COVID-19 and macular edema: a necessarily blindness?

Graefe's Archive for Clinical and Experimental Ophthalmology -     

Differential role for the striatum and cerebellum in response to novel movements using a motor learning paradigm.

The aim of this pilot study was to examine the role of the striatum and cerebellum in the adaptation to a novel movement within a sequence of practiced movements using a motor learning paradigm. The performance of patients in the early or advanced stages of Parkinson's disease (PD) and of patients with damage to the cerebellum (CE) was compared, respectively to a group of aged and young matched controls on an adapted version of the Mirror-Tracing Test. In this task, subjects were required to trace a series of complex figures in two conditions: (1) a Practiced condition, in which the figures were composed of the juxtaposition of three simple designs that were extensively practiced before; and (2) a Mixed condition in which triads were created by replacing the last simple figure of the triads in the Practiced condition by a new simple figure that had never been traced individually before. Results showed that all clinical groups were slower than controls at tracing the Practiced triads. Most interestingly, however, only patients in the advanced stages of PD showed increased completion time to trace the triads in the Mixed condition. This suggests that a bilateral striatal dysfunction affects the ability to adapt to a novel motion within a sequence of practiced movements. Although exploratory, these results support a functional dissociation between the striatum and cerebellum in acquiring visuomotor skilled behaviors.     

Isozyme variation in Simulium (Edwardsellum) damnosum s.l. (Diptera: Simuliidae) from Kenya

Isozyme variation of the Simulium damnosum sibling species complex was studied by cellulose acetate electrophoresis (CAE) from four Kenyan river systems. Two enzymes, PGM and HK, were diagnostic and differentiated the larvae collected in Western and Nyanza provinces from the larvae collected at Mt. Kenya. Allele frequency differences of the enzyme PGI allowed about 75% separation of the geographically distinct populations.     

Evolutionary aspects of “chloroplast-like” trnN and trnH expression in higher-plant mitochondria

Two identical “chloroplast-like” tRNA^Asn genes, trnN1 and trnN2, have been identified in the potato (Solanum tuberosum) mitochondrial genome. The flanking sequences of trnN1 are unrelated to the corresponding authentic potato chloroplast regions, whilst those of trnN2 are very similar to the chloroplast sequences. The trnN1 copy is present in the mitochondrial genome of various plants whereas the second copy, trnN2, is absent from all the other plant genomes studied so far. Interestingly, both trnN copies are expressed in potato mitochondria. Sequences flanking the chloroplast-like tRNA^His gene (trnH), present as a single copy in the potato mitochondrial DNA, are unrelated to the corresponding chloroplast sequences, whereas chloroplast-derived sequences have been maintained in the vicinity of the maize chloroplast-like mitochondrial trnH gene. However, both the potato and the maize trnH are expressed in mitochondria. Received: 10 April / 1 August 1997     

Neuropathy associated with “benign” anti-myelin-associated glycoprotein IgM gammopathy: Clinical,immunological, neurophysiological pathological findings and response to treatment in 33 cases

We studied 33 patients presenting with a peripheral neuropathy associated with non-malignant anti-myelin-associated glycoprotein (MAG) IgM monoclonal gammopathy (MG) in an attempt to delineate their clinical, immunological, electrophysiological and pathological characteristics; we also reviewed our experience concerning long-term follow-up and therapy. Peripheral neuropathy associated with non-malignant anti-MAG IgM MG was observed mostly in males (sex ratio 7.2), and mean age at onset was 67 years (range 46–81). A predominantly sensory pattern was noted in more than 80% of cases, although some patients were affected by a predominantly motor peripheral neuropathy. Although disease progression was slow in most cases, 45% of patients suffered severe disability, and in 2 cases, the patient's death appeared to stem directly from the neuropathy. The electrophysiological findings were indicative of a demyelinating process in 90% of cases, and electron microscopic examination of nerve biopsy specimens demonstrated widening of the myelin lamellae in more than 95% of cases. Most of our patients showed a disappointing response to steroids and chemotherapy or plasma exchanges. Intravenous immune globulin, evaluated in 17 patients, had a transient, mostly subjective effect in 35% and led to a clear-cut improvement in 24% of cases. We did not observe any correlation between the severity of the clinical picture and the anti-sulphoglucuronyl paragloboside antibody titre; in individual cases, clinical improvement occurred without lowering of IgM levels. Although the severity and the rate of progression may greatly vary from patient to patient, the combination of clinical, electrophysiological and pathological features delineates a characteristic pattern in peripheral neuropathy associated with non-malignant anti-MAG IgM MG.     

Measurement of drug compliance by continuous electronic monitoring: a pilot study in elderly patients discharged from hospital.

OBJECTIVE: A pilot study to assess patient compliance with medication by using a new measurement technique, continuous electronic monitoring. DESIGN: Survey. Compliance monitors were provided to eligible patients at discharge from the hospital to measure drug intake behavior prospectively for a period of 3 weeks. SETTING: Ambulant patient care after discharge from a geriatric hospital, Krankenhaus Bethanien, which is affiliated with the University Clinic, Heidelberg. PATIENTS: A consecutive convenience sample of 18 independently living elderly patients (median age 76 years) completed the study. The patients were on maintenance therapy with cardiac glycosides and/or potassium-sparing diuretics prescribed to be taken once daily. INTERVENTION: The monitoring method provides information about patients' real timing of drug use by continuously recording date and time of openings and closings of the medication containers (monitors). In addition to a standard measure, the percentage of prescribed doses taken, information about regularity of drug use is obtained. RESULTS: Compliance, percentage of prescribed doses taken, was remarkably variable; it ranged from 24% to 100%, 95% CI: 62%-84%. Mean compliance declined from the first to the third week after discharge, 85% vs 69%, 95% CI: 74%-95% and 56%-81%, respectively (P < 0.05). Omissions of doses, the predominant pattern of non-compliance, were observed in 17 of 18 patients. Regularity of dose timing, as defined by the number of interdose intervals within 24 h +/- 15%, varied from 10% to 100%, 95% CI: 46%-76%. CONCLUSIONS: Continuous electronic monitoring revealed highly variable compliance in patients prescribed maintenance therapy. Even with a once-daily regimen, persistent and high compliance cannot be assumed. The monitoring technique may be of great value to research and, possibly, to practical therapeutic management.     

Autosomal dominant centronuclear myopathy]

In a family 6 members in 3 generations were affected by centronuclear myopathy (CNM) of autosomal dominant inheritance. The apparent onset was in the early forties and the disease progressed slowly. Limb weakness was predominant. Strabismus was present in 5 cases and calves hypertrophy in 3. Serum creatinine kinase was always within the normal range. In one case myotonic bursts were found at electromyography. In 2 cases brain stem auditory evoked potential studies demonstrated abnormal prolongation of interpeak latencies I-III and favoured subclinical nervous system involvement. Muscular biopsies showed typical features of centronuclear myopathy with 50 to 80% central nuclei. In two cases immunocytochemical labelling of dystrophin showed staining in the sarcoplasm in favour of an arrest in the morphogenesis of developing myofiber. Others families with autosomal dominant CNM in the literature and also some sporadic adult cases had similar clinical features.