Analysis of progressive change in automated visual fields in glaucoma

PURPOSE

To detect and estimate the rate of progression of visual field loss in subjects with glaucoma who undergo long-term automated perimetric visual field testing.

METHODS

Automated visual field data were obtained for subjects with glaucomatous visual field loss and a minimum of seven threshold field tests over at least 4.5 years. Univariate linear regression was performed with respect to mean deviation (MD), corrected pattern standard deviation (CPSD), mean thresholds of clusters corresponding to the Glaucoma Hemifield Test (GHT), and thresholds of 52 individual test locations. Subjects were classified as progressive or stable (unchanged or improved) based on the slope and statistical significance of these parameters. Adjusted P values were used to maintain the overall type 1 error at 5%.

RESULTS

One hundred ninety-one subjects with a mean follow-up period of 7.1 years (range, 4.5 to 10.5 years) and a mean number of visual field tests of 9.5 (range, 7 to 16) were included. Twenty-four subjects (12.6%) showed progression in MD (mean slope [95% confidence interval], -1.26 [-1.50, -1.01] dB/year), and 27 (14.1%) showed progression in CPSD (mean slope [95% confidence interval], 0.71 [0.58, 0.84] dB/year). Thirty-five subjects (18.3%) had > or = 1 progressive GHT cluster. The mean slope in progressive clusters ranged from -1.51 [-1.82, -1.20] to -2.84 [-3.39, -2.29] dB/year. Thirty-six subjects (18.8%) had > or = 1 progressive individual test locations. Fifty-two subjects (27.2%) were classified as progressive based on progression of CPSD, > or = 1 cluster and/or > or = 1 point.

CONCLUSIONS

Fewer than 1 in 3 subjects progressed by any one of the criteria for progression over an average of 7.1 years. Rates of progression that could be statistically confirmed were in the range of approximately 1 to 5 dB/year, depending on the number of fields, the variability over time, and the parameter assessed (global indices, GHT clusters, or individual points). No correlation between initial visual field status and the rate of progression was found. A minimum of approximately 5 years of follow-up with annual perimetry would be required to detect significant changes in the visual field by linear regression.

State of dermatology training: the residents' perspective

Changes in health care delivery necessitate modification in dermatology training. While the residents at The University of Alabama at Birmingham were planning their 1995-1996 curriculum, several questions regarding the most appropriate allocation of time and resources arose. Interest in other residency curricula prompted the development of a national survey of dermatology residents. Our purpose was to provide comprehensive data regarding the didactic, clinical, surgical, and other aspects of today's U.S. dermatology residency training from the perspective of the residents. It is hoped these data will assist dermatology residency programs with evaluation of their current curricula. A comprehensive 31-question multiplechoice survey was mailed to 631 residents in 70 U.S. dermatology residency programs. Results were tabulated and median values and percentages of responses were obtained. A Wilcoxon rank-sum test, a chi-square analysis, and logistic regression analysis were performed on survey items on the basis of residents' satisfaction with the training program. Two hundred forty-eight responses (39%) were returned with all years of training well represented. Median values and percentages obtained outlined the didactic, clinical, surgical, and other aspects of dermatology residency training. Seventeen percent of residents believed they were not being adequately trained. Satisfaction with training was noted with more didactic faculty involvement, consultations and research, and surgical procedures performed per month. Residents with enriched didactic, clinical, and surgical training experiences are more satisfied with their training programs.

Urinary nitric oxide synthase activity and cyclic GMP levels are decreased with interstitial cystitis and increased with urinary tract infections

PURPOSE

Since urinary nitric oxide synthase (NOS) activity correlates with certain disease process affecting the urinary tract and since nitric oxide increases cyclic GMP levels by activating guanylyl cyclase, urinary particulate NOS activity and cyclic GMP levels are evaluated in female patients with interstitial cystitis (IC) and compared with those from female controls and female patients with urinary tract infections (UTIs).

MATERIALS AND METHODS

Urinary NOS activity is measured as the formation of [(14)C]-L-citrulline from [(14)C]-L-arginine, and urinary cyclic GMP levels are measured by an [(125)I]-radioimmunoassay.

RESULTS

Female patients with IC have significantly less NOS activity in their urine pellet particulate fractions than female control females UTIs, 2.3 +/- 1.0, 14 +/- 3.0, and 120 +/- 10 pmol. citrulline formed/min./mg. protein. Urinary cyclic GMP levels are significantly lower in IC patients than in female controls or females with UTIs: 0.50 +/- 0.06, 0.82 +/- 0.14. and 3.72 +/- 0.81 micromol. cyclic GMP/g. creatinine.

CONCLUSIONS

Regulation of urinary NOS activity with subsequent changes in nitric oxide and cyclic GMP may be an important determinant of symptoms and immunologic responses to UTIs and IC.

Deletion or lack of expression of CDKN2 (CDK4I/MTS1/INK4A) and MTS2 (INK4B) in acute lymphoblastic leukemia cell lines reflects the phenotype of the uncultured primary leukemia cells

The CDKN2 gene has been recently localized to a chromosomal region found to be deleted in leukemias and solid tumors. CDKN2 encodes a 16 kDa protein product (p16INK4A), which functions as a specific inhibitor or the cyclin-dependent kinases 4 and 6. There have been many reports indicating a higher frequency of deletions of the CDKN2 gene in a variety of tumor cell lines, in comparison to primary tumors. These studies raise the possibility that deletions of CDKN2 may be a rare event in primary tumors, and in fact arise in vitro, during the establishment of permanent cell lines. To address this issue, we determined whether the CDKN2 gene deletions found in acute lymphoblastic leukemia (ALL) cell lines are also detected in the primary leukemia samples. Eleven cell lines were identified which had available frozen primary samples of their original leukemic tissue. Five out of 11 of these cell lines, as well as their primary samples had homozygous CDKN2 deletions. The remaining six cell lines and their primary samples retained at least one copy of the CDKN2 gene. Of the six CDKN2+ cell lines, five expressed CDKN2 mRNA, but only one of these expressed the p16 protein product (as did its primary sample). Our results indicate that CDKN2 deletions present in the studied ALL cell lines arose in the primary leukemic cells, and not during cell line establishment or prolonged in vitro culture.

Is computed tomography a useful adjunct to the clinical examination for the diagnosis of pediatric gastrointestinal perforation from blunt abdominal trauma in children?

Perforations of the gastrointestinal (GI) tract, compared to solid organ injuries, are a relatively infrequent sequela of blunt abdominal trauma in children. The purpose of this study is to review retrospectively the diagnostic modalities used in 30 children with proven traumatic intestinal perforations treated at one institution. Since computed tomography with intravenous and oral GI contrast is commonly used in the diagnosis of suspected solid organ injury from blunt abdominal trauma, we evaluated retrospectively the computed tomographic (CT) scan findings in these children in an attempt to accurately predict or suggest GI perforation. Between January 1987 and December 1993, 5,795 children were admitted. Three hundred fifty suffered blunt abdominal trauma of which 30 patients (8.5%) required surgery for a GI perforation and formed the basis for this study. Data collected were mechanisms of injury, results of admission and serial clinical examinations, results of radiologic imaging, associated injuries, operative findings, and outcome. Follow-up was obtained on all patients and averaged 2.5 years. Blows to the abdomen (handlebars, cars, kicks) were the most common cause of perforation, followed by seatbelt injuries. Eleven patients underwent immediate laparotomy an average of 0.75 hours after admission. The indication for surgery was shock (three), clinically apparent peritonitis (five), and free air on plain abdominal radiograph (three). Nineteen patients underwent "later" laparotomy, an average of 3.4 hours after admission, all because of the eventual development of peritonitis. Retrospective review of these CT scans revealed free air anterior to the liver in three, and the remaining 16 had CT findings suggestive of GI injury such as free fluid, focal fluid-filled thick-walled bowel loops, and mesenteric infiltration. There were five (26%) false negative CT scans performed an average of 5.0 hours after injury. We believe serial physical examinations are the gold standard for diagnosing pediatric GI perforation from blunt abdominal trauma. The CT scan may be a useful adjunct to the diagnosis of an intestinal perforation in patients who have no immediate indication for surgery. Presently, the only CT finding that is an absolute indication for laparotomy is free air (in the absence of pulmonary/mediastinal injury or barotrauma). The other CT "findings" need to be validated prospectively.

Perioperative perspective of a United Nations humanitarian mission

The use of deployable medical systems is not new to the US Army, but their use in support of United Nations peacekeepers is new. This article describes one Army unit's experience near Zagreb, Croatia, in 1993. The physical location, language and cultural barriers, and difficulty obtaining supplies posed significant challenges to those involved. The focus is on the OR team: its capabilities, achievements, and importance during this mission.

Bulimic weight-loss behaviors in military versus civilian weight-management programs

This descriptive study evaluated the presence of bulimic weight-loss behaviors in individuals enrolled in: (1) a military weight-management program (N = 51); (2) a civilian weight-management program (N = 53); and (3) a comparison (military normal-weight) group (N = 51). A modified version of the Stanford Eating Disorders Questionnaire was administered to all subjects. The results indicated that the military weight-management program group reported that they engaged in bulimic weight-loss behaviors two to five times more often than the comparison group, and that they engaged in vomiting, strenuous exercise, or use of sauna/steam room four times as often as the civilian weight-management program group. The results suggest that bulimic weight-loss behaviors may develop in individuals who feel extreme pressure to lose weight.

An autosomal recessive nonsyndromic form of sensorineural hearing loss maps to 3p-DFNB6

Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common form of congenitally acquired inherited hearing impairment. Although numerous loci are believed to exist, only five have been identified. Using a pooled genomic DNA screening strategy, we have identified a sixth locus, DFNB6, on 3p in the interval bounded by D3S1619 and D3S1766.

Consanguineous nuclear families used to identify a new locus for recessive non-syndromic hearing loss on 14q

Hearing impairment is inherited most frequently as an autosomal recessive isolated clinical finding (non-syndromic hearing loss, NSHL). Extreme heterogeneity and phenotypic variability in the audiometric profile preclude pooling of affected families and severely hamper gene mapping by conventional linkage analysis. However, in instances of consanguinity, homozygosity mapping can be used to identify disease loci in small nuclear families. This report demonstrates the power of this technique by identifying a locus for recessive NSHL on 14q (DFNB4).

Homozygous deletions of the CDKN2 (MTS1/p16ink4) gene in cell lines established from children with acute lymphoblastic leukemia

Homozygous deletions of the CDKN2 (MTS1/p16ink4) gene have been found at high frequency in cell lines derived from a variety of adult solid tumors. In order to investigate the status of the CDKN2 gene in cell lines established from childhood acute lymphoblastic leukemia (ALL), we surveyed 25 lines representing the major pediatric ALL phenotypes for the presence of this gene by Southern blot analysis. Homozygous deletions of all or part of the CDKN2 gene were detected in 21 (84%) cell lines, including 11 of 14 (79%) early-pre-B-ALL, four of five (80%) pre-B-ALL, and six of six T-ALL lines. CDN2 mRNA was detected by Northern blotting in each of the four lines containing an intact CDKN2 gene. These data suggest an important role for CDKN2 deletion in the cause and/or progression of pediatric ALL.

Quantitative trait locus for reading disability: correction

In the news article "Can risky mergers save hospital-based research?" by Wade Roush (19 May, p. 968), the statement that University Hospitals of Cleveland rose from 20th in the rankings of teaching hospitals funded by the National Institutes of Health (NIH) in 1991 to 12th at present was incorrect. In fact, it was Case Western Reserve University (CWRU), with which University Hospitals of Cleveland is affiliated, that received $69 million in NIH grants in 1993, making it the 20th largest recipient of such grants among medical centers; the university then received $97 million in 1994, raising its rank to 12th. About $15 million of the increase, or 53%, was attributable to CWRU's 1992 affiliation with Henry Ford Hospital in Detroit. Other hospitals affiliated with Case Western include MetroHealth Medical Center, Mount Sinai Medical Center, St. Luke's Medical Center, and Cleveland Veterans' Affairs Medical Center.

Linking the professional literature to nursing practice: challenges and opportunities

Occupational health nurses face the challenge of rapidly changing, increasingly complex work environments. To respond, they must have access to information and know how to manage it effectively to improve their clinical performance and achieve better client outcomes. Information technology has already had an impact on nursing. Many nurses routinely use computers to access laboratory reports, client records, and administrative programs. However few nurses make use of opportunities provided by information technology to access professional literature as a tool for applying new research to their practice.

Postoperative selective bowel decontamination prevents gram-negative bacterial translocation in small-bowel graft recipients

Gram-negative septic episodes are a potential risk of small-bowel transplantation; bacterial translocation through the graft is considered the mechanism. As a measure to prevent this complication, we evaluated postoperative selective bowel decontamination (SBD) in the rat model of orthotopic small-bowel transplantation [Lewis (LEW) and Brown-Norway (BN) rats as donors and recipients]. For 4 days after transplantation we gave FK 506, 2 mg/kg, which prevents rejection and results in indefinite recipient survival. For SBD, 24 mg/kg/day polymyxin E and 20 mg/kg/day tobramycin were administered via orogastric gavage to allograft recipients, both with and without FK 506 therapy. On Day 9, all rats were sacrificed, the peritoneal cavity was swabbed, and mesenteric lymph nodes (MLN), spleen, liver, and ileum were harvested for microbial qualitative and quantitative analysis. Animals with positive peritoneal swab cultures were excluded. SBD resulted in a significant reduction of the quantitative gram-negative bacterial flora in the ileum and cecum and of bacterial translocation to the MLN [0% versus 50% (no FK 506 therapy) and 8% versus 50% (FK 506 treated)]. In the allograft groups not treated with FK 506, SBD failed to significantly prolong survival, suggesting that acute rejection is not hastened by infection (bacterial translocation). We conclude that SBD in small-bowel-graft recipients prevents bacterial translocation by reducing intestinal gram-negative bacterial flora; this may reduce local and systemic infections by gut-derived organisms.

Overexpression of the MDM2 gene by childhood acute lymphoblastic leukemia cells expressing the wild-type p53 gene

The wild-type (wt) p53 tumor suppressor gene is commonly inactivated in human malignancies, either by mutations or by loss of expression. An additional proposed mechanism for inactivation of wt-p53 is amplification of the murine double minute 2 (MDM2) gene and overexpression of the MDM2 protein, which binds to p53 and eliminates its tumor suppressor function. To investigate a potential role for MDM2 in the inactivation of wt-p53 in pediatric acute lymphoblastic leukemia (ALL), we examined the expression of MDM2 and p53, as well as the occurrence of p53 mutations and possible amplification of the MDM2 gene, in 19 pediatric ALL cell lines and one pediatric acute myelogenous leukemia (AML) line. Although we did not find significant amplification of the MDM2 gene in any of the leukemic lines, we detected overexpression of MDM2 in all 10 lines that expressed wt-p53. Of the 10 lines without overexpression of the MDM2 gene, six (including the AML line) did not express p53, and four expressed mutant p53 with single point mutations in exons 7 and 8. To determine whether primary leukemic cells showed a similar correlation, we analyzed the original cryopreserved leukemic bone marrow cells from seven patients from whom cell lines were established. We obtained similar results from both the primary leukemic cells and the corresponding cell lines: overexpression of MDM2 was present in primary cells that expressed wt-p53 but not in cells that lacked expression of wt-p53. These findings suggest an important role for MDM2 in the pathogenesis of pediatric ALL in which leukemic cells express wt-p53.

The protective role of enteral IgA supplementation in neonatal gut origin sepsis

Preterm infants and infants unable to breast feed are particularly susceptible to gut origin sepsis. Many studies have shown the benefits of breast milk in decreasing the incidence of bacterial infections in neonates. Little in vivo work has focused on prevention of neonatal gut origin sepsis with breast milk components. The aim of this study was to determine whether supplementation of a standard neonatal formula with exogenous, luminally administered, human secretory IgA protects against gut origin sepsis in a newborn rabbit model. Sixty New Zealand white rabbit pups were delivered by cesarean section 1 day preterm and divided into two groups--the IgA group (n = 26) and the non-IgA group (n = 34). Animals were gavage-fed a standard artificial formula (KMR) twice daily. The IgA group was supplemented on days 3 and 4 with 6.25 mg/kg of human secretory IgA. The non-IgA group received an equal volume of saline. On the evening of day 3, the animals were orally challenged with Escherichia coli K100. The quantity of bacteria that colonized the cecum was similar in the two groups. The quantity of bacteria that translocated to the mesenteric lymph node, liver, and spleen was significantly lower in the IgA group (P < .05). The incidence of translocation to the organs was also significantly lower in the IgA group (P < .05). The exogenous secretory IgA showed specificity to E coli K100 by ELISA. These data show that neonatal formula supplemented with human secretory IgA decreases the incidence and quantity of bacterial translocation of E coli K100 in a neonatal rabbit model.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein quality of enteral nutrition products is consistent with label claims during shelf life and beyond expiration date

OBJECTIVE

Eternal formulas were monitored during their shelf life and beyond expiration date to examine protein quality.

DESIGN

Protein quality was determined by protein efficiency ratio (PER) bioassays and amino acid analyses.

SETTING

A certified laboratory performed the PER tests according to procedures established by the Association of Official Analytical Chemists and recognized by the US Food and Drug Administration (FDA). The amino acid analyses were performed in our laboratory using validated methods.

SAMPLES

Commercially available formulas (Ensure, Osmolite HN, TwoCal HN) that contained protein blends of caseinates or caseinates with soybean protein isolate were studied.

MAIN OUTCOME MEASURES

Achievement of protein-quality values greater than or equal to 70% of the fresh reference casein value as determined by the PER method would be consistent with adequate protein quality as described by the FDA. Levels of indispensable amino acids that meet or exceed the standards established by the National Research Council of the National Academy of Sciences are considered high-quality proteins. Levels of amino acids throughout shelf life were compared with published label claims.

RESULTS

Amino acid analyses, which included measurement of tryptophan and total sulfur amino acids, revealed that both fresh and outdated products met or exceeded standards for proteins of high biologic value and were consistent with label claims. The PER values ranged from 90% to 96% of the control diet for fresh product and 82% to 87% for products evaluated after expiration.

CONCLUSION

The enteral products studied provide high-quality protein throughout the shelf life of the product.

Overview of genetic auditory syndromes

Accurate determination of the cause of hearing loss is critically important for clinicians for prognosis and management. Recognition of genetic syndromes is especially important, but this is dependent upon clear delineation of the characteristics of the syndromes. Research into underlying mechanisms of hearing loss is also much more effective if the cause of the hearing loss is known to be the same in the subjects being studied. Family studies of hearing loss can be very important in determining the phenotypic range of the condition, but it has become clear that phenotypically similar families may not actually have the same genetic cause. Molecular genetic studies are needed to determine which genes, and even which mutations within genes, are responsible for specific syndromes. This paper reviews the methodology of gene localization (linkage) studies and describes a variety of genetic conditions, syndromic and nonsyndromic, which illustrate the varying relationships between genes, phenotypes, and mechanisms of hearing loss. Knowledge of the cause of hearing loss will facilitate understanding of the auditory system and development of optimum therapy.

Effect of secretory IgA on transepithelial passage of bacteria across the intact ileum in vitro

BACKGROUND

Bacterial translocation is a process believed to result in nosocomial infections. Secretory IgA (sIgA) may have a role in the prevention of translocation by its ability to bind and aggregate bacteria, a function termed "immune exclusion." The present study was done to determine the effect of specific binding of sIgA to bacteria on the movement of these organisms across the intact epithelial membrane.

STUDY DESIGN

Bacterial translocation across intact intestinal segments of rats were assessed in vitro using the Ussing model. Secretory IgA (0.25 mg per mL) from pooled human colostrum was added to the perfused segments of ileum in the Ussing system. Subsequently, the membranes were exposed to 5 x 10(9) cfu per mL Escherichia coli on their mucosal side. A second experiment tested the effect of human IgG when perfused with E. coli using the same preparation. All experiments had paired matched rats in a control group without immunoglobulin. The ability of sIgA and IgG to bind to E. coli was studied by an in vitro assay, as well as by transmission electron microscopy and immunofluorescence of random IgA/E. coli experiments. Measurements obtained in all experimental and control groups were the incidence and amount of bacterial passage and the potential difference generated by the intestinal segments (an index of viability).

RESULTS

There were no differences in potential difference between control and experimental groups in either of the two experiments. Secretory IgA bound E. coli and completely prevented passage of E. coli as compared with rats in the control group. IgG bound E. coli; however, the incidence of passage was equal to that of rats in the control group. However, the presence of IgG resulted in a significantly reduced number of bacteria that passed when compared with controls (p < 0.05). Electron microscopic studies revealed intact surface morphology and immunofluorescence revealed aggregates of IgA and E. coli on the mucosal, but not submucosal, surface of the ileal membranes.

CONCLUSIONS

This study provides direct evidence of immune exclusion by sIgA. When bound to bacteria, it prevents passage across a morphologically intact segment of viable intestinal tissue.

The role of the mucus gel layer in intestinal bacterial translocation

The mucus gel layer is thought to be a vital component of the intestinal mucosal barrier. The purpose of this study is to determine if decreasing mucus production following ischemia and reoxygenation of the intestinal mucosa would alter bacterial translocation in an in vitro rat mucosal model. Clonidine was used to decrease mucus production associated with an ischemia/reoxygenation insult. Bacterial translocation was studied in a modified Ussing chamber using Escherichia coli K100. The quantity of mucus produced, as well as the incidence and quantity of bacteria translocating was measured. In the clonidine-treated animals, there was a significant decrease in the amount of mucus produced compared to the control animals. The clonidine animals also had a higher quantity of bacteria translocating during the reoxygenation period compared to the control animals. The mucus gel layer is protective against in vitro translocation of bacteria following an ischemia/reoxygenation insult.

Ion resonance electromagnetic field stimulation of fracture healing in rabbits with a fibular ostectomy

Rabbits with a fibular ostectomy were exposed for 28 days to magnetic fields that satisfied the ion resonance conditions for calcium or magnesium. The rabbits were exposed to whole body treatment for 1/2 hour, 3 hours, or 24 hours per day. The fibulae from the experimental and control animals were removed surgically and were subjected to force-deflection testing to establish the stiffness of the healed fracture. The fibulae from the rabbits exposed to the ion resonance magnetic fields were found to be 55-299% (p < 0.01) more robust than the fibulae from the control animals.

Quantitative trait locus for reading disability on chromosome 6

Interval mapping of data from two independent samples of sib pairs, at least one member of whom was reading disabled, revealed evidence for a quantitative trait locus (QTL) on chromosome 6. Results obtained from analyses of reading performance from 114 sib pairs genotyped for DNA markers localized the QTL to 6p21.3. Analyses of corresponding data from an independent sample of 50 dizygotic twin pairs provided evidence for linkage to the same region. In combination, the replicate samples yielded a chi 2 value of 16.73 (P = 0.0002). Examination of twin and kindred siblings with more extreme deficits in reading performance yielded even stronger evidence for a QTL (chi 2 = 27.35, P < 0.00001). The position of the QTL was narrowly defined with a 100:1 confidence interval to a 2-centimorgan region within the human leukocyte antigen complex.

Establishment of a leukemia cell line with i(12p) from a patient with a mediastinal germ cell tumor and acute lymphoblastic leukemia

We report the establishment of a leukemia cell line (UoC-B10) from a patient who developed leukemia several months after the diagnosis of a mediastinal yolk sac tumor. The patient's yolk sac tumor responded to combination chemotherapy, and a mature teratoma with focal areas of hematopoiesis was subsequently resected. However, 5 months after the initial diagnosis, the patient developed an acute lymphoblastic leukemia with a precursor B-cell phenotype. Cytogenetic analysis showed an i(12p) abnormality in the patient's leukemia cells and in the UoC-B10 cell line. The i(12p) was also identified retrospectively in the mediastinal tumor cells by fluorescent in situ hybridization analysis. The UoC-B10 cell line, which has been growing continuously for > 24 months in culture, was Epstein-Barr virus negative and was generally concordant with the patient's leukemia cells by analysis of immunophenotype, karyotype, and genotype. The UoC-B10 cell line possesses receptors for granulocyte-colony-stimulating factor, a cytokine which the patient received as part of his treatment protocol. This cell line may be useful in studying the relationship between i(12p) and hematological differentiation of human mediastinal germ cell tumors.