six had flu-like symptoms before onset. Frozen sections were made and subjected to DNA amplification. DNA samples were prepared from the frozen sections and polymerase chain reaction was performed using primers specific to cytomegalovirus, Epstein-Barr virus and control gene for HLA-DP. Cytomegalovirus- and Epstein-Barr virus-infected cells were used for positive control. Southern blot analysis could detect cytomegalovirus DNA from as few as 2×10−1 cytomegalovirus-infected cells and Epstein-Barr virus DNA from two Epstein-Barr virus-infected cells. This highly sensitive analysis, however, could not detect cytomegalovirus or Epstein-Barr virus genomes in pancreases of recent-onset IDDM. A single copy human gene (HLA-DP) was amplified from all IDDM pancreases indicating that DNA amplification was performed without inhibition. We conclude that cytomegalovirus or Epstein-Barr virus genomes are unlikely to exist in pancreas biopsy specimens of recent-onset IDDM patients.

Notes: Summary Cytokines are thought to contribute to the induction of pancreatic beta-cell destruction in insulin-dependent diabetes mellitus. The molecular mechanisms that underlie beta-cell death were investigated by studying cytokine-induced cell death in beta-cell lines. A combination of three cytokines (interleukin-1β, tumour necrosis factor-α, and interferon-γ) induced apoptotic cell death in the mouse pancreatic beta-cell line βTC1, as judged from the appearance of cells with hypodiploid nuclei and oligonucleosomal DNA fragmentation. The same treatment also induced apoptosis in the mouse pancreatic alpha-cell line αTC1 and the NOD/Lt mouse beta-cell line NIT-1, although to a lesser extent than in βTC1 cells. The abundance of endogenous Bcl-2 in βTC1 cells was lower than that in the other two cell lines. Overexpression of human Bcl-2 in βTC1 cells partially protected them from cytokine-induced cell death. These results suggest that apoptosis may be responsible, at least in part, for cytokine-induced beta-cell destruction and that Bcl-2 prevents apoptosis in pancreatic islet cells. [Diabetologia (1996) 39: 530–536]

Notes: Summary We investigated the presence of retroviral protein in the pancreatic islets of non-obese diabetic mice to prove that the virus-like particle observed specifically in the pancreatic Beta cell of these mice was retrovirus. Western blot analysis probed with anti-retrovirus antibody demonstrated the existence of retroviral gag (group specific antigen) protein p30 in the islets of female non-obese diabetic mice. Islets of non-obese diabetic mice which were treated with cyclophosphamide, known to accelerate the development of insulitis and diabetes mellitus, have shown both a significantly increased number of retrovirus-like particles (type C) and enhanced expression of gag protein p30, compared to those of mice not treated with cyclophosphamide. These results confirmed the presence of type C retrovirus in non-obese diabetic mouse Beta cells and suggest a role for retrovirus in the development of insulitis and diabetes in these mice.

Notes: Summary Viral infection is assumed to trigger or exacerbate autoimmune responses against pancreatic beta cells leading to the development of insulin-dependent diabetes mellitus (IDDM). We therefore examined by polymerase chain reaction the presence of two candidate viruses, cytomegalovirus and Epstein–Barr virus, in IDDM pancreases. Pancreas tissues were obtained by biopsy under laparoscopy from 16 recent-onset IDDM patients: age 17–53 years; disease duration 0–7 months; six had flu-like symptoms before onset. Frozen sections were made and subjected to DNA amplification. DNA samples were prepared from the frozen sections and polymerase chain reaction was performed using primers specific to cytomegalovirus, Epstein–Barr virus and control gene for HLA-DP. Cytomegalovirus- and Epstein–Barr virus-infected cells were used for positive control. Southern blot analysis could detect cytomegalovirus DNA from as few as 2 × 10–1 cytomegalovirus-infected cells and Epstein–Barr virus DNA from two Epstein–Barr virus-infected cells. This highly sensitive analysis, however, could not detect cytomegalovirus or Epstein–Barr virus genomes in pancreases of recent-onset IDDM. A single copy human gene (HLA-DP) was amplified from all IDDM pancreases indicating that DNA amplification was performed without inhibition. We conclude that cytomegalovirus or Epstein–Barr virus genomes are unlikely to exist in pancreas biopsy specimens of recent-onset IDDM patients. [Diabetologia (1995) 38: 667–671]

Notes: Summary Cytokines are thought to contribute to the induction of pancreatic beta-cell destruction in insulin-dependent diabetes mellitus. The molecular mechanisms that underlie beta-cell death were investigated by studying cytokine-induced cell death in beta-cell lines. A combination of three cytokines (interleukin-1Β, tumour necrosis factor-α, and interferon-γ) induced apoptotic cell death in the mouse pancreatic beta-cell line ΒTC1, as judged from the appearance of cells with hypodiploid nuclei and oligonucleosomal DNA fragmentation. The same treatment also induced apoptosis in the mouse pancreatic alpha-cell line αTC1 and the NOD/Lt mouse beta-cell line NIT-1, although to a lesser extent than in ΒTC1 cells. The abundance of endogenous Bcl-2 in ΒTC1 cells was lower than that in the other two cell lines. Overexpression of human Bcl-2 in ΒTC1 cells partially protected them from cytokine-induced cell death. These results suggest that apoptosis may be responsible, at least in part, for cytokine-induced beta-cell destruction and that Bcl-2 prevents apoptosis in pancreatic islet cells.

Notes: Abstract Objectives: The present study was conducted to compare pharmacokinetic behaviors of nicardipine enantiomers given in different doses with different formulations of racemic nicardipine in healthy volunteers. Methods: One or two 20-mg racemic nicardipine tablets, and a 40-mg sustained-release capsule of nicardipine were administered to eight healthy volunteers in a cross-over fashion and pharmacokinetic parameters were evaluated. Enantiomer concentrations were determined by GC-MS combined with chiral stationary phase HPLC. Results and conclusions: Serum concentration of (+)-nicardipine was approximately 2–3 times higher than that of (−)-nicardipine in 20- and 40-mg doses of conventional formulations and a non-linear increase in bioavailability with dose was demonstrated. The value for AUC of (+)-nicardipine was approximately 2.3–2.8 times greater than that of the (−)-nicardipine (P 〈 0.05) when 20 and 40 mg racemic nicardipine were administered in a conventional preparation. Relative bioavailability of the sustained-release preparation vs the conventional preparation was 28% and 44% for (+)- and (−)-nicardipine, respectively, for the 40-mg dose.

Notes: Abstract A fourteen month-old boy with atypical phenylketonuria was treated with 5-hydroxytryptophan, L-dopa and peripheral aromatic amino acid decarboxylase inhibitor (Ro 4-4602:benserazide). Despite the good control of plasma phenylalanine on a low phenylalanine diet, he had shown no improvement in his development but progressive neurological symptoms, such asiirritability, convulsions and decrease voluntary movement. After beginning neurotransmitter therapy, his irritability disappeared promptly and the other symptoms diminished. He gradually reached his developmental milestones. At two and a half years of age, he had recovered sufficiently to be able to walk freely on treatment with 13 mg/kg/day of 5-hydroxytryptophan, 11 mg/kg/day of L-dopa and 2.7 mg/kg/day of benserazide in combination with slight restriction of phenylalanine intake (100 mg/kg/day). Levels of serotonin and 5-hydroxyindoleacetic acid were low in the patient's CSF. His urinary biopterin (Crithidia factor) excretion was low. An increase in serum biopterin following L-phenylalanine loading was not found. Dihydropteridine reductase activity in his skin fibroblasts was normal. He excreated large amounts of erythro- and threo-neopterins (but only a trace of biopterin) in his urine. After loading with phenylalanine the urinary excretion of neopterins was even more enhanced, but biopterin remained at low levels. These findings indicated that the patient has a dihydrobiopterin synthetase deficiency.

Notes: We present a new method to evaluate the photo-oxidative activity of sunscreening agents based on the photodynamic oxidation of uric acid. Uric acid was selected as the oxidant probe for its high reactivity to singlet oxygen and oxygen radicals, high sensitivity of detection using electrochemical (EC) techniques, low light absorptivity and high photochemical stability in the UVA/B region of interest, and stability to autoxidation. The method is demonstrated by the photodynamic oxidation of uric acid on co-irradiation with Rose Bengal, a highly efficient photosensitizing dye for the production of singlet oxygen (1O2). Using this assay we found that the relative photodynamic oxidation rates of UVB-absorbing sunscreens in 80% methanol on irradiation with 〉290 nm light decreased in the order 2-ethylhexyl 4-dimethylaminobenzoate (DMABA-2EH) ≫ 2-ethylhexyl 4-methoxycinnamate (MCA-2EH) and the experimental sunscreens, 1-(1,1-dimethylethyl)-3-octanoyl-4,4-dimethyl- 1,4,5,6,-tetrahydropyridine (ICI-319) and 1-(2-methylpropyl)-3-propionyl-4,4-dimethyl-1,4,5,6-tetrahydropyridine (ICI-855). The relative photodynamic oxidation rates of UVA-absorbing sunscreens decreased in the order 4-tert-butyl-4'-methoxydibenzoylmethane (BMDBM) and 4-(2-propyl)benzophenone (PB) 〉 2-hydroxy-4'-methoxy-benzophenone (HMB) and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB). We have confirmed the photodynamic activity of DMABA-2EH for the production of singlet oxygen (1O2) using electron paramagnetic resonance (EPR) spectroscopy and the reagent 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP). We failed to detect the photodynamic production of the oxyradicals, superoxide (O2.-) and hydroxyl radical (HO.) using N-tert-butyl-a-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrrolidine-1-oxide (DMPO) as a result of photochemical interference caused by these spin-trapping reagents. The uric acid photo-oxidation assay was also used to compare the photodynamic reactivity of light-reflective, microfine oxides TiO2, ZnO and ZrO2 suspended in aqueous 80% methanol. All of the microfine oxides (uncoated) showed greater photodynamic reactivity in equimolar dispersion than did any of the organic UVA- and UVB-absorbing sunscreens in homogeneous solution. In this assay the photodynamic oxidation rates for the microfine oxides decreased in the order ZnO ≫ TiO2 (anatase) 〉 ZrO2 〉 TiO2 (rutile). Resume Nous presentons un nouveau procede d'evaluation de l'activite photooxydante d'agents pour ecrans solaires base sur l'oxydation photodynamique de l'acide urique. L'acide urique a ete choisi comme test a l'oxydation en raison de sa forte reactivite a l'oxygene singulet et aux radicaux oxygene, sa haute sensibilite a la detection par les techniques electrochimiques (EC), sa faible capacite d'absorption de la lumiere, sa stabilite photochimique elevee dans le domaine UVA/UVB concerne, et sa stabilite a l'autooxydation. La demonstration du procede est effectuee au travers de l'oxydation photodynamique de l'acide urique co-irradie avec du Rose du Bengale, colorant phosensibilisateur tres efficace pour generer de l'oxygene singulet (1O2). En mettant ce test en oeuvre nous avons trouve que les vitesses relatives d'oxydation photodynamique d'ecrans solaires aux UVB dans due methanol a 80%, irradies avec une lumiere 〉 290nm, diminuent dans l'ordre: 2-ethylhexyl 4-dimethylamino-benzoate (DMABA-2EH) ≫ 2-ethylhexyl 4-methoxycinnamate (MCA-2EH) et les ecrans a l'essai: la 1-(1,1-dimethylethyl)-3-octanoyl-4,4-dimethyl-1,4,5,6-tetrahydopyridine (ICI-319) et la 1-(2-methylpropyl)-3-propionyl-4,4-dimethyl-1,4,5,6-tetrahydropyridine (ICI-855). les vitesses relatives d'oxydation photodynamique d'ecrans solaires aux UVA diminuent dans l'ordre: 4-tert-butyl-4'-methoxydibenzoylmethane (BMDBM) et 4-(2-propyl) benzophenone (PB) 〉 2-hydroxy-4'-methoxybenzophenone (HMB) et 2'2'-dihydroxy-4-methoxybenzophenone (DHMB). Nous avons confirme l'activite photdynamique du DMABA-2EH pour la production d'oxygene singulet (1O2) en utilisant la spectroscopie par resonance paramagnetique electronique et le reactif 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP). Nous n'avons pas pu detecter la production photodynamique des oxyradicaux du superoxyde (O2.) et du radical hydroxyle (HO.) a l'aide de la N-ter-butyl-a- phenylnitrone (PBN) en raison d'interferences photochimiques causees par ces reactifs spin-Bloquants. Le test de photooxydation de l'acide urique a aussi ete utilise pour comparer la reactivite photodynamique d'oxydes microfins reflechisseurs de lumiere TiO2, ZnO et ZrO2 en suspension dans du methanol aqueux a 80%. Tous ces oxydes microfins (non enrobes) ont montre une meilleure reactivite photodynamique en dispersion equimolaire que ne l'a fait aucun des ecrans solaires aux UVA et UVB en solution homogene. Lors de ce test les vitesses d'oxydation photodynamique des oxydes microfins ont diminue dans l'ordre ZnO ≫ TiO2 (anatase) 〉 ZrO2 〉 TiO2 (rutile).