Thomas J. Prihoda

Effectiveness of adenoidectomy and tympanostomy tubes in the treatment of chronic otitis media with effusion

To study the effectiveness of adenoidectomy and of the placement of tympanostomy tubes in the treatment of chronic otitis media with effusion, we randomly assigned 578 children, aged four through eight years, to receive bilateral myringotomy and no additional treatment (Group 1), placement of tympanostomy tubes (Group 2), adenoidectomy (Group 3), or adenoidectomy and placement of tympanostomy tubes (Group 4). The 491 children who underwent one of these treatments were examined at six-week intervals for up to two years. The mean time spent with effusion of any type in either ear over the two-year follow-up in the four groups was 51, 36, 31, and 27 weeks, respectively (P less than 0.0001), comparing Group 1 with each of the other groups. Hearing was equivalent in Groups 2, 3, and 4, and was significantly better than in Group 1. The most frequent sequela, purulent otorrhea, occurred one or more times in 22, 29, 11, and 24 percent of the subjects in Groups 1, 2, 3, and 4, respectively (P less than 0.001). Adenoidectomy plus bilateral myringotomy lowered the overall post-treatment morbidity (as measured by hearing acuity in the most severely affected ear [P = 0.0174] and the number of surgical retreatments required [P = 0.009]) more than did tympanostomy tubes alone and to the same degree as did adenoidectomy and tympanostomy tubes. We conclude that adenoidectomy should be considered when surgical therapy is indicated in children four to eight years old who are severely affected by chronic otitis media with effusion.

Phosphorylation of Akt (Ser473) is an Excellent Predictor of Poor Clinical Outcome in Prostate Cancer

We previously showed, by immunohistochemistry with phospho-specific antibodies, increased phosphorylation (activation) of Akt (Ser473) [phosphorylated Akt (pAkt)] in high-Gleason grade prostate cancer (Malik SN, et al., Clin Cancer Res 2002;8:1168–71). Elevation of pAkt was accompanied by decreased phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 (Thr202/Tyr204) [phosphorylated ERK (pERK)], indicative of inactivation. In this report, we determined whether increased pAkt and decreased pERK predicted clinical outcome. Prostate-specific antigen (PSA) failure (detectable and rising PSA) versus PSA non-failure (undetectable PSA 5 years after prostatectomy) was used as a surrogate for clinical outcome. Prostate tumors from cases of PSA failure versus non-failure were stained for pAkt and pERK. A significant increase in mean pAkt staining (P < 0.001) in the PSA failures versus non-failures was seen based on the Wilcoxon signed ranks test [222.18 ± 33.9 (n = 37) versus 108.79 ± 104.57 (n = 16)]. Using the best-fitting multiple logistic regression equation, a 100-point increase in pAkt staining resulted in a 160% increase in the odds of being a PSA failure. There was decreased staining for pERK in PSA failures versus non-failures: a 100-point decrease resulted in an 80% increase in the odds of being a PSA failure. Each of these effects assumed the other biomarker was held constant. The area under the receiver-operating characteristic curve for these two biomarkers predicting PSA failure was 0.84, indicating excellent discrimination between PSA failure and non-failure cases. These data indicate that increased pAkt, alone or together with decreased pERK, is an important predictor of probability of PSA failure. However, pERK alone was not a significant predictor of PSA failure.

Comparative placental transport of oral hypoglycemic agents in humans: A model of human placental drug transfer

OBJECTIVE This study compares the human placental transport of glyburide, glipizide, chlorpropamide, and tolbutamide. STUDY DESIGN The recirculating single cotyledon human placenta model tested maternal-to-fetal transport in term placentas perfused immediately after delivery. Drug levels were measured by high-performance liquid chromatography and liquid scintillation spectrometry, and transport rates were calculated by comparing maternal and fetal concentrations. RESULTS The transport of these substances differed significantly over a tenfold range (analysis of variance, p < 0.0008). A significant association exists by multiple linear regression between drug transfer and molecular weight, dissociation constant, and the octanol-water partition coefficient (R2 = 0.91, p < 0.0001). CONCLUSIONS There is significant variability in human placental transfer rates of the oral hypoglycemics, which strongly correlates with molecular properties. These data suggest that less fetal exposure may occur with second-generation sulfonylureas and anticipate that regression models may be useful in selecting agents that minimize placental transport to the fetus.

Variations in adult cortical bone mass as measured by a panoramic mandibular index

This study defines a new radiomorphometric index of mandibular cortical bone mass, the panoramic mandibular index (PMI). Differences in the index in a population of 353 adult subjects, equally divided by sex, age (30 through 79 years), and racial group (black, Hispanic, white), were evaluated. The data were analyzed with respect to side, racial group, sex, age, and combinations of these variables. Blacks were found to have a greater mean PMI than Hispanics or whites, who were statistically similar. Age-related changes comparing younger and older age groups within each sex and racial group indicated a significant decrease in mean PMI with increasing age in black and Hispanic women. The mean PMI in white men increased with advancing age.

Determining Risk of Biochemical Recurrence in Prostate Cancer by Immunohistochemical Detection of PTEN Expression and Akt Activation

Purpose: A considerable fraction of patients who undergo radical prostatectomy as treatment for primary prostate cancer experience biochemical recurrence detected by elevated serum levels of prostate-specific antigen. In this study, we investigate whether loss of expression of the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and the phosphorylated form of the cell survival protein Akt (pAkt) predicts biochemical recurrence. Experimental Design: Expression of PTEN and pAkt was detected by immunohistochemistry in paraffin-embedded prostate cancer tissue obtained from men undergoing radical prostatectomy. Outcome was determined by 60-month follow-up determining serum prostate-specific antigen levels. Results: By itself, PTEN was not a good predictor of biochemical recurrence; however, in combination with pAkt, it was a better predictor of the risk of biochemical recurrence compared with pAkt alone. Ninety percent of all cases with high pAkt and negative PTEN were recurrent whereas 88.2% of those with low pAkt and positive PTEN were nonrecurrent. In addition, high Gleason scores resulted in reduced protection from decreased pAkt and increased PTEN. By univariate logistic regression, pAkt alone gives an area under the receiver-operator characteristic curve of 0.82 whereas the area under the receiver-operator characteristic curve for the combination of PTEN, pAkt, and Gleason based on a stepwise selection model is 0.89, indicating excellent discrimination. Conclusions: Our results indicate that loss of PTEN expression, together with increased Akt phosphorylation and Gleason score, is of significant predictive value for determining, at the time of prostatectomy, the risk of biochemical recurrence.

Effect of adenoidectomy upon children with chronic otitis media with effusion

To investigate the mechanism whereby adenoidectomy influences the subsequent course of patients with chronic otitis media with effusion, we analyzed, on the basis of adenoid size, the outcomes of 476 children randomly assigned to receive, after paracentesis and aspiration of the middle ear, either no treatment, tympanostomy tubes, adenoidectomy, or both. The two groups receiving adenoidectomy did significantly better than those who did not, and the effect was independent of adenoid size. This suggests that reduction of the adenoidal bacterial reservoir may be the mechanism whereby adenoidectomy is effective.

Agonist-dependent failure of neutrophil function in diabetes correlates with extent of hyperglycemia.

Inexplicable controversies with regard to possible functional defects of neutrophilic polymorphonuclear leukocytes (PMNs) in diabetes persist. The purpose of the present study was to elucidate the relative effectiveness of several PMN agonists in stimulating lysosomal‐enzyme secretion and leukotriene (LT) B4 production by PMNs isolated from diabetic subjects. Formyl‐methionyl‐leucyl‐phenylalanine (fMLP) and platelet‐activating factor (PAF) induced significantly less lysosomal‐enzyme secretion and LTB4 production in diabetic‐subject PMNs than in normal‐subject PMNs. It is surprising that PMNs from these same diabetic subjects responded normally after stimulation with A23187, serum‐opsonized zymosan, or phorbol myristate acetate. The in vitro responsiveness of PMNs stimulated with fMLP or PAF was inversely correlated with indices of in vivo glycemic control (fasting plasma glucose and glycated‐hemoglobin levels). In combination, these results indicate that hyperglycemia is associated with sustained decreases in PMN function but only in response to agonists that initiate stimulus‐response coupling via G‐protein‐coupled receptors. This agonist‐selective reduction in PMN responsiveness may contribute to the compromised host defense associated with sustained hyperglycemia in diabetes.

Attention-Deficit-Hyperactivity Disorder and Reward Deficiency Syndrome

Molecular genetic studies have identified several genes that may mediate susceptibility to attention deficit hyperactivity disorder (ADHD). A consensus of the literature suggests that when there is a dysfunction in the “brain reward cascade,” especially in the dopamine system, causing a low or hypo-dopaminergic trait, the brain may require dopamine for individuals to avoid unpleasant feelings. This high-risk genetic trait leads to multiple drug-seeking behaviors, because the drugs activate release of dopamine, which can diminish abnormal cravings. Moreover, this genetic trait is due in part to a form of a gene (DRD2 A1 allele) that prevents the expression of the normal laying down of dopamine receptors in brain reward sites. This gene, and others involved in neurophysiological processing of specific neurotransmitters, have been associated with deficient functions and predispose individuals to have a high risk for addictive, impulsive, and compulsive behavioral propensities. It has been proposed that genetic variants of dopaminergic genes and other “reward genes” are important common determinants of reward deficiency syndrome (RDS), which we hypothesize includes ADHD as a behavioral subtype. We further hypothesize that early diagnosis through genetic polymorphic identification in combination with DNA-based customized nutraceutical administration to young children may attenuate behavioral symptoms associated with ADHD. Moreover, it is concluded that dopamine and serotonin releasers might be useful therapeutic adjuncts for the treatment of other RDS behavioral subtypes, including addictions.

Brief Psychiatric Rating Scale Expanded Version: How do new items affect factor structure?

Our goal was to suggest a factor structure for the Brief Psychiatric Rating Scale Expanded Version (BPRS-E) based upon a large and diverse sample and to determine which of the new items improved the factors derived from the 18-item version of the scale that have been used in clinical research for decades. We investigated the consistency of our proposed model over time and across demographic groups. As part of the Texas Medication Algorithm Project, the BPRS-E was administered to a total of 1440 psychiatric outpatients in three different diagnostic groups on multiple occasions. The sample was randomly split so that exploratory factor analysis could be done with the first half, and the model could be confirmed on the second half. A four-factor structure including factors assessing depression/anxiety, psychosis, negative symptoms, and activation was found. For each factor, we specify items in the expanded version that added to the breadth of the commonly used clinical factors while improving or maintaining goodness of fit and reliability. The final model proposed was consistent over time and across diagnosis, phase of illness, age, gender, ethnicity, and level of education. The BPRS-E has a stable four-factor structure, making it useful as a clinical outcome measure.

Nuclear versus cytoplasmic localization of filamin A in prostate cancer: immunohistochemical correlation with metastases.

Purpose: We previously showed that nuclear localization of the actin-binding protein, filamin A (FlnA), corresponded to hormone-dependence in prostate cancer. Intact FlnA (280 kDa, cytoplasmic) cleaved to a 90 kDa fragment which translocated to the nucleus in hormone-naïve cells, whereas in hormone-refractory cells, FlnA was phosphorylated, preventing its cleavage and nuclear translocation. We have examined whether FlnA localization determines a propensity to metastasis in advanced androgen-independent prostate cancer. Experimental Design: We examined, by immunohistochemistry, FlnA localization in paraffin-embedded human prostate tissue representing different stages of progression. Results were correlated with in vitro studies in a cell model of prostate cancer. Results: Nuclear FlnA was significantly higher in benign prostate (0.6612 ± 0.5888), prostatic intraepithelial neoplasia (PIN; 0.6024 ± 0.4620), and clinically localized cancers (0.69134 ± 0.5686) compared with metastatic prostate cancers (0.3719 ± 0.4992, P = 0.0007). Cytoplasmic FlnA increased from benign prostate (0.0833 ± 0.2677), PIN (0.1409 ± 0.2293), localized cancers (0.3008 ± 0.3762, P = 0.0150), to metastases (0.7632 ± 0.4414, P < 0.00001). Logistic regression of metastatic versus nonmetastatic tissue yielded the area under the receiver operating curve as 0.67 for nuclear-FlnA, 0.79 for cytoplasmic-FlnA, and 0.82 for both, indicating that metastasis correlates with cytoplasmic to nuclear translocation. In vitro studies showed that cytoplasmic localization of FlnA induced cell invasion whereas nuclear translocation of the protein inhibited it. FlnA dephosphorylation with the protein kinase A inhibitor H-89 facilitated FlnA nuclear translocation, resulting in decreased invasiveness and AR transcriptional activity, and induced sensitivity to androgen withdrawal in hormone-refractory cells. Conclusions: The data presented in this study indicate that in prostate cancer, metastasis correlates with cytoplasmic localization of FlnA and may be prevented by cleavage and subsequent nuclear translocation of this protein.