Protein kinase C expression in salivary gland acinar epithelial cells in non-obese diabetic mice,an experimental model for Sjögren''s syndrome

We planned to investigate the expression of protein kinase C (PKC) isoforms in acinar epithelial cells of salivary glands in the non-obese diabetic (NOD) mouse to find out if they develop changes of the PKC system like those seen in the human counterpart, i.e. in Sjögren's syndrome. Parotid, submandibular, and sublingual glands from NOD and control BALB/c mice were stained with a panel of monoclonal antibodies directed against conventional (, , and ), novel (, , and ), and atypical ( and ) PKC isoforms using the streptavidin/HRP method. Similarly to human labial salivary glands, acinar epithelial cells of the healthy control BALB/c mice contained two of the conventional PKC isoforms, and . Acinar and ductal epithelial cells also contained the atypical PKC isoforms and . PKC isoforms , , , and were not found. NOD mice which displayed focal sialadenitis contained the same conventional and atypical PKC isoforms. The acinar cells in NOD mice, in contrast to the Sjögren's syndrome patients, did not lack PKC or . On the contrary, PKC and staining was stronger than in the control BALB/c mice. The present results demonstrate that both conventional and atypical PKC isoforms participate in the salivary epithelial cell biology and that there are mouse strain-associated and/or disease state-associated changes in their expression. The lack of PKC and isoforms found in Sjögren's syndrome was not reproduced in NOD mice, which discloses one more difference between the human disease and its NOD mouse model.     

γ/δ Receptor-expressing T-cell clones from a cutaneous T-cell lymphoma suppress hematopoiesis

Summary Recently we described a cutaneous T-cell lymphoma expressing the / T-cell receptor [5]. The patient suffering from this lymphoma showed low numbers of myeloid and T cells in peripheral blood, while B and NK cells were relatively increased. In vitro culture of the patient's bone marrow (BM) cells revealed a significant suppression of myeloid/monocyte colony formation (GM-CFU) compared with normal controls. This was not due to infiltration of the BM with lymphoma cells. We speculated that a soluble factor either secreted or induced by the lymphoma cells might be responsible for the marked suppression of hematopoiesis in this patient. From a skin biopsy with infiltrating / T-lymphoma cells we established T-cell clones bearing the / T-cell receptor and resembling the phenotype of the lymphoma cells. The supernatant (SN) of these / T-cell clones reduced the number of colonies in a CFU-GM assay (using normal control BM) in comparison to SN of / T-cell clones established from the same biopsy. This suppression was seen mainly on day 7 of culture and was not neutralized by the addition of placenta-CM. The main mediator of this suppression seems to be IFN-,since it was detectable in high amounts in the SN of these / T-cell tumor clones as well as in the serum of the patient. In addition, anti-IFN- antibodies can reverse the T-cell SN-mediated suppression of CFU-GM. We conclude that high serum levels of interferon-, which is secreted in high amounts from / T-cells grown from a biopsy of a cutaneous lymphoma, can suppress hematopoiesis.Abbreviations TCR T-cell receptor - IFN- interferon- - SN supernatant - placenta CM placenta conditioned medium - BM bone marrow - CFU-GM myeloid/monocyte colony formation - NK cells natural killer cells - Ab antibody M. Wilhelm was supported by theDeutsche Forschungsgemeinschaft (DFG Wi 728-2)     

Expression and prognostic roles of integrins and interleukin-1 receptor type I in patients with ductal adenocarcinoma of the pancreas

To Investigate the prognostic indicator, we examined the expression of ₆- and ₅- integrin and interleukin-1 receptor type I (IL-1RI) immunohistochemically, and analyzed the correlation between immunohistochemical findings and clinicopathological factors in pancreatic cancer. In patients with a strongly expressing ₆- integrin subunit or weakly expressing ₅₁-integrin in pancreatic cancer tissues there was a significant association with advanced TNM stage (P = 0.027 and 0.014, respectively), presence of liver metastases (P = 0.032 and 0.002, respectively), and poor prognosis (P = 0.0155 and 0.0056, respectively). In patients with a weakly expressing ₆ integrin subunit or weakly expressing ₅₁-integrin in noncancerous pancreatic tissues there was a significant association with poor prognosis (P = 0.0324 and 0.0396, respectively). Multivariate analysis demonstrated that strong expression of ₆- and weak expression of ₅₁-integrin were found to be independent prognosticators in pancreatic cancer patients. Our present results indicate that ₆₁- and ₅₁-integrin expression can be a significant prognostic indicator in pancreatic cancer.     

Effect of intravenous glucose infusion on renal function in normal man and in insulin-dependent diabetics

Summary The effect of intravenous glucose infusion on glomerular filtration rate and renal plasma flow (constant infusion technique using ¹²⁵I-iothalamate and ¹³¹I-hippuran) and on urinary excretion of albumin and -2-microglobulin were studied in ten normal subjects and seven metabolically well-controlled insulin-dependent diabetics. Following glucose infusion in normal subjects (n = 10) blood glucose increased from 4.7±0.1 to 10.9±0.4 mmol/1 (SEM) (p 0.01). Glomerular filtration rate increased from 116±2 to 123±3ml/min x 1.73 m² (p 0,01), while no change in renal plasma flow was seen 552±11 versus 553±18 ml/min × 1.73 m². Volume expansion with intravenous saline infusion in six of the normal subjects induced no changes in blood glucose or kidney function. In seven strictly controlled insulin-dependent diabetics, blood glucose values were raised from 4.6±0.4 to 16.0±0.6 mmol/1 and clamped by means of an artificial beta cell. Glomerular filtration rate increased in all patients, from 133 ±5 to 140±6 ml/min × 1.73 m² (p 0.02), as did renal plasma flow from 576±26 to 623±38 ml/ min × 1.73 m² (p 0.02). Urinary albumin excretion remained unchanged in both normal subjects and diabetics. -2-microglobulin excretion rate increased significantly in the diabetics following glucose infusion, while no significant change was seen in the normal subjects. Our results show that hyperglycaemia per se contributes to the increased glomerular filtration rate and renal plasma flow in insulin-dependent diabetes.     

Mutations in the R-type pyruvate kinase gene and altered enzyme kinetic properties in patients with hemolytic anemia due to pyruvate kinase deficiency

Summary The biochemical properties of erythrocyte pyruvate kinase (PK) together with mutations found in the coding sequence of the R-PK gene in five patients with severe hemolytic anemia due to PK deficiency are described. The enzyme variants were designated PK Mosul (homozygote), PK Bukarest_1,2, PK Hamburg₁, PK Köln₁, and PK Essen (compound heterozygote). PK Mosul showed normal positive cooperative substrate binding, PK Bukarest_1,2 exhibited noncooperative behavior, and PK Hamburg₁ and PK Köln₁ displayed mixed cooperativity, whereas PK Essen was negative cooperative. PK Mosul was found to be homozygous for the mutation 1151 ACG to ATG, resulting in an amino acid substitution 384 Thr to Met. In one allele of PK Bukarest_1,2 a single nucleotide substitution GAG-TAG was found at nucleotide 721, causing a change of 241 Glu to a chain termination codon (PK Bukarest₁). Additionally, in the second allele of this patient a point mutation at position 1594 (CGG-TGG) occurs, changing 532 Arg to Trp (PK Bukarest₂). Direct sequencing showed the heterozygosity of the patient's mother (PK Bukarest₁/normal) at position 721 and of the patient's father (PK Bukarest₂ /normal) at position 1594. A point mutation at position 1529 (CGA-CAA), causing an amino acid substitution 510 Arg-Gln, was identified in PK Hamburg₁ and PK Köln₁. The second mutation in these variants was not detected. In PK Essen no mutation in the coding sequence was found at all. Screening for the mutation at position 1529 in further compound heterozygote patients and in normal subjects of Western European origin showed that this exchange is a common mutation responsible for PK deficiency in this population.Supported by theDeutsche Forschungsgemeinschaft, Grants no. La 527/1 and Ne 416/1.     

The ability of heat stress and metabolic preconditioning to protect primary rat cardiac myocytes

Primary rat cardiocytes were subjected to either thermal preconditioning for 30 min at 43°C or 20 min metabolic preconditioning (10 mM deoxyglucose, 20 mM lactate, pH 6.5). Eighteen hours later cells were analysed either for hsp 70i expression or subjected to a subsequent lethal heat stress or simulated ischaemia (10 mM deoxyglucose, 20 mM lactate, 0.75 mM sodium dithionite, 12 mM potassium chloride, pH 6.5) for 2 hours and assessed for survival by trypan blue exclusion.Hsp 70i was induced over 100 fold by thermal preconditioning and 30 fold by metabolic preconditioning (p<0.001, p<0.05), hsp 90 was induced 2.71 fold and 2.24 fold (p<0.001, p<0.001) by thermal and metabolic preconditioning respectively, while hsp 60 was not induced by either treatment. Preconditioned cultures had improved survival against subsequent lethal heat stress or simulated ischaemia: Thermal preconditioning reduced death from 69.22% to 52.46% upon subsequent lethal heat stress and from 49.13% to 36.66% upon subsequent lethal simulated ischaemia. Metabolic preconditioning reduced cell death from 51.29% to 33.8% against subsequent lethal heat stress, and from 69.09% to 55.61% upon subsequent lethal simulated ischaemia. A second marker of cell death, the release of lactate dehydrogenase activity into the culture media, was reduced to 65% and 60% of control values for thermally preconditioned cells subjected to lethal heat or lethal simulated ischaemia respectively. Metabolically preconditioned cells demonstrated lactate dehydrogenase activity of 59% and 51% that of control values, when subjected to lethal heat or lethal simulated ischaemia respectively.Abbreviations hsp heat stress protein - hsp 70i inducible 70 kDa heat stress protein - LDH lactate dehydrogenase - PBS phosphate buffered saline     

Attempted treatment of fulminant viral hepatitis with human fibroblast interferon

Summary -interferon was administered by intravenous infusion to 16 patients affected with fulminant hepatitis B virus infection in third or fourth-grade coma. Ten patients presented a superinfection or a co-infection due to the delta ()-agent. None had detectable interferon (IFN) activity before therapy was begun. Besides fever, no significant side-effects were observed during treatment. Both the IFN-treated group as well as the historical control group, made up of 70 cases of fulminant virus hepatitis, not treated with IFN and observed during a previous ten year-period, received supportive therapy; survival rates were similar in both groups. Furthermore, the presence or absence of the -agent did not appear to affect survival rates significantly.

---

Zusammenfassung -Interferon wurde 16 Patienten i.v. infundiert, die an einem Leberkoma dritten oder vierten Grades infolge fulminanter Hepatitis-B-Virus-Infektion litten. Zehn von ihnen wiesen eine durch -Agens bedingte Super- oder Koinfektion auf. Bei keinem Patienten konnte eine meßbare Interferon (IFN)-Aktivität vor Therapie-Beginn nachgewiesen werden. Außer Fieber wurden während der Behandlung keine nennenswerten Nebenwirkungen beobachtet. Die Überlebensraten waren nahezu gleich bei den mit Interferon behandelten Patienten und bei einer aus 70 Fällen von fulminanter Virus-B-Hepatitis gebildeten historischen Kontrollgruppe, welche in den vorherigen zehn Jahren lediglich mit unterstützenden Maßnahmen behandelt worden war. Außerdem konnten keine statistisch signifikanten Unterschiede in der Überlebenstrate -positiver und -negativer Patienten festgestellt werden.

     

The establishment of a polyposis register

Guidelines are presented for the establishment of a regional or national register of patients with familial adenomatous polyposis. The detailed recommendations are based on the work in committees of the Leeds Castle Polyposis Group and the EuroFAP. The aims of national and regional polyposis registers are discussed, and the stages of development of a register are reviewed: Ascertainment of probands, construction of pedigrees, identification of family members at risk, and screening of members at risk. The problem of data confidentiality is discussed.

---

Résumé Les consignes sont présentées pour l'établissement d'un registre Régional ou National des patients avec polypose adénomateuse familiale. Les recommandations détaillées sont basées sur les travaux des comités du Leeds Castle Polyposis Group et de EuroFAP. Les buts des registres Régionaux ou Nationaux des polyposes sont discutés et les stades de développement du registre sont passés en revu: l'assurance de probande, la construction de l'arbre généalogique, l'identification des familles des membres à risques et l'étude des membres à risques. Le problème de la confidentialité des faits est discuté.

---

---

This paper is based on a report from committees of the Leeds Castle Polyposis Group and the EuroFAP.     

Regional depletion of adenosine triphosphate,phosphocreatine, and glucose in ischemic hippocampus

The selective vulnerability of pyramidal neurons in the CA1 hippocampal region in ischemic rat brain may be preceded by regional alterations of energy metabolism during early reperfusion. We measured ATP, phosphocreatine (PCr), and glucose in paramedian and lateral CA1 and in an area showing little postischemic cell loss, CA2. ATP levels in paramedian CA1 were depressed immediately after 30 min of ischemia (P 0.02) and remained abnormal after 2 hr of reperfusion (P 0.05). PCr was reduced substantially in both subdivisions of CA1 immediately after ischemia (P 0.04) but returned to normal levels after 2 hr. Glucose levels were depressed in paramedian CA1 and CA2 after ischemia (P 0.02) but corrected with reperfusion. We determined P, the sum of ATP and PCr, in separate experiments investigating regional differences in consumption of high-energy phosphate metabolites during complete ischemia. The P levels of rats subjected to 30 min of reversible ischemia followed by 2 hr of reperfusion showed a different pattern of regional differences from those seen in sham-ischemic animals (P 0.01), indicating a persistent depression of metabolic rate in CA1 during reperfusion. We conclude that regional depletion of high-energy phosphates and alteration of metabolic rate may contribute to the selective vulnerability of the CA1 region during brain ischemia.     

Morphometric evaluation of the hypothalamic-ovarian axis of the ketonuric,diabetic Chinese hamster: Relationship to the reproductive cycle

Summary The relationship between diabetes and the morphological alterations which occur in hypothalamic and ovarian tissue was examined in the long-term, ketonuric-diabetic Chinese hamster. Matched diabetic and non-diabetic control hamsters were inspected daily for changes in the reproductive cycle by vaginal lavage. On dioestrus, animals were perfused, the hypothalamus and ovaries collected, prepared for microscopy and morphometrically analyzed. The nuclei in the medial basal hypothalamus of diabetic hamsters exhibited a decreased area (p<0.01) and neuronal population (p<0.05–0.01) compared with controls. The ovaries of the diabetic animals had a reduced follicular population (p0.05) and an increased atresia rate (p0.05) compared with controls. In addition, all diabetic hamsters were acyclic. In diabetic animals, the corpora luteal cells contained a reduced lipid content (p0.001) which was possibly functionally related to a significant decline in serum progesterone levels (p0.01). Based on these results it is suggested that the hypothalamic-ovarian axis is both morphologically and functionally impaired in the diabetic hamster.     

Calcium channel blocker treatment of tumor cells induces alterations in the cytoskeleton,mobility of the integrin αIIbβ3 and tumor-cell-induced platelet aggregation

Summary Calcium channel blockers of the phenylalkylamine (i.e. verapamil), benzothiazepine (i.e. diltiazem) and dihydropyridine (i.e. nifedipine) classes were evaluated for effects on the tumor cell/platelet interactions using Walker 256 carcinosarcoma cells (W256 cells). When W256 cells were pretreated for 15 min with channel blockers at concentrations of 50–200 M, macroscopic tumor-cell-induced platelet aggregation was inhibited (order of potency; nifedipine>diltiazemverapamil). However, ultrastructural analysis revealed limited, focal platelet aggregates associated with tumor cell plasma membranes of verapamil- and diltiazem-treated cells. There was no evidence of platelet activation or platelet association with the tumor cell membrane in cells pretreated with nifedipine. Walker 256 cells possess the integrin _IIb3. Tumor cell _IIb3 was shown to mediate tumor cell/platelet interactions in vitro [Chopra et al. (1988) Cancer Res. 48:3787]. Patching and capping of surface _IIb3 were inhibited by nifedipine>diltiazemverapamil. The degree of inhibition of _IIb3 receptor mobility parallels the inhibition of tumor-cell-induced platelet aggregation. W256 cells are characterized by a well-developed microfilament and intermediate filament network and by the absence of a distinct microtubular network. Calcium channel blockers had no effect on the low polymerization level of tubulin. However, they induced rearrangement of microfilament stress fibers. Intermediate filaments were also rearranged but to varying degrees. The order of effectiveness for alteration of intermediate filament organization was nifedipine>diltiazem while verapamil was ineffective. We propose that the previously reported inhibition of tumor cell/platelet interaction and tumor cell metastasis by calcium channel blockers [Honn et al. (1984) Clin Exp Metastasis 1:61] is due not only to the effects of the Ca²⁺ channel blockers on platelets, but also to their effect on the tumor cell cytoskeleton resulting in an inhibition of the mobility and function of the _IIb3 receptor.Abbreviations CCB calcium channel blocker - _IIb3 platelet glycoprotein IIb/IIIa complex - TCIPA tumor cell induced platelet aggregation - W256 Walker 256 carcinosarcoma This work was supported by Public Health Service grant CA-47115, a grant from Harper Hospital and a grant from the Veterans Administration     

Survival of two patients with severe δ-aminolaevulinic acid dehydratase deficiency porphyria

The course of -aminolaevulinic acid dehydratase activity was studied over the 23 years in erythrocytes of two male patients. The enzyme activity was originally 1–2%, which then increased to 8% of normal levels several years after clinical manifestation of the acute hepatic porphyria syndrome. Urinary excretions of -aminolaevulinic acid and coproporphyrin III were excessively increased in the two patients with compound-heterozygous -aminolaevulinic acid dehydratase deficiency porphyria.     

Changes in the activity of ‘active’ pyruvate dehydrogenase complex in the newborn of normal and diabetic rats

Summary At birth, hepatic active and dichloracetate-activated pyruvate dehydrogenase complex activities in the newborn of normal, mildly diabetic, and severely diabetic rats were similar. The active and dichloracetate-activated pyruvate dehydrogenase complex activities increased significantly during the first 2 and 6 postnatal h, respectively in the three groups of neonates (p<0.05). The greatest increase in both active and dichloroacetate-activated pyruvate dehydrogenase complex activity was observed in the neonates of mildly diabetic rats. Administration of glucose or insulin at birth to the newborn of normal rats caused a significant increase in the percentage of active pyruvate dehydrogenase complex activity within 1 h (p<0.01). Similar treatment caused no significant increases in the newborn of severely diabetic rats. The transient increases in active pyruvate dehydrogenase complex activity in the neonates of normal and diabetic rats were consistent with rapid disappearance of blood lactate during the first hours of postnatal life.     

Glutathione synthetase deficiency: is gamma-glutamylcysteine accumulation a way to cope with oxidative stress in cells with insufficient levels of glutathione?

Glutathione (GSH) plays a major role in the cellular defence against oxidative stress and other vital cellular functions. It therefore seems inevitable that patients with severe depletion of GSH will not survive. However, at least some with glutathione synthetase (GS) deficiency do. This study was done to determine whether these patients have a mechanism to compensate for their GSH deficiency. Cell-free extracts of cultured fibroblasts from 9 patients with GS deficiency and 9 control subjects were analysed by HPLC for low-molecular-weight thiol compounds. The patients cells contained 7.4nmol of GSH per mg of protein (median; range 2.8–25.2) compared to 33.0nmol in control fibroblasts (range 26.7–51.4) (p<0.01). On the other hand, the patients cells accumulated 18.1nmol of -glutamylcysteine (-GC) per mg of protein (median; range 6.9–71.7), whereas the control cells contained 0.1nmol (range 0.05–0.16) (p<0.01). The cysteine concentrations in the patients cells were 20.7nmol/mg protein (median; range 9.4–52.9) compared to 8.9nmol in control cells (range 3.0–12.4) (p<0.01). Cultured fibroblasts from patients with GS deficiency have low levels of GSH, but instead accumulate -GC. We suggest that -GC, which contains both reactive groups of GSH (i.e. the sulphydryl and -glutamyl groups), can compensate for GSH in the cellular defence against oxidative stress. Thus, -GC may alleviate, but only partly prevent, serious consequences of insufficient GSH levels in affected patients. Since the sum of the levels of GSH and -GC in GS-deficient cells (median 31.5nmol/mg protein, range 16.2–79.0) was similar to the level of GSH alone incontrol cells (33.0nmol/mg protein, range 26.7–51.4), we propose that the cultured fibroblasts may have a mechanism to regulate in a coordinated way the levels of GSH and -GC; for instance, by both compounds acting as feedback inhibitors of -GC synthetase.     

Calcium-antagonists and islet function. IV. effect of D600

Summary D600 (2 to 20 M;-isopropyl- [(N-methyl-N-homoveratril)--aminopropyl]-3,4,5 -trimethoxyphenyl-acetonitril) caused a dose-related, rapid and reversible inhibition of glucose-induced insulin release. It also suppressed the insulinotropic action of a sulphonylurea but failed to affect the enhancing action of theophylline upon glucose-induced release. The inhibitory effect of D600 was enhanced at low extracellular Ca²⁺ concentration. D600 reduced both basal and glucose-stimulated⁴⁵calcium net uptake, whilst failing to affect the efflux of⁴⁵calcium from perifused islets. The recognition of glucose by the B-cell was also unaffected by D600 as judged by the effect of the sugar upon both 45 calcium efflux and net uptake in the isolated islets. These findings are compatible with the hypothesis that the primary mode of action of D600 is to inhibit Ca²⁺entry in the B-cell.(-isopropyl- [(N-methyl-N-homoveratril)--aminopropyl]-3, 4, 5-trimethoxyphenyl-acetonitril)     

Lack of α2-Antiplasmin Enhances ADP Induced Platelet Micro-Aggregation through the Presence of Excess Active Plasmin in Mice

Background: The role of 2-antiplasmin (2-AP) on platelet aggregation was investigated using mice deficient in 2-AP (2-AP^–/–) or using wild type mice (2-AP^+/+). Methods: Blood samples were taken from each mouse under anesthesia with ether and platelet rich plasma (PRP) was prepared. Platelet aggregation induced by various doses of ADP (0.3–30 M) was detected using a laser-light scattering (LS) system. Aggregated forms were observed using a scanning electron microscopy (SEM). Results: Dose-dependent platelet aggregation was not different in both types of mice. However, platelet micro-aggregate formation in 2-AP^–/– mice induced by low dose of ADP (1.0 M) markedly increased compared to the situation in wild type mice. Aggregated form detected by SEM showed supported data from LS analysis. When washed platelets of 2-AP^+/+ mice were resuspended in plasma of 2-AP^–/– mice, platelet micro-aggregation was also increased. On the contrary, when washed platelets of 2-AP^–/– mice were suspended in plasma of 2-AP^+/+ mice, platelet micro-aggregation did not change. In separate experiments, tPA (1.0 g/ml) was added to PRP before the stimulation of ADP. tPA had no effect on platelet aggregation in 2-AP^+/+ mice, however platelet micro-aggregation in 2-AP^–/– mice was markedly increased by the treatment with tPA. Moreover, the amount of released ATP from stimulated platelets was increased in 2-AP^–/– mice treated with tPA. Conclusion: Lack of 2-AP increased platelet micro-aggregation, and plasmin plays an important role in the formation of platelet aggregation when 2-AP knockout mice are used. Consequently, the reduction of 2-AP could be a risk factor for the activation of platelets resulting in thrombus formation.     

Enzymatic determination of serum 3α-sulfated bile acids concentration with bile acid 3α-sulfate sulfohydrolase

A newly developed enzymatic method for determining urinary 3-sulfated bile acids was used to measure serum 3-sulfated bile acid levels in 114 patients with hepatobiliary diseases and 56 healthy subjects. The lowest measurable amount of the 3-sulfated bile acids was 0.5 µmol/liter. The standard curves for glycolithocholic acid 3-sulfate, glycoursodeoxycholic acid 3-sulfate, and lithocholic acid 3-sulfate were linear from 0.5 to 250 µmol/liter. Specificity of the assay was satisfactory and intra- and interassay variations ranged from 0.8 to 4.4% and from 1.2 to 7.9%, respectively. Analytical recovery was more than 91%. The values obtained by this assay were well correlated with those by gas-liquid chromatography measurement (r=0.91,P<0.01). The fasting serum 3-sulfated bile acids level in healthy subjects ranged from undetectable to 1.9 µmol/liter (mean±se; 0.9±0.1 µmol/liter). The percentage of 3-sulfated bile acids in total bile acids (sum of 3-sulfated and 3-hydroxy bile acids) in serum was 16.8±1.5%. In subjects with hepatobiliary diseases, serum 3-sulfated bile acids levels were elevated; however, the percentage of 3-sulfated bile acids in total bile acids was decreased and correlated with the severity of hepatocellular insufficiency. This enzymatic assay is simple, rapid, and accurate for the determination of serum 3-sulfated bile acids.     

Appearance of a functional insulin receptor during rabbit embryogenesis

Summary The domain structure of the insulin receptor was investigated in liver and brown adipose tissue of developing rabbits. The structure of the binding domain (-subunit) was analysed after covalent labelling with a ¹²⁵I photo-reactive insulin analogue. The structure of the tyrosine kinase domain (-subunit) and the transmission of the hormonal signal from the -to the -subunit were analysed by stimulating with insulin the autophosphorylation of the -subunit. Finally, the immunoreactivity of the receptor in developing tissues was assessed with anti-receptor antibodies. The results show that a functional insulin receptor can be detected at the early stages of fetal development in both tissues and is conserved throughout ontogenesis to adulthood.     

Niemann–Pick disease type C and defective peroxisomal β-oxidation of branched-chain substrates

An 18-month-old infant presented with hypotonia, motor delay, hepatosplenomegaly, rickets and steatorrhoea. Biochemical investigations revealed typical features of Niemann–Pick disease type C. In addition, there was evidence of defective peroxisomal -oxidation of branched-chain substrates (3,7,12-trihydroxycholestanoic acid and pristanic acid). The steatorrhoea and fat-soluble vitamin malabsorption responded well to bile acid therapy. Possible causes for the double defect are considered.     

Serum zinc and copper in active rheumatoid arthritis: Correlation with interleukin 1β and tumour necrosis factor α

Serum zinc and copper levels and serum interleukin 1 (IL1) and tumour necrosis factor (TNF) levels were evaluated in 57 female patients with active rheumatoid arthritis (RA) to investigate a possible role of IL1 and TNF on zinc and copper homeostasis in RA. Serum zinc levels were significantly lower and serum copper levels significantly higher in RA patients when compared with osteoarthritis or asymmetrical psoriatic oligoarthritis patients and with normal controls. No differences were observed in serum IgM rheumatoid factor positive and serum IgM rheumatoid factor negative patients as regards serum zinc and copper concentration. In RA patients the erythrocyte sedimentation rate and acute-phase proteins correlated negatively with serum zinc and positively with serum copper. IL1 and TNF were found to correlate negatively with zinc and positively with copper in RA patients. Lower levels of zinc may be due to an accumulation of zinc-containing proteins in the liver and in the inflamed joints in RA. Elevated serum copper levels seem to be linked to the increased synthesis of ceruloplasmin by the liver.