A regulatory link between ER-associated protein degradation and the unfolded-protein response.

Ubiquitin conjugation during endoplasmic-reticulum-associated degradation (ERAD) depends on the activity of Ubc7. Here we show that Ubc1 acts as a further ubiquitin-conjugating enzyme in this pathway. Absence of both enzymes results in marked stabilization of an ERAD substrate and induction of the unfolded-protein response (UPR). Furthermore, basic ERAD activity is sufficient to eliminate unfolded proteins under normal conditions. However, when stress is applied, the UPR is required to increase ERAD activity. We thus demonstrate, for the first time, a regulatory loop between ERAD and the UPR, which is essential for normal growth of yeast cells.

Import of mitochondrial carriers mediated by essential proteins of the intermembrane space.

In order to reach the inner membrane of the mitochondrion, multispanning carrier proteins must cross the aqueous intermembrane space. Two essential proteins of that space, Tim10p and Tim12p, were shown to mediate import of multispanning carriers into the inner membrane. Both proteins formed a complex with the inner membrane protein Tim22p. Tim10p readily dissociated from the complex and was required to transport carrier precursors across the outer membrane; Tim12p was firmly bound to Tim22p and mediated the insertion of carriers into the inner membrane. Neither protein was required for protein import into the other mitochondrial compartments. Both proteins may function as intermembrane space chaperones for the highly insoluble carrier proteins.

Estimation of reference intervals from a SENIEUR protocol compatible aged population for immunogerontological studies.

Because many laboratory values change with age, the study of healthy aging as well as diagnosis of disease in geriatric patients requires specific age-corrected reference intervals. We have established such reference intervals for a healthy population aged 65-74 years by selection of a sample group applying the clinical criteria of the SENIEUR protocol and we have compared them with those of a young control group (20-33 years) fulfilling the same criteria. Significant or minor elevations were seen, e.g. for plasma concentrations of fasting glucose, urea, total and LDL-cholesterol, triglycerides, gamma-glutamyl-transferase, alkaline phosphatase, erythrocyte sedimentation rate and serum neopterin levels. These reference intervals can be used for selecting a SENIEUR compatible population aged between 65 and 74 years. Additionally, plasma lipid parameters (cholesterol, triglycerides) are proposed to be included in the SENIEUR protocol.

Properties of low density lipoproteins relevant to oxidative modifications change paradoxically during aging.

Atherosclerosis is a common problem among the elderly. Because lipid peroxidation is considered a contributor to the development of atherosclerosis, we compared oxidative properties of lipoproteins in an otherwise healthy (SENIEUR-classified) aged population (65-74 years) with young controls (18-30 years). Relative amounts of oxidatively altered low density lipoprotein (LDL), estimated by means of an antibody against LDL modified by 4-hydroxynonenal, a product of lipid peroxidation, were increased marginally in serum from the elderly (9.8 vs. 7.4%, P = 0.07). In contrast, isolated LDL from the elderly revealed a decreased susceptibility to in vitro oxidation: the lag time was increased (2.34 vs. 2.10 h, P < 0.01), and the maximal rate of LDL oxidation decreased (0.88 vs. 1.01 O.D./h, P = 0.001). However, there were no age-related changes in lipid composition of native LDL and consumption of fatty acids during in vitro oxidation. The serum concentrations of ascorbic acid and most lipophilic anti-oxidants (the latter expressed per g serum lipids) were significantly decreased in the elderly except tocopherols which tended to be higher. In conclusion, our data reveal paradox age-related alterations of LDL as to its behaviour in oxidation in vivo vs. in vitro.

Increased concentrations of neopterin in carotid atherosclerosis.

Activation of T-cells and macrophages may play a role in the pathogenesis of atherosclerosis. Therefore, serum concentrations of the immune activation markers neopterin and soluble interleukin-2 receptor were compared with routine laboratory parameters, candidate risk variables and degree of carotid atherosclerosis. Study subjects were 561 individuals (293 men and 268 women) aged between 50 and 79 years who were enrolled in a cross-sectional community based study (Ischemic Heart Disease and Stroke Prevention Study, Bruneck, Italy). Extent of carotid atherosclerosis was quantitated by an ultrasound B-mode procedure based scoring system. Detailed physical examination and quantification of laboratory and candidate risk variables were performed. By univariate as well as multivariate statistical analyses, serum concentrations of neopterin but not soluble interleukin-2 receptor were significantly higher in subjects with carotid atherosclerosis (men, 8.5 +/- 2.7 nmol/l neopterin; women, 9.6 +/- 3.3) than in those without (men, 6.7 +/- 2.3, P < 0.0001; women, 7.5 +/- 2.3, P < 0.0001). The data show that the macrophage-derived immune activation marker neopterin is closely correlated with the extent of carotid atherosclerosis. Chronic activation of immune cells, preferentially of macrophages, may play a key role in atherogenesis and/or progression of atherosclerosis.

Diatomaceous earth lowers blood cholesterol concentrations.

In this study a potential influence of diatomaceus earth to lower blood cholesterol was investigated. During 12 weeks we monitored serum lipid concentrations in 19 healthy individuals with a history of moderate hypercholesterinemia (9 females, 10 males, aged 35 - 67 years). Individuals administered orally 250 mg diatomaceous earth three-times daily during an 8 weeks observation period. Serum concentrations of cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides levels were measured before study entry, every second week during the period of diatomaceous earth intake and 4 weeks after stop of intake. Compared to baseline (285.8 +/- 37.5 mg/dl = 7.40 +/- 0.97 mM) diatomaceous earth intake was associated with a significant reduction of serum cholesterol at any time point, reaching a minimum on week 6 (248.1 mg/dl = 6.43 mM, -13.2% from baseline; p<0.001). Also low-density lipoprotein cholesterol (week 4: p<0.05) and triglycerides levels decreased (week 2: p<0.05, week 4: p<0.01). Four weeks after intake of diatomaceous earth was stopped, serum cholesterol, low-density lipoprotein cholesterol and triglycerides still remained low and also the increase of high-density lipoprotein cholesterol became significant (p<0.05). Diatomaceous earth, a bioproduct, is capable of reducing blood cholesterol and positively influencing lipid metabolism in humans. Placebo-controlled studies will be necessary to confirm our findings.

Effect of Vaporub and petrolatum on frequency and amplitude of breathing in children with acute bronchitis.

Transthoracic impedance pneumographs from sixty children suffering from acute bronchitis were studied to investigate the effect of Vaporub on the amplitude and frequency of breathing. The experimental technique consisted of an observation period of 70 minutes after a 3-minute treatment with Vaporub or petrolatum as a control. Before the treatment, after an adaptation period of 20 minutes, the pneumogram was recorded for 10 minutes, after the treatment pneumograms were recorded for 70 minutes. The pneumograph data demonstrated an early increase in amplitude up to 33.0%, with subsequent return to slightly above control for the remaining test period. Such an increase was not observed in the Petrolatum-treated group. Breathing frequency demonstrated a progressive decrease to 19.4% of the pre-treatment value at the end of the test period, while the Petrolatum controls were between + 3.6 to - 4.2% difference. It is concluded that Vaporub treatment results in a change in breathing patterns. This, together with the clinical observation of the children suggests a condition of 'easier breathing'.

Effect of Vaporub on the restlessness of children with acute bronchitis.

In this study pneumographs of children with acute bronchitis treated with Vicks Vaporub or Petrolatum were used. Movement artifacts were used as a measure of the so-called "restlessness" of the children. The experimental schedule consisted of a 10-minute phase of recording before a 3-minute treatment with Vaporub or Petrolatum, followed by a 70-minute observation period, during which time pneumograms were also recorded. Thirty-four Vaporub-treated children showed an increase in periods without movement artifacts of up to 213.8%, the Petrolatum controls, twenty-six children, up to 62.4% as compared to the corresponding pre-treatment values. It is concluded that Vaporub is effective in decreasing restlessness in children suffering from acute bronchitis. This effect is quite marked and cannot be due solely to psychological effects of the rub therapy, or to effects of petrolatum without aromatics.

Effect of Vaporub and petrolatum on skin and rectal temperature in children with acute bronchitis.

Fifty-six children, suffering from acute bronchitis were studied. Skin temperature and rectal temperature were simultaneously recorded over a period of 90 minutes after 3-minute rub therapy on chest and back with either Vaporub or its base Petrolatum. A statistically significant increase in skin temperature as compared to the pre-treatment was observed; with Vaporub, however, the increase was 1.1 degrees C on average at the highest point of a large plateau reaching from 30 to 90 minutes after the treatment. Rubbing Petrolatum alone showed 0.2 degrees C on average on the top of the temperature plateau. Rectal temperature did not show significant changes with either therapy. On comparing temperature data of the same type in healthy children, the time course of the temperature elevation (which also was observed in healthy children after Vaporub treatment), was different from that of bronchitic children. In the bronchitic children the temperature rise was still 0.9 degrees C 60 minutes after treatment. In the healthy children after 60 minutes, the temperature elevation was only 0.4 degrees C above the pre-treatment value.

[Reversible suppression of synaptic function by anti-synaptosome-antibodies (author's transl)]. / Reversible Blockierung von Synapsenfunktionen mittels Antikörper gegen Synaptosomenmembranen.

We report about experiments to isolate Synaptosome-Membranes of the rat cerebellum in order to produce Antibodies directed toward these membranes in rabbits. The raised Antisera were tested in different Complement-fixation-assays. They reacted only with the Synaptosome-Membranes, not with heart, kidney, liver- and spleen-membranes. Different fractions of the isolation-procedure for synatosomal membranes were also checked for their ability to fix Complement. Only Synaptosomes and the synaptosomal membranes gave sufficient Complement fixation, while Mitochondria, soluble brain proteins, synaptic vesicles and braincell nuclei did not. These biochemical and immunological findings are further supported by electrophysiological data, where the transsynaptic component of the parallel fibre-evoked field potential was strongly suppressed by the administration of the immune sera containing antibodies against membranes of synaptosome fractions.

Glutamine: a new anticystinuric drug?

A recent report by Miyagi and co-workers [New Engl. J. Med. 301: 196-198, 1979] suggested that glutamine caused a decrease in cystine excretion in 1 patient. We studied 2 patients with cystinuria on 2-4 g glutamine for 24 and 60 days. In these patients glutamine showed no effect on the excretion of cystine in the urine. This is consistent with the report by the Mayo clinic where 5 patients were treated with glutamine without any response.

[Congenital hyperlysin-arginin-ornithinuria in a mentally retarded child (author's transl)]. / Kongenitale, isolierte Hyperlysin-Arginin-Ornithinurie bei einem cerebral retardierten Kind.

Congenital hyperdibasicaminoaciduria without cystinuria was detected in a mentally but not physically retarded boy. Plasma lysine and arginine were normal, whereas plasma ornithine was decreased. Although oral or intravenous loading tests could not be performed, the history without vomiting or diarrhea, and the normal physical development indicated an unimpaired intestinal transport of basic aminoacids. Our case could be a further mutant of this transport defect which concerns the renal tubuli only.

[Angiotensin I biosynthesis and electrolytes]. / Angiotensin-I-Bildung und Elektrolyte.

An influence on the production of Angiotensin-I by different ions is demonstrated. Plasma Renin activity was thereby measured by the methods of Boyd et al. (pH 7.5) and of Fyhrquist et al. (pH 6.0) at a concentration of each ion of 50 mmol/L. Ions of different size were used, ranging from Lithium to the Ammonium-ion. A definitive dependency of this effect on the Angiotensin production by the ion size could be shown. With Sodium the concentration in serum was varied at 5 levels (130-170 mmol/L) and Renin measured at Potassium concentrations in low (3.4-3.7 mmol/L) or high (4.8-5.1 mmol/L) so-called normal ranges. A marked increase of the production of Angiotensin-I with increasing sodium concentrations at a low Potassium range was observed and the opposite was true at high Potassium concentrations. These effects have to be taken into account when assaying Plasma Renin activity. In addition, they offer also an explanation of the well-known but unsolved facts of the influence of Sodium and Potassium on the pathogenesis of hypertonia.

[Maternal phenylketonuria]. / Maternale Phenylketonurie.

We report about the child of a mother with phenylketonuria, which is not suffering from PKU, but is microcephalic and mentally retarded. This retardation is probably a sequel of an intrauterine Hyper-Phenylalanine-status. It is supposed that an intrauterine damage of the offspring even in cases with low Phenylalanine-levels of the mother is possible.

A new approach to measure restlessness.

A new method to measure restlessness is described. It consists mainly of recording thoracic electrical impedance and measuring the amount of movement artifacts appearing in the pneumographs. Technical equipment and data evaluation are described; an example of typical data is given together with proposals as to how the method may be automated. Potential applications in different fields of interest are described.

[Histidinemia in a normal intelligent boy with hearing defect (author's transl)]. / Histidinämie bei einem normal intelligenten, jedoch hörbehinderten Knaben.

Amino acid screening in an institute for children with hearing defects led to the detection of a 14 years male with histidinuria. Further investigations established the diagnosis histidinemia. In this normal intelligent patient audiologic tests showed bilateral internal ear hearing defect. It is accepted that the hearing defect is the reason for speech abnormities in form of diminished articulation. But it is not clear how far the inborn error of histidine metabolism is directly responsible for the hearing loss. This observation suggests that the well known speech defects in histidinemics are partly caused by hearing disability.

[Usefulness of the serum-xylose-test in comparison with small-intestine morphology in the malabsorption syndrome]. / Uber die Aussagekraft des Serum-Xylose-Tests im Vergleich zur Morphologie der Dünndarmschleimhaut beim Malabsorptionssyndrom.

In 148 children, 4 months to 14 1/2 years old, 192 serum-xylose-tests (XT) and small bowel biopsies have been performed because of suspected intestinal malabsorption. The results of the XT and of the biopsies were compared to investigate the diagnostic value of the XT with respect to the morphology of the small bowel mucosa. Further we wanted to determine at which time after the oral intake of xylose the best correlation of XT and morphology can be expected. In children with normal mucosa the XT differed significantly from those with subtotal mucosal atrophy but not with partial villous atrophy. However, partial villous atrophy could be differentiated from subtotal villous atrophy with the same test. In children with subtotal villous atrophy a statistically significant age-dependency could be observed, comparing children being less or more than 2 years old and also a dependency from periods with gluten-free diet. Partial villous atrophy with or without coeliac disease cannot be differentiated by means of the XT. Best correlation of the XT and the morphology of the small bowel mucosa can be found 60 minutes after the oral xylose load; no additional information is obtained by more blood-xylose-determinations (e.g. 30, 90, 120, 180 minutes). Because of the rather high standard deviation of the individual blood xylose values no exact prediction can be made from the XT to the mucosal morphology. Therefore the XT is only of value for screening purposes and its results should not influence the indication for a small bowel biopsy, derived from clinical considerations.