Neuromuscular defects after infection with a beta coronavirus in mice

COVID-19 affects primarily the lung. However, several other systemic alterations, including muscle weakness, fatigue and myalgia have been reported and may contribute to the disease outcome. We hypothesize that changes in the neuromuscular system may contribute to the latter symptoms observed in COVID-19 patients. Here, we showed that C57BL/6J mice inoculated intranasally with the murine betacoronavirus hepatitis coronavirus 3 (MHV-3), a model for studying COVID-19 in BSL-2 conditions that emulates severe COVID-19, developed robust motor alterations in muscle strength and locomotor activity. The latter changes were accompanied by degeneration and loss of motoneurons that were associated with the presence of virus-like particles inside the motoneuron. At the neuromuscular junction level, there were signs of atrophy and fragmentation in synaptic elements of MHV-3-infected mice. Furthermore, there was muscle atrophy and fiber type switch with alteration in myokines levels in muscles of MHV-3-infected mice. Collectively, our results show that acute infection with a betacoronavirus leads to robust motor impairment accompanied by neuromuscular system alteration.

Transactivation activity and nucleocytoplasmic transport of β-catenin are independently regulated by its C-terminal end

The key protein in the canonical Wnt pathway is β-catenin, which is phosphorylated both in absence and presence of Wnt signals by different kinases. Upon activation in the cytoplasm, β-catenin can enter into the nucleus to transactivate target gene expression, many of which are cancer-related genes. The mechanism governing β-catenin's nucleocytoplasmic transport has been recently unvealed, although phosphorylation at its C-terminal end and its functional consequences are not completely understood. Serine 646 of β-catenin is a putative CK2 phosphorylation site and lies in a region which has been proposed to be important for its nucleocytoplasmic transport and transactivation activity. This residue was mutated to aspartic acid mimicking CK2-phosphorylation and its effects on β-catenin activity as well as localization were explored. β-Catenin S6464D did not show significant differences in both transcriptional activity and nuclear localization compared to the wild-type form, but displayed a characteristic granular nuclear pattern. Three-dimensional models of nuclei were constructed which showed differences in number and volume of granules, being those from β-catenin S646D more and smaller than the wild-type form. FRAP microscopy was used to compare nuclear export of both proteins which showed a slightly higher but not significant retention of β-catenin S646D. Altogether, these results show that C-terminal phosphorylation of β-catenin seems to be related with its nucleocytoplasmic transport but not transactivation activity.

FUS-SMN protein interactions link the motor neuron diseases ALS and SMA

Mutations in the RNA binding protein FUS cause amyotrophic lateral sclerosis (ALS), a fatal adult motor neuron disease. Decreased expression of SMN causes the fatal childhood motor neuron disorder spinal muscular atrophy (SMA). The SMN complex localizes in both the cytoplasm and nuclear Gems, and loss of Gems is a cellular hallmark of fibroblasts in patients with SMA. Here, we report that FUS associates with the SMN complex, mediated by U1 snRNP and by direct interactions between FUS and SMN. Functionally, we show that FUS is required for Gem formation in HeLa cells, and expression of FUS containing a severe ALS-causing mutation (R495X) also results in Gem loss. Strikingly, a reduction in Gems is observed in ALS patient fibroblasts expressing either mutant FUS or TDP-43, another ALS-causing protein that interacts with FUS. The physical and functional interactions among SMN, FUS, TDP-43, and Gems indicate that ALS and SMA share a biochemical pathway, providing strong support for the view that these motor neuron diseases are related.

Pervasive synaptic branch removal in the mammalian neuromuscular system at birth

VIDEO ABSTRACT

Using light and serial electron microscopy, we show profound refinements in motor axonal branching and synaptic connectivity before and after birth. Embryonic axons become maximally connected just before birth when they innervate ∼10-fold more muscle fibers than in maturity. In some developing muscles, axons innervate almost every muscle fiber. At birth, each neuromuscular junction is coinnervated by approximately ten highly intermingled axons (versus one in adults). Extensive die off of terminal branches occurs during the first several postnatal days, leading to much sparser arbors that still span the same territory. Despite the extensive pruning, total axoplasm per neuron increases as axons elongate, thicken, and add more synaptic release sites on their remaining targets. Motor axons therefore initially establish weak connections with nearly all available postsynaptic targets but, beginning at birth, massively redistribute synaptic resources, concentrating many more synaptic sites on many fewer muscle fibers. Analogous changes in connectivity may occur in the CNS.

Shared resistance to aging and ALS in neuromuscular junctions of specific muscles

Normal aging and neurodegenerative diseases both lead to structural and functional alterations in synapses. Comparison of synapses that are generally similar but respond differently to insults could provide the basis for discovering mechanisms that underlie susceptibility or resistance to damage. Here, we analyzed skeletal neuromuscular junctions (NMJs) in 16 mouse muscles to seek such differences. We find that muscles respond in one of three ways to aging. In some, including most limb and trunk muscles, age-related alterations to NMJs are progressive and extensive during the second postnatal year. NMJs in other muscles, such as extraocular muscles, are strikingly resistant to change. A third set of muscles, including several muscles of facial expression and the external anal sphinter, succumb to aging but not until the third postnatal year. We asked whether susceptible and resistant muscles differed in rostrocaudal or proximodistal position, source of innervation, motor unit size, or fiber type composition. Of these factors, muscle innervation by brainstem motor neurons correlated best with resistance to age-related decline. Finally, we compared synaptic alterations in normally aging muscles to those in a mouse model of amyotrophic lateral sclerosis (ALS). Patterns of resistance and susceptibility were strikingly correlated in the two conditions. Moreover, damage to NMJs in aged muscles correlated with altered expression and distribution of CRMP4a and TDP-43, which are both altered in motor neurons affected by ALS. Together, these results reveal novel structural, regional and molecular parallels between aging and ALS.

Regulation of glycinergic and GABAergic synaptogenesis by brain-derived neurotrophic factor in developing spinal neurons

Brain-derived neurotrophic factor (BDNF) effects on the establishment of glycinergic and GABAergic transmissions in mouse spinal neurons were examined using combined electrophysiological and calcium imaging techniques. BDNF (10 ng/ml) caused a significant acceleration in the onset of synaptogenesis without large effects on the survival of these neurons. Amplitude and frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) associated to activation of glycine and GABA(A) receptors were augmented in neurons cultured with BDNF. The neurotrophin effect was blocked by long term tetrodotoxin (TTX) addition suggesting a dependence on neuronal activity. In addition, BDNF caused a significant increase in glycine- and GABA-evoked current densities that partly explains the increase in synaptic transmission. Presynaptic mechanisms were also involved in BDNF effects since triethylammonium(propyl)-4-(2-(4-dibutylamino-phenyl)vinyl)pyridinium (FM1-43) destaining with high K(+) was augmented in neurons incubated with the neurotrophin. The effects of BDNF were mediated by receptor tyrosine kinase B (TrkB) and mitogen-activated protein kinase kinase (MEK) activation since culturing neurons with either (9S,10R,12R)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'- kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester (K252a) or 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one (PD98059) blocked the augmentation in synaptic activity induced by the neurotrophin.

Anti-homeostatic synaptic plasticity of glycine receptor function after chronic strychnine in developing cultured mouse spinal neurons

In this study, we describe a novel form of anti-homeostatic plasticity produced after culturing spinal neurons with strychnine, but not bicuculline or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Strychnine caused a large increase in network excitability, detected as spontaneous synaptic currents and calcium transients. The calcium transients were associated with action potential firing and activation of gamma-aminobutyric acid (GABA(A)) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors as they were blocked by tetrodotoxin (TTX), bicuculline, and CNQX. After chronic blockade of glycine receptors (GlyRs), the frequency of synaptic transmission showed a significant enhancement demonstrating the phenomenon of anti-homeostatic plasticity. Spontaneous inhibitory glycinergic currents in treated cells showed a fourfold increase in frequency (from 0.55 to 2.4 Hz) and a 184% increase in average peak amplitude compared with control. Furthermore, the augmentation in excitability accelerated the decay time constant of miniature inhibitory post-synaptic currents. Strychnine caused an increase in GlyR current density, without changes in the apparent affinity. These findings support the idea of a post-synaptic action that partly explains the increase in synaptic transmission. This phenomenon of synaptic plasticity was blocked by TTX, an antibody against brain-derived neurotrophic factor (BDNF) and K252a suggesting the involvement of the neuronal activity-dependent BDNF-TrkB signaling pathway. These results show that the properties of GlyRs are regulated by the degree of neuronal activity in the developing network.

Changes on the properties of glycine receptors during neuronal development

Glycine receptors (GlyRs) play a major role in the excitability of spinal cord and brain stem neurons. During development, several properties of these receptors undergo significant changes resulting in major modifications of their physiological functions. For example, the receptor structure switches from a monomeric alpha or heteromeric alpha 2 beta in immature neurons to an alpha 1 beta receptor type in mature neurons. Together with these changes in receptor subunits, the postsynaptic cluster size increases with development. Parallel to these modifications, the apparent receptor affinity to glycine and strychnine, as well as that of Zn(2+) and ethanol increases with time. The mature receptor is characterized by a slow desensitizing current and high sensitivity to modulation by protein kinase C. Also, the high level of glycinergic transmission in immature spinal neurons modulates neuronal excitability causing membrane depolarization and changes in intracellular calcium. Due to these properties, chronic inhibition of glycinergic transmission affects neurite outgrowth and produces changes in the level of synaptic transmission induced by GABA(A) and AMPA receptors. Finally, the high level of plasticity found in immature GlyRs is likely associated to changes in cytoskeleton dynamics.

Modulation of glycine-activated ion channel function by G-protein betagamma subunits

Glycine receptors (GlyRs), together with GABA(A) and nicotinic acetylcholine (ACh) receptors, form part of the ligand-activated ion channel superfamily and regulate the excitability of the mammalian brain stem and spinal cord. Here we report that the ability of the neurotransmitter glycine to gate recombinant and native ionotropic GlyRs is modulated by the G protein betagamma dimer (Gbetagamma). We found that the amplitude of the glycine-activated Cl- current was enhanced after application of purified Gbetagamma or after activation of a G protein-coupled receptor. Overexpression of three distinct G protein alpha subunits (Galpha), as well as the Gbetagamma scavenger peptide ct-GRK2, significantly blunted the effect of G protein activation. Single-channel recordings from isolated membrane patches showed that Gbetagamma increased the GlyR open probability (nP(o)). Our results indicate that this interaction of Gbetagamma with GlyRs regulates both motor and sensory functions in the central nervous system.

Early expression of glycine and GABA(A) receptors in developing spinal cord neurons. Effects on neurite outgrowth

Using fluorometric and immunocytochemical techniques, we found that high glycine concentrations or blockade of glycine receptors increases neurite outgrowth in developing mouse spinal cord neurons. Glycine- and GABA(A)-activated currents were demonstrated during applications of glycine and GABA (50-100 microM) in 5 days in vitro (DIV) neurons. Long application (> or =10 min) of 100 microM glycine desensitized the membrane response by more than 95%. Application of glutamate in the absence of external Mg(2+), at several membrane potentials, did not produce any detectable membrane response in these cells. Immunocytochemical studies with NR1 and GluR1 antibodies showed a delayed appearance of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors respectively. Spontaneous synaptic activity was readily observed in 5 DIV neurons. The use of various receptor antagonists (strychnine, bicuculline, DL-2-amino-5-phosphonovalerate [APV], 6-cyano-7-nitroquinoxaline-2,3-dione [CNQX]) revealed that this activity was predominantly glycinergic, and to a smaller extent, GABAergic. In the presence of bicuculline, APV and CNQX, we detected abundant spontaneous depolarizing potentials which often reached the action potential threshold. Further evidence for functional synaptic activity was provided by the detection of co-localization of gephyrin and synaptophysin at 5 DIV using confocal microscopy. Fluorometric studies with Fluo-3, a Ca(2+) indicator, in 5 DIV cultures showed the presence of spontaneous fluctuations associated with tetrodotoxin-sensitive synaptic events. The number of neurons displaying these fluctuations was significantly increased (>100%) when the cells were bathed in a strychnine-containing solution. On the other hand, these synaptically mediated Ca(2+) events were blocked by the co-application of strychnine and bicuculline. This suggests that glycine and GABA(A) receptors provide a fundamental regulation of both neuronal excitability and intracellular Ca(2+) at this early time of development.The neurotrophic effects of agonists and antagonists for glycine, GABA(A) and glutamate receptors were examined in neurons cultured for 2 or 5 DIV. From all the agonists used, only high concentrations of glycine increased neurite outgrowth in 5 DIV neurons. We found that strychnine also increased neurite outgrowth, whereas tetrodotoxin (1 microM), nimodipine (4 microM) and bicuculline (20 microM) completely blocked it. On the other hand, APV (50 microM) and CNQX (20 microM) were unable to affect neurite outgrowth. These data suggest that spinal glycine receptors depress neurite outgrowth by shunting neuronal excitability. Outgrowth induction possibly results from the enhanced activity found after the inhibition of glycinergic activity. We postulate that this resets the intracellular calcium at a concentration that favors neurite outgrowth.

Elevated expression of glucose transporter-1 in hypothalamic ependymal cells not involved in the formation of the brain-cerebrospinal fluid barrier

Glucose transporters play an essential role in the acquisition of glucose by the brain. Elevated expression of glucose transporter-1 has been detected in endothelial cells of the blood-brain barrier and in choroid plexus cells of the blood-cerebrospinal fluid barrier. On the other hand, there is a paucity of information on the expression of glucose transporters in the ependymal cells that line the walls of the cerebral ventricles. The tanycytes are specialized ependymal cells localized in circumventricular organs such as the median eminence that can be segregated into at least three types, alpha, beta1 and beta2. The beta2 tanycytes form tight junctions and participate in the formation of the cerebrospinal fluid-median eminence barrier. Using immunocytochemistry and in situ hybridization, we analyzed the expression of hexose transporters in rat and mouse hypothalamic tanycytes. In both species, immunocytochemical analysis revealed elevated expression of glucose transporter-1 in alpha and beta1 tanycytes. Intense anti-glucose transporter-1 staining was observed in cell processes located throughout the arcuate nucleus, in the end-feet reaching the lateral sulcus of the infundibular region, and in cell processes contacting the hypothalamic capillaries. On the other hand, there was very low expression of glucose transporter-1 in beta2 tanycytes involved in barrier function. In contrast with the results of the cytochemical analysis, in situ hybridization revealed that tanycytes alpha, beta1, and beta2 express similar levels of glucose transporter-1 mRNA. Further analysis using anti-glial fibrillary acidic protein antibodies to identify areas rich in astrocytes revealed that astrocytes were absent from areas containing alpha and beta1 tanycytes, but were abundant in regions containing the barrier-forming beta2 tanycytes. Overall, our data reveal a lack of correlation between participation in barrier function and expression of glucose transporter-1 in hypothalamic tanycytes. Given the virtual absence of astrocytes in areas rich in alpha and beta1 tanycytes, we speculate whether the tanycytes might have astrocyte-like functions and participate in the metabolic coupling between glia and neurons in the hypothalamic area.

Neurite outgrowth in developing mouse spinal cord neurons is modulated by glycine receptors

The effect of glycine receptor activation on neurite outgrowth and survival was studied in 5 DIV (days in vitro) spinal neurons. These neurons were depolarized by spontaneous synaptic activity and by glycine, but not by glutamate. These responses were accompanied by increases in intracellular calcium concentration measured with Indo-1 and Fluo-3. Glycine (100 microM, 48 h) increased (46 +/- 6%) the number of primary neurites and total neuritic length. This effect was mediated by synaptic activity and calcium influx because TTX (1 microM) and nimodipine (4 microM) blocked the stimulatory effect of glycine. Neuronal survival, on the other hand, was not affected. This study shows for the first time the modulatory effect of glycine receptors on spinal neuron development.

Ethanol affects the function of a neurotransmitter receptor protein without altering the membrane lipid phase

Using patch-clamp and fluorescence techniques we found that ethanol (10-200 mM) potentiated strychnine-sensitive glycine receptors without having detectable effects on lipid order parameters in mouse spinal cord neurons. Hepthanol (0.01-1 mM), in contrast, did not affect the glycine current, but it altered the core and surface of spinal neuron membranes as detected by changes in 1,6-diphenyl-1,3,5-hexatriene (DPH) and Laurdan fluorescence parameters. These findings support the idea that ethanol affects these membrane proteins without changing lipid fluidity.

Changes in the properties of developing glycine receptors in cultured mouse spinal neurons

We studied several neurophysiological properties of in vitro maturing glycine receptors in mouse spinal cord neurons cultured for various times: 3-7 days (early), 10-12 days (intermediate), and 17-24 days (mature), using whole-cell and gramicidin-perforated techniques. The glycine-activated Cl- conductance increased about 6-fold during in vitro development, and the current density increased from 177+/-42 pA/pF in early to 504+/-74 pA/pF in mature neurons. The sensitivity to glycine increased transiently from 39+/-2.8 microM in early neurons to 29+/-1 microM in intermediate neurons. Using whole-cell recordings, we found that ECl did not change during development. With the gramicidin-perforated technique, on the other hand, ECl shifted from -27 to -52 mV with development. Thus, immature neurons were depolarized by the activation of glycine receptors, whereas mature neurons were hyperpolarized. The current decayed (desensitized) during the application of 500 microM glycine. The decay was single exponential and the time constant increased from 2,212+/-139 msec in early neurons to 4,580+/-1,071 msec in mature neurons. Picrotoxin (10 microM) inhibited the current to a larger extent in early neurons (46+/-6% of control), and the sensitivity of these receptors to strychnine (IC50) increased from 23+/-3 nM to 9+/-1 nM in mature neurons. In conclusion, several properties of spinal glycine receptors changed during in vitro neuronal maturation. This indicates that, similar to GABA(A) receptors, the functions of these receptors are developmentally regulated. These changes should affect the excitability of spinal neurons as well as other maturation processes.

Differential intracellular regulation of cortical GABA(A) and spinal glycine receptors in cultured neurons

Using patch-clamp techniques we studied several aspects of intracellular GABA(A) and glycine Cl- current regulation in cortical and spinal cord neurons, respectively. Activation of PKA with a permeable analog of cyclic AMP (cAMP) produced a potentiation of the Cl- current activated with glycine, but not of the current induced with GABA. The inactive analog was without effect. Activation of PKC with 1 microM PMA reduced the amplitude of the GABA(A) and glycine currents. Internal application of 1 mM cGMP, on the other hand, had no effect on the amplitude of either current. The amplitude of these inhibitory currents changed slightly during 20 min of patch-clamp recording. Internal perfusion of the neurons with 1 microM okadaic acid, a phosphatase inhibitor, induced potentiation in both currents. The amplitude of GABA(A) and glycine currents recorded with 1 mM internal CaCl2 and 10 mM EGTA (10 nM free Ca2+) decayed by less than 30% of control. Increasing the CaCl2 concentration to 10 mM (34 microM free Ca2+) induced a transient potentiation of the GABA(A) current. A strong depression of current amplitude was found with longer times of dialysis. The glycine current, on the contrary, was unchanged by increasing the intracellular Ca2+ concentration. Activation of G proteins with internal FAl4- induced an inhibition of the GABA(A) current, but potentiated the amplitude of the strychnine-sensitive Cl- current. These results indicate that GABA(A) and glycine receptors are differentially regulated by activation of protein kinases, G proteins and Ca2+. This conclusion supports the existence of selectivity in the intracellular regulation of these two receptor types.

Potentiation of the glycine-activated Cl- current by ethanol in cultured mouse spinal neurons

Ethanol (1-200 mM), a potent depressor of respiration and motor activity, potentiated the inhibitory Cl- current activated by glycine in 80% of the cultured mouse spinal (n = 236) neurons studied. Ethanol (100 mM) had no effect on the gamma-aminobutyric acidA current and slightly inhibited the N-methyl-D-aspartate current in these neurons. Ethanol increased the affinity of the receptors to glycine without changing the maximal amplitude of the glycine current. The EC50 was reduced from 54 +/- 3 microM in the absence of ethanol to 38 +/- 5 microM in the presence of ethanol. Activation of GTP binding proteins in the neurons with intracellular guanosine-5'-0-(2-thiotriiphosphate) (0.5 mM) enhanced the effect of ethanol, and application of a similar concentration of guanosine 5'-0-(2-thiodiphosphate had an inhibitory effect upon the current potentiation. The potentiating effect of ethanol persisted after culturing the neurons with pertussis toxin, but not with cholera toxin, an irreversible activator of Gs. Activation of cyclic AMP-dependent protein kinase by cyclic AMP and Sp-adenosine-3',5'-cyclic monophosphothioate triethylamine salt, but not of protein kinase C and protein kinase G, potentiated the glycine current. The effect of Sp-adenosine-3',5'-cyclic monophosphothioate triethylamine salt, but not of ethanol, was inhibited completely by the protein kinase A peptide inhibitor. These results suggest that ethanol potentiates the glycine activated Cl- current by modifying a signal transduction step other than protein kinase A.

[Urinary albumin excretion in non-insulin-dependent diabetic patients. Effects of an angiotensin-converting enzyme inhibitor]

BACKGROUND

Microalbuminuria in diabetic patients is diagnostic of early renal involvement and angiotensin converting enzyme inhibitors reduce albumin excretion in these subjects.

AIM

To assess the effects of an angiotensin converting enzyme inhibitor on urinary albumin excretion in non insulin dependent diabetic patients.

PATIENTS AND METHODS

Diabetic patients with normal blood pressure were randomly assigned to receive enalapril 10 mg/day or placebo and followed during 18 months. Those with high blood pressure were randomly assigned to receive enalapril or acebutolol in doses necessary to normalize blood pressure and followed during 12 months. Every three months, urinary albumin excretion was measured in a four hour urine sample by radioimmunoassay.

RESULTS

One hundred fifty two patients were recruited for the study and 46 were lost from follow up. In 17 subjects with normal blood pressure initial urinary albumin excretion below cutoff values (30 mg/24 h) and treated with enalapril, this parameter did not change; in 20 treated with placebo, it increased from 5.8 +/- 6.1 to 18.2 +/- 7.5 mg/24 h. In 11 patients with normal pressure and increased initial urinary albumin, this parameter did not change with enalapril and increased in 10 with placebo from 87.3 +/- 75.1 to 253.6 +/- 61.1 mg/24 h. In hypertensive patients with normal urinary albumin excretion, no changes in this parameter were observed in those treated with acebutolol (n = 10) or enalapril (n = 14). In hypertensives with high urinary albumin excretion, it decreased from 119.2 +/- 8.5 to 40.0 +/- 4.7 mg/24 h with enalapril treatment (n = 12), and no change was observed in those treated with acebutolol (n = 11).

CONCLUSIONS

Enalapril decreases urinary albumin excretion in non insulin dependent diabetic patients.

Effects of benzodiazepine receptor ligands on isolated rat superior cervical ganglia neurons

We studied the effects of diazepam, CL 218,872, Ro 15-1788, beta-CCM and Ro 15-4513 on the gamma-aminobutyric acid-activated current in adult and newborn rat superior cervical ganglion neurons. Diazepam (10-1,000 nmol/l) potentiated the current in a concentration-dependent manner. CL 218,872 was less effective and weaker than diazepam. The other ligands reduced the amplitude of the current. These peripheral receptors might be involved in some of the side effects of benzodiazepines.

[Post-pancreatitis diabetes: clinical experience in 40 cases]

The clinical features and evolution of 40 patients with diabetes mellitus secondary to chronic pancreatitis were reviewed and compared with 40 insulin dependent diabetics, matched for the disease duration. The diagnosis of pancreatitis was confirmed by the existence of pancreatic calcifications, surgery or autopsy and was associated to alcoholism in males and biliary diseases in females. Diabetes appeared, as a mean, 3 years after the diagnosis of pancreatitis. Ninety percent of subjects required insulin and, in males, these requirements were higher than their matched controls. Episodes of ketoacidosis were less frequent than in insulin dependent patients (8 vs 48% p < 0.001) and pulmonary tuberculosis had a higher prevalence (22.5 vs 5% p < 0.01). Nephropathy was observed with equal frequency in both groups but the incidence of retinopathy was higher in postpancreatic diabetics (38 vs 20% p < 0.01). It is concluded that the features of diabetes secondary to chronic pancreatitis are similar to those of insulin dependent diabetes, with some quantitative differences.

[Acipimox in primary hyperlipidemias: safety and efficacy evaluated in six months]

The efficacy and tolerance of 750 mg of Acipimox was tested in 38 pts with primary dyslipidemias: 20 type IIa, 12 type IIb, and 6 type IV. All pts had been poor responders to a 2 month diet according to the recommendations of the National Cholesterol Education Program. Clinical examination, eye fundus, and the following laboratory tests: total cholesterol (TC), HDL, triglycerides (TG), total bilirubin, alkaline phosphatase, oxalacetic and pyruvic transaminases, uric acid, plasmatic creatinine, albumin, postprandial glucose test, hematocrit, white blood and platelet count were performed 60 days before drug initiation, 60 and 180 days after treatment had been started. No side effects were observed (myositis, visual gastrointestinal). 50% of the pts had slight to moderate flushing which appeared the first 3 days and lasted 14 +/- 7 days after treatment had been started. Plasmatic creatinine increased from 0.89 to 1.86 mg/dl in pt with one kidney, returning to normal levels 30 days after Acipimox interruption. After 180 days of therapy in the IIa group TC was -27% (p < 0.001), HDL + 15% (p < 0.001); in the IIb group: TC-23% (p < 0.001), HDL +9% (NS), TG -48% (p < 0.001); and in the IV group: TC-10% (p < 0.05), HDL +20% (p < 0.001), TG-53% (p < 0.001). Acipimox is well tolerated and is useful as a lipid-lowering drug in type IIa, IIb and IV dyslipidemias. Further studies are necessary to clear effects of the drug on renal metabolism and on long term survival of coronary pts.

[Adult non-insulin-dependent diabetic: limitation of articular mobility and soft tissue involvement]

Periarticular involvement and joint mobility were investigated in 100 non insulin dependent diabetic patients, compared to 100 healthy control subjects of similar age and sex. Periarticular involvement was much more common in diabetics (p < 0.01) including limitation of joint mobility (hands) (40% vs 9%), Dupuytren (29% vs 2%), palmar synovitis (59% vs 7%) and capsulitis (16% vs 1%). Diabetic patients with limitation of joint mobility had more neuropathy (80% vs 56%), retinitis proliferans (35% vs 17%) and alterations of the skin of the hands, compared to diabetics without limitation of joint mobility. Diabetes should be investigated in subjects with periarticular manifestations such as those described in this paper. Also, a more advanced stage of diabetes may be suspected in diabetics with such manifestations.

[The effects of a dietary fiber (white lupine bran) in the treatment of non-insulin-dependent diabetes]

We evaluated the effect of dietary fiber from sweet lupine hull (SLH) upon metabolic control in 16 non insulin dependent diabetics (11 males, mean age 52). Body mass index was 23 +/- 2 and non fasting glucose levels were < 200 mg/dl. Following a 2 month control period, patients received SLH, 10 g th 3rd month and 20 g the fourth. Eleven patients received in addition oral hypoglycemic drugs. Intake of crude dietary fiber increased from 4.1 +/- 1.7 to 8.4 +/- 2 and 13.1 +/- 1 g from control to the 3rd and 4th month. Blood glucose increased and cholesterol level decreased in the 3rd month (p < 0.05). During the 4th month, blood glucose decreased to control levels. No changes were observed in body mass, HDL cholesterol, triglycerides, glycosylated Hb and non-fasting glucose and insulin levels in relation to fiber intake. We conclude that dietary fiber intake is low in our patients but a supplement of 10 to 20 g of this particular fiber did not improve metabolic control.