The distance shortening phenomenon or the lazy arm sign as a subtle pyramidal sign.
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Biomedical subjects
Publications and source records attributed to C Klein.
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Patients with multiple system atrophy (MSA) often have cold, dusky, violaceous hands, with poor circulatory return after blanching by pressure. We therefore compared hand skin temperature in nine age-matched subjects with probable MSA, 10 with idiopathic Parkinson's disease (PD), and 10 healthy controls both at rest and following a standard cooling procedure. Baseline skin temperature in the MSA group was significantly lower than in both the PD and control groups, and four of the nine MSA patients were colder at baseline than the coldest control value. After cooling, the MSA group also showed a significantly greater reduction in skin temperature than the PD group. The rate of skin temperature recovery did not differ between the three groups, although the MSA group required more time to return completely to their baseline temperature. Changes in skin colour or temperature are easily detected, and suggest a defect in neurovascular control of distal extremities. The "cold hands sign" is another clinical "red flag" that helps to raise the suspicion of MSA.
Stride parameters were established in 17 patients with idiopathic Parkinson's disease (PD; mean age 68.8 yrs.; Hoehn-Yahr stages 2 and 3) and in 33 healthy age-matched controls. Free-walking speed was lower in PD as were stride length and cadence. Impaired locomotor synergies in PD were reflected by a higher coefficient of variation of stride length; step width and its coefficient of variation (the latter related to postural imbalance in locomotion) were not changed. No stride parameter correlated with any total score of either the Hoehn-Yahr Scale, the Unified Parkinson's Disease Rating Scale Motor Examination ("UPDRS-III"), the Columbia Rating Scale (CURS) or the Webster Rating Scale. Stride length correlated with a CURS-Bradykinesia-Score, whereas gait velocity correlated with UPDRS-III-Axial-Motor-Score and with the CURS-Bradykinesia-Score. Hypokinesia of gait in moderately disabled PD patients is best assessed by combined analysis of stride parameters and locomotion-related subscores from conventional rating scales.
Grave's disease is often associated with various symptoms summarized as endocrine orbitopathy. A surgical procedure is presented which reduces the exophthalmos by approximately 4.5 mm by resecting the caudal and lateral orbital wall through a subciliar incision. The surgical intervention regularly leads to an amelioration of the functional symptoms of endocrine orbitopathy, such as diplopia, corneal exposure and lid irregularities. In one case an acute reduction of vision on both eyes significantly ameliorated immediately after surgery. The operation described also improves the aesthetic appearance of the patients, who often suffer psychologic impairments associated with Grave's disease.
Madelung-Launois-Bensaude lipomatosis is a rare disease characterized by an enormous accumulation of fat, mainly in the region of the neck. A case is presented to illustrate the course of the disease and its clinical features. In particular, the necessity for a bilateral conservative neck dissection is emphasized to avoid early recurrence.
In a hospital-based case-control study 29 patients with idiopathic Parkinson's disease (PD) and visual hallucinations (VH) were compared with 58 PD patients matched for age and disease duration, but without VH. VH patients had more frequently sleep disturbances and dementia, higher PD-related disability (Schwab-England scale), and took selegiline more frequently as an anti-Parkinsonian drug. The patient groups did not differ in age at PD onset, Webster score, treatment duration, dosage of any anti-Parkinsonian drug, frequency of levodopa-associated movement disorders, or measures on brain CT. After a median follow-up period of 27 months more VH patients had developed wearing-off and freezing phenomena, while their scores in the Mini Mental State Examination were lower. Nursing home placement during the follow-up period was associated with higher PD-related disability in VH patients.
In 29 patients, the intraoral defect after excision of an oral squamous cell carcinoma was repaired with an arterialised venous forearm flap. In all cases, a flap of skin and fat with a superficial vein passing through it was raised from the flexor surface of the right forearm. After the flap had been sutured into the intraoral defect, the original distal end of the vein was anastomosed to an artery and the original proximal end to a vein. Fifteen (52%) of the flaps survived completely, six (21%) had superficial epithelial loss or some marginal necrosis and eight (27%) became completely necrotic. Areas of partial loss developed slowly and formed stable granulation tissue. The flap donor sites were either closed primarily (n = 20) or were covered with a split thickness skin graft (n = 9). There were no functional problems of the donor forearms. These results contrast with the high success rates achieved with orthodox free radial forearm flaps. Further research into venous flaps is essential.
Previous studies using the delayed-matching-to-sample paradigm with visual stimuli reliably induced a postimperative negative variation (PINV) in both schizophrenic patients and healthy controls. The PINV was found to be: (a) larger in schizophrenic patients than controls; (b) larger under conditions of ambiguous as compared to clear matching conditions; and (c) larger over right-hemispheric, fronto-temporal regions in controls, while a less asymmetrical distribution with a tendency for left-frontal predominance occurred in schizophrenic patients. The present study examined to what extent the development and scalp distribution of the PINV were modality-specific by applying the delayed-matching-to-sample design using auditory stimuli. Furthermore, the neurophysiological state during anticipatory negativity (CNV) and PINV was examined by presenting acoustic probe stimuli (one per trial on 50% of the trials) during baseline, CNV or PINV interval. Event-related slow and probe-evoked potentials were recorded in 13 patients with a chronic schizophrenic disorder (DSM-III-R) and 13 healthy control Ss from 15 electrode sites including midline and two sagittal rows over each hemisphere. Comparable group differences and effects of ambiguity on PINV amplitudes were found for both modalities, visual and auditory. The auditory stimuli produced a fronto-central distribution of the PINV in both groups. The probe-evoked vertexpotential was smaller in patients compared to controls, but exhibited comparable modulation with the largest amplitude during the CNV in both groups. Results suggest modality-non-specific cognitive determinants of the PINV. However, stimulus modality did affect the scalp distribution of the PINV. Probe-evoked responses point to different functional meaning of negativities prior to (CNV) and following (PINV) task-relevant stimuli.
Metaphase nucleolar organizer regions (NORs), one of four types of chromosome bands, are located on human acrocentric chromosomes. They contain r-chromatin, i.e., ribosomal genes complexed with proteins such as upstream binding factor and RNA polymerase I, which are argyrophilic NOR proteins. Immunocytochemical and cytochemical labelings of these proteins were used to reveal r-chromatin in situ and to investigate its spatial organization within NORs by confocal microscopy and by electron tomography. For each labeling, confocal microscopy revealed small and large double-spotted NORs and crescent-shaped NORs. Their internal three-dimensional (3D) organization was studied by using electron tomography on specifically silver-stained NORs. The 3D reconstructions allow us to conclude that the argyrophilic NOR proteins are grouped as a fiber of 60-80 nm in diameter that constitutes either one part of a turn or two or three turns of a helix within small and large double-spotted NORs, respectively. Within crescent-shaped NORs, virtual slices reveal that the fiber constitutes several longitudinally twisted loops, grouped as two helical 250- to 300-nm coils, each centered on a nonargyrophilic axis of condensed chromatin. We propose a model of the 3D organization of r-chromatin within elongated NORs, in which loops are twisted and bent to constitute one basic chromatid coil.
BACKGROUND: The cardiovascular effects of halothane are well recognized, but little is known of how this affects drug distribution. The effect of halothane anesthesia on physiologic factors that affect drug disposition from the moment of injection was investigated. METHODS: The dispositions of markers of intravascular space and blood flow (indocyanine green), extracellular space and free water diffusion (inulin), and total body water and tissue perfusion (antipyrine) were determined in four purpose-bred coonhounds. The dogs were studied while awake and while anesthetized with 1%, 1.5%, and 2% halothane in a randomized order determined by a repeated measures Latin square experimental design. Marker dispositions were described by recirculatory pharmacokinetic models based on frequent early and less frequent later arterial blood samples. These models characterize the role of cardiac output and its distribution on drug disposition. RESULTS: Halothane caused a significant and dose-dependent decrease in cardiac output. The disposition of antipyrine was most profoundly affected by halothane anesthesia, which increased both nondistributive intercompartmental clearance and volume while decreasing fast and slow tissue clearances and elimination clearance in a halothane dose-dependent manner. CONCLUSIONS: Halothane-induced changes in blood flow to the compartments of the antipyrine recirculatory model were not proportional to changes in cardiac output. Halothane anesthesia significantly increased (to more than double) the area under the drug concentration versus time curve due to an increase in the apparent peripheral blood flow not involved in drug distribution, despite a dose-dependent cardiac output decrease. Recirculatory pharmacokinetic models include the best aspects of traditional compartmental and physiologic pharmacokinetic models while offering advantages over both.
Periodontal-like tissues and, in particular, alveolar bone- and root cementum-like material can theoretically be modulated by release of biochemical agents such as bisphosphonate (PCP), growth hormone (GH) and alkaline phosphatase (ALP) from the implant surface. The present research focused on porous ceramic hydroxyapatite (PCHA) implants. In the past the PCHA implants were machined on a lathe out of simple blocks of PCHA ceramic. This was a tedious and cumbersome method, often resulting in implants with undesirable characteristics: different porosities, cracks and fractures. Therefore a moulding technique was developed to sinter near-net-shaped PCHA implants at 2 different sintering temperatures: 1170 degrees C and 1280 degrees C, resulting in PCHA implants with porosities of 62.06% (PCHA type 1) and 40.74% (PCHA type 2), respectively. After 1 h incubation in a 10(-2) M solution of PCP, the total amounts adsorbed onto PCHA type 1 and type 2 were 114.9 +/- 2.1 micrograms and 46.1 +/- 1.5 micrograms, respectively. This was approximately 5 times higher than after incubation for 1 wk in a 10(-4) M solution of PCP. The total amounts of PCP released after the observation period of 75 d from PCHA type 1 and type 2 after incubation in the 10(-2) M solution were 103.1 +/- 1.8 micrograms and 42.8 +/- 1.5 micrograms, respectively. The total amounts released from type 1 and 2 after incubation in the 10(-4) M solution were 7.4 +/- 0.4 micrograms and 4.1 +/- 0.1 micrograms, respectively. After 2 wk of incubation in a liver/bone/kidney ALP solution the total amount of ALP adsorbed onto PCHA type 1 implants was 5039 +/- 412 mU/ml. The total amounts of ALP released were 4674 +/- 438 mU/ml and 53 +/- 20 mU/ml after 1 and 2 wk, respectively. The release of ALP was high at the beginning but slowed down thereafter. It was evident that despite the well-known high bonding affinity of PCP to HA the release of PCP occurred steadily, over a long period of time in vitro.
We report a patient with a 30-year history of progressive, involuntary movements of the left ear and clicking sounds in both ears for 2 years. The patient had rhythmic contractions of the tensor veli palatini muscle and could relieve palatal movements and ear clicks, but not ear movements, by pressing a pillow against the left ear or by finger pressure on the tragus or the retroauricular region. We discuss the significance of these sensory tricks and the nosology of the long-standing ear movements within a classification of essential and symptomatic palatal tremor. Current diagnostic criteria for both types of palatal tremor may not cover some atypical cases such as ours.
We have previously demonstrated that nitric oxide (NO)-generating compounds inhibit D. discoideum differentiation by preventing the initiation of cAMP pulses (Tao, Y., Howlett, A. and Klein, C. (1996) Cell. Signal. 8, 37-43). In the present study, we demonstrate that cells produce NO at a relatively constant rate during the initial phase of their developmental cycle. The addition of oxyhemoglobin, an NO scavenger, stimulates cell aggregation, suggesting that NO has a negative effect on the development of aggregation competence. Starvation of cells in the presence of glucose, which has been shown to prevent the initiation of cAMP pulses (Darmon, M. and Klein, C. (1978) Dev. Biol. 63, 377-389), results in an increased production of NO. The inhibition of cell aggregation by glucose treatment can be reversed by oxyhemoglobin. These findings indicate that NO is a signaling molecule for D. discoideum cells and that physiological or environmental conditions that enhance external NO levels will delay the initiation of cAMP pulses, which are essential for cell differentiation.
Degradable hydroxyapatite (HA) implants complexed with the resorption inhibiting agent bisphosphonate (PCP) and the mineralizing agent alkaline phosphatase (ALP) can theoretically maintain alveolar bone mass directly after extraction of teeth. The present in vitro study investigated the surface properties of PCP-ALP-complexed HA implants in relation to the requirements of implant behavior and action. Adsorbed PCP (pH 3.49) resulted in a flattening and broadening of the phosphate peaks and the formation of carbonate peaks in the HA pattern of the implant indicating a chemical alteration of the HA surface. Adsorption of ALP onto PCP-altered HA surfaces was 26% lower than onto HA implant blank surfaces. PCP-ALP-complexed HA implants released the PCP and ALP steadily and continuously over observation periods of, respectively, 75 and 14 days. During these observation periods, the ceramic grains of the HA implant became smaller and intergrain boundaries became broader. These morphologic characteristics suggested preconditioning of the HA implant surface for future bonding and degradation in vivo. Individual grains were no longer bonded to other grains and detached from the implant which had become rounded in shape. From in vitro mice experiments we found that PCP concentrations between 10(-4) and 10(-3) M resulted in 45Ca-release from the bone HA. Our calculations showed, however, that only a total concentration of 1.4 x 10(-4) M PCP was gradually released over the whole observation period. In another experiment, it appeared that a PCP concentration in solution < 10(-3) M did not reduce ALP activity. It is concluded that release of PCP by the PCP-ALP-complexed implants is maintained at levels in the range to impair osteoclast bone resorption but not high enough to block osteoblast activity. The amount of ALP released can lead to induction of bone formation onto implant surfaces. pH-induced alterations in the microstructure and chemistry of the HA surface allow for controlled degradation of the HA implants in vitro. A PCP-ALP-complexed HA implant acting as temporary scaffolding for alveolar bone growth enhancement, mineralization, and maintenance seems to be a reasonable concept for preservation of the edentulous alveolus.
The tachyzoite of Toxoplasma gondii must successfully invade a host cell before it can replicate. Depletion of the Ca2+ in the external medium (EGTA) reduced tachyzoite invasion, suggesting that the initial tachyzoite-host cell interaction is Ca2+ dependent. The interaction of tachyzoites with host cells was also inhibited by Ca2+ channel blockers (verapamil) and calmodulin antagonists (trifluoperazine, calmidazolium). The calmodulin concentrated at the apical end of the tachyzoite could be involved in cytoskeleton movement and conoid extrusion. Invasion also depends on changes in tachyzoite cytosolic calcium. Depletion of Ca2+ with A23187+EGTA and release of Ca2+ from intratachyzoite pools (nuclear and perinuclear areas) inhibited invasion. In contrast, Ca-ionophore and thapsigargin which increase host cell cytosolic Ca2+, significantly decreased tachyzoite invasion. We therefore suggest that the effect of the drug is significantly different from the localized Ca2+ signal that is produced after parasite attachment to its host cell receptors and leads to its internalization into the host cell.
If treatment fails, mandibular hypoplasia, especially in unilateral cases, can cause severe facial asymmetries that worsen as the patient ages. Even distraction osteogenesis becomes more important as an early treatment concept, with regard to traditional therapies in a unidirectional application, if skeletal malformations are treated incompletely. In most cases of mandibular hypoplasia there are bone deficits in the vertical, horizontal and transverse direction, which lead to various problems in the skeletal profile. Therefore, we developed a multidirectional distractor to normalize a hypoplastic mandibular area in an almost anatomical manner. This device consists of two geared rods with a infinitely variable ball joint. It enables us to create one or two callus fields on each side and correct the profile on several levels. This is the decisive advantage in comparison with the intraoral devices that work only in one plane. Using a clinical example, the indication, technique and possibilities of multidirectional callus distraction are illustrated and discussed.
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