Jorge Gutierrez

Recent studies have suggested that periodontal disease is a risk factor for preterm low birth weight (PLBW). A randomized controlled trial was undertaken to help further evaluate the proposed association between periodontal disease and PLBW. Four hundred pregnant women with periodontal disease, aged 18 to 35, were enrolled while receiving prenatal care in Santiago, Chile. Women were randomly assigned to either an experimental group (n = 200), which received periodontal treatment before 28 weeks of gestation or to a control group (n = 200) which received periodontal treatment after delivery. Previous and current pregnancies and known risk factors were obtained from patient medical records and interviews. The primary outcome assessed was the delivery at less than 37 weeks of gestation or an infant weighing less than 2,500 g. Of the 400 women enrolled, 49 were excluded from the analyses for different reasons. The incidence of PLBW in the treatment group was 1.84% (3/163) and in the control group was 10.11% (19/188), (odds ratio [OR] 5.49, 95% confidence interval [CI] 1.65 to 18.22, P= 0.001). Multivariate logistic regression analysis showed that periodontal disease was the strongest factor related to PLBW (OR 4.70, 95% CI 1.29 to 17.13). Other factors significantly associated with such deliveries were: previous PLBW (OR 3.98, 95% CI 1.11 to 14.21), less than 6 prenatal visits (OR 3.70, 95% Cl 1.46 to 9.38), and maternal low weight gain (OR 3.42, 95% CI 1.16 to 10.03). Periodontal disease appears to be an independent risk factor for PLBW. Periodontal therapy significantly reduces the rates of PLBW in this population of women with periodontal disease.

The differentiation of tumor recurrence from radiation necrosis in patients with malignant gliomas who have been treated previously remains a challenge. Magnetic resonance imaging, single-photon emission computed tomography, and positron emission tomography cannot provide definitive histopathological insight. Multivoxel proton magnetic resonance spectroscopic imaging ((1)H MRSI) may be reliable in guiding the clinical management of untreated patients; however, its value in managing previously treated patients remains unclear. Twenty-seven patients who had been treated previously with surgery, radiotherapy, and chemotherapy and reoperated for clinical and/or radiographic signs that caused suspicion for recurrent disease were studied. Tissues were categorized into four groups: spectroscopically normal, pure tumor, mixed tumor and radiation necrosis, and pure radiation necrosis. Spectral data for choline (Cho), lipid-lactate (Lip-Lac), N-acetylaspartate, and creatine (Cr) were analyzed as Cho/normal Cr (nCr), Lip-Lac/Cho, Lip-Lac/nCr, N-acetylaspartate/Cho, N-acetylaspartate/nCr, and Cho/normal Cho (nCho). Stereotactic biopsies were obtained within 48 hours of (1)H MRSI and were directly correlated digitally with (1)H MRSI data. Logistic regression analysis was performed on the basis of data obtained from 99 (1)H MRSI observations to determine whether the (1)H MRSI ratios varied according to tissue category. (1)H MRSI ratios were found to distinguish pure tumor from pure necrosis. The odds of a biopsy's being pure tumor and having either a Cho/nCr value greater than 1.79 or a Lip-Lac/Cho value less than 0.75 are seven times the odds of that biopsy's being pure necrosis (odds ratio, 7.00; P = 0.0136). The odds of a biopsy's being pure necrosis and having either a Cho/nCr value less than 0.89 or a Cho/nCho value less than 0.66 are six times the odds of that biopsy's being pure tumor (odds ratio, 5.71; P = 0.0329). The odds of a biopsy's being pure necrosis and having either a Lip-Lac/Cho value greater than 1.36 or a Lip-Lac/nCr value greater than 2.84 are more than five times the odds of the…

Background Cerebral radiation necrosis is a serious complication of radiation treatment for brain tumors. Therapeutic options include corticosteroids, anticoagulation and hyperbaric oxygen with limited efficacy. Bevacizumab, an antibody against VEGF had been reported to reduce edema in patients with suspected radiation necrosis. We retrospectively reviewed 6 patients with biopsy proven cerebral radiation necrosis treated with bevacizumab between 2006 and 2008. Results Interval MRI follow-up demonstrated radiographic response in all patients with an average reduction of 79% for the post gadolinium studies and 49% for the FLAIR images. The initial partial radiographic response was noted for up to a mean follow-up time of 5.9 months (6 weeks to 18 months). Conclusion Bevacizumab appears to produce radiographic response and clinical benefits in the treatment of patients with cerebral radionecrosis.

Since intratumoral heterogeneity of gliomas is not adequately reflected in conventional magnetic resonance imaging (MRI), we sought to determine a correlation between different proton magnetic resonance spectroscopic imaging ((1)H MRSI) metabolic ratios and the degree of tumor infiltration in diffusely infiltrating gliomas. In this report, we describe the microscopic anatomy of gliomas on imaging. Image-guided biopsies with semiquantitative and qualitative histopathological analyses from a series of 31 untreated patients with low- and high-grade gliomas were correlated with multivoxel (1)H MRSI referenced to the same spatial coordinates. This series yielded 247 tissue samples and 307 observations. Choline-containing compounds using contralateral creatine and choline for normalization or ipsilateral N-acetylaspartate appear to correlate best with the degree of tumor infiltration. Similar correlations were present within each grade after stratification. Despite the interpatient overlap of metabolic ratios between normal tissue and mild tumor infiltration, preliminary analyses revealed that (1)H MRSI appears more accurate than conventional MRI in defining the tumor boundary and quantifying the degree of tumor infiltration. This is the first study showing histopathological validation of tumor boundaries using (1)H MRSI. These results support the conclusion that (1)H MRSI accurately reflects the extent of the disease in patients with gliomas. This has important diagnostic and therapeutic implications for more accurately assessing the burden of disease as well as for planning and assessing response to therapy.

In patients with malignant glioma previously treated with surgery, radiation, and chemotherapy, clinical and radiographic signs of recurrent disease often require differentiation between radiation necrosis and recurrent tumor. Published work suggests that although magnetic resonance spectroscopy (MRS) can reliably differentiate pure tumor, pure necrosis, and spectroscopically normal tissues, it may not be particularly helpful because most patients have mixed histological findings comprised of necrosis and tumor. To improve our clinical ability to discriminate among these histological entities, we have analyzed MRS in conjunction with apparent diffusion coefficient (ADC) sequences derived from magnetic resonance imaging. In 18 patients, spectroscopic and diffusion-weighted images were obtained before surgery for suspected recurrent neoplastic disease. Spectral data for pure tumor, pure necrosis, and mixed tumor and necrosis were derived from 65 spectroscopic observations in patients with previously treated gliomas (n = 16) and metastatic tumors (n = 2). Spectral data for choline (Cho), N-acetylaspartate (NAA), creatine (Cr), and lipid-lactate were analyzed separately and in conjunction with ADCs in all patients (15 observations of pure tumor, 33 observations of pure necrosis, and 13 observations of mixed tumor and necrosis). Histological specimens were obtained stereotactically at the time of surgery (<48 h after image acquisition) for recurrent disease and digitally co-registered with MRS data. ADC values for pure tumor, pure necrosis, and mixed tumor and necrosis were 1.30, 1.60, and 1.42, respectively. Cho/NAA less than 0.20, NAA/normal Cr greater than 1.56, and NAA/Cho greater than 1.32 increase the odds that a tissue biopsy will be pure necrosis versus mixed tumor and necrosis. Although various values of all MRS ratios analyzed may provide positive correlations for histopathological differentiation of tissue between that of pure tumor and that of pure necrosis, the addition of ADC values to only NAA/Cho and NAA/normal Cr increases the odds of correct differentiation between pure tumor and pure necrosis. The addition of ADC values does not provide additional information beyond that of MRS in distinguishing specimens of mixed tumor and necrosis from either pure tumor or pure necrosis. It has been demonstrated that MRS ratio analysis may allow for the clinical discrimination between specimens of pure tumor and pure necrosis, and the addition of ADC data into this analysis may enhance this specific differentiation. However, although a trend toward correlation between ADC values and the various histopathological features was noted, the direct addition of ADC data does not seem to allow further discrimination, beyond that provided by MRS, among specimens of mixed tumor and necrosis and either pure tumor or pure necrosis.