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Biomedical subjects

R Spiegel

Publications and source records attributed to R Spiegel.

At least 19 recordsLinked to original sources
PubMed1992

[Molecular genetics diagnosis of Steinert's myotonic dystrophy].

Myotonic dystrophy (DM) is the most common neuromuscular disease with adult onset (incidence 1 in 8000). The biochemical basis of this autosomal dominantly inherited disease is still unknown. The most striking features are myotonia and progressive muscular wasting. There is high variability of disease severity in patients from different families, but also within the same family. For practical reasons three subtypes can be defined: The classical adult onset form of the disease, a mild form with late onset and/or very moderate symptoms, eg. cataracts only, and the most severe congenital form which is transmitted by affected females. Furthermore, the progression of DM in affected families may exhibit an increase in the severity of the disease in successive generations. This observation is called anticipation. Very recently the DM gene has been cloned and an unstable DNA sequence specific for the disease has been characterized. Detection of an enlarged DNA fragment due to the expansion of a trinucleotide (CTG) repeat within the DM gene can be used for direct DNA diagnosis in affected individuals and persons at risk. Furthermore, there is a strong correlation between the length of fragment expansion and the degree of disease severity in gene carriers. We report here our preliminary results of the investigation of over 70 patients and demonstrate the clinical usefulness of this new method by the findings in three families.

Adult↗
PubMed1992

Meiotic stability and genotype-phenotype correlation of the trinucleotide repeat in X-linked spinal and bulbar muscular atrophy.

Expansion of the trinucleotide repeat (CAG)n in the first exon of the androgen receptor gene is associated with a rare motor neuron disorder, X-linked spinal and bulbar muscular atrophy. We have found that expanded (CAG)n alleles undergo alteration in length when transmitted from parent to offspring. Of 45 meioses examined, 12 (27%) demonstrated a change in CAG repeat number. Both expansions and contractions were observed, although their magnitude was small. There was a greater rate of instability in male meiosis than in female meiosis. We also found evidence for a correlation between disease severity and CAG repeat length, but other factors seem to contribute to the phenotypic variability in this disorder.

Base Sequence↗
PubMed1992

Prenatal prediction of Werdnig-Hoffmann disease using linked polymorphic DNA probes.

Werdnig-Hoffmann disease is a common autosomal recessive neuromuscular disorder that results in paralysis and death. No treatment to prevent this disease or to alter its unremitting course has been found. Recently, linkage analysis with cloned DNA probes has shown that the mutation causing Werdnig-Hoffmann disease is located on chromosome 5q12-q14. We performed genetic analysis for the prenatal diagnosis of Werdnig-Hoffmann disease in seven at risk families. Two fetuses were diagnosed as being affected and the remainder as unaffected, and this was confirmed after birth. This study shows that prenatal diagnosis of Werdnig-Hoffmann disease has become feasible.

Chromosomes, Human, Pair 5↗
PubMed1992

First record of breeding populations of Aedes albopictus in continental Africa: implications for arboviral transmission.

Eggs of Aedes albopictus were collected in oviposition cups from 3 forested areas of Delta State in south-central Nigeria during September 1991 as part of a post-yellow fever outbreak investigation. These eggs were shipped to the Centers for Disease Control in Colorado, where they were reared to the adult stage and identified. This is the first record of breeding populations of Ae. albopictus in continental Africa. Other taxa reared from the same oviposition cups included Ae. aegypti, Ae. apicoargenteus, Ae. africanus, Ae. lilii and Ae. simpsoni subgroup. The introduction and establishment of Ae. albopictus in Africa may have important implications for transmission of indigenous arboviruses.

Aedes↗
PubMed1991

[Neurofibromatosis Type 1: genetic studies with DNA markers in 38 families].

To establish preclinical DNA-diagnosis of neurofibromatosis type 1 (NF1) in familial cases we have investigated 38 families segregating for the disease. The families were tested with 6 polymorphic DNA markers from the chromosome region 17p11.1-q11.2. Two-thirds of the families were informative for flanking markers. An informative situation was achieved for 33 out of 40 individuals at risk (i.e. first degree relatives): 30 cases were diagnosed as noncarriers of the mutated gene, and three clinically normal individuals (including an adult and two children aged three and six respectively) were found to carry the risk haplotype. The remaining 7 persons at risk could not be typed unequivocally due to non-informative markers or recombination events. In 5 families with healthy grandparents the origin of the mutation could be traced back to the grandfather's germ cells. Despite the recent cloning and initial characterization of parts of NF1 gene, studies using linked and eventually intragenic DNA markers will continue to be of great value for genetic counselling. Such analyses allow highly accurate preclinical and prenatal diagnosis in close relatives of familial cases.

Adolescent↗
PubMed1991

Direct access to serum macromolecules by intraerythrocytic malaria parasites.

Trafficking pathways in malaria-infected erythrocytes are complex because the internal parasite is separated from the serum by the erythrocyte and parasitophorous vacuolar membranes. Intraerythrocytic Plasmodium falciparum parasites can endocytose dextrans, protein A and an IgG2a antibody. Here we show that these macromolecules do not cross the erythrocyte or parasitophorous vacuolar membranes, but rather gain direct access to the aqueous space surrounding the parasite through a parasitophorous duct. Evidence for this structure includes visualization of membranes that are continuous between the parasitophorous vacuolar and erythrocyte membranes, and surface labelling of the parasite with fluorescent macromolecules under conditions that block endocytosis. The parasite can internalize by fluid-phase endocytosis macromolecules from the aqueous compartment surrounding it. Thus, surface antigens on trophozoites and schizonts should be considered as targets for antibody-directed parasiticidal agents.

Animals↗
PubMed1991

A new behavioral assessment scale for geriatric out- and in-patients: the NOSGER (Nurses' Observation Scale for Geriatric Patients).

Although a great number of psychometric tests and rating scales for the assessment of psychogeriatric patients is available, there is still an urgent need, in research and practice, for a clinical rating instrument that meets the following main requirements: (1) applicable to institutionalized and community patients and covering a wide range of behavioral pathology; (2) acceptable and easy to use for professionals and lay persons alike; (3) covering a wide range of behavior relevant to daily functioning but independent of sex or social status of the individual assessed. The NOSGER contains 30 items of behavior, each rated on a 5-point scale according to frequency of occurrence. Item scores are summarized into 6 Dimension scores (memory, instrumental activities of daily life, self-care, mood, social behavior, and disturbing behavior) which are clinically relevant in dementia, depression, and other psychiatric disorders of old age. Validation studies with a preliminary version of the NOSGER indicated good acceptance of the scale, high inter-rater and test-retest reliability, and high correlations of all NOSGER Dimension scores with results of a variety of established assessment instruments. The NOSGER is currently being used in a number of European and North American centers and should turn out to be a useful instrument for longitudinal studies in psychogeriatrics.

Activities of Daily Living↗
PubMed1989

The cholinergic rapid eye movement sleep induction test with RS-86. State or trait marker of depression?

Rapid eye movement (REM) sleep disinhibition at the beginning of the night is one of the most frequently described biologic abnormalities in depression. As REM sleep in animals and humans seems to be facilitated by cholinergic neuronal activity, it has been postulated that REM sleep disinhibition in depression is a consequence of cholinergic neuronal overactivity. The current study with the newly available cholinergic agonist RS-86, which is orally active, has a half-life of six to eight hours, and exhibits only minor peripheral side effects, supports this assumption. The application of this compound before sleep led to a significantly faster induction of REM sleep at the beginning of the night in patients with major depressive disorders compared with healthy subjects and patients with other nondepressive psychiatric diseases, such as eating disorders. Whereas 14 of 16 depressed patients displayed sleep-onset REM periods after the administration of RS-86, this happened only in three of the 16 healthy controls and in one of the 20 patients with other diagnoses. The increased susceptibility of REM sleep to cholinergic stimulation was limited to the state of depression and was not observed in a group of remitted depressed patients.

Adolescent↗
PubMed1989

Muscarinic agonists for senile dementia: past experience and future trends.

Clinical experience with muscarinic agonists in the symptomatic treatment of Alzheimer's disease includes studies of the effects of pilocarpine, arecoline, bethanechol, oxotremorine and RS 86. Although the results are somewhat conflicting, there is evidence that a subgroup of patients may respond with an improvement of cognitive and/or behavioural function. The existing agents tend to induce adverse effects due to the stimulation of peripheral muscarinic receptors. Furthermore they reduce (at least in vitro) acetylcholine release by an action on presynaptic receptors. Strategies to overcome these problems include the development of potent agonists with high blood-brain barrier penetration, the search for agents selective for muscarinic receptor subtypes (using cloned receptors as tools) and the identification of agents acting as presynaptic receptor antagonists, to increase acetylcholine release.

Alzheimer Disease↗
PubMed1987

[Acral rewarming. I: "Normal data" of a healthy adult population].

The acral rewarming test was investigated in 285 healthy subjects (mean age: 44.1; 20-71) to establish "normal" or reference values as a basis for interpreting patient data. The study was disposed in a manner to look also for possible diurnal and seasonal variations of the rewarming parameters. Healthy controls show a considerable interindividual variability in the speed and the pattern of acral rewarming, with a striking bimodal distribution of the individual values. This variability is mainly due to the factors "season" and "gender", while "age" and "daytime" are more related to basal finger temperature as to the rate of rewarming. According to these findings seasonal variations must necessarily be included in the definition of normal reference values of the rewarming test. In the healthy subjects neither personality characteristics (Freiburger personality inventory) nor the individual's psycho-social situation (Life Event questionnaire) and "depressivity" (Beck inventory) correlate with rewarming parameters. However, momentary "fatigue" (Visual Analogue Scale) correlates negatively and the sum of "somatic complaints" positively with acral rewarming time. The issue of variability in normative data is discussed with reference to clinical applications of the rewarming test in part II.

Adult↗
PubMed1987

[Acral rewarming. II: Comparison of healthy probands and depressed patients].

The effect of local cooling on acral rewarming function was measured in healthy subjects and depressed patients. Although group comparison showed that acral rewarming is significantly slower in depressed patients, this parameter cannot be considered as specific for thermoregulatory disturbances in depression since there is marked overlap between groups. Comparison of the annual course was more informative. Annual variations in acral rewarming rate with sex specific differences were found in both groups. However, the variation with time of year was of greater amplitude in depressed patients. Furthermore, in the patient group an annual rhythm was present even in basal finger temperature. Significant March and October troughs in rewarming efficiency after local cooling were found in women (both groups). The greater proportion of depressed women, and the higher spring and autumn incidence of affective illness, may thus have a physiological correlate. The results are discussed in view of the relevance of the acral rewarming test in psychiatric practice and research, the seasonal changes in thermoregulatory measures in the light of a chronobiological approach to depression.

Adult↗
PubMed1979

[A new geriatric battery test].

Both the clinical and the experimental field of geriatrics are in need of an instrument to test the cognitive abilities of people aged 60 and above. By means of a pre-test of the new geriatric test-battery, those abilities, which generally decrease with age, are tested first in order to obtain a testability rating for a particular patient. The geriatric test-battery, which is based on a theory of a 4 dimensional intelligence clearly delineating the differential development of specific cognitive abilities into old age, allows a precise, differentiated assessment of the cognitive abilities of the elderly. Considering the particular characteristics of the old person, the geriatric test-battery was given a new form which minimizes the feeling of being threatened by the test and at the same time maximizes motivation. The geriatric test-battery is pleasant for both the patient and the tester, it is simple to administer, can easily be given to physically impaired or bedridden patients, and is not time consuming.

Aged↗
PubMed1979

Hypnotic efficacy of temazepam: a long-term sleep laboratory evaluation.

1 Temazepam was evaluated in a strictly defined insomniac patient population under sleep laboratory conditions. Two protocols were used: a short-term (26-night) and a long-term (54-night) protocol evaluated the efficacy of the drug administered at night at 15 mg (short-term study) and 30 mg (long-term study), respectively. 2 Temazepam seemed to be both safe and effective at doses of 15 and 30 mg with up to 5 weeks of ingestion. 3 Suppression of slow wave sleep was observed at the high dose, but no suppression of REM sleep, found in studies with other benzodiazepines, was noted. 4 No evidence was found for development of tolerance or rebound effects.

Adult↗
PubMed1978

Longitudinal mixing in pulmonary airways--normal subjects respiring at a constant flow.

We have measured the impulse response of helium and sulfur hexafluoride in the airways of five normal human subjects at a respiratory flow of 400 ml/s. The longitudinal mixing of the inert gases was characterized by the increased volume variance of the expired concentration response. This parameter was measured over the largest possible range of airway penetrations, 30-290 ml. Employing a symmetrical model of the airway geometry, we have computed the values of a mean mixing coefficient from the volume variance data. This mixing coefficient is largest in the large airways and decreases rapidly with increasing penetration; it may be as much as 4,000 times greater than the molecular diffusivity; and it is relatively independent of the inert gas tested, at least up to an airway penetration of 180 ml. These observations are consistent with several preivously proposed mixing mechanisms including axial streaming, turbulent dispersion, and mixing by geometric asymmetry. However, the latter observation appears to rule out the importance of laminar dispersion since mixing by this mechanism is inversely dependent on the molecular diffusivity.

Humans↗