A gene for autosomal recessive limb-girdle muscular dystrophy maps to chromosome 2p

The limb-girdle muscular dystrophies are a clinically and genetically heterogeneous group of disorders. We have studied two large inbred families of different ethnic origin and excluded linkage to LGMD2 on chromosome 15q and SCARMD on chromosome 13. Proceeding to a genomic linkage search, we have now identified linkage to markers D2S134 and D2S136 on chromosome 2p (maximum lod score 3.57 at zero recombination). The phenotype in the two families was similar, with onset in the pelvic girdle musculature in the late teens and usually relatively slow progression. This work identifies a second locus for autosomal recessive limb-girdle muscular dystrophy.

Cell cycle and growth regulation in RAS2 mutant cells of Saccharomyces cerevisiae

Yeast cells carrying ras2 temperature-sensitive mutations undergo a specific arrest in the prereplicative unbudded phase of the cell cycle when they are shifted to non-permissive temperatures. At 36.5 degrees C, in spite of their abnormally large cell size, bulk protein synthesis and accumulation rates are depressed in ras2 temperature-sensitive cells in comparison with isogenic wild type. At the same temperature, total RNA synthesis and accumulation rates are much more inhibited, suggesting that a defective Ras2/cAMP pathway alters the coordination between RNA and protein synthesis rates. The preferential RNA synthesis inhibition is correlated to a specific inhibition of the synthesis of the 35S rRNA precursor. These findings, taken together with the results of previous analyses, are in favour of a control by the cAMP pathway on rRNA biosynthesis.

Sporadic juvenile amyotrophic lateral sclerosis

A case of sporadic amyotrophic lateral sclerosis with onset at 18 years of age and death one year after is reported. Only 8 other cases with such an early onset (and the typical clinical and pathological features of ALS) have been reported in the literature. Resemblances between these cases and adult ALS are pointed out, but since all knowledge about their etiology is lacking, the relationship between them remains unclear.

cAMP-mediated increase in the critical cell size required for the G1 to S transition in Saccharomyces cerevisiae

In Saccharomyces cerevisiae, cyclic AMP is required for cellular growth. In this study we show that cAMP also specifically inhibits the G1-S transition of the S. cerevisiae cell cycle by increasing the critical cell size required at start, the major yeast cell cycle control step. In fact: (a) addition of cAMP delays the time of entering into the S budded phase of small G1 cells, while it is ineffective on large fast-growing cells. (b) If cell growth is strongly depressed, cAMP permanently inhibits cell cycle commitment of cells arrested at the alpha-factor-sensitive step. The cell fraction inhibited by cAMP is inversely correlated with the average cell size of treated populations. (c) The critical protein content (Ps) and the critical cell volume (VB) required for budding in unperturbed exponentially growing yeast populations are largely increased by cAMP. On these bases, we propose a new cAMP role at start.

In vitro interaction between Saccharomyces cerevisiae CDC25 and RAS2 proteins

In Saccharomyces cerevisiae the CDC25 protein is a positive regulator of RAS/cAMP pathway [1-4], enhancing the GDP-releasing rate of RAS2 protein [5]. In this work we have tried to detect a direct interaction between CDC25 and RAS2 gene products. The results indicate that both the whole RAS2 protein and a truncated version that lacks approximately 25 C-terminal residues interact specifically with the CDC25 protein. On the contrary, a derivative of RAS2 that lacks the 112 C-terminal residues as well as the p21TI-ras is not able to bind the CDC25 protein in our assay conditions. The 310 C-terminal aminoacids of CDC25 bind RAS2 while a C-terminus deletion within this aminoacid stretch abolishes the binding. The possible physiological significance of these findings is discussed.

Control of breathing in patients with myasthenia gravis

Control of breathing has seldom been investigated in patients with myasthenia gravis (MG). We evaluated lung volumes and respiratory muscle strength by measuring maximal inspiratory (MIP) and expiratory (MEP) pressures in 12 patients with moderate generalized (IIb) MG before and after an orally administered therapeutic dose (120 mg) of Mestinon, and in 11 age- and sex-matched normal subjects. Breathing pattern, mouth occlusion pressure (P0.1), and surface electromyographic activity of the diaphragm (EMGd) and intercostal (EMGint) muscles were evaluated during both room-air breathing and hypercapnic rebreathing. Before Mestinon, patients exhibited a slight decrease in VC, and normal TLC and FEV1/VC ratio. Compared with the normal control group, patients also exhibited respiratory muscle weakness (marked decrease in MIP and MEP; p less than 0.001 for both), and more rapid and shallower breathing (RSB): lower tidal volume (VT), inspiratory time (TI), expiratory time (TE), and greater respiratory frequency (f); mean inspiratory flow (VT/TI) and P0.1 were slightly supernormal, whereas both EMGd and EMGint were significantly higher in patients. During hypercapnic rebreathing, ventilation (VE) (p less than 0.001), VT (p less than 0.001), VT/TI, (p less than 0.003), P0.1 (p less than 0.003), and EMGd (p less than 0.001) response slopes to increasing PCO2 were found to be lower, whereas EMGint response slope was normal. At 60 mm Hg of PCO2 in the two groups the difference in terms of breathing pattern, P0.1, and EMGd were similar to that observed during room-air breathing. After Mestinon, VC (p less than 0.005), MIP (p less than 0.02), and MEP (p less than 0.01) significantly increased, whereas spontaneous breathing remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

On coenzyme Q orientation in membranes: a linear dichroism study of ubiquinones in a model bilayer

A general approach is developed to interpret linear dichroism (LD) spectra of ubiquinones (Qn) in host bilayers. Information is reported in terms of guest-host mutual orientation and localization. The overall orientational anisotropy of guest ubiquinone molecules is described by a basic set of limiting orientation/localization modes. Assignments of the UV transitions of the ubiquinone chromophore were obtained by the liquid crystal-linear dichroism technique and molecular orbital (CNDO/S) calculations. The LD spectra of Qn in the bilayers provided by the lyotropic nematic mesophase exhibited by water solutions of potassium laurate and decanol were interpreted on the basis of the above assignments. The resulting experimental evidence showed a multisite distribution in the host bilayer for the aromatic heads of all the investigated Qn derivatives except Q0. The orientational distribution suggested by the LD spectra fits the solubilization model recently proposed by G. Lenaz [J. Membrane Biol. (1988) 104:193-209] for ubiquinone in lipid membranes. Within this model Qn molecules are located in the midplane and their headgroups oscillate transversally across the membrane. Q0 instead has a single site location, close to the polar bilayer interface. Experimental evidence that the headgroup carbonyls tend to grasp the polar interface of the host bilayer was also obtained. Orientation and location distributions of Qn guest molecules are therefore likely to result from the tendency of their aromatic heads to grasp the polar heads of the host bilayer and from the concurrent tendency of their chains to settle into the hydrocarbon host interior.

Salpingoscopy: systematic use in diagnostic laparoscopy

OBJECTIVE

To evaluate the importance of salpingoscopy together with laparoscopy in the diagnosis of tubal pathology.

DESIGN

Salpingoscopy was performed as a complementary method in patients who were subjected to diagnostic laparoscopy. The relationship between the salpingoscopy and (1) the patient's previous history of tubal disease and (2) laparoscopic diagnoses was evaluated.

SETTING

Private patients referred to the Instituto de Fertilidad, Buenos Aires.

PATIENTS, PARTICIPANTS

Forty-two patients undergoing a diagnostic laparoscopy during the evaluation of their fertility or as a follow-up of previous therapy.

MAIN OUTCOME MEASURE(S)

Salpingoscopy was performed, using a colpomicrohysteroscope. We evaluated alterations in major and minor folds and their vascularization, the presence of microadhesions, and cellular nuclei dyed with methylene blue in the tubal lumen.

RESULTS

Fifty percent of the patients who had no previous history of tubal disease presented with endosalpingeal alterations, and in 37% of the normal laparoscopies the salpinx had unilateral or bilateral salpingoscopic abnormalities.

CONCLUSIONS

Salpingoscopy is a useful method to evaluate oviducts, before assuming their normality, and consideration of these women for assisted reproductive technology.

[Biological dyschronism and circadian organization of serotonin, noradrenaline and platelet aggregation]

The importance of the environment and the increasing use of laboratory tests to study recurrent and debilitating disease have prompted studies regarding underlying biological condition with the aim of identifying suitable biological and therapeutic strategies in terms of their physiopathology. The aim of this study was to search for physiological overlaps between the circadian and serotonin (5HT), noradrenaline (NA) and platelet activity in regulating the peripheral microcirculation in a group of healthy subjects and a group of patients with recurrent and debilitating disease.

Limb girdle muscular dystrophy with autosomal dominant inheritance

We describe a patient suffering from limb-girdle muscular dystrophy with autosomal dominant inheritance proved by the presence of other similar cases in both sexes scattered over 4 generations of his family tree. In all patients the symptoms appeared in adult age and pelvi-femoral preceded scapulo-humeral involvement. Clinical expressivity has been variable, but rather benign without any reduction in life expectancy. Myopathic changes with vacuoles were present in muscle on light and electron microscopic examination. In the literature we found at least another 5 genealogies with autosomal dominant LGMD which had similar clinical and pathological features to those of our patient.

Interactions of nucleic acids with distamycins. The drug monomeric chromophore

A study of the monomeric chromophore of the oligopeptides netropsin (1), distamycin III (2), and distamycin V (3) by polarization spectroscopy techniques and molecular orbital calculations is reported. Linear dichroism spectra of the monomeric model compounds 1-methyl-2(ethylcarbamoyl)-4-acetamido-pyrrole (4) and 1-methyl-2(ethylcarbamoyl)-pyrrole (5) dissolved and oriented in lyotropic and thermotropic liquid crystals provide, together with the magnetic CD spectra, experimental checks of the theoretical calculations. The polarization directions of the investigated transition obtained by these means in this study allow us to build up in the following paper the exciton states of (1)-(3) and these provide a stereochemical interpretation of the flow linear dichroism spectra of the complexes of DNA with (2) and (3).

Linear dichroism studies of the complexes between CT-DNA and distamycins

The study of the monomeric chromophore of the distamycins reported in Ref. 1 was used here to build up a description of the electronic states of the whole oligopeptide by the exciton theory. Liquid crystal-linear dichroism (LC-LD) spectra of the distamycins were recorded by using as orienting solvents both thermotropic and lyotropic mesomorphic media. The agreement between the LD spectra and the polarization assignments by the exciton treatment is satisfactory. On this basis the flow-LD spectra of the complex between distamycin V and DNA was interpreted in terms of the preferred relative orientations of the guest and host molecules. A single site location of the distamycin within the minor groove does not perfectly match the experimental order parameters. This orientational distribution function could be too simple to explain the experimental data. It may therefore be assumed that a small fraction of the guest molecules are preferentially aligned more parallel to the host chain axis than the minor groove. Alternatively, and probably more likely, the partial mismatch of the experimental data with the minor groove location may be seen as a manifestation of the well-known stiffening and bending effects at the binding sites, which have already been observed by other techniques.

Evidence for a human mitotic mutant with pleiotropic effect

Male and female sibs born to third-cousin parents presented with mental retardation, microcephaly, short stature, juvenile onset limb-girdle muscular dystrophy and multiple chromosome mosaicism in lymphocytes and fibroblasts. Different aneuploidies (mostly trisomies) were found in 15-20% of the cells and trisomies for chromosome 8 and chromosome 7 predominated in lymphocytes and fibroblasts respectively, while monosomies were rare. Increased cellular death due to aneuploidy could explain symptoms such as mental and growth retardation and microcephaly. This could be an instance of an autosomal recessive mitotic mutant, possibly affecting a protein simultaneously involved in spindle apparatus and muscle function.

Plasma-exchange in myasthenia gravis: a study in 20 patients

Twenty patients with myasthenia gravis (MG) of generalized 2A and 2B types according to the Ossermann classification were treated with a course of nine plasma exchanges (PE) every two days. Before starting of the course, at the fourth exchange, and at the end of the course, the muscle balance was assessed following a special protocol. Other functions, such as respiratory function, stapedial reflex, phonation, and electro-oculographic activity were assessed and a Desmedt test was done. Three patients showed complete remission of symptoms, 8 showed good improvement and 6 mild improvement. Three showed no improvement. In total 85% of patients gained from PE. The onset of improvement was rapid in all patients but in some it lasted only a short time while in others it persisted for several weeks and even months, without the need for immunosuppressive therapy.

Electrophysiological studies of the visual system in myotonic dystrophy

Ocular signs and electroretinal alterations frequently occur in Myotonic Dystrophy (MD). Surprisingly few reports describe VEP abnormalities for this syndrome. Since the evaluation of cortical visual responses is linked to an understanding of preceding retinal changes, we conducted a systematic study of the visual system including ophthalmological and electrophysiological (EOG, ERG, PERG, VEP) investigation in 14 confirmed myotonic patients. The various tests revealed consistent abnormalities, the most frequent of these being PERG and VEP changes. These alterations seemed to occur independently of one another, suggesting impaired function at different levels of visual pathway. A generalized defect of cell membrane has recently been proposed as etiopathogenesis of typical EMG and systemic features of the disease. Such membrane dysfunction might account for the early and marked abnormalities in electrophysiological tests, even in the absence of neuro-ophthalmological changes.

[Role and possibilities of compensation filters in lateral decubitus radiographs in opaque enemas]

A wedge-shaped plexiglass compensation filter for use in lateral decubitus radiographs of double contrast barium enema examinations has been designed. This filter, which has been used since February 1985, was compared with a second plexiglass filter, made by E-Z-EM. Voltage and amperage were kept contrast. Two different experiments were conducted in order to demonstrate the benefits of routine use of this compensation filter. First, the changes in skin dose were assessed using an ionization chamber on a phantom. Secondly, three radiologists examined a series of 80 consecutive barium enemas without knowing which had been performed using the new filter. Out of the 70 examinations they considered excellent, as many as 45 had been performed with the new filter. Personal experience and the studies described show that the use of a compensation filter improves the accuracy and thus the diagnostic quality of the examinations as it enhances the detail of the anatomic structure of the colon; moreover the filter reduces skin exposure by up to 73.1% (EZ-E-EM filter 47.3%) and, at the same time, less radiographic films are needed. Routine use of a plexiglass compensation filter in lateral decubitus radiographs while performing a double contrast barium enema examination, is strongly recommended especially in obese patients.

Plasma-exchange in idiopathic radiculopolyneuropathies: a study in 62 patients

The effectiveness of plasma exchange (PE) in the treatment of acute and chronic idiopathic radioculopolyneuropathies (IR) is discussed on the basis of the literature and personal data. Results of controlled trials by Swedish, French and North American groups are favourable to the use of PE in acute forms, whereas one English group found no significant differences between treated patients and controls. Dick et al. (1986) reported significant improvement also in patients with chronic forms after PE. Personal data from a non-controlled series of 62 acute and chronic IR and from a trial group of 12 acute patients and 12 controls indicated that PE--though helpful in Guillain-Barré syndrome--was not so useful in chronic forms.

Becker and limb-girdle muscular dystrophy associated with pituitary dwarfism

In 1981 a report appeared of a patient with Duchenne muscular dystrophy associated with dwarfism caused by growth hormone deficiency, in whom the muscular disease was unusually benign. The authors suggested that the benign course might be related to the growth hormone deficiency and dwarfism. Other authors later supported this idea, having observed that in dystrophic mice and hamsters with congenital and experimentally induced pituitary dwarfism, respectively, pathological expressions of the dystrophy were markedly reduced. In this paper one case of Becker and one of limb-girdle dystrophy, each associated with short stature and growth hormone deficiency are described. In these cases the disease did not have a particularly benign course. It is concluded that caution is necessary, at least in certain cases, before an association between reduced muscular growth and the dystrophic process can be assumed.

[A biological marker in drug dependence: microcirculatory homeostasis]

In 25 heroin addicts examined an initial alteration in microcirculatory homeostasis was found ond held to be responsible for the addiction. As in other cases it is thought possible to use the chronobiological course of haemodynamic balance and imbalance as a biological marker for prevention and treatment.

Sarcoplasmic reticulum Ca2+-ATPase and acylphosphatase activities in muscle biopsies from patients with Duchenne muscular dystrophy

Sarcoplasmic reticulum Ca2+-ATPase, acylphosphatase and other soluble enzymes (creatine kinase, lactate dehydrogenase, aldolase and pyruvate kinase) were assayed in muscle biopsies from patients affected by Duchenne muscular dystrophy (DMD) and from normal controls. Specific activities of all the soluble enzymes were decreased in dystrophic muscle, acylphosphatase exhibiting the most marked and significant decrease comparable to that of creatine kinase, in spite of a moderate increase in serum levels. Also, Ca2+-ATPase, particularly the calcium-dependent activity, was decreased in dystrophic muscle. A positive correlation, higher than with the other soluble enzymes, was obtained between acylphosphatase specific activity and the percentage of Ca2+-activation of Ca2+-ATPase. These findings: suggest an impairment of microsomal calcium uptake which could be, at least in part, responsible for sarcoplasmic calcium accumulation observed in DMD; do not disagree with an hypothesized role of acylphosphatase in intracellular calcium homeostasis, consistent with the enzyme's demonstrated hydrolytic activity on the phosphorylated intermediate of Ca2+-ATPase.

[Desynchronization of serotonin, hemodynamic equilibrium and the recurrence of migraine crises]

Haemodynamic balance and the circadian rhythm of plasmatic 5HT were studied in 15 migraine sufferers (common and classic). Haemodynamic imbalance and a clear desynchronisation of the 5HT acrophase was discovered. It is thought that these two elements are correlated and represent a key to the recurrence of migraine attacks.

[Desynchronization of noradrenaline and hemodynamic equilibrium in migraine subjects]

Fifteen migraine sufferers and a control group were checked for the circadian rhythm of urinary catecholamine and VMA excretion. These data were compared with the typical variations in haemodynamic balance already encountered in migraine sufferers. It is felt that this connection is an essential element in the pathogenesis of headaches.

[Chronobiology of dynamic equilibrium and recurrence of migraine crises]

Haemodynamic balance was assessed in relation to platelet-vessel homeostasis in the microcirculation in a group of 15 migraine sufferers and 15 healthy subjects. The results support the hypothesis of a relationship between the typical recurrence of migraine attacks and the chronobiological performance of the haemodynamic balance.

[Chronobiological evaluation of hemodynamic equilibrium in the developmental years]

Knowledge of the incidence of haemodynamic imbalance syndromes and consequent pathologies in growing children at various ages may be a useful aid to the preventive measures that make for effective treatment of the organs involved in the psychological and physical development of school children. The oscillation between haemodynamic balance and imbalance was monitored in 849 subjects aged 3-18 on the basis of periods of absence relatable to the biorhytmic cycle of each pupil within the daily and seasonable rhythm. The survey identifies the instruments that facilitate natural haemodynamic balance and reduce desynchronising stimuli.

Study of endocrine function in myotonic dystrophy

Endocrine function was studied in 12 patients, 7 men and 5 women, with myotonic dystrophy (MD). Growth hormone (GH) was within normal limits in all the patients and there was no response to arginine stimulation. Prolactin (PRL) was above normal in only 2 cases (one man and one woman) and the response to TRH was below normal in 2 patients and slightly above in one. The GnRH test yielded a reduced LH response in 4 of the 7 men and none at all in the 4 women in whom it was done. The FSH response was below normal in only one of the 7 men and in 3 out of 4 women. The testosterone assay after HCG stimulation was borderline high in 2 out of 6 men and below normal in one. The level of thyroid hormones (T3, T4, FTI, TSH) was normal in all patients except one, whose FTI and T4 level were below normal. In the TRH test TSH was raised in only one of the 6 patients tested. The circadian rhythm of cortisol was absent in 3 out of 10 patients and 3 out of 8 patients showed no response to ACTH stimulation. The results of the study suggest that endocrine alterations are fairly frequent in MD but that they are neither specific nor correlated with disease severity or duration.

Ophthalmoplegia plus, an electro-oculographic study

To find out whether the central structures governing conjugate eye movements are affected in ophthalmoplegia plus (OP), we conducted an electro-oculographic study in 6 patients suffering from OP with varying degrees of extraocular involvement and with mitochondrial changes in the skeletal musculature. All the patients presented alterations of the smooth pursuit and saccadic movements, of optokinetic nystagmus as well as of the vestibular reflexes and of visuovestibular interaction, thus confirming impairment of the central oculomotor structures and particularly of those of the archicerebellum and brainstem. These data suggest a supranuclear component in the pathogenesis of ophthalmoplegia and are in accord with the findings of brainstem spongiosis in OP, which in turn seem to express a multisystem pathological state of the mitochondria.

[Chronobiologic resolution of disabling pathologies in shift workers]

The annual sequence of sickness leaves was studied in 162 industrial workers with a high absenteeism level. An investigation of the swings in haemodynamic balance, and imbalances linked to alternations in vessel constriction and dilation throughout the biorhythmic cycle influenced by the alternation of night and day, hot and cold seasons, showed that each period of sick leave coincided with each period of haemodynamic balance caused by particular shifts. It was thus possible to identify groups of workers with syndromic sub groups whose performance was affected by night work and particular seasons. For optimal shift-worker deployment it is therefore suggested that workers should be assigned to shifts to which they are biologically suited.

Plasma exchange in myasthenia gravis

Results obtained with P.E. therapy on 19 myasthenic patients are reported. 15 of them improved during treatment and 4 remained unchanged. We believe P.E. is an useful therapy in M.G. because it produces a rapid improvement in most patients.

Plasma exchange in radiculopolyneuropathies

The AA. report the results obtained with Plasma Exchange (P.E.) therapy on 24 cases of polyradiculoneuritis; eleven patients had typical Guillain-Barré Syndrome (G.B.S.) ten suffered from a chronic progressive form and three were affected by a relapsing form. The acute patients were selected according to criteria established by the NNCDS Committee (1978) while guidelines laid down by Pineas & Load (1978) were followed in choosing chronic cases. Patients with G.B.S. had four sessions of P.E. at intervals of one or two days while those with chronic forms of polyradiculoneuritis had a total of 6 sessions spaced one to three days apart. P.E. produced no apparent change in chronic progressive patients but two out of three cases with the chronic relapsing form showed rapid and steady improvement resulting in complete cure within a few months. Nine of the eleven G.B.S. patients showed after only one or two sessions a clear and rapid improvement which led to a complete cure within a matter of weeks. The remaining 2 cases showed only partial improvement at first and remained stationary thereafter. The findings confirm the usefulness of P.E. in acute and chronic relapsing radiculopolyneuritis. However, potential side effects and the procedure's high cost suggest that its use should be limited to carefully selected cases, and in particular to those involving respiratory disorders.

Plasma Exchange in Myasthenia Gravis

Results obtained with P.E. therapy on 19 myasthenic patients are reported. 15 of them improved during treatment and 4 remained unchanged. We believe P.E. is an useful therapy in M.G. because it produces a rapid improvement in most patients.