The effects of one-hour wear of high-Dk soft contact lenses on corneal pH and epithelial permeability

PURPOSE

Previous studies have shown that 1-hour closed-eye contact lens wear with a low-Dk lens causes a significant reduction in corneal pH and an increase in epithelial permeability. In the present study, we evaluated the effects of super-high-Dk/t soft lenses on corneal epithelial barrier function and stromal pH.

METHODS

Corneal thickness was measured by optical pachometry, while epithelial permeability and stromal pH were measured by fluorophotometry. A paired-eye design was used in which one eye was randomly allocated to wear a high-oxygen-permeable soft lens (CIBAVision Focus/NIGHT & DAY (Dk/t= 175) while the other eye did not wear a lens.

RESULTS

After 1-hour closed-eye lens wear, neither the difference in corneal swelling (P = 0.206) nor the permeability (P = 0.055) between both eyes was significantly different. The mean pH values under open-eye conditions were 7.66 vs. 7.57 for the treatment and control eyes, respectively (P = 0.082), dropping to 7.27 vs. 7.25 after 1-hour eye closure (P = 0.283).

CONCLUSIONS

Although our results are limited to a 1-hour observation period, they do provide evidence that high-Dk materials may eliminate corneal acidosis and reduced epithelial barrier function that accompany closed-eye contact lens wear with lower-Dk soft lens materials.

Altered PTEN expression as a diagnostic marker for the earliest endometrial precancers

BACKGROUND

PTEN tumor suppressor gene mutations are the most frequent genetic lesions in endometrial adenocarcinomas of the endometrioid subtype. Testing the hypothesis that altered PTEN function precedes the appearance of endometrial adenocarcinoma has been difficult, however, partly because of uncertainties in precancer diagnosis.

METHODS

Two series of endometrial cancer and precancer (endometrial intraepithelial neoplasia, as diagnosed by computerized morphometric analysis) tissue samples were studied, one for PTEN mutations by the use of denaturing gradient gel electrophoresis and another for PTEN protein expression by immunohistochemistry. Endometria altered by high estrogen levels that are unopposed by progestins-conditions known to increase cancer risk-were also studied by immunohistochemistry. Fisher's exact test was used for statistical analysis.

RESULTS

The PTEN mutation rate was 83% (25 of 30) in endometrioid endometrial adenocarcinomas and 55% (16 of 29) in precancers, and the difference in number of mutations was statistically significant (two-sided P =.025). No normal endometria showed PTEN mutations. Although most precancers and cancers had a mutation in only one PTEN allele, endometrioid endometrial adenocarcinomas showed complete loss of PTEN protein expression in 61% (20 of 33) of cases, and 97% (32 of 33) showed at least some diminution in expression. Cancers and most precancers exhibited contiguous groups of PTEN-negative glands, while endometria altered by unopposed estrogens showed isolated PTEN-negative glands.

CONCLUSIONS

Loss of PTEN function by mutational or other mechanisms is an early event in endometrial tumorigenesis that may occur in response to known endocrine risk factors and offers an informative immunohistochemical biomarker for premalignant disease. Individual PTEN-negative glands in estrogen-exposed endometria are the earliest recognizable stage of endometrial carcinogenesis. Proliferation into dense clusters that form discrete premalignant lesions follows.

Resistive inspiratory muscle training: its effectiveness in patients with acute complete cervical cord injury

OBJECTIVE

To evaluate if resistive inspiratory muscle training (RIMT) can improve lung function in patients with complete tetraplegia within half a year after trauma.

DESIGN

A prospective study. The experimental patients received training with a Diemolding Healthcare Division inspiratory muscle trainer for 15 to 20 minutes per session, twice per day, 7 days a week for 6 weeks.

SETTING

Hospital-based rehabilitation units.

PATIENTS

Twenty patients who were in their first 6 months of complete cervical cord injury were randomly enrolled into RIMT (10 patients) and control (10 patients) groups.

MAIN OUTCOME MEASURE

Spirometry, lung volume test, maximal inspiratory pressure, maximal expiratory pressure, and modified Borg scale measurements at rest were performed before training and at the end of 6 weeks of training.

RESULTS

Most of the pulmonary parameters showed statistically significant improvements within the RIMT and control groups, but the improvements were greater in the RIMT group. In addition, the improvements in total lung capacity, total lung capacity predicted percentage, vital capacity, minute ventilation, forced expiratory volume in 1 second predicted percentage, and the resting Borg scale in the RIMT group showed significantly greater improvement.

CONCLUSION

RIMT can improve ventilatory function, respiratory endurance, and the perceived difficulty of breathing in patients with complete cervical spinal cord injury within half a year after trauma.

Changes in endometrial PTEN expression throughout the human menstrual cycle

Frequent mutation of the PTEN tumor suppressor gene in endometrial adenocarcinoma has led to the prediction that its product, a phosphatase that regulates the cell cycle, apoptosis, and possibly cell adhesion, is functionally active within normal endometrial tissues. We examined PTEN expression in normal human endometrium during response to changing physiological levels of steroid hormones. PTEN ribonucleic acid levels, assessed by RT-PCR, increase severalfold in secretory compared to proliferative endometrium. This suggested that progesterone, a known antineoplastic factor for endometrial adenocarcinoma, increases PTEN levels. Immunohistochemistry with an anti-PTEN monoclonal antibody displayed a complex pattern of coordinate stromal and epithelial expression. Early in the menstrual cycle under the dominant influence of estrogens, the proliferative endometrium shows ubiquitous cytoplasmic and nuclear PTEN expression. After 3-4 days of progesterone exposure, glandular epithelium of early secretory endometrium maintains cytoplasmic PTEN protein in an apical distribution offset by expanding PTEN-free basal secretory vacuoles. By the midsecretory phase, epithelial PTEN is exhausted, but increases dramatically in the cytoplasm of stromal cells undergoing decidual change. We conclude that stromal and epithelial compartments contribute to the hormone-driven changes in endometrial PTEN expression and infer that abnormal hormonal conditions may, in turn, disrupt normal patterns of PTEN expression in this tissue.

Calcium and magnesium in drinking water and risk of death from prostate cancer

The possible association between the increased risk of prostate cancer and the levels of calcium and magnesium in drinking water from municipal supplies was investigated in a matched cancer case-control study in Taiwan. All eligible prostate-cancer deaths (682 cases) of Taiwan residents from 1987 through 1993 were compared with deaths from other causes (682 controls). The levels of calcium and magnesium in the drinking water of these residents were also determined. Data on calcium and magnesium levels in drinking water throughout Taiwan were obtained from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes, and the controls were pair-matched to the cases by year of birth and death. The adjusted odds ratios for prostate cancer death for those with higher magnesium levels in their drinking water, as compared to the lowest tertile, were 0.73 (95% CI = 0.51-1.03) and 0.64 (95% CI = 0.43-0.96), respectively. The adjusted odd ratios for the relationship between calcium levels in drinking water and prostate cancer were not statistically significant. The results of the present study show that there may be a significant protective effect of magnesium intake from drinking water and other dietary sources against the risk of prostate cancer development.

Novel effects of gossypol, a chemical contraceptive in man: mobilization of internal Ca(2+) and activation of external Ca(2+) entry in intact cells

The effect of gossypol on Ca(2+) signaling in Madin Darby canine kidney (MDCK) cells was investigated by using fura-2 as a Ca(2+) probe. Gossypol evoked a rise in cytosolic free Ca(2+) levels ([Ca(2+)](i)) concentration-dependently between 2 and 20 microM. The response was decreased by external Ca(2+) removal. In Ca(2+)-free medium pretreatment with gossypol nearly abolished the [Ca(2+)](i) increase induced by carbonylcyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler, and thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2+) pump; but pretreatment with CCCP and thapsigargin only partly inhibited gossypol-induced Ca(2+) release. Addition of 3 mM Ca(2+) induced a [Ca(2+)](i) increase after pretreatment with 5 microM gossypol in Ca(2+)-free medium. This Ca(2+) entry was decreased by 25 microM econazole, 50 microM SKF96365 and 40 microM aristolochic acid (a phospholipase A(2) inhibitor). Pretreatment with aristolochic acid inhibited 5 microM gossypol-induced internal Ca(2+) release by 55%, but suppression of phospholipase C with 2 microM 1-(6-((17beta-3-methoxyestra-1,3, 5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) had no effect. Gossypol (5 microM) also increased [Ca(2+)](i) in human bladder cancer cells and neutrophils. Collectively, we have found that gossypol increased [Ca(2+)](i) in MDCK cells by releasing Ca(2+) from multiple Ca(2+) stores in a manner independent of the production of inositol-1,4,5-trisphosphate, followed by Ca(2+) influx from external space.

Sporadic microsatellite instability is specific to neoplastic and preneoplastic endometrial tissues

Microsatellite instability is a frequent (13%-24%) finding in sporadic endometrial adenocarcinoma and its precursor lesions, but most studies are limited to patients who already have malignant or premalignant endometrial disease. We performed retrospective testing for microsatellite instability in women in whom cancers showing microsatellite instability developed later and prospective testing in randomly selected normal and anovular endometrial biopsy specimens. Microsatellite instability in cancer-bearing biopsy specimens accurately reflected that seen in matched malignant tissues obtained at hysterectomy. In 1 patient, microsatellite instability developed in a scanty sample of fragmented endometrial tissues 7 years before the onset of endometrial cancer. Prospective testing for microsatellite instability in the endometria of women unselected for subsequent appearance of endometrial cancer showed a very low rate of microsatellite instability. Only 1 endometrial specimen showing microsatellite instability was found among 75 anovulatory endometrial specimens, and none were found in 377 normal endometrial specimens and 46 polyps examined. Microsatellite instability may precede the onset of histologically diagnosed carcinoma but is rare in randomly sampled histologically normal endometrial tissues.

Allelic imbalance in lichen sclerosus, hyperplasia, and intraepithelial neoplasia of the vulva

BACKGROUND

Few studies have addressed in detail the genetic alterations that occur in vulvar squamous carcinomas (VSCC) and their precursor lesions. In a previous study, we determined the most common chromosomal loci for allelic imbalance (AI) in HPV-positive and -negative VSCCs. The present study was designed to determine whether AI and the microsatellite instability phenotype (MIN) were present in epithelial lesions known to be associated with VSCC.

DESIGN

Fifty-seven epithelial loci were analyzed, including HPV-positive (classic) and -negative (differentiated) vulvar intraepithelial neoplasms (VINs), lichen sclerosus (LS), and nonatypical hyperplasias. Thirty-one epithelial loci (55%) were obtained from patients with associated invasive vulvar carcinoma. HPV status was determined by polymerase chain reaction analysis. AI and MIN were determined by comparisons of microdissected target tissues with stromal controls, targeting 11 chromosomal loci.

RESULTS

AI was identified in all epithelial categories, involving at least one chromosomal locus in 67, 53, 50, and 43% of classic VIN, differentiated VIN, hyperplasia, and LS. MIN was infrequent (10-13%), but confined to HPV-negative epithelial changes. HPV-positive lesions generally scored for AI more frequently, but certain loci scored nearly equally in both HPV-positive and -negative lesions, including 8p, 11q, and 17p. There were no differences in frequency of AI between epithelia with and without associated invasive carcinoma.

CONCLUSIONS

The presence of allelic imbalance in vulvar hyperplasia and LS supports the hypothesis that these alterations are at greater risk for neoplasia despite the absence of conspicuous cellular atypia. A model is proposed in which these changes represent monoclonal expansion and are at empirically greater risk for subsequent "critical events" leading to morphologic atypia (VIN). The possibility that these early genetic changes influence both HPV-positive and -negative pathways merits further study.

Spontaneous variability of cardiac output in ventilated critically ill patients

OBJECTIVE

To define the magnitude of spontaneous cardiac output variability over time in sedated medical intensive care unit patients attached to a continuous cardiac output monitor, and to determine whether high level positive end-expiratory pressure or inverse inspiratory-to-expiratory (I:E) ratio ventilation resulted in greater variability over time than low positive end-expiratory pressure with conventional I:E ratio ventilation.

DESIGN

Prospective study.

SETTING

Medical intensive care unit in a tertiary medical center.

PATIENTS

A total of 22 hemodynamically stable acute respiratory failure patients with a pulmonary artery catheter inserted for hemodynamic monitoring

INTERVENTIONS

After being sedated, patients were randomized ultimately to receive pressure control ventilation first at setting A (high positive end-expiratory pressure [15 cm H2O] with conventional I:E ratio [1:2]) and then at setting B (low positive end-expiratory pressure [5 cm H2O] with inverse I:E ratio [2:1]), or vice versa, and then at setting C (low positive end-expiratory pressure [5 cm H2O] with conventional I:E ratio [1:2]). Each ventilation setting period lasted 1 hr.

MEASUREMENTS AND MAIN RESULTS

Cardiac output (CO) was measured continuously. The continuous CO value displayed was updated every 30-60 secs. The updated value reflected an average of the previous 3-6 mins. The coefficient of variation (CV) of CO for each setting in each patient was calculated to represent the spontaneous variability. The mean CO+/-SD and CV of each setting was 5.7+/-1.8 L/min and 4.4% for setting A, 5.6+/-1.5 L/min and 4.6% for setting B, and 5.9+/-1.7 L/min and 4.8% for setting C. Analysis of variance revealed no significant differences between the CVs of the three settings. The 95% confidence interval for the COs for each setting was approximately the mean CO+/-0.1 x mean CO measured.

CONCLUSIONS

In critically ill sedated medical intensive care unit patients with stable hemodynamics, the spontaneous variability of cardiac output over time was not significant. High positive end-expiratory pressure (15 cm H2O) and inverse ratio ventilation (2:1) did not contribute to increased spontaneous variability of cardiac output.

Increased absolute number but not proportion of gamma/delta T-lymphocytes in the bronchoalveolar lavage fluid of patients with active pulmonary tuberculosis

SETTING

The proportions and absolute cell count of gamma/delta T-lymphocytes in the peripheral blood of patients with pulmonary tuberculosis (PTB) remains controversial. Since PTB is an infections airway disease, bronchoalveolar T-lymphocytes should be a better indicator of local immune T-cell reaction after TB infection than peripheral blood T-lymphocytes.

OBJECTIVE

To quantitate the absolute cell count and proportions of gamma/delta T-lymphocytes in the bronchoalveolar lavage fluid (BALF) of patients with active PTB.

DESIGN

Bronchoalveolar lavage (BAL) and analysis of lymphocytes in the BALF was performed in 25 patients with active PTB and 16 normal controls. All of the patients were negative for HIV infection and none was immunocompromised. BALF and blood were prepared for cell differential count and flow cytometry analysis using monoclonal antibodies CD3, CD4, CD8, CD25, HLA-DR and gamma/delta as well as alpha/beta T-lymphocyte receptors.

RESULTS

The number of cells per volume of recovered BALF was significantly higher in the patients with active PTB than in normal controls. BALF from active PTB patients also showed increased percentage of lymphocytes and neutrophils. The absolute number of total lymphocytes, CD3+ lymphocytes and CD3+ gamma/delta T-lymphocytes were significantly higher in the BALF, but not in the blood, of patients with TB, however, the proportions of CD3+ gamma/delta T-lymphocytes in BALF of patients with TB was comparable to that of normal controls. gamma/delta T-lymphocytes in the BALF rarely expressed CD4, CD25, and HLA-DR in both groups.

CONCLUSION

These results suggest that gamma/delta T-lymphocytes are not the major subpopulation of CD3+ lymphocytes in the BALF that react to mycobacterial infection in the patients with clinically established active TB.

Mouse peroxiredoxin V is a thioredoxin peroxidase that inhibits p53-induced apoptosis

We have identified human and mouse peroxiredoxin V (Prx-V) by virtue of the sequence homologies to yeast peroxisomal antioxidant enzyme PMP20. Prx-V represents the fifth of the six currently known subfamilies of mammalian peroxiredoxins. It is a novel organellar enzyme that has orthologs in bacteria. Biochemically, Prx-V is a thioredoxin peroxidase. One important aspect of p53 function in mammalian cells involves induction of apoptosis likely mediated by redox. We show that overexpression of Prx-V prevented the p53-dependent generation of reactive oxygen species. Likewise, Prx-V inhibited p53-induced apoptosis. Thus, Prx-V is critically involved in intracellular redox signaling.

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.

Foot complications in people with diabetes: a community-based study in Taiwan

BACKGROUND AND PURPOSE

This comparative cross-sectional and community-based study was aimed at defining foot complications in diabetic patients. These data have not yet been reported for Asian societies.

METHODS

Of a population of 3,602 subjects aged 35 years or more in Chin-Shan, Taipei, 309 diabetic patients were identified. Two hundred and nineteen (71%) of those patients were compared to 100 individuals randomly selected for the nondiabetic control group in the same community.

RESULTS

Three diabetic patients underwent lower extremity amputation and four had skin ulcerations. Diabetic patients had a significantly higher prevalence of peripheral neuropathy (32.4% vs 16%), arterial insufficiency (12.6% vs 3.0%), and medial arterial calcification (13.6% vs 5.0%), when compared to the nondiabetic controls. The age and sex-adjusted rates of hallux valgus, loss of skin hair on the dorsum of the foot, tinea unguium, arterial insufficiency, medial artery calcification, and peripheral neuropathy were significantly higher in diabetic than nondiabetic subjects. Aging and hyperglycemia (> 140 mg/dL) increased the prevalence of foot complications in both groups. Foot complications were also remarkably associated with the duration of diabetes (p = 0.003).

CONCLUSIONS

This study shows that diabetes mellitus is associated with an increased likelihood of foot complications in this geographically defined Taiwanese population. Patient age and diabetic duration are associated with the significantly higher prevalence of foot complications.

Vertical alignment axis for transtibial prostheses: a simplified alignment method

BACKGROUND AND PURPOSE

To evaluate a simplified method of alignment for fitting a transtibial prosthesis known as the vertical alignment axis method.

METHODS

We measured the relationship between the vertical projection of the prosthetic socket center (geometric center of the cross section of the transtibial prosthetic socket at the level of the patella tendon bar) and the alignment reference center (junction of the middle and posterior thirds of the longitudinal axis of the shoe) in 36 dynamically aligned transtibial prostheses. The prostheses were fabricated by students, and the fit (proper vs improper) was assessed by the faculty.

RESULTS

The faculty members found 26 of the 36 prostheses to be properly fitted. The vertical projections of the socket centers of the properly-fitted prostheses were concentrated within a small area of the shoe tracing (a mean value of 1.3 mm medially and 6.4 mm anteriorly from the alignment reference center). Conversely, in the improperly-fitted prostheses, the vertical projections of the socket center were scattered well away from the alignment reference center; the mediolateral deviation was significantly greater for improperly-fitted prostheses than for those that were properly fitted (p < 0.001).

CONCLUSIONS

These results demonstrate the usefulness of the vertical alignment axis procedure. This procedure may help clinicians to better understand the alignment of transtibial prostheses and gait deviations associated with improper prosthesis fit.

Erratum: hirakura Y, lin M-C, kagan BL. 1999. Alzheimer amyloid Abeta1-42 channels: effects of solvent, pH, and congo red. J neurosci res 57:458-466

Erratum:Hirakura Y, Lin M-C, Kagan BL. 1999. Alzheimer amyloid Abeta1-42 channels: Effects of solvent, pH, and Congo Red. J Neurosci Res 57:458-466. In the article referenced above, incorrect figures were substituted for figures 1 and 4. The correct figures appear below. The publisher regrets this error.

Pulmonary mechanics in patients with prolonged mechanical ventilation requiring tracheostomy

This study was performed to assess the changes in pulmonary mechanics before and after tracheostomy in patients with prolonged mechanical ventilation and to detect pre-tracheostomy physiologic factors that predict the outcome of weaning from mechanical ventilation. Pulmonary mechanics were recorded before and after tracheostomy in 20 patients. Work of breathing, mean airway resistance and pressure/time product showed no significant differences after tracheostomy. Peak inspiratory pressure was significantly reduced (pre 33.4 +/- 11.8 vs post 28.6 +/- 9.2 mmHg). There was no difference in age or duration of mechanical ventilation between two different groups according to the outcome (weaned and not-weaned). Pre-tracheostomy intrinsic positive end expiratory pressure (PEEPi) was significantly lower in the weaned group (1.1 +/- 1.6 vs 2.7 +/- 1.4 mmHg). A significant difference was also found in pre-tracheostomy compliance (Cstatic) (47.3 +/- 36.9 vs 28.8 +/- 16.5 ml/cmH2O). We concluded that tracheostomy changed pulmonary mechanics very little except for a fall in peak inspiratory pressure. Patients who had better underlying lung mechanics (higher Cstatic and lower PEEPi) had better chances of weaning from mechanical ventilation after tracheostomy.

Measurement of post-lens tear thickness

PURPOSE

A method to measure the tear film beneath a soft contact lens, referred to as post-lens tear thickness (PLTT), would have many applications to contact lens research. In this study a noninvasive technique for measuring the PLTT is presented.

METHODS

The feasibility of measuring the tear layer by optical pachometry was first assessed using a model eye. The baseline corneal thickness (B) of both eyes of 21 subjects was measured, etafilcon-A ionic disposable soft contact lenses (58% water) were inserted, and the total thickness (T) of the cornea, contact lens, and PLTT were measured. After the pachometry readings the lenses were removed and their center thickness (C) determined. The PLTT was calculated using the equation: PLTT = T-(B+C). Two sets of measurements of T were performed at 15 and 25 minutes after lens insertion. The entire procedure was repeated at a second visit.

RESULTS

The pachometry measurements of the small aqueous reservoir between the model eye and the lens closely matched those obtained by direct microscopic measurement. For human PLTT, the mean values (and 95% confidence intervals) for right eyes on visits 1 and 2 were 11 (8, 13) and 12 (10, 15) microm, respectively, and for left eyes were 12 (10, 15) and 11 microm (8, 14) microm, respectively.

CONCLUSIONS

It is possible to measure the post-lens tear thickness using optical pachometry. The variability between repeated measurements suggests that with careful sample size planning, the technique is sufficiently precise to be useful in group assessments of PLTT.

Esophageal cancer mortality and total hardness levels in Taiwan's drinking water

The possible association between the risk of esophageal cancer and hardness levels in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. All eligible esophageal cancer deaths (2084 cases) of Taiwan residents from 1987 through 1996 were compared with deaths from other causes (2084 controls), and the hardness levels of the drinking water used by these residents were determined. Data on water hardness throughout Taiwan have been collected from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes and the controls were pair-matched to the cases by sex, year of birth, and year of death. The results show that there is a 42% excess risk of mortality from esophageal cancer in relation to the use of soft water (adjusted odds ratio and 95% confidence intervals was 1.42 (1.22-1.66). This is an important finding for the Taiwan water industry and human health.

Tracheal neurilemmoma mimicking bronchial asthma--a dilemma of difficult diagnosis: case report

Tracheal tumors are often overlooked as a cause of pulmonary symptoms until they reach an advanced state. They are often presented with a prolonged cough and shortness of breath. Most tracheal tumors in adults are cancerous (80% to 90%). Benign tracheal tumors are rare in adult patients. A case history is presented of a 19-year-old patient with a rare tracheal neurilemmoma. He was treated as having bronchial asthma initially, but his signs and symptoms did not improve with traditional therapy. The possibility of the presence of an upper airway obstruction was not raised until the typical "inspiratory tubular sound" was heard. Flow-volume loop testing, bronchoscopy, and three-dimensional computed tomography (3-D CT) confirmed the diagnosis of upper airway obstruction caused by a tracheal tumor. Therefore, surgical intervention rather than bronchoscopic removal was performed without difficulty. The patient was leading a stable life 8 months after a surgical resection. The presence of an upper airway obstruction can be proven by flow-volume loop testing and 3-D CT. Further pathologic confirmation can be accomplished by bronchoscopy. High suspicion of an upper airway obstruction such as a tracheal lesion should be raised when bronchial asthma patients fail to respond to conventional treatment.

Alzheimer amyloid abeta1-42 channels: effects of solvent, pH, and Congo Red

Substantial genetic and biochemical evidence implicates amyloid peptides (Abeta) in the etiology of Alzheimer's Disease (AD). Recent evidence indicates that Abeta1-42 is the predominant species in the hallmark senile amyloid plaque of AD. Furthermore, Abeta1-42 forms aggregates inside lysosomes of cultured neurons leading to lysosomal disruption and cell death. We report here that Abeta1-42 forms slightly cation selective, voltage-independent ion channels with multiple conductance levels at neurotoxic concentrations in planar bilayer membranes. The channels show substantial irregularity of activity, and the size of conductances and the length of open lifetimes depend on solvent history. Formation of channels requires anionic lipids, is enhanced in acidic solutions, and is inhibited by Congo Red. These properties suggest that the channels are formed by aggregates of Abeta1-42. In addition, the channels are reversibly blocked by zinc in a voltage-independent manner. The properties of these channels would likely render them neurotoxic to relevant neurons in vivo. These results are consistent with the channel hypothesis of Abeta neurotoxicity.

Comparison of indoor allergens, allergic scores, and demographic data in Taiwanese adults with asthma or allergic rhinitis, or both

We examined the relationships between exposure to different indoor allergens and demographic factors in 515 adult Taiwanese patients with allergic diseases such as asthma and rhinitis. Patients who had positive screening results on an immunoglobulin E (IgE) test were recruited from the outpatient clinics of Chang Gung Memorial Hospital. Patients were divided into the following three groups: asthma (n = 332), combined asthma and allergic rhinitis (n = 165), and allergic rhinitis (n = 18). Serum samples were analyzed for IgE by enzyme-linked immunosorbent assay. Significantly elevated titer of dust mite-specific IgE were found in all three groups, with markedly higher levels in the combined asthma and allergic rhinitis group (p < 0.05). Allergen scores were significantly related to the demographic variables of older age (> or = 65 years), female gender, and spring season, with significantly lower scores (p < 0.05). No significant difference in allergen scores was found among cigarette smoking subjects and subjects from residential areas. Multiple linear regression analysis revealed significant allergic contributors to be, in order of importance, age, gender, and atopic disease category. We conclude that mite allergen exposure is the most significant factor associated with asthma and/or allergic rhinitis in Taiwan. Younger subjects and males had a higher rate of asthma and/or allergic rhinitis.

Tuberculin purified protein derivative up-regulates the telomerase activity of peripheral blood mononuclear cells from patients with pulmonary tuberculosis

Telomerase activity was detectable in cells of tuberculous pleural effusions at high percentage. To investigate the possible role of telomerase in the immune function, we examined the proliferating state and the expression of telomerase activity in peripheral blood mononuclear cells (PBMC) from 13 patients with pulmonary tuberculosis (TB) and 13 healthy volunteers in response to tuberculin purified protein derivative (PPD) challenge. Exposure of cells to phytohemagglutinin (PHA) significantly promoted PBMC proliferation during a 6 day-period in both TB patient and healthy volunteer groups. PPD treatment also significantly promoted PBMC proliferation during a 6 day-period in TB patient group, but had no significant effect in healthy volunteer group. During the same period, telomerase activity was detected in every PHA- and PPD-treated samples of the TB patient group. However, the telomerase activity was not detected in PPD-treated samples from healthy donors and all the untreated samples. Our results indicate that the telomerase activity in PBMC could be induced by PPD stimulation in TB patients. Telomerase activity may thus play a permissive role in cell division and clonal expansion of the immune cells in response to TB.

Allelic loss in human papillomavirus-positive and -negative vulvar squamous cell carcinomas

Vulvar squamous cell carcinoma (VSCC) is a biologically and morphologically diverse disease, consisting of human papillomavirus (HPV)-positive and -negative tumors that differ in their morphological phenotypes and associated vulvar mucosal disorders. This study analyzed the frequencies of allelic loss (loss of heterozygosity (LOH)) in HPV-positive and -negative VSCCs to identify potential targets for the study of preinvasive diseases, to determine whether HPV status influenced patterns of LOH, and to determine whether these patterns differed from HPV-positive tumors of another genital site, cervical squamous cell carcinomas (CSCC). DNA extracted from microdissected archival sections of two index tumors, one each HPV negative and positive, was analyzed for LOH at 65 chromosomal loci. Loci scoring positive with either sample were included in an analysis of 14 additional cases that were also typed for HPV. Frequencies of LOH at loci were computed in a panel of HPV-positive and -negative VSCCs. Twenty-nine loci demonstrated LOH on the initial screen and were used to screen the remaining 14 tumors. High frequencies of LOH were identified, some of which were similar to a prior karyotypic study (3p, 5q, 8p, 10q, 15q, 18q, and 22q) and others of which had not previously been described in VSCC (1q, 2q, 8q, 10p, 11p, 11q, 17p, and 21q). With the exception of 5q and 10p, there were no significant associations between frequency of LOH and HPV status in VSCC. LOH at 3p and 11q were frequent in both VSCC and CSCC; however, allelic losses at several sites, including 5q, 8q, 17p, 21q, and 22q, were much more common in VSCC. VSCCs exhibit a broad range of allelic losses irrespective of HPV status, with high frequencies of LOH on certain chromosomal arms. This suggests that despite their differences in pathogenesis, both HPV-positive and -negative VSCCs share similarities in type and range of genetic losses during their evolution. Whether the different frequencies of LOH observed between VSCC and CSCC are real or reflect differences in stage and/or tumor size remains to be determined by further comparisons. The role of these altered genetic loci in the genesis of preinvasive vulvar mucosal lesions merits additional study.

Comparison of liver resection for hepatocellular carcinoma in hepatitis B and hepatitis C-related cirrhotic patients

BACKGROUND/AIMS

The differences of liver resection for hepatocellular carcinoma (HCC) between hepatitis B and C-related cirrhotic liver remain unknown. This study compares the surgical results of HCC in hepatitis B and hepatitis C-related cirrhotic patients in an area endemic of hepatitis B.

METHODOLOGY

A retrospective comparison of the clinicopathological features and early and long-term results of 110 cirrhotic patients with seropositive hepatitis B surface antigen only (group B) and 55 patients with seropositive anti-hepatitis C antibody only (group C) was carried out.

RESULTS

Group C patients were older, had a lower serum alpha-fetoprotein level, greater indocyanine retention rate, and higher incidence of multicentric tumors. Tumor size was larger and there was a higher incidence of combined satellite nodules in group B patients. There were no significant differences in operative morbidity and mortality between the two groups. Group B patients had a slightly shorter disease-free interval (p = 0.07) but a better actuarial survival rate (p = 0.05) than group C patients.

CONCLUSIONS

The hepatitis status did not affect the operative risks in cirrhotic livers. However, after resection of HCC, poorer liver functional reserve in hepatitis C-related cirrhotic patients caused poorer actuarial survival rate when compared with hepatitis B-related cirrhotic patients.

Concomitant splenectomy for hypersplenic thrombocytopenia in hepatic resection for hepatocellular carcinoma

BACKGROUND/AIMS

Resection of hepatocellular carcinoma (HCC) in patients with liver cirrhosis and hypersplenic thrombocytopenia (HSTC) is risky. Controversy exists concerning the role of concomitant splenectomy for HSTC in cirrhotic patients undergoing hepatectomy for HCC.

METHODOLOGY

During the past 10 years, 294 patients have undergone hepatic resection for HCC in our department. Among them, 11 cirrhotic patients with severe HSTC (platelet count < or = 80000/mm3) underwent splenectomy simultaneously. The clinical outcomes were retrospectively reviewed.

RESULTS

The resected spleen weighed 479 +/- 242 g. The post-operative mortality and morbidity were 9.1% and 27.3%, respectively. In all patients, the platelet count was elevated to above 100000/mm3, and serum total bilirubin was significantly lowered within 1 week of operation. The overall 5-year actuarial and disease-free survival rates were 66.7%. None of the patients developed severe infectious complications during the follow-up period.

CONCLUSIONS

Concomitant splenectomy for severe HSTC in cirrhotic patients undergoing hepatectomy for HCC is justified as the benefits of concomitant splenectomy by far surpass the adverse effects.