Model-free sib-pair linkage analysis: combining full-sib and half-sib pairs

When sampling full-sibs for linkage studies, half-sibs are often available. Not only are half-sibs convenient to sample, but they can sometimes offer greater power than full-sibs. We propose a method to combine the information from full-sibs and half-sibs into a single test for linkage. This method is based on the Haseman and Elston [1972] method of regressing the squared trait-difference for a pair of sibs (either full- or half-sibs) on the estimated proportion of alleles shared identical by descent. To approximate the distribution of the test statistic, we propose a correction factor that considers the correlation among sibs, and demonstrate by simulations that this approximation works well in many situations, although there are some conditions for which the statistic can have an inflated Type-I error rate. The main appeal of our proposed method is the speed at which it can be computed, offering a rapid way to perform genome-wide linkage screens.

Threshold of toxicological concern for chemical substances present in the diet: a practical tool for assessing the need for toxicity testing

The de minimis concept acknowledges a human exposure threshold value for chemicals below which there is no significant risk to human health. It is the underlying principle for the US Food and Drug Administration (FDA) regulation on substances used in food-contact articles. Further to this, the principle of Threshold of Toxicological Concern (TTC) has been developed and is now used by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in their evaluations. Establishing an accepted TTC would benefit consumers, industry and regulators, since it would preclude extensive toxicity evaluations when human intakes are below such threshold, and direct considerable time and cost resources towards testing substances with the highest potential risk to human health. It was questioned, however, whether specific endpoints that may potentially give rise to low-dose effects would be covered by such threshold. In this review, the possibility of defining a TTC for chemical substances present in the diet was examined for general toxicity endpoints (including carcinogenicity), as well as for specific endpoints, namely neurotoxicity and developmental neurotoxicity, immunotoxicity and developmental toxicity. For each of these endpoints, a database of specific no-observed-effect levels (NOELs) was compiled by screening oral toxicity studies. The substances recorded in each specific database were selected on the basis of their demonstrated adverse effects. For the neurotoxicity and developmental neurotoxicity databases, it was intended to cover all classes of compounds reported to have either a demonstrated neurotoxic or developmentally neurotoxic effect, or at least, on a biochemical or pharmacological basis were considered to have a potential for displaying such effects. For the immunotoxicity endpoint, it was ensured that only immunotoxicants were included in the database by selecting most of the substances from the Luster et al. database, provided that they satisfied the criteria for immunotoxicity defined by Luster. For the developmental toxicity database, substances were selected from the Munro et al. database that contained the lowest NOELs retrieved from the literature for more than 600 compounds. After screening these, substances showing any effect which could point to developmental toxicity as broadly defined by the US were recorded in the database. Additionally, endocrine toxicity and allergenicity were addressed as two separate cases, using different approaches and methodology. The distributions of NOELs for the neurotoxicity, developmental neurotoxicity and developmental toxicity endpoints were compared with the distribution of NOELs for non-specific carcinogenic endpoints. As the immunotoxicity database was too limited to draw such a distribution of immune NOELs, the immunotoxicity endpoint was evaluated by comparing immune NOELs (or LOELs-lowest-observed-effect levels-when NOELs were not available) with non-immune NOELs (or LOELs), in order to compare the sensitivity of this endpoint with non-specific endpoints. A different methodology was adopted for the evaluation of the endocrine toxicity endpoint since data currently available do not permit the establishment of a clear causal link between endocrine active chemicals and adverse effects in humans. Therefore, this endpoint was analysed by estimating the human exposure to oestrogenic environmental chemicals and evaluating their potential impact on human health, based on their contribution to the overall exposure, and their estrogenic potency relative to endogenous hormones. The allergenicity endpoint was not analysed as such. It was addressed in a separate section because this issue is not relevant to the overall population but rather to subsets of susceptible individuals, and allergic risks are usually controlled by other means (i.e. labelling) than the Threshold of Toxicological Concern approach. (ABSTRACT TRUNCATED)

Accuracy and clinical impact of mediastinal lymph node staging with FDG-PET imaging in potentially resectable lung cancer

To determine the sensitivity, specificity, and accuracy of staging mediastinal nodal disease in potentially resectable lung cancer using fluorodeoxyglucose-positron emission tomography (FDG-PET), computed tomography (CT), or both and compare these results to surgical staging. We also assessed whether PET scanning results changed clinical management. From 1992 to 1997, 50 patients underwent CT, and PET scanning before or close to the time of surgical staging. Sensitivity, specificity, accuracy, and predictive values were then calculated based on pathology results. A retrospective review of the records was performed to determine how PET results affected clinical treatment decisions. Forty-seven of 50 patients had non-small-cell lung cancer. The prevalence of pathologically confirmed mediastinal and hilar involvement was 38%. The sensitivity, specificity, and accuracy of mediastinal disease staging were as follows: CT alone = 73%, 77%, 76%; PET alone = 73%, 94%, 87%; PET + CT = 82%, 96%, 91%, respectively. PET was more specific and accurate than CT (p = 0.025). The results of PET changed management decisions in 12 of 50 cases (24%). Using FDG-PET in conjunction with CT scanning provides the most accurate staging of mediastinal disease in lung cancer by contributing complementary information. Furthermore, PET can affect clinical decision-making and allow some patients considered unresectable a chance for resection.

Childhood-onset schizophrenia: progressive brain changes during adolescence

BACKGROUND

Previous NIMH childhood onset schizophrenia (COS) anatomic brain MRI studies found progression of ventricular volume and other structural brain anomalies at 2-year follow up across mean ages 14 to 16 years. However, studies in adult patients generally do not show progression of ventricular volume or correlation of ventricular volume with duration of illness. To address issues of progression of brain anomalies in schizophrenia, this report extends previous studies to include a third longitudinal scan, uses a larger sample size, and includes measures of the amygdala and hippocampus.

METHODS

Volumes of the total cerebrum, lateral ventricles, hippocampus, and amygdala were quantified on 208 brain magnetic resonance imaging scans from 42 adolescents with COS (23 with one or more repeat scan) and 74 age- and gender-matched controls (36 with one or more repeat scan). A statistical technique permitting combined use of cross-sectional and longitudinal data was used to assess age-related changes, linearity, and diagnostic group differences.

RESULTS

Differential nonlinear progression of brain anomalies was seen during adolescence with the total cerebrum and hippocampus decreasing and lateral ventricles increasing in the COS group. The developmental curves for these structures reached an asymptote by early adulthood for the COS group and did not significantly change with age in the control group.

CONCLUSIONS

These findings reconcile less striking progression of anatomic brain images usually seen for adult schizophrenia and complement other data consistent with time-limited, diagnostic-specific decreases in brain tissue. Adolescence appears to be a unique period of differential brain development in schizophrenia.

Filgrastim (r-metHuG-CSF) and its potential use in the reduction of radiation-induced oropharyngeal mucositis: an interim look at a randomized, double-blind, placebo-controlled trial

We wished to determine if filgrastim administration to chemotherapy/radiation therapy-naive patients receiving external-beam irradiation for head-and-neck malignancies would reduce the incidence and severity of oral/oropharyngeal mucositis. Patients were randomized to receive subcutaneous injections of either filgrastim or placebo beginning on day 1 of radiation and continuing daily throughout treatment. Study medication was titrated to keep the neutrophil count between 10 x 10(9) and 30 x 10(9)/l. The left and right buccal mucosa, hard palate, and posterior pharyngeal wall were scored weekly, by a blinded evaluator using two different scales, and the most severe score per week was used in data analysis. Fourteen of a planned 54 patients were randomized (8 filgrastim, 6 placebo), and were evaluable for a planned interim analysis. No statistically significant between-group differences were seen in mean worst scores across time using repeated measures analysis of variance (Hickey, p = 0.231; WHO, p= 0.288). At almost all timepoints, however, the worst mean scores were lower in patients treated with filgrastim compared with those in patients treated with placebo, and the number of severe (i.e., grade 3) mucositis scores was significantly lower in the filgrastim-treated group. Filgrastim may decrease the severity of radiation-induced oral/oropharyngeal mucositis.

A comparison of mixed effects logistic regression models for binary response data with two nested levels of clustering

We compare mixed effects logistic regression models for binary response data with two nested levels of clustering. The comparison of these models occurs in the context of developmental toxicity data sets, for which multiple types of outcomes (first level) are measured on each rat pup (second level) nested within a litter (third level). Because the nested nature of such data is occasionally accommodated by ignoring one level of clustering, we consider three models: (i) a three-level model adjusting for clustering due to both pup and litter (M1); (ii) a two-level model adjusting for just pup (M2); and (iii) another two-level model adjusting for just litter (M3). The three types of effects of interest are: (i) differences among malformation types (first-level effects); (ii) differences among groups of pups (for example, sex of pup, second-level effects); and (iii) differences among groups of litters (for example, dose, third-level effects). Simulations and data analyses suggest that the M3 model leads to more bias than the M1 or M2 models for all three types of effects. In terms of coverage of confidence intervals for fixed effects log odds ratio parameters, the M1 model achieves nominal coverage, whereas the M2 model reduces coverage for the third-level effects and the M3 model obtains poor coverage for both first- and second-level effects. These reductions in coverage for certain model-parameter combinations worsen as baseline risk increases. The data analyses support these simulation-based conclusions to some extent.

Ex vivo expansion and differentiation of unselected peripheral blood progenitor cells in serum-free media

The ability to expand and differentiate unselected PBPC was investigated. Cells were grown in serum-free media containing stem cell factor, GCSF and megakaryocyte growth and development factor (pegylated PEG-rHuMGDF) with or without supplemental serum. Optimal proliferation occurred when PBPC were cultured without prior Ficoll-Paque separation in serum-free media. Cell yields after 17 days of culture were proportional to the percentage of CD34+ cells in the starting population and were 1170+/-302-fold higher than the starting numbers of CD34+ cells. Granulocyte-macrophage colony-forming units increased over 12 days of culture, whereas the numbers of erythroid colony-forming cells peaked between 4 and 7 days. Elimination of PEG-rHuMGDF from cell cultures resulted in significantly lower yields of myeloid and erythroid colony-forming cells and total cell numbers. Cell differentiation into neutrophils was indicated by progressive increases in CD11b, CD15, and CD66b expression. Expanded neutrophils phagocytosed and killed bacteria as efficiently as neutrophils from normal donors. Large-scale expansion studies yielded similar proliferation and differentiation results as parallel small-scale cultures. Therefore, unselected PBPC can be efficiently expanded and differentiated into large numbers of functional mature neutrophils.

Interferon-alpha and granulocyte-macrophage colony-stimulating factor differentiate peripheral blood monocytes into potent antigen-presenting cells

The diverse roles of interferon-alpha (IFN-alpha) in regulating the immune response to infectious agents suggested that it might affect dendritic cell (DC) development. Peripheral blood mononuclear cells cultured with IFN-alpha and granulocyte-macrophage colony-stimulating factor (GM-CSF) developed a dendritic morphology and expressed high levels of the class I and II human leukocyte antigens (HLA), B7 co-stimulatory molecules, adhesion proteins, and CD40. Elevated DC expression of B7-2 and HLA-DR was observed with increasing IFN-alpha concentrations up to 5000 U/mL. The effects of IFN-alpha on DC immunophenotype were not reversed by adding neutralizing antibodies against interleukin-4 (IL-4) or tumor necrosis factor alpha to the cell cultures or by eliminating lymphocytes from the cultures. The addition of IFN-alpha to cultures containing optimal concentrations of IL-4 and GM-CSF significantly increased the B7-2 and HLA-DR levels above those present on DCs grown in two cytokines. The DCs generated with IFN-alpha and GM-CSF were potent antigen-presenting cells in allogeneic mixed leukocyte reactions. They also were capable of taking up, processing, and presenting tetanus toxin to autologous T lymphocytes. These results demonstrate an important role for IFN-alpha in the generation of DCs with potent antigen-presenting capabilities from peripheral blood monocytes.

Salvage radiotherapy for biochemical and clinical failures following radical prostatectomy

PURPOSE

The proportion of prostate cancer patients undergoing radical prostatectomy has increased over the past 10 to 15 years. It is conceivable that a corresponding increase in local tumor recurrences after prostatectomies will be observed. The role of salvage radiotherapy is presently unclear. In this study, the results of salvage radiotherapy for patients with biochemical evidence of local recurrence, as evidenced from rising prostate-specific antigen (PSA) levels, after radical prostatectomy at UCLA Medical Center and the West Los Angeles Veterans Administration Medical Center are described.

PATIENTS AND METHODS

Between 1990 and 1997, 69 patients were diagnosed with presumed local tumor recurrence after radical prostatectomy. Of these patients, 60 patients were referred to radiotherapy for salvage treatments. Tumor recurrence was detected biochemically, with or without a palpable nodule on digital rectal examination, and a metastatic workup revealing no evidence of extrapelvic disease. Biochemical failure after salvage radiotherapy was defined as two consecutive rises in serum PSA level after a PSA nadir or an absence of a PSA nadir after radiation treatments, as was earlier defined at the ASTRO Consensus Panel on PSA Guidelines. Patients referred for adjuvant postoperative radiation treatment and patients with metastatic disease at presentation were excluded from the study. Patients were treated with a four-field approach (anteroposterior/posteroanterior and opposing laterals) to a median dose of 64.8 Gy in 1.8-Gy fractions. Follow-up evaluations included serum PSA level and digital rectal examination every 3 to 6 months.

RESULTS

At last follow-up (mean follow-up, 36 months after salvage radiotherapy), 40 of 60 patients (67%) were biochemically free of disease. Thirty of 60 patients (50%) had undetectable PSA levels, and 55 of 60 (92%) had achieved some initial decrease after salvage radiation treatments. Three-year and 5-year actuarial biochemical disease-free survival was 63% and 55%, respectively. Of the 20 patients with biochemical failure after salvage radiation therapy, 10 patients (50%) developed distant metastases, and two (10%) patients were found to have persistent local disease. The mean time to biochemical relapse after salvage radiotherapy was 10 months, and the mean time to distant metastasis after salvage radiotherapy was 20 months. Evaluation of the remaining eight biochemical failures (43%) revealed no evidence of local disease progression or distant metastasis to date. Univariate and multivariate analyses revealed that both PSA > 1.0 ng/mL at the time of salvage radiotherapy and perineural invasion significant prognosticators for biochemical relapse after salvage radiotherapy. Likewise, both univariate and multivariate analyses revealed that prognosticators for distant metastasis included seminal vesicle invasion and perineural invasion.

DISCUSSION

Salvage radiation therapy is a viable option for post prostatectomy local tumor recurrences. Of the patients who fail biochemically after salvage radiotherapy, 50% were eventually found to have distant metastases. In addition, biopsy-proven local recurrence after-prostatectomy was found not to confer an adverse outcome after salvage radiotherapy.

Evidence for selective degradation of platelet GP IIb/IIIa complex after prolonged in vitro ventricular assist

BACKGROUND

Left ventricular assist devices (VAD) have improved survival in patients with end-stage heart failure. Past studies have shown that interactions between blood and synthetic surfaces promote initial bleeding and later thromboembolism. The exact mechanism of blood activation during VAD circulation remains unclear. The purpose of this study was to test the hypothesis that platelet glycoprotein (GP) IIb/IIIa receptor degradation occurs during clinical use of ventricular assist devices.

METHODS

Five in vitro nonpulsatile centrifugal VAD circuits were simulated for 4 days using 450 mL of fresh human whole blood. Temperature, activated clotting time, pH, pCO2, pO2, Ca++, and glucose were maintained at physiologic values. Flow was maintained at a constant 2.0 L/min/m2. We examined whole blood platelet aggregation induced by ristocetin, collagen, and adenosine diphosphate (ATP). We also examined whole blood platelet degranulation induced by collagen and ADP.

RESULTS

Platelet aggregation in response to ristocetin, collagen, and ADP irreversibly and progressively declined with prolonged circulation in the VAD. While ADP-induced aggregation declined within the first hour, ristocetin and collagen-induced aggregation declined after 10 hours. Collagen-induced platelet degranulation decreased similar to aggregation, whereas ADP-induced degranulation continued and was preserved throughout the experiment.

CONCLUSIONS

These results suggest prolonged circulation of human blood in a VAD circuit irreversibly impair platelet aggregation. The response of circulating platelets to individual agonists suggests that this platelet degradation is partially receptor specific. In our VAD system, ADP-stimulated platelet aggregation is more rapidly degraded with circulation. These results offer preliminary evidence that circulation of human blood in a VAD circuit leads to early degradation of the platelet GP IIb/IIIa complex. GP IIb/IIIa complex degradation is likely to be the mechanism of early VAD associated bleeding.

Thrombotic microangiopathy following allogeneic bone marrow transplantation is associated with intensive graft-versus-host disease prophylaxis

Thrombotic microangiopathy (TM), manifesting clinically as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome, is an uncommon complication after bone marrow transplantation (BMT). A retrospective analysis of potential risk factors for TM following allogeneic BMT was performed. Clinical data were analyzed from seven patients diagnosed with severe TM and 409 patients who underwent BMT during the same time period and who survived for at least 100 days afterwards. Six of the seven patients with TM received intensive GVHD prophylaxis consisting of cyclosporine, methotrexate and glucocorticoids, whereas only 66 of the 409 patients without TM received this regimen (P < 0.001, Fisher's exact test). This regimen was administered to patients older than 40 years, or recipients of a mismatched or unrelated allograft. Univariate analysis also revealed an increased risk of TM associated with the use of an unrelated bone marrow donor (P = 0.02), but no significant association with patient age or gender, diagnosis, amount of prior chemotherapy, transplant conditioning regimen or severity of GVHD. A multivariate exact logistic regression analysis revealed that only the type of GVHD prophylaxis had a significant impact on the risk for TM. The combined use of cyclosporine, methotrexate and glucocorticoids as GVHD prophylaxis may predispose to the development of TM following BMT.

Hepatitis C virus infection in acquired aplastic anemia

Hepatitis-associated aplastic anemia (HAAA) is an uncommon disorder that usually is not due to hepatitis A or B virus infection. Hepatitis C virus (HCV) seropositivity is infrequently observed in aplastic anemia (AA) patients who have not been extensively transfused. However, HCV seropositivity may not be detected until several weeks or months after viral infection and AA patients may exhibit defective humoral immunity. Therefore, we evaluated sera from AA patients for the presence of HCV viremia using a reverse transcriptase polymerase chain reaction (RT-PCR) based assay and several serologic assays for HCV antibodies. Serum samples from 90 AA patients who presented to the UCLA Medical Center between March 1984 and February 1990 were analyzed. Overall, 17 patients were found to have HCV viremia by RT-PCR assay, of whom 14 had a positive second-generation HCV enzyme immunoassay (EIA-2) and only 6 were EIA-1 reactive. The frequency of HCV viremia increased with the duration of time between diagnosis and sample procurement, and the number of blood products transfused prior to sampling (P = 0.026). No patient who received fewer than 20 U of blood products or who was sampled less than 20 days after diagnosis had a positive HCV RT-PCR result. Of four patients with hepatitis-associated AA (HAAA), one who was sampled 23 days after diagnosis had hepatitis C viremia and a reactive EIA-2 assay. Therefore, the high frequency of HCV viremia in this patient population is most likely due to transfusion with contaminated blood products prior to the introduction of routine blood donor screening for HCV.

Synthesis and cleavage of oligodeoxynucleotides containing a 5-hydroxyuracil residue at a defined site

Oxidation and hydrolysis of a cytosine residue can lead to the formation of 5-hydroxyuracil in DNA. The biological consequences of this modification are not fully understood. To facilitate biochemical and biophysical studies aimed at elucidating the effects of this modification in DNA, we have developed a solid-phase synthetic method for the placement of 5-hydroxyuracil residues at defined sites in oligodeoxynucleotides. This method is based upon the enhanced acidity of the 5-hydroxyl proton which allows selective aqueous acetylation. Under standard aqueous ammonia deprotection conditions, however, we observed that 5-hydroxyuracil residues are lost substantially from synthetic oligonucleotides. Substitution of aqueous ammonia with methanolic potassium carbonate and the use of phosphoramidite derivatives with alternatively protected amino groups allow synthesis of oligonucleotides containing 5-hydroxyuracil and all normal bases in high yield. The composition of the oligodeoxynucleotides prepared by this method has been verified by enzymatic digestion followed by high-performance liquid chromatography (HPLC) analysis as well as acid hydrolysis followed by GC/MS analysis. The location of the 5-hydroxyuracil residue is demonstrated by selective permanganate oxidation of the 5-hydroxyuracil residue followed by beta-elimination. We have also probed a synthetic oligonucleotide containing a unique 5-hydroxyuracil residue with uracil DNA N-glycosylase, previously reported to remove this lesion from DNA.

Thrombin causes a marked delay in skeletal myogenesis that correlates with the delayed expression of myogenin and p21CIP1/WAF1

Thrombin is a multifunctional serine protease whose activity is regulated in the extravasculature by an extracellular inhibitor, protease nexin-1. Because protease nexin-1 expression has been shown to be regulated during skeletal muscle cell differentiation, we reasoned that thrombin inactivation may be an important requirement for this developmental process. To test this hypothesis, we examined the effects of thrombin on differentiating C2C12 myoblasts. We report here that myogenesis, as scored by myotube formation, is considerably delayed by thrombin. This regulation correlated with delayed expression of myogenin and p21(CIP1/WAF1), both considered critical components of the skeletal muscle cell differentiation program. Regulation occurred at the RNA level, indicating that the effect of thrombin is either transcriptional or post-transcriptional. Furthermore, we present evidence suggesting that this regulation is mediated by the thrombin receptor. Although thrombin is mitogenic for certain cell types, we found that delay of myogenesis in C2C12 cells did not involve a mitogenic signal. Taken together, these results imply that inhibition of the serine protease thrombin may be required for proper progression through the myogenic differentiation program. The data point to potentially important roles that thrombin and protease nexin-1 may play during skeletal muscle development.

Preparation and ESR spectroscopic characterization of the zinc(II) and cadmium(II) complexes of streptonigrin semiquinone

Semiquinone metal complexes derived from the antitumor antibiotic streptonigrin have been prepared for the first time. They were obtained by reduction of the zinc(II) and cadmium(II) complexes of the parent aminoquinone ligand with sodium borohydride, followed by air oxidation of the intermediate dihydroquinones. Alternatively, N-benzyldihydronicotinamide reduction was used to produce the same Cd(II) complex of the p-semiquinone free radical. Electron spin resonance spectroscopic studies showed that metal binding significantly changes the spin densities of the unpaired electron which is confined to the quinolinesemiquinone moiety of the complexed antibiotic. Complexation with both Cd(II) and Zn(II) perturbs the coupling constants of all atoms involved in delocalization of the unpaired electron, shifting its distribution toward the pyridine ring. The coupling constant of the pyridine ring-proton adjacent to the semiquinone ring increases from 0.31 to 0.43 G in the Cd(II) complex in methanol, while the proton meta to the pyridine nitrogen increases from 1.76 to 1.96 G. Furthermore, the coupling constant of the heterocyclic nitrogen increases from 0.46 to 0.61 G. A similar trend is noted for the Zn(II) complex as well, including the observed decrease in splitting constant of the amino nitrogen from 1.34 to 1.08 G, and perturbation of the previously equivalent amino protons from 0.89 and 0.89 to 1.09 and 0.95 G. The spectral parameters have been confirmed by deuteration. Complexation studies using isotopically enriched 113Cd(II) revealed hyperfine coupling of the unpaired electron of the p-semiquinone and the nuclear spin of 113Cd(II), indicating direct coordination between the metal and the complexing ligand. Although the metal complexes could readily be prepared in a series of different solvent systems, they appear to have substantially shorter half lives than the non complexed p-semiquinone radical (5 to 15 min vs. 2 to 3 wk in sealed ampoules). Formation of tight-binding p-semiquinone metal complexes as here described should provide useful leads for the design of related systems to study p-quinone-metal interactions for mechanistic elucidation of metal ion catalyzed quinone-dependent electron transfer reactions in biological oxidations.

Age-related changes in trabecular cells in vitro

The changes in the morphology and the amounts of selected extracellular matrix proteins in serially passaged porcine trabecular cells cultured from young animals (age range, 4-6 months) were investigated. After 4 weeks incubation, trabecular cells in primary confluent cultures had a flattened elongated profile, whereas the cells in secondary or tertiary cultures, after an additional 4 to 8 weeks incubation, respectively, were epithelioid in shape. Time-lapse micrography of the passaged cells revealed membrane ruffling at the cell periphery, but sparse cell movement. No mitotic events took place in either the secondary or tertiary cultures for 24 hr prior to harvesting the cells. No remarkable differences were observed in the total polypeptide profile of primary, secondary or tertiary cells analysed by SDS gel electrophoresis and silver staining. However, laser densitometry of immunoblots treated with antibodies against type VI collagen, thrombospondin, fibronectin, and laminin demonstrated that, compared to primary cultures of trabecular cells, the amount of type VI collagen was elevated 20.5-fold in tertiary cultures, thrombospondin 6-fold, and fibronectin 5-fold, but laminin was not detectable. Because aging trabecular cells in vitro exhibit specific biochemical characteristics that are comparable to those known to occur in the human trabecular meshwork in vivo, the present method provides a model for the investigation of age-related changes in this tissue at the cellular level under defined and controlled conditions.

Glucose is arrhythmogenic in the anoxic-reoxygenated embryonic chick heart

Unlike in adult heart, embryonic myocardium works at low PO2 and depends preferentially on glucose. Therefore, activity of the embryonic heart during anoxia and reoxygenation should be particularly affected by changes in glucose availability. Hearts excised from 4-d-old chick embryos were submitted in vitro to strictly controlled anoxia-reoxygenation transitions at glucose concentrations varying from 0 to 20 mmol/L. Spontaneous and regular heart contractions were detected optically as movements of the ventricle wall and instantaneous heart rate, amplitude of contraction, and velocities of contraction and relaxation were determined. Anoxia induced transient tachycardia and rapidly depressed contractile activity, whereas reoxygenation provoked a temporary and complete cardioplegia (oxygen paradox). In the presence of glucose, atrial rhythm became irregular during anoxia and chaotic-periodic during reoxygenation. The incidence of these arrhythmias depended on duration of anoxia, and no ventricular ectopic beats were observed. Removal of glucose or blockade of glycolysis suppressed arrhythmias. These results show similarities but also differences with respect to the adult heart. Indeed, glucose 1) delayed and anoxic contractile failure, shortened the reoxygenation-induced cardiac arrest, and improved the recovery of contractile activity; 2) attenuated stunning at 20 mmol/L but worsened it at 8 mmol/L; and 3) paradoxically, was arrhythmogenic during anoxia and reoxygenation, especially when present at the physiologic concentration of 8 mmol/L. The last named phenomenon seems to be characteristic of the young embryonic heart, and our findings underscore that fluctuations of glycolytic activity may play a role in the reactivity of the embryonic myocardium to anoxiareoxygenation transitions.

Urethrography and ischial intertuberosity line in radiation therapy planning for prostate carcinoma

We analyzed our urethrography procedure regarding the validity of using the ischial tuberosity line (ITL) as the caudal margin of treatment portals for prostate carcinoma. The distances of the external urethral sphincter and the lowest margin of the opacified urinary bladder were analyzed in one hundred fifteen consecutive urethrograms. None showed the urethral sphincter to be caudal to the ITL. Ten percent of the sphincters were located less than 1.0 cm cephalad to the ITL, yielding inadequate treatment coverage if the ITL was relied on. Arbitrarily considering 2.0 cm or more of the urethral irradiation to be excessive, the use of the ITL would then have resulted in unnecessary normal tissue irradiation of 42.5%. The ITL should not be used as the caudal margin for prostate treatment portals. Variation in sphincter position, as also seen on lateral projections, reveal a need for urethrography as a necessary supplement to computed tomography to plan radiation portals for prostate cancer.

Sarcomas of the nasal cavity and paranasal sinuses

Sarcomas of the nose and paranasal sinuses are rare malignancies. Key issues remain unresolved in the management of these tumors, particularly with regard to the role of radiotherapy. To help clarify these issues, 48 consecutive cases of nasal and paranasal sinus sarcomas treated at the University of California, Los Angeles, between 1958 and 1988 were retrospectively reviewed. Six of 16 patients managed initially with surgery alone were cured. All had negative surgical margins and 5 of the 6 had low-grade tumors. Of 5 patients with high-grade lesions treated with surgery only, 1 was rendered free of disease. Twelve patients with positive surgical margins were treated with adjuvant radiotherapy; 5 were cured with this approach. Grade and surgical margin status were found to be significantly related to outcome for sinonasal sarcoma. There were 14 patients with rhabdomyosarcoma; 3 were cured with modern combined-modality therapy. Patients with positive surgical margins should be treated with adjuvant radiotherapy. Surgical therapy is effective for low-grade lesions that are completely excised.

The responses of neurons in subdivisions of the inferior colliculus of cats to tonal, noise and vocal stimuli

The aim of this study was to gain information from anesthetized cats about the differential coding properties of neurons in the three major subdivisions of the inferior colliculus: the central (CNIC) and external (EN) nuclei and dorsal cortex (DC). Stimuli were presented in the free field from a speaker facing the contralateral pinna. For each unit, the characteristic frequency (CF, where threshold was lowest) was determined, and impulse rates to CF tone bursts, noise bursts and four feline vocal stimuli were measured as a function of increasing sound pressure level (rate/level functions). Peristimulus-time histograms were computed for responses to all stimuli. Sustained firing patterns to CF stimuli were observed for 81% of units in CNIC, for 50% of units in EN and 27% of units in DC. Sustained discharges were evoked by noise in 78-100% of units in all regions, and by at least one vocal stimulus in 86% of units in CNIC, 82% in EN and 55% in DC. In the CNIC, non-monotonic rate/level functions to CF stimuli were more common (41%) than either monotonic or plateau functions, whereas the reverse was the case with noise and vocal stimuli. Non-monotonic functions were uncommon to any stimulus in EN and DC (21-24%). Vocal stimuli were more effective in terms of higher firing rates than noise or CF stimuli in 27% of units in CNIC, 82% in EN and 72% in DC. There were no units that responded exclusively to one vocal stimulus, but a high proportion of units in EN responded strongly to broad band stimuli, and some of these showed clear preferences for one vocal stimulus over others.

Accumulation of the F plasmid TraJ protein in cpx mutants of Escherichia coli

We report here studies of the cellular control of F plasmid TraJ protein levels, focusing on the effects of chromosomal cpx mutations. The principal conclusion from our results is that the cpx mutations impair accumulation of the TraJ protein, thereby reducing tra gene expression. We measured TraJ activity in vivo by expression of a traY'-'lacZ fusion gene and TraJ protein by immuno-overlay blot. In strains with normal TraJ levels, traY expression and donor-related functions were reduced in cells carrying any of four cpxA mutations. In the strain background used to isolate cpx mutants, these reductions were especially evident in cells grown to high density, when traY expression and donor activity both increased in cpx+ cells. In each of the four cpxA mutants tested, TraJ levels were lower than in the otherwise isogenic cpxA+ strain. In cells grown to high density, the differences ranged from 4-fold in the cpxA6 strain to > 10-fold in the cpxA2, cpxA5, and cpxA9 strains. The cpxA2 mutation had little or no effect on traY expression or on donor-related functions when TraJ was present in excess of its limiting level in F' or Hfr cells or on a mutant traY promoter whose expression in vivo was independent of TraJ.

Lymphatic drainage of hypertonic solution from peritoneal cavity of anesthetized and conscious sheep

Lymphatic drainage of the peritoneal cavity may reduce ultrafiltration in continuous ambulatory peritoneal dialysis. We assessed lymphatic drainage of the peritoneal cavity in sheep under dialysis conditions by cannulation of the relevant lymphatic vessels and compared lymphatic drainage in anesthetized and conscious animals. Lymph was collected from the caudal mediastinal lymph node and the thoracic duct, both of which are involved in the lymphatic drainage of the ovine peritoneal cavity. Volumes of a hypertonic dialysis solution (50 ml/kg 4.25% Dianeal) containing 25 microCi 125I-human serum albumin were instilled into the peritoneal cavity, and lymph flows and the appearance of labeled protein in the lymphatic and vascular compartments were monitored for 6 h. Intraperitoneal pressures increased 4-5 cmH2O above resting levels after infusion of dialysate. On the basis of the appearance of tracer in the lymph, drainage of peritoneal fluid into the caudal lymphatic was calculated to be 3.09 +/- 0.69 and 14.14 +/- 2.86 ml/h in anesthetized and conscious sheep, respectively. Drainage of peritoneal fluid into the thoracic duct preparations was calculated to be 1.32 +/- 0.33 and 14.69 +/- 5.73 ml/h in anesthetized and conscious sheep, respectively. Significant radioactivity was found in the bloodstream, and at least a portion of this was likely contributed by the right lymph duct, which was not cannulated in our experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraperitoneal carboplatin in advanced ovarian carcinoma

24 patients with advanced epithelial ovarian cancer, who demonstrated a clinical complete or partial response to the induction of intravenous chemotherapy, underwent implantation of a subcutaneous semipermanent port-and-catheter system (Port-A-Cath) for intraperitoneal chemotherapy, which consisted of carboplatin 300 mg/m2 every 4 weeks. The median survival was 27.4 months for minimal residual disease versus 8 months for bulky disease (p = 0.0054). The median progression-free interval was 15.7 months for minimal residual disease versus 1.8 months for bulky disease (p = 0.008). There were 3 complications (12.5%) related to the catheter: 1 perforation of the large bowel and 2 catheter inflow obstructions. Myelosuppression, especially a grade 3 leucopenia in 5 patients (25%) and a grade 4 thrombopenia in 3 patients (15%), was the dose-limiting toxicity. Even with maximum cytoreductive surgery and second-line intraperitoneal carboplatin-based chemotherapy, the 5-year progression-free survival (4.1%) remains very small.

Postoperative radiation therapy after radical prostatectomy for prostate carcinoma

BACKGROUND

The role and benefit of adjuvant radiation therapy after radical prostatectomy is unclear. This role was evaluated in 58 patients who, after undergoing radical prostatectomy for prostate carcinoma, had local extension of disease beyond the prostate or positive surgical margins. Thirty-nine patients treated surgically alone were compared with 19 patients who received adjuvant postoperative radiation therapy. All patients were followed for at least 5 years, and 50 patients had 10-year follow-ups.

RESULTS

At 10 years, the actuarial local failure rate was 31% for patients treated with prostatectomy alone versus 6% for the group receiving postoperative radiation therapy (P less than 0.05). The actuarial survival and metastasis-free survival were similar for both groups. When patients with involved lymph nodes were excluded from analysis, the addition of radiation therapy resulted in improved recurrence-free survival (91% versus 46% at 10 years, P = 0.04) and in a trend toward improved metastasis-free survival (91% versus 55%, P = 0.08). Complications occurred in similar frequencies in both groups.

CONCLUSIONS

In patients with local disease extension or positive surgical margins after radical prostatectomy, adjuvant radiation therapy improved local control and was administered with acceptable side effects.

Conservation therapy for invasive lobular carcinoma of the breast

Earlier literature suggests a high incidence of multicentricity and bilaterality, with an overall poor prognosis, in patients with invasive lobular carcinoma of the breast. Consequently, there is considerable disagreement regarding appropriate local management of this disease. To determine the influence of invasive lobular histologic findings on local tumor control, disease-free survival, and overall survival, the authors reviewed 60 patients with Stage I and II invasive lobular breast carcinoma treated with local tumor excision and radiation therapy between 1981 and 1987 (mean follow-up, 5.5 years; range, 2.5 to 10 years). The 5-year actuarial risk of locoregional recurrence was 5%, with two of three failures occurring in the regional lymphatics. The mean time to locoregional failure was 28 months. The 5-year actuarial disease-free survival (84%) and overall survival (91%) were comparable to those seen in several large series of similarly treated patients with invasive ductal carcinoma. Contralateral breast cancer occurred at a rate of approximately 0.6% per year. This study and a review of the literature suggest that breast conservation, with local resection and radiation therapy, is appropriate therapy for invasive lobular breast cancer.

Cloning and expression of a novel protease gene encoding an extracellular neutral protease from Bacillus subtilis

We have cloned from Bacillus subtilis a novel protease gene (nprB) encoding a neutral protease by using a shotgun cloning approach. The gene product was determined to have a molecular mass of 60 kDa. It has a typical signal peptide-like sequence at the N-terminal region. The expression of nprB can be stimulated by using a B. subtilis strain, WB30, carrying a sacU(h)h mutation. Expression of this protease gene results in production of a 37-kDa protease in the culture medium. The first five amino acid residues from the N terminus of the mature protease were determined to be Ala-Ala-Gly-Thr-Gly. This indicates that the protease is synthesized in a preproenzyme form. The purified protease has a pH optimum of around 6.6, and its activity can be inhibited by EDTA, 1,10-phenanthroline (a zinc-specific chelator), and dithiothreitol. It retained 65% of its activity after treatment at 65 degrees C for 20 min. Sequence comparison indicates that the mature form of this protease has 66% homology with the two thermostable neutral proteases from B. thermoproteolyticus and B. stearothermophilus. It also shares 65, 61, and 56% homology with the thermolabile neutral proteases from B. cereus, B. amyloliquefaciens, and B. subtilis, respectively. The zinc-binding site and the catalytic residues are all conserved among these proteases. Sequence homology extends into the "propeptide" region. The nprB gene was mapped between metC and glyB and was not required for growth or sporulation.

Engineering a Bacillus subtilis expression-secretion system with a strain deficient in six extracellular proteases

We describe the development of an expression-secretion system in Bacillus subtilis to improve the quality and quantity of the secreted foreign proteins. This system consists of a strain (WB600) deficient in six extracellular proteases and a set of sacB-based expression vectors. With the inactivation of all six chromosomal genes encoding neutral protease A, subtilisin, extracellular protease, metalloprotease, bacillopeptidase F, and neutral protease B, WB600 showed only 0.32% of the wild-type extracellular protease activity. No residual protease activity could be detected when WB600 was cultured in the presence of 2 mM phenylmethylsulfonyl fluoride. By using TEM beta-lactamase as a model, we showed that WB600 can significantly improve the stability of the secreted enzyme. To further increase the production level we constructed an expression cassette carrying sacY, a sacB-specific regulatory gene. This gene was placed under the control of a strong, constitutively expressed promoter, P43. With this cassette in the expression vector, an 18-fold enhancement in beta-lactamase production was observed. An artificial operon, P43-sacY-degQ, was also constructed. However, only a partial additive enhancement effect (24-fold enhancement) was observed. Although degQ can stimulate the production of beta-lactamase in the system, its ability to increase the residual extracellular protease activity from WB600 limits its application. The use of the P43-sacY cassette and WB600 would be a better combination for producing intact foreign proteins in high yield.

Osteogenic sarcoma of the head and neck. The UCLA experience

Eighteen cases of osteogenic sarcoma of the head and neck were treated at our institution between 1955 and 1987. The patients' ages ranged from 5 to 73 years, with a median age of 28 years. The sex distribution was equal. Follow-up ranged from 1 to 276 months, with a median of 79 months. The primary site of the tumor was the mandible in nine cases, maxilla and paranasal sinuses in six, skull in two, and orbit in one. Six of 18 patients were free of disease with greater than 5 years of follow-up. Four of the six received combined surgery, radiation therapy, and chemotherapy as their primary treatment. Of the five patients treated with surgery alone, four suffered recurrences, one of whom was salvaged with further surgery and chemotherapy. Five patients were treated initially without surgery. They received radiation therapy with or without chemotherapy; all five developed local recurrence. We conclude that osteogenic sarcoma of the head and neck is an aggressive tumor, prone to both local and distant failure. Based on our series and from published experience involving the extremities, osteogenic sarcoma of the head and neck should be managed with multimodality therapy.

Fibrosarcoma of the head and neck. The UCLA experience

Between 1955 and 1987, twenty-nine patients with the diagnosis of fibrosarcoma of the head and neck were seen at the UCLA Medical Center. Follow-up ranged from 15 to 192 months, with a median of 66 months. Absolute 5-year survival was 62% (13/21). Five of 17 patients treated initially with surgery alone achieved local control and long-term survival. All five had low-grade lesions. Five patients received postoperative radiation therapy because of positive surgical margins. Three were rendered disease free, and all had low-grade lesions. Radiation therapy was used as primary treatment in six patients, four of whom received additional chemotherapy. Of these six, two are disease free with longer than 5-year follow-up. Surgery with and without adjuvant therapy successfully salvaged 42% (5/12) of the patients with local recurrence. Eighty percent (12/15) of the patients with low-grade lesions were ultimately rendered disease free vs only 8% (1/12) of the patients with high-grade histologic features. Seventy-two percent (13/18) of the patients with local recurrence were known to have positive surgical margins. Sixty-eight percent (13/19) of the patients with recurrent disease had high-grade lesions and/or tumor size larger than 5 cm. Tumor grade is the most important prognostic factor followed by tumor size and surgical margin status. Patients with low-grade lesions and adequate surgical margins are treated well with surgery alone. Patients with high-grade lesions or positive surgical margins should receive adjuvant treatment.

Postoperative irradiation for the prevention of heterotopic bone: analysis of different dose schedules and shielding considerations

Ninety-seven high risk hips were irradiated postoperatively for prevention of heterotopic bone (HTB) in the UCLA Department of Radiation Oncology from 1980 to 1988. Ninety-two hips in 82 patients were eligible for analysis with a minimum follow-up of 2 months and a median follow-up of 10 months. Forty-nine of the hips had porous coated ingrowth prostheses. From 1980 to 1986, 2 Gy fractions were used to deliver 20 Gy (8 hips), 12 Gy (1 hip), and 10 Gy (27 hips). Since December of 1986, 38 hips received 8 Gy in two increments and 18 hips received a single 7 Gy fraction. All porous ingrowth components were shielded with custom blocks. Six out of 92 hips developed clinically significant (Brooker grade 3 or 4 heterotopic bone). There was one clinically significant failure in 78 hips (1.3%) when irradiation was initiated before post-operative day (POD) #6 and shielding was properly placed. One clinical failure occurred in 38 hips which received 8 Gy in two increments. One clinical failure occurred out of the 18 hips treated with 7 Gy in one fraction. This failure could be related to block malposition. There were four clinical failures in the 36 hips treated with 2 Gy fractions to total doses of 10 Gy, 12 Gy, or 20 Gy. Three of these failures were associated with initiation of treatment after POD #5, and the fourth was related to block malposition. Unshielded trochanteric osteotomies resulted in five migrations and seven fibrous unions for a total non-osseous union rate of 12/36 (33%). Shielding of the remaining 28 trochanteric osteotomies resulted in a non-osseous union rate of 7% (0 migrations and 2 fibrous unions). There were no failures of union of components, and the only side effects noted in the series were the five trochanteric migrations. In conclusion, the use of 8 Gy in two increments or 7 Gy in one fraction was found to be as efficacious as conventional 2 Gy fractionation schemes with no increase in side effects. For optimal results, treatment should be implemented prior to POD #5 with shielding of the trochanteric osteotomy. Postoperative irradiation to prevent HTB can be used in hips with porous components using properly placed blocks to shield the porous region.

Salivary gland tumors of the oral cavity

Between 1961 and 1985, 62 patients with malignant salivary gland tumors of the oral cavity underwent surgery with curative intent at the University of California, Los Angeles (UCLA) Medical center. All patients had a minimum follow-up of 2 years. Fifty of 62 (81%) patients presented with T1-2 primary tumors. The tumors arose from the palate in 41/62 (66%) patients. The most common histologic type was adenoid cystic carcinoma comprising 34 of 62 (55%) cases. Radical resection was performed in 46 cases and wide local excision in 16 patients. Postoperative radiation therapy was used in 24 cases due to advanced stage and/or positive surgical margins. Results of treatment were analyzed by stage of disease, modes of treatment, histology, and surgical extent. Local control of small lesions reached 100% at 10 years with either radical resection alone or local excision. With residual tumor at the surgical margins, the incidence of local recurrence was 4/14 (29%) for those who received adjuvant radiation therapy and 5/10 (50%) for those who did not. The vast majority of mucoepidermoid carcinomas were early stage and low grade. These lesions had an excellent prognosis with a control rate of 100%. In contrast, there was a 29% (10/34) failure rate for adenoid cystic carcinoma. The 5-, 10-, and 15-year actuarial survivals for the whole group were 94%, 84%, and 73%, respectively. Our results indicate that for early stage disease, wide local excision may offer patients the chance to avoid the cosmetically and functionally debilitating effects of radical surgery without compromising treatment outcome. Adjuvant radiation therapy appears to reduce the local recurrence for those with residual tumor at the surgical margins.

Malignant salivary gland tumors of the paranasal sinuses and nasal cavity. The UCLA experience

Between 1962 and 1985, 35 patients with malignant salivary gland tumors of the paranasal sinuses and nasal cavity were treated with curative intent at UCLA. They were staged according to the American Joint Committee (TNM) classification for squamous cell carcinoma of the paranasal sinuses: 27 of 35 (77%) patients presented with T3-4 disease. Adenoid cystic carcinoma was the diagnosis in 24 (68%) patients, while adenocarcinoma accounted for half of the cases involving the ethmoid sinuses and nasal cavity. Eleven patients were treated with surgery alone, 13 with combined surgery and radiation, and 11 with radiation therapy alone. All patients were followed from 40 to 216 months. Analysis by treatment modality revealed a local control of 18% (2 of 11) in the surgery alone group, 62% (8 of 13) in the combined group, and 9% (1 of 11) in the radiation alone group. The group undergoing combined treatment achieved the highest local control rate despite having a higher proportion of patients with advanced stage and residual disease at the surgical margins. In patients with positive surgical margins, the tumor recurred locally in 4 of 6 (67%) unirradiated patients, compared with 3 of 10 (30%) of those undergoing postoperative irradiation. Patients with adenoid cystic carcinoma had poorer results, with only 25% remaining relapse-free, compared with 45% of patients with adenocarcinoma. The 5-, 10-, 15-, and 20-year actuarial survival for all cases was 73%, 60%, 32%, and 20%, respectively. We conclude that post-operative radiation improves the results of treatment in all patients with malignant salivary gland tumors in this location, compared with the results of surgery alone.

Primary radiation therapy in the treatment of squamous cell carcinoma of the soft palate

From 1970 to 1986, 45 patients received primary radiation therapy for squamous cell carcinoma of the soft palate at the University of California Los Angeles (UCLA) Center for the Health Sciences and Wadsworth Veteran's Administration Hospital. Seven patients were lost to follow-up or had prior irradiation, and were excluded. Thirty-eight patients received a median dose of 70 Gy (62.5 to 80 Gy) to the primary site. After a median follow-up of 48 months, initial control of disease at the primary site was accomplished in 74% of the patients. The initial control by stage was as follows: TI, 83%, T2, 67%; and T3, 63%. After surgical salvage, local control increased to 92%, 80% and 75% for stages T1, T2, and T3, respectively. Twenty-nine percent (11 of 38) of the patients had cervical node metastases at presentation. Radiation provided regional control in 96% (26 of 27) with N0 disease and 86% (six of seven) with N1 disease at diagnosis. Sixteen patients (42%) had an additional malignancy of the upper aerodigestive tract. Because the incidence of second malignancies after treatment is high and surgical salvage of treatment failures is possible, close follow-up is essential in the management of this tumor. We conclude that radiation therapy is an effective modality for the treatment of squamous cell carcinoma of the soft palate. Primary radiation therapy may offer many patients the chance to avoid surgical procedures that are both cosmetically and functionally debilitating without compromosing treatment outcome.

Effect of experimental azotemia on intestinal transport of butyric acid

Earlier studies have revealed an impairment of jejunal absorption of long chain fatty acids in experimental uremia. We investigated the intestinal absorption of butyric acid which is a short chain fatty acid in experimental renal failure (RF). Sprague-Dawley rats were randomized into the RF group which had subtotal nephrectomy, a sham-operated control group, and a pair-fed group. In vivo recirculating perfusion (n = 5) and in vitro everted sac incubation (n = 8) were employed. The in vitro experiments were repeated substituting the serosal buffer by either predialysis or postdialysis sera from uremic individuals, or normal serum (n = 10). The rate of in vivo butyric acid absorption was significantly lower while the in vitro absorption was significantly higher in the RF group than those observed in the sham-operated and pair-fed groups which showed comparable values. The normality of butyric acid absorption in the pair-fed animals despite comparable weight loss with the RF group tends to exclude anorexia and weight loss as a cause of altered butyric acid transport in RF animals. The disparity between the in vivo and in vitro data is suggestive of an inhibitory influence of uremic environment which is present in vivo and absent in vitro. This viewpoint was corroborated by the observed fall in butyric acid absorption by sacs containing predialysis uremic serum as compared with those containing normal or postdialysis sera. The latter further suggests that the inhibitory factor(s) is dialyzable.

Salivary gland tumors of the palate: the UCLA experience

A retrospective review of 38 patients with salivary gland tumors of the palate treated between 1961 and 1984 is presented. The majority of tumors were identified at an early stage. Most (23 of 38 cases) originated over the hard palate. The most common histological type was adenoid cystic carcinoma (22 cases). Twenty-five patients were treated with surgery alone, of whom, three had wide local excision. Thirteen patients received postoperative radiation therapy in addition to surgery. The local control was comparable for surgery alone and combined therapy (88% and 85%, respectively) although the combined therapy group was biased by more advanced disease, inadequate margins, and/or poorly differentiated histologies. Mucoepidermoid lesions had an excellent prognosis with local control of 100%. In contrast, there was a 23% recurrence rate for adenoid cystic carcinoma. Regional neck node metastasis was noted in 2% of the patients. This experience indicates that radical resection of palate salivary gland malignancy with adequate margins results in excellent local control. Adjuvant radiation therapy is recommended in cases where there is a question of adequate margins and in advanced lesions of high grade tumors.

Endocrine and hemodynamic effects of antagonism of fentanyl-induced respiratory depression by nalbuphine

Endocrine and hemodynamic changes associated with the antagonism of fentanyl by nalbuphine have not been reported. Therefore, the authors studied ten patients after anesthetic induction with thiopental, fentanyl, tracheal intubation aided by succinylcholine and maintenance with diazepam, pancuronium, N2O, and further doses of fentanyl. Eight of the patients underwent cholecystectomy, one had a hysterectomy, and another had an abdominoplasty. After reversal of neuromuscular block at the conclusion of surgery, normal ventilation was restored by 0.22 +/- 0.02 mg/kg intravenous nalbuphine (mean +/- SEM). Plasma levels of free norepinephrine, histamine, and cortisol did not increase after antagonism of the fentanyl-induced respiratory depression, but plasma concentration of epinephrine increased significantly but without significant hemodynamic changes. Minute ventilation was 1.5 +/- 0.4 L/min before and 11 +/- 1, 10 +/- 1, 11 +/- 1, and 10 +/- 1 L/min at 15, 30, 45, and 60 min after antagonism; corresponding PaCO2 levels were 56 +/- 2, 44 +/- 1, 49 +/- 7, 49 +/- 1, 42 +/- 1 mm Hg. The mean analogue pain score remained below 1.5. We conclude that nalbuphine effectively antagonizes fentanyl-induced respiratory depression without adverse endocrine and circulatory changes or loss of analgesia.

Major salivary gland tumors: treatment results and prognostic factors

A retrospective review of 133 patients with major salivary gland carcinomas treated between 1955 and 1981 is presented. The majority of cases (104) originated in the parotid gland. The most common histological type was mucoepidermoid carcinoma (39 cases). Tumor-free interval was longest for patients with acinic cell and mucoepidermoid carcinomas. In contrast, adenoid cystic carcinoma was poorly controlled, regardless of the form of treatment. Initial control of primary major salivary gland tumors was inversely related to the presence of disease at the surgical margins. In cases with microscopic or gross disease at the surgical margins, postoperative radiation therapy controlled the tumor locally in 18 of 26 patients (69%). Postoperative radiation therapy was generally used only in cases with high-grade histologies, advanced stages, or positive surgical margins. Of the patients treated with surgery alone, 53% achieved local control, as compared to 75% of the group which received postoperative radiation therapy. Although the difference was not statistically significant, we would have expected the combined therapy group to have a lower control rate due to more advanced disease. There was a low salvage rate (22%) and a high incidence of distant metastasis (60%) in recurrent cases. The data indicates that complete surgical resection results in the best local control, with or without adjuvant radiation. When the surgical margin is inadequate and re-excision not possible, adjuvant radiation therapy appears to have a role to optimize local control and survival.

Value of radiation therapy in addition to surgery for cancer of the head and neck

This historically controlled study evaluates radiation therapy in 119 patients--with squamous cell carcinomas of the head and neck--who underwent surgery alone (SA) or surgery plus radiation (S + R). The primary tumor control and nodal control, in patients with negative surgical margins who had surgery alone (SA), were 63% in the oral cavity, 60% in the oropharynx, and 67% in the hypopharynx. The same rates for S + R group and negative surgical margins were 100%, 73%, and 100%. Combining the patients with negative and positive surgical margins, control of the tumor and nodal control were the same in the oral cavity for both treatment groups (41% for SA and 44% for S + R) and increased with the addition of radiation in the oropharynx (30% for SA to 65% for S + R) and hypopharynx (33% for SA to 86% for S + R), in spite of higher percentages of T3 and T4 tumor and positive lymph nodes in the S + R group. The lower control rate in patients who had surgery alone could be due (in part) to inadequate surgery at the primary site (42% local excision) and lack of neck dissection (35% for SA vs. 77% for S + R). Postoperative radiation therapy to the primary site and neck is shown to effectively reduce local recurrence in patients with oral cavity and oropharynx cancer, regardless of surgical margins.

Concentrations of high-mobility-group proteins in the nucleus and cytoplasm of several rat tissues

Nuclear and cytoplasmic fractions were isolated from various tissues of the rat by a nonaqueous technique. The high-mobility-group (HMG) proteins were extracted from these fractions with acid and separated by one- and two-dimensional PAGE. The concentrations of high-mobility-group proteins HMG1, HMG2, and HMG17 in the nucleus and cytoplasm were then estimated from the staining intensities of the electrophoretic bands. The cytoplasmic concentrations of these proteins were very low--usually less than 1/30 of those present in the corresponding nuclear fractions. For the tissues studied (liver, kidney, heart, and lung), the concentrations of HMG proteins in the nucleus did not differ significantly from one tissue to another. Averaged over the four tissues investigated, there were 0.28 molecule of HMG1, 0.18 molecule of HMG2, and 0.46 molecule of HMG17 per nucleosome. These values are considerably higher than those that have been reported previously.