Altered expression of cardiac myosin isozymes associated with the malignant hyperthermia genotype in swine

BACKGROUND

Anesthetic-induced malignant hyperthermia (MH) in humans and pigs is associated with dramatic alterations in cardiac function. However, it remains controversial as to whether MH-associated cardiac symptoms represent a primary difference of myocardium or a secondary alteration consequent to increases in the hyperthermic stress. Here the authors describe changes in myosin isoform expression in the hearts of MH-susceptible pigs with and without prior exposure to halothane.

METHODS

One group of pigs was diagnosed as MH susceptible by halothane challenge and Hal-1843 nucleotide examination. To determine if there is an effect of halothane exposure, another group of pigs was diagnosed by simple MH genotyping without exposure to halothane. After diagnosis and genotyping, animals with and without exposure to halothane were killed to study cardiac myosin isozyme distributions, cardiac myofibrillar adenosine triphosphatase (ATPase) activity, and the steepness of the Ca2+-ATPase activity relation in the hearts of normal and susceptible pigs. The altered myosin isozyme expression was analyzed by pyrophosphate gel electrophoresis.

RESULTS

Malignant hyperthermia-susceptible animals with the prior halothane challenge showed an increased V1 myosin (-44%) expression, increased myofibrillar ATPase activity (-25%) and increased steepness of the Ca2+-ATPase activity relation. Without exposure to halothane, no change of myofibrillar ATPase activity was found in the hearts of different genotyped pigs, but there was a small increase in expression of V1 myosin (-5%) in the mutant (TT).

CONCLUSIONS

The potential modulation of V1 myosin expression occurs in the hearts of MH-susceptible pigs. The added stress by halothane challenge would further cause a V3 --> V1 shift, which may be attributed to the long-term effects of hyperthermic stress.

cAMP attenuates interleukin-1-stimulated macrophage colony-stimulating factor (M-CSF) expression

Macrophage colony-stimulating factor (M-CSF) is a multifunctional cytokine attributed with key biological functions beyond the first discovered role in promoting proliferation of myeloid cell lineage. The human pancreatic cancer cell line MIA PaCa-2, from which the M-CSF gene was originally cloned, was used to study regulation of M-CSF expression. Expression of M-CSF was inducible by interleukin-1alpha (IL-1alpha), lipopolysaccharide (LPS) and PMA as demonstrated by a biological activity assay, Northern-blot analysis and reverse transcriptase (RT) PCR. Treatment of the cells with forskolin or dibutyryl-cAMP attenuated the expression of M-CSF induced by IL-1alpha or LPS, but not by PMA. Electromobility shift assays showed that IL-1alpha predominantly activated nuclear factor kappaB (NF-kappaB), while PMA preferentially activated activator protein-1 (AP-1). The activation of NF-kappaB, but not AP-1, could be attenuated by cAMP elevation. Relative RT-PCR demonstrated that the expression of a 1.6-kb M-CSF mRNA transcript was more effectively induced by IL-1alpha than a 4.0-kb transcript. By and large the induced expression of both mRNA transcripts could be attenuated by cAMP. M-CSF promoter-driven luciferase reporter-gene assays revealed that cAMP elevation attenuated the IL-1-induced transcription activation of the M-CSF promoter, but it had no effect on PMA-induced transcription. Our findings suggest that cAMP regulates M-CSF gene expression at the transcriptional level and that its inhibitory effect involves NF-kappaB signalling pathway.

Expression of steroidogenic enzyme messenger ribonucleic acid and cortisol production in adrenocortical cells isolated from halothane-sensitive and halothane-resistant pigs

Stress susceptibility in pigs is inherited by a single recessive gene (Hal(n)), and homozygous individuals can be identified by exposure to halothane anesthesia. Previous studies have shown that in stress-susceptible pigs, exposure to a high ambient temperature resulted in a twofold increase in corticotropin (ACTH) and lower plasma cortisol. To determine whether there is a fundamental difference in adrenocortical function between halothane-sensitive (HAL-S) and halothane-resistant (HAL-R) pigs, independent of other factors influencing the hypothalamic-pituitary-adrenal (HPA) axis, we compared cortisol responses to ACTH and 8-bromo-cyclic AMP (8-Br-cAMP) in HAL-S and HAL-R pig adrenocortical cells in vitro. We also determined directly the accumulation of four different mRNAs encoding cholesterol side-chain cleavage cytochrome P450 (P450(scc)), 17alpha-hydroxylase cytochrome P450 (P450(17alpha)), 21-hydroxylase cytochrome P450 (P450(c21)) and 11beta-hydroxylase cytochrome P450 (P450(11beta)) in HAL-S pig adrenal cells and compared them to HAL-R pigs. A time- and dose-dependent increase in medium content of cortisol and cAMP was observed after ACTH treatment. 8-Br-cAMP also caused a time- and dose-dependent increase in cortisol production in the medium. Addition of ACTH or 8-Br-cAMP to HAL-S and HAL-R male Lanyu small-ear miniature pig adrenocortical cells increased cortisol production in a dose- and time-related manner. However, cells isolated from HAL-S pigs had a lower cortisol production in response to ACTH or 8-Br-cAMP compared to those from HAL-R pigs. Treatment of cultured cells with 8-Br-cAMP (0.5 mM) for 18 h resulted in a significant increase in P450(scc), P450(17alpha), P450(c21), and P450(11beta) mRNA levels. In the absence of 8-Br-cAMP, the four genes were expressed constitutively in both HAL-S and HAL-R pig adrenal cells. Densitometric scanning of the autoradiograph indicated that the relative amounts of P450(scc) and P450(17(alpha)) mRNAs in HAL-S pig adrenal cells were between 48% and 53% of those detected in HAL-R pig adrenal cells (P < 0.05). No difference in the amounts of P450(c21) and P450(11beta) was seen in HAL-S and HAL-R pig adrenal cells. Addition of 8-Br-cAMP (0.5 mM) resulted in a uniform increase in the levels of all four P450 mRNAs in both HAL-S and HAL-R pig adrenal cells. However, the amounts of P450(scc) mRNA in HAL-S pig adrenal cells were 67% (P < 0.05) of those measured in HAL-R pig adrenal cells, whereas the amounts of P450(17alpha ), P450(c21), and P450(11beta) mRNAs were similar in these cells. Our data suggest an HPA axis defect in HAL-S pigs at the adrenal level. This defect appears to be at the level of P450scc gene expression, which could be partially related to reduced cortisol production by ACTH stimulation.

Carrier detection of Duchenne/Becker muscular dystrophy by using fluorescent linkage analysis in Taiwan

The mutation analysis of Duchenne/Becker muscular dystrophy (DMD/BMD) is made difficult by the size and structure of the gene. The dystrophin gene deletion is responsible for 45-58% of DMD/BMD cases in Taiwan. For the others, who have no deletions, carrier detection was performed by DNA linkage analysis. To determine frequencies of each allele and heterozygosity of each short tandem repeats (STR) marker, we analyzed 50 unrelated Taiwanese males and 50 unrelated Taiwanese females unaffected by DMD/BMD using ten fluorescently labeled intragenic markers (these ten being located in 5' terminus, intron 1, 44, 45, 48, 49, 50, 55-57 and 3' untranslated region of the human dystrophin gene). The predicted heterozygosity frequency is 46.7-88.3% in our study population and these STR markers are quite informative for linkage analysis. Using these ten intragenic STR markers, we analyzed 14 DMD/BMD families with 62 family members for carrier detection. Our retrospective study of DMD/BMD families highlights the informative power of STR haplotyping. In summary, STR analysis using (CA)n repeats within the human dystrophin gene is well suited for routine use in clinical laboratories engaged in linkage studies for carrier detection and prenatal diagnosis in DMD/BMD families.

Feasibility of a clinical trial of augmentation therapy for alpha(1)-antitrypsin deficiency. The Alpha 1-Antitrypsin Deficiency Registry Study Group

We examined the feasibility of a randomized clinical trial of intravenous augmentation therapy for individuals with alpha 1-antitrypsin (alpha1AT) deficiency, basing calculations on newly available data obtained from the NHLBI Registry of Patients with Severe Deficiency of Alpha 1-Antitrypsin. Using rate of FEV(1) decline as the primary outcome and adjusting for noncompliance, a study of subjects with Stage II chronic obstructive pulmonary disease (COPD) (initial FEV(1) 35 to 49% predicted) with biannual spirometry measures obtained over 4 yr of follow-up would require 147 subjects per treatment arm to detect a difference in FEV(1) decline of 23 ml/yr (i.e., a 28% reduction), the difference observed in the NHLBI Registry (1-sided test, alpha = 0.05, 90% power). To detect a 40% reduction in mortality in a 5-year study of subjects with baseline FEV(1) 35 to 49% predicted, recruited over the first 2 yr and then followed an additional 3 yr, 342 subjects per treatment arm would be needed. Though significant impediments to carrying out a clinical trial exist, including the cost of such a trial and the potential difficulties in recruiting patients for a placebo-controlled trial, we recommend a randomized controlled trial as the best method to evaluate the efficacy of intravenous augmentation therapy and of possible future treatments.

Epimeric separation of L-ascorbic acid and D-isoascorbic acid by capillary zone electrophoresis

Capillary zone electrophoresis (CZE) was used for separation of L-ascorbic acid (L-AA) and D-isoascorbic acid (D-IAA) in a model system. The effects of borate buffer concentration (0.05-0.25 M) and pH (pH 7.5-9.0) on migration time, resolution (Rs), and theoretical plates (N) were investigated. The migration times of L-AA and D-IAA increased with the increasing pH of carrier electrolyte (0.2 borate buffer), and the resolutions (Rs) of L-AA and D-IAA were calculated to be 12.98 at pH 9.0. Concentrations of borate buffer (pH 9.0) increased the Rs values of L-AA and D-IAA, and buffer concentrations >0.1 M were found to be effective for separation of L-AA and D-IAA. Methanol in the carrier electrolyte was also influential in improving the separation of L-AA and D-IAA, which increased with the increasing concentrations (0-10%) of methanol. The optimal separation conditions for L-AA and D-IAA were as follows: carrier electrolyte, 0.2 M borate buffer (pH 9.0); applied voltage, 25 kV, with an uncoated fused silica capillary, 75 microm (i.d.) x 57 cm.

[Determination of glucosinolates in rapeseed by reversed-phase ion-pair liquid chromatography]

This paper presents a method for the direct determination of intact glucosinolates in rapeseed by reversed-phase ion-pair liquid chromatography (RILC). The catechin, mercaptoethanol and phytic acid was adopted respectively in sample pretreatment to prevent indole glucosinolates being oxidized. Among them, the effect of mercaptoethanol was the most obvious. The effects of composition and concentration of the mobile phase, the pH of the mobile phase and the column temperature on the retention and the capacity factor of the glucosinolates were studied. The condition of this method by RILC has been set up: column, YWG-C18 H37(10 microns, 250 mm x 4 mm i.d.); mobile phase, 0.02 mol/L KH2PO4 buffer(pH 6) containing 4.5 mmol/L (C4H8)4NBr and CH3CN(90/10, V/V); flow rate, 1 mL/min; detector, UV-226 nm; column temperation, 30 degrees C. In this condition, six glucosinolates were separated completely. The relative correction factors were determined by using sinigrin or benzoic acid as the internal standard. The characteristics of glucosinolates in different kinds of Chinese rapeseed can be determined by this RILC method.

Chlorpromazine inhibits hepatocyte apoptosis caused by withdrawal of phenobarbital in mice

AIM

To study the inhibitory effect of chlorpromazine (Chl), verapamil, and aspirin on hepatocyte apoptosis induced by the cessation of phenobarbital (Phe) treatment in mice.

METHODS

Liver DNA content, ratio of liver weight/body weight, DNA fragmentation, DNA electrophoresis, the end-labeling test (TUNEL), and the morphologic changes of liver cells as indices of liver mass and hepatocyte apoptosis were applied to investigate (1) the kinetic process of hepatocyte proliferation induced by Phe 75 mg.kg-1 i.p. and the regression of hyperplastic liver caused by withdrawal of Phe in mice, (2) the effect of Chl 25 mg.kg-1, verapamil 50 mg.kg-1 or aspirin 60 mg.kg-1 i.p. on mouse hepatocyte apoptosis, and (3) the time course of effects of Chl on the regression of liver size and DNA fragmentation content after withdrawal of Phe.

RESULTS

The process of hepatocyte proliferation and regression induced by administration and withdrawal of Phe in mice consisted of 4 phases: proliferation, plateau, rapid regression, and slow regression phases. In the rapid regression phase, the typic changes of hepatocyte apoptosis were found, which was prevented in early period by the Ca(2+)-calmodulin antagonist Chl, but not by verapamil or aspirin.

CONCLUSION

The Ca(2+)-calmodulin played an important role in the hepatocyte apoptosis caused by withdrawal of Phe.

Genetic characterization of the hemagglutinin of two strains of influenza B virus co-circulated in Taiwan

Two isolates of influenza B virus were obtained in the spring of 1997. One strain, B/Taiwan/21706/97, was isolated from a patient who had acute tonsillitis. The other, B/Taiwan/3143/97, was isolated from a patient who was diagnosed with meningoencephalitis. This implies that the influenza B viruses not only cause respiratory symptoms but may also cause inflammation of the nervous system. Sequence analysis of the hemagglutinin (HA) gene, HA1 domain, indicated that there were remarkable amino acid changes in the strain B/Taiwan/3143/97 compared to B/Victoria/2/87, B/Yamagata/16/88, and B/Taiwan/7/88. The changes in the positions 116, 200, 238, 242, and 271 were correlated with receptor binding. Furthermore, a potential glycosylation site at position 233 was lost. In total, 30 amino acid changes were noted at positions ranging from 116 to 295. These changes may affect the antigenicity of the virus. Phylogenetic analyses also showed that the B/Taiwan/3143/97 was located in an independent lineage, when compared to the reference strains belonging to B/Victoria/2/87 and B/Yamagata/16/88 lineages. This supports the hypothesis that influenza B viruses with distinct genetic characteristic were co-circulated in Taiwan.

The effects of bile duct obstruction on the biliary secretion of ciprofloxacin in piglets

OBJECTIVE

The aim of this study was to evaluate the effect of bile duct obstruction on biliary secretion of ciprofloxacin and to look for useful parameters to guide clinical use of antibiotics in patients with acute cholangitis.

METHODS

Twenty-five Landrace piglets were used in this study. Their common bile ducts were ligated, with a duration ranging from 1 to 7 days. The changes of liver biochemical tests, intrabiliary pressure, diameter of common bile duct, and concentration of ciprofloxacin in bile were compared among the piglets with different severity of bile duct obstruction.

RESULTS

The bile-to-serum ratio of the ciprofloxacin concentration was 586.4% +/- 140.3% before the ligation of bile duct and was reduced significantly to 94.5% +/- 118.0% after 1-day obstruction. The biliary secretion of ciprofloxacin was greatly affected by the intrabiliary pressure in that the bile-to-serum ratio of ciprofloxacin concentration was reduced to 12.2% +/- 14.8% when the intrabiliary pressure reached to 32 cm H2O. The change in the intrabiliary pressure was correlated with the diameter of common bile duct, with a correlation coefficient of 0.90 (p < 0.001).

CONCLUSIONS

Biliary secretion of ciprofloxacin is decreased in proportion to the increase of intrabiliary pressure. In obstruction, a markedly dilated common bile duct usually indicates high intrabiliary pressure, and thus biliary concentrations of antibiotics will be lower than expected. Hence, our observations suggest that choosing an antibiotic with high antimicrobial activity, or establishing a biliary drainage to lower the intrabiliary pressure, would be beneficial for patients suffering from cholangitis with a dilated biliary tree.

Effectiveness of psoralen photochemotherapy for vitiligo

To evaluate the response to oral psoralen ultraviolet-A (PUVA) photochemotherapy in patients with vitiligo in Taiwan, we retrospectively reviewed the clinical data of 21 vitiligo patients treated from 1990 to 1998. Diagnosis included generalized vitiligo in 16 patients, focal vitiligo in three, and acrofacial vitiligo in two. All patients were treated two to three times per week over a period of 3 to 19 months with 0.2 to 0.4 mg/kg of trioxsalen 2 hours before exposure to long-wave ultraviolet light irradiation. The results for PUVA therapy showed 10 patients (48%) had an excellent response (75-100% repigmentation), four (19%) had a good response (50-75% repigmentation), one had a moderate response (25-50% repigmentation), and six (29%) had a poor response (0-25% repigmentation). Despite the high rate of satisfactory outcomes, the response to PUVA therapy with respect to specific localization revealed poor response in eight out of 10 patients with vitiligo on the hands and feet. Acute adverse effects of PUVA included pruritus in eight patients xerosis in one patient, and burning with blistering in four patients. Long-term adverse effects such as actinic keratosis and skin cancer were not found within the follow-up period, which ranged from 2 months to 7 years. Our findings indicate that long-term oral PUVA with trioxsalen is an effective treatment for vitiligo in Taiwanese patients.

Use of summary measures to adjust for informative missingness in repeated measures data with random effects

We discuss how to apply the conditional informative missing model of Wu and Bailey (1989, Biometrics 45, 939-955) to the setting where the probability of missing a visit depends on the random effects of the primary response in a time-dependent fashion. This includes the case where the probability of missing a visit depends on the true value of the primary response. Summary measures for missingness that are weighted sums of the indicators of missed visits are derived for these situations. These summary measures are then incorporated as covariates in a random effects model for the primary response. This approach is illustrated by analyzing data collected from a trial of heroin addicts where missed visits are informative about drug test results. Simulations of realistic experiments indicate that these time-dependent summary measures also work well under a variety of informative censoring models. These summary measures can achieve large reductions in estimation bias and mean squared errors relative to those obtained by using other summary measures.

Technetium-99m-HmPAO brain SPECT in infantile Gaucher's disease

The authors report serial technetium-99m hexamethylpropylene-amine-oxime brain single photon emission computed tomography (SPECT) findings in two infants with Gaucher's disease type 2. Detailed neurologic and laboratory examinations, including bone marrow biopsies and enzymatic assays, were described. Serial brain magnetic resonance imaging studies in one patient illustrated the progressive cerebral atrophy in the frontal and temporal lobes. The SPECT in both cases demonstrated positive findings of initial scattered hypoperfusion, with extending to hypoperfusion of the entire cerebrum after 4 months of clinical deterioration. These changes in the SPECT findings may reflect progressive degeneration of the cerebrum in Gaucher's disease type 2. Brain SPECT may provide useful information on cerebral flow and metabolic distribution corresponding to the neurologic deficits of neuronopathic Gaucher's disease.

The radiation induced magnetic resonance image intensity change provides a more efficient three-dimensional dose measurement in MRI-Fricke-agarose gel dosimetry

A detailed methodology has been developed to map the spatial dose distribution in a Fricke-agarose gel based on the radiation induced image intensity change in the gel's magnetic resonance (MR) images. Besides the linear correlation between the change in the gel's spin-lattice relaxation rate and the absorbed dose, it is shown here that the radiation induced image intensity change for T1-weighted spin-echo images with TE << TR correlates exponentially to the absorbed dose. Furthermore, at the lower dose region (< 15 Gy), the correlation is fairly linear and its sensitivity is high. The minimum detectable dose is shown to be equivalent to the one obtained using the conventional R1-based approach. Since only one T1-weighted image is required for the dose evaluation, compared to the R1-based method, the total MR imaging time can be reduced from hours to a few minutes. This extensive time reduction avoids ferric ion diffusion effects and provides a practical way to simply and effectively measure the three-dimensional dose distribution using the Fricke-agarose dosimeter gel.

Induction of hepatocyte proliferation and prevention of hepatocyte apoptosis by phenobarbital related to local humoral factor in mouse liver

AIM

To study the association of phenobarbital (Phe) inducing hepatocyte proliferation and blocking hepatocyte apoptosis with local humoral factor in liver.

METHODS

The ratio of liver/body weight, DNA content, regressive rate of hyperplastic liver, and DNA fragmentation were used to investigate whether the Phe-treated mouse liver extract (PMLE) and PMLE-95 (PMLE heated at 95 degrees C for 30 min) possessed Phe-like effects on mouse liver. Meantime, the effects of pretreatment with trypsin, RNAase, and DNAase on the activity of PMLE-95 were observed, and the differences of components between PMLE-95 and NMLE-95 (normal mouse liver extract, NMLE heated at 95 degrees C for 30 min) were analyzed with HPLC.

RESULTS

PMLE-95 stimulated hepatocyte proliferation and prevented hepatocyte apoptosis caused by withdrawing Phe in mice, and the activity of PMLE-95 was eliminated after the pretreatment with trypsin. On the chromatograms PMLE-95 had 5 main peaks, while NMLE-95 had only 4 peaks.

CONCLUSION

The effects of Phe on the liver were mediated by an intrinsic protein or peptide substance produced in response for the stimulation of Phe in mouse liver.

Glial cell line-derived neurotrophic factor protects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity in C57BL/6 mice

To mimic chronic exposure to neurotoxins in inducing dopaminergic cell damage, multiple doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were injected in C57BL/6 mice. Effects of pre- and post-treatment with the glial cell line-derived neurotrophic factor (GDNF) by injections into the striatum were investigated. GDNF exerts protective and reverse effects on the dopaminergic damage, supporting the potential application of GDNF in prevention and treatment of Parkinson's disease.

Cerebral perfusion in children with Alice in Wonderland syndrome

Alice in Wonderland syndrome (AIWS) is characterized by visual hallucinations and bizarre perceptual distortions. Technetium-99m hexamethylpropyleneamine tomography (SPECT) brain scans were performed in four patients during the acute stage of AIWS. Two patients were demonstrated to have Epstein-Barr virus infections. One had abnormal (EEG) findings. The visual-evoked potential, cranial CT, and MRI findings were negative. The decreased cerebral perfusion areas in all patients were near the visual tract and visual cortex. All involved some regions of the temporal lobe. In most patients with AIWS, the EEG, CT, and MRI are unable to determine the precise pathologic areas. However, a SPECT brain scan may demonstrate abnormal perfusion areas and explain the clinical presentations.

Decreased expression of the adenomatous polyposis coli (Apc) and mutated in colorectal cancer (Mcc) genes in mouse lung neoplasia

A decrease in the intracellular concentrations of the transcripts for some tumor suppressor genes has been found during murine lung tumorigenesis; for p15INK4b and p16INK4a, this was due to homozygous deletions. We report here a decrease in the mRNA levels of the mutated in colorectal cancer (Mcc) and adenomatous polyposis coli (Apc) genes in mouse lung tumors and some neoplastic cell lines. This was assessed both by northern blotting and reverse transcriptase-polymerase chain reaction of RNA isolated from lung tumors that had been induced by urethane, N-nitrosodiethylamine, or 3-methylcholanthrene in (A/J x C57BL/6) F1 or A/J mice. A reduced amount of both Mcc and Apc messages was also seen when two neoplastic cell lines, a spontaneous transformant (E9) and a line derived from a chemically induced solid tumor (82-132), were compared with two independently derived nontumorigenic cell lines (E10 and C10); E9 was derived from E10, and all of these lines are probably of alveolar type 2 cell origin. A cell line derived from a chemically induced papillary lung tumor probably of bronchiolar Clara cell origin (LM2) had Mcc mRNA levels similar to those of C10 and E10 but reduced Apc mRNA levels. A line (p53-823) derived from a papillary tumor that arose in a mouse with a mutated p53 transgene had a reduced amount of the Mcc gene product only. These differential changes in the relative amounts of Apc and Mcc messages in LM2 and p53-823) cells may serve as useful models for studying the regulation of their expression. Both messages had half-lives of 6-9 h in normal E10 and neoplastic E9 cells, so decreased message stability does not account for these reductions. This is the first report of estimated degradation rates of these mRNAs. Apc and Mcc message content did not vary as a function of growth status of the cell lines. Single-strand conformation polymorphism analysis did not reveal mutations in Apc coding regions known to have a high mutation frequency in human colon tumors. Loss of heterozygosity of Apc and Mcc was not found in tumors that developed in the F1 mice, implying a lack of allelic deletions. These changes in tumor suppressor gene expression may contribute to the development and maintenance of neoplasia in lung epithelium.

Genome wide search for genetic damage in p53 transgenic mouse lung tumours reveals consistent loss of chromosome 4

The tumour which develops most frequently in mice carrying a p53 Val135 transgene is adenocarcinoma of the lung. We established 10 cell lines from these tumours and investigated their karyotypes by detailed cytogenetic analysis using a complete set of mouse chromosome-specific paints. Consistent loss of chromosome 4 material was noted in 9 out of 10 cell lines; this loss was detected in tetraploid but not diploid cells of the same cell line, suggesting that mouse chromosome 4 plays a critical role in the progression of lung adenocarcinomas. Other frequently observed chromosome aberrations involved chromosomes 7, 5 and 8. Atypical bronchial epithelium was observed together with lung tumours and in tumour-free, apparently normal lungs indicating that mouse lung tumours induced due to the presence of a mutant p53 transgene may develop via pre-invasive lesions and thus may be effective models for the study of lung tumour progression.

Effective tumor vaccines generated by in vitro modification of tumor cells with cytokines and bispecific monoclonal antibodies

Antitumor immune responses are mediated primarily by T cells. Downregulation of the major histocompatibility complex (MHC) and the molecules that costimulate the immune response is associated with defective signaling by tumor cells for T-cell activation. In vitro treatment with a combination of cytokines significantly increased the expression of MHC class I and adhesion molecules on tumor cell surfaces. When tumor cells were first incubated with a bispecific monoclonal antibody that binds antigen on tumor cells to CD28 on T cells, the modified tumor cells become immunogenic and are able to stimulate naive T cells, generating tumor-specific cytotoxic T cells in vitro. Immunization with the modified tumor cells elicits an immune response mediated by CD8+ T cells. This response protected against a challenge with parental tumor cells and cured established tumors. The approach was effective in both low immunogenic and nonimmunogenic tumor model systems. Modification of tumor cells with this two-step procedure may provide a strategy for development of tumor vaccines that is effective for cancer immunotherapy.

Atrophic pigmented dermatofibrosarcoma presenting as infraorbital hyperpigmentation

BACKGROUND

Pigmented dermatofibrosarcoma is a rare tumor of the skin and constitutes 1-5% of all dermatofibrosarcoma. Most cases present as polypoid multinodular growth. Occasional cases may be atrophic. We report an extraordinary case with progressive infraorbital atrophy.

OBSERVATION

A 24-year-old woman came to us for a diffuse bluish atrophic lesion over the left infraorbital area. The lesion progressed gradually over 2 years. Histologic examination revealed mature spindle cell proliferation in the lower dermis and hypodermis. Interspersed were some heavily pigmented melanocytes.

CONCLUSION

We report an unusual case of progressive bluish discoloration and atrophy of the infraorbital area. This is a rare manifestation of dermatofibrosarcoma.

Operational design and quality control in the CATCH multicenter Trial

BACKGROUND

The Child and Adolescent Trial for Cardiovascular Health (CATCH) was the first multicenter school-based research study to employ the fundamentals of clinical trials including the standardized protocol and Manuals of Operation, a steering committee for study governance, a distributed data system, an extensive quality control system, and a Data and Safety Monitoring Board.

METHOD

CATCH tested the effectiveness of changes in school lunches, physical education, smoking policy, curricula, and family activities. Ninety-six elementary schools in four states were randomized to intervention or control conditions. The baseline cohort comprised 5, 106 ethnically diverse third graders followed through fifth grade.

RESULTS

The percentages of calories from fat and saturated fat were reduced significantly more in the intervention school lunches than among the controls. Significant increases in moderate to vigorous activity levels in existing physical education classes were made as well. Changes in self-reported dietary, physical activity, and psychosocial measures were significant. There were no significant differences in the physiological measures. Measurement error was generally low for all physiologic measures except skinfolds, indicating a high level of reliability. Across all sites, the coefficients of variation for lipids, height, and weight were less than 3%, whereas for skinfolds, they were considerably higher, ranging from 6 to 8%. Intraclass correlations for lipid studies were also uniformly high at 0.99. Interobserver agreement scores for SOFIT were greater than 90% for 9 of the 11 activities observed. Data entry error rates were low with less than five errors per 1,000 fields for all forms.

CONCLUSIONS

The CATCH results provided more scientific evidence on the importance of schools in the population approach to health promotion. Many of the strategies used in this complex multicenter trial in the areas of design and analysis, measurement, training, data management, and quality control protocols might be appropriate for adoption in other studies.

Realization of novel monolithic free-space optical disk pickup heads by surface micromachining

A novel monolithic free-space optical disk pickup head has been fabricated by micromachined micro-optical bench technology. The pickup head contains a self-aligned semiconductor edge-emitting laser, a collimating lens, a beam splitter, two focusing lenses, and two 45 degrees mirrors. All optical components are built monolithically on Si substrates. The 45 degrees mirror directs the optical output beam in the surface-normal direction. This novel design could signif icantly reduce the size and the weight of the optical pickup head as well as the cost of the assembly processes. The weight reduction could also greatly increase the data access rate.