Long-term outcome of percutaneous intervention for pulmonary vein stenosis after pulmonary vein isolation procedure

OBJECTIVES

Report long-term outcomes of percutaneous intervention in patients with pulmonary vein stenosis (PVS) after pulmonary vein isolation (PVI) from a single center over 16 years.

BACKGROUND

Outcome reports of percutaneous intervention for PVS resulting from PVI are limited.

METHODS

Retrospective review of all patients with PVS after PVI who underwent percutaneous intervention at the Cleveland Clinic Foundation between January 2000 and December 2016.

RESULTS

A total of 205 patients underwent cardiac catheterization for PVS during the study period. Completely occluded veins which could not be recanalized occurred in six patients. Of the remaining 199 patients, 27 (14%) were lost to follow-up, leaving 172 patients with 276 veins for analysis. Balloon angioplasty was performed in 62 veins and stent implantation in 250 (primary in 214, to treat postdilation restenosis in 36). Re-intervention occurred in 45/62 (73%) balloon-dilated veins and 45/250 (18%) stented veins. Freedom from re-intervention at 1 and 5 years was 90 and 73% following stenting versus 40 and 23% following balloon dilation (p < .001, Hazard ratio (HR) = 5.7). Veins with stent diameter ≥7 mm (n = 231) had greater freedom from re-intervention (95% at 1 year, 79% at 5 years) than veins with stents <7 mm (43% at 1 year, 9% at 5 years), p < .001. There was clear symptomatic improvement after intervention and no procedural mortality.

CONCLUSIONS

Stent implantation at ≥7 mm for PVS after PVI is associated with low rates of re-intervention, in contrast to balloon dilation and stenting with small conventional stents.

Low Indeterminate Rates Associated With Use of the QuantiFERON-TB Gold In-Tube Test in Children With Inflammatory Bowel Disease on Long-term Infliximab

BACKGROUND

Tumor necrosis factor alpha (TNF-α) inhibitors are linked with increased risk of reactivation of active tuberculosis. The QuantiFERON-TB Gold In-Tube test is approved for screening latent tuberculosis infection in children and adults. There are limited data on the test performance in children on long-term treatment with TNF-α inhibitors. The objective of this study was to assess the proportion of indeterminate results for the QuantiFERON-TB Gold In-Tube in children with inflammatory bowel disease (IBD) on long-term infliximab treatment and to evaluate the range of interferon-γ responses to mitogen.

METHODS

A single-center prospective study of children 5 to 19 years of age with IBD on long-term infliximab treatment (>3 months). Each child was assessed for tuberculosis exposure risk and had blood drawn for the QuantiFERON-TB Gold In-Tube. Data on the range of interferon-γ responses and final QuantiFERON-TB Gold In-Tube test results were collected.

RESULTS

Ninety-three children were included, with a median age of 16 years. The median total duration of infliximab therapy was 34 months (range, 3-119 months). The QuantiFERON-TB Gold In-Tube was indeterminate in 1 patient (1.1%), positive in 2 patients, and negative in 90 patients. The maximum interferon-γ response to mitogen (10 IU/mL) was observed in 82 patients (88%), with only 1 patient having an inadequate response. The proportion of indeterminate results was significantly lower than the prospectively hypothesized rate of 8%, based on prior studies in nonimmunosuppressed patients (P = 0.004).

CONCLUSIONS

Pediatric patients with IBD on long-term treatment with infliximab had an adequate interferon-γ response to mitogen and a low indeterminate rate when assessed with the QuantiFERON-TB Gold In-Tube test. This study demonstrates a robust interferon gamma response to phytohemagglutinin stimulation in a pediatric population on long-term therapy with infliximab. The QuantiFERON-TB Gold In-Tube test may therefore be useful as a periodic screening tactic for latent TB in children on long-term infliximab therapy.

The acceptability of human papillomavirus vaccine among parents and guardians of newborn to 10-year-old children

STUDY OBJECTIVE

The purpose of our study was to evaluate HPV vaccine acceptance among parents and guardians of children aged 0-10 years.

DESIGN

Prospective questionnaire study.

SETTING

Cleveland Clinic Children's Hospital.

PARTICIPANTS

Parents and guardians of children aged 0-10 years.

INTERVENTIONS

Brief HPV vaccine educational intervention.

OUTCOME MEASURE

Desire for child to get HPV vaccine.

RESULTS

We enrolled 81 participants in the study; 70 (86%) were female, and 39 (49%) were Caucasian. Prior to receiving an educational fact sheet about HPV and the HPV vaccine, only 49% of participants reported that they wanted their young child to receive the HPV vaccine when it becomes available. After receiving the fact sheet, this number increased to 70%, suggesting that a simple educational intervention could significantly affect vaccine acceptance in this population (P = .001). Other significant results of this study included that HPV vaccination would receive greater acceptance if the participants believed that it can prevent HPV infection in their child (P = .0024), it was perceived to be safe (P = .0005), and if the vaccine were recommended by a physician (P < .0001). Participants' attitudes about HPV vaccination were not affected by concerns over whether receiving the vaccine might mean the child is more likely to have sex or to have multiple sexual partners.

CONCLUSIONS

Our results suggest that if it were approved for children aged 0-10 years, the HPV vaccine would be accepted by the parents and guardians provided they received adequate educational information about it.

A clinical picture of Guillain-Barré syndrome in children in the United States

The authors describe the demographics, clinical presentation, investigation, treatment, and outcomes of pediatric patients with Guillain-Barré syndrome. They identified 35 pediatric patients with Guillain-Barré syndrome presenting to a tertiary academic center over a 20-year period. The most common presenting symptoms were paresthesias (54%), weakness (49%), and myalgias (49%). Sensation was affected in 54% of patients, and hyporeflexia or areflexia was present in 94% of patients. Cranial nerve dysfunction (46%) and autonomic involvement (eg, changes in blood pressure, pulse, bowel/bladder control, or priapism; 46%) were also common. Autonomic dysfunction, cranial nerve involvement, and albuminocytological dissociation were significantly associated with a decreased time to nadir, the point when symptoms peaked (P = .015, .007, and .005, respectively). Although not statistically significant, treatment with plasmapheresis had a better success rate than intravenous immunoglobulin. The authors' results will help to further delineate the clinical picture of Guillain-Barré syndrome in children and refine treatment strategies.

Mortality outcomes in pediatric rheumatology in the US

OBJECTIVE

To describe mortality rates, causes of death, and potential mortality risk factors in pediatric rheumatic diseases in the US.

METHODS

We used the Indianapolis Pediatric Rheumatology Disease Registry, which includes 49,023 patients from 62 centers who were newly diagnosed between 1992 and 2001. Identifiers were matched with the Social Security Death Index censored for March 2005. Deaths were confirmed by death certificates, referring physicians, and medical records. Causes of death were derived by chart review or from the death certificate. Standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs) were determined.

RESULTS

After excluding patients with malignancy, 110 deaths among 48,885 patients (0.23%) were confirmed. Patients had been followed up for a mean +/- SD of 7.9 +/- 2.7 years. The SMR of the entire cohort was significantly decreased (0.65 [95% CI 0.53-0.78]), with differences in patients followed up for > or =9 years. The SMR was significantly greater for systemic lupus erythematosus (3.06 [95% CI 1.78-4.90]) and dermatomyositis (2.64 [95% CI 0.86-6.17]) but not for systemic juvenile rheumatoid arthritis (1.8 [95% CI 0.66-3.92]). The SMR was significantly decreased in pain syndromes (0.41 [95% CI 0.21-0.72]). Causes of death were related to the rheumatic diagnosis (including complications) in 39 patients (35%), treatment complications in 11 (10%), non-natural causes in 25 (23%), background disease in 23 (21%), and were unknown in 12 patients (11%). Rheumatic diagnoses, age at diagnosis, sex, and early use of systemic steroids and methotrexate were significantly associated with the risk of death.

CONCLUSION

Our findings indicate that the overall mortality rate for pediatric rheumatic diseases was not increased. Even for the diseases and conditions associated with increased mortality, mortality rates were significantly lower than those reported in previous studies.

Total pulmonary vein occlusion complicating pulmonary vein isolation: diagnosis and treatment

BACKGROUND

Pulmonary vein stenosis (PVS) complicating pulmonary vein isolation (PVI) can progress to total pulmonary vein occlusion (PVO). Little is known about the accuracy of noninvasive diagnosis and treatment of PVO.

OBJECTIVE

The purpose of this study was to study the diagnostic accuracy of noninvasive testing and the feasibility and outcome of percutaneous intervention for PVO.

METHODS

Computed tomography (CT)-diagnosed and angiographically confirmed PVOs were identified from percutaneous interventions for PVS complicating PVI between December 2000 and December 2008. Diagnostic accuracy of CT combined with lung perfusion scan was studied. Outcome of percutaneous intervention was reviewed.

RESULTS

CT diagnosed "PVO" in 53 PVs, with only 20 of 53 determined angiographically to be totally occluded. True PVO had lower perfusion (4.0%) compared with CT-diagnosed "PVO" (7.3%, P = .024). Recanalization was attempted in 9 and successful in 8. Of the 8 patients, 7 were dilated with 4.5- to 7-mm balloons and 1 was stented primarily (7 mm). At repeat catheterization 2.9 +/- 0.8 months later, 6 of 7 pulmonary veins (PVs) were stented to 5 to 10 mm. At follow-up of 11.3 +/- 8.7 months, all but 1 PV remained patent (mean diameter 6.9 +/- 1.7 mm). Flow to the lung quadrant increased from 5.6% before recanalization to 12.2% at last follow-up (P = .016). Symptoms improved in all but one patient.

CONCLUSION

PVO is overestimated by CT. Quantification of lung perfusion improves diagnostic accuracy, but angiography remains the gold standard. Recanalization of PVO can be attempted when a remnant of the PV is visible. Good mid-term patency rates and improved perfusion were observed with a two-stage approach of initial dilation and subsequent stenting. Longer follow-up and larger numbers of patients are needed to better understand when to intervene for PVO.

Differential growth of human embryos in vitro: role of reactive oxygen species

OBJECTIVE

To examine the relationship of early human embryonic development with the level of reactive oxygen species (ROS) in the culture media on the first day (day 1 ROS) after insemination.

DESIGN

A prospective study.

SETTING

Patients undergoing assisted reproduction in a teaching hospital.

PATIENT(S)

Patients undergoing conventional IVF (n = 104; 115 cycles) and intracytoplasmic sperm injection (ICSI) (n = 91; 96 cycles) were included. Both fertilization and early cultures were performed in human tubal fluid with 5% serum substitute supplement.

INTERVENTION(S)

Day 1 ROS levels in the central well (sample) and the outer well (control) of each embryo culture dish were measured after overnight incubation by chemiluminescence assay using luminol as the probe.

MAIN OUTCOME MEASURE(S)

Fertilization rate and embryo quality at day 3 and 5 were recorded for each cycle. Age, parity, and demographic features were also compared.

RESULT(S)

High day 1 ROS levels in culture media were associated with low blastocyst rate, low fertilization rate, low cleavage rate, and high embryonic fragmentation with ICSI but not with conventional IVF. High day 1 ROS levels in culture media were associated with lower pregnancy rates in both IVF and ICSI cycles.

CONCLUSION(S)

Reactive oxygen species generated in culture media by day 1 may be an important biochemical marker for early embryonic growth. Increased embryonic fragmentation and slow cleavage rate may be partially attributed to early exposure of embryos to high ROS levels in ICSI cycles. Differential growth of ICSI embryos incubated under identical conditions may be in part due to differences in ROS levels of the culture medium surrounding these embryos.

Mechanical failure of the American Medical Systems Ultrex inflatable penile prosthesis: before and after 1993 structural modification

PURPOSE

The 700 Ultrex (American Medical Systems, Minnetonka, Minnesota) is the only penile prosthesis capable of length and girth expansion. Early experience with the 700 Ultrex showed an increased mechanical failure rate compared with the 700CX, mostly secondary to cylinder failure. In 1993 the Ultrex cylinders were modified. We examined the performance of the Ultrex device before and after modification.

MATERIALS AND METHODS

We compared our results with the Ultrex prosthesis before (group 1) and after (group 2) the 1993 modification. We implanted 239 devices from October 1989 to December 1999. A total of 26 patients have died. Followup was obtained on the results of 137 of the remaining 213 implants (64%), including 85 pre-modification devices in 85 patients and 52 post-modification devices in 51, via a mailed questionnaire, telephone survey or chart review. The questionnaire and survey included a 5-point satisfaction scale. Groups 1 and 2 were compared in regard to 3 end points, namely cylinder, mechanical and overall failure.

RESULTS

Followup was less than 1 to 136 months (median 92, 25th to 75th percentiles 43 to 108) in group 1 and less than 1 to 92 months (median 46, 25th to 75th percentiles 21 to 75) in group 2. The 5-year Kaplan-Meier estimates of overall, mechanical and cylinder survival in groups 1 and 2 were 64.7%, 70.7% and 80.2%, and 77.7% (p = 0.23), 93.7% (p = 0.017) and 96.2% (p = 0.008), respectively. Overall satisfaction was similarly high in groups 1 and 2 (mean 3.9 and 4 points).

CONCLUSIONS

On long-term followup the 1993 modification of the Ultrex cylinders appears to have significantly decreased the propensity of cylinder failure of the pre-modification device.

Obesity and gestational diabetes among African-American women and Latinas in Detroit: implications for disparities in women's health

OBJECTIVE

to estimate the prevalence of gestational diabetes mellitus (GDM), obesity, and excessive weight gain during pregnancy among Latinas and African-American women in a large Detroit health system and explore risk factors associated with GDM and its implications.

METHODS

Descriptive statistics, chi2 tests, analysis of variance, and logistic regression analyses were used to describe the prevalence of obesity, excessive pregnancy weight gain, and GDM and to assess factors associated with GDM risk in a cohort of 552 African-American women and 653 Latinas in a large Detroit health system.

RESULTS

Women ranged in age from 14 to 47 years. Almost 47% of African-American women and 37% of Latinas were overweight or obese, and 53% of African-American women and 38% of Latinas gained excessive weight during pregnancy. The prevalence of GDM was 5.4% among Latinas and 3.9% among African-American women. After adjusting for other risk factors, Latinas were 2.5 times more likely than African Americans to develop GDM. Other independent risk factors were family history of diabetes, age, body mass index, and gestational weight gain before 28 weeks.

CONCLUSION

Because most women have repeated contact with the health care system during and immediately after pregnancy, care providers have unique opportunities to identify and assist those who are at risk of obesity and diabetes.

Effect of Fluosol DA 20% on antibody response to type 3 pneumococcal polysaccharide in rats

Exchange transfusion with the oxygen-carrying resuscitation fluid, Fluosol DA 20% (FDA), interferes with the efficacy of penicillin therapy of pneumococcal infection in rats. Because this effect could not be attributed to an interaction between FDA and penicillin, the effect of FDA on the ability of rats to mount an antibody response to type 3 pneumococcal polysaccharide was tested. FDA (25 ml) was administered by isovolumetric exchange transfusion. Rats were immunized intravenously with 0.2 microgram of type 3 pneumococcal polysaccharide 3 days before, 1 day before, 1 day after, or 3 days after transfusion with FDA. IgM and IgG antibody responses were determined by ELISA 0, 3, 7, 10, 14, 21, and 28 days after immunization. When rats were immunized 3 days before or 1 day before transfusion with FDA, antibody levels were increased above control levels and remained relatively high through Day 28. When the animals were immunized 1 day after transfusion, antibody levels were approximately the same as in the control group. When the rats were immunized 3 days after transfusion, antibody levels were suppressed. These data suggest that FDA does not inhibit the humoral immune response when administered after or within 1 day before immunization, but does inhibit the response when immunization is given 3 days after transfusion.

Spurious elevation of automated leukocyte counts induced by Fluosol DA 20%

During studies with Fluosol DA 20% (FDA) in rats, an artifactual leukocytosis was observed when an impedance type electronic cell counter was used. The effect was found to be directly related to the duration of the interval between addition of an erythrocyte lysing fluid and counting, observed up to 11 d after transfusion with FDA, blood cell associated, reproducible in vitro, FDA concentration dependent, temperature dependent, and present when human blood was used instead of rat blood. Microscopically, the effect appears to be the result of agglutination of lysed erythrocyte membranes due to the interaction of erythrocytes, the emulsion component of FDA, and the quaternary ammonium salt component of the lysing fluid. These data suggest that FDA causes subtle changes in erythrocytes and raises the possibility that other cells may be similarly affected.

Effect of exchange transfusion with Fluosol DA 20% on splenic distribution and immunocompetence of rat lymphocytes

T- and B-splenic lymphocyte frequency, immune response 4 days after immunization with sheep red blood cells (SRBC), and proliferative response to concanavalin A (Con A) were determined 1, 3, and 5 days after exchange transfusion with Fluosol DA 20% (FDA) in adult, male Sprague-Dawley rats vs sham transfused rats. T-cell, T-helper, T-suppressor, and B-lymphocyte were reduced 1 day after transfusion (P less than or equal to 0.001). T- and B-lymphocyte frequencies were still reduced at day 3 (P = 0.0372). By day 5, there were no significant reductions in T-cell, T-helper, T-suppressor, and B-cell frequencies in the FDA-transfused rats. The frequency of cells with cytoplasmic IgG was reduced (P less than or equal to 0.025) in cells harvested from spleens of FDA-transfused rats and tested fresh. Proliferative response of splenic lymphocytes to Con A was unaffected by transfusion with FDA (P greater than or equal to 0.078). Splenic hemolytic plaques in response to SRBC were unaffected if rats were transfused 3 days after immunization with SRBC and 1 day prior to study (P = 0.941), enhanced if rats were transfused 1 day after SRBC immunization and 3 days prior to study (P = 0.0015), and suppressed if rats were transfused 1 day before SRBC immunization and 5 days before study (P less than 0.0001). Transfusion with FDA causes transient decreases in identifiable T and B lymphocytes, depresses cytoplasmic IgG-positive B cells, does not affect proliferative response to Con A, does not affect an ongoing specific immune response, enhances an early specific immune response, and inhibits the induction of a specific immune response.

Ototoxicity of intraventricularly administered gentamicin in adult rabbits

To determine whether daily intraventricular injection of gentamicin sulfate is ototoxic, adult male rabbits were given 0.2 ml of saline (group 1; n = 8) or 0.25 mg/kg of gentamicin sulfate in 0.2 ml of saline (group 2; n = 7) by intraventricular infusion once a day for 21 d. All rabbits were also given intramuscular gentamicin sulfate, 2 mg/kg, twice daily. Before and after antibiotic treatment, brainstem auditory evoked responses (BAERs) were recorded. During the experimental period, neurologic examinations were performed on all rabbits. After treatment, the animals were euthanized; brain tissue and cochleas were then removed for histopathologic examination. The ratios of neurologic abnormalities observed in group 1 and 2 animals, respectively, were 0/8 and 5/7; of abnormal BAERs, 0/8 and 5/7; of abnormal brain morphology, 2/5 and 6/6; and of abnormal cochlear morphology, 0/6 and 7/7. The electrophysiologic evidence of auditory deficit and the structural evidence of ototoxic insult are significantly associated (p less than or equal to 0.006) with intraventricularly administered gentamicin sulfate. These data suggest that intraventricular gentamicin should be used with caution.

Effect of exchange transfusion with an oxygen-carrying resuscitation fluid on the efficacy of penicillin therapy of pneumococcal infection in rats

The effects of exchange transfusion with Fluosol DA (FDA) or stroma-free hemoglobin on the outcome of pneumococcal infection in rats were determined. Rats were sham transfused or exchange transfused with 25 ml of FDA or stroma-free hemoglobin. They were then challenged intraperitoneally with Streptococcus pneumoniae type 3 and treated with penicillin for 120 h. Only 2 of 15 (13.3%) FDA-transfused rats were alive at 312 h compared with 11 of 15 (73.3%) concurrently studied sham-transfused control rats (P = 0.0016). Of 10 stroma-free hemoglobin-transfused rats and 10 concurrently studied sham-transfused control rats (P = 0.98), 8 from each group (80%) were alive at 312 h. Penicillin therapy only suppressed pneumococcal infection in FDA-transfused rats, and relapse occurred after therapy was stopped. This effect could not be attributed to interference with the bactericidal activity of penicillin against pneumococci, to an alteration in the pneumococcal burden before penicillin therapy or to an alteration of the leukocyte and polymorphonuclear leukocyte response by FDA. In contrast, pneumococcal infection in stroma-free hemoglobin-transfused rats was cured with penicillin therapy. These data showed that FDA altered the ability of rats to respond to pneumococcal infection.

Effect of oxygen-carrying resuscitation fluids on the pharmacokinetics of antipyrine, diazepam, penicillin, and sulfamethazine in rats

The effects of exchange transfusion with an oxygen-carrying resuscitation fluid, Fluosol DA 20% or stroma-free hemoglobin, on the pharmacokinetics of antipyrine, diazepam, penicillin, and sulfamethazine were studied in rats. After transfusion with Fluosol DA 20% or stroma-free hemoglobin the pharmacokinetics of antipyrine, diazepam, and penicillin were unchanged when compared to control animals. After transfusion with Fluosol DA 20%, the t 1/2 of sulfamethazine was increased from 3.15 +/- 0.56 to 7.65 +/- 2.41 hr (p less than 0.05) and the Vd was increased from 60.7 +/- 17.5 to 152 +/- 16 ml (p less than 0.05). In contrast, after transfusion with stroma-free hemoglobin, the AUC of sulfamethazine was decreased from 129 +/- 28 to 80.5 +/- 27.7 micrograms X h X ml-1 (p less than 0.05) and there was an increase in Cl from 12.2 +/- 3.4 to 20.2 +/- 6.0 ml X h-1 (p less than 0.05) and Vd from 60.1 +/- 11.8 to 132 +/- 49 ml (p less than 0.05). The reason for these alterations is not clear. Fluosol DA 20% and stroma-free hemoglobin may alter the acetylation of sulfamethazine.

Interaction of oxygen-carrying resuscitation fluids with morphine

The oxygen-carrying resuscitation fluids, Fluosol DA 20% and stroma-free hemoglobin, are currently being evaluated for efficacy and effects in vivo. Because these fluids may be administered to trauma victims, the pharmacokinetics of morphine was studied in rats after transfusion with one of these fluids. During development of high-performance liquid chromatography assay for morphine in plasma, an in vitro interaction between plasma, Fluosol DA, or stroma-free hemoglobin and morphine was observed at pH greater than 10.5. This interaction was dependent on pH and was specific to morphine, compared with codeine. The interaction between stroma-free hemoglobin and morphine appeared to be covalent in nature. The t1/2 of morphine was significantly prolonged from 1.02 +/- 0.50 hours (mean +/- SD) to 2.46 +/- 2.68 hours (p = 0.03) after transfusion with stroma-free hemoglobin, and to 2.05 +/- 0.95 hours (p = 0.006) after transfusion with Fluosol DA. The volume of distribution was increased from 1.35 +/- 0.81 L X kg-1 to 2.99 +/- 1.45 L X kg-1 (p = 0.004) after transfusion with stroma-free hemoglobin; no such difference was observed after transfusion with fluosol DA (p = 0.86). The area under the time-concentration curve was increased from 2.37 +/- 1.78 mg X hr X L-1 to 6.02 +/- 6.61 mg X hr X L-1 (p = 0.02), and total body clearance was decreased from 1.02 +/- 0.53 L X hr-1 X kg-1 to 0.55 +/- 0.36 L X hr-1 X kg-1 (p = 0.01) after transfusion with Fluosol DA. No significant differences were observed in these parameters after transfusion with stroma-free hemoglobin (p = 0.48 and p = 0.81, respectively). These data show that stroma-free hemoglobin prolongs the t1/2 of morphine by altering the volume of distribution. In contrast, Fluosol DA prolongs the t1/2 of morphine by altering the total body clearance. These data may have important therapeutic implications.

Comparative penetration of azlocillin and mezlocillin into cerebrospinal fluid of normal rabbits and rabbits with experimentally induced Pseudomonas aeruginosa meningitis

The impacts of meningeal infection with Pseudomonas aeruginosa and route of drug administration on the penetration of azlocillin and mezlocillin into the cerebrospinal fluid of rabbits were evaluated. The penetration of both agents was increased to a similar degree in rabbits with meningitis compared with normal rabbits. The increase in penetration was greater after intravenous administration than after intramuscular administration.

Central nervous system toxicity of intraventricularly administered gentamicin in adult rabbits

To determine whether daily intraventricular injection of gentamicin sulfate would cause neurologic or morphologic abnormalities of the central nervous system, adult male rabbits were given gentamicin sulfate, 2 mg/kg, intramuscularly twice a day plus saline, 0.2 ml (group 1), or gentamicin, 0.05 mg/kg (group 2), 0.25 mg/kg (group 3), or 0.5 mg/kg (group 4), given as the sulfate intraventricularly once a day. The majority of the animals in group 4 developed neurologic abnormalities which progressed to death in animals that were not euthanized; neuropathologic studies revealed chemical ventriculitis and meningitis that were associated with high levels of gentamicin in the cerebrospinal fluid and tissue of the central nervous system. Similar neurologic and morphologic changes were seen in most animals of group 3 but not in rabbits of groups 1 and 2. The ototoxicity and nephrotoxicity of gentamicin are well known; these data indicate that it may be toxic to the central nervous system as well.

Antigenicity and protective effects of type 3 pneumococcal polysaccharide in rats

The response to type 3 pneumococcal polysaccharide vaccination, the protective effect of type 3 pneumococcal polysaccharide vaccination, and the ability of hemagglutinating antibody to type 3 pneumococcal polysaccharide to cross the blood-brain barrier were studied in rats. Hemagglutinating antibody response to vaccination with type 3 pneumococcal polysaccharide was found to be dependent on the dose and route of inoculation. Intraperitoneal vaccination with type 3 pneumococcal polysaccharide protected the rats from subsequent intraperitoneal challenge with type 3 Streptococcus pneumoniae but had no effect after intracisternal challenge with type 3 S. pneumoniae. In the presence or absence of sterile meningeal inflammation, hemagglutinating antibody could not be found in cerebrospinal fluid of animals vaccinated intraperitoneally with type 3 pneumococcal polysaccharide. These results suggest that type 3 pneumococcal polysaccharide is antigenic in rats and intraperitoneal vaccination with type 3 pneumococcal polysaccharide does not protect against experimental meningitis because antibodies do not cross the blood-brain barrier.