Neonatal outcome after prolonged preterm rupture of the membranes

Pulmonary hypoplasia was diagnosed in 14 of 88 infants (16%) delivered in 1983 to 1986 after rupture of the membranes of greater than or equal to 7 days with onset before 29 weeks' gestation. Logistic regression analysis applied to examine the relative importance of perinatal risk factors in the prediction of pulmonary hypoplasia showed that gestational age at onset of rupture of the membranes had a significant effect (p = 0.002) on the odds that pulmonary hypoplasia developed in the neonate, whereas the duration of rupture of the membranes (p = 0.11) and the degree of oligohydramnios (p = 0.65) did not. Postnatally, the presence of pulmonary hypoplasia was associated with the severity of skeletal compression deformities (p less than 0.0001). The development of skeletal compression deformities was associated with severe oligohydramnios (p = 0.05) and duration of rupture of the membranes (p = 0.02) but not gestational age at rupture of the membranes (p = 0.77). Gestational age at onset of rupture of the membranes being the best single predictor of pulmonary hypoplasia suggests that the stage of lung development at rupture of the membranes may be important.

Otogenic lateral sinus thrombosis in children

INTRODUCTION

The clinical picture of lateral sinus thrombosis (LST) has changed with the advent of antibiotics, as have the utility of various diagnostic tests. LST may appear in children as a complication of acute otitis media, but nowadays it is more frequently encountered in adults with long-standing chronic ear disease.

METHOD

A retrospective study of all the pediatric patients with LST between 1982 and 1997.

RESULTS

Thirteen cases of LST were diagnosed and treated by our department. In six cases, LST was due to acute otitis media and in the remaining cases it was due to chronic otitis media. Headache, fever, aural discharge and mastoid tenderness were the most frequent findings in these patients and four patients were initially diagnosed with meningitis. In the majority of the patients, LST was accompanied with other intracranial complications, such as perisinus abscess, brain abscess and meningitis. One patient with multiple brain abscesses, unresponsive to several drainage procedures, died. The other patients recovered and have since been followed-up as out-patients.

CONCLUSION

LST may be difficult to diagnose due to previous antibiotic treatment and to the overlap of clinical findings with other entities such as meningitis. Despite the value of modern imaging techniques in the investigation of the disease, a high index of suspicion based on the clinical picture is warranted. Our results are consistent with those of other recent studies, who found that mortality of LST has dropped below 10%.

Nonopsonic phagocytosis of strains of Pseudomonas aeruginosa from cystic fibrosis patients

Pseudomonas aeruginosa is the predominant respiratory pathogen in patients with cystic fibrosis, but its mechanism of persisting in pulmonary secretions is poorly understood. We observed that three nonmucoid cystic fibrosis P. aeruginosa strains were phagocytized and one strain resisted phagocytosis by human polymorphonuclear leukocytes in the absence of serum. Phagocytosis was assessed by luminol-enhanced chemiluminescence, inspection of stained smears, bactericidal assay, reduction of nitroblue tetrazolium dye, and electron microscopy. Phagocytosis, determined by visual inspection, occurred at 35 degrees C but not at 4 degrees C. Nonopsonic phagocytosis was inhibited most efficiently by D-mannose, mannose-containing saccharides, and D-fructose. Opsonin-dependent phagocytosis of P. aeruginosa and of zymosan was not markedly inhibited by mannose, suggesting different leukocyte receptors for nonopsonic and opsonic phagocytosis.

Prognostic factors in diffuse proliferative lupus glomerulonephritis

A number of clinical laboratory and biopsy-derived parameters were assessed for their prognostic significance in the short (24 months), intermediate (60 months) and long terms in 45 patients (43 female, 2 male) with diffuse proliferative lupus glomerulonephritis (DPGN). The factors evaluated were serum creatinine (SCr) and urinary protein at time of biopsy, initial dose of prednisone and immunosuppressive after biopsy, activity index (AI), chronicity index (CI), their individual components, extent of extraglomerular (tubulo-interstitial) immune deposits (EGD) and mean number of intraglomerular monocytes per glomerulus (NSE index). Using proportional hazards analysis to evaluate the parameters, SCr (P = 0.003), AI (P = 0.005) and NSE index (P = 0.038) were shown to be significant predictors of outcome when all variables except the components of AI and CI were considered. When AI and CI were omitted but their components included, SCr (P = 0.0005), NSE index (P = 0.024), extent of karyorrhexis (P = 0.035) and glomerulosclerosis (P = 0.033) were then demonstrated to be significant prognostic factors of DPGN. The results suggest that intraglomerular monocyte infiltration has a protective effect and confirm that AI index is a relatively powerful predictor of outcome. Histologic and nonhistologic biopsy factors contribute significant additional prognostic information to that provided by SCr.

Prophylaxis of urinary tract infection in persons with recent spinal cord injury: a prospective, randomized, double-blind, placebo-controlled study of trimethoprim-sulfamethoxazole

PURPOSE

To determine the efficacy of trimethoprim-sulfamethoxazole (TMP-SMX) for prophylaxis of urinary tract infection in persons with recent spinal cord injury, during the first 4 months of intermittent catheterization.

PATIENTS AND METHODS

One hundred twenty-nine adults (112 men, 17 women) with recent acute spinal cord injury participated in a randomized, double-blind, placebo-controlled trial, and were studied for up to 16 weeks. Low-dose TMP-SMX (TMP 40 mg, SMX 200 mg) or placebo was given once daily. Clinical observations, urine cultures, and cultures of rectal and urethral swabs were made weekly. Subjects who developed breakthrough bacteriuria received conventional antimicrobial therapy and prophylaxis was continued.

RESULTS

Sixty-six TMP-SMX recipients (57 men, 9 women) and 60 placebo recipients (52 men, 8 women) are evaluable for efficacy. Among male subjects, bacteriuria was present during 50% or more of study weeks in 30% of TMP-SMX recipients and in 56% of placebo recipients (p = 0.003). The interval to the onset of bacteriuria was prolonged in TMP-SMX recipients (p < 0.0001). TMP-SMX recipients without bacteriuria in any given week had a lower probability of having bacteriuria the subsequent week (0.26) than did placebo recipients (0.49) (p < 0.0001). At least 1 episode of definite symptomatic bacteriuria (bacteriuria and fever and at least 1 classical manifestation of urinary infection) occurred in 4 of 57 TMP-SMX-treated men and in 18 of 52 placebo-treated men (p < 0.0003). We observed similar trends in women, but differences did not reach statistical significance, perhaps because the number of females was small. Adverse events suspected to be due to medications were frequent in this population of patients with recent severe injuries and led to discontinuation of the study in 10% of the TMP-SMX group and 8% of the placebo group. Adverse events included neutropenia (TMP-SMX: two; placebo: three), pseudomembranous colitis (TMP-SMX: one), severe skin rash (TMP-SMX: two; placebo: one), and drug fever (TMP-SMX: one). The proportion of all episodes of bacteriuria that were due to TMP-SMX-resistant organisms was unexpectedly high in the placebo group (51%), and increased progressively according to year of enrollment in the study. By Year 3, all subjects in the placebo group had at least one episode of TMP-SMX-resistant bacteriuria. Gram-negative enteric bacilli resistant to TMP-SMX were recovered from rectal swabs (TMP-SMX 49%, placebo 42%) and urethral swabs (TMP-SMX 33%, placebo 26%) in similar proportions of subjects in the two study groups.

CONCLUSIONS

Prophylaxis with TMP-SMX significantly reduces bacteriuria and symptomatic urinary tract infection in persons with recent acute spinal cord injury during bladder retraining using intermittent catheterization. However, adverse reactions attributable to TMP-SMX are common in this population. Colonization and breakthrough bacteriuria with TMP-SMX-resistant organisms are frequent and may seriously limit the usefulness of this strategy, particularly in an institutional setting.

Age-related changes in humoral and cell-mediated immunity in Down syndrome children living at home

Abnormalities of humoral and cell-mediated immunity have been described in Down syndrome but reported findings have been inconsistent. Confounding factors have included age, institutional versus home life, hepatitis B antigenemia, and zinc deficiency. To clarify this problem, we studied 64 children with Down syndrome (DS) compared with an age-matched control group. All children had always lived at home. All the DS children were negative for hepatitis B surface antigen. Serum zinc concentration in the DS group was on average 12 micrograms/dl lower than age-matched control children. They also had significantly lower levels of immunoglobulin M, total lymphocyte count, T and B lymphocytes, and T helper and suppressor cells. In vitro lymphocyte response to phytohemagglutinin and concanavalin A was significantly reduced at all ages in the DS group. Lymphocyte response to pokeweed mitogen increased with age in control children but decreased in the DS children. By 18 yr, the mean response for DS was 60000 cpm lower than controls. The DS group had significantly higher concentrations of immunoglobulins A and G than controls and the difference increased with age. Complement fractions C3 and C4 were also higher in the DS group at all ages. The number of HNK-1 positive cells was higher in the DS group than controls at all ages. When hepatitis and institutionalization are excluded as confounding factors, DS children still differ in both humoral and cell-mediated immunity from an age-matched control group.

Increased compliance in response to salbutamol in premature infants with developing bronchopulmonary dysplasia

We compared the effect of salbutamol and placebo in a double-blind study of preterm infants with bronchopulmonary dysplasia, using a randomized, crossover design with several replicates per subject. Sixty-two tests were performed on 20 ventilator-dependent infants weighing less than 1500 gm. Patients were entered as early as the first week of life and studied for at least 4 weeks or until extubation. Each subject was his own control subject and was randomly assigned to a placebo-salbutamol or salbutamol-placebo sequence administered on 2 consecutive days of each week. Static compliance, expiratory resistance of the respiratory system, and changes in transcutaneous oxygen and carbon dioxide tension were measured. Static compliance improved by 0.240 ml/cm H2O/kg (35.3%) after salbutamol and by 0.010 ml/cm H2O/kg (2.8%) after placebo (p less than 0.0001). The presence of a predetermined decrease in carbon dioxide tension correlated with large changes in static compliance per kilogram and with the need for a high level of fractional inspired oxygen. The magnitude of the clinical and physiologic improvement observed, and the early response suggest that long-term bronchodilator therapy starting as early as the second week of life may be beneficial for very low birth weight infants with early bronchopulmonary dysplasia.

Genetics of natural resistance to herpes simplex virus type 1 latent infection of the peripheral nervous system in mice

The genetics of natural resistance to the development of latent infection in the trigeminal ganglia of mice inoculated in the lip with herpes simplex virus type 1 (HSV-1) was examined. Based on coefficients of a logistic regression relating latency to strain and HSV-1 concentration, inbred strains of mice formed a continuum of resistance ranging from most resistant (C57BL/6J) to most susceptible (PL/J). When these results were analysed along with latency data derived from studies employing a non-fatal concentration of HSV-1, three subpopulations were identified among these strains: resistant (C57BL/10J, BALB/cByJ, C57BL/6J), moderately resistant (DBA/2J, SWR/J, A/J, AKR/J, DBA/1J) and susceptible (PL/J, LP/J, CBA/J). Results from F1 hybrids between resistant and moderately resistant strains (B6D2F1/J, B6AF1/J) and between resistant and susceptible strains [(C57BL/6J X CBA/J)F1, (C57BL/6J X LP/J)F1)] indicated that resistance is dominant. Data from both inbred and congenic strains failed to show an association between H-2 and resistance to the development of a latent infection. Studies of mortality also indicated that a continuum was present, with C57BL/10J, C57BL/6J and DBA/1J being most resistant and PL/J mice most susceptible. When inbred strains were categorized on the basis of resistance to the development of latent infection and mortality, five groups could be identified. Group A are strains resistant to both mortality and latency (C57BL/6J, C57BL/10J, DBA/1J) while group B consists of one strain (BALB/cByJ) intermediate in resistance to mortality but resistant to latency. Group C are strains intermediate in resistance to mortality and susceptible to latency (LP/J, CBA/J) while Group D are strains susceptible to mortality and intermediate in susceptibility to latency (AKR/J, SWR/J, DBA/2J). Group E consists of one strain (PL/J) susceptible to both mortality and latency. These results indicate that host factors play an important role in the establishment of latent infection in vivo.

Bias Optimality in Controlled Queueing Systems

This paper studies an admission control M/M/1 queueing system. It shows that the only gain (average) optimal stationary policies with gain and bias which satisfy the optimality equation are of control limit type, that there are at most two and, if there are two, they occur consecutively. Conditions are provided which ensure the existence of two gain optimal control limit policies and are illustrated with an example. The main result is that bias optimality distinguishes these two gain optimal policies and that the larger of the two control limits is the unique bias optimal stationary policy. Consequently it is also Blackwell optimal. This result is established by appealing to the third optimality equation of the Markov decision process and some observations concerning the structure of solutions of the second optimality equation.

Perturbation theory for Markov reward processes with applications to queueing systems

We study the effect of perturbations in the data of a discrete-time Markov reward process on the finite-horizon total expected reward, the infinite-horizon expected discounted and average reward and the total expected reward up to a first-passage time. Bounds for the absolute errors of these reward functions are obtained. The results are illustrated for a finite as well as infinite queueing systems (M/M/1/S and ). Extensions to Markov decision processes and other settings are discussed.

Evaluation of seven immunoassays for detection of rotavirus in pediatric stool samples

The performance of seven commercially manufactured rotavirus assays was evaluated with 144 pediatric stool specimens and compared with electron microscopy (EM) findings. The four enzyme-linked immunosorbent assays used were Rotazyme II, Pathfinder, IDL rotavirus immunoassay, and Enzygnost (Behring) rotavirus assay. The three latex tests were Meritec rotavirus detection test, Virogen Rotatest, and Bartels rotavirus latex test. Test outcomes were compared with EM on the basis of sensitivity, specificity, positive-negative predictive value, and the kappa statistic. Relative to EM, Meritec had the highest specificity (97%), followed by Virogen (95%), IDL (91%), Pathfinder (85%), Behring (81%), Bartels (72%), and Rotazyme (71%). The sensitivities were as follows: Rotazyme (92%), Pathfinder (89%), Bartels (86%), Virogen (86%), Behring (82%), Meritec (71%), and IDL (75%). Patient age and sex did not influence test results. Owing to the absence of a true standard, the tests were also compared with each other on the basis of the kappa statistic, the frequency of positive test results, and the frequency of samples in which a test differed from all other tests. Using these measures, the assays could be classified into three groups with progressively decreasing utility: group 1 (Virogen, Meritec, IDL, and EM), group 2 (Pathfinder and Behring), and group 3 (Rotazyme and Bartels). Laboratory criteria were also compared. Latex tests were faster and required less equipment than enzyme-linked immunosorbent assays. The Virogen latex assay showed the best overall performance, which made it our choice for rapid and accurate rotavirus diagnosis. However, in children who have gastrointestinal symptoms with negative rotavirus test results, EM will be useful until such time as immunological tests for other enteric viruses are available.

Transient immune deficiency in patients with acute Epstein-Barr virus infection

To study the effect of primary Epstein-Barr virus (EBV) infection on antigen-specific antibody production, we immunized 17 college students who had developed acute infectious mononucleosis with the T-cell dependent neoantigen bacteriophage phi X174. During the early phase of infectious mononucleosis, the proportion of peripheral blood lymphocytes displaying Ia and T8 (CD8) phenotypes was increased and the T helper/suppressor (T4/T8) ratio was decreased (less than 1). These abnormalities disappeared during the convalescent phase. Correlating with EBV-induced changes in T lymphocytes, we demonstrated depressed humoral immune responses to bacteriophage phi X174 both in vivo and in vitro. In vitro coculture experiments indicated that the Ia+ suppressor T cells could inhibit antibody production and isotype switch. Removal of T8+ lymphocytes from patient T cells normalized in vitro antibody synthesis. In addition, impaired B-cell function was shown to be in part responsible for deficient antibody production. These studies demonstrate that infection with EBV affects both B and T lymphocytes and causes a broad-based transient immune deficiency in patients with uncomplicated infectious mononucleosis.

Immunity to soluble retinal antigen in patients with uveitis accompanying juvenile rheumatoid arthritis

Studies of immunity to bovine soluble retinal antigen (antigen S) were carried out using serum and peripheral blood lymphocytes from children with juvenile rheumatoid arthritis and chronic anterior uveitis (JRA-uveitis), children with JRA alone, children with nonrheumatic diseases, and controls who had no ocular or rheumatic disease. Enzyme-linked immunosorbent assay and the lymphocyte transformation assay were used to determine immunity. Antibody to antigen S was present significantly more frequently in children with JRA-uveitis than in children with JRA alone, children with nonrheumatic disorders, or controls. These latter groups did not differ in positivity for this antibody. Lymphocyte transformation occurred more frequently in children with JRA-uveitis than in children with JRA alone or controls. Children with JRA alone and controls had similar frequencies of lymphocyte transformation positivity. Enzyme-linked immunosorbent assay positivity and lymphocyte transformation positivity tended to occur in different children. Children with JRA-uveitis who had HLA-B35 had the highest frequency of antibody to antigen S. Immunity to antigen S may be the result of ocular damage by mechanisms other than a pathogenic mechanism per se.

Operations research methods improve chemotherapy patient appointment scheduling

BACKGROUND

Clinical complexity, scheduling restrictions, and outdated manual booking processes resulted in frequent clerical rework, long waitlists for treatment, and late appointment notification for patients at a chemotherapy clinic in a large cancer center in British Columbia, Canada. A 17-month study was conducted to address booking, scheduling and workload issues and to develop, implement, and evaluate solutions.

METHODS

A review of scheduling practices included process observation and mapping, analysis of historical appointment data, creation of a new performance metric (final appointment notification lead time), and a baseline patient satisfaction survey. Process improvement involved discrete event simulation to evaluate alternative booking practice scenarios, development of an optimization-based scheduling tool to improve scheduling efficiency, and change management for implementation of process changes. Results were evaluated through analysis of appointment data, a follow-up patient survey, and staff surveys.

RESULTS

Process review revealed a two-stage scheduling process. Long waitlists and late notification resulted from an inflexible first-stage process. The second-stage process was time consuming and tedious. After a revised, more flexible first-stage process and an automated second-stage process were implemented, the median percentage of appointments exceeding the final appointment notification lead time target of one week was reduced by 57% and median waitlist size decreased by 83%. Patient surveys confirmed increased satisfaction while staff feedback reported reduced stress levels.

CONCLUSION

Significant operational improvements can be achieved through process redesign combined with operations research methods.

Infection and immunity in Down syndrome: a trial of long-term low oral doses of zinc

To determine whether orally administered zinc supplements could correct the abnormal humoral and cell-mediated immunity of Down syndrome, we randomly assigned 64 children with Down syndrome, aged 1 to 19 years and living at home, to receive either zinc gluconate or placebo daily for 6-month periods with crossover from one regimen to another. Control subjects were siblings and age-matched, unrelated children. Serum zinc, copper, and measures of immune system competence were tested at 3- or 6-month intervals. Parents kept daily logs of clinical symptoms such as cough and diarrhea and of physician visits. Mean serum zinc concentrations increased to about 150% of baseline during zinc supplementation, but we found no effect on serum levels of copper, immunoglobulins, or complement; on lymphocyte number or subset distribution; or on in vitro response to mitogens. Children with Down syndrome who were receiving zinc had a trend toward fewer days or episodes of cough and fever but no change in other clinical variables. Long-term, low-dose oral zinc supplementation to improve depressed immune response or to decrease infections in children with Down syndrome cannot be recommended.

Granular cell lesions in head and neck: a clinicopathological study

Twenty-five cases of granular cell lesions in the region of the head and neck are presented. The adult form (18 cases) was more frequent in women, and the most frequent sites were the tongue, the skin, and subcutaneous tissues, followed by the lip and buccal mucosa. One lesion occurred in the larynx. The congenital forms (7 cases) all occurred in female infants and involved the mucosa overlying either the anterior ridge of the maxilla or the mandible. Immunohistochemical studies revealed positive staining for S100 protein in all the granular cell tumors of the adult but in none of the congenital granular cell epulides. Embryonic antigen was present in the cells of all the congenital cases and in three-quarters of the adult cases. The significance of the histological and immunohistochemical findings is discussed. We conclude that the congenital and adult lesions are similar morphologically but are not necessarily of similar histogenesis. The findings with respect to S100 protein favor a neural (Schwann cell) origin of the adult granular cell tumor, but not the congenital form.

Reliability audit of a regional cardiac surgery registry

OBJECTIVE

The British Columbia Provincial Cardiac Registry collects demographic and clinical data on all patients who undergo cardiac surgery procedures in the province. The purpose of this study was to compare the reliability of data contained in Registry with data contained in hospital charts.

METHODS

Registry and hospital charts were compared for 480 cases. Thirty cases were randomly selected for the province's 16 cardiac surgeons. For each case, 10 distinct fields were selected for analysis and classified as consistent, inconsistent, or rejected (data unavailable in one or other source).

RESULTS

The overall rate of consistency between charts and the Registry was 86.4%, with an inconsistency rate of 9.9% and a rejection rate of 3.7%. Consistency rates varied significantly across the 10 fields and among the 16 surgeons. Pairwise comparisons of rates between fields indicated that specific field types were problematic and should be targeted for improvement. In addition, pairwise comparisons of rates between surgeons indicated that further education on Registry use is required.

CONCLUSIONS

Recommendations for database design and management include provision of standard definitions for all fields; education of users; extension of the number of mandatory fields; revision of check-off box fields to yes/no/unsure fields; and collection of data close to the time that it is generated.