Lipid hydroperoxide-induced apoptosis in human colonic CaCo-2 cells is associated with an early loss of cellular redox balance

Apoptosis plays a critical role in maintaining homeostasis of the intestinal epithelium. Dietary oxidants like peroxidized lipids could perturb cellular redox status and disrupt mucosal turnover. The objective of this study was to delineate the role of lipid hydroperoxide (LOOH) -induced redox shifts in intestinal apoptosis using the human colonic CaCo-2 cell. We found that subtoxic concentrations of LOOH increased CaCo-2 cell apoptosis. This LOOH-induced apoptosis was associated with a significant decrease in the ratio of reduced glutathione-to-oxidized glutathione (GSH/GSSG), which preceded DNA fragmentation by 12 to 14 h, suggesting a temporal relationship between the two events. Oxidation of GSH with the thiol oxidant diamide caused significant decreases in cellular GSH and GSH/GSSG at 15 min that correlated with the activation of caspase 3 (60 min) and cleavage of PARP (120 min), confirming a temporal link between induction of cellular redox imbalance and initiation of apoptotic cell death. These kinetic studies further reveal that oxidant-mediated early redox change (within 1 h) was a primary inciting event of the apoptotic cascade. Once initiated, the recovery of redox balance did not prevent the progression of CaCo-2 cell apoptosis to its biological end point at 24 h. Collectively, the study shows that subtoxic levels of LOOH disrupt intestinal redox homeostasis, which contributes to apoptosis. These results provide insights into the mechanism of hydroperoxide-induced mucosal turnover that have important implications for understanding oxidant-mediated genesis of gut pathology.

Dysphagia in patients with brainstem stroke: incidence and outcome

OBJECTIVE

This study was conducted to delineate the incidence and outcome of dysphagia among hospitalized patients who were referred for rehabilitation because of brainstem stroke.

DESIGN

We retrospectively reviewed the medical records of 36 patients who were admitted because of brainstem stroke. Information on the patients' clinical features, feeding status, and the results of clinical and videofluoroscopic swallowing examinations were obtained through chart review. Follow-up interviews were conducted via telephone to learn the general medical condition and feeding status of the patients 7-43 mo after hospital discharge.

RESULTS

A total of 81% of the patients had dysphagia at the time of initial clinical swallowing evaluation, which was performed 10-75 days after the onset of stroke. A total of 79% of the dysphagic individuals depended on tube feeding at the initial evaluation; 22% of all individuals could not resume oral intake at discharge. Statistical analyses revealed a significant association between poor outcome and disease involving the medulla, the presence of a wet voice during the initial swallowing test, and a delay or absence of the swallowing reflex. The incidence of aspiration pneumonia was 11%. There was a correlation between the detection of aspiration by modified barium meal videofluoroscopy and the development of aspiration pneumonia. Follow-up interviews showed that 88% of the 27 patients who were contacted had resumed full oral intake 4 mo after the onset of stroke.

CONCLUSIONS

The incidence of dysphagia was relatively high in our study population. The long-term outcome was favorable.

Influencing factors and ambulation outcome in patients with dual disabilities of hemiplegia and amputation

OBJECTIVE

To determine the ambulatory outcome and predictive factors of successful ambulation training in patients with both hemiplegia and lower extremity amputation.

DESIGN

A retrospective study.

SETTING

A rehabilitation center of a university hospital.

PATIENTS

Twenty-three patients with dual disabilities consecutively admitted to the rehabilitation center from 1984 to 1994.

MAIN OUTCOME MEASURES

Ambulatory outcome was measured using physical therapists' and physicians' notes at discharge or the last available clinical visit. Ambulation ability was graded as community and noncommunity ambulation, which included indoor ambulation and nonambulation. Several clinical features were reviewed to assess their association with ambulation outcome.

RESULTS

About two thirds of the 23 patients could be trained to be ambulatory: 10 (43.8%) achieved community ambulation and 5 (21.7%) achieved indoor ambulation. Of the clinical factors, only mental status showed a statistically significant association with good ambulation outcome (p<.05). When odds ratios were considered, several factors, including mild motor involvement, transtibial amputation, amputation before cerebrovascular accident, age younger than 60 years, and the presence of ipsilateral hemiplegia and amputation, showed trends toward association with increased ambulation achievement, although these associations were not statistically significant.

CONCLUSION

Impaired mental status seemed to be the most influential negative predictive factor of achieving community ambulation. If subjects with dual disabilities are properly selected, satisfactory results of ambulation training will be obtained.

Sonographic detection of occult fractures in the foot and ankle

PURPOSE

The purpose of this retrospective study was to determine whether high-resolution sonography can aid in the diagnosis of radiographically occult fractures in the foot and ankle.

METHODS

High-resolution sonography with a 10-MHz linear-array transducer was performed in 268 patients with foot and ankle injuries whose initial plain x-ray films were negative for fracture.

RESULTS

Twenty-four patients had occult fractures demonstrated by sonography. On sonography, the occult fractures appeared as a discontinuity of cortex echogenicity. The fractures were found at the calcaneus (n = 8), metatarsus (n = 6), talus (n = 3), navicular bone (n = 3), cuboid bone (n = 2), cuneiform bone (n = 1), and lateral malleolus (n = 1). Review of the patients' radiographs revealed tiny fractures at the sonographically identified locations in 2 patients. The first 5 patients underwent bone scans, which confirmed the presence of the fractures. The first 11 patients received follow-up sonographic examination 6 weeks after diagnosis; in all 11, an echogenic line over the previous fracture site, presumably representing callus formation, was noted.

CONCLUSIONS

Sonography-a readily available, noninvasive imaging technique-can provide important information about soft tissue injuries and cortical discontinuities in the foot and ankle area. Using this procedure, occult fractures can be identified and delineated, and costly procedures such as MRI can be avoided.

Sonographic evaluation of the posterior cruciate ligament in amputated specimens and normal subjects

The purpose of this study was to define the sonographic appearance and echogenicity of the normal posterior cruciate ligament. We examined the posterior cruciate ligament of five amputated specimens and five normal subjects using a 10 MHz linear array transducer. One K-wire was inserted into the substance of the posterior cruciate ligament of the amputated knee specimens to verify the location of the ligament on the sonogram. Various angles of insonation were used to examine the echogenicity of the posterior cruciate ligament. The results showed that the in situ posterior cruciate ligament appeared as a hypoechoic band relative to the surrounding tissue on sonograms, but it appeared hyperechoic when it was isolated and immersed in a water bath. The specific spatial orientation of the posterior cruciate ligament and anisotropy phenomenon contributed to the hypoechogenicity of the posterior cruciate ligament in situ on sonogram.

Ultrasonographic assessment of posterior heel pain

To investigate the value of ultrasonography in the diagnosis of posterior heel pain, 68 patients with normal plain x-ray findings of the posterior heel underwent ultrasonographic examination with a 10-MHz linear array probe. The findings included Achilles tendinosis (31 patients), retrocalcaneal bursitis (12), superficial Achilles bursitis (7), soft tissue mass (7), Achilles tendon rupture (4), xanthoma (3), tenosynovitis of the flexor hallucis longus tendon (2), and negative findings (2). Sixteen of these patients underwent surgery after ultrasonographic examination. The surgical diagnoses were consistent with the ultrasonographic diagnoses in all cases. With high-resolution ultrasonography, pathologic conditions of the posterior heel can be readily differentiated.

Atomic force microscopy used for the surface characterization of microcapsule immunoisolation devices

The surface morphology of the microcapsule used as a bioartificial pancreas was examined by atomic force microscopy (AFM) under ambient conditions in a liquid environment. The standard contact mode was used for imaging. The capsules exhibited different morphologies and surface roughness depending on the composition of the cation solution: namely, the mole ratio of antigelling and gelling cations [Na+]/[Ca2+]. Surface roughness parameters obtained by AFM measurements provide quantitative information on the surface properties of the capsular membrane. In this respect, AFM can be considered a valuable technique complementary to optical microscopy in providing feedback for capsule optimization.

Treatment of emotionalism with fluoxetine during rehabilitation

Emotionalism (emotional lability) is a common but distressing phenomenon that occurs frequently in individuals suffering cerebral vascular accidents and other brain diseases. Patients with emotionalism sometimes embarrass their families and themselves, becoming socially disabled despite normal physical function. At its worst, emotionalism interferes with rehabilitation programs, delays progress and sometimes makes these programs impossible. This paper reports the effect of fluoxetine in treating three patients with persistent emotionalism (2 cases following cerebrovascular accidents, 1 case following encephalitis). All 3 patients demonstrated dramatic improvement in emotionalism within 6 days of treatment. The severity, frequency and duration of each episode were reduced greatly. The treatment improved the effectiveness of the rehabilitation program, relieved patient and family embarrassment, and enabled patients to resume rapidly their previous lifestyle patterns. All patients reached the functional goals planned prior to the onset of rehabilitation. We conclude that fluoxetine is highly effective in treating the symptoms of emotionalism in all patients, and allows for recovery of both physical and social function.

Ventilatory and mouth occlusion pressure responses to hypercapnia in chronic tetraplegia

OBJECTIVE

To compare the ventilatory response to hypercapnia and the mouth occlusion pressure measured at 0.1 second following inspiration (P0.1) in hypercapnia between chronic tetraplegic and normal subjects.

DESIGN

A case-control study with an uneven sample size for the study of clinical disorders.

SETTING

Patients were recruited from the outpatient clinic of a rehabilitation department.

PARTICIPANTS

Seven normal men and 9 men with tetraplegia who had cervical cord injuries (C5-C8), with a mean injury duration of 9.7 yrs.

INTERVENTIONS

Pulmonary function tests were performed during resting, whereas minute ventilation (VE) and P0.1 were measured during CO2 rebreathing.

RESULTS

The maximal voluntary ventilation (MVV), vital capacity (VC), and maximal respiratory muscle strength in the tetraplegic subjects were significantly less than in the normal subjects. Both the ventilatory and P0.1 responses to hypercapnia were significantly reduced in tetraplegic as compared with normal subjects, but the reductions were eliminated by normalizing with maximal ventilatory performance (MVV or VC) and maximal inspiratory muscle strength (PImax), respectively.

CONCLUSIONS

Chronic tetraplegic persons have diminished ventilatory and P0.1 responses to hypercapnia. Respiratory muscle weakness may be a primary factor contributing to the diminished ventilatory response observed in these patients.

Sonographic detection of a stitch abscess

A 28-year-old man with a ruptured right Achilles tendon underwent primary end-to-end suture immediately after injury. Painful swelling developed 6 months later, and a lump with discharge from a sinus was observed during physical assessment. Sonographic examination with a 10-MHz linear-array transducer demonstrated a hypoechoic mass, 8 x 6 mm, within which were 2 markedly echogenic dots. A stitch abscess was strongly suspected and was confirmed surgically.

Sonography of pigmented villonodular synovitis in the ankle joint

Pigmented villonodular synovitis is a benign proliferative disorder of the synovium that results in villous nodule formation in joints, tendon sheaths, and bursae. We present a case of pigmented villonodular synovitis of the ankle joint that was diagnosed by sonography with color Doppler imaging. The sonograms revealed hypoechoic synovial proliferation, and hypervascularity was visible on color Doppler images. The differential diagnosis of a synovial thickening or mass is also discussed.

New technologies for bioartificial organs

Each year several hundred thousand Americans die because of organ failure. Organ transplantations have achieved remarkable success, but the source of human organs is limited. Only a small portion of patients can benefit annually from this method of treatment. Immunoisolated living cells as bioartificial organs can be transplanted into humans without the need for immunosuppression and its accompanying side effects. Immunoisolation allows cells from nonhuman species to be used, thereby overcoming the limited supply of human cells available for encapsulation, and the capsule can serve as an ideal cage to keep animal viruses from contacting the human host. To achieve this promise, we have incorporated the pore size distribution into a new design of capsule for the immunoisolation of living cells. In this model the capsule wall is thicker and the pores are bigger than in the current systems. The larger pores will allow the immune system to enter the membrane, and the smaller pores inside the membrane will act as the traps to prevent or delay most of the immune system from passing all the way through to the inner volume of the capsule where the living cells reside. Limited animal studies have supported the advantages of this new entrapment model over the current model. Systematic studies to determine optimal capsule design for human transplantation are now feasible.

Permeability assessment of capsules for islet transplantation

Despite considerable progress in the development of immunoisolation devices, the optimal permeability of such devices is not known. This limitation stems partly from deficits in knowledge about which molecules should be allowed to traverse the semipermeable membrane and which molecules should be excluded, and also partly from experimental obstacles that have prevented a systematic study of permeability. To determine the optimal permeability of immunoisolation devices, we have created a series of microcapsules (800 microM diameter) that span a broad range of molecular exclusion limits yet are identical in wall thickness and chemical composition. Capsule permeability was precisely defined by two complementary methods--size exclusion chromatography (SEC) and a newly developed methodology to assess permeability of biologically relevant proteins. The entry of interleukin-1 beta-125I was significantly delayed, but not prevented, when the capsule exclusion limit was decreased from 230 kD to 3.2 kD, as determined by SEC with dextran standards. The influx of IgG was as predicted, based on the viscosity radius R eta of IgG and the capsule exclusion limit defined by SEC. Glucose-stimulated insulin secretion by encapsulated pancreatic islets did not differ as capsule permeability was decreased from a molecular exclusion limit of 230 kD to 120 kD. These studies should assist in the design of immunoisolation devices by defining the permeability optimal for cell function and also should be applicable to any cell type or immunoisolation device.

Purification of polymers used for fabrication of an immunoisolation barrier

A multistep extraction procedure has been tested for purification of natural and semi-synthetic polymers used for fabrication of an immunoisolation barrier for implanting animal cells. This procedure, originally described by Klock et al. for alginates, has been adapted for other gelling polymers to remove pyrogens (endotoxins) and mitogens. Several other steps have also been tested, resulting in a new and simple procedure for polymer purification, giving satisfactory levels of contamination. Endotoxin levels have been quantified by means of chromogenic and gelclot LAL methods. A simple calculation of the endotoxin permissible levels shows that the quality of purified polymers exceeds FDA specifications for implantable polymers.

Interleukin 7 induces TCR gene rearrangement in adult marrow-resident murine precursor T cells

Rearrangement of the T cell antigen receptor genes is a complex, highly regulated process. To gain a better understanding of the extracellular factors involved in the regulation of TCR beta and gamma gene rearrangement in adult murine bone marrow-resident precursor T cells, several cytokines were tested for their ability to induce gene recombination. A selected population of C58/J bone marrow cells (Thy 1(low), CD3, CD8, B220) that is enriched for pre-T cell activity was propagated in vitro in medium supplemented with IL-3 and mast cell growth factor (MGF, also referred to as stem cell factor, Steele factor and c-kit ligand). These cytokines were required for the maintenance of pre-T cell activity in culture, but had no effect on TCR gene expression. Several additional cytokines were added to the culture medium. Of all those tested, only IL-7 induced complete rearrangement of the TCR gamma locus. Complete rearrangement of the TCR beta locus was not induced under any of the culture conditions analysed here. The bone marrow cells cultured in IL-3, MGF and IL-7 did not begin to express mature T cell proteins and maintained their in vivo progenitor potential. Furthermore, IL-7 cultured bone marrow cells were capable of differentiation in vivo into all phenotypic subpopulations of T cells, without an apparent bias toward the gammadelta lineage. The data presented here suggest that TCR gamma gene rearrangement in adult pre-T cells is regulated by IL-7, but that the TCR beta locus requires additional or alternative signals for the induction of complete rearrangement.

Ultrasonographic examination of the posterior tibial tendon

The posterior tibial tendons (PTTs) of 16 patients with PTT dysfunction and 10 age-matched healthy subjects were examined ultrasonographically, using a 10-MHz linear-array transducer. Normal PTTs appeared hyperechoic (more echogenic) and oval, with an average diameter of 7.8 mm x 3.7 mm at the medial malleolar level. Degenerated PTTs appeared hypoechoic (less echogenic) and swollen (9.8 mm x 5.0 mm). Peritendinitis presented as a hypoechoic rim on the longitudinal sonogram (along the long axis of the tendon) and a "target sign" (hyperechoic central structure with a hypoechoic halo) on the transverse sonogram (at the right angle to the long axis of the tendon). Complete rupture of the PTT revealed an empty tibial groove at the level of the medial malleolus on the transverse sonogram and a wavy fibril pattern over the distal end on the longitudinal sonogram. Compared with the operative findings or the results of the magnetic resonance imaging, ultrasonography was sensitive and specific in diagnosing tenosynovitis and complete rupture of the PTT.

Pre-thymic transcription of TCR genes by adult murine bone marrow cells

In the adult mouse, the earliest thymocytes are derived from bone marrow-resident T lymphocyte precursor (pre-T) cells that immigrate to the thymus. There they undergo maturation through a series of developmental steps that include rearrangement and expression of the TCR genes, positive and negative selection, and functional maturation. Although these intrathymic processes have been extensively characterized, little is known about the T cell-specific events that take place in the bone marrow microenvironment. Of particular interest are the events surrounding transcription and rearrangement of the various TCR chains that are required for functional TCR expression. We have previously reported the transcription of incompletely rearranged TCR beta genes in pre-T cell-containing fractions of adult bone marrow. Here we demonstrate that the TCR gamma chain genes are also transcriptionally active in these cells. Like the TCR beta transcripts, TCR gamma transcripts are sterile, originating from unrearranged gamma loci. Interestingly, both RAG-1 and RAG-2 transcripts were also detected in this cell fraction, suggesting that sterile TCR transcription might be dependent upon the presence of a functional recombinase system. However, both C beta and C gamma sterile transcripts could be detected from the same bone marrow cell population isolated from RAG-1 gene deficient mice. Therefore, the expression of TCR genes can initiate at the earliest stages of T cell development, prior to exposure to the thymic microenvironment, and a functional recombinase system is not required for the production of these sterile TCR transcripts.

Clinical experience in rehabilitation of spinal cord injury associated with schizophrenia

OBJECTIVE

To identify the clinical features and rehabilitation outcomes in spinal cord injury (SCI) patients with preexisting schizophrenia.

DESIGN

A retrospective study conducted by reviewing the charts of all patients diagnosed with both SCI and schizophrenia hospitalized from 1987 throughout 1994 in 2 rehabilitation units.

SETTING

Rehabilitation wards of two hospitals in Taiwan.

PATIENTS

Seventeen traumatic SCI patients with schizophrenia, including 7 men and 10 women. Patients without neurological deficits were excluded.

INTERVENTION

All subjects received psychiatric intervention and intensive rehabilitation programs during hospitalization.

MAIN OUTCOME MEASURES

The injury pattern and psychiatric condition were described. Abilities of locomotion, management of activities of daily living, and bladder control were measured.

RESULTS

Fifteen injuries caused by a voluntary fall subsequently resulted in thoracolumbar insult. Ten incomplete paraplegics were able to ambulate with or without a device on discharge. Four subjects had poor bladder control. The outcome of self-care skills was worse in those with high level injury. Psychiatric symptoms were one of the main obstacles during rehabilitation.

CONCLUSION

Voluntary fall that caused thoracolumbar injuries was the main cause of injuries in these patients. Psychiatric symptoms were present in the majority and might hinder the prognosis of treatment. Nevertheless rehabilitation programs were found to benefit subjects after their psychiatric problems were under control.

Transcription of the TCR-beta locus initiates in adult murine bone marrow

Successful expression of the TCR beta-chain gene is a multistep process that involves: 1) initial transcription of multiple, unrearranged gene segments, 2) rearrangement of V, D, and J gene segments to form a complete beta-chain gene, and 3) transcription of the fully rearranged beta gene. All of these events have been shown to occur in the thymus, where the majority of T cell development takes place; however, the extent to which any of these events may occur prethymically has not been established. To examine prethymic TCR-beta gene expression, RNA was isolated from a precursor T cell-enriched population (Thy 1low CD3-) of C58/J mouse bone marrow, and analyzed by reverse transcriptase-PCR. A transcript containing TCR-beta constant (C) region sequences but not variable (V) region sequences was amplified, suggesting that an unrearranged TCR-beta gene locus is transcriptionally active in this bone marrow population. The same product was detected in Thy 1+ CD3- bone marrow cells from nude mice, indicating that the thymic microenvironment is not necessary for initiation of TCR-beta gene transcription. This C beta transcript is not confined to pre-B cells, as it was identified in RNA isolated from Thy 1low CD3- B220- bone marrow cells. Germline V beta transcripts were also detected in RNA from this bone marrow population. Furthermore, Sca-1+ Lin- and Sca-1+ Lin+ bone marrow populations from both C58/J mice and nude mice also expressed the C beta transcript. DNA-PCR analyses with D beta-J beta primer sets revealed that partial rearrangement of the beta locus had occurred in all bone marrow populations analyzed. These data suggest that both transcription and partial rearrangement of the TCR-beta locus can initiate in bone marrow cells of adult mice, before exposure of these cells to the thymus.

Transcription of the TCR-beta locus initiates in adult murine bone marrow

Successful expression of the TCR beta-chain gene is a multistep process that involves: 1) initial transcription of multiple, unrearranged gene segments, 2) rearrangement of V, D, and J gene segments to form a complete beta-chain gene, and 3) transcription of the fully rearranged beta gene. All of these events have been shown to occur in the thymus, where the majority of T cell development takes place; however, the extent to which any of these events may occur prethymically has not been established. To examine prethymic TCR-beta gene expression, RNA was isolated from a precursor T cell-enriched population (Thy 1low CD3-) of C58/J mouse bone marrow, and analyzed by reverse transcriptase-PCR. A transcript containing TCR-beta constant (C) region sequences but not variable (V) region sequences was amplified, suggesting that an unrearranged TCR-beta gene locus is transcriptionally active in this bone marrow population. The same product was detected in Thy 1+ CD3- bone marrow cells from nude mice, indicating that the thymic microenvironment is not necessary for initiation of TCR-beta gene transcription. This C beta transcript is not confined to pre-B cells, as it was identified in RNA isolated from Thy 1low CD3- B220- bone marrow cells. Germline V beta transcripts were also detected in RNA from this bone marrow population. Furthermore, Sca-1+ Lin- and Sca-1+ Lin+ bone marrow populations from both C58/J mice and nude mice also expressed the C beta transcript. DNA-PCR analyses with D beta-J beta primer sets revealed that partial rearrangement of the beta locus had occurred in all bone marrow populations analyzed. These data suggest that both transcription and partial rearrangement of the TCR-beta locus can initiate in bone marrow cells of adult mice, before exposure of these cells to the thymus.

Noninvasive long-term ventilatory support for individuals with spinal muscular atrophy and functional bulbar musculature

Ten individuals with spinal muscular atrophy (SMA) and chronic ventilatory insufficiency were trained in the use of assisted coughing techniques and received intermittent positive pressure ventilation (IPPV) via oral and/or nasal interfaces for a mean of 5.3 (range = 1 to 17) years. During this time they had significantly fewer respiratory complications than before introduction of noninvasive respiratory muscle aids despite the fact that 6 of the 10 went on to require more than 20 hours per day of ventilator use with less than 2 hours of ventilator-free breathing time (VFBT). All except two noninvasive IPPV users had vital capacities (VCs) less than 13% of predicted normal. They could, however, communicate verbally and take nutrition by mouth. All of the patients remained in the community. Five patients were gainfully employed and four were in school. We conclude that noninvasive respiratory muscle aids including noninvasive IPPV and assisted coughing techniques are effective and practical alternatives to tracheostomy for SMA patients with ventilatory failure but functional bulbar musculature.

[Barium-pudding: a new medium for videofluoroscopic examination]

The evaluation of swallowing function is crucial in the management of dysphagic patients. It includes clinical assessment and laboratory tests that consist of fiberoptic endoscopic examination of swallowing (FEES) and videofluoroscopic examination. The "modified barium swallow" has been regarded as the standard procedure of videofluoroscopic examination since its introduction in 1983. The technique enables the entire process of deglutition to be observed with the benefits of safety, easily performance, and information. However, pitfalls developed in patients with pseudobulbar paralysis. Discrepancy always occurs between barium meals and real food and the refusal of swallow and misswallowing to the airway in videofluoroscopic examination sometimes occurs because of the unsatisfactory taste of barium meal. All these things make the procedure impractical and inaccurate. We developed a barium sulfate pudding that is better tasting, similar to real food as a pudding, is adequate to visualise on videofluoroscopic examination, and has the ability to represent the patient's capacity to swallow solid food. We present a case of hypoxic encephalopathy where the patient was considered to be in danger of aspiration when swallowing any consistency of foods. Barium-pudding study showed the patient had the ability to eat solid food with safety. We removed her nasogastric tube following barium-pudding assessment and successfully restored her oral feeding function within 2 weeks. Barium-Pudding is a better medium of videofluoroscopic examination by which to evaluate the swallowing function of solid food than Barium paste in patient, who have disturbed swallowing.

[General introduction to the clinical application of non-invasive respiratory aids]

Intermittent positive pressure ventilation via tracheostomy has been the most common method of providing ventilatory support for patients with respiratory failure since the late 1950s. It is the standard procedure for individuals who suffer from acute respiratory failure, impaired consciousness, and severe restrictive lung disease. However, numerous adverse complications from these invasive techniques have been reported in those who are long-term ventilator users. This paper describes the evolution and current application of non-invasive respiratory aids in both acute and long-term settings. The respiratory function can be aided by applying forces to the body or intermittent pressure to the air ways. The devices are negative pressure body ventilators which act on the body by creating negative pressure around the thorax and abdomen such devices effectively maintain the ventilation of individuals with respiratory failure, but have the shortcomings of bulkiness, high expense, and limitation on the users' activities. The non-invasive positive pressure ventilator applies intermittent pressure directly to the airway by a non-invasive interface; namely mouthpiece, nasal, or face masks. In this way, it can prevent patients from requiring either tracheostomy or endotracheal tube, but is not effective enough to ventilate patients with markedly decreased lung compliance because the high airway resistance provides air leakage from the non-invasive interface. Non-invasive respiratory aids should be the first choice to maintain ventilation for patients with respiratory failure secondary to neuromuscular disorder, because of their benefits of easy application, satisfactory results, fewer complications and early active rehabilitation. Increased understanding of non-invasive respiratory aids should assist in the management of patients with chronic respiratory failure.

[Clinical application of the ice water test in evaluation of neurogenic bladder dysfunction]

Ice water test (IWT) and cystometrography (CMG) were performed on 51 in patients with spinal cord injuries (SCI) to evaluate the sensitivity and specificity of the IWT in detecting detrusor reflex. A three-step grading system as established by Balmaseda et al was applied to determine the presence of detrusor activity on IWT. The test was considered 3+ when the catheter was expelled from the bladder within one minute following instillation of 90 mL of ice water; a 2+ test indicated voiding around the catheter after instillation of 90 mL of ice water; and a 1+ IWT was defined as voiding around the catheter or expelling the catheter after instilling another 210 mL of ice water into the bladder. The results showed that the sensitivity of IWT in detecting the presence of detrusor reflex in patients with neurogenic bladder dysfunction was 96% and the specificity was 79%. Among the four patients having false positive IWT, three of them were diagnosed with poor-compliance bladders. One patient with false negative IWT was found to have severe detrusor-sphincter dyssynergy. There was a significant difference in the strength of detrusor activity among the patients with 3+ IWT, with 2+ IWT, and with 1+ IWT. IWT is a useful technique to predict the existence of detrusor reflex in SCI patients. Its use as a supplement method to cystometrogram could be helpful in the bedside evaluation of patients with neurogenic bladder dysfunction.

Survival of individuals with spinal muscular atrophy on ventilatory support

Six ventilator-assisted individuals (VAIs) with spinal muscular atrophy (SMA) are described. All six survived by using intermittent positive pressure ventilation via an indwelling tracheostomy for a mean of 11.7 +/- 17.7 yr despite frequent episodes of mucus plugging and pneumonia. Four of the VAIs also received all nutrition via indwelling gastrostomy tubes because of severe bulbar muscle weakness. Four VAIs used tracheostomy intermittent positive pressure ventilation with their tracheostomy cuffs deflated and could communicate verbally. Five of the six VAIs remained institutionalized from the onset of ventilatory use. Two SMA VAIs survived for 15 and 4 yr, respectively, despite need for ventilatory support since early infancy. All four SMA VAIs who could communicate remained socially active and one, gainfully employed. We conclude that for patients with advanced SMA markedly prolonged survival is possible with ventilatory assistance despite severe respiratory and bulbar muscle dysfunction.