Potential lung cancer screening outcomes using different age and smoking thresholds in the ANRS-CO4 French Hospital Database on HIV cohort.

OBJECTIVES: In most lung screening programmes, only subjects ≥ 55 years old and smoking ≥ 30 pack-years are eligible to undergo chest low-dose computed tomography. Whether the same criteria should apply to people living with HIV (PLHIV) is uncertain, given the increased lung cancer risks associated with immunodeficiency and high rates of smoking. We assessed different outcomes obtained from simulating one round of lung cancer screening in PLHIV using different age and smoking thresholds for eligibility. METHODS: Data from the French Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS)-CO4 French Hospital Database on HIV (FHDH) cohort of PLHIV and a national representative survey of PLHIV in care in 2011 (the ANRS-VESPA2 [enquête sur les personnes atteintes] study) were used to estimate the maximum proportion of incident lung cancers occurring between 2012 and 2016 that would have potentially been detected by screening in 2011. Secondary outcomes were numbers of eligible subjects in the cohort and numbers of subjects needed to screen (NNS) to detect one lung cancer. RESULTS: Among 77819 PLHIV in 2011 (median age 46 years; 66% men), 285 subjects subsequently developed lung cancer. Adoption of the US Preventive Services Task Force (USPSTF) recommendations (55-80 years; ≥ 30 pack-years) would have detected 31% of lung cancers at most. Lowering the minimum age to 50 and 45 years would have detected 49% and 60% of cancers, respectively, but would have greatly increased the number of eligible subjects and the NNS to detect one case of lung cancer. CONCLUSIONS: Use of the USPSTF criteria would have detected only a minority of lung cancers in a large French cohort of PLHIV in 2011. Screening PLHIV at younger ages (45 or 50 years) and/or the use of lower smoking thresholds (20 pack-years) may be beneficial, despite the consequently higher numbers of eligible subjects and NNS to detect one case of lung cancer, and should be evaluated in future studies.

Cancer-related cognitive impairment: an update on state of the art, detection, and management strategies in cancer survivors.

BACKGROUND: Advances in diagnostic and therapeutic strategies in oncology have significantly increased the chance of survival of cancer patients, even those with metastatic disease. However, cancer-related cognitive impairment (CRCI) is frequently reported in patients treated for non-central nervous system cancers, particularly during and after chemotherapy. DESIGN: This review provides an update of the state of the art based on PubMed searches between 2012 and March 2019 on 'cognition', 'cancer', 'antineoplastic agents' or 'chemotherapy'. It includes the most recent clinical, imaging and pre-clinical data and reports management strategies of CRCI. RESULTS: Evidence obtained primarily from studies on breast cancer patients highlight memory, processing speed, attention and executive functions as the most cognitive domains impaired post-chemotherapy. Recent investigations established that other cancer treatments, such as hormone therapies and targeted therapies, can also induce cognitive deficits. Knowledge regarding predisposing factors, biological markers or brain functions associated with CRCI has improved. Factors such as age and genetic polymorphisms of apolipoprotein E, catechol-O-methyltransferase and BDNF may predispose individuals to a higher risk of cognitive impairment. Poor performance on neuropsychological tests were associated with volume reduction in grey matter, less connectivity and activation after chemotherapy. In animals, hippocampus-based memory and executive functions, mediated by the frontal lobes, were shown to be particularly susceptible to the effects of chemotherapy. It involves altered neurogenesis, mitochondrial dysfunction or brain cytokine response. An important next step is to identify strategies for managing cognitive difficulties, with primary studies to assess cognitive training and physical exercise regimens. CONCLUSIONS: CRCI is not limited to chemotherapy. A multidisciplinary approach has improved our knowledge of the complex mechanisms involved. Nowadays, studies evaluating cognitive rehabilitation programmes are encouraged to help patients cope with cognitive difficulties and improve quality of life during and after cancer.

Behavioral cardiovascular risk factors in HIV-infected people in France: Diversity of profiles across groups requires an urgent and tailored preventive approach.

BACKGROUND: Among people living with HIV, cardiovascular risk could be markedly reduced through lifestyle improvement. However, to date behavioral cardiovascular risk factors (other than tobacco smoking) have been poorly investigated among them. Additionally, although co-occurrence of risk factors might amplify the deleterious effects of each risk factor, little is known about such risk factors clustering in this population. We aimed to examine levels, determinants and clustering of the major behavioral cardiovascular risk factors in the French HIV-infected population, in order to better target individuals with high risk profiles. METHODS: The ANRS-Vespa2 survey was conducted among a national representative sample of HIV-infected people followed at hospital in France in 2011. Frequency and co-occurrence of tobacco smoking, alcohol intake, low physical activity and obesity were assessed in the HIV-infected population, overall and in each of the distinctive socio-epidemiological group composing it (men who have sex with men, intravenous drug users, sub-Saharan African migrants, non-African heterosexuals). Individual characteristics associated with each of these indicators were investigated using multivariable Poisson regression models. RESULTS: The 2537 participants (median time since HIV-diagnosis: 12 years) included 39.4% men who have sex with men, 11.0% intravenous drug users, 23.5% sub-Saharan African migrants and 26.1% non-African heterosexuals. Overall, 29.4% were regular smokers, 13.8% were heavy drinkers, 14.8% lacked physical activity and 8.6% were obese. Half of the participants reported at least one risk factor with co-occurrence observed in 13.8% of the sample. However, those figures varied markedly across the groups. Main risk factors profiles were 1) regular smoking, heavy drinking, low physical activity alone or combined among intravenous drug users and men who have sex with men, 2) obesity and low physical activity usually alone among sub-Saharan African migrant women, 3) occurrence of the four risk factors separately or sometimes combined among sub-Saharan African migrant men and non-African heterosexuals. These risk factors were correlated with lower socioeconomic status and poorer health status. CONCLUSIONS: Those findings highlight the need to focus on all behavioral cardiovascular risk factors and co-occurrence (and not only on tobacco smoking) in HIV-infected people and to implement preventive approach tailored to the specific needs of the different socio-epidemiological groups.

Levels and determinants of breast and cervical cancer screening uptake in HIV-infected women compared with the general population in France.

OBJECTIVES: Cancer is a growing concern for HIV-infected people, and screening plays a major role in alleviating the burden it causes. We sought to investigate the levels and determinants of breast cancer screening (BCS) and cervical cancer screening (CCS) in HIV-infected women as compared with the general population. METHODS: The Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS)-Vespa2 study was conducted in 2011 in a national representative sample of 3022 HIV-infected hospital out-patients in France. The rates and correlates of BCS and CCS among HIV-infected women were compared with those in the general population using multivariate Poisson regression models. RESULTS: The BCS rate during the 2 years preceding the survey interview was 80.7% among HIV-infected women vs. 89.1% in the general population (P = 0.146). The CCS rate during the preceding 3 years was 88.1% among HIV-infected women vs. 83.1% in the general population (P = 0.021). During the preceding year, the CCS rate among HIV-infected women was 76.5%. The barriers to BCS and CCS were a low educational level [BCS: adjusted prevalence rate ratio 0.88; 95% confidence interval (CI) 0.80-0.97; CCS: adjusted prevalence rate ratio 0.91; 95% CI 0.83-0.99], not having supplementary health insurance (CCS: adjusted prevalence rate ratio 0.92; 95% CI 0.86-0.98), an irregular gynaecological follow-up (BCS: adjusted prevalence rate ratio 0.77; 95% CI 0.64-0.92; CCS: adjusted prevalence rate ratio 0.72; 95% CI 0.64-0.81) and a low CD4 count (BCS: adjusted prevalence rate ratio 0.83; 95% CI 0.71-0.97; CCS: adjusted prevalence rate ratio 0.78; 95% CI 0.63-0.98). The disparities in CCS uptake in terms of age, employment and gynaecological follow-up were less pronounced among HIV-infected women than in the general population. CONCLUSIONS: BCS and CCS uptake was not lower among HIV-infected women than in the general population, but CCS was suboptimal. Specificities in the profile of barriers to screening emerged.

Prevalence of and factors associated with depression among people living with HIV in France.

OBJECTIVES: Depression is common among people living with HIV (PLWHIV) and is associated with poorer therapeutic outcomes and risky behaviours. We sought to estimate the prevalence of major depressive episode (MDE) across PLWHIV groups, to compare this with its prevalence in the general population and to assess factors associated with it. METHODS: We used data from the Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS)-Vespa2 study, a national study on a representative sample of PLWHIV conducted in France in 2011. The short form of the depression module of the World Health Organization's Composite International Diagnostic Instrument (CIDI-SF) was used to characterize the occurrence of an MDE during the previous year. MDE prevalence was assessed among the various groups of PLWHIV and compared with that in the general population, accounting for the sociodemographic characteristics of the two populations, using multivariate Poisson regression models. The same method was used to assess associated factors. RESULTS: MDE prevalence was 28.1% among PLWHIV, ranging from 10.9 to 55.7% across groups. Compared with the general population by sex, regardless of sexual orientation and origin, MDE prevalence was 5.1-fold higher in HIV-infected men who have sex with men [95% confidence interval (CI) 3.9-6.6], 3.1-fold higher in non-sub-Saharan African (SSA) heterosexual men (95% CI 2.2-4.4), 1.6-fold higher in SSA migrant men (95% CI 0.9-2.6), 2.6-fold higher in non-SSA heterosexual women (95% CI 2.1-3.3), and 1.9-fold higher in SSA migrant women (95% CI 1.5-2.5). In the HIV-infected population, MDE was positively related to unemployment, material deprivation, disclosure, experience of discrimination, and untreated hepatitis C, and negatively related to age. CONCLUSIONS: The prevalence of depression varied across the different groups of PLWHIV, with levels much higher than in the general population. Moreover, there was a strong association with socioeconomic status and HIV experience.

Role of social status and social environment on net survival in patients with chronic lymphocytic leukemia: A high-resolution population-based study.

BACKGROUND: The prognostic roles of social status and social environment in chronic lymphocytic leukemia have been highlighted in some solid tumors but remain unclear in hematological malignancies. The objective of this study was to evaluate the influence of individual social status (with socioprofessional category, SPC) and social environment (with European deprivation index, EDI) on net survival in a high-resolution population with CLL. METHODS: We included CLL patients from the Regional Register of Hematological Malignancies in Normandy belonging to the French Network of Cancer Registries (Francim). The SPC variable was divided into 5 categories: farmers, craftsmen, higher employment, intermediate employment, and workers/employees. Net survival was used to estimate the excess of mortality in CLL independent of other possible causes of death using French life tables. Net survival was estimated with a nonparametric method (Pohar-Perme) and with a flexible excess mortality hazard model. Missing data were handled with multiple imputation. RESULTS: A total of 780 patients were included. The median follow-up was 7.9 years. The crude survival at 10 years was 50%, and the net survival at 10 years was 80%. In multivariate analysis, a higher age (EHR: 1.04 [1.01-1.07]), being a craftsman (EHRcraftsmen/higher.employment: 4.15 [0.86-20.15]), being a worker or an employee (EHRworkers.employees/higher.employment: 3.57 [1.19-10.7]), having a Binet staging of B or C (EHR: 3.43 [1.84-6.42]) and having a lymphocyte count > 15 G/L (EHR: 3.80 [2.17-6.65]) were statistically associated with a higher risk of excess mortality. EDI was not associated with excess mortality (EHR: 0.97 [0.90-1.04]). CONCLUSION: Socioprofessional category was a prognostic factor for an excess of mortality in CLL. Craftsmen and workers/employees shared a worse prognosis than workers with higher employment. The social environment was not a prognostic factor. Further work should be performed to explore causal epidemiologic or biological factors and other hematological malignancies.

Prognostic value of FDG-PET in Hodgkin lymphoma for posttreatment evaluation. Long term follow-up results.

Determining the viability of residual tumor masses is a great challenge after primary treatment of Hodgkin lymphoma. FDG-PET may play a crucial role in this procedure. In this study, files of 128 Hodgkin lymphoma patients were reviewed, who were treated in three Hungarian hematology centers between January 1995 and February 2005. CT scan showed residual tumor mass by all of them. Their median follow-up was 75.5 months from PET examination. The number of true-positive, true-negative, false-positive, false-negative subjects were 29, 83, 10, 6, respectively. Sensitivity of post-treatment FDG-PET was 83 %, specificity 93 %, positive predictive value 74 %, negative predictive value 93 %, and accuracy 88 %. The difference between the event free survival of PET positive and negative cases is highly significant (p=0.0000), according to the Mantel-Cox test. Our results in the largest cohort of patients, in accordance with literature, clearly indicates that patients with negative FDG-PET results are unlikely to progress or relapse during the longest follow-up.

Bretylium-induced voltage-gated sodium current in human lymphocytes.

Using the whole-cell variation of the patch-clamp technique it has been determined that 0.25-3 mM bretylium tosylate (BT) exerts a repolarizing effect on partially depolarized human lymphocytes. The repolarizing effect was ouabain (40 microM)-sensitive, and was inhibited by the removal of external Na+ or by the Na(+)-channel-blocker amiloride (10-44 microM), but K(+)-channel-blockers 4-aminopyridine (0.1-5 mM) and quinine (100 microM) had no effect. The drug induced a sodium dependent, amiloride-sensitive transient inward current reaching its maximum value approx. 20-30 s after the administration of BT and lasting for 6-10 min. This current was activated by depolarization within 25 ms at around -42 mV, its inactivation took about 2 s and its reversal potential was +24 +/- 5 mV. An increase in the intracellular sodium concentration (1.8-3.2 mM) has been observed upon the addition of BT by monitoring the SBFI fluorescence of the dye-loaded cells. It has been shown that whole-cell K+ currents are significantly decreased by BT. The existence of voltage and ligand (BT)-gated sodium channels has been postulated in human lymphocytes. These channels are thought to participate in the initiation of membrane repolarization in human lymphocytes, and thereby influence mitogenic or antigen-induced cell-activation processes.

Angiography-proven liver metastases explain low efficacy of lymph node dissections in medullary thyroid cancer patients.

AIM: To report the role of liver angiography in the staging of medullary thyroid cancer (MTC) patients. MATERIAL AND METHODS: Sixty MTC patients with persistent or recurrent hypercalcitonemia (n=49), a characteristic general symptom (diarrhea, n=4) or a normal basal calcitonin level without general symptoms (n=7) were investigated by dynamic liver CT, MRI and angiography between 06/1998 and 06/2002. RESULTS: Dual-phase CT and MRI investigations identified hepatic metastases with relatively low frequency (8/58 on MRI, and 7/60 on CT). Angiography indicated liver involvement in 54/60 cases. The hepatic metastases were typically multiple, hypervascular, small foci (only 13 foci measured >/=10 mm). With one exception significant disease progression was not observed over 5 years of follow-up. CONCLUSIONS: Liver angiography is a powerful tool to reveal hepatic metastases in MTC patients. Frequent, inoperable liver metastases in hypercalcitoninemic MTC patients demonstrate that secondary lymph node dissection is an inefficient technique for restoration of a normal calcitonin level.

Bretylium causes a K(+)-Na+ pump activation that is independent of Na+/H+ exchange in depolarized rat, mouse and human lymphocytes.

We have studied a bretylium tosylate induced increase of the membrane potentials of partially depolarized rat, mouse and human lymphocytes, using the potential sensitive dye, bis [1,3, dibutylbarbituric acid-(5) trimethine oxonol]. The extent of this repolarization is dose-dependent and decreased in magnitude as the temp was reduced from 37 degrees C to room temp. The repolarizing effect is inhibited by K(+)-Na(+)-pump blockers or lack of extracellular Na+. Sodium ion channel blockers are effective in abolishing repolarization only if applied prior to, or simultaneously with, bretylium. Activation of Na+/H+ exchange is not involved in the mechanism of the phenomenon as the latter is completely eliminated in the presence of 10 microM amiloride (concn of the diuretics having no measurable inhibition on the action of the exchanger). These data suggest that bretylium opens ligand- and voltage-gated Na+ channels, and repolarization occurs due to higher activity of the K(+)-Na(+)-pump stimulated by the enhanced intracellular Na+ accumulation.

On the biophysics of transmembrane signalling.

Transmembrane signalling involves a number of physical translocations, changes in proximity of membrane elements like receptor subunits, or sequestration of proteins from the membrane. The monitoring of such changes with flow cytometric energy transfer revealed a new putative subunit of the IL-2 receptor and a possible intermolecular interaction between HLA class I and class II antigens. Lateral diffusion of the components of the multi-subunit IL-2 receptor was also followed. Changes in the intracellular pH were considered as a measure of efficient signal transfer in a number of cases. An overview and critical comparison of data is presented in the paper.

Cerebral blood flow and glucose metabolism in mitochondrial disorders.

OBJECTIVE: To investigate cerebral metabolism by 2-[18F]fluorodeoxy-d-glucose (FDG) uptake using PET and cerebrovascular reverse capacity by transcranial Doppler sonography (TCD) in different mitochondrial diseases (mitochondrial myopathy; mitochondrial encephalopathy, lactacidosis, and stroke-like episodes [MELAS]; and chronic external ophthalmoplegia). BACKGROUND: Previous studies on individual patients with mitochondriopathies revealed abnormal accumulations of mitochondria in endothelium, smooth muscle cells, and pericytes of blood vessels in different parts of the nervous system (cerebrum, cerebellum, sural nerve) and skeletal muscle. On this basis, some investigators suggested a pathogenic role of vascular involvement in the MELAS syndrome and other encephalopathies. smhd1 DESIGN/METHODS: The authors investigated neuronal metabolism and cerebrovascular involvement with PET in 5 cases and with TCD with acetazolamide stimulation in 15 cases. The patients were divided into three groups: 1) interictal MELAS (n = 4); 2) progressive external ophthalmoplegia (n = 6); and 3) pure mitochondrial myopathy and neuropathy (n = 5). The results were compared with those from matched normal control subjects. The diagnoses were based on clinical phenotype as well as histopathologic and molecular analysis. RESULTS: Cerebral glucose uptake was impaired in all patients, both with and without CNS symptoms, particularly in the occipital and temporal lobes. The vasoreactivity of the small arterioles to acetazolamide did not differ significantly between the patients and healthy control subjects or between the different groups of mitochondrial disorders. CONCLUSIONS: MELAS does not appear to be a functional disturbance of arterioles leading to an ischemic vascular event. The clinical symptoms in MELAS are not the result of a mitochondrial angiopathy but are the consequences of a mitochondrial cytopathy affecting neurons or glia. There is no correlation between the decreased glucose metabolism and the duration of the disease.

Hypo-osmotic shock induces an osmolality-dependent permeabilization and structural changes in the membrane of carp sperm.

We carried out spectrofluorimetric and flow cytometric measurements to investigate the effect of hypo-osmotic shock on cell membranes of common carp sperm. The time course of the permeability of the sperm cell membrane, as monitored by DNA-related propidium iodide (PI) fluorescence, was followed for 30 min after dilution of semen in hypo-osmotic environments of different ionic strengths. Spectrofluorimetric measurements indicated a continuous increase in the total PI emission intensity of a sperm suspension. Cell-by-cell flow cytometric measurements suggested that the permeability changes were of the all-or-none type. The permeabilized fraction of cells in the individual samples was time and osmolality dependent. The number and percentage of cells in which DNA was stained by PI increased gradually over time and reached a steady-state plateau value after 5-15 min. This equilibrium fraction of cells with a PI-permeable cytoplasmic membrane displayed an inverse relationship with the osmolality of the diluent, having a near 100% value for fresh water and distilled water. Dilution of sperm in hypo-osmotic medium brought about a fast decrease in the forward light-scattering signal on a short time scale compared to the pre-steady-state time of the permeabilization. With the addition of extracellular Ca2+ (1.8 mM), restoration of the light scattering signal was observed. Permeabilization of the membrane and restoration of light scattering were not coincident in time. We propose a two-dimensional reorganization of the lipid structure as the underlying mechanism of the latter process.

Dynamic physical interactions of plasma membrane molecules generate cell surface patterns and regulate cell activation processes.

Molecular interaction and transmembrane signal transducing events generate a very dynamic and ever changing "pattern" in the plasma membranes. Lymphocytes, the key functional elements of the immune system, are eminently suited to be the primary targets to investigate these proximity, mobility, or other physical-chemical changes in their plasma membranes. Recently, a number of experiments suggested that processed peptides from antigens can bind specific components of MHC molecules (Elliott et al., 1991). This is certainly a way to alter their structure. Cell surface patterns of topological nature, assembly and disassembly of oligomeric receptor structure like the IL-2 receptor have been investigated by sophisticated biophysical techniques. The dynamic changes in the two-dimensional cell surface pattern and intramolecular conformational changes within this "larger" macro-pattern may have a strong regulatory role in signal transducing and intercellular recognition processes. Recent data on these problems are presented together with brief and critical discussions.

Ion channel activity and transmembrane signaling in lymphocytes.

Transmembrane signalling refers to the process of transfer of information from the extracellular world into the intracellular space. The information is transduced through several possible pathways. The significance of cell surface dynamics, ion channel activity and drug effects are discussed in the signal transmission, with special reference to Na+ channels and the Ca2+ sensitive potassium channels.

Right prefrontal activation produced by arterial baroreceptor stimulation: a PET study.

This study was performed to test the hypothesis of greater right hemispheric involvement in the processing of baroreceptor stimuli. Carotid sinus baroreceptors were stimulated by rhythmically decreasing air pressure in a neck chamber, and under control conditions the thorax was stimulated in a similar manner. Changes in regional cerebral blood flow (rCBF) were measured by PET. Baroreceptor stimulation resulted in rCBF increase in the right anterior-inferior prefrontal cortex (Brodmann areas (BA) 10/44/47) and bilaterally in BA 6/8. We conclude that in at least some stages of baroreceptor information processing the right hemisphere plays a greater role than the left hemisphere.

Radiation myelopathy with partial functional recovery: PET evidence of long-term increased metabolic activity of the spinal cord.

Postoperative telecobalt irradiation was performed with a biologically effective extrapolated response dose of 165 Gy2 delivered to the spinal cord of a papillary thyroid cancer patient. Incomplete cervical transection developed, followed by a gradual functional improvement, which is still continuing 8 years after radiotherapy. Between the 6th and 8th years of the clinical course, positron emission tomography investigations demonstrated an increased 18F-deoxyglucose accumulation and (15)O-butanol perfusion, but negligible 11C-methionine uptake in the irradiated spinal cord segment. We suggest that the increased metabolism and perfusion, and the lack of detectable protein synthesis may be related to the increased energy demands of action potential conduction, due to the higher than normal density of sodium channels along demyelinated axons displaying restored conduction.

FDG PET imaging in hereditary thyroid cancer.

AIM: To report the role of different imaging methods in staging individuals with multiple endocrine neoplasia 2A (MEN2A) or familial medullary thyroid carcinoma (FMTC). MATERIAL AND METHODS: Fourteen newly diagnosed gene carriers underwent cervical ultrasound scanning (US), cervical and mediastinal CT, MRI and whole-body meta-[131I]iodobenzylguanidine (MIBG) scintigraphy and [18F]fluorodeoxyglucose (FDG) PET scanning. RESULTS: US identified seven true primary cancer. CT and MRI located only tumors > or =5 mm in diameter. MIBG scintigraphy and FDG PET could not identify MTC foci within the thyroid. Whole-body FDG PET identified two true-positive and one false-positive lymph node metastases. MIBG scintigraphy did not identify lymph node metastases. Total thyroidectomy was performed in 12 cases, and subtotal thyroidectomy in two subjects. CONCLUSIONS: Whole-body FDG PET and cervical US help stage individuals carrying mutant genes verifying MEN2A or FMTC.

Cerebral effects of a single dose of intravenous vinpocetine in chronic stroke patients: a PET study.

The effects of vinpocetine (Cavinton) on the cerebral glucose metabolism of chronic stroke patients are studied with positron emission tomography. The regional and global cerebral metabolic rates of glucose (CMRglu) and the kinetic constants related to them are quantified before and after single-dose intravenous vinpocetine treatment. These measurements are completed with transcranial Doppler sonography and single photon emission computed tomography to explore the possible mechanisms underlying the resulting changes in glucose uptake and metabolism in the brain. The authors' findings indicate that a single-dose vinpocetine treatment, although it does not affect significantly the regional or global metabolic rates of glucose, improves significantly the transport of glucose (both uptake and release) through the blood-brain barrier in the whole brain, the entire contralateral hemisphere, and in the brain tissue around the infarct area of the symptomatic hemisphere. These changes are in accord with increased blood flow in the entire contralateral hemisphere as well as decreased blood flow velocity and increased peripheral vessel resistance in the entire symptomatic hemisphere.

A continuous assay method for glycogen synthesis from UDPglucose.

A light scattering assay was developed for continuous monitoring of glycogen synthesis from UDPglucose. A close linear correlation between light-scattering signal and the amount of radioactively labelled glucose incorporated into glycogen suggests that the scattering signal is determined by the average molecular weight of the glycogen molecules. The method has the advantage of continuity, and it is suitable to follow the time course of the reaction at different conditions and to determine the initial rate of glycogen synthesis in a relatively simple and fast way. The possibility of measurement of glycogen synthase activity in muscle extracts was also tested.