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.