E-health. Patterns of use and perceived benefits and barriers among people living with HIV and their physicians. Part 2: Health apps and smart devices.

OBJECTIVES: To evaluate patterns of use and perceived benefits and barriers to health/wellness applications (apps) and smart devices among people living with HIV (PLHIV) and their physicians. METHODS: Online multicenter observational survey (October 15-19, 2018). RESULTS: Study participation was accepted by 229 physicians and 838/1377 PLHIV followed in 46 centers, of which 325 (39%) responded online. Overall, 83/288 (29%) PLHIV had already downloaded at least one app: these 'downloaders' were younger (OR0.96±0.01, P=0.004), educated to at least university entry level (OR2.27±0.86, P=0.03), and more frequently used geolocation-based dating websites (OR3.00±1.09, P=0.002). However, 227/314 (72%) PLHIV claimed they were ready to use an app recommended by a physician. For the 60/83 PLHIV who answered, the ideal app would be a vaccination tracker (76%) to better communicate with their physician (68%). However, 96/277 (42%) physicians were unable to answer this question and for 94/227 (41%) of them, the ideal patient app would be for schedule management. Although PLHIV used smart devices, 231/306 (75%) would want to report the data to their physicians and 137/225 (61%) of physicians would welcome this exchange. The main physician-side barrier to this exchange was concerns over data security. CONCLUSION: mHealth apps and smart devices have failed to garner adoption by PLHIV. There is a case for good-quality health data sharing and exchange if PLHIV are provided with appropriately secure tools and physicians are backed up by adapted legislation.

E-health. Patterns of use and perceived benefits and barriers among people living with HIV and their physicians. Part 1: Information retrieval on the Internet and social networks.

OBJECTIVES: To identify patterns of use, perceived benefits, and barriers among people living with HIV (PLHIV) of online searches for health information and via social media. METHODS: Online multicentre observational survey (October 15th-19th, 2018). RESULTS: Study participation was accepted by 838/1377 PLHIV followed in 46 centres, of which 325 (39%) responded online: 181 (56%) had already used the Internet to search for health information; 88/181 (49%) on HIV infection and 78 (43%) on nutrition. These 56% were characterised by a higher educational level (OR=1.82±0.50; P=0.028) and more often consulted other specialists (OR=3.14±1.26; P=0.004). A subset of 87/180 (48%) PLHIV had changed the way they looked after their health based on their online research, and were more often in material/social deprivation (P=0.02) and diabetic (P=0.02). A small subset of 19/180 (11%) had already asked or answered a question on a forum; these people tended to be women (P=0.03) in material/social deprivation (P=0.009). 296/322 (92%) PLHIV trusted their physician whereas only 206 (64%) trusted information sourced on medical websites. 238/323 (74%) PLHIV expected their physicians to recommend websites if asked, whereas only 23/323 (7%) had actually been given this guidance. CONCLUSION: More than half of PLHIV surveyed had already searched for health information on the Internet, and one in two had changed their behaviour based on the online search. PLHIV did not see the Internet as an alternative to physicians but they wanted their physicians to guide them on how to find quality health information to better self-manage their condition.

E-health. Patterns of use and perceived benefits and barriers among people living with HIV (PLHIV) and their physicians - Part 3: Telemedicine and collection of computerized personal information.

OBJECTIVES: To evaluate the patterns of use and perceived benefits and barriers among people living with HIV and their physicians concerning telemedicine and the collection of computerized personal information. METHODS: Multicenter online observational survey from October 15 to 19, 2018. RESULTS: Study participation was accepted by 229 physicians and 838/1,377 PLHIV followed in 46 centers, of which 325 (39%) responded online. We found that while 226/302 (75%) PLHIV accept online prescription renewals and 197/302 (65%) accept online medical certificates, 182/302 (60%) PLHIV-who were more often in material/social deprivation (OR=1.70±0.45; P=0.045), less often born in Île-de-France (OR=0.43±0.15; P=0.018), with lower CD4 T-cell counts (OR=0.999±0.0004; P=0.038), and less often on psychiatric treatment (OR=0.50±0.18; P=0.047)-were receptive to teleconsultations. However, 137/225 (61%) physicians would be uncomfortable teleconsulting due to inadequate data security without it reducing the number of consultations or offering economic benefit. Asked about collection of computerized personal information, 197/296 (67%) PLHIV and 139/223 (62%) physicians agreed it improved quality of care, but 144 (49%) PLHIV and 94/222 (42%) physicians thought it was not sufficiently framed by the law. eHealth was seen as improving coordination between health professionals by 240/296 (81%) PLHIV and seen as a good thing by 181/225 (81%) physicians. CONCLUSION: More than half of PLHIV were ready for telemedicine. PLHIV and physicians endorsed the advantage of e-health in terms of better coordination across health professionals but mistrust the data collection factor, which warrants either clarification or stronger legal protections.

Effects of zinc supplementation on antioxidant enzyme activities in healthy old subjects.

A large body of experimental research indicates that oxidative stress contributes to the processes related to aging and age-related diseases. Trace elements, particularly zinc (Zn), are essential components of the endogenous enzymatic antioxidant defenses. The aim of this study was to determine the activity of three main antioxidant enzymes in plasma [i.e. superoxide dismutase (pSOD), catalase (CAT), glutathione peroxidase (GPx)] and of SOD in erythrocyte (eSOD) in a group of 1108 healthy elderly subjects from different European countries. The same enzymatic activities were evaluated in a subgroup of 108 subjects before and after Zn supplementation. We observed that eSOD activity increased with age, whereas plasma Zn decreased. Moreover, we found that women showed higher eSOD activity and lower plasma Zn compared to men. There were no age and gender-related differences in the activities of pSOD, CAT and GPx. After Zn supplementation, the activities of Zn-dependent enzymes (pSOD and eSOD), as well as plasma Zn concentration, were significantly higher than before supplementation. These results were not influenced by age, gender, plasma Zn variations (Delta Zn) and geographic area. These data suggest the potential beneficial effects of Zn supplementation on Zn-dependent antioxidant enzymes in healthy elderly subjects.

Antioxidant enzyme activities in healthy old subjects: influence of age, gender and zinc status: results from the Zincage Project.

Enzymatic activities of plasma superoxide dismutase (pSOD), catalase (CAT) and glutathione peroxidase (GPx) and erythrocyte superoxide dismutase (eSOD) were assayed in 981 healthy community dwelling old subjects participating in the Zincage Project. The relationship between antioxidant enzyme activities and, respectively, gender, age and zinc status were assessed. eSOD activity was higher in nonagenarians than in 80 year old subjects. Plasma Zn was lower in nonagenarians compared with younger subjects. The prevalence of Zn deficiency increased with age, with normal Zn levels observed in about 80% of adult subjects and only in 37% of the nonagenarians. Women showed higher eSOD and CAT activities compared to men, whereas plasma Zn was higher in men than in women. There was a positive correlation between eSOD activity and age and a negative correlation between eSOD activity and plasma Zn concentrations. An inverse correlation was also found between plasma Zn concentration and age. Further studies on different aspects of Zn metabolism--intake, plasma concentration, peripheral cell concentration, activity and amount of Zn-dependent enzymes--are warranted.

Unitary attention in callosal agenesis.

The interhemispheric organisation of two specific components of attention was investigated in three patients affected by partial or complete agenesis of the corpus callosum. A visuospatial component of attention was explored using a visual search paradigm in which target and distractors were displayed either unilaterally within a single visual hemifield, or bilaterally across both visual hemifields in light of prior work indicating that split-brain patients were twice as fast to scan bilateral displays compared to unilateral displays. A central component of attention was explored using a psychological refractory period (PRP) paradigm in which two visual stimuli were presented laterally at various stimulus onset asynchronies (SOAs), with each stimulus associated with a different speeded two-alternative choice task. The stimulus-response compatibility in the second task was systematically manipulated in this paradigm, in light of prior work indicating that split-brain patients exhibited a close-to-normal PRP effect (i.e., slowing of the second response as SOA is decreased), with, however, abnormally decreasing effects of the manipulation of the response mapping on the second task speed as SOA was decreased. The present results showed that, although generally slower than normals in carrying out the two tasks, the performance of each of the three acallosal patients was formally equivalent to the performance of a matched control group of normal individuals. In the visual search task, the search rate of the acallosal patients was the same for unilateral and bilateral displays. Furthermore, in the PRP task, there was more mutual interference between the lateralised tasks for the acallosal patients than that evidenced in the performance of the matched control group. It is concluded that the visuospatial component and the central component of attention in agenesis of the corpus callosum are interhemispherically integrated systems.

FEC (5-fluorouracil, epidoxorubicin and cyclophosphamide) versus EM (epidoxorubicin and mitomycin-C) with or without lonidamine as first-line treatment for advanced breast cancer. A multicentric randomised study. Final results.

From May 1991 to December 1996, 326 patients with advanced metastatic breast cancer were enrolled in a multicentre, randomised, phase III clinical trial with four arms. Patients were randomised to receive chemotherapy according to the FEC regimen (5-fluorouracil (5-FU) 500 mg/m2, epidoxorubicin (EPI) 75 mg/m2 and cyclophosphamide (CFA) 500 mg/m2, intravenously (i.v.). every 3 weeks) or the EM regimen (EPI 75 mg/m2, i.v. every 3 weeks; mitomycin C (MMC) 10 mg/m2, i.v. every 6 weeks) or the same regimens with the addition of lonidamine (LND) until disease progression (orally, thrice daily, 150+150+300 mg); a maximum of eight chemotherapy cycles were planned. The aim of the trial was 2-fold: to compare the EM regimen with the commonly used FEC regimen and to evaluate the possible role of the addition of LND. Patients were eligible if they had histologically proven breast carcinoma, metastatic or locoregional relapse with measurable and/or evaluable disease and were aged between 18 and 70 years: 318 patients were considered eligible. Patients with previous anthracycline-based adjuvant chemotherapy or those who relapsed within 6 months after any adjuvant chemotherapy regimen were excluded. Chemotherapy-related toxicity of grade > or = 3 was manageable and there was no significant difference between the arms in terms of haematological side-effects. The impact on heart function was mild. No increased toxicity was observed in the LND arms (apart from myalgias in 27-30% of the cases). A significant increase in the complete response rate was observed for the FEC/EM + LND group (20.4%) versus the FEC/EM group (10.8%). The median survival time and the median time to progression for the overall series were 608 days and 273 days, respectively; EM+/-LND achieved significantly improved survival and time to progression versus FEC+/-LND (P=0.01). This result was confirmed also when the analysis was restricted to patients previously treated with adjuvant CMF schedules. On the basis of these results, we conclude that EM may represent a valuable alternative to FEC for patients requiring a first-line regimen for advanced/ metastatic breast carcinoma, especially in patients previously treated with CMF in an adjuvant setting. Furthermore, we conclude that, in spite of a better complete response rate in the LND arms, as there was no clear advantage in time to progression or survival resulting from the addition of LND to the FEC or EM regimens, the routine use of LND is not warranted outside a clinical trial.

Protein-disulfide isomerase (PDI) in FRTL5 cells. pH-dependent thyroglobulin/PDI interactions determine a novel PDI function in the post-endoplasmic reticulum of thyrocytes.

Thyroglobulin (TG) is secreted by the thyrocytes into the follicular lumen of the thyroid. After maturation and hormone formation, TG is endocytosed and delivered to lysosomes. Quality control mechanisms may occur during this bidirectional traffic since 1) several molecular chaperones are cosecreted with TG in vivo, and 2) lysosomal targeting of immature TG is thought to be prevented via the interaction, in acidic conditions, between the Ser(789)-Met(1172) TG hormonogenic domain (BD) and an unidentified membrane receptor. We investigated the secretion and cell surface expression of PDI and other chaperones in the FRTL5 thyroid cell line, and then studied the characteristics of the interaction between TG and PDI. We demonstrated that PDI, but also other chaperones such as calnexin and KDEL-containing proteins are exposed at the cell surface. We observed on living cells or membrane preparations that PDI specifically binds TG in acidic conditions, and that only BD is involved in binding. Surface plasmon resonance analysis of TG/PDI interactions indicated: 1) that PDI bound TG but only in acidic conditions, and that it preferentially recognized immature molecules, and 2) BD is involved in binding even if cysteine-rich modules are deleted. The notion that PDI acts as an "escort" for immature TG in acidic post-endoplasmic reticulum compartments is discussed.

Intracellular degradation of the HIV-1 envelope glycoprotein. Evidence for, and some characteristics of, an endoplasmic reticulum degradation pathway.

Analysis of the fate of HIV-1 envelope protein gp160 (Env) has shown that newly synthesized proteins may be degraded within the biosynthetic pathway and that this degradation may take place in compartments other than the lysosomes. The fate of newly synthesized Env was studied in living BHK-21 cells with the recombinant vaccinia virus expression system. We found that gp160 not only undergoes physiological endoproteolytic cleavage, producing gp120, but is also degraded, producing proteolytic fragments of 120 kDa to 26 kDa in size, as determined by SDS/PAGE in non reducing conditions. Analysis of the 120-kDa proteolytic fragment, and comparison with gp120, showed that it is composed of peptides linked by disulfides bonds and lacks the V3-loop epitope and the C-terminal domain of gp120 (amino acids 506-516). A permeabilized cell system, with impaired transport of labeled Env from the endoplasmic reticulum (ER) to Golgi compartments, was developed to determine the site of degradation and to define some biochemical characteristics of the intracellular degradation process. In the semipermeable BHK-21 cells, there was: (a) no gp120 production (b), a progressive decrease in the amount of newly synthesized gp160 and a concomitant increase in the amount of a 120-kDa proteolytic fragment. This fragment had the same biochemical characteristics as the 120-kDa proteolytic fragment found in living nonpermeabilized cells, and (c) susceptibility of the V3 loop. This degradation process occurred in the ER, as shown by both biochemical and indirect immunofluorescence analysis. Furthermore, there was evidence that changes in redox state are involved in the ER-dependent envelope degradation pathway because adding reducing agents to permeabilized cells caused dose-dependent degradation of the 120-kDa proteolytic fragment and of the remaining gp160 glycoprotein. Thus our results provide direct evidence that regulated degradation of the HIV-1 envelope glycoprotein may take place in the ER of infected cells.

Identification of the membrane receptor binding domain of thyroglobulin. Insights into quality control of thyroglobulin biosynthesis.

The last stages of thyroglobulin maturation occur in the thyroid follicular lumen and include thyroid hormone formation and glycan completion. In this compartment, newly secreted thyroglobulins interact with a thyrocyte membrane receptor that prevents their premature lysosomal transfer and degradation. Both GlcNAc moieties and thyroglobulin peptide determinants are involved in receptor interaction. Here we used monoclonal antibodies (mAbs) directed against human thyroglobulin either to inhibit (mAb78) or to enhance (mAb240) the thyroglobulin binding and to identify the region of the thyroglobulin involved in the receptor recognition. Peptides containing the mAb epitopes were obtained by immunoscreening cyanogen bromide-derived native human thyroglobulin peptides and a cDNA thyroglobulin expression library. Three peptides, localized in the thyroglobulin N-terminal domain, were obtained. Peptides N1 (Ala1148-Gln1295) and N2 (Ser789-Met1008) were recognized by mAb240 and mAb78, respectively. None of them bound the receptor. The third peptide, N3 (Ser789-Met1172), (i) overlapped all or part of the N1 and N2 peptide sequences and was recognized by both mAbs, (ii) carried two complex glycans at Asn797 and Asn928, of which a subset presented accessible GlcNAc residues, and (iii) inhibited the thyroglobulin binding to FRTL5 cell membrane preparations. The N3 peptide includes tyrosine residues that have been reported to be involved in hormone formation. These results suggest that structural modifications closely associated with hormone formation within this domain act as sensors for the receptor interaction and thus for the intrafollicular retention or lysosomal homing of the prohormone.

Carbohydrate and protein determinants are involved in thyroglobulin recognition by FRTL 5 cells.

To avoid premature lysosomal degradation, thyrocytes have a system able to recycle internalized immature thyroglobulin molecules (Tg) to the follicular lumen via the Golgi apparatus. It has been shown that this quality control system depends on recognition of exposed N-acetylglucosamine (GlcNAc) determinants (Miquelis et al., J Cell Biol, 1993, 123, 1695) present on immature Tg (Bastiani et al., 1995, Endocrinology, 1995, 136, 4204). However, the same in vitro kinetics studies also showed that GlcNAc residues alone induce only weak recycling. The latter finding led us to investigate the possibility that protein determinants might also be involved in binding. For this purpose, we studied binding of Tg to FRTL 5 cells, a widely available TSH-dependent cell line and found that binding to plasma membranes occurred at acidic pH in the presence of calcium, i.e. under conditions previously reported for binding of GlcNAc-BSA to porcine thyroid cell membranes. As expected, binding was GlcNAc- and oligosaccharide-dependent because Bandeiraea Simplificiola II affinity column analysis indicated that GlcNAc-bearing Tg were preferentially bound and N-glycanase treatment of Tg inhibited interaction. Ovomucoid, GlcNAc-BSA, and porcine Tg oligosaccharides did not inhibit binding, indicating that carbohydrates were not the sole determinants for binding. The fact that pronase digestion of Tg totally abolished binding implied that peptide determinants were involved in the interaction. This involvement is supported by the observation that porcine, rat, bovine, and human Tg bound FRTL 5 cell membranes and that monoclonal antibodies raised against human Tg interfered with the binding of both human and porcine Tg. Based on these findings we conclude that, besides the involvement of GlcNAc-bearing oligosaccharides, Tg receptors form a stable bond with peptide determinants.

On the relationship between completion of N-acetyllactosamine oligosaccharide units and iodine content of thyroglobulin: a reinvestigation.

Lack of completion of N-acetyllactosamine-type glycosylation on thyroglobulin (Tg) has been implicitly considered as an etiological factor of some thyroid disorders, i.e. goiter and hypothyroidism. However, there is some evidence that Tg with incompletely processed N-acetyllactosamine glycans occurs in the normal gland. Recent findings demonstrated that exposed N-acetylglucosamine (GlcNAc) residues present on internalized glycoprotein in the thyrocyte may act as a retention signal that prevents lysosomal homing and triggers recycling of GlcNAc-bearing molecules through galactosyltransferase- and thyroperoxidase-containing compartments of the Golgi apparatus. This finding raises the possibilities 1) that exposed GlcNAc residues are not randomly distributed, but are mainly present on immature Tg; and 2) that this process promotes elongation of complex glycans, thereby eliminating the retention signal. To further validate this hypothesis, we reinvestigated the relationship between the iodine content and the glycan completion of porcine Tg of luminal origin. Tg subpopulations were separated according to their iodine content on rubidium chloride centrifugation gradients, and their interactions with various plant and animal lectins were analyzed in solid phase assays. Iodine content used as an index of age ranged from 0.6-1.2%. There was no significant correlation between iodine content and either neutral sugar or oligosaccharide content, as judged by chemical methods or interaction with [125I]Solanum tuberosum and [125I]Pisum sativum agglutinins. In contrast, the number of GlcNAc-accessible residues (as judged by interaction with [125I]Bandeiraea simplificolia II) decreased as iodine content increased. These changes were concomitant with an increase in galactose (measured by interaction with [125I]R-icinus communis and [125I]galactosidase (Gal)/GalNAc rat hepatic lectin) and sialic acid content. Related experiments using a Tg subpopulation depleted in GlcNAc-exposed residues by passage through a B. simplificolia II affinity column showed that the capacity of this subpopulation to bind to membranes was lowered compared to that of the total Tg. These results support the following conclusions: 1) in normal glands, all or part of the Tg molecules are secreted in an incompletely glycosylated form; and 2) iodine organification is correlated with glycan completion. Therefore, asialoagalactothyroglobulin appears to be a physiological precursor for an efficient recycling mediated by the GlcNAc receptor to the iodination site. New insights in thyroid disorders are discussed.

Intracellular routing of GLcNAc-bearing molecules in thyrocytes: selective recycling through the Golgi apparatus.

Previous experiments led us to speculate that thyrocytes contain a recycling system for GlcNAc-bearing immature thyroglobulin molecules which prevents these molecules from lysosomal degradation (Miquelis, R., C. Alquier, and M. Monsigny. 1987. J. Biol. Chem. 262:15291-15298). To confirm this hypothesis, the fate of GlcNAc-bearing proteins after internalization by thyrocytes was monitored and compared to that of fluid phase markers. Kinetic internalization studies were performed using 125I-GlcNAc-BSA and 131I-Man-BSA. We observed that the apparent intake rate as well as the amount of hydrolyzed GlcNAc-BSA are smaller than the corresponding values for Man-BSA. These differences were reduced by GlcNAc competitors (thyroglobulin and ovomucoid) or a weak base (chloroquine). Part of the internalized GlcNAc-BSA was released into the extracellular milieu at a higher rate and shorter half life (t1/2 = approximately 30 min) than the Man-BSA (t1/2 = approximately 8 h). Subcellular homing was first studied by cell fractionation after internalization using 125I-ovomucoid and 131I-BSA. During Percoll density gradient fractionation, endogenous thyroperoxidase was used to separate subsets of organelles involved in the biosynthetic exocytotic pathway. Incubation of the cell homogenate in the presence of DAB and H2O2 before cell fractionation give rise to a shift in the density of organelles containing 3.5 times more ovomucoid than BSA. Discontinuous sucrose gradient showed that: (a) thyroperoxidase was colocalized with galactosyltransferase-contraining organelles in Golgi-rich subfractions; and (b) that at every time studied from 10 to 100 min, the ovomucoid/BSA ratio was higher in these organelles than in other subfractions. Finally we also observed that: (a) ovomucoid sequestered in the Golgi-rich subfraction incorporated [3H]galactose; and (b) that part of internalized ovomucoid was localized on the Golgi stacks as well as elements of the trans-Golgi, as revealed by immunogold labeling on ultrathin cryosections. These data prove that in thyrocytes GlcNAc accessible sugar moieties on soluble internalized molecules are sufficient to trigger their recycling via the Golgi apparatus.

Systemic lupus erythematosus presenting with neurological disorders.

Six patients are described who developed a wide variety of neurological manifestations heralding systemic lupus erythematosus (SLE), which included epileptic seizures, stroke, peripheral polyradiculoneuropathy similar to Guillain-Barré syndrome, transverse myelopathy and multifocal disorders with remitting course mimicking multiple sclerosis. The peculiarity of these cases was that the neurological disorders remained the only manifestations of SLE for many years and the nervous system appeared to be the main target even after the development of systemic SLE. In five patients the prognosis was favourable and corticosteroid treatment led to prolonged remission.

Parkinson's disease in Ferrara, Italy, 1967 through 1987.

Epidemiological surveys on Parkinson's disease that have been carried out in different parts of the world have suggested that the disease is uniformly distributed in white populations. The position with regard to the Mediterranean peoples is still controversial, because of the large variation of the frequencies observed in the different areas that have been investigated. We therefore studied the frequency of Parkinson's disease in the Local Health Service of Ferrara, northeastern Italy (mean population, 187,000). Based on 394 patients, the mean incidence per year for the period from 1967 through 1987 was 10.01/100,000. The incidence rate of Parkinson's disease among cases with early onset was found to be statistically higher in rural areas as compared with urban ones (6.32/100,000 vs 3.11/100,000). Moreover, the study revealed a significantly higher incidence rate among agricultural workers (20.6/100,000). These results would seem to give further support to the hypothesis of a possible causal role of environmental factors that are mainly linked to agriculture, most likely due to the continual exposure to toxic agents in this area. However, further studies, which are not exclusively epidemiological, are necessary before any conclusions may be drawn, because many confounding variables may account for the results from surveys of this type.

Down regulation of hypertrophied follicular cell volume in thyroid hyperplastic gland.

In the present study, changes in thyroid follicular cell volume and its regulation have been investigated during the early involution of a hyperplastic goitre. Male Wistar rats were administered an iodine deficient diet for 6 months with propylthiouracil (PTU, 0.15%) during the last two months. At the end of iodine deficiency (day 0), some rats were killed and the others received a normal iodine diet. These rats were killed after different periods of iodine refeeding. Thyroid follicular cell volume was very high in hyperplastic gland whereas thyroid protein concentration was low. Thyroid follicular cell volume quickly decreased when rats were normally iodine refed, whereas thyroid protein concentration increased. Electron microscopal observations showed that thyroid follicular cells retained their endocrine aspect in hyperplastic state and throughout the iodine refeeding period. Using concomitant stereological and biochemical techniques, it is shown that the amount of cellular iodide and an unknown iodinated compound strongly increased during the early iodine refeeding. Plasma TSH was high on day 0 and remained at this level until day 8 whereas plasma T3 and T4 were low on day 0 and remained at this low level until day 4. The present data show that the involution of thyroid follicular cell volume is induced by iodide and mediated by an iodinated compound at least in the initial phase, and is independent of plasma TSH, T3, T4, so indicating the involvement of a thyroid autoregulatory mechanism. These changes in cell volume may be of importance in ion transport, i.e. in the metabolism of thyroid follicular cell during the early involution of the hyperplastic goitre.

Glycosylphosphatidylinositol is involved in the membrane attachment of proteins in granules of chromaffin cells.

Incubation at 37 degrees C or treatment of granule membranes of chromaffin cells with Staphylococcus aureus phosphatidylinositol-specific phospholipase C converted from an amphiphilic to a hydrophilic form two proteins with molecular masses of 82 and 68 kDa respectively. Their release is time- and enzyme-concentration-dependent. We showed that they were immunoreactive with an anti-(cross-reacting determinant) antibody known to be revealed only after removal of a diacylglycerol anchor. Furthermore, the action of HNO2 suggests the presence of a non-acetylated glucosamine residue in the determinant. This is one of the first reports suggesting that a glycosylphosphatidylinositol anchor might exist in membranes other than the plasma membrane. We showed that the 68 kDa protein is probably not the subunit of dopamine (3,4-dihydroxyphenethylamine) beta-hydroxylase, an enzyme present in granules in both soluble and membrane-associated forms.

Monoiodotyrosine formation during thyroglobulin processing in Golgi vesicles.

A golgi-enriched subfraction was obtained from porcine thyroid glands by differential centrifugation. When incubated in a suitable medium, these vesicles were able to concentrate iodide from the medium and bind it to protein. The iodination process was inhibited by methylmercapto-imidazole and was increased by the addition of an H2O2 generating system to the medium. Analysis of the protein content of the vesicles revealed the presence of 18 and 12-13 S thyroglobulin molecules, lacking mannose residues, and containing only monoiodotyrosine. It is concluded that in vitro, iodination can begin before exocytosis, in the smooth-surfaced vesicles derived from the golgi apparatus, as soon as N-acetylglucosamine is incorporated onto the pre-thyroglobulin molecule.

High-density lipoprotein composition in obesity: interrelationships with plasma insulin levels and body weight.

Hyperinsulinism may play a role in the development of atherosclerosis. In this study we analyzed the interrelationships between plasma glucose, insulin, body weight and high-density lipoproteins (HDL) in a group of obese women and faced the question of what is the effect of obesity on insulin, glucose and HDL relationships. HDL cholesterol was significantly lower, while HDL triglycerides resulted significantly higher in the obese women than in the controls. The two groups did not show any difference in the serum concentration of HDL apoprotein A-I and apoprotein A-II. There was an inverse correlation between fasting plasma glucose and summated means of glucose and insulin levels after an oral glucose tolerance test and HDL cholesterol in the two groups; on the contrary a positive relationship between the same parameters and HDL triglyceride occurred. HDL cholesterol was inversely related also to the weight index, while HDL triglyceride concentration was directly correlated with this parameter in the two groups. Partial correlation analysis demonstrates that, when exposed to similar plasma insulin and glucose levels, HDL cholesterol and triglyceride concentrations were no longer correlated with the weight index, and therefore that the significant correlations between these variables are likely to be due to the significant correlations of each of them with plasma glucose and insulin levels. Further studies clarifying the role of glucose and insulin in determining HDL composition would appear important.