Dysphagia caused by neurologic deficits

This article provides a brief review of the neurophysiology behind the normal swallow. The examination and work-up of a patient with dysphagia is then detailed. Finally, the major neurologic conditions associated with dysphagia are considered.

Antineutrophil cytoplasmic antibody (ANCA)-positive cutaneous leucocytoclastic vasculitis associated with antithyroid therapy in Graves' disease

Presented is a case of a 27-year-old male with Graves' disease on long-term propylthiouracil treatment who, when changed to carbimazole, rapidly developed a petechial and purpuric eruption on the legs, which subsequently flared on treatment with radioiodine. The clinical diagnosis of leucocytoclastic vasculitis was confirmed on skin biopsy. High-titre antineutrophil cytoplasmic antibodies in a perinuclear pattern (P-ANCA) were identified. No anti-myeloperoxidase activity was noted; therefore, the P-ANCA were classified in the atypical group. The target antigens, as determined by enzyme-linked immunosorbent assay, were lysozyme, lactoferrin and bactericidal/permeability increasing protein. Propylthiouracil and carbimazole are chemically related antithyroid drugs. There are reports of typical and atypical P-ANCA-positive cutaneous vasculitis due to propylthiouracil. Cutaneous vasculitis associated with atypical P-ANCA has not been noted previously to be temporally related to carbimazole use. The consideration of thionamides as possible aetiological agents in cases of P-ANCA-positive drug-induced vasculitis is suggested.

The location of the intervertebral lumbar disc on the posterior aspect of the spine

BACKGROUND

Epidural fibrosis or scar formation is considered one cause of failed lumbar discectomy. Avoidance of unnecessary bony resection of the lamina may prevent or decrease postoperative scar formation. The knowledge of the precise location of the projection of the lumbar disc may also facilitate surgery and decrease patient morbidity. No studies exist regarding the projection of the lumbar disc on the posterior aspect of the lumbar spine.

METHODS

Thirty-six whole lumbar spine specimens from L1 to L5 (180 lumbar vertebrae) and sacra were used for this study. Anatomic evaluation included the distance between the superior border of the vertebral body (inferior border of the intervertebral disc) and the superiormost margin of the lumbar lamina, and the distance between the inferior border of the vertebral body (superior border of the intervertebral disc) and the inferiormost margin of the lumbar lamina. The width of the interlaminar space was also measured.

RESULTS

The data showed that the level of the superior margin of the lamina was consistently inferior to the superior border of the corresponding vertebral body from L1 to S1. This distance for both sexes ranged from 10 to 11 mm for L1-L5 and 14 mm for S1. The level of the inferior margin of the lamina varied from 3 mm inferior to 9 mm superior to the inferior border of the corresponding vertebral body for L1-L5. The width of the interlaminar space averaged from 16.8 mm for L1 to 31.0 mm for L5.

CONCLUSIONS

This study suggests that the superior margin of the lamina represents a consistent, useful landmark in determining the location of the lumbar disc on the posterior aspect of the spine. The relationship between the inferior margins of the lamina and the vertebral body is not consistent.

Rhamnolipid (biosurfactant) effects on cell aggregation and biodegradation of residual hexadecane under saturated flow conditions

The objective of this research was to evaluate the effect of low concentrations of a rhamnolipid biosurfactant on the in situ biodegradation of hydrocarbon entrapped in a porous matrix. Experiments were performed with sand-packed columns under saturated flow conditions with hexadecane as a model hydrocarbon. Application of biosurfactant concentrations greater than the CMC (the concentration at which the surfactant molecules spontaneously form micelles or vesicles [0.03 mM]) resulted primarily in the mobilization of hexadecane entrapped within the sand matrix. In contrast, application of biosurfactant concentrations less than the CMC enhanced the in situ mineralization of entrapped hexadecane; however, this effect was dependent on the choice of bacterial isolate. The two Pseudomonas isolates tested, R4 and ATCC 15524, were used because they exhibit different patterns of biodegradation of hexadecane, and they also differed in their physical response to rhamnolipid addition. ATCC 15524 cells formed extensive multicell aggregates in the presence of rhamnolipid while R4 cells were unaffected. This behavior did not affect the ability of the biosurfactant to enhance the biodegradation of hexadecane in well-mixed soil slurry systems but had a large affect on the extent of entrapped hexadecane biodegradation in the sand-packed-column system that was used in this study.

Selection and partial characterization of a Pseudomonas aeruginosa mono-rhamnolipid deficient mutant

Pseudomonas aeruginosa produces rhamnolipids which are tenso-active compounds with potential industrial and environmental applications. There are two main types of rhamnolipids produced in liquid cultures, rhamnosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate (mono-rhamnolipid) and rhamnosyl-rhamnosyl-beta-hydroxydecanoyl-beta-hydroxyd ecanoate (di-rhamnolipid). In this work we report the selective isolation of a rhamnolipid deficient mutant (IBT8), which does not accumulate mono-rhamnolipid while still producing di-rhamnolipid. IBT8 was selected after random mutagenesis with Tn501; yet, its mono-rhamnolipid deficiency was found associated neither with its Tn501 insertion nor with a possible alteration in the rhlABRI genes for rhamnosyl-transferase 1 synthesis. Different possibilities to explain IBT8 phenotype are discussed.

Goserelin acetate (Zoladex) plus endometrial ablation for dysfunctional uterine bleeding: a large randomized, double-blind study

OBJECTIVE

To confirm the advantages of goserelin prior to endometrial ablation for the treatment of dysfunctional uterine bleeding.

DESIGN

Multicenter, prospective, randomized, double-blind study.

PATIENT(S)

Cycling premenopausal women with dysfunctional uterine bleeding.

TREATMENT

Patients were randomized to goserelin or placebo (sham depot) once monthly for 2 months prior to endometrial ablation. Treatment was timed to allow surgery 6 weeks later on day 7 of the menstrual cycle.

MAIN OUTCOME MEASURE(S)

Amenorrhea rates, endometrial histology and thickness, pain and blood loss scores, and surgical parameters.

RESULT(S)

At 24 weeks after surgery, significantly more goserelin than placebo patients experienced amenorrhea (40% versus 26%). Blood loss was reduced from baseline, but not different between the groups. At surgery, mean endometrial thickness was 1.6 mm and 3.4 mm for the goserelin and placebo groups, respectively, with significantly more atrophic glands and stroma in the goserelin group. Surgery was significantly shorter (by 22%) and easier in the goserelin than in the placebo group, with a significantly lower median fluid absorption in the goserelin groups. In both groups, pain scores were reduced patient satisfaction was high (> 92%), and re-intervention rate was low (2.8%).

CONCLUSION(S)

Goserelin in combination with endometrial ablation was superior to endometrial ablation alone for the treatment of dysfunctional uterine bleeding.

Influence of a Rhamnolipid Biosurfactant on the Transport of Bacteria through a Sandy Soil

The objective of this study was to investigate the influence of an anionic rhamnolipid biosurfactant on the transport of bacterial cells through soil under saturated conditions. Three cell types with various hydrophobicities, i.e., Pseudomonas aeruginosa ATCC 9027, ATCC 27853, and ATCC 15442, were used in this study. In a series of experiments, columns packed with sterile sand were saturated with sterile artificial groundwater for 15 h, and then 3 pore volumes of (sup3)H-labeled bacterial suspensions with various rhamnolipid concentrations was pumped through the column. This was followed by 4 pore volumes of the rhamnolipid solution alone. The measured bacterial cell breakthrough curves were optimized by using an advection-dispersion transport model incorporating two-domain reversible sorption (instantaneous and rate limited) and with two first-order sink terms for irreversible adsorption. The influence of the rhamnolipid on the surface charge densities of the bacteria and the porous medium was also investigated. The results show that the rhamnolipid enhanced the transport of all cell types tested. For example, the rhamnolipid increased the recovery of the most hydrophilic strain, ATCC 9027, from 22.5 to 56.3%. Similarly, the recovery of ATCC 27853 increased from 36.8 to 49.4%, and the recovery of ATCC 15442, the most hydrophobic strain, increased from 17.7 to 40.5% in the presence of the rhamnolipid. The negative surface charge density of the porous medium was increased, while the surface charge density of the bacteria was not changed in the presence of the rhamnolipid. The model results suggest that the rhamnolipid predominantly affected irreversible adsorption of cells.

Transfection with aFGF cDNA improves wound healing

Somatic gene therapy is a potentially useful strategy for the delivery of growth factors or cytokines to enhance wound healing. Experimental excisional and incisional wounds in impaired-healing diabetic mice (db/db) were treated with aFGF and with a plasmid coding for aFGF. A eukaryotic expression plasmid composed of the Hst signal peptide sequence in-frame with the human aFGF sequence was used. Transfection of tissues was accomplished either by direct plasmid uptake or by uptake facilitated with cationic liposomes. The results show that the closure of excisional wounds was significantly accelerated (p < 0.05) by topical application of human recombinant aFGF or by transfection with the aFGF plasmid but not by vehicle or control plasmid not containing the aFGF sequence. In incisional wounds, aFGF or transfection with the plasmid significantly increased the wound-breaking strength compared to their corresponding controls (p < 0.05). Quantitative histology of the plasmid-treated incisional wound sections revealed improved wound quality. The transcription of mRNA from human aFGF cDNA in the incisional wound tissue extracts was confirmed by RT-PCR, and the expressed aFGF was detected by immune dot blot and immunohistochemistry assays. The transfection was a transient process with a peak at 9 d in db/+ (littermates of the diabetic mice) incisional wounds, at 36 d in db/db incisional wounds, and at 27 d in db/db excisional wounds. Cells transfected with human aFGF occupied up to 6.4% of the transectional area in the wound sites. Thus, aFGF gene delivery resulted in both gene expression and a functional improvement in healing.

Anatomic consideration of transpedicular screw placement in the cervical spine. An analysis of two approaches

STUDY DESIGN

This study compared the effectiveness of two transpedicular screw placement techniques: blind screw placement versus screw placement after direct determination of the superior, medial, and inferior borders of the pedicle through the opening of a "window" by the partial laminectomy and tapping technique.

OBJECTIVES

To determine if the incidence and severity of pedicle violations resulting from transpedicular screw placement could be reduced by direct determination of the superior, medial, and inferior borders of the pedicle through the opening of a "window" by partial laminectomy.

SUMMARY OF BACKGROUND DATA

Several studies regarding transpedicular screw fixation for unstable cervical spine injuries have been reported, but none has addressed the effectiveness in lowering the incidence of pedicle violation by opening a "window" by partial laminectomy for direct determination of the superior, medial, and inferior borders of the pedicle and using the tapping technique before and in planning for screw placement.

METHODS

Eight adult cadaveric cervical spines (40 vertebrae from C3 to C7) were used for this study. Two groups were formed according to screw placement techniques. The first group was composed of 38 blinded transpedicular screw placements. The second group was composed of 40 screw placements using the partial laminectomy and tapping technique. After transpedicular screw placement, all specimens were evaluated radiographically and visually for violation of the pedicle.

RESULTS

A decrease in the incidence and severity of pedicle violation was seen in the second group with opening of the lamina and tapping technique compared with the blind screw placement group. However, the percentage of screws found to violate the pedicle with the opening of the lamina and tapping technique still was relatively high.

CONCLUSIONS

Transpedicular screw placement in the cervical spine is difficult, and a high percentage of violations of the pedicle wall occur. This technique should not be used routinely.

Management of oral-pharyngeal dysphagia symptoms in amyotrophic lateral sclerosis

Oral and pharyngeal dysphagia is a common symptom in patients with amyotrophic lateral sclerosis (ALS) and is the result of a progressive loss of function in bulbar and respiratory muscles. Clinicians involved in the management of ALS patients should be familiar with the common clinical findings and the usual patterns of temporal progression. The prevention of secondary complications, such as nutritional deficiency and dehydration that compound the deteriorating effects of the disease, requires careful monitoring of each patient's functional status and timely intervention with appropriate management techniques.

Effect of Rhamnolipid (Biosurfactant) Structure on Solubilization and Biodegradation of n-Alkanes

A study to quantify the effect of rhamnolipid biosurfactant structure on the degradation of alkanes by a variety of Pseudomonas isolates was conducted. Two dirhamnolipids were studied, a methyl ester form (dR-Me) and an acid form (dR-A). These rhamnolipids have different properties with respect to interfacial tension, solubility, and charge. For example, the interfacial tension between hexadecane and water was decreased to <0.1 dyne/cm by the dR-Me but was only decreased to 5 dyne/cm by the dR-A. Solubilization and biodegradation of two alkanes in different physical states, liquid and solid, were determined at dirhamnolipid concentrations ranging from 0.01 to 0.1 mM (7 to 70 mg/liter). The dR-Me markedly enhanced hexadecane (liquid) and octadecane (solid) degradation by seven different Pseudomonas strains. For an eighth strain tested, which exhibited extremely high cell surface hydrophobicity, hexadecane degradation was enhanced but octadecane degradation was inhibited. The dR-A also enhanced hexadecane degradation by all degraders but did so more modestly than the dR-Me. For octadecane, the dR-A only enhanced degradation by strains with low cell surface hydrophobicity.

Biosurfactant-facilitated remediation of metal-contaminated soils

Bioremediation of metal-contaminated wastestreams has been successfully demonstrated. Normally, whole cells or microbial exopolymers are used to concentrate and/or precipitate metals in the wastestream to aid in metal removal. Analogous remediation of metal-contaminated soils is more complex because microbial cells or large exopolymers do not move freely through the soil. The use of microbially produced surfactants (biosurfactants) is an alternative with potential for remediation of metal-contaminated soils. The distinct advantage of biosurfactants over whole cells or exopolymers is their small size, generally biosurfactant molecular weights are less than 1500. A second advantage is that biosurfactants have a wide variety of chemical structures that may show different metal selectivities and thus, metal removal efficiencies. A review of the literature shows that complexation capacities of several bacterial exopolymers was similar to the complexation capacity of a rhamnolipid biosurfactant produced by Pseudomonas aeruginosa ATCC 9027.

Application of an electrocardiographic inverse solution to localize ischemia during coronary angioplasty

Localization of Ischemia. This study demonstrates the utility of an electrocardiographic inverse solution, coupled with body surface potential mapping (BSPM), in localizing acute ischemia in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). PTCA balloon inflations produce complete occlusion and acute transient ischemia, which can be detected electrocardiographically with BSPM. Comparisons between maps recorded both during and before the inflation of the PTCA balloon allow patient- and artery-specific characterizations of the resulting ischemia. Knowledge of the patient's coronary anatomy and the location of the occlusion site by coronary angiography permit an estimation based on cardiac hemodynamics of the region of myocardium most likely to suffer from PTCA-induced ischemia. Electrocardiographic inverse solutions provide a means of predicting cardiac potentials from body surface maps. In this study, we describe an inverse solution we have developed to localize the transient ischemia produced by PTCA. To validate the procedure, we compared the locations of predicted ischemia in seven patients with a qualitative estimate of the perfusion region based on fluoroscopic examination of each patient's coronary anatomy and PTCA balloon location. In each case, the region of ischemia predicted by the model included the perfusion zone determined fluoroscopically. These results suggest that electrical changes induced by acute ischemia can be localized with an electrocardiographic inverse solution.

Treatment efficacy for adults with oropharyngeal dysphagia

Over the last 10 years, the literature in the area of oropharyngeal dysphagia has focused on treatment techniques for specific medical conditions and the documentation of treatment efficacy. Increasingly, there has been multidisciplinary involvement in the study of swallowing physiology and dysphagia. Investigators have used a wide range of technologies in quantifying changes in swallowing physiology as a result of imposed therapeutic adjustments and maneuvers. Group studies and single case design investigations have attempted to address the question of treatment efficacy. This article addresses the status of clinical treatment and the future needs for research.

Behavioral treatment for adults with oropharyngeal dysphagia

Oropharyngeal dysphagia has been treated by various professionals for many years, with increasingly more attention paid to this disorder by speech-language pathologists in the past decade. There has been a gradual change in emphasis in the literature, from early anecdotal accounts to more scientific, controlled studies that have tested the outcomes and effectiveness of certain techniques or programs. This article reviews the literature in the area of behavioral treatment for oropharyngeal dysphagia, with a critical look at the current state of knowledge. General treatment programs and techniques developed to facilitate or compensate for specific swallowing disorders are summarized.

Effect of a Pseudomonas rhamnolipid biosurfactant on cell hydrophobicity and biodegradation of octadecane

In this study, the effect of a purified rhamnolipid biosurfactant on the hydrophobicity of octadecane-degrading cells was investigated to determine whether differences in rates of octadecane biodegradation resulting from the addition of rhamnolipid to four strains of Pseudomonas aeruginosa could be related to measured differences in hydrophobicity. Cell hydrophobicity was determined by a modified bacterial adherence to hydrocarbon (BATH) assay. Bacterial adherence to hydrocarbon quantitates the preference of cell surfaces for the aqueous phase or the aqueous-hexadecane interface in a two-phase system of water and hexadecane. On the basis of octadecane biodegradation in the absence of rhamnolipid, the four bacterial strains were divided into two groups: the fast degraders (ATCC 15442 and ATCC 27853), which had high cell hydrophobicities (74 and 55% adherence to hexadecane, respectively), and the slow degraders (ATCC 9027 and NRRL 3198), which had low cell hydrophobicities (27 and 40%, respectively). Although in all cases rhamnolipid increased the aqueous dispersion of octadecane at least 10(4)-fold, at low rhamnolipid concentrations (0.6 mM), biodegradation by all four strains was initially inhibited for at least 100 h relative to controls. At high rhamnolipid concentrations (6 mM), biodegradation by the fast degraders was slightly inhibited relative to controls, but the biodegradation by the slow degraders was enhanced relative to controls. Measurement of cell hydrophobicity showed that rhamnolipids increased the cell hydrophobicity of the slow degraders but had no effect on the cell hydrophobicity of the fast degraders. The rate at which the cells became hydrophobic was found to depend on the rhamnolipid concentration and was directly related to the rate of octadecane biodegradation.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimal imaging techniques for locating leaflets after escape from prosthetic heart valves

The authors report two cases of leaflets escaping from an Edwards-Duromedics bileaflet prosthetic heart valve (Baxter-Edwards Division, Baxter Healthcare Corp., Irvine, Calif.). Several imaging techniques were used in attempts to locate the leaflets. Only computed tomography (CT) led to conclusive results. Because progressive extrusion through the arterial wall was documented surgically in these cases, the authors recommend that CT be performed as early as possible after a leaflet escapes, even in asymptomatic patients. Extrusion through the arterial wall precludes percutaneous intravascular movement or retrieval of escaped leaflets.