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Contemporary management of deep neck space infections.

Deep neck infections continue to be seen despite the wide use of antibiotics. These infections follow along fascial planes to create deep neck space abscesses. The clinical presentation often points to the space involved. Understanding the regional anatomy gives the surgeon the ability to treat these grave infections. The records of 24 patients with a diagnosis of deep neck space abscess admitted to Hermann Hospital between 1988 and 1993 were reviewed. Fifty percent of the patients had received antibiotics for an infection of the ear, nose, or throat before the development of a neck space abscess. Ten patients had parapharyngeal abscesses, seven had retropharyngeal abscesses, six had submandibular space abscesses, and one had parotid space abscess. Thirty-five organisms were isolated in 18 cases (1.9 isolates per patient). The most common organism cultured was Streptococcus (13 of 18), followed by Staphylococcus (6 of 18), Bacteroides (5 of 18), Micrococcus (2 of 18), and Neisseria (2 of 18). One case each of Candida, Enterobacter, Enterococcus, Peptostreptococcus, Proteus, Proprionobacter, and Pseudomonas was cultured. Six patients had no growth on culture but did have organisms found on Gram's stain. The operative techniques and antibiotics used are discussed. The main complications of jugular vein thrombosis, carotid artery rupture, and mediastinitis are described, as well as an unusual case of meningitis from a large retropharyngeal-parapharyngeal abscess.

Adolescent↗

Negotiating spaces in home environments: older women living with arthritis.

Within medical geography there has been a surge of interest in applying critical concepts in social theory to empirical settings, including those for persons with disabilities. The ways through which persons with disabilities negotiate space vary widely according to material and social experiences of being disabled. For older women, chronic illness as a type of disability shapes the way in which they approach their daily lives with respect to both the physical and social aspects of their home environments. In the first half of the paper, conceptually, I take a relational view of space and argue that household, as a narrow reading of domestic space, needs to be replaced by home environment which incorporates more fully age- and ablement-sensitive readings of the spaces constitutive of domestic space. This lays the basis for a contextualized socio-spatial understanding of the ways older women with chronic illness negotiate the spaces in home environments because it accounts for the disadvantaged positionings of access to power and resources as well as the uneven distributions of income based on gender, age, and (dis)ability. It also takes into account the material and social aspects of being disabled. In the second half of the paper, I present case studies of three older women diagnosed with rheumatoid arthritis to illustrate these arguments.

Activities of Daily Living↗

Assessment of the pharyngeal airway space after mandibular setback surgery.

PURPOSE: This retrospective study evaluated the change in pharyngeal airway space associated with surgical mandibular setback. PATIENTS AND METHODS: Lateral cephalograms of 14 adult patients taken preoperatively, immediately postoperatively, and at long-term follow-up were traced, and the width of the pharyngeal airway space and the pharyngeal airway space area were calculated and compared. RESULTS: At long-term follow-up, the mean amount of mandibular setback was 9.7 mm. The mean reduction in the distance from the tongue base to the posterior pharyngeal wall was 4.77 mm (28% decrease). The mean reduction in pharyngeal airway space area was 1.52 cm2, which corresponded to a 12.8% reduction. There was a strong correlation between the amount of mandibular setback and the decrease in pharyngeal airway space area. CONCLUSION: Mandibular setback surgery causes a long-term decrease in pharyngeal airway space area. In patients who have other risk factors, for example, overweight, short necks, or large tongues, a mandibular setback procedure could possibly predispose to the development of sleep apnea syndrome.

Adolescent↗

Optimum scan spacing for three-dimensional ultrasound by speckle statistics.

A technique is introduced to determine the spacing between acquired two-dimensional (2-D) planes necessary to maintain resolution in the scan direction while maximizing scan speed for 3-D ultrasound (US) imaging. We performed statistical analysis on a series of 3-D scans of agar blocks with different image spacings, quantifying speckle size (S(c)) as the full-width half-maximum (FWHM) of the autocovariance function. S(c) was approximately constant at small 2-D image-plane spacings, but increased after the scan spacing surpassed some optimum point. Optimum spacing ranged between 0.075 and 0.4 mm, increasing with the axial depth and the number of focal zones. This latter dependence is a result of successive sampling by the US machine and the digitizer at unequal rates, as demonstrated through an analysis of the noise power spectra. This analysis predicted that S(c) may be significantly reduced by using a transducer sampling rate that is twice the digitization rate. This technique permits the calculation of the most efficient scan spacings for 3-D US imaging.

Artifacts↗

Use of reciprocal lattice layer spacing in electron backscatter diffraction pattern analysis

In the scanning electron microscope using electron backscattered diffraction, it is possible to measure the spacing of the layers in the reciprocal lattice. These values are of great use in confirming the identification of phases. The technique derives the layer spacing from the higher-order Laue zone rings which appear in patterns from many materials. The method adapts results from convergent-beam electron diffraction in the transmission electron microscope. For many materials the measured layer spacing compares well with the calculated layer spacing. A noted exception is for higher atomic number materials. In these cases an extrapolation procedure is described that requires layer spacing measurements at a range of accelerating voltages. This procedure is shown to improve the accuracy of the technique significantly. The application of layer spacing measurements in EBSD is shown to be of use for the analysis of two polytypes of SiC.

Journal Article↗

Prognostic influence of parapharyngeal space involvement in nasopharyngeal carcinoma.

PURPOSE: To assess the prognostic influence of parapharyngeal space involvement in nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: From January 1987 to December 1994, 197 untreated NPC patients were examined by CT scan before treatment. The parapharyngeal space was separated into pre-styloid and post-styloid compartments on axial images by the styloid process. Potentially significant parameters were analyzed by both univariate and multivariate methods using SPSS 8.0 software. RESULTS: The actual survival, disease-free survival, and local failure-free rates were affected by the presence of parapharyngeal space involvement (p = 0.0115, p = 0.0035, p = 0.0367, respectively). The 5-year actual survival, disease-free survival, and the local failure-free rates in the patients without parapharyngeal space disease, or with pre-styloid and post-styloid compartment involvement were 87.9%, 88.0%, 96.9% and 75.0%, 71.2%, 93.7% and 60.5%, 57.7%, 86.8%, respectively. Parapharyngeal space involvement correlated well with lymphadenopathy and advanced N disease. Distant metastasis is more likely in the presence of obvious post-styloid compartment involvement (p = 0.0153). Age is a strong prognostic factor for survival. CONCLUSION: Parapharyngeal tumor involvement has significant predictive value. The parapharyngeal space involvement affects local tumor failure, regional tumor failure, and distant metastasis. Its survival rate is low

Adolescent↗

Guyon's canal revisited: an anatomic study of the carpal ulnar neurovascular space.

The boundaries of the space through which the ulnar neurovascular bundle crosses the wrist have been reinvestigated. Using gross dissections, transverse and sagittal sections, and histologic study, we determined that the roof of Guyon's canal, the "carpal ulnar neurovascular space," does not directly connect to the hamate bone, as is currently accepted. The roof of this space extends radially to the hook of hamate and attaches to the flexor retinaculum. This anatomic arrangement allows the ulnar artery and sensory component of the ulnar nerve to course radially to the hook of hamate, where they lie on the flexor retinaculum (transverse carpal ligament). The roof and radial border have three segments: (1) a proximal segment that begins near the pisiform and extends distally to the level of the hook of hamate but does not attach directly to it, (2) a central segment that contains only adipose tissue, and (3) a distal fascial layer that includes the palmaris brevis muscle. The floor of the space consists of the muscles of the hypothenar eminence, their fibers of origin, and the flexor retinaculum (transverse carpal ligament). Guyon accurately described the proximal portion of the carpal ulnar neurovascular space, but his description has been misinterpreted; the hook of hamate does not serve as the radial boundary of Guyon's canal. The anatomic relationships of the "carpal ulnar neurovascular space" need to be appreciated to avoid complications during carpal tunnel surgery.

Cadaver↗

Increased power generation in a continuous flow MFC with advective flow through the porous anode and reduced electrode spacing.

The maximum power generated in a single-chamber air-cathode microbial fuel cell (MFC) has previously been shown to increase when the spacing between the electrodes is decreased from 4 to 2 cm. However, the maximum power from a MFC with glucose (500 mg/L) decreased from 811 mW/ m2 (R(ex) = 200 omega, Coulombic efficiency of CE = 28%) to 423 mW/m2 (R(ex) = 500 omega, CE = 18%) when the electrode spacing was decreased from 2 to 1 cm (batch mode operation, power normalized by cathode projected area). This decrease in power was unexpected as the internal resistance decreased from 35 omega (2-cm spacing) to 16 omega (1-cm spacing). However, providing advective flow through the porous anode toward the cathode substantially increased power, resulting in the highest maximum power densities yet achieved in an air-cathode system using glucose or domestic wastewater as substrates. For glucose, with a 1-cm electrode spacing and flow through the anode with continuous flow operation of the MFC, the maximum power increased to 1540 mW/m2 (51 W/m3) and the CE increased to 60%. Using domestic wastewater (255 +/- 10 mg of COD/L), the maximum power density was 464 mW/m2 (15.5 W/m3; CE = 27%). Although flow through the anode could lead to plugging, especially for particulate substrates such as domestic wastewater, the system was operated using glucose for over 42 days without clogging. These results show that power output in this air-cathode single-chamber MFC can be increased by reducing the electrode spacing if the reactors are operated in continuous flow mode with advective flow through the anode toward the cathode.

Electrochemistry↗

Revising current two-process accounts of spacing effects in memory.

Memory for repeated items improves when presentations are spaced during study. In Experiment 1A, words were repeated either immediately or after 6 intervening items. Intentional learning occurred under either focused or divided attention. Retention was tested by either free recall or yes-no recognition. Divided attention did not affect the influence of spacing in free recall, whereas it removed the spacing effect in recognition. In Experiment 1B, recognition memory was tested after incidental semantic study of words performed under either focused or divided attention. An equivalent spacing effect occurred in both attentional conditions. In Experiments 2 and 3, recognition memory for unfamiliar faces was assessed. A reliable spacing effect was found under both intentional learning and incidental structural study. These data are, collectively, incompatible with current theories of spacing effects. A theoretical proposal to account for these new findings is outlined.

Attention↗

Direct chemical measurement of the lambda of the lumped constant of the [14C]deoxyglucose method in rat brain: effects of arterial plasma glucose level on the distribution spaces of [14C]deoxyglucose and glucose and on lambda.

The lumped constant in the operational equation of the 2-[14C]deoxyglucose (DG) method contains the factor lambda that represents the ratio of the steady-state tissue distribution spaces for [14C]DG and glucose. The lumped constant has been shown to vary with arterial plasma glucose concentration. Predictions based mainly on theoretical grounds have suggested that disproportionate changes in the distribution spaces for [14C]DG and glucose and in the value of lambda are responsible for these variations in the lumped constant. The influence of arterial plasma glucose concentration on the distribution spaces for DG and glucose and on lambda were, therefore, determined in the present studies by direct chemical measurements. The brain was maintained in steady states of delivery and metabolism of DG and glucose by programmed intravenous infusions of both hexoses designed to produce and maintain constant arterial concentrations. Hexose concentrations were assayed in acid extracts of arterial plasma and freeze-blown brain. Graded hyperglycemia up to 28 mM produced progressive decreases in the distribution spaces of both hexoses from their normoglycemic values (e.g., approximately -20% for glucose and -50% for DG at 28 mM). In contrast, graded hypoglycemia progressively reduced the distribution space for glucose and increased the space for [14C]DG. The values for lambda were comparatively stable in normoglycemic and hyperglycemic conditions but rose sharply (e.g., as much as 9-10-fold at 2 mM) in severe hypoglycemia.

Adrenal Glands↗

Water- and solute-accessible spaces of purified peroxisomes. Evidence that peroxisomes are permeable to NAD+.

Peroxisomes were purified from liver homogenates from rats, treated with the peroxisome proliferator clofibrate, by a combination of differential centrifugation and isopycnic centrifugation in iso-osmotic self-generating Percoll gradients. Structural integrity of the peroxisomes appeared to be preserved as evidenced by a high degree of catalase latency, the absence of catalase release during purification and the exclusion of inulin (mol.wt. +/- 5000). Spaces for water and solutes were measured after incubation of the peroxisomes in iso-osmotic sucrose with radioactive water or solutes and separation of the organelles from their media by centrifugation through an organic layer. Extraperoxisomal water was corrected for by the use of radioactive dextran or inulin. The sucrose, glucose, urea, methanol and acetate-accessible spaces were identical, suggesting that these spaces represent the volume in which molecules that can cross the membrane distribute. This volume equalled 50-65% of the water space. Urate and NAD+, a cofactor of peroxisomal beta-oxidation of fatty acids, also distributed in this volume, but were also partly bound. Urate and NAD+ binding was not abolished by sonication, which released the bulk of matrix catalase activity, but NAD+ binding was seriously diminished. The peroxisomal water and sucrose spaces were estimated to be 107 microliters and 55 microliters per g of liver tissue from a clofibrate-treated rat. From quantitative morphometric data [Anthony, Schmucker, Mooney & Jones (1978) J. Lipid Res. 19, 154-165] and our marker enzyme analyses, as well as from our experimentally determined water spaces of mitochondrial and microsomal fractions, it could be calculated that the volume contamination by lysosomes, mitochondria and microsomes did not exceed 1, 8 and 6% respectively. Our data indicate that apparently intact peroxisomes are permeable to a number of small molecules, including NAD+. Whether the NAD+-binding sites in sonicated peroxisomes mirror the likely existence of a membrane carrier requires further investigation.

Animals↗

Characteristics of the lax vowel space in dysarthria.

It has been hypothesized that lax vowels may be relatively unaffected by dysarthria, owing to the reduced vocal tract shapes required for these phonetic events (G. S. Turner, K. Tjaden, & G. Weismer, 1995). It also has been suggested that lax vowels may be especially susceptible to speech mode effects (M. A. Picheny, N. I. Durlach, & L. D. Braida, 1986). Studies evaluating these suggestions are lacking, however. The present study was an initial investigation of the vowel space area formed by the lax vowels /Iota/, /epsilon/, and /upsilon/, occurring in a passage read in habitual, fast, and slow conditions by speakers with amyotrophic lateral sclerosis (ALS), speakers with Parkinson's disease (PD), and healthy controls. Vowel space areas for speakers with ALS but not speakers with PD differed from those for the appropriate control group. Thus, only the results for the PD group support the hypothesis that lax vowel space areas for speakers with dysarthria should be similar to those for neurologically normal talkers. Compared with the habitual condition, rate reduction was associated with an expanded vowel space area for all of the healthy talkers but for only about half of the speakers with dysarthria. In addition, about half of the speakers in each group demonstrated a reduced vowel space area for the fast condition relative to the habitual condition, although the statistical analyses indicated no difference in vowel space areas for the fast and habitual conditions. The current study therefore provides only limited support for the idea that lax vowels are highly susceptible to speech mode effects, at least when the speech modes under consideration include faster-than-normal and slower-than normal rates. Clinical implications are discussed.

Adult↗

The subpyloric space: an important surgical and radiologic feature in pseudomyxoma peritonei.

AIMS: If mucinous appendiceal tumours widely distributed throughout the peritoneal space are completely removed by peritonectomy procedures, quality of life and survival benefits result with an acceptable morbidity and mortality. In some patients mucinous tumour that surrounds the stomach is an important consideration in accomplishing a complete cytoreduction. METHODS: Mucinous tumour that enters the lesser sac through the foramen of Winslow will accumulate by gravity in the subpyloric space. This is a cul-de-sac beneath the pylorus. For complete cytoreduction mucinous tumour accumulation in the subpyloric space must be cleared. RESULTS: If there is tumour accumulation in the subpyloric space and the left gastric artery can be preserved by peritonectomy, one can achieve a complete cytoreduction without gastrectomy. In a majority of patients, resection of mucinous tumour from the subpyloric space requires total gastrectomy for complete cytoreduction. CONCLUSION: Knowledge of mucinous tumour distribution and anatomy of the subpyloric space will facilitate complete cytoreduction in selected patients with pseudomyxoma peritonei syndrome.

Antineoplastic Combined Chemotherapy Protocols↗

The effect of continuous cryotherapy on glenohumeral joint and subacromial space temperatures in the postoperative shoulder.

PURPOSE: The objective of this investigation was to determine the effect of continuous cryotherapy on glenohumeral joint and subacromial space temperatures in the postoperative shoulder. TYPE OF STUDY: Prospective, randomized, and controlled clinical trial. METHODS: Twenty patients (10 cryotherapy, 10 controls) with a full-thickness rotator cuff repair were monitored with temperature sensors in the glenohumeral joint and subacromial space of the shoulder for 23 postoperative hours. Statistical analysis (P <.05) was performed using the Mann-Whitney rank-sum test. RESULTS: In comparing the cryotherapy and control groups, analysis of the glenohumeral joint and subacromial space temperatures revealed a statistical significance at 4, 8, and 23, and 4, 8, 16, and 20 postoperative hours, respectively. In addition, a trend toward a temperature-rising phase occurs from 4 to 12 hours and is followed by a trend toward a thermostatic phase from 12 to 23 hours during which temperatures remain relatively constant. The subacromial space was consistently cooler than the glenohumeral joint by an interval between 0.07 degrees C to 0.50 degrees C except at 23 hours postoperative where the glenohumeral joint was 0.05 degrees C cooler. CONCLUSIONS: Continuous cryotherapy causes a statistically significant reduction of both glenohumeral joint and subacromial space temperatures in the shoulder at variable times during the first 23 postoperative hours. Previous investigations have shown that minor elevations in intra-articular temperature can stimulate proteolytic enzyme activity, which has detrimental effects on articular cartilage. Previous research has also shown that cryotherapy is an effective nonpharmacological method of pain control. Yet the literature has assumed that the effects of cryotherapy are part of the basic analgesia mechanism because of a reduction in joint temperature. Our results affirm that reductions in glenohumeral joint and subacromial space temperatures in the postoperative shoulder do occur, leading to potential benefits of continuous cryotherapy as an effective mode of pain control in the postoperative care of patients.

Aged↗

Meniscal subluxation: association with osteoarthritis and joint space narrowing.

OBJECTIVE: Since complete meniscectomy leads to knee OA, we investigated the potential links among meniscal subluxation, joint space narrowing and symptomatic OA. MATERIALS AND METHODS: 233 cases with symptomatic knee OA and 58 asymptomatic controls underwent radiography and MR imaging of the knee. Joint space narrowing was measured on weight-bearing PA fluoroscopy-positioned radiographs. The amount of medial or lateral meniscal subluxation was measured on coronal MR images. The prevalence and severity of meniscal subluxation was compared in cases and controls. We evaluated the correlation of the degree of meniscal subluxation with joint space narrowing, Kellgren and Lawrence grade, and two major risk factors for the development of OA, age and weight. RESULTS: Cases had more medial and lateral subluxation than controls. Mean medial meniscal subluxation was 5.1 mm in cases and 2.8 mm in controls (P=0.001). Modest degrees of meniscal subluxation were common in both cases and controls: 81% of cases and 64% of controls had >/=3 mm of subluxation; age and gender adjusted (P=0.006). Severe degrees of subluxation were almost unique to OA cases (e.g. prevalence of >/=7 mm, 35% cases vs. 7% controls, P< 0.001). Among controls, severe degrees of subluxation were present only in those with radiographic joint space narrowing (defined as >/=grade 1 narrowing on a 0-3 scale). In cases, there was a strong correlation between the degree of medial meniscal subluxation and the severity of medial joint space narrowing (r=0.56, P=0.0001). Similar results were present in the lateral compartment. Meniscal subluxation did not correlate with age or weight. CONCLUSION: Meniscal subluxation is highly associated with symptomatic knee OA. In subjects with osteoarthritis, increasing meniscal subluxation on MR correlates with the severity of joint space narrowing.

Adult↗

Space-time clustering patterns in childhood leukaemia support a role for infection.

Previous studies of space-time clustering in childhood leukaemia have produced equivocal and inconsistent results. To address this issue we have used Manchester Children's Tumour Registry leukaemia data in space-time clustering analyses. Knox tests for space-time interactions between cases were applied with fixed thresholds of close in space, <5 km and close in time <1 year apart. Addresses at birth as well as diagnosis were utilized. Tests were repeated replacing geographical distance with distance to the Nth nearest neighbour. N was chosen such that the mean distance was 5 km. Data were also examined by a second order procedure based on K-functions. All methods showed highly significant evidence of space-time clustering based on place of birth and time of diagnosis, particularly for all leukaemias aged 0-14 and 0-4 years, and acute lymphoblastic leukaemia (ALL) 0-4 years. Some results based on location at diagnosis were significant but mainly gave larger P-values. The results are consistent with an infectious hypothesis. Furthermore, we found an excess of male cases over females involved in space-time pairs. We suggest this may be related to genetic differences in susceptibility to infection between males and females. These findings provide the basis for future studies to identify possible infectious agents.

Adolescent↗

[Space-occupying lesion of the pancreas--how frequently not due to a suspected ductal adenocarcinoma?].

In patients with a space-occupying lesion of the pancreas at first a primary ductal adenocarcinoma is considered as the cause. Other tumours or metastases are assumed to occur very rarely. Therapy and prognosis of other pancreas tumours differ from therapy and prognosis of a primary ductal adenocarcinoma. We therefore examined the question of how frequently a space-occupying lesion of the pancreas was not due to a ductal adenocarcinoma in our case materials. Retrospectively 70 patients who had undergone a percutaneous puncture of a space-occupying mass of the pancreas under ultrasonographic control were included in the study (34 women, 36 men). In 62 patients a clear histological diagnosis was possible on the basis of the biopsy. In 53 cases (76 %) a primary adenocarcinoma of the pancreas could be diagnosed. In 5 patients (7 %) these masses turned out to be metastases of a previously known malignant tumour disease (2 x mammary carcinoma, 2 x gastric carcinoma, 1 x sigmoid carcinoma). Other tumours could be detected in 4 cases (6 %) including a tuberculoma, an endocrine tumour, a fusocellular sarcoma with partial neurogenic differentiation and a large-cell and pleomorphic-cell anaplastic, partly sarcomatoid carcinoma. In patients with a space-occupying lesion of the pancreas, tumours other than a ductal adenocarcinoma are not rare. In particular, in cases of a previously known malignant tumour disease a space-occupying lesion of the pancreas can also turn out to be a metastasis. Every other individual tumour entity is rare. Other tumour entities at large, however, are found in daily routine. The preoperative biopsy of space-occupying lesions of the pancreas, therefore, still has a clinical importance for the further therapy planning.

Aged↗

Symmetry of quantum phase space in a degenerate Hamiltonian system.

The structure of the global "quantum phase space" is analyzed for the harmonic oscillator perturbed by a monochromatic wave in the limit when the perturbation amplitude is small. Usually, the phenomenon of quantum resonance was studied in nondegenerate [G. M. Zaslavsky, Chaos in Dynamic Systems (Harwood Academic, Chur, 1985)] and degenerate [Demikhovskii, Kamenev, and Luna-Acosta, Phys. Rev. E 52, 3351 (1995)] classically chaotic systems only in the particular regions of the classical phase space, such as the center of the resonance or near the separatrix. The system under consideration is degenerate, and even an infinitely small perturbation generates in the classical phase space an infinite number of the resonant cells which are arranged in the pattern with the axial symmetry of the order 2&mgr; (where &mgr; is the resonance number). We show analytically that the Husimi functions of all Floquet states (the quantum phase space) have the same symmetry as the classical phase space. This correspondence is demonstrated numerically for the Husimi functions of the Floquet states corresponding to the motion near the elliptic stable points (centers of the classical resonance cells). The derived results are valid in the resonance approximation when the perturbation amplitude is small enough, and the stochastic layers in the classical phase space are exponentially thin. The developed approach can be used for studying a global symmetry of more complicated quantum systems with chaotic behavior. (c) 2000 American Institute of Physics.

Journal Article↗