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At least 973 records · Page 54Linked to original sources
PubMed1976

[High frequency cinematographic investigations of the mode of operation of common drilling instruments on bone and cartilage (author's transl)].

High frequency cinematographic films were made of the mode of operation of common oto-surgical drilling instruments on bone and cartilage. Rose bits and surgical fraises of different sizes were used at 5,000-80,000 R.P.M. The evaluation of the slow motion pictures was performed on the running films and by review of single frames. In detail: The preparation of the drilling head on the bone without simultaneous flushing leads to a filling of the cutting channel and decreased cutting. Drop flushing only prevents the increasing soiling of the drilling head if the drop sequence is rapid and which must be markedly increased with increasing R.P.M. of the drilling instrument. Flushing with a stream of water, which definitely prevents soiling, is preferable. Both drop flushing as well as the water stream must continuously wet the drilling head, i.e. must be absolutely centric in every case. Safest is the automatic spray flusing which is mounted on the handpiece, but which has so far not been used in oto-surgery. During the preparation, the air space of the working area is always filled with drilling dust or haze. Cutting is always performed tangenitally. The cutting speed lies between 2,9 m/s to 16 m/s. It depends on the R.P.M. of the drilling instrument. A drill head running out of true, even with a gently percussing shaft, touches the bone only with a part of its cutting surface which strikes more vigorously than desired and easily gets soiled, despite flushing. Cutting is therefore less and uncontrolled. An increased feeding energy (pressure on the support) in order to speed up cutting leads to heavy wear of the drilling instrument and unsafety in handling due to jumping of the drilling head. During each contact of a cutter with the bone, coarse fraises with low R.P.M. (5,000 R.P.M. = 83 R/s) show a short stopping of the rotation which results in a jerk and vibration of the whole preparation and can thus lead to a damage of the inner ear.

Bone and Bones↗
PubMed1977

[High frequency cinematographic investigations of the mode of operation of common grinding instruments on bone and cartilage (author's transl)].

The mode of operation of grinding faces, rod diamonds and diamond grinding heads which are expecially employed in oto-surgery was investigated in slow motion pictures with the aid of high frequency cinematography. The R.P.M. ranged between 5,000-80,000, the picture frequency was usually 6,000 pictures per second. Full efficiency of the diamond grinding heads (DS) is only guaranteed by adequate flushing. Water stream flushing and drop flushing (drop sequence depending on R.P.M.) must be centered on the grinding head, as increased soiling due to filling of the diamond surface occurs otherwise. Because of the fixed mounting of the spray tube in the direction of the shaft, spray flushing is most useful, although not unsable for diamond faces. Due to its very fine-rough surface, the DS produces grinding dust by abrasion from the bone or cartilage which is readily distributed in the airspace over the whole working area. The same does also apply to finely atomized fluid sprays. Cutting is performed tangentially. The percussing DS touches the bone only with a small part of its surface and easily gets soiled. Depending on the R.P.M., the cutting speed was 10,000-80,000 R.P.M. These values also apply for the fluid dropping rate. Contrary to the rose bit or the surgical fraises, the DS got soiled more easily and produced definitely finer cuts.

Cartilage↗
PubMed1988

Axonal damage in severe traumatic brain injury: an experimental study in cat.

Based upon recent clinical findings, evidence exists that severe traumatic brain injury causes widespread axonal damage. In the clinical setting, it has been assumed that such axonal damage is the immediate consequence of traumatically induced tearing. However, in laboratory studies of minor head injury, evidence for primary traumatically induced axonal tearing has not been found. Rather the traumatic event has been linked to the onset of subtle axonal abnormalities, which become progressively severe over time (i.e., 12-24 h). In the light of these discrepant findings, we investigated, in the present study, whether progressive axonal change other than immediate tearing occurs with severe traumatic brain injury. Anesthetized cats were subjected to high intensity fluid-percussion brain injury. Prior to injury all animals received cortical implants of horseradish peroxidase (HRP) conjugated to what germ agglutinin to anterogradely label the major motor efferent pathways. Such an approach provided a sensitive probe for detecting traumatically induced axonal abnormality via both light microscopy (LM) and transmission electron microscopy (TEM). The animals were followed over a 1- to 6-h posttraumatic course, and processed for the LM and TEM visualization of HRP. Through such an approach no evidence of frank traumatically induced tearing was found. Rather, with LM, an initial intra-axonal peroxidase pooling was observed. With time, unilobular HRP-containing pools increased in size and progressed to bi- or multilobulated profiles. Ultimately, these lobulated configurations separated. Ultrastructurally, the initial unilobular pool was associated with organelle accumulation and focal axolemmal distention without frank disruption. Over time, such organelle accumulations increased in size and sequestered into multiple pools reminiscent of the bi- and multilobulated structures seen with LM. Ultimately, these organelle accumulations became detached, resulting in physically separated proximal and distal organelle-laden swellings surrounded by a distended axolemma and thinned myelin sheath. The findings reject the hypothesis that axons are immediately torn upon impact.

Animals↗
PubMedDate not supplied

Appendicitis diagnosis today: clinical and ultrasonic deductions.

A total of 111 patients referred with a diagnosis of suspected "appendicitis" were entered into a prospective study. The surgeon and radiologist in charge of ultrasonography made separate diagnoses, and their findings were then combined and discussed as indications for surgery. Clinically, a history of pain migration proved to be reliable (p < 0.0001) as a diagnostic indicator, in contrast to nausea and initial irregularity of bowels. The duration of symptoms was significantly shorter in patients with proved appendicitis than among patients with negative findings (median 24 hours compared with 41 hours, p < 0.04). Among patients with perforated appendicitis, the symptomatic history was prolonged (not significantly) by 3 hours. Peritoneal signs such as pain on percussion, rebound tenderness, guarding, and a leukocytosis of more than 13,000/mm3 were indicative of appendicitis (p = 0.0001 for each sign). Lively bowel sounds excluded the possibility of appendicitis (p = 0.001). Scanty bowel sounds, rectal tenderness, axillorectal temperature difference, and a left shift in leukocytes were of no diagnostic significance. The doctor's "clinical experience" is significant at the level of p < 0.03. On ultrasonography, the following signs were indicative of appendicitis: periappendicular infiltration (p = 0.0003), a visible "cockade," and an appendix larger than 12 mm in diameter (p = 0.04). For 75% of the patients the surgeon was sure of his own clinical diagnosis and did not allow himself to be influenced by the sonographic findings. In 12% of doubtful cases ultrasonographic results decisively favored operation, and in 4.5% (n = 5) it prevented an unnecessary laparotomy in the presence of positive clinical symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Hypermetabolic state following experimental head injury.

Local cerebral glucose utilization (LCGU) was studied in 35 conscious rats after a fluid percussion injury (cerebral contusion). The experiments were divided into two parts. (I) Natural course: LCGU was quantitatively measured in 17 rats by the 14C-deoxyglucose autoradiographic method (Sokoloff et al. 1977) at 1, 2, 4 and 24 hours after injury. Sham operation was made in six rats. (II) DC-potential and LCGU: LCGU was studied with DC-potential and EEG monitoring in 12 rats. Results were as follows: (I) i) Glucose uptake was reduced at the center of the contusion in all cases. ii) Two different effects were observed in LCGU change two hours after injury: normal or slight increase in four of six rats (type A) and a remarkable increase in the cortex of the injured hemisphere in two of six rats (type B). iii) The pattern of increase in LCGU (type B) resembles that of cortical spreading depression. (II) i) Negative shift of DC-potential concomitant with EEG suppression in the injured hemisphere was observed frequently one to two hours after injury. ii) The increased LCGU pattern during DC-potential negative shift was identical with that of type B. iii) LCGU pattern without DC-potential change resembles that of type A. We concluded that the hypermetabolism occurring in the damaged cortex was due to a spreading depression. The findings obtained here should yield very important information concerning pathogenesis and treatment of human head injury.

Animals↗
PubMed1996

Prevention of trauma-induced neurodegeneration in infant and adult rat brain: glutamate antagonists.

The mechanisms of neuronal degeneration following traumatic head injury are not well understood and no adequate treatment is currently available for the prevention of traumatic brain damage in humans. Seven day old rat pups were subjected to mechanical percussion of the head. Cortical damage in infant rats was reduced by pre-treatment with the N-methyl-D-aspartate (NMDA) antagonists dizocilpine (MK-801) or 3-((+/-)-2-carboxypiperazin-4-yl)-propyl-I-phosphonate (CPP). The AMPA antagonist 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo (f) quinoxaline (NBQX) did not significantly suppress cortical damage in infant rats. In adult rats, traumatic head injury leads to primary (at impact-cortex) and secondary (distant-hippocampus) damage to the brain. Morphometric analysis demonstrated that both cortical and hippocampal damage was mitigated by pre-treatment with either the NMDA antagonist CPP or the non-NMDA antagonist NBQX. Neither treatment prevented primary damage in the cortex when therapy was started after trauma. Delayed treatment of rats with NBQX, but not with CPP, beginning between 1 and 7 h after trauma prevented the hippocampal damage. No protection was seen when therapy with NBQX was started 10 h after trauma. These data indicate that NMDA antagonists may possess better neuroprotective properties against excitotoxic processes triggered by traumatic brain injury in young individuals whereas AMPA antagonists may be more beneficial in adults.

Animals↗
PubMed1992

Neurological examination in patients recovering from general anesthesia.

We performed serial neurological evaluations on 86 patients who underwent surgery for herniated lumbar disk during the first 3 hours after the end of anesthesia (isoflurane-N20-02 for 25 patients, halothane-N20-02 for 38, fentanyl-droperidol-N20-02 for 23). At time 0, the idiomuscular response to percussion of the extensor carpi muscle was present in every patient, while tendon reflexes were always absent. Hyperreflexia was as frequent as shivering, but it took place earlier; we could determine no correlation between these two phenomena. There was no correlation between shivering and rectal temperature of the patients. Although almost all the patients were cooperative and could correctly calculate 100-7, the post-hyperventilation-apnea test was positive in 35 patients at time 120 minutes: this suggests that many patients considered "awake" still exhibit neurological abnormalities, such as inadequate respiratory drive.

Adolescent↗
PubMed2002

Pathophysiological changes after traumatic brain injury: comparison of two experimental animal models by means of MRI.

In an experimental study MRI was used to compare the pathophysiological changes of brain tissue after lateral fluid percussion injury (FPI) versus cold injury (CI) as models of traumatic brain injury (TBI). Two groups of Sprague-Dawley rats (n=23) were subjected to mild FPI, respectively, CI localized over the right parietal cortex. MRI was performed at different time points including T1w, T2w and T1w-CE (Gd-DTPA 0.2 mmol/kg BW) sequences as well as perfusion-weighted imaging with calculation of regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF). T2w and T1w-CE images showed hyperintense areas in the traumatised cortex demonstrating brain edema and blood-brain barrier (BBB)-breakdown increasing up to 12 h. Perfusion-weighted imaging demonstrated a significant decrease of rCBV and rCBF in the ipsilateral cortex of CI animals compared with the contralateral hemisphere. In contrast, rats of the FPI group showed only slight differences in rCBF and rCBV comparing the left and right cortex. The results of our study confirm that both mild FPI and CI produced focal brain edema with concomitant breakdown of the BBB as a model of TBI. Since differences regarding perfusion are much more pronounced in CI our results suggest that, this model more likely seems to reflect pathophysiological changes of brain ischemia, whereas FPI seems to be better suited to model the pathophysiological characteristics of TBI.

Animals↗
PubMed1990

The role of chest physiotherapy in mucus hypersecretion.

Review of the data shows that chest physiotherapy (CP) is effective in clearing secretions from the lungs of patients with copious secretions (i.e., daily sputum production in excess of 30 ml). Assessment of the various components of CP shows that percussion, vibratory shaking, and breathing exercises have little to offer. Although instructed cough, the back up mucus clearance mechanism, is effective in clearing secretions its effect is less than that achieved with the forced expiration technique (FET). Postural drainage (PD) is on the whole successful in helping to drain secretions in the lungs. The administration of a beta 2-agonist via a nebulizer prior to CP in addition to promoting bronchodilation may also help to alter the physical properties of secretions, rendering them more amenable for clearance by FET/cough. Technology regarding high-frequency oscillations (HFO) has yet to be improved and its efficacy in clearing excess secretions proven prior to its inclusion in a CP treatment regimen. Intermittent positive pressure breathing (IPPB) may have a role to play in those patients where conventional CP is not possible. Data with positive expiratory pressure (PEP) are encouraging and direct evaluation is awaited regarding its effect on mucus clearance. With our present knowledge it seems reasonable to recommend that physiotherapists concentrate their CP treatment on the following: administration of a nebulized beta 2-agonist followed by PD and FET.

Breathing Exercises↗
PubMed2001

Congenital myotonic dystrophy.

Myotonic muscular dystrophy is the most frequent autosomal muscular dystrophy affecting adults and children. It affects multiple organ systems and is probably the best example of variable expressivity in a human disease. This article presents a patient with congenital myotonic dystrophy who had facial dysmorphism, hypotonia, talipes, feeding and respiratory difficulties in the neonatal period and later presented to us with developmental delay and had percussion myotonia. His mother had clinical and electrophysiological features of myotonia. Expansion of unstable CTG trinucleotide repeat in the myotonic protein kinase gene was demonstrated in both. The identification of this molecular defect allows its specific diagnosis in relation to other neuromuscular disorders as well as accurate prenatal diagnosis.

Child, Preschool↗
PubMedDate not supplied

Inhibition of nitric oxide synthase potentiates hypertension and increases mortality in traumatically brain-injured rats.

We examined the effects of N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), on mortality, morbidity, and cardiovascular parameters following traumatic brain injury (TBI) in the rat. Rats were anesthetized with 2% isoflurane prior to moderate (2.0 atmosphere), central fluid percussion TBI. Temporalis muscle temperature was maintained at 37 +/- 0.5 degrees C. L-NAME (10 mg/kg iv) was administered once at either 5 min before, 5 min after, or 15 min after TBI. Sensorimotor deficits and spatial learning/ memory deficits were assessed after injury. Separate groups of rats were monitored for cardiovascular parameters. Preinjury administration of L-NAME significantly increased mortality from 13 (vehicle) to 70% (associated with pulmonary edema), whereas postinjury, L-NAME had no effect on mortality (14 and 25%). L-NAME administered at 5 or 15 min after injury had no significant effect on motor performance or cognitive performance deficits associated with TBI. L-NAME in uninjured rats increased arterial blood pressure by 25 mmHg within 2 min. L-NAME injected 5 min before TBI greatly prolonged the hypertensive episode associated with TBI (1 min in vehicle vs 60 min in L-NAME). L-NAME injected 5 min after TBI caused a sustained 35 mmHg increase in blood pressure. These findings suggest that acute inhibition of NOS has detrimental consequences on mortality that may be owing to its cardiovascular effects.

Analysis of Variance↗
PubMed2004

Safety of blind liver biopsy.

OBJECTIVE: The aim of the study was to observe the safety of blind liver biopsy in children. METHODS: One hundred fifteen consecutive liver biopsies in hospitalized children were evaluated retrospectively. Using a standard percussion technique biopsy sites were chosen and through intercostal space blind liver biopsies were performed by TruCut biopsy needle. RESULTS: The first biopsy sample was considered macroscopically adequate in 94.8% of cases. A definitive histological diagnosis was possible in 99.1% of cases. Sixty nine children were more than 5 years of age and of these 8 (11.6%) complained of pain at the biopsy site. External hemorrhage from the biopsy site was seen in 1 (0.9%) case but no sign of internal hemorrhage was detected during the 24 hours follow up period. No child died following the procedure. CONCLUSION: Blind liver biopsy in the studied hospitalized children was found to be a safe procedure.

Adolescent↗
PubMed2001

Multiple thymoma with myotonic dystrophy.

A case of multiple thymoma associated with myotonic dystrophy is reported. The patient was a 42-year-old man who had two separate encapsulated thymoma in the anterior mediastinum, at 3 cm in diameter on the right side, and at 4 cm in diameter on the left. Extended thymo-thymomectomy was performed. Microscopically, the tumor in the right thymic lobe was predominantly mixed type, and that in the left predominantly epithelial type. Neuromuscular disease appeared to develop, with severe sputum retention in the larynx and he was referred to neurology at 6 months after surgery. On examination, he presented a characteristic hatchet face, muscle atrophy, muscle weakness, percussion myotonia and grip myotonia, and diagnosis was revised to be multiple thymoma associated with myotonic dystrophy. This association is extremely rare. It is difficult to clarify whether this association was a syndrome or coincidence.

Adult↗
PubMed2004

Common patterns of bcl-2 family gene expression in two traumatic brain injury models.

Cell death/survival following traumatic brain injury (TBI) may be a result of alterations in the intracellular ratio of death and survival factors. Bcl-2 family genes mediate both cell survival and the initiation of cell death. Using lysate RNase protection assays, mRNA expression of the anti-cell death genes Bcl-2 and Bcl-xL, and the pro-cell death gene Bax, was evaluated following experimental brain injuries in adult male Sprague-Dawley rats. Both the lateral fluid-percussion (LFP) and the lateral controlled cortical impact (LCI) models of TBI showed similar patterns of gene expression. Anti-cell death bcl-2 and bcl-xL mRNAs were attenuated early and tended to remain depressed for at least 3 days after injury in the cortex and hippocampus ipsilateral to injury. Pro-cell death bax mRNA was elevated in these areas, usually following the decrease in anti-cell death genes. These common patterns of gene expression suggest an important role for Bcl-2 genes in cell death and survival in the injured brain. Understanding the regulation of these genes may facilitate the development of new therapeutic strategies for a condition that currently has no proven pharmacologic treatments.

Animals↗
PubMedDate not supplied

Effects of traumatic brain injury in rats on binding to forebrain opiate receptor subtypes.

Sprague-Dawley rats were subjected to a moderate level (2.2 atm) of traumatic brain injury (TBI) using fluid percussion. Injured animals were allowed to survive posttrauma for periods of 5 min, 3 h, and 24 h. The effect of TBI on binding to forebrain opiate receptors was assessed using quantitative receptor autoradiography, and compared to a sham control group. Binding of [3H]DAGO to mu receptors in neocortex and the CA1 pyramidal layer of the hippocampus was significantly decreased in the 24-h group (p less than 0.05). [3H]Bremazocine binding to kappa receptors was unchanged at 5 min and 24 h, but showed large decreases 3 h after TBI in the CA1 pyramidal layer (65%, p less than 0.05) and dentate gyrus (43%, p less than 0.05). Levels of delta binding (measured with [3H]DSLET) and lambda binding (measured with [3H]naloxone) were unaffected by TBI. These data support previous suggestions of a role for endogenous opioids in TBI, and provide further evidence that mu and kappa opioid receptor subtypes in neocortex and hippocampus may have different functions in TBI.

Amino Acid Sequence↗
PubMed1993

Hypothermia blunts acetylcholine increase in CSF of traumatically brain injured rats.

Activation of muscarinic acetylcholine (ACh) receptors contributes to the pathophysiological consequences of moderate experimental traumatic brain injury (TBI). Hypothermia (30 degrees C) provides protection in experimental TBI. We measured ACh levels in CSF and plasma 5 min after moderate fluid percussion TBI under normothermic or hypothermic conditions, because ACh in the CSF has been correlated with the severity of behavioral deficits after TBI. Three groups were examined: TBI with hypothermic brain (30 degrees C), TBI with normothermic brain (37 degrees C), or sham TBI with normothermic brain (37 degrees C). ACh concentrations in CSF were significantly higher in 37 degrees C TBI rats, but not in 30 degrees C TBI rats compared to shams. ACh concentrations in plasma did not differ between groups. These results suggest that a contributing factor to the neuroprotective effects of moderate hypothermia in TBI may be related to the reduction of excessive ACh levels in the central nervous system following injury.

Acetylcholine↗
PubMed2004

[Acute exacerbation of COPD].

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) often develop into emergency situations that are associated with high morbidity and mortality. There is still a lack of a generally accepted definition for the risk stratification in AECOPD to guide an optimal diagnosis and treatment. In this article we propose a classification based on 4 degrees of severity, depending on whether outpatient treatment can be done by the patient himself or is provided by a physician and whether inpatient treatment is carried out on a general ward or on an intensive care unit. The pharmacological therapy of AECOPD relies on short acting bronchodilators, systemic corticosteroids and in case of purulent sputum on antibiotics. Longacting beta(2)-agonists or anticholinergics, theophyllin, mucolytic drugs or mechanical percussion to the chest by a physiotherapist have no proven value in the emergency treatment of AECOPD. In respiratory failure the use of oxygen therapy and non-invasive positive pressure ventilation (NIPPV) can often prevent the need for endotracheal intubation and controlled mechanical ventilation, thus preventing associated risks like the development of nosocomial pneumonia.

Acute Disease↗
PubMed2006

Renal colic during sexual intercourse: a unique presentation.

The average lifetime risk of renal stones has been reported to be in the range of 5-21%, and the majority of patients have recurrent stones (Tiselius et al. in Eur Urol 40:362-371, 2001). The peak incidence is between the fourth and fifth decades, and therefore generally active and working adults are most affected. Stones are usually formed in a calyx, and become symptomatic if they move to obstruct the upper urinary tract. In the majority of cases, there is no specific action which causes stone movement from a non-obstructing to an obstructing position. We present the first ever case report in the literature of an episode of renal colic during sexual intercourse. The role of percussion therapy and postural drainage are well established following shockwave lithotripsy (SWL) to enhance passage of lower pole stone fragments (Brownlee et al. in J Urol 143:1096, 1990), and it may well be the result of similar principles of motion and body positioning which caused the patient to present in this manner.

Adult↗