Structural and immunological characterization of an epitope within the PAN motif of ectodomain I in Babesia bovis apical membrane antigen 1 for vaccine development

Background

Bovine babesiosis caused by Babesia bovis (B. bovis) has had a significant effect on the mobility and mortality rates of the cattle industry worldwide. Live-attenuated vaccines are currently being used in many endemic countries, but their wide use has been limited for a number of reasons. Although recombinant vaccines have been proposed as an alternative to live vaccines, such vaccines are not commercially available to date. Apical membrane antigen-1 (AMA-1) is one of the leading candidates in the development of a vaccine against diseases caused by apicomplexan parasite species. In Plasmodium falciparum (P. falciparum) AMA-1 (PfAMA-1), several antibodies against epitopes in the plasminogen, apple, and nematode (PAN) motif of PfAMA-1 domain I significantly inhibited parasite growth. Therefore, the purpose of this study was to predict an epitope from the PAN motif of domain I in the B. bovis AMA-1 (BbAMA-1) using a combination of linear and conformational B-cell epitope prediction software. The selected epitope was then bioinformatically analyzed, synthesized as a peptide (sBbAMA-1), and then used to immunize a rabbit. Subsequently, in vitro growth- and the invasion-inhibitory effects of the rabbit antiserum were immunologically characterized.

Results

Our results demonstrated that the predicted BbAMA-1 epitope was located on the surface-exposed α-helix of the PAN motif in domain I at the apex area between residues 181 and 230 with six polymorphic sites. Subsequently, sBbAMA-1 elicited antibodies capable of recognizing the native BbAMA-1 in immunoassays. Furthermore, anti-serum against sBbAMA-1 was immunologically evaluated for its growth- and invasion-inhibitory effects on B. bovis merozoites in vitro. Our results demonstrated that the rabbit anti-sBbAMA-1 serum at a dilution of 1:5 significantly inhibited (p < 0.05) the growth of B. bovis merozoites by approximately 50–70% on days 3 and 4 of cultivation, along with the invasion of merozoites by approximately 60% within 4 h of incubation when compared to the control groups.

Conclusion

Our results indicate that the epitope predicted from the PAN motif of BbAMA-1 domain I is neutralization-sensitive and may serve as a target antigen for vaccine development against bovine babesiosis caused by B. bovis.

Does dissemination of guidelines alone increase the use of palliative single-fraction radiotherapy? Initial report of a longitudinal change management campaign at a provincial cancer program

Background

Despite level 1 evidence demonstrating the equivalence of single-fraction radiotherapy (sfrt) and multiple-fraction radiotherapy (mfrt) for the palliation of painful bone metastases, sfrt remains underused. In 2015, to encourage the sustainable use of palliative radiation oncology resources, CancerCare Manitoba disseminated, to each radiation oncologist in Manitoba, guidelines from Choosing Wisely Canada (cwc) that recommend sfrt. We assessed whether dissemination of the guidelines influenced sfrt use in Manitoba in 2016, and we identified factors associated with mfrt.

Methods

All patients treated with palliative radiotherapy for bone metastasis in Manitoba from 1 January 2016 to 31 December 2016 were identified from the provincial radiotherapy database. Patient, treatment, and disease characteristics were extracted from the electronic medical record and tabulated by fractionation schedule. Univariable and multivariable logistic regression analyses were performed to identify risk factors associated with mfrt.

Results

In 2016, 807 patients (mean age: 70 years; range: 35-96 years) received palliative radiotherapy for bone metastasis, with 69% of the patients having uncomplicated bone metastasis. The most common primary malignancies were prostate (27.1%), lung (20.6%), and breast cancer (15.9%). In 62% of cases, mfrt was used-a proportion that was unchanged from 2015. On multivariable analysis, a gastrointestinal [odds ratio (or): 5.3] or lung primary (or: 3.3), complicated bone metastasis (or: 4.3), and treatment at a subsidiary site (or: 4.4) increased the odds of mfrt use.

Conclusions

Dissemination of cwc recommendations alone did not increase sfrt use by radiation oncologists in 2016. A more comprehensive knowledge translation effort is therefore warranted and is now underway to encourage increased uptake of sfrt in Manitoba.

In search of the vector(s) of Babesia rossi in Nigeria: molecular detection of B. rossi DNA in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) ticks collected from dogs, circumstantial evidence worth exploring

The brown dog tick Rhipicephalus sanguineus (sensu lato) (Acari: Ixodidae) has a cosmopolitan distribution, is a proven vector of a host of pathogens with emerging evidence incriminating it in the transmission of some others. Specifically it is reputed as the main vector of Babesia vogeli whereas the southern African yellow dog tick Haemaphysalis elliptica, long considered to be H. leachi, is apparently the only proven vector of B. rossi, since the resurrection of the separate species H. elliptica as a member of the leachi-group by Apanaskevich et al. However, recent epidemiological surveys conducted in Nigeria show higher prevalence of B. rossi than B. vogeli infection in dogs most of whom were infested with R. sanguineus and rarely with ticks of the H. leachi group. The discrepancy between tick distribution and Babesia spp. prevalent in dogs stimulated us to investigate the possible role of R. sanguineus (s.l.) in the natural transmission of B. rossi. Out of a total of 66 tick samples identified morphologically and molecularly as R. sanguineus collected from dogs manifesting clinical signs of tick-borne diseases, eight (12%) were positive in nested PCR for Babesia sp. DNA. Sequencing results for these amplified products showed that all of the 18S rDNA sequences (693 bp) were identical to each other, and bore 99.3-99.9% identities with those from other B. rossi isolates accessible in GenBank. None of the ticks harbored the DNA of B. vogeli or B. canis. The possible implications for the detection of B. rossi DNA in R. sanguineus (s.l.) ticks collected from dogs in the epidemiology of B. rossi infection of dogs in Nigeria is highlighted.

Low levels of genetic diversity associated with evidence of negative selection on the Babesia bovis apical membrane antigen 1 from parasite populations in Thailand

Babesia bovis, a parasite infecting cattle and buffalo, continues to spread throughout the developing world. The babesial vaccine was developed to be a sustainable alternative treatment to control the parasite. However, genetic diversity is a major obstacle for designing and developing a safe and effective vaccine. The apical membrane antigen 1 (AMA-1) is considered to be a potential vaccine candidate antigen among immunogenic genes of B. bovis. To gain a more comprehensive understanding of B. bovis AMA-1 (BbAMA-1), three B. bovis DNA samples were randomly selected to characterize in order to explore genetic diversity and natural selection and to predict the antigen epitopes. The sequence analysis revealed that BbAMA-1 has a low level of polymorphism and is highly conserved (95.46-99.94%) among Thai and global isolates. The majority of the polymorphic sites were observed in domains I and III. Conversely, domain II contained no polymorphic sites. We report the first evidence of strong negative or purifying selection across the full length of the gene, especially in domain I, by demonstrating a significant excess of the average number of synonymous (dS) over the non-synonymous (dN) substitutions. Finally, we also predict the linear and conformational B-cell epitope. The predicted B-cell epitopes appeared to be involved with the amino acid changes. Collectively, the results suggest that the conserved BbAMA-1 may be used to detect regional differences in the B. bovis parasite. Importantly, the limitation of BbAMA-1 diversity under strong negative selection indicates strong functional constraints on this gene. Thus, the gene could be a valuable target vaccine candidate antigen.

Host ABC transporter proteins may influence the efficacy of ivermectin and possibly have broader implications for the development of resistance in parasitic nematodes

ABC transporter proteins function to extrude compounds from the cell. These proteins present an obstacle for treatment and for overcoming drug resistance as they are expressed by both host and parasite, and function similarly. The contribution of host ABC proteins to drug efficacy was examined using ivermectin and a Brugia malayi model system. Parallel in vitro and in vivo experiments were conducted using equal concentrations of ivermectin. The motilities and fecundity of B. malayi exposed to ivermectin in vitro were significantly lower than those treated in vivo. The higher motilities were correlated with low concentrations of ivermectin in worms extracted from treated hosts. The expression of ABC proteins was significantly higher in worms treated in vitro compared to those treated in vivo as well as in gerbils treated with ivermectin than in non-treated controls. The results suggest that host ABC transporters may influence the efficacy of ivermectin.

Development of a multiplex amplification refractory mutation system reverse transcription polymerase chain reaction assay for the differential diagnosis of Feline leukemia virus vaccine and wild strains

A multiplex amplification refractory mutation system reverse transcription polymerase chain reaction (ARMS RT-PCR) was developed for the differential diagnosis of Feline leukemia virus (FeLV) vaccine and wild-type strains based on a point mutation between the vaccine strain (S) and the wild-type strain (T) located in the p27 gene. This system was further upgraded to obtain a real-time ARMS RT-PCR (ARMS qRT-PCR) with a high-resolution melt analysis (HRMA) platform. The genotyping of various strains of FeLV was determined by comparing the HRMA curves with the defined wild-type FeLV (strain TW1), and the results were expressed as a percentage confidence. The detection limits of ARMS RT-PCR and ARMS qRT-PCR combined with HRMA were 100 and 1 copies of transcribed FeLV RNA per 0.5 ml of sample, respectively. No false-positive results were obtained with 6 unrelated pathogens and 1 feline cell line. Twelve FeLV Taiwan strains were correctly identified using ARMS qRT-PCR combined with HRMA. The genotypes of the strains matched the defined FeLV wild-type strain genotype with at least 91.17% confidence. A higher degree of sequence polymorphism was found throughout the p27 gene compared with the long terminal repeat region. In conclusion, the current study describes the phylogenetic relationship of the FeLV Taiwan strains and demonstrates that the developed ARMS RT-PCR assay is able to be used to detect the replication of a vaccine strain that has not been properly inactivated, thus acting as a safety check for the quality of FeLV vaccines.

Sequence and phylogenetic analysis of the gp200 protein of Ehrlichia canis from dogs in Taiwan

Ehrlichia (E.) canis is a Gram-negative obligate intracellular bacterium responsible for canine monocytic ehrlichiosis. Currently, the genetic diversity of E. canis strains worldwide is poorly defined. In the present study, sequence analysis of the nearly full-length 16S rDNA (1,620 bp) and the complete coding region (4,269 bp) of the gp200 gene, which encodes the largest major immunoreactive protein in E. canis, from 17 Taiwanese samples was conducted. The resultant 16S rDNA sequences were found to be identical to each other and have very high homology (99.4~100%) with previously reported E. canis sequences. Additionally, phylogenetic analysis of gp200 demonstrated that the E. canis Taiwanese genotype was genetically distinct from other reported isolates obtained from the United States, Brazil, and Israel, and that it formed a separate clade. Remarkable variations unique to the Taiwanese genotype were found throughout the deduced amino acid sequence of gp200, including 15 substitutions occurring in two of five known species-specific epitopes. The gp200 amino acid sequences of the Taiwanese genotype bore 94.4~94.6 identities with those of the isolates from the United States and Brazil, and 93.7% homology with that of the Israeli isolate. Taken together, these results suggest that the Taiwanese genotype represents a novel strain of E. canis that has not yet been characterized.

Allyl isothiocyanate triggers G2/M phase arrest and apoptosis in human brain malignant glioma GBM 8401 cells through a mitochondria-dependent pathway

Isothiocyanates (ITCs) are present as glucosinolates in various cruciferous vegetables. Allyl isothiocyanate (AITC) is one of the common naturally occurring isothiocyanates. Recent studies have shown that AITC significantly inhibited survival of leukemia HL-60, bladder cancer UM-UC-3 and colon cancer HT-29 cells in vitro. In this study, we demonstrate that AITC significantly decreased proliferation and viability of human brain malignant glioma GBM 8401 cells in a dose-dependent manner with IC50 9.25+/-0.69 microM for 24 h-treatment. The analysis of cell cycle distribution also showed that AITC induced significantly G2/M arrest and sub-G1 phase (apoptotic population) in GBM 8401 cells. AITC markedly reduced the CDK1/cyclin B activity and protein levels by CDK1 activity assay and Western blot analysis. AITC-induced apoptotic cell death and this evidence was confirmed by morphological assessment and DAPI staining. Pretreatment with specific inhibitors of caspase-3 (Z-DEVE-FMK) and -9 (Z-LEHD-FMK) significantly reduced caspase-3 and -9 activity in GBM 8401 cells. Western blot analysis and colorimetric assays also displayed that AITC caused a time-dependent increase in cytosolic cytochrome c, pro-caspase-9, Apaf-1, AIF, Endo G and the stimulated caspase-9 and -3 activity. Our results suggest that AITC is a potent anti-human brain malignant glioma drug and it shows a remarkable action on cell cycle arrest before commitment for apoptosis is reached.

Sequence and phylogenetic analysis of the thrombospondin-related adhesive protein (TRAP) gene of Babesia gibsoni isolates from dogs in Taiwan

The genetic diversity of Babesia gibsoni strains worldwide is currently poorly defined. The aim of the present study was to characterize B. gibsoni strains in naturally infected dogs in Taiwan using a combination of polymerase chain reaction (PCR) and sequence analysis of both 18S rDNA and the gene encoding thrombospondin-related adhesive protein (TRAP). Genomic DNA was extracted from 29 parasitemic dogs, and the target genes were separately amplified, sequenced and aligned with corresponding sequences available in GenBank. All 18S rDNA sequences (1,262 bp) amplified from the Taiwanese isolates were identical to each other and had very high similarity (99.9-100%) with previously reported B. gibsoni sequences. These results provide the first molecular evidence showing infection of dogs with B. gibsoni from Taiwan. On the other hand, a phylogenetic analysis based on the deduced amino acid sequence of the TRAP gene demonstrated that the Taiwanese isolates were closely related to strains previously identified from Okinawa Island, Japan, but genetically distinct from strains found on Honshu in Japan and Jeju Island in South Korea. The divergence of TRAP among the geographically dispersed strains examined in this study and others supports the conclusion that this gene is useful for molecular genotyping of B. gibsoni strains.

Detection and characterization of four novel genotypes of Ehrlichia canis from dogs

The genetic diversity of Ehrlichia canis strains worldwide is currently poorly defined. The present study aimed to characterize E. canis strains in naturally infected dogs in Taiwan, using a combination of PCR and sequence analysis of the 16S rDNA and two antigen-encoding genes, gp19 and gp36. Genomic DNA was extracted from 34 parasitemic dogs and the genes of the pathogen were separately amplified, sequenced, and aligned with corresponding sequences available in GenBank. All 16S rDNA sequences (1623 bp) amplified from the Taiwanese isolates were identical and had very high similarity (99.4-100%) with previously reported E. canis sequences. Nevertheless, most of the gp19 gene sequences (414 bp) from the Taiwanese isolates had three specific nucleotide substitutions at positions 9, 323 and 371 that resulted in three amino acid changes. The gp36 gene of the Taiwanese isolates consists of three regions: a 5' end pre-repeat region (426 bp), a tandem repeat region with variable numbers of the 27-bp repeat unit depending on the isolate, and a 3' end region (87 bp). The nucleotide sequences of the 5' end region of gp36 from Taiwanese isolates were identical to each other, but unexpectedly, quite distinct from the sequences of eleven other E. canis strains previously published, with 86.7-87.2% identities only. A phylogenetic tree of E. canis strains based on the gp36 amino acid sequences showed that the Taiwanese isolates fell into a separate clade, indicating the presence of a novel strain that had not yet been characterized.

Medical waste production at hospitals and associated factors

This study was conducted to evaluate the quantities of medical waste generated and the factors associated with the generation rate at medical establishments in Taiwan. Data on medical waste generation at 150 health care establishments were collected for analysis in 2003. General medical waste and infectious waste production at these establishments were examined statistically with the potential associated factors. These factors included the types of hospital and clinic, reimbursement payment by National Health Insurance, total number of beds, bed occupancy, number of infectious disease beds and outpatients per day. The average waste generation rates ranged from 2.41 to 3.26kg/bed/day for general medical wastes, and 0.19-0.88kg/bed/day for infectious wastes. The total average quantity of infectious wastes generated was the highest from medical centers, or 3.8 times higher than that from regional hospitals (267.8 vs. 70.3Tons/yr). The multivariate regression analysis was able to explain 92% of infectious wastes and 64% of general medical wastes, with the amount of insurance reimbursement and number of beds as significant prediction factors. This study suggests that large hospitals are the major source of medical waste in Taiwan. The fractions of medical waste treated as infectious at all levels of healthcare establishments are much greater than that recommended by the USCDC guidelines.

Molecular determination of the origin of acephalic cysticercus

Acephalic cysticercus (Ac), a rarely developed multilobulated and nonencysted form of larvalTaenia, causes hydrocephalus or adhesive arachnoiditis in the ventricles and subarachnoidal space that often lead to fatal outcome in affected patients. Ac has been proposed to originate fromT. soliumon the basis of morphological features, while no molecular data supporting the presumption have been available. In the present study, we investigated the immunological properties as well as molecular characteristics of Ac that was obtained surgically from 6 patients. Immunoblotting of the cyst fluid from Ac samples demonstrated the constitutive expression of aT. soliummetacestode (TsM) 10 kDa protein. Specific antibodies against the truncated 10 kDa protein, which appears to be species specific for TsM cysticercosis, were detected in both serum and cerebrospinal fluid samples of Ac patients. Nucleotide sequences of mitochondrial cytochromecoxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1) genes of Ac were almost identical to those ofT. soliumbut differed substantially from those of the otherTaeniaspecies. In phylogenetic analysis, Ac clustered withT. soliumin a well-supported clade. Our results strongly suggest that Ac may have originated fromT. solium.

Boron-lipiodol: a potential new drug for the treatment of liver tumors

BACKGROUND

Boron neutron capture therapy (BNCT) is a form of radiation therapy and has been proposed for the treatment of some malignancies with encouraging results. However, none of them has ever been applied to liver malignancy. The purpose of this study was to evaluate the potential of boron-lipiodol (B-lipiodol) for the treatment of VX2 liver tumor via BNCT.

MATERIALS AND METHODS

Twelve New Zealand rabbits were randomly separated into two groups: lipiodol and boron-lipiodol groups. The rabbits were anesthetized, a midline incision was made and the left lobe of the liver was injected with 0.1 ml of VX2 tumor cells. After the tumor reached 2-3 cm in diameter, the rabbits were anesthetized and 0.5 ml of boron-lipiodol was injected into the hepatic artery via an angiocatheter. Liver function tests and renal function tests were performed before, at 12 hours, 24 hours, 48 hours and 7 days after injection of drugs in both groups. The concentration of boron in various tissues was determined on the 7th day after injection.

RESULTS

Liver function was abnormal at 12 hours after injection, and then gradually returned to normal at 7 days, indicative of acute temporary hepatic damage. As for the renal function, no significant change was noted in either group. The boron level was 49.7 ppm in tumor and 6.31 ppm in the healthy liver 7 days after injection of B-lipiodol. The ratio of boron concentrations between the tumor and the normal liver tissue was 7.87. As for blood and other organs including spleen, heart and kidney, the concentration of boron was low. In the lipiodol group, the boron concentrations in tumor and various organs were low.

CONCLUSION

The high concentration of boron after intra-arterial injection of B-lipiodol can be used for neutron capture therapy. B-lipiodol has potential for the treatment of liver malignancy.

Antioxidant effect of melatonin in human retinal neuron cultures

This study investigates whether the neurohormone melatonin can prevent the retinal neuronal injury caused by reactive oxygen species (ROS) in cultured human retinal neuronal cells. Cultures of human retinal neuronal cells established from a variety of donors were grown to 14 days and then subjected to experimental hypoxanthine/xanthine oxidase (HX/XO)-induced injury. Intracellular production of ROS by administration of HX/XO was confirmed by flow cytometry; the ROS resulted in both apoptotic and necrotic pattern of cell death in the retinal neuron cultures. The efficacy of melatonin against ROS injury was quantitated by MTT assay, enzyme immunoassay, and immunocytochemistry for neurofilament protein. The antioxidative effect of melatonin was compared with that of alpha-tocopherol. Retinal neuronal injury significantly reduced in a dose-response manner by a treatment of 1.0-8.0 mM alpha-tocopherol. Melatonin, in concentrations of more than 2.0 mM, also significantly reduced the injury. About 70% of cells are rescued by pretreatment with 1.0 mM alpha-tocopherol and 8.0 mM melatonin in the MTT assay. Our observations suggest that melatonin can rescue retinal neurons from ROS injury in human retinal cell cultures.

The water extract of Samultang protects the lipopolysaccharide (LPS)/phorbol 12-myristate 13-acetate (PMA)-induced damage and nitric oxide production of C6 glial cells via down-regulation of NF-kappaB

Samultang has been traditionally used for treatment of ischemic heart and brain diseases in oriental medicine. However, little is known about the mechanism by which Samultang rescues the myocardial and neuronal cells from ischemic damage. This study was designed to evaluate whether the water extract of Samultang may modulate the production of nitric oxide (NO) in LPS and PMA treated-C6 glial cells to protect the cells from NO-induced cytotoxicity. C6 glial cells treated with both LPS and PMA significantly produced a large amount of NO compared to untreated, PMA, or LPS-treated cells. In parallel with NO production, cotreatment of LPS and PMA induced the severe apoptotic death of C6 glial cells. However, Samultang significantly reduced both cell death and NO production by LPS/PMA in a dose-dependent manner. In addition, the modulatory effects of Samultang on LPS/PMA-induced cytotoxicity and NO production could be mimicked by exogenous treatments of N(G)MMA, a nitric oxide synthase (NOS) inhibitor, and pyrrolidine dithiocarbamate (PDTC), a strong NF-kappaB inhibitor. Treatment of C6-glial cells with LPS/PMA induced the transcriptional activation of NF-kappaB, which was markedly inhibited by Samultang. Taken together, we suggest that the protective effects of Samultang against LPS/PMA-induced cytotoxicity may be mediated by the suppression of NO synthesis via down-regulation of NF-kappaB activation.

Sodium nitroprusside induces apoptosis of H9C2 cardiac muscle cells in a c-Jun N-terminal kinase-dependent manner

Sodium nitroprusside (SNP) induces apoptosis in H9C2 cardiac muscle cells. Treatment with an exogenous NO donor SNP (2 mM) to H9C2 cells resulted in apoptotic morphological changes; a bright blue-fluorescent condensed nuclei and chromatin fragmentation by fluorescence microscope of Hoechst 33258-staining. The activity of caspase-3 like protease was increased during SNP-induced cell death. However, the activity of caspase-1 like protease was not affected by SNP. Pretreatment with Z-VAD-FMK (a pan-caspase inhibitor) or Ac-DEVD-CHO (a specific caspase-3 inhibitor) abrogated the SNP-induced cell death. SNP markedly activated three MAP kinases (JNK/SAPK, ERK and p38 MAP kinase) in the cardiac muscle cells. In this study, selective inhibition of the ERK or p38 MAPK pathway (by PD98059 or SB203580, respectively) had no effect on the extent of SNP-induced apoptosis in cardiac muscle cells. In contrast, inhibition of the JNK pathway by transfection of a dominant negative mutant of JNK markedly reduced the extent of SNP-induced cell death. Taken together, we suggest that JNK/SAPK will be related to SNP-induced apoptosis of H9C2 cardiac muscle cells.

Protective effects of morphine in peroxynitrite-induced apoptosis of primary rat neonatal astrocytes: potential involvement of G protein and phosphatidylinositol 3-kinase (PI3 kinase)

Opiates, such as morphine, have been used extensively in the clinical management of pain due to their potent analgesic effect. Astrocytes, representing a major non-neuronal cell population in the CNS, contain opioid receptors that are actively involved in several brain functions. This study was designed to evaluate the effects by which morphine, a preferential mu-opioid receptor agonist, contributes to cytotoxicity of nitric oxide (NO) species, including NO and peroxynitrite (ONOO-), in primary rat neonatal astrocytes. Primary astrocytes isolated from the cerebral cortex of 1- to 2-day-old Sprague-Dawley rats were treated with morphine, naloxone, and 3-morpholinosydnonimine (SIN-1), a donor of peroxynitrite. Morphine significantly protected primary rat astrocytes from apoptosis mediated by sodium nitroprusside, an NO donor, and SIN-1 in a dose-dependent manner, whereas it did not in other types of cells including C6 glioma, RAW 264.7, and HL-60 cells. Moreover, naloxone antagonized the protective effects of morphine on SIN-1-induced apoptosis. Morphine also inhibited the nuclear condensation and fragmentation of SIN-1-treated cells that was antagonized by naloxone pretreatment. The protective role of morphine in SIN-1-induced apoptosis was dependent on an intracellular antioxidant system such as GSH. Furthermore, the effects of morphine on SIN-1-induced cytotoxicity were prohibited by pretreatment with the G(i) protein inhibitor, pertussis toxin, and the phosphatidylinositol 3-kinase (PI3 kinase) inhibitors, wortmannin and LY294002. Taken together, these results suggest that morphine may protect primary rat astrocytes from apoptosis by NO species via the signaling cascades that involve both G protein and PI3 kinase.

Effectiveness and safety of rocuronium-hypnotic sequence for rapid-sequence induction

BACKGROUND

Either succinylcholine or rocuronium administered after a hypnotic is the current technique for rapid-sequence induction. It is assumed that rocuronium administered before a hypnotic (Rocuronium-hypnotic sequence) may equally provide an acceptable intubation condition as well as a shorter period of apnea in rapid-sequence induction. We designed a prospective, randomized study to evaluate the effectiveness and safety of the technique in a similar rapid-sequence induction.

METHODS

Ninety adult patients receiving elective surgeries were enrolled in this study. In all patients the procedure in the study began with i.v. injection of fentanyl 2 micrograms/kg, followed by preoxygenation with 100% O2 for 2 min. Afterward, the patients were randomly allocated to 3 groups with each group consisting of 30 patients. In Rocuronium-thiopental (Ro-Th) group the patients received rocuronium 0.6 mg/kg and then thiopental 5 mg/kg; in Th-Ro group the patients received thiopental 5 mg/kg and then rocuronium 0.6 mg/kg; and in Thiopental-Succinylcholine (Th-Sx) group, the control group, the patients received thiopental 5 mg/kg and then succinylcholine 1 mg/kg. Laryngoscopy and endotracheal intubation were performed 60 s after the injection of the muscle relaxant. The intubation condition, the apneal time before laryngoscopy, the intubation time, and total apneal time were investigated and compared. Presence of injection pain, sense of paralysis, SpO2 less than 95% during induction, and any unexpected adverse event were also recorded.

RESULTS

Six patients (1 in Ro-Th group, 2 in Th-Ro group, and 3 in Th-Sx group, respectively) were excluded from the study. The intubation conditions were acceptable in all patients of three groups who completed the study, and as to excellent intubation condition there was no difference between the three groups. In Ro-Th group both the apneal time before laryngoscopy (32.4 +/- 5.4 s) and total apneal time (48.5 +/- 11.0 s) were the shortest. Th-Ro group (53.2 +/- 5.8 and 67.5 +/- 8.3 s, respectively) and Th-Sx group (54.4 +/- 5.8 and 68.4 +/- 7.7 s, respectively) were similar in both aspects. With respect to intubation time there was no significant difference among the three groups. Five patients in Ro-Th group and one patient in Th-Sx group felt mild injection pain. Three patients in Ro-Th group were noted to have diminished breathing during induction, which was not recalled during enquiry in the postoperative visit. One patient in Ro-Th group saw a fall of SpO2 down below 95% (94% the minimal) during the apnea period.

CONCLUSIONS

Compared with traditional hypnotic-rocuronium or hypnotic-succinylcholine sequence, rocuronium (0.6 mg)-thiopental sequence can provide a similar intubation condition but cause a much shorter apneal period in rapid-sequence induction. In carrying out recuronium-thiopental sequence induction, maintaining a patent infusion line is essential to avoid drug precipitation and awareness of muscular weakness as a result of ill-timed action of thiopental.

Human chorionic gonadotropin induces nitric oxide synthesis by murine microglia

This study investigated the effects of human chorionic gonadotropin (hCG) on the synthesis of nitric oxide (NO) in murine neonatal microglial cells. When hCG was used in combination with interferon-gamma (IFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as an increased amount of iNOS protein. The increase of NO synthesis by IFN-gamma-plus-hCG was associated with the increase of tumor necrosis factor-alpha (TNF-alpha) secretion and hCG-induced NO production was decreased by the treatment with anti-murine TNF-alpha neutralizing antibody. This study provides evidence that hCG activates expression of iNOS protein in murine microglial cells accompanied by NO accumulation via pathway dependent on L-arginine in the culture medium, and further offers that TNF-alpha acts on the NO synthesis from IFN-gamma-primed murine microglial cells.

The water extract of Jagamchotang protects the ischemia/reperfusion-induced cytotoxicity of rat neonatal myocardial cells via generation of nitric oxide

Jagamchotang has been used for treatment of ischemic myocardial diseases in Chinese traditional medicine. However, little is known about the mechanism by which Jagamchotang rescues myocardial cells from ischemic damages. To elucidate the protective mechanisms, the effects of Jagamchotang on ischemia/reperfusion-induced cytotoxicity and generation of nitric oxide (NO) are investigated in primary neonatal myocardial cells. Ischemia/reperfusion itself induces severe myocardial cell death in vitro. However, treatment of the cells with Jagamchotang significantly reduces both ischemia/reperfusion-induced myocardial cell death and LDH release. In addition, pretreatment of Jagamchotang before reperfusion recovers the lose of beating rates after ischemia/reperfusion. For a while, the water extract of Jagamchotang stimulates myocardial cells in ischemic condition to produce nitric oxide (NO) in a dose dependent manner and it protects the damage of myocardial cells. Furthermore, the protective effects of the water extract of Jagamchotang is mimicked by treatment of sodium nitroprusside, an exogenous NO donor. NG-monomethyi-L-argine (NGMMA), a specific inhibitor of nitric oxide synthase (NOS), significantly blocks the protective effects of Jagamchotang on the cells after ischemia/reperfusion. Taken together, we suggest that the protective effects of Jagamchotang against ischemia/reperfusion-induced myocardial damages may be mediated by NO production during ischemic condition.

Expression of 3 beta-hydroxysteroid/dehydrogenase/delta5-delta4/isomerase in the tracheal cartilage of the rat

The enzyme complex 3beta-hydroxysteroid dehydrogenase isomerase/delta5-delta4 (3beta-HSD) is involved in the biosynthesis of all classes of active steroids. In this study, the presence of 3beta-HSD was defined in rat tracheal cartilage. The expression of the 3beta-HSD gene was examined by Northern blot analysis from 30-day-old rats. Western blot and immunohistochemical localization were also performed with antibodies raised against purified human placental 3beta-HSD to obtain further information on the expression of 3beta-HSD protein during fetal and postnatal periods of development in rat cartilage. Northern blot analysis using an oligonucleotide common to the 4 known 3beta-HSD isoforms showed 3beta-HSD mRNA corresponding to a transcript of 1.7 kb. Furthermore, a 42 KDa protein band was detected in the tracheal cartilage extracts by Western blot analysis. Immunostaining for 3beta-SD was observed in chondrocytes. The first expression was detected on the 17th day of fetal life by Western blot and immunohistochemistry. Immunoreactivity of 3beta-HSD showed a significant increase at 7 and 15 days after birth, and then remained unchanged through adulthood, in agreement with the data of the Western blot. Our results demonstrated the expression for 3beta-HSD in the tracheal cartilage at both the mRNA and protein levels during fetal life and postnatal development of the rat. These results suggest that 3beta-HSD may synthesize certain steroids which play major roles in differentiation and maintenance of function during development of rat cartilage.

Expression of protein kinase C genes in normal (+/+) and W mutant alleles (Wsh/Wsh, W/Wv) mice testes

In the present study, we investigated the expression of mRNA of protein kinase C (PKC) isoenzymes (alpha, beta, gamma, delta, epsilon, zeta, eta, and theta) in normal (+/+) and W mutant alleles mice testes. In +/+ mice testes, abundant expression of PKCdelta and PKCtheta was observed, while other PKCs (alpha, beta, gamma, epsilon, zeta, and eta) generally were not detected by Northern blotting. The PKCdelta and PKCtheta isoenzymes demonstrated a distinctive cellular distribution when evaluated by in situ hybridization. We have previously shown that PKCdelta gene was selectively expressed in spermatid of +/+ testes. Here we show that PKCdelta gene is also present in spermatid of Wsh/Wsh mice testes and PKCtheta gene was present in interstitial cells of +/+, Wsh/Wsh, and W/Wv mice testes. These studies provide the evidence of selective cell distributions of the PKC isoenzymes and suggest that PKC has the functional significance in testes.

Prenatal detection of de novo inversion of chromosome 9 with duplicated heterochromatic region and postnatal follow-up

We report the first de novo case of a heterochromatic duplication on the long arm of the chromosome 9, which then was pericentrically inverted at p11q13. This condition was detected prenatally and carry to term. We then performed the follow up for over 1 year. So far, there seems to be no phenotypical abnormalities.

Acute jaundice in pregnancy: acute fatty liver or acute viral hepatitis?

In this case, the difficulty in differential diagnosis between acute viral hepatitis and acute fatty liver of pregnancy was analyzed. These 2 conditions often raise controversal question regarding the decision making on emergency anesthesia for cesarean section to avert complications and optimize management. The dilemma in which an anesthesiologist is put is whether to promise the anesthesia straightaway in the face of a demonstrable acute jaundice in pregnancy to advise a postponement of surgery until a turn for the better. In this embarrassing situation, the authors suggest that a postpronement of surgery is rational to observe the development during which both the mother and the fetus should be closely monitored. Once the necessity of a cesarean section outweighs the benefit of transitional conservative treatment, it should be performed immediately.

Interleukin-3 or immunoglobulin E promotes expression of protein kinase C delta gene in murine mast cells

We reported previously that protein kinase C delta (PKCdelta) is the main isoenzyme in various types of murine mast cells. In the present study we investigated the regulation of expression of PKCdelta gene in murine mast cells in vitro and in vivo. The mRNA expressions of PKCdelta were promoted in response to interleukin-3 (IL-3) or immunoglobulin E (IgE) in mouse mastocytoma P-815 cells. In addition we have evaluated the mast cells which express PKCdelta mRNA in IgE-dependent passive cutaneous anaphylaxis reaction, using in situ hybridization with the antisense riboprobe in skin. These results indicate that mast cell activation can induce a marked promotion in steady state levels of PKCdelta mRNA.

An alternative continuous caudal block with caudad catheterization via lower lumbar interspace in adult patients

BACKGROUND

Continuous caudal block with caudad catheterization has not yet been mentioned in literatures. We designed a preliminary study to investigate the feasibleness of this technique, spread of contrast medium under fluoroscopy, and its clinical effectiveness.

METHODS

Ten patients were subjected to epidural block (caudal) for elective anal or vaginal procedures. The entry of the epidural needle was made at the L4-5 interspace either with midline or paramedian approach. Through an 18 G Touhy needle with its bevel facing caudally an epidural catheter was threaded until a length of 10 cm was beyond the point of entry. The presence or absence of paresthesia during the passage of catheter and the ease with which the catheter was inserted were recorded. After the procedure, the course on which the catheter traversed and the spread of the medicinal substance in the epidural space were visualized and studied fluoroscopically using 1 and 3 ml iohexol (omnipaque 300 mg/ml) as contrast medium respectively. Then the patients were brought to operating rooms for anesthesia and surgery. Sensory anesthetic level and motor blockade were evaluated fifteen min after 11-15 ml of 2% lidocaine had been injected through the epidural catheter. During anesthesia vital signs were closely monitored, and adverse reaction if any was evaluated and managed.

RESULTS

The insertion of the epidural catheter was considered easy and caused no paresthesia in nine patients. Catheter insertion encountered moderate resistance and induced paresthesia in one patient. Yet, the catheter was advanced successfully to the expected length. In radiological study with contrast medium, the course of the epidural catheter was not always traceable, while the spread of the contrast medium was clearly identified. Epidural spread occurred in eight patients, left paravertebral spread in one patient, and right retrorectal spread in another one patient. As to clinical assessment, adequate sensory blockade with local anesthetic was gained in 8 patients with well-preserved motor function of the lower limbs. In one patient the caudal block worked well after the withdrawal of the catheter 5 cm in length. Spinal anesthesia was supplemented in one patient due to failure of the caudal block.

CONCLUSIONS

Continuous caudal block with caudawise catheterization via lower lumbar interspaces is feasible (eight of 10 patients in this study) with respect to technique and clinical effect. Paravertebral and retrorectal migrations of the catheter may occur in spite of smooth catheterization. Either migration might lead to a failure of caudal block.

Immunohistochemical study of 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase in the rat cardiovascular system

The enzyme complex 3beta-hydroxysteroid dehydrogenase (3beta-HSD) is involved in the biosynthesis of all classes of active steroids. It is known that the enzymatic activity of 3beta-HSD is present not only in classical steroidogenic tissues, but also in many peripheral tissues including cardiac tissue. To determine whether 3beta-HSD is present in rat non-steroidogenic tissues, we examined cardiovascular tissues including the ventricle, atrium, aortic arch, abdominal aorta, and inferior vena cava by immunohistochemistry and Western blotting using polyclonal antibody raised against a synthetic peptide of human placental 3beta-HSD. By Western blotting, protein bands immunoreactive for anti-3beta-HSD were detected at molecular weights of 42 and 37 kDa in both the ventricle and atrium, whereas only a 37 kDa band was recognized in both the aortic arch and abdominal aorta. By immunohistochemistry, immunoreactivity for 3beta,-HSD was detected in both the ventricular and atrial cardiocytes, while immunostaining was also found, though faintly, in the smooth muscles of the aortic arch, abdominal aorta, and inferior vena cava. These results suggest that cardiocytes may synthesize the steroidogenic 3beta,-HSD enzyme.

Intracerebral hemorrhage in a young woman with arteriovenous malformation after taking diet control pills containing phenylpropanolamine: a case report

Administration of phenylpropanolamine (PPA) is a rare cause of intracerebral hemorrhage. We present the case of a young female patient with arteriovenous malformation who suffered an intracerebral hemorrhage after ingestion of diet pills containing PPA. The literature on PPA-related intracerebral hemorrhage is also reviewed. This is the first report of PPA-associated intracerebral hemorrhage in a patient with pathology-proven arteriovenous malformation of the brain. Because intracerebral hemorrhage may develop as a side effect of PPA when patients take the manufacturer's recommended dose, especially in patients with vascular abnormalities, we conclude that this medicine should be prescribed carefully and patients should be closely monitored by experienced physicians. Furthermore, its use should be contraindicated in patients who have, or possibly have, a family history of vascular abnormalities.

Functional expression of the bovine herpesvirus 1 alkaline deoxyribonuclease (UL12) in Escherichia coli

Sequence analysis within the unique long segment of the bovine herpesvirus 1 (BHV-1; infectious bovine rhinotracheitis virus) genome identified an open reading frame whose deduced protein product of 487 amino acids exhibited homology to alkaline deoxyribonucleases (DNases) of other herpesviruses. To determine this BHV-1 gene product has nuclease activity, the gene designated UL12 was inserted into the vector pET-28a(+) and expressed in Escherichia coli as an oligohistidine-tagged protein. Upon induction with isopropyl beta-D-thiogalactopyranoside E. coli BL21 (DE3) [pLysS] cells carrying this recombinant plasmid produced a 57-kDa protein, the molecular mass of which was in accordance with the prediction from the DNA sequence. The recombinant UL12 protein purified by nickel-chelating affinity chromatography exhibited both exonuclease and endonuclease activity, each with an alkaline pH optimum.

Dioxin contents in fly ashes of MSW incineration in Taiwan

Fly ashes from three municipal solid waste (MSW) incinerators in Taiwan were collected and segregated into different fractions for determining the physical and chemical properties and dioxin contents. Analysis of ashes with each fraction indicated that fine particles had higher dioxin contents than large particles. Dioxin homologue components of ashes generated from large-scale mass burn MSW incinerator were less toxic than that from small-scale batch incinerators, and contained less non-2,3,7,8 PCDD/Fs. Correlation analysis did not reveal a consistent trend between dioxins content and ashes' physical properties, while strong positive correlation was found between dioxins content and chloride content. Positive correlation between dioxin content and heavy metals content such as copper and zinc in the fly ash was also established.

The peripheral analgesic effect of meperidine in reducing propofol injection pain is not naloxone-reversible

BACKGROUND AND OBJECTIVES

Meperidine is frequently used in general anesthesia and perioperative analgesia. In addition to its opioid action, meperidine possesses some local anesthetic properties. A preliminary study using the tourniquet venous retention technique found meperidine to be more effective in reducing propofol injection pain than fentanyl or morphine, both of which were slightly better than placebo. This study was undertaken to evaluate whether this peripheral analgesic effect of meperidine is affected by naloxone.

METHODS

In a randomized, double-blind manner, after venous occlusion with a tourniquet, meperidine 40 mg was given intravenously to patients in group A (n = 31), meperidine 40 mg followed by naloxone 0.04 mg to group B (n = 32), meperidine 40 mg followed by naloxone 0.2 mg to group C (n = 30), and normal saline placebo to group D (n = 30). The venous retention of drug(s) was maintained for 1 minute, followed by tourniquet release and intravenous administration of propofol 100 mg. Pain assessment was made immediately after the propofol injection.

RESULTS

All three groups given meperidine had significantly less propofol injection pain (P < .01 ) than the group given saline placebo, and there was no difference among groups A, B, and C.

CONCLUSION

The peripheral analgesic effect of meperidine in reducing propofol injection pain is not mediated by its opioid activity.

Comparison of intravenous retention of fentanyl and lidocaine on local analgesia in propofol injection pain

BACKGROUND

With a tourniquet on arm for arresting venous blood flow, we evaluated the efficacy of intravenous (i.v.) retention of fentanyl and lidocaine in reducing the pain on i.v. propofol injection during general anesthesia.

METHODS

One hundred and twelve patients were studied. Following a venous occlusion by a tourniquet inflated to 70 mmHg, patients in Group A (n = 38) received normal saline (NS) 3 ml, while those in Group B (n = 37) and in Group C (n = 37) respectively received fentanyl 150 micrograms or 3 ml and 2% lidocaine 3 ml (60 mg). The venous retention of drug was maintained for 1 min, followed immediately by tourniquet release and propofol 100 mg i.v. injection over 20 s.

RESULTS

Both fentanyl and lidocaine treatments (Groups B and C) were significantly better than placebo (Group A) in reducing pain on propofol injection (p < 0.005). Lidocaine 60 mg was more effective than fentanyl 150 micrograms in reduction of pain associated with i.v. propofol (p < 0.001). Injection of fentanyl itself caused pain in 28% of patients as compared to 2% in the lidocaine group. Mild local skin erythema was noted in 14% of patients with fentanyl venous retention versus 0% of patients with lidocaine venous retention.

CONCLUSIONS

Intravenous retention of fentanyl 150 micrograms, although less effective than that of lidocaine (p < 0.001), showed local analgesic effect in reducing the pain on propofol injection. The hypothetic mechanisms of action were speculated.

Purification of the infectious bovine rhinotracheitis virus alkaline deoxyribonuclease expressed in Escherichia coli

Nucleotide sequence analysis within the unique long segment of the infectious bovine rhinotracheitis virus (IBRV) genome identified an open reading frame of 1461 base pairs whose deduced polypeptide of 487 amino acids exhibited homology to alkaline deoxyribonucleases of other herpesviruses. To determine whether this IBRV gene product has nuclease activity, the gene designated UL12 was inserted into the vector pET-28a(+) and expressed in Escherichia coli as an oligohistidine-tagged protein. Upon induction with isopropyl beta-D-thiogalactopyranoside E. coli BL21 (DE3)[pLysS] cells harboring this recombinant plasmid produced a 57-kDa protein, the molecular mass of which was in accordance with the prediction from the nucleotide sequence. A one-step purification procedure using metal affinity chromatography resulted in a homogeneous preparation of this recombinant protein. The purified protein exhibited both exonuclease and endonuclease activities, each with an alkaline pH optimum.

The UL2 open reading frame of bovine herpesvirus 1 encodes a uracil-DNA glycosylase

Sequence analysis within the unique long segment of the bovine herpesvirus 1 (BHV-1) genome previously identified an open reading frame (ORF), designated UL2, whose deduced polypeptide of 204 amino acids contained a consensus uracil-DNA glycosylase (UDGase) signature sequence. To determine whether the BHV-1 UL2 ORF product has UDGase activity, we positioned the UL2 sequence down-stream of the T7 promoter on the vector pET-28b(+) and expressed it in Escherichia coli. Upon induction with isopropyl beta-D-thiogalactopyranoside these cells produced a 23-kDa protein, the molecular mass of which was in accordance with the prediction from the nucleotide sequence. A one-step purification procedure using nickel-chelating affinity chromatography resulted in a homogeneous preparation of this protein, which displayed specific UDGase activity in an in vitro enzyme assay. These results provide evidence that the BHV-1 UL2 gene does encode a UDGase.

Endothelial F-actin changes in the alkali burned rabbit cornea

The healing mechanism of corneal endothelium after alkali burn was not completely understood. Rabbit cornea was burned with 1N sodium hydxoside for 1 minute. Endothelial F-actin was stained with NBD-phallacidin in regular sequence to find out the details of endothelial healing after alkali burn. F-actin was completely destroyed leaving a sharp margin against the unaffected area 1 hour after the burn. In the 3, 5 and 7 day specimens, highly active F-actin reactions were noted at the wound margin. New multiple F-actin layers, arising from the intact endothelium near the wound margin, were noted in the 9 day specimen. In the 8 1/2 month specimen, the endothelial defected area was covered by large primitive cells, each of which showed F-actin fiber bundles in the cytoplasm with a large nuclear shadow. Nearly all of the large primitive cells showed F-actin fibers arranged in shapes of cell junctions. Twelve months after the burn, endothelial defects were not found. Nearly all of the endothelial cells were normal in size and shape except for some mushroom-like projections toward the anterior chamber in some areas. Nineteen months after the burn, the endothelial cells were normal. Endothelial wound healing process can be continued even 1 year after the alkali burn in rabbit cornea.

Soluble interleukin-2 receptor and cellular profiles in bronchoalveolar lavage fluid from patients with bronchial asthma

BACKGROUND

To elucidate the role of T-cell activation in the physiologic changes and cellular infiltrations in the bronchial tree of patients with symptomatic bronchial asthma, we measured the concentration of soluble interleukin-2 receptor (sIL-2R), cellular compositions and IL-2R expression on cells in bronchoalveolar lavage (BAL) fluid. We also measured physiologic parameters, including a provocation concentration of histamine required to reduce the forced expiratory volume in 1 second by 20% of the prechallenge baseline (PC20).

RESULTS

The concentration of sIL-2R and the ratio of IL-2R expression on CD3 positive lymphocytes were significantly higher in BAL fluid from 20 patients with symptomatic bronchial asthma than concentrations in fluid from nine healthy controls (p < 0.01) and six asymptomatic patients with bronchial asthma (p < 0.05). The concentration of sIL-2R correlated with the percentage of IL-2R expression on CD3 positive lymphocytes (rs = 0.709, p < 0.01). There was no difference in sIL-2R concentration of BAL fluid between the healthy control and the patient with asymptomatic bronchial asthma. Among the inflammatory cells recovered in BAL fluid, the percentages of eosinophils showed significant positive correlation with the concentration of sIL-2R in BAL fluid in the patients with bronchial asthma. The concentration of sIL-2R significantly correlated with forced expiratory volume one second, peak expiratory flow rate, and PC20 when observed in all study subjects, but not in the patients with bronchial asthma.

CONCLUSION

We conclude that T-cell activation within the bronchial tree appears to have a role in the infiltration of eosinophils into the bronchial tree, which may lead to enhanced bronchial hyperreactivity in patients with bronchial asthma.

Hyperamylasemia following cardiopulmonary bypass

In order to study the occurrence of postbypass hyperamylasemia, 75 patients undergoing cardiopulmonary bypass (CPB) were studied from March 1989 to January 1990. There were 49 males and 26 females. Among them, 27 had congenital heart disease, 30 had valvular disease, and 18 had coronary artery disease. There were 27 patients with at least one elevated serum amylase sample after operation. Thus, the overall incidence of hyperamylasemia was 36%. As compared with the preoperative data (1.3%), there was a statistically significant difference in the occurrence of hyperamylasemia (p less than 0.05). Three patients had overt clinical pancreatitis postoperatively. There was no positive correlation between the serum amylase level and the occurrence of pancreatitis (p greater than 0.05). Forty-two cases had a significant elevation of the amylase creatinine clearance ratio (ACCR) after CPB. However, there was no significant difference between the groups with pulsatile and nonpulsatile CPB (p greater than 0.05). Three patients (4%) died in our series. The causes of death were heart failure in two and fulminant pancreatitis associated with low cardiac output in one. Although our experience in dealing with pancreatitis improved survival, mortality was still high (33.3%) in our series. Nevertheless, there was no apparent correlation between mortality and postbypass hyperamylasemia (p greater than 0.05). Logistic regression analysis was used to analyze the risk factors of the occurrence of hyperamylasemia, and the analysis revealed that patients with coronary artery disease were susceptible to postbypass hyperamylasemia. Our studies indicate that the use of total serum amylase or ACCR to monitor for the occurrence of pancreatitis in postbypass patients is inadequate.(ABSTRACT TRUNCATED AT 250 WORDS)

The TATA-dependent and TATA-independent promoters of the Drosophila melanogaster actin 5C-encoding gene

The major cytoskeletal actin of Drosophila melanogaster, actin 5C, is encoded by a gene (act5C) that has two promoters which are differentially controlled and possess distinct sets of regulatory elements. The distal basal promoter has a TATA motif, but the proximal does not. The distal strong positive domain, centered at nucleotide -290, can be shifted and fused directly to the distal basal promoter without losing its activity. It can also activate heterologous basal promoters containing either TATAAAT or TATTTAA signal when directly fused to them, but cannot activate the basal proximal promoter, which is TATA-less. When the entire distal regulatory region, which includes a remote enhancer-like region, is fused to the proximal promoter, it does not increase the proximal promoter activity. Fusion of the distal strong negative domain to the proximal promoter does not inhibit activity. Thus, all the three major strong regulatory domains of the distal promoter are unable to act on the proximal promoter.

Subpleural block in patients with multiple rib fractures

Multiple rib fractures result in agonizing pain as well as impaired pulmonary functions. Mechanical ventilations are frequently indicated for those with poor respiratory reserves. Regional anesthesia has been advocated for easing pain and discomfort. We evaluate the efficacy of subpleural block in the treatment of multiple rib fractures. Ten patients who sustained multiple rib fractures were observed on the arrival of emergent service. One sustained flailed chest with respiratory distress which necessitated mechanical ventilation in intensive care unit. Subpleural block with 20 ml 0.5% bupivacaine was done to each patient. The location of catheter was identified by the injection of contrast medium. Serial visual analogue pain scale, arterial blood gas, and pulmonary function test were taken before and after subpleural block. Pulmonary function test significantly improved after subpleural block. Pain relief was immediate and desirable. The case in ICU weaned from ventilator 3 days later. There were no major complications after subpleural block. Inadvertent epidural spread and recurrent laryngeal nerve blocks were detected both clinically and radiologically without sequela noted. Subpleural block is effective both in pain relief and in improving pulmonary functions. Image intensifier is essential to subpleural block in order to prevent the misplacement of catheter. We recommend subpleural block to be an alternative approach of regional anesthesia in patients with multiple rib fractures.

Positive and negative regulatory elements mediating transcription from the Drosophila melanogaster actin 5C distal promoter

The major cytoskeletal actin gene of Drosophila melanogaster, the actin 5C gene, has two promoters, the distal one of which controls synthesis of actin in a tissue- and developmental stage-specific manner. This very strong promoter has widely been used for expression of heterologous genes in cultured cells. To locate functional regulatory elements in this distal promoter, mutants of the promoter were fused to the bacterial chloramphenicol acetyltransferase gene and assayed for transient expression activity in cultured Drosophila embryonic Schneider line 2 cells. The results showed that the upstream end of the promoter extends to 522 bp from the transcription start site. In addition, there are two remote activating regions about 2 kb upstream. Between -522 and -379 are two regions that exert a strong negative effect. Downstream from these negative regions are at least six positive regions and a TATA element. The strongest positive determinant of the promoter was identified at -320 as AAAATGTG by footprinting and by a replacement experiment. When the relevant region was replaced by a synthetic sequence containing this element in a random context, the transient expression activity was restored. The sequence TGTATG located at -355 was also identified as a positive element by a similar replacement approach. Apparently the very high activity of this promoter is the result of the combined activities of multiple factors.

Regulatory elements mediating transcription from the Drosophila melanogaster actin 5C proximal promoter

The major cytoskeletal actin gene of Drosophila melanogaster, the actin 5C gene, has two promoters, the proximal one of which controls constitutive synthesis of actin in all growing tissues. To locate regulatory elements required for constitutive activity of the proximal promoter, mutants of this promoter were fused to the bacterial chloramphenicol acetyltransferase gene and assayed for transient expression activity in cultured Drosophila embryonic Schneider line 2 cells. An essential regulatory element has been located 313 base pairs upstream from the cap site. Deletion of this element lowered expression to one-third of the wild-type level. The element has the sequence AAGTTGTAGTTG, as shown by protein-binding footprinting with the reagent methidiumpropyl-EDTA-Fe(II). This element is probably not a general one, since it was not detected in a search of the published 5'-flanking sequences of 27 Drosophila genes. In addition to this regulatory element, there are five GAGA elements in the actin 5C proximal promoter, some or all of which are essential for the promoter activity as shown by an in vivo competition assay. Although this promoter has no classical TATA element, there is an essential promoter region about 35 base pairs upstream from the cap site that could be a TATA surrogate. The promoter also shows sequences homologous to the alcohol dehydrogenase factor 1-binding site and to the core of the vertebrate serum response element, but mutations of these sites did not affect promoter activity in transient expression assays.

The optimal dose of atropine via the endotracheal route

Fifty ASA class I or II patients, undergoing general or gynecological surgery under general anesthesia with endotracheal intubation, were randomly divided into five groups. Group I received 10 ug/kg atropine intravenously, group II to V received 10 ug/kg, 20 ug/kg, 30 ug/kg, 40 ug/kg, respectively via endotracheal route through an epidural catheter. All were given five manual deep breaths after the injection of atropine. The maximum increase in heart rate (MIHR) and the time to maximum heart rate (TMHR) were evaluated. There was no marked MIHR in group II. Group III had a MIHR similar to that of group I (17.5/min vs 20/min, p greater than 0.05), but had a longer TMHR than group I (120 sec vs 82.5 sec, p less than 0.005). Groups IV and V had greater MIHR than group I (28.7 and 29.5 vs 20/min, p less than 0.005), and a TMHR similar to that of group I (85 and 90.2 vs 82.5 sec, p greater than 0.05). For emergency procedures, if atropine must be given without an intravenous catheter, 30 ug/kg or more given endotracheally can achieve an effect comparable to that of 10 ug/kg given intravenously.

Squamous carcinoma of the nasopharynx

Nasopharyngeal carcinoma is an unusual neoplasm among squamous cell carcinomas of the head and neck. The tumor is rare in most parts of the world but is strikingly common in several Asian subpopulations, notably Chinese in Hong Kong and Guangdong Province. The Epstein-Barr virus is intimately related to the disease and elicits the formation of antibodies that are useful for diagnosis and follow-up study. The virus has not been conclusively shown to cause nasopharyngeal cancer, however.Histologically, nasopharyngeal carcinoma is anaplastic in 75% of cases and better differentiated in 25% of patients. All tumors are treated by high-dose irradiation to the primary site and both sides of the neck. Surgical treatment, in the neck only, is reserved for irradiation failures. The prognosis is better in patients younger than 40 years, in patients without clinical cervical nodal involvement and, unexpectedly, in patients with anaplastic tumors.

Quantitative autoradiography, electron microscopy, and granulometry of endocrine cells in the rabbit colon

A high-resolution autoradiographic study was conducted on 268 thin sections of endocrine cells in the rabbit colon following injection of (3H) L-dopa. Using quantitative autoradiography, silver-proteinate impregnation, granulometry, and statistical analysis of cell populations by the Falck procedure, three cell types were identified--EC, L; and H--as well as a single cell with distinct ultrastructural characteristics. For the first time, a fine quantitative estimation of the handling ability of amine precursor related to the cross-sectional areas of each cell type was obtained, using a Kontron Digiplan image analyzer. All cells studied showed the ability to take up the precursor. Labeling indices were 6.63, 2.15, and 2.14 for EC, L, and H, respectively. These data and silver-proteinate impregnations provide good criteria for differentiating EC from H cells despite morphological similarities. After critical analysis of granule diameters, L cells were considered to be pluripotential in secretory activity.