Isobutanol Production by Autotrophic Acetogenic Bacteria

Two different isobutanol synthesis pathways were cloned into and expressed in the two model acetogenic bacteria Acetobacterium woodii and Clostridium ljungdahlii. A. woodii is specialized on using CO₂ + H₂ gas mixtures for growth and depends on sodium ions for ATP generation by a respective ATPase and Rnf system. On the other hand, C. ljungdahlii grows well on syngas (CO + H₂ + CO₂ mixture) and depends on protons for energy conservation. The first pathway consisted of ketoisovalerate ferredoxin oxidoreductase (Kor) from Clostridium thermocellum and bifunctional aldehyde/alcohol dehydrogenase (AdhE2) from C. acetobutylicum. Three different kor gene clusters are annotated in C. thermocellum and were all tested. Only in recombinant A. woodii strains, traces of isobutanol could be detected. Additional feeding of ketoisovalerate increased isobutanol production to 2.9 mM under heterotrophic conditions using kor3 and to 1.8 mM under autotrophic conditions using kor2. In C. ljungdahlii, isobutanol could only be detected upon additional ketoisovalerate feeding under autotrophic conditions. kor3 proved to be the best suited gene cluster. The second pathway consisted of ketoisovalerate decarboxylase from Lactococcus lactis and alcohol dehydrogenase from Corynebacterium glutamicum. For increasing the carbon flux to ketoisovalerate, genes encoding ketol-acid reductoisomerase, dihydroxy-acid dehydratase, and acetolactate synthase from C. ljungdahlii were subcloned downstream of adhA. Under heterotrophic conditions, A. woodii produced 0.2 mM isobutanol and 0.4 mM upon additional ketoisovalerate feeding. Under autotrophic conditions, no isobutanol formation could be detected. Only upon additional ketoisovalerate feeding, recombinant A. woodii produced 1.5 mM isobutanol. With C. ljungdahlii, no isobutanol was formed under heterotrophic conditions and only 0.1 mM under autotrophic conditions. Additional feeding of ketoisovalerate increased these values to 1.5 mM and 0.6 mM, respectively. A further increase to 2.4 mM and 1 mM, respectively, could be achieved upon inactivation of the ilvE gene in the recombinant C. ljungdahlii strain. Engineering the coenzyme specificity of IlvC of C. ljungdahlii from NADPH to NADH did not result in improved isobutanol production.

Identifying and Engineering Bottlenecks of Autotrophic Isobutanol Formation in Recombinant C. ljungdahlii by Systemic Analysis

Clostridium ljungdahlii (C. ljungdahlii, CLJU) is natively endowed producing acetic acid, 2,3-butandiol, and ethanol consuming gas mixtures of CO2, CO, and H2 (syngas). Here, we present the syngas-based isobutanol formation using C. ljungdahlii harboring the recombinant amplification of the "Ehrlich" pathway that converts intracellular KIV to isobutanol. Autotrophic isobutanol production was studied analyzing two different strains in 3-L gassed and stirred bioreactors. Physiological characterization was thoroughly applied together with metabolic profiling and flux balance analysis. Thereof, KIV and pyruvate supply were identified as key "bottlenecking" precursors limiting preliminary isobutanol formation in CLJU[KAIA] to 0.02 g L-1. Additional blocking of valine synthesis in CLJU[KAIA]:ilvE increased isobutanol production by factor 6.5 finally reaching 0.13 g L-1. Future metabolic engineering should focus on debottlenecking NADPH availability, whereas NADH supply is already equilibrated in the current generation of strains.

Electron availability in CO2 , CO and H2 mixtures constrains flux distribution, energy management and product formation in Clostridium ljungdahlii

Acetogens such as Clostridium ljungdahlii can play a crucial role reducing the human CO2 footprint by converting industrial emissions containing CO2 , CO and H2 into valuable products such as organic acids or alcohols. The quantitative understanding of cellular metabolism is a prerequisite to exploit the bacterial endowments and to fine-tune the cells by applying metabolic engineering tools. Studying the three gas mixtures CO2  + H2 , CO and CO + CO2  + H2 (syngas) by continuously gassed batch cultivation experiments and applying flux balance analysis, we identified CO as the preferred carbon and electron source for growth and producing alcohols. However, the total yield of moles of carbon (mol-C) per electrons consumed was almost identical in all setups which underlines electron availability as the main factor influencing product formation. The Wood-Ljungdahl pathway (WLP) showed high flexibility by serving as the key NAD+ provider for CO2  + H2, whereas this function was strongly compensated by the transhydrogenase-like Nfn complex when CO was metabolized. Availability of reduced ferredoxin (Fdred ) can be considered as a key determinant of metabolic control. Oxidation of CO via carbon monoxide dehydrogenase (CODH) is the main route of Fdred formation when CO is used as substrate, whereas Fdred is mainly regenerated via the methyl branch of WLP and the Nfn complex utilizing CO2  + H2 . Consequently, doubled growth rates, highest ATP formation rates and highest amounts of reduced products (ethanol, 2,3-butanediol) were observed when CO was the sole carbon and electron source.

Clathrates of TETROL: selective inclusion of methylcyclohexanones in their energetically unfavorable axial methyl conformations

TETROL, surprisingly, includes 3- and 4-methylcyclohexanone exclusively in their energetically disfavoured axial conformations.

Elevated aqueous humour tissue inhibitor of matrix metalloproteinase-1 and connective tissue growth factor in pseudoexfoliation syndrome

BACKGROUND/AIMS

Pseudoexfoliation syndrome (PXF) was recently found to be associated with increased expression of transforming growth factor beta(1) (TGFbeta(1)) in the aqueous humour. As concern has been raised regarding anti-TGFbeta therapy, which can potentially disrupt the maintenance of anterior chamber associated immune deviation, the authors explored the levels of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and connective tissue growth factor (CTGF) in aqueous humour to determine if these may represent alternative therapeutic targets.

METHODS

Aqueous humour samples were collected from patients who underwent routine cataract surgery. All patients were categorised into three main groups-PXF, uveitis, and control. The PXF group was further subcategorised into three grades based on the density of the exfoliative material observed on biomicroscopy, as well as the presence or absence of glaucoma. TIMP-1, MMP-9, and CTGF levels were measured using specific enzyme immunoassays (ELISA).

RESULTS

Eyes with PXF had significantly higher aqueous humour TIMP-1 concentration (n = 56, mean (SE), 9.76 (1.10) ng/ml) compared with controls (n = 112, 5.73 (0.43) ng/ml, p<0.01). Similarly, the CTGF level in PXF eyes (n = 36, 4.38 (0.65) ng/ml) was higher than controls (n = 29, 2.35 (0.46) ng/ml, p<0.05). Further, the CTGF concentration in the PXF glaucoma group is significantly higher compared with PXF eyes without glaucoma (6.03 (1.09) ng/ml v 2.73 (0.45) ng/ml, p<0.01). The MMP-9 levels were low and below detection limit in all PXF and control samples with no statistical difference between groups.

CONCLUSION

A raised TIMP-1 level and a low MMP-9 level in aqueous humour of PXF eyes may imply a downregulation in proteolytic activity. The increased CTGF concentration supports the proposed fibrotic pathology of PXF. Regulation of MMP/TIMP expression and anti-CTGF therapy may offer potential therapeutic avenues for controlling PXF associated ocular morbidity.

Nuclear RNAs confined to a reticular compartment between chromosome territories

RNA polymerase II transcripts are confined to nuclear compartments. A detailed analysis of the nuclear topology of RNA from individual genes was performed for transcripts from the marker gene coding for chloramphenicol acetyltransferase, expressed at a high level from the HTLV-1 LTR promoter. The construct was transfected into A293 cells where the RNA was organized as an extensive reticular network. We also studied the RNA distribution from combinations of neighboring HIV and bacterial resistance genes that co-integrated within the genome of COS-7 cells-revealing spherical or track-like accumulations of RNA that were extensively branched. There were many nuclei with distinct but overlapping RNA accumulations. Since the coding genes localized at the overlapping points, the RNAs are synthesized at a common region and diverge. The correlation between the frequency of the separation of the transcripts and the physical distance of the respective genes suggests a subcompartmentalization in the microenvironment of genes on the basis of geometric parameters. Thus, the more distant the genes are on the same chromosome, the more likely they are confined to separated subcompartments of an extensive reticular system. Co-delineation of the RNA transcripts with Cajal bodies and chromosome territories indicated the organization of nuclear RNA transcripts in a reticular interchromosome domain compartment.

Fliih, the murine homologue of the Drosophila melanogaster flightless I gene: nucleotide sequence, chromosomal mapping and overlap with Llglh

The Drosophila melanogaster flightless I gene is involved in cellularization processes in early embryogenesis and in the structural organization of indirect flight muscle. The encoded protein contains a gelsolin-like actin binding domain and an N-terminal leucine-rich repeat protein-protein interaction domain. We have cloned Fliih, the corresponding chromosomal gene from the mouse, and determined its nucleotide sequence (15.6 kb). The predicted Fliih protein of 1271 amino acids is 95% identical to the human FLII protein. Like the human gene, Fliih has 29 introns, compared with 13 in C. elegans and 3 in D. melanogaster. Fluorescence in situ hybridization was used to map Fliih to Chromosome 11B. Fliih lies adjacent to Llglh, the mouse homologue of the D. melanogaster tumor suppressor gene lethal(2) giant larvae. The sequence of the genomic DNA in this area, combined with cDNA sequences, establishes that the 3' ends of the Fliih and Llglh transcripts overlap. The overlap region contains polyA signals for both genes and is conserved between human and mouse.

Correlation of estradiol, parathyroid hormone, interleukin-6, and soluble interleukin-6 receptor during the normal menstrual cycle

Rodent models suggest that estradiol deficiency promotes bone loss through increasing interleukin-6 (IL-6) activity. However, it is controversial as to whether these findings are applicable to humans. To evaluate estradiol-mediated modulation of IL-6 activity in relation to bone metabolism in humans, we measured serum IL-6, soluble interleukin-6 receptor (sIL-6R), estradiol (E2), progesterone, luteinizing hormone, follicle-stimulating hormone, intact parathyroid hormone (PTH), serum and urine Ca, and bone biochemical markers (serum bone-specific alkaline phosphatase, osteocalcin, and serum and urine deoxypyridinoline [Dpd]) across one menstrual cycle for 211 women. Neither IL-6 nor sIL-6R levels differed between the follicular phase (FP) and the luteal phases (LP). However, IL-6 was negatively correlated with E2 during the FP (p =0.003). Furthermore, IL-6 correlated positively with serum Ca over the entire cycle (p = 0.0091. Serum Ca correlated positively with serum (p = 0.040) and urine (p = 0.006) Dpd. PTH was significantly higher during the FP than in the LP (p = 0.004). PTH was negatively related to E2 (p = 0.002), serum Ca (p < 0.001), and urine Ca (p = 0.036), whereas it was positively correlated with IL-6 (p = 0.027). These data demonstrate that IL-6 and PTH fluctuate with E2, and serum II-6 is associated with PTH levels during the menstrual cycle. However, the role of 11-6 in bone remodeling during the normal menstrual cycle remains to be determined.

Human eukaryotic initiation factor EIF2C1 gene: cDNA sequence, genomic organization, localization to chromosomal bands 1p34-p35, and expression

We report the cloning and characterization of the human eukaryotic protein translation initiation factor EIF2C1 gene. The human EIF2C1 gene consists of 19 exons and 18 introns that span a region of almost 50 kb. It is located on the short arm of chromosome 1 in the region 1p34-p35. This genomic region is frequently lost in human cancers such as Wilms tumors, neuroblastoma, and carcinomas of the breast, liver, and colon. The human EIF2C1 gene is ubiquitously expressed at low to medium levels. Differential polyadenylation and splicing result in a complex transcriptional pattern. The cDNA sequence is 7478 bp long and contains an extremely large 3' untranslated region of 4799 bp with multiple, short repeated segments composed of mono-, tri-, or quattronucleotides interspersed throughout. The human EIF2C1 gene belongs to a multigene family in human. It is highly conserved during evolution, sharing about 90% identity with rabbit eIF2C and 70% identity with plant AGO1 at the amino acid level. These facts suggest that human EIF2C1 might play an important physiological role.

Direct visual resolution of gene copy number in the human photopigment gene array

PURPOSE

To visualize by direct fluorescent in situ hybridization the entire human visual pigment gene array on single X-chromosome fibers and to compare the results with values obtained by other molecular techniques.

METHODS

The size of the opsin gene array on the X-chromosome in eight male subjects was investigated by (i) direct visual in situ hybridization (DIRVISH) on elongated DNA fibers: (ii) quantitation of genomic restriction fragments after Southern blot hybridization; (iii) quantitation of restriction fragment length polymorphism after PCR amplification (PCR/RFLP), and (iv) sizing of NotI fragments by pulsed field gel electrophoresis and Southern blot detection. Each male subject's color vision was assessed by Rayleigh matches on a Nagel Type 1 anomaloscope.

RESULTS

The number of genes resolved by the DIRVISH protocol, which ranges from 1 to 6, agrees exactly with the gene array sizes obtained in the same male subjects from pulsed field gel electrophoresis, but differs from the estimates derived from the commonly used indirect Southern blot hybridization and PCR/RFLP quantitation methods. In particular, the PCR/RFLP method overestimates the copy number in all but the smallest arrays.

CONCLUSIONS

Visualization of the X-chromosome opsin gene array by DIRVISH provides a new, direct method for obtaining exact copy numbers and helps to resolve the controversy about the range and the average visual pigment gene number in the human population in favor of smaller average array sizes.

Changes in bone resorption during the menstrual cycle

To determine if the cyclic changes of female sex hormones during the menstrual cycle are related to changes in bone formation and resorption, we measured serum bone-specific alkaline phosphatase (BAP) and osteocalcin (OC) and bone resorption markers, serum and urine deoxypyridinoline (Dpyr), three times per week during one menstrual cycle in 20 healthy premenopausal women. Serum estradiol (E2) and progesterone (P) showed characteristic cyclic fluctuations. Serum Dpyr was higher during the follicular phase (FP) than in the luteal phase (p = 0.027). Serum BAP, OC, and urine Dpyr levels did not change substantially across the cycle. Serum Dpyr correlated negatively with serum E2 values measured 6 (p = 0.011) and 8 (p = 0.001) days earlier and with P measured concurrently (p = 0.033) 2 (p = 0.002), 4 (p = 0.003), and 6 (p = 0.014) days earlier. BAP correlated negatively with E2 measured 6 days earlier (p = 0.006). We found no statistically significant correlations of E2 or P with OC or urine Dpyr within women over their cycles. BAP was positively correlated with concurrent serum Dpyr (p = 0.015) during the menstrual cycle. Serum OC levels correlated inversely with age (rs = -0.48, p = 0.036). Women with higher mean urine Dpyr levels had higher mean serum OC levels (rs = 0.49, p = 0.033) and showed a trend toward lower hip bone mineral density (rs = -0.40, p = 0.078). We conclude that the low level of E2 and/or P observed during the FP of the normal menstrual cycle is associated with increased bone resorption. These relationships suggest that normal women experience monthly episodes of increased bone resorption from menarche to menopause.

Factors influencing stay in the postanesthesia care unit: a prospective analysis

STUDY OBJECTIVE

To identify indicators of prolonged length of stay (LOS) in the postanesthesia care unit (PACU) and to test the following hypotheses: (1) that patient age, pain medication administration at the time of PACU admission, length of surgery, and cardiovascular, pulmonary, and pain responses postoperatively predict prolonged PACU LOS and (2) that cardiovascular and pulmonary symptoms preoperatively predict cardiovascular and pulmonary symptoms postoperatively.

DESIGN

Prospective, observational analysis.

SETTING

PACU of a university teaching hospital.

PATIENTS

1,067 patients scheduled for surgery with general anesthesia between February and September 1996, 18 years of age or older.

MEASUREMENT AND MAIN RESULTS

11.2% of the variation in prolonged PACU LOS can be predicted by age, pain medication at the time of PACU admission, and postoperative cardiovascular, pulmonary, and pain symptoms. A significant number of patients who did not report a prior history experienced postoperative cardiovascular and pulmonary symptoms.

CONCLUSION

Patient history and postoperative symptoms predict only a small percentage of prolonged PACU stays. Organizational factors may be a more important predictor of prolonged PACU stay. Additionally, assessment of cardiovascular and pulmonary history needs refinement to improve prediction of patient responses postoperatively.

Expressed sequences as candidates for a novel tumor suppressor gene at band 13q14 in B-cell chronic lymphocytic leukemia and mantle cell lymphoma

Deletions affecting the interval between the RB1 gene and marker D13S25 at band 13q14 are the most frequent genetic abnormalities of B-cell chronic lymphocytic leukemia (B-CLL) and indicate the presence of a novel tumor suppressor gene in this region. In the current study, a high resolution physical map of fragments spanning one megabasepair (Mb) of genomic DNA at the critical 13q14 segment was constructed. To define the minimal region of loss within the RB1 and D13S25 interval, we screened 322 B-CLLs for deletions at either of the two loci. Thirty mantle cell lymphomas (MCLs) were included in the analysis because we observed a 13q14 deletion pattern similar to B-CLL in this disease. The incidence of 13q14 deletions was 51% in B-CLL and 70% in MCL, respectively. No frequent loss of the BRCA2 gene at band 13q12 was found. Detailed deletion mapping at band 13q14 with probes from the RB1-D13S25 interval lead to the identification of a critical deletion region 400 kb in size. Within this region two segments were most frequently affected, one at D13S272 120 kb in size and another 240 kb distal of D13S272 80 kb in size. From these two segments expressed sequences were identified as candidates for the putative 13q14 tumor suppressor gene involved in the pathogenesis of B-CLL and MCL.

Acute withdrawal syndrome related to the administration of analgesic and sedative medications in adult intensive care unit patients

OBJECTIVES

To estimate the frequency of acute withdrawal syndrome related to the administration of analgesic and sedative medications in mechanically ventilated adult intensive care unit (ICU) patients; to identify associated clinical factors.

DESIGN

Retrospective review of medical records.

SETTING

An adult trauma/surgical ICU in an urban Level I trauma center.

PATIENTS

Twenty-eight mechanically ventilated adult trauma/ surgical ICU patients requiring >7 days of ICU care.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily doses of all opioid, sedative, hypnotic, and major tranquilizer drugs administered to each patient were measured, as was duration of ICU stay, duration of mechanical ventilation, and duration of the administration of analgesic, sedative, and neuromuscular blocking agents (NMBAs) for each patient. All opioids and benzodiazepines were converted to their respective fentanyl and lorazepam equivalent units based on potency and bioavailability. Calculation of the weaning rate for each patient during tapering from opioid and benzodiazepine medications was performed. The presence or absence of acute withdrawal syndrome was identified for each patient. Nine (32.1%) patients developed acute withdrawal syndrome potentially related to the administration of analgesic or sedative medications. Patients in the withdrawal group received significantly higher mean daily (p = .049) and peak (p = .032) doses of fentanyl equivalents, as well as higher mean daily lorazepam equivalents (p = .049) compared with patients not experiencing withdrawal. Patients in the withdrawal group were also significantly more likely to have received neuromuscular blocking agents (p = .004) or propofol (p =.026) for >1 day during ICU admission compared with patients not experiencing withdrawal. Duration of mechanical ventilation (p = .049), benzodiazepine therapy (p = .048), and propofol therapy (p = .049) was also significantly longer in the group experiencing withdrawal. Withdrawal patients received a significantly lower mean daily dose of haloperidol (p = .026). There was a significant association between the development of withdrawal syndrome and the presence of ARDS (p = .017). Finally, the slopes of the lines representing opioid and benzodiazepine drug weaning were more steep for the withdrawal group, although these results did not achieve statistical significance.

CONCLUSIONS

These results suggest that mechanically ventilated adult patients with extended ICU care (> or =7 days) who receive large doses of analgesic and sedative medications are at risk for acute withdrawal syndromes during drug weaning. The association between ARDS and withdrawal syndrome, combined with the observation that withdrawal syndromes were also associated with the use of neuromuscular blocking agents and prolonged mechanical ventilation, suggests that patients with ARDS may be more likely to receive high doses of analgesic and sedative medications, and are therefore at increased risk for withdrawal syndrome.

APM-1, a novel human gene, identified by aberrant co-transcription with papillomavirus oncogenes in a cervical carcinoma cell line, encodes a BTB/POZ-zinc finger protein with growth inhibitory activity

Integration of human papillomavirus (HPV) DNA into the host cell genome is an important step in cervical carcinogenesis. In tumour cells with integrated HPV DNA, transcription of viral oncogenes E6 and E7 continues into the flanking cellular sequences thereby producing viral-cellular fusion transcripts. Analysis of cellular sequences flanking the integrated HPV68 DNA in the cervical carcinoma cell line ME180 revealed homozygosity of the mutant allele in ME180 cells. We speculated that this could indicate the existence of a cellular tumour suppressor gene in the integration region. We report here the identification of a novel human gene, named APM-1, which is co-transcribed with the HPV68 E6 and E7 genes and is present in the 3'-cellular part of the ME180 viral-cellular fusion transcripts. The APM-1 gene encodes a protein with a BTB/POZ domain and four zinc fingers, and is located at chromosome 18q21. APM-1 transcripts are detected in normal cervical keratinocytes, but not in the majority of cervical carcinoma cell lines analysed. The APM-1 gene caused a reduction of clonal cell growth in vitro of HeLa and CaSki tumour cells. These characteristics make APM-1, the first novel human gene identified in a HPV integration region, a likely candidate for the postulated tumour suppressor gene.

Influence of circulating c-erbB-2 serum protein on response to adjuvant chemotherapy in node-positive breast cancer patients

This retrospective case control study investigated the therametric value of the circulating c-erbB-2 gene product (Her-2, NEU) as (1) an eligibility criterion for high doses of chemotherapy and (2) response to standard adjuvant chemotherapy in node-positive breast cancer patients. Preoperative c-erbB-2 levels were measured in 211 locally advanced (> 3 nodes positive), pre- and perimenopausal breast cancer patients to determine if circulating levels of the gene product can assist in the determination of appropriate therapeutic options. 152 of 211 breast cancer patients received post-operatively a combination chemotherapy including the anthracycline analog mitoxantrone, while 59 patients were treated with conventional CMF therapy. Using 120 fmol/ml as a cut-off level, elevated c-erbB-2 values were found in 26 (12.3%) patients with locally advanced breast cancer. In univariate analysis significant survival differences were detected when c-erbB-2 'positive' patients were compared with c-erbB-2 'negative' patients. However, no significant survival differences were detected, when c-erbB-2 'positive' patients were compared according to regimen of adjuvant treatment. In multivariate analysis c-erbB-2 was an independent prognostic factor for predicting disease-free survival, but not for overall survival. High levels of c-erbB-2 were associated with low estrogen and progesterone receptor concentrations of the tumor cytosol. There was no correlation between elevated c-erbB-2 values and age, tumor size or degree of nodal involvement. c-erbB-2 was a better predictor of risk of recurrence than extent of nodal involvement or hormone receptor status.

Sequence, genomic organization, and chromosomal localization of the human LPAP (PTPRCAP) and mouse CD45-AP/LSM-1 genes

Human LPAP (lymphocyte phosphatase associated phosphoprotein) and its mouse homologue, CD45-AP (CD45 associated protein) or LSM-1, represent 32- and 30-kDa transmembrane phosphoproteins that noncovalently associate with the tyrosine phosphatase CD45, a key molecule involved in T- and B-lymphocyte activation. Here we report the isolation and sequencing of genomic clones of the human and mouse genes. LPAP (HGMW-approved symbol PTPRCAP) maps to human chromosome 11q13, distal to the BCL-1 breakpoint, and mouse CD45-AP/LSM-1 maps to Chromosome 19B. Both genes span 3 kb and consist of two exons that are separated by a 1.2-kb intron. The promoter regions do not contain TATA boxes, but possess consensus transcriptional initiator sequences that have also been described for other TATA-less genes. The genomic sequences also provide a genetic basis for two different cDNAs (termed CD45-AP and LSM-1, respectively) that have been described in the mouse system.

The mouse fkh-2 gene. Implications for notochord, foregut, and midbrain regionalization

The "winged helix" or "forkhead" transcription factors comprise a large gene family whose members are defined by a common 100-amino acid DNA binding domain. Here we describe the structure and expression of the mouse fkh-2 gene, which encodes a protein of 48 kDa with high similarity to other winged helix transcription factors within the DNA binding region, but unique potential transactivation domains. The gene is encoded by a single exon and is expressed in headfold stage embryos in the notochord, the anterior neuroectoderm, and a few cells of the definite endoderm. This expression becomes restricted to the anteriormost portions of the invaginating foregut and the developing midbrain. From day 11.5 of gestation onward, fkh-2 transcripts are restricted to the midbrain and become progressively localized to the red nuclei as the sole site of expression. The fkh-2 gene maps to chromosome 19B and is a candidate gene for the mouse mutation mdf (muscle-deficient) which is characterized by nervous tremors and degeneration of the hindlimb muscles. Although the expression patterns of the fkh-2 gene and another winged helix protein, HNF-3 beta, are overlapping in early stages of gestation and although the promoter of the fkh-2 gene contains a HNF-3 binding site, we demonstrate that the activation of the fkh-2 gene is independent of HNF-3 beta.

Postoperative pain management

OBJECTIVES

To examine the relationship between analgesia and clinical outcome and to review new methods of delivering opioid analgesics and new pharmacologic analgesic agents.

DATA SOURCES

A computer-assisted search of the literature on postoperative pain management, and a review of those areas in which new approaches have led to a change in clinical practice.

RESULTS

Current research focuses on the ability of analgesia to decrease perioperative complications. Recent advances allow enhanced postoperative analgesia with a low incidence of side effects. Administration of opioids via a patient-controlled device or via an epidural catheter yields excellent analgesia with a low rate of side effects compared with intramuscular opioids. Several non-narcotic, parenteral drugs, including ketorolac tromethamine and alpha 2-adrenergic agonists are now available. These drugs decrease opioid requirement, and thus the rate of serious side effects, including respiratory depression. Moreover, because these drugs act at sites other than opioid receptors, they may enhance the quality of analgesia at the same time they decrease opioid requirement.

CONCLUSIONS

New technology and new agents allow more rational management of postoperative pain. Use of these techniques results in increased patient satisfaction and may improve clinical outcome.

High frequency of monoallelic retinoblastoma gene deletion in B-cell chronic lymphoid leukemia shown by interphase cytogenetics

Inactivation of the retinoblastoma tumor-suppressor gene (RB-1) has been associated with tumorigenicity in various human malignancies. In chronic lymphoid leukemias of B-cell origin (B-CLL) an involvement of RB-1 has been suggested based on cytogenetic data. We examined RB-1 and its chromosomal locus 13q14 in 35 cases of B-CLL by dual-color in situ hybridization to interphase nuclei and by G-banding analysis of metaphase chromosomes. In one patient (pt) a monosomy 13, and in three other pts deletions involving or encompassing band 13q14 were detected by conventional cytogenetic analysis. In contrast, in situ hybridization to interphase nuclei showed a monoallelic RB-1 deletion in 11 cases (31%). One pt showed a translocation with the breakpoint in 13q1?4 on G-banding, but on in situ hybridization analysis the RB-1 signals were not affected. Our data show that RB-1 deletions can be diagnosed accurately by in situ hybridization on the one-cell level. The frequency of RB-1 deletions detected in this study is significantly higher than previously assumed in B-CLL, and seems to be in the same range as in retinoblastoma.

Immunoassay for thymidylate synthase in cytosols from human colorectal-carcinoma cell-lines

Thymidylate synthase (TS) is an essential enzyme for DNA biosynthesis that is an important target of fluoropyrimidine anti-cancer drugs such as 5-fluorouracil (5-FU), which is frequently used against human colon adenocarcinomas. Because levels of TS in such tumors may be predictive of chemotherapeutic response to 5-FU, it is desirable to have a method for TS quantitation simpler than the laborious conventional biochemical assays that currently exist. We therefore describe a rapid and simple immunoassay for quantitating human TS (in cell or tissue extracts) that employs a rabbit antibody to TS from bacteriophage T4 and an automated colorimetric readout. The sensitivity of the assay is demonstrated by its ability to show a different TS level in cytosols from each of 8 human colorectal carcinoma cell lines tested and a 2.5-fold difference between the highest and lowest values observed. Western immunoblot was used to show that the rabbit antibody to T4 TS cross-reacts very specifically with human TS enzyme. This indicates that some evolutionarily conserved (phage or bacterial) enzymes, not purified from human sources, may be useful as antigens in producing anti-sera for human diagnostic tests.

Cathepsin D expression detected by immunohistochemistry has independent prognostic value in axillary node-negative breast cancer

PURPOSE

Increased expression of the lysosomal protease cathepsin D (CD) has been implicated in the metastatic progression of breast cancer. This study was designed to determine the prognostic significance of CD expression in axillary node-negative (ANN) breast cancer. The relationship of CD expression and onset of soft tissue recurrences and visceral metastatases was also studied.

PATIENTS AND METHODS

We analyzed a population-based group of 262 ANN breast cancer patients, none of whom had received any adjuvant chemotherapy or endocrine therapy. An immunohistochemical method based on a new monoclonal antibody (1C11) with a distinct epitope specificity made it possible to study CD expression from archival paraffin-embedded specimens and to distinguish staining in tumor cells from the high-level expression found in tumor-infiltrating macrophages.

RESULTS

High-level CD expression, as defined by cytoplasmic immunoreactivity in greater than 10% of the cancer cells, was found in 95 cases (36%). High-level CD expression was associated with large primary tumor size (P = .014), but not with histologic grade, estrogen and progesterone receptors, DNA index, or S-phase fraction, or with c-erbB-2 and p53 overexpression. Patients with CD-positive tumors developed significantly more often both soft tissue recurrences and visceral metastases (P = .0007) and had a significantly shorter disease-free survival (P < .0001). Eight-year overall survival of patients with high-level CD expression was 64% as compared with 90% in those with low-level expression (relative risk, 2.97; 95% confidence interval [Cl], 1.6 to 4.4; P < .0001). According to a Cox multivariate model and a regression-tree analysis, high-level CD expression was an independent predictor of poor overall survival in conjunction with tumor size and S-phase fraction.

CONCLUSION

These results indicate that CD expression determined by immunohistochemistry is a powerful prognostic factor in ANN breast cancer. The most significant prognostic information was obtained when CD expression (predicting metastatic activity) was combined with estimate of cell-proliferation rate (S-phase fraction).

The human APO-1 (APT) antigen maps to 10q23, a region that is syntenic with mouse chromosome 19

The APO-1 (APT) antigen is a cell surface antigen expressed on a variety of normal and malignant cells. Binding of anti-APO-1 antibody to the APO-1 antigen induces programmed cell death (apoptosis). The APO-1 antigen shows homology to the members of the tumor necrosis factor receptor/nerve growth factor receptor superfamily. Using cosmid DNA containing the APO-1 gene as a probe for fluorescence in situ hybridization, we have mapped the gene to a subregion of chromosomal band 10q23. The human APO-1 locus lies within a conserved synteny segment present on mouse chromosome 19 consistent with the previous chromosomal assignment of the corresponding mouse antigen.

Human perforin (PRF1) maps to 10q22, a region that is syntenic with mouse chromosome 10

Perforin (PRF1) is a cytolytic, channel-forming protein of cytolytic T cells, natural killer cells, and granulated metrial gland cells and plays a crucial role in the killer cell-mediated elimination of virally infected host cells, tumor cells, and allotransplants. Two-thirds of the perforin sequence is homologous to the lytic, channel-forming complement proteins C6, C7, C8 alpha, C8 beta, and C9. Using cosmid DNA containing the PRF1 gene as a probe for fluorescence in situ hybridization, we have reevaluated its chromosomal location. Previously assigned to chromosome 17q11-q21, it has now been mapped to 10q22. The human PRF1 locus lies within a conserved synteny segment present on mouse chromosome 10, consistent with the previous chromosomal assignment of mouse perforin. The perforin locus is not linked to any of the genes of the terminal complement system.

Human casein kinase II subunit alpha: sequence of a processed (pseudo)gene and its localization on chromosome 11

A human 4.3 kb genomic DNA fragment, containing the information of a processed (pseudo)gene of casein kinase II subunit alpha (CKII alpha) was isolated and sequenced. The genomic CKII alpha sequence is 99% homologous to the CKII alpha cDNA, carries several nucleotide exchanges, a poly(A) stretch at its 3' end and is flanked at both ends by a 16 bp repeat. It has a promoter-like region including two TATA boxes and a CAAT box. Although translation of transcripts would be terminated by a stop codon after two third of the coding region, the resulting protein would still contain the catalytic domains. However, so far Northern blots with a 3' specific probe were negative. The 4.3 kb genomic fragment containing the processed CKII alpha (pseudo)gene was mapped by in situ hybridization to chromosome 11p15.

Cerebral granular cell tumor: immunohistochemical and electron microscopic study

A rare intracerebral granular cell tumor (GCT) was studied by immunocytochemical and ultrastructural methods. The tumor was composed of two cell types--filament-rich and granular cells. Granular cells contained PAS-positive, diastase-resistant granules that ultrastructurally corresponded to autophagic cytosegresomes. Glial fibrillary acidic protein, the intermediate filament protein specific for astrocytes, was demonstrated in the filament-rich and, to a lesser extent, in the granular cells. Unlike noncerebral GCT, neither S-100 protein nor vimentin was detected in the tumor cells. On the other hand, both cerebral and noncerebral GCT were labeled immunocytochemically with peanut lectin (Arachis hypogaea). The results suggest that cerebral GCT share some features with noncerebral GCT, but differ in other respects. They further suggest that GCT may be derived from different cell types depending on the tissue of origin, and that cerebral GCT may be derived from astrocytes.

Rhinorrhea and pneumocephalus after cerebrospinal fluid shunting. The role of lateral extensions of the sphenoid sinus

Pneumocephalus is usually seen after trauma or neurologic surgery. A rare presentation is after cerebrospinal fluid (CSF) shunting for rhinorrhea. This may be a manifestation of shunt malfunction or of the failure to close a preexisting fistulous tract. A common site of failure is the sphenoid sinus, where CSF may leak from a dehiscence in the middle cranial fossa floor. These dehiscences often communicate with lateral extensions of the sphenoid. This complication is best managed by craniotomy with direct inspection of the floor of the middle cranial fossa and correction of deranged CSF dynamics.

Cerebrospinal fluid dynamics and rhinorrhea: the role of shunting in repair

CSF rhinorrhea can have many causes: traumatic, neoplastic, and iatrogenic origins are common. Most traumatic rhinorrhea ceases after a trial of conservative management. While obvious erosion or traumatic destruction of vital structures may be the underlying cause, other pathophysiologic mechanisms may be working in the formation of CSF rhinorrhea, which may require the combined skills of the otolaryngologist and the neurosurgeon. Leakage of CSF is seen in "high-pressure rhinorrhea," a pathophysiologic state wherein the underlying problem is poor CSF resorption. The result is increased intracranial pressure and eventual rhinorrhea or otorrhea. Areas of CSF leakage correspond to sites of congenital weakness in the cribriform plate region, the parasellar region, or the temporal bone. Weak areas in old base-of-skull fracture sites may leak with increased intracranial pressure. The initial management should stress correction of the deranged pathophysiology, namely shunting. Surgical repair is secondary to controlling the abnormal CSF dynamics.

The acquisition of language skills by autistic children: can parents do the job?

The mothers and fathers of 11 preschool autistic children were taught operant procedures used in teaching speech to nonverbal children. The children's speech skills were assessed twice before and once after their parents were trained. At posttreatment, the children showed significant gains in prespeech and speech skills as measured by a 21-step hierarchy of speech behaviors. Those children who had acquired at least verbal imitative skill after training made greater progress than those who had not. Although children maintained their gains in a 1-year follow-up assessment, there was no evidence of significant improvement beyond that achieved at the end of training. The importance of support for parents in continuing to do formal "teaching" after the training program ends was stressed.