[Research progress on the regulation of mammalian energy metabolism by the circadian clock system and gut microbiota]

The mammalian internal circadian clock system has been evolved to adapt to the diurnal changes in the internal and external environment of the organism to regulate diverse physiological functions, such as the sleep-wake cycle and feeding rhythm, thereby coordinating the rhythmic changes of energy demand and nutrition supply in each diurnal cycle. The circadian clock regulates glucose metabolism, lipid metabolism, and hormones secretion in diverse tissues and organs, including the liver, skeletal muscle, pancreas, heart, and vessels. As a special "organ" of the host, the gut microbiota, together with the intestinal microenvironment (tissues, cells, and metabolites) in a co-evolutionary process, constitutes a micro-ecosystem and plays an important role in the process of nutrient digestion and absorption in the intestine of the host. In recent years, accumulating evidence indicates that the compositions, quantities, colonization, and functional activities of the gut microbiota exhibit significant circadian variations, which are closely related to the changes of various physiological functions under the regulation of host circadian clock system. In addition, several studies have shown that the gut microbiota can produce many important metabolites such as the short-chain fatty acids through the degradation of indigestive dietary fibers. A portion of gut microbiota-derived metabolites can regulate the circadian clock system and metabolism of the host. This article mainly discusses the interaction between the host circadian clock system and the gut microbiota, and highlights its influence on energy metabolism of the host, providing a novel clues and thought for the prevention and treatment of metabolic diseases.

XPG gene polymorphisms and glioma susceptibility: a two-centre case-control study

Background: Glioma, the most common tumour in children next to leukaemia, is difficult to treat, with a poor prognosis and high recurrence rate. Xeroderma pigmentosum group G (XPG) plays a key role in the nucleotide excision repair pathway, which may modulate individual susceptibility to developing cancer. We hypothesized links between XPG variants and glioma in children.Methods: We tested our hypothesis in a study comparing 171 glioma cases with 228 age and sex matched controls, determining XPG polymorphisms rs2094258 C > T, rs751402 C > T, rs2296147 T > C, rs1047768 T > C, rs873601 G > A by standard molecular genetic methods.Results: rs2094258 C > T was associated with a decreased glioma risk, but carrying the rs1047768 C or rs873601 A allele brought an increased risk. Subjects carrying 5 risk genotypes had a significantly increased glioma risk at an adjusted odds ratio of 1.97 (95% confidence Interval 1.26-3.08)(p = 0.003) when compared with those carrying 0-4 risk genotypes. Furthermore, children with 5 risk genotypes had a higher glioma risk when aged >60 months, were more likely to be male, and with subtypes of astrocytic tumours, and low-grade clinical stage, when compared to those with 0-4 risk genotypes. Preliminary functional exploration suggested that rs2094258 is linked with the expression of its surrounding genes in the expression quantitative trait locus analysis.Conclusion: Certain variants of XPG are risk factors for paediatric glioma, and so may be useful in early diagnosis.

[Diagnosis and therapeutic strategies for non-obese type of non-alcoholic fatty liver diseases]

Non-alcoholic fatty liver disease and obesity have interconnected genes, but it can also occur in non-obese population with body mass index < 25 kg/m(2). Non-obese type of non-alcoholic fatty liver disease mostly occurs in Asia. There is no significant difference between obese and non-obese type of non-alcoholic fatty liver in histological examination of liver biopsies. Visceral obesity, high fructose and cholesterol intake, and genetic factors such as APOC3 gene mutation are closely related to non-obese type of non-alcoholic fatty liver. Generally speaking, non-alcoholic steatohepatitis has an increased mortality rate, mainly due to cardiovascular causes, and has no link with other metabolic factors. Although data on the impact of mortality from non-obese type of non-alcoholic fatty liver disease are incomplete and limited, however diagnosis, management, and treatment may be important. Lifestyle changes to reduce visceral obesity, including dietary changes and physical activity, remain the main treatment options for patients with non-obese type of non-alcoholic fatty liver disease.

[Treatment of postprandial discomfort syndrome in the elderly: a multi-centered prospective randomized controlled clinical study]

Objective: To evaluate the efficacy and safety of Oryz-Aspergillus enzyme and pancreatin tablets (Combizym(®)) in the treatment of postprandial distress syndrome (PDS) in the elderly, compared with gastrointestinal motility drugs. Methods: A prospective randomized controlled trial was designed and registered in the China Clinical Trials Registry (ChiCTR-IPR-16008185). The elderly patients with PDS were randomly divided into three groups, including Mosapride group with Mosapride citrate tablets 5 mg 3 times per day for 2 weeks; Combizym(®) group with Combizym tablets 244 mg 3 times per day for 2 weeks; combined treatment group with both drugs and same doses for 2 weeks. The modified Nepean dyspepsia index (NDSI) score, discomfort intensity score and PDS score were calculated on patients before treatment, at the end of first and second week of treatment, as well as 4 weeks after treatment finished, respectively. Adverse effects were evaluated. Results: A total of 323 patients from 16 tertiary hospitals in China were enrolled in this study. Among them, 105 patients were in Mosapride group, 109 in Combizym(®) group and 109 in combined treatment group. There were 148 males (45.8%) and 175 females (54.2%) with median age 71.4±9.0 years (60-100 years). Baseline characteristics of three groups were comparable. After treatment, the NDSI scores in three groups all decreased significantly (P<0.001), while they were similar between groups (P>0.05). The discomfort intensity score and PDS score in three groups showed a significant reduction after treatment (P<0.001), especially in the combined treatment group. Compared with Mosapride group, the scores in Combizym(®) group decreased significantly after one or two weeks [discomfort intensity score: after one week, 4.0(2.5, 8.0) vs. 6.0(3.0, 10.0); after two weeks, 3.0(0.0, 5.0) vs. 4.0(2.0, 6.0); all P<0.05. PDS score: after one week, 6.0(3.0, 9.0) vs. 7.0(3.5, 10.5); after two weeks, 3.0(0.0, 5.0) vs. 4.0(2.0, 7.0); all P<0.05]. The efficacy rate in all patients after first week of treatment was over 15.0%. The efficacy rates after two weeks were 55.2%, 68.8% and 73.4% in Mosapride group, Combizym(®) group and combined treatment group, respectively. After two week treatment, the efficacy rates in Combizym(®) group (P=0.041) and combined group (P=0.006) were higher than that of Mosapride group. The recurrence rate of Mosapride group was 9.5%, which was significantly higher than that of Combizym(®) group (1.8%, P<0.05) and combined treatment group (1.8%, P<0.05). There were no serious adverse effects in the three groups. Conclusions: The efficacy of Oryz-Aspergillus enzyme and pancreatin tablets is comparable with that of Mosapride in elderly PDS patients, with fewer adverse effects and low recurrence rate. Combination regimen indicates better efficacy than that of Oryz-Aspergillus enzyme and pancreatin tablets or Mosapride alone.

[Analysis of labor progression characteristics of 1 089 nulliparas managed by the new partogram]

Objective: To analyze labor progression characteristics among nulliparas and provide reference to labor progress management. Methods: A retrospective study was conducted on 1 089 women who went for vaginal delivery at the First Affiliated Hospital, Sun Yet-San University from January 1st, 2015 to May 31th, 2016. The duration of cervical dilation from 1.0 cm to the next and the process of initial cervical dilation (2.0 cm or 3.0 cm) to full cervical dilation of nulliparas were analyzed. Results: The cervical dilation speed was accelerating with the progress of labor. The rate of cervical dilation changed fastest between 5.0-6.0 cm dilation, which was more than 3.0 cm/hour. With regard to labor curves, at admission of 2.0 cm cervical dilation, it rose dramatically from 5.0 cm dilation. At admission of 3.0 cm dilation, it presented approximately linear rising before 5.5 cm dilation, then became steeper. Conclusions: The cervical dilation speed is fast. Both labor curves of initial cervical dilation (2.0 cm or 3.0 cm) to full cervical dilation show obvious acceleration stage with steep slope.

Clinical significance of expression of Jagged 2 in colon cancer

AIM

To detect the expression of Jagged 2 in human colon carcinoma and to analyze its clinical significance.

METHODS

The expression of Jagged 2 mRNA and protein in 42 cases of human colon carcinoma and adjacent non-tumorous tissues was detected by real-time quantitative PCR, immunohistochemistry, and Western blot. The relationship between Jagged 2 expression and clinicopathologic characteristics of colon carcinoma was then analyzed.

RESULTS

Jagged 2 mRNA and protein can be detected in colon carcinoma tissues and adjacent non-tumorous tissues. The expression of Jagged 2 mRNA and protein in colon carcinoma was significantly higher than that in matched adjacent non-tumorous tissues (P < 0.05). Immunohistochemical staining demonstrated that the percentage of Jagged 2 positive cells in colon carcinoma was significantly higher than that in matched adjacent non-tumorous tissues (85.7% vs 33.3%, χ² = 23.92, P < 0.01), and the expression of Jagged 2 had a significant correlation with histopathological grade, Duke's stage, depth of invasion, and lymph node metastasis (P < 0.05).

CONCLUSION

The expression of Jagged 2 is up-regulated in colon carcinoma, suggesting that Jagged 2 may be involved in the carcinogenesis, invasion, and metastasis of colon cancer.

Brucella induces unfolded protein response and inflammatory response via GntR in alveolar macrophages

Brucella is an intracellular bacterium that causes the zoonosis brucellosis worldwide. Alveolar macrophages (AM) constitute the main cell target of inhaled Brucella. Brucella thwarts immune surveillance and evokes endoplasmic reticulum (ER) stress to replicate in macrophages via virulence factors. The GntR regulators family was concentrated as an important virulence factor in controlling virulence and intracellular survival of Brucella. However, the detailed underlying mechanism for the host-pathogen interaction is poorly understood. In this study the BSS2_II0438 mutant (ΔGntR) was constructed. The type IV secretion system (T4SS) virulence factor genes (VirB2, VirB6, and VirB8) were down-expression in ΔGntR. ΔGntR could infect and proliferate to high titers in GAMs without a significant difference compared with the parental strain. ΔGntR infection increased the expression of ER stress marker genes GRP78, ATF6, and PERK in the early stages of its intracellular cycle but decreased the expression of these genes in the late stages. ΔGntR increased greatly the number of Brucella CFUs in the inactive ER stress state in GAMs. Meanwhile, ΔGntR infection increased the levels of IFN-γ, IL-1β, and TNF-α, indicating ΔGntR could induce the secretion of inflammatory but not anti-inflammatory cytokines IL-10. Taken together, our results clarified the role of the GntR in B. suis. S2 virulence expression and elucidated that GntR is potentially involved in the signaling pathway of the Brucella-induced UPR and inflammatory response in GAMs.

[Investigation of pregestational diabetes mellitus in 15 hospitals in Guangdong province]

Objective: To investigate the morbidity, diagnostic profile and perinatal outcome of pregestational diabetes mellitus (PGDM) in 15 hospitals in Guangdong province. Methods: A total of 41 338 women delivered in the 15 hospitals during the 6 months, 195 women with PGDM (PGDM group) and 195 women with normal glucose test result (control group) were recruited from these tertiary hospitals in Guangdong province from January 2016 to June 2016. The morbidity and diagnostic profile of PGDM were analyzed. The complications during pregnancy and perinatal outcomes were compared between the two groups. In the PGDM group, pregnancy outcomes were analyzed in women who used insulin treatment (n=91) and women who did not (n=104). Results: (1) The incidence of PGDM was 0.472%(195/41 338). Diabetes mellitus were diagnosed in 59 women (30.3%, 59/195) before pregnancy, and 136 women (69.7%,136/195) were diagnosed as PGDM after conceptions. Forty-six women (33.8%) were diagnosed by fasting glucose and glycohemoglobin (HbA1c) screening. (2) The maternal age, pre-pregnancy body mass index (BMI) , prenatal BMI, percentage of family history of diabetes, incidence of macrosomia, concentration of low density lipoprotein were significantly higher in PGDM group than those in control group (all P<0.05). Women in PGDM group had significantly higher HbA1c concentration ((6.3±1.3)% vs (5.2±0.4)%) , fasting glucose [(6.3±2.3) vs (4.8±1.1) mmol/L], oral glucose tolerance test (OGTT) -1 h glucose ((12.6±2.9) vs (7.1±1.3) mmol/L) and OGTT-2 h glucose [(12.0±3.0) vs (6.4±1.0) mmol/L] than those in control group (P<0.01). (3) The morbidity of preterm births was significantly higher (11.3% vs 1.0%, P<0.01), and the gestational age at delivery in PGDM group was significantly smaller [(37.6±2.3) vs (39.2±1.2) weeks, P<0.01]. Cesarean delivery rate in the PGDM group (70.8% vs 29.7%) was significantly higher than the control group (P<0.01). There was significantly difference between PGDM group and control in the neonatal male/female ratio (98/97 vs 111/84, P=0.033). The neonatal birth weight in PGDM group was significantly higher ((3 159±700) vs (3 451±423) g, P<0.01) . And the incidence of neonatal hypoglycemia in the PGDM group was higher than the control group (7.7% vs 2.6%, P=0.036). (4) In the PGDM group, women who were treated with insulin had a smaller gestational age at delivery [(36.9±2.9) vs (37.9±2.5) weeks, P<0.01], and the neonates had a higher neonatal ICU (NICU) admission rate (24.2% vs 9.6%, P<0.01). Conclusions: The morbidity of PGDM in the 15 hospitals in Guangdong province is 0.472%. The majority of PGDM was diagnosed during pregnancy; HbA1c and fasting glucose are reliable parameters for PGDM screening. Women with PGDM have obvious family history of diabetes and repeated pregnancy may accelerate the process of diabetes mellitus. Women with PGDM have higher risk for preterm delivery and neonatal hypoglycemia. Unsatisfied glucose control followed by insulin treatment may increase the need for NICU admission.

Influence of KLF17 overexpression on epithelial-mesenchymal transition and invasion of SW480 colorectal cancer cells

AIM

To assess the impact of KLF17 overexpression on the epithelial-mesenchymal transition (EMT) and invasive ability of SW480 colorectal cancer cells.

METHODS

The recombinant KLF17 expression plasmid with EGFP was transfected into SW480 cells, and non-transfected SW480 cells and SW480 cells transfected with the empty vector were used as controls. The changes in KLF17 mRNA and protein expression were detected by real-time PCR and Western blot at 48 h after transfection with the recombinant KLF17 expression plasmid. The changes in the expression of epithelial and mesenchymal makers in SW480 cells were detected by real-time PCR and Western blot. Transwell chamber invasion assay was used to investigate the effect of KLF17 gene transfection on the invasive potential of SW480 cells.

RESULTS

The expression levels of KLF17 mRNA and protein in SW480 cells transfected with the recombinant plasmid (2.5087 ± 0.0288; 0.6100 ± 0.0579) were significantly increased compared with those in non-transfected SW480 cells (1.0000 ± 0.0198; 0.3543 ± 0.0340) (P < 0.01 for both). The expression levels of E-cadherin mRNA and protein in SW480 cells transfected with the recombinant plasmid (2.0704 ± 0.0620; 0.5446 ± 0.0245) were significantly higher than those in non-transfected SW480 cells (1.0000 ± 0.0106; 0.3952 ± 0.0430) (P < 0.01 for both), while the expression levels of vimentin mRNA and protein in SW480 cells transfected with the recombinant plasmid (0.4622 ± 0.0279; 0.3290 ± 0.0367) were significantly lower than those in non-transfected SW480 cells (1.0000 ± 0.0780; 0.5229 ± 0.0496) (P < 0.01 for both). After transfection with the recombination KLF17 expression plasmid, the invasive ability of SW480 cells (86.67 ± 10.97) was significantly lower than that of non-transfected SW480 cells (145.30 ± 11.37) and SW480 cells transfected with the empty vector (135.33 ± 12.66) (P < 0.01 for both).

CONCLUSION

KLF17 may inhibit SW480 cancer cell invasion by inhibiting EMT.

Effect of siRNA-mediated inhibition of KLF17 expression on cell proliferation and migration in human colon cancer cell line SW480

AIM

To inhibit Krüppel like factor 17 (KLF17) gene expression in human colorectal carcinoma SW480 cells by small interfering RNA (siRNA) technique, and thereby observe the effect of KLF17 gene silencing on the proliferation and migration of SW480 cells, in order to provide the theoretical foundation for inhibiting the recurrence and metastasis of colorectal cancer.

METHODS

A KLF17 siRNA eukaryotic plasmid expression vector was constructed using genetic recombination, which was then transfected into SW480 cells by electroporation. Fluorescence quantitative PCR was used to detect the mRNA expression levels of KLF17, E-cadherin and Vimentin, while the protein expression of KLF17, E-cadherin and Vimentin was detected by Western blot. The proliferative activity of SW480 cells was assayed by MTT assay.

RESULTS

Compared with the control group, the proliferation ability of siRNA-transfected SW480 cells was significantly suppressed, and the cell morphology changed from round or polygonal to fusiform and cells developed many projections. After siRNA transfection, the mRNA and protein expression levels of KLF17 and E-cadherin were significantly decreased, and the levels of Vimentin mRNA and protein expression were significantly increased in the siRNA interference group.

CONCLUSION

Down-regulation of KLF17 expression in human colorectal carcinoma SW480 cells may promote cell proliferation and enhance cell migration by inducing epithelial-mesenchymal transition.

Clinical application of laparoscopic cylindrical abdominoperineal resection and extraperitoneal sigmoidostomy for low rectal cancer

AIM: To evaluate the clinical efficacy of laparoscopic cylindrical abdominoperineal resection and extraperitoneal sigmoidostomy for low rectal cancer.

METHODS: We retrospectively analyzed the clinicopathological data for 25 low rectal cancer patients who underwent laparoscopic cylindrical abdominoperineal resection and extraperitoneal sigmoidostomy at the First Hospital of Wuhan from January 2013 to February 2015.

RESULTS: Laparoscopic surgery was successful in all the 25 cases. Operative time was 162.5 min ± 35.6 min, and intraoperative blood loss was 55.5 mL ± 26.8 mL. Fat liquefaction and infection at the perineal incision occurred in two cases. After a median follow-up of 25 mo (range, 3-36 mo), no recurrence occurred.

CONCLUSION: Laparoscopic cylindrical abdominoperineal resection plus extraperitoneal sigmoidostomy is feasible for low rectal cancer and is associated with few complications, low recurrence rate, and satisfactory short-term curative effect.

InGaN light-emitting diode stripes with reduced luminous exitance

InGaN light-emitting diodes of stripe geometries have been demonstrated. The elongated geometry facilitates light spreading in the longitudinal direction. The chips are further shaped by laser-micromachining to have partially-inclined sidewalls. The light extraction efficiencies of such 3D chip geometries are enhanced by ~12% (~8% according to ray-trace simulations), leading to a reduction of junction temperatures. The effective emission area is also increased four times compared to a cubic chip. The stripe LEDs are thus more efficient emitters with reduced luminous exitance, making them more suitable for a wide range of lighting applications.

[Clinical analysis for systemic complications of patients in the dental emergency room]

OBJECTIVE

To analyze the clinical features of oral emergency patients in general health, and to guide the oral emergency patients in the treatment, and prevention of accidents.

METHODS

The retrospective study was performed on the day visits to the emergency department in Peking University School and Hospital of Stomatology from February to November 2013.The basic information of the newly diagnosed adult, their overall health status, American society of anesthesiologists(ASA) classification and oral diagnosis information were analyzed and summarized.

RESULTS

The cardiovascular and cerebrovascular diseases(6.4%), hypertension(13.4%), endocrine system diseases(4.2%)were most common in the patients. With the increase of age, the associated systemic diseases had increased in number and in ASA classification. Periapical disease(24.6%), dental pulp disease(24.4%), and periodontal disease(18.0%) accounted for about 2/3.

CONCLUSION

The general health status of patients with oral emergency worsened with the increase of age. Oral surgeons should make risk assessment before treatment. ASA classification system can help doctors predict the patient risk, take corresponding measures in advance, and help to reduce the occurrence of accidents.

High sensitivity 10Gb/s Si photonic receiver based on a low-voltage waveguide-coupled Ge avalanche photodetector

We demonstrate low-voltage germanium waveguide avalanche photodetectors (APDs) with a gain × bandwidth product above 100GHz. A photonic receiver based on such a Ge APD, including a 0.13μm SiGe BiCMOS low-noise trans-impedance amplifier and a limiting amplifier, is realized. A 5.8dB sensitivity improvement is demonstrated at -5.9V bias at an avalanche gain of 6 through bit error ratio measurements. The absolute sensitivity in avalanche mode is -23.4dBm and -24.4dBm at a bit error ratio of 1 × 10(-12) and 1 × 10(-9) respectively.

Simultaneous rupture of bilateral quadriceps tendon and rotator cuff tear: a case report

This is a case report of a patient who sustained both a bilateral quadriceps tendon rupture and a complete rotator cuff tear. Overuse is a known risk factor for rotator cuff tears, but this case suggests that it can also be a risk factor for quadriceps tendon rupture.

Oxygen vacancy density-dependent transformation from infrared to Raman active vibration mode in SnO2 nanostructures

Raman spectra acquired from spherical, cubic, and cuboid SnO2 nanocrystals (NCs) reveal a morphologically independent Raman mode at ∼302 cm(-1). The frequency of this mode is slightly affected by the NC size, but the intensity increases obviously with decreasing NC size. By considering the dipole changes induced by oxygen vacancies and derivation based on the density functional theory and phonon confinement model, an oxygen vacancy density larger than 6% is shown to be responsible for the transformation of the IR to Raman active vibration mode, and the intensity enhancement is due to strong phonon confinement.

Characterization of yeasts colonizing in healthy individuals

Opportunistic yeast pathogens may switch from harmless commensal to pathogenic relationships with the host under different conditions. They usually cause superficial infections, but may be the agents of more significant infections in immunocompromised patients. To investigate yeast colonization in the oral cavities of clinically healthy individuals, we collected oral swabs from 323 students and staff at the National Health Research Institutes, Taiwan. A total of 49 (15.2%) volunteers were colonized by low levels of yeasts and of these, only 3 (6.1%) were co-colonized by more than one species. Among the 52 isolates, comprising seven fungal genera and 13 species, Candida albicans (57.7%) was the dominant species, followed by Candida parapsilosis (15.4%). There was only one isolate of C. parapsilosis that showed, in vitro, a high (2 μg/ml) minimum inhibitory concentration (MIC) to amphotericin B. There were six (11.5%) isolates with fluconazole MICs ≥ 64 μg/ml and all of them were non-Candida species. With the exception of Cryptococcus albidus, the remaining five isolates had voriconazole MICs ≥ 4 μg/ml. In addition, there was one C. albicans isolate with relatively high fluconazole (32 μg/ml) and voriconazole (4 μg/ml) MICs.

Syntheses and growth mechanisms of 3C-SiC nanostructures from carbon and silicon powders

Cubic silicon carbide (3C-SiC) nanostructures such as needle- and Y-shaped nanowhiskers, smooth and pagoda-shaped nanorods are synthesized on a large scale from activated carbon and silicon powders at 1250 degrees C under atmospheric pressure. The use of ball-milled silicon powders results in the formation of nanowires and nanowhiskers, whereas non-milled silicon powders lead to nanorods together with unreacted silicon powders. Residual oxygen in the growth chamber initiates the carburization reactions which can proceed without further oxygen consumption. The size and morphology of the as-synthesized 3C-SiC nanostructures are observed to be related to the size and morphology of the starting silicon particles. An oxygen-assisted gas-solid model is proposed to explain the observed nanostructures.

Synthesis and characteristics of cubic silicon carbide nanospheres with smooth surfaces

Large quantities of cubic silicon carbide (3C-SiC) nanospheres are synthesized on silicon wafer using zinc sulphide (ZnS) and activated carbon powder. The synthesized nanospheres have smooth surfaces and their diameters range from 20 to 430 nm. The growth of these nanospheres can be explained by a gas-solid model. ZnS powder plays a key role in the formation of activated Si and SiOx. Carburization of the activated Si and SiOx by CO gas leads to the formation of the 3C-SiC nanospheres. Special three-dimensional structure of the product is related to high concentrations of the reactants.

Piezoresistive characteristics of MWNT nanocomposites and fabrication as a polymer pressure sensor

Polyimide (PI)-carbon nanotube composites were fabricated by in situ polymerization using multi-wall carbon nanotubes (MWNT) as fillers. The composite film was characterized by some analytical instruments to ensure its structure and good dispersion of the MWNTs in the composites. The electrical resistivity of this composite was found to vary significantly with both the temperature and the stress in the material. The PI-MWNT composites possess a very linear piezoresistive nature which can be used as a good pressure sensor material, provided with proper temperature compensation. Fabrication of a micropolymer pressure sensor using this nanocomposite sensing material is demonstrated and sensor performance is evaluated. The sensor has a higher sensitivity than a polysilicon sensor, rapid response, and is thermally stable. The sensor is suitable for mass production, and can be widely applied or integrated in a microfluidic system or biochip where pressure information is required.

Tin oxide nanoribbons with vacancy structures in luminescence-sensitive oxygen sensing

Vacancy structures in tin oxide nanoribbons fabricated via thermal evaporation and post-processing are probed by luminescence spectroscopy, and interesting properties that bode well for oxygen sensing are observed. Besides a broad 620-nm band, the fabricated tin oxide nanoribbons show a photoluminescence band at 480 nm when the measurement temperature is <100 K. The blue band appears from nanoribbons synthesized under high oxygen pressure or annealed under oxygen. The dependence suggests that the oxygen interstitial and vacancy densities determine the electronic states that produce the blue band. Calculation of the electron structures based on the density functional theory shows that decreased oxygen vacancies or increased oxygen interstitials enhance the 480-nm band but suppress the 620-nm band. The results reported here indicate that the tin oxide nanoribbons with vacancy structures have potential applications in luminescence-sensitive oxygen sensing.

A process evaluation of the implementation of a computer-based, health provider-delivered HIV-prevention intervention for HIV-positive men who have sex with men in the primary care setting

There is increasing interest in using healthcare providers to deliver HIV-prevention services to their patients. Unfortunately, lack of counselling skills and time constraints within busy clinics serve as barriers to such efforts. The Providers Advocating for Sexual Health Initiative (PASHIN) study used state-of-the-art computer technology to assess each participant's risk behaviours and to determine the patient's readiness for changing each behaviour. The computer synthesized the participant-entered data, determined the targeted risk behaviour and printed a behavioural theory-based provider advice sheet and a 3-point patient prescription for the targeted risk behaviour. Since the intervention does not require providers to spend time performing a detailed sexual-risk assessment and it does not require providers to have received extensive counselling training, it has the potential to minimize some of the barriers associated with provider-delivered interventions. Thus, the purpose of this process evaluation was to assess how the PASHIN intervention was implemented in the field, including issues such as the fidelity of implementation and health providers' views on and experience with implementing the intervention. Overall, the results demonstrated that the computer-based, provider-delivered intervention was successfully delivered by providers within the context of regularly scheduled treatment sessions with HIV-positive men who have sex with men (MSM) patients. The majority of providers (79.4%) and patients (83.5%) reported that the quality of HIV-prevention services delivered during these sessions was 'good'. The majority of the providers also reported that they had received adequate training, felt more confident in communicating HIV-prevention issues with their patients and provided more HIV-prevention counselling to their patients, due to the project. However, the experience of delivering HIV-prevention counselling during an 18-month period did not appear to change providers' attitudes toward a provider-delivered HIV-prevention intervention nor their belief in the effectiveness of HIV prevention in general. Future studies should focus on how to enhance providers' acceptance and commitment to delivering HIV-prevention counselling to their patients during the clinic visit.

Identification of a novel insulin-like growth factor binding protein gene homologue with tumor suppressor like properties

Here we report the identification of a new insulin-like growth factor binding protein homologue, provisionally designated insulin-like growth factor binding related protein-4 (IGFBP-rP4). IGFBP-rP4 was found to be most closely related to IGFBP-7 with 52% amino acid homology and 43% amino acid identity, and shares a similar domain structure. Semi-quantitative RT-PCR expression analysis demonstrated a pattern of downregulation of this gene in multiple tumor samples including lung and colon cancer, compared to matched adjacent normal tissue. Western blotting revealed a protein of approximately 38kDa expressed in both the cell pellet and secreted into the supernatant of transiently transfected Cos-7 cells. Cos-7 supernatants containing IGFBP-RP4 protein were observed to suppress the growth of HeLa cells in culture compared to vector controls. IGFBP-RP4 directly transiently transfected into HeLa cells also further confirmed the growth suppressive properties of this protein. Together these data suggest that IGFBP-RP4 may be a novel putative tumor suppressor protein.

Farnesol for aerosol inhalation: nebulization and activity against human lung cancer cells

PURPOSE

A nebulized aerosol formulation of the anti-cancer agent farnesol is developed and shown to induce cell death of human lung cancer cells in vitro.

METHODS

A nebulized farnesol formulation containing polysorbate 80 (Tween 80) is developed. The measurements of the aerosol properties during nebulization were used as input for a mathematical model of airway surface liquid in the lung of an average adult, to estimate the airway surface liquid drug concentration of the deposited farnesol. Cytotoxicity of the formulations was measured in vitro on non-small cell lung cancer cells (H460 and A549).

RESULTS

As much as 100% of lung cancer cytotoxicity can be achieved by using Pari LC Star and LC Plus nebulizers. The estimated airway surface liquid concentrations of the deposited farnesol reveal that the IC50 of the nebulized farnesol can be achieved over the entire tracheobronchial region, using the above Pari nebulizers with a volume fill of 5 ml.

CONCLUSIONS

Drug concentrations higher than IC50 in the airway surface liquid are predicted with our methods, suggesting in vivo trials of a formulation may be warranted with these particular nebulizers.

The role of recombination activating gene (RAG) reinduction in thymocyte development in vivo

Assembly of T cell receptor (TCR)alpha/beta genes by variable/diversity/joining (V[D]J) rearrangement is an ordered process beginning with recombination activating gene (RAG) expression and TCRbeta recombination in CD4(-)CD8(-)CD25(+) thymocytes. In these cells, TCRbeta expression leads to clonal expansion, RAG downregulation, and TCRbeta allelic exclusion. At the subsequent CD4(+)CD8(+) stage, RAG expression is reinduced and V(D)J recombination is initiated at the TCRalpha locus. This second wave of RAG expression is terminated upon expression of a positively selected alpha/beta TCR. To examine the physiologic role of the second wave of RAG expression, we analyzed mice that cannot reinduce RAG expression in CD4(+)CD8(+) T cells because the transgenic locus that directs RAG1 and RAG2 expression in these mice is missing a distal regulatory element essential for reinduction. In the absence of RAG reinduction we find normal numbers of CD4(+)CD8(+) cells but a 50-70% reduction in the number of mature CD4(+)CD8(-) and CD4(-)CD8(+) thymocytes. TCRalpha rearrangement is restricted to the 5' end of the Jalpha cluster and there is little apparent secondary TCRalpha recombination. Comparison of the TCRalpha genes expressed in wild-type or mutant mice shows that 65% of all alpha/beta T cells carry receptors that are normally assembled by secondary TCRalpha rearrangement. We conclude that RAG reinduction in CD4(+)CD8(+) thymocytes is not required for initial TCRalpha recombination but is essential for secondary TCRalpha recombination and that the majority of TCRalpha chains expressed in mature T cells are products of secondary recombination.

Clinical analysis and literature review of massive duodenal diverticular bleeding

A duodenal diverticulum (DD) appears in 2.5% of upper gastrointestinal (UGI) examinations and up to 22% of endoscopic retrograde cholangiopancreaticographies (ERCP) and autopsies. Most of these patients are asymptomatic, but the lesion is occasionally associated with bleeding, inflammation, perforation, obstruction of the duodenum or biliary-pancreatic duct (or both), fistula formation in the bile duct, and bezoar formation inside the diverticulum. A total of 816 patients have undergone ERCP examination at our institution since January 1987, and 100 (12.25%) of them have DD. Seven (7%) patients presented with bloody or tarry stools from massive UGI bleeding followed by shock. Only two could be diagnosed by UGI endoscopy preoperatively. The lesions were demonstrated in angiographic studies in another four cases. However, only one was correctly interpreted and one required reoperation after a correct repeat endoscopic finding. The lesions in the other two patients were identified by thorough exploration during laparotomy. The remaining case was diagnosed by intraoperative endoscopy via pyloroduodenotomy. Six underwent surgical intervention, and one was successfully treated by expectant treatment. Three (50%) had leakage from the duodenotomy but recovered uneventfully with conservative treatment. In conclusion, we believe that DD bleeding is more frequent than usually thought. A high index of suspicion should be raised in cases of UGI bleeding when more obvious and common causes have been excluded by routine endoscopy. Aggressive but careful endoscopic examination combined with accurate angiography can help us diagnose most of the cases preoperatively. Diverticulectomy is an effective surgical procedure, though it is associated with a considerable leakage rate. The morbidity is minimal if we can identify the lesion earlier and evacuate the lesion without delay.

Proton-lithium binding behavior of tris(2-((pyrid-2-ylmethyl)uredio)ethyl)amine

Tris(2-((pyrid-2-ylmethyl)uredio)ethyl)amine (2) and its perchlorate salt, 2.HClO(4), bind with Li+ in nitromethane in a 1:1 fashion. The stability constants of K(Li+) and K(H)(Li+) were found to be 112 +/- 25 and 130 +/- 30 M(-)(1) in CD(3)NO(2), respectively. Formation of the 1:1 complexes were further evidenced by electrospray ionization mass spectrometry (ESI-MS). The slight increase, or at least the same order of magnitude, of K(H)(Li+) compared to K(Li+) points to a remarkable preorganization of the protonated podand in 2.HClO(4), that essentially overcomes the increased Columbic repulsion occurring on complexation to Li+.

Effect of radiation on cytokine and cytokine receptor messenger-RNA profiles in p53 wild and mutated human glioblastoma cell lines

OBJECTIVE

Glioblastoma cells produce cytokines with proinflammatory or immunosuppressive properties, or both, which, in addition to altered p53 gene expression, have been shown to be associated with glioblastoma resistance to radiotherapy. The reported data concerning cytokines have been isolated and sometimes discordant, and a comprehensive profile analysis of cytokines and their corresponding receptors in irradiated glioblastomas has received limited attention. The object of this study was to test the hypothesis that radiation alone in clinically relevant doses would not significantly alter expression of endogenous cytokines and their receptors in human glioblastoma celll ines with wild-type and mutant p53.

DESIGN AND METHOD

Culture specimens of 4 glioblastoma cell lines of different p53 gene expression (U87, U118, U251, U373) were irradiated with cobalt 60 at a dose of 10 Gy. After 48 hours, radiosensitivity was defined through a colony formation assay, cell cycle distribution was analyzed by flow cytometry, and cytokine and cytokine receptor messenger-RNA (mRNA) profiles were defined with an RNase protection assay. Different single doses of radiation at varying time intervals after culture were applied also to wild-type p53 cell lines.

RESULTS

All cell lines were relatively radioresistant at lower doses of 1 and 2 Gy. Immunosuppressive cytokine and cytokine receptor mRNA of the Th2 (IL-13Ralpha, IL-4) and Th3 family (TGF-beta1, 2 and 3, TGF-betaRI and RII) were expressed. In contrast, only 2 proinflammatory Th1 cytokine receptor genes (IFN-gammaRa and IFN-gammaRbeta), but no significant Th1 cytokine gene expression, were detected. Even though the population examined included a large fraction of reproductively dead cells, cytokine and cytokine receptor mRNA profiles were not altered significantly by irradiation in all cell lines, regardless of the p53 status.

CONCLUSION

These results suggest that cobalt irradiation alone at clinically relevant doses does not significantly alter the cytokine and cytokine receptor profiles in human glioblastoma cell lines.

Genetic interactions between ATM and the nonhomologous end-joining factors in genomic stability and development

DNA ligase IV (Lig4) and the DNA-dependent protein kinase (DNA-PK) function in nonhomologous end joining (NHEJ). However, although Lig4 deficiency causes late embryonic lethality, deficiency in DNA-PK subunits (Ku70, Ku80, and DNA-PKcs) does not. Here we demonstrate that, similar to p53 deficiency, ataxia-telangiectasia-mutated (ATM) gene deficiency rescues the embryonic lethality and neuronal apoptosis, but not impaired lymphocyte development, associated with Lig4 deficiency. However, in contrast to p53 deficiency, ATM deficiency enhances deleterious effects of Lig4 deficiency on growth potential of embryonic fibroblasts (MEFs) and genomic instability in both MEFs and cultured progenitor lymphocytes, demonstrating significant differences in the interplay of p53 vs. ATM with respect to NHEJ. Finally, in dramatic contrast to effects on Lig4 deficiency, ATM deficiency causes early embryonic lethality in Ku- or DNA-PKcs-deficient mice, providing evidence for an NHEJ-independent role for the DNA-PK holoenzyme.

Giant ethmoid osteoma with orbital extension, a nasoendoscopic approach using an intranasal drill

OBJECTIVE

Ethmoid osteoma is a slow-growing, benign, and encapsulated bony tumor. Symptoms occur earlier than with osteomas of the frontal sinus because of the small volume of the ethmoid sinus. Interestingly, orbital extension is uncommon. Treatment remains controversial, with open procedures typically being used. In this article, we present a less invasive yet safe and effective approach to treatment.

STUDY DESIGN

A nasoendoscopic approach using a Stammberger-Saches intranasal drill was developed for treatment of patients with ethmoid osteoma, with or without orbital extension. Between 1995 to 1999, seven patients underwent the new surgical procedure.

METHODS

All procedures were performed under general anesthesia. Using 0 degrees and 30 degrees endoscopes, surface anesthesia of the nasal mucosa was performed, the anterior ethmoid cell was resected, and the whitish osteoma found. The osteoma was drilled out inferolaterally to superomedially. In the patient with orbital extension, a double-ended blunt elevator was used to separate the remaining osteoma from the lamina papyracea and to push the residual osteoma medially toward the nasal septum. With alternate drilling and elevation, the osteoma was gently removed. The surgical site was then packed.

RESULTS

The method successfully treated all patients. There were no major complications. The single patient with orbital extension had mild postoperative periorbital ecchymoses. Nasoendoscopy showed normal epithelialization 4 to 6 weeks after surgery. Computed tomography showed no residual tumors 6 months after surgery.

CONCLUSION

The 30 degrees nasoendoscopic approach using an intranasal drill provides a good operative field and is a safe and effective technique, with the potential to become the treatment of choice in selected cases.

Primary renal sarcoma with inferior vena cava thrombus presenting with tumor rupture

Primary renal sarcoma represents approximately one per cent of all primary tumors of the kidney in adults. We report an unusual case of primary renal sarcoma with inferior vena cava (IVC) thrombus. This patient presented with hemorrhagic shock due to tumor rupture. Emergent radical nephrectomy and vena caval thrombectomy were performed. Histological examination proved a clear cell sarcoma.

Enhanced sensitivity and long-term G2 arrest in hydrogen peroxide-treated Ku80-null cells are unrelated to DNA repair defects

While the Ku complex, comprised of Ku70 and Ku80, is primarily involved in the repair of DNA double-strand breaks, it is also believed to participate in additional cellular processes. Here, treatment of embryo fibroblasts (MEFs) derived from either wild-type or Ku80-null (Ku80(-/-)) mice with various stress agents revealed that hydrogen peroxide (H(2)O(2)) was markedly more cytotoxic for Ku80(-/-) MEFs and led to their long-term accumulation in the G2 phase. This differential response was not due to differences in DNA repair, since H(2)O(2)-triggered DNA damage was repaired with comparable efficiency in both Wt and Ku80(-/-) MEFs, but was associated with differences in the expression of important cell cycle regulatory genes. Our results support the notion that Ku80-mediated cytoprotection and G2-progression are not only dependent on the cell's DNA repair but also may reflect Ku80's influence on additional cellular processes such as gene expression.

Structure of a (Cys3His) zinc ribbon, a ubiquitous motif in archaeal and eucaryal transcription

Transcription factor IIB (TFIIB) is an essential component in the formation of the transcription initiation complex in eucaryal and archaeal transcription. TFIIB interacts with a promoter complex containing the TATA-binding protein (TBP) to facilitate interaction with RNA polymerase II (RNA pol II) and the associated transcription factor IIF (TFIIF). TFIIB contains a zinc-binding motif near the N-terminus that is directly involved in the interaction with RNA pol II/TFIIF and plays a crucial role in selecting the transcription initiation site. The solution structure of the N-terminal residues 2-59 of human TFIIB was determined by multidimensional NMR spectroscopy. The structure consists of a nearly tetrahedral Zn(Cys)3(His)1 site confined by type I and "rubredoxin" turns, three antiparallel beta-strands, and disordered loops. The structure is similar to the reported zinc-ribbon motifs in several transcription-related proteins from archaea and eucarya, including Pyrococcus furiosus transcription factor B (PfTFB), human and yeast transcription factor IIS (TFIIS), and Thermococcus celer RNA polymerase II subunit M (TcRPOM). The zinc-ribbon structure of TFIIB, in conjunction with the biochemical analyses, suggests that residues on the beta-sheet are involved in the interaction with RNA pol II/TFIIF, while the zinc-binding site may increase the stability of the beta-sheet.

Experimental examination of the effects of atmospheric wet deposition on primary production in the Yellow Sea

The effects of atmospheric wet deposition on primary production in the coastal Yellow Sea were examined by in situ incubation experiments in August, 1997. Phytoplankton species flourished in response to nutrient additions and chlorophyll-a (Chl-a) increased significantly when rainwater was added. Concentration of Chl-a increased 2.6 times with the addition of 10% (v/v) rainwater. In a coastal eutrophic region like Jiaozhou Bay, the impact of atmospheric wet deposition is negligible. However, the N/P ratio ranged from 22:1 to 80:1, indicating P limitation of photosynthesis in the Yellow Sea. During field observations, high N and low P rainwater was observed to be transported into the oligotrophic central Yellow Sea. Ammonium was used by phytoplankton in preference to nitrate, and Fe stimulated nutrient uptake by phytoplankton. Rainwater increased the Chl-a growth more than a single nutrient owing to the abundance of both plant and trace nutrients in the rainwater. A negative exponent relationship may exist between the impact of rainwater and total nutrient quality of the water in influencing phytoplankton growth.

DNA repair protein Ku80 suppresses chromosomal aberrations and malignant transformation

Cancer susceptibility genes have been classified into two groups: gatekeepers and caretakers. Gatekeepers are genes that control cell proliferation and death, whereas caretakers are DNA repair genes whose inactivation leads to genetic instability. Abrogation of both caretaker and gatekeeper function markedly increases cancer susceptibility. Although the importance of Ku80 in DNA double-strand break repair is well established, neither Ku80 nor other components of the non-homologous end-joining pathway are known to have a caretaker role in maintaining genomic stability. Here we show that mouse cells deficient for Ku80 display a marked increase in chromosomal aberrations, including breakage, translocations and aneuploidy. Despite the observed chromosome instabilities, Ku80-/- mice have only a slightly earlier onset of cancer. Loss of p53 synergizes with Ku80 to promote tumorigenesis such that all Ku80-/- p53-/- mice succumb to disseminated pro-B-cell lymphoma before three months of age. Tumours result from a specific set of chromosomal translocations and gene amplifications involving IgH and c-Myc, reminiscent of Burkitt's lymphoma. We conclude that Ku80 is a caretaker gene that maintains the integrity of the genome by a mechanism involving the suppression of chromosomal rearrangements.

Acute colonic intramural hematoma due to blunt abdominal trauma

Trauma to the colon is uncommon and accounts for only 3-5% of all blunt abdominal injuries. Among them, intramural hematoma of the colon is a rare complication and the acute form is rarer than the chronic form. We report a 37-year-old man who presented with abdominal pain followed by intestinal obstruction due to a blunt trauma. The initial diagnosis was done by sonography and proved by computed tomography (CT). Abdominal sonography also detected an increment in the size of the hematoma with progressive abdominal cramping pain that prompted urgent laparotomy. Ileocolic segmental resection with end-to-end ileocolostomy was performed and the patient recovered uneventfully. Based on our experience with a patient suffering from an intramural colonic hematoma following blunt abdominal trauma (BAT) and based on a review of the literature, we discuss the different clinical manifestations, difficulties of diagnosis, and different treatment modalities of this disease entity. We conclude that acute colonic hematoma can be diagnosed by sonography and/or CT in contrast to the early reported cases, in the pre-CT era, when they could only be diagnosed at laparotomy. Endoscopy may also be helpful for diagnosis in some cases. Although expectant therapy may be successful in some cases, the majority of the cases may need operation.

Endoscopic carpal tunnel release

BACKGROUND

Endoscopic carpal tunnel release was developed by Okutsu and Chow in 1989. Many reports have indicated that endoscopic carpal tunnel release diminishes postoperative pain and accelerates the recovery time.

METHODS

In a series of 1278 carpal tunnel release procedures (in 948 patients), 1214 were performed with a modified Menon endoscopic method and the remaining 64 with an open procedure. The patients with idiopathic carpal tunnel syndrome were followed for at least 3 months.

RESULTS

Of the endoscopic release patients, 80.9% recovered grip strength equal to or greater than preoperative levels within 4 weeks, whereas in the open procedure group, the rate was only 59.3%. The difference was statistically significant (p = 0.00011). An immediate complication was one median motor nerve severance. There were 24 conversions to a conventional open procedure during endoscopic release. In the endoscopic group, 81% developed scar tenderness over the thenar crease, 31% developed new sensory disturbance, and 4% developed pillar pain.

CONCLUSION

Endoscopic release facilitated the recovery of grip strength and diminished the frequency of scar tenderness. However, neurovascular injury should be carefully prevented.

Differential binding of proteins to peroxisomes in rat hepatoma cells: unique association of enzymes involved in isoprenoid metabolism

Farnesyl diphosphate synthase (FPPS: EC2.5.1.10), a key enzyme in isoprenoid metabolic pathways, catalyzes the synthesis of farnesyl diphosphate (FPP) an intermediate in the biosynthesis of both sterol and non-sterol isoprenoid end products. The localization of FPPS to peroxisomes has been reported (Krisans, S. K., J. Ericsson, P. A. Edwards, and G. A. Keller. 1994. J. Biol. Chem. 269: 14165;-14169). Using indirect immunofluorescence and immunoelectron microscopic techniques we show here that FPPS is localized predominantly in the peroxisomes of rat hepatoma H35 cells. However, the partial release of 60;-70% of cellular FPPS activity is observed by selective permeabilization of these cells with digitonin. Under these conditions, lactate dehydrogenase, a cytosolic enzyme, is completely released whereas catalase, a known peroxisomal enzyme, is fully retained. Digitonin treatment of H35 cells differentially affects the release of other peroxisomal enzymes involved in isoprenoid metabolism. For instance, mevalonate kinase and phosphomevalonate kinase are almost totally released (95% and 91%, respectively), whereas 3-hydroxy-3-methylglutaryl-CoA reductase is fully retained. Indirect immunoflourescence studies indicate that FPPS is localized in peroxisomes of Chinese hamster ovary (CHO)-K1 cells but is dispersed in the cytosol of ZR-82 cells, a mutant that lacks peroxisomes. Unlike in H35 cells, FPPS is completely released upon digitonin permeabilization of CHO-K1 and ZR-82 cells. In contrast, under the same permeabilization conditions, catalase is fully retained in CHO-K1 cells but completely released from ZR-82 cells. These studies indicate that FPPS and other enzymes in the isoprenoid biosynthetic pathways, involved in the formation of FPP, are differentially associated with peroxisomes and may easily diffuse to the cytosol. Based on these observations, the significance and a possible regulatory model in the formation of isoprenoid end-products are discussed.

Correlation of clinical and ultrasonographic features in congenital muscular torticollis

OBJECTIVE

To find the relationship between the ultrasonographic pictures and the clinical features of patients with congenital muscular torticollis (CMT).

DESIGN

Prospective survey of patients with clinically suspected CMT by high-resolution ultrasonography.

SETTING

Rehabilitation department of a tertiary care center.

PARTICIPANTS

Two hundred fifty-six CMT patients, from the ages of 9 days to 16yrs, with a mean follow-up period of 6.7 months.

MAIN OUTCOME MEASURES

Correlation of the ultrasound appearance of the involved sternocleidomastoid (SCM) muscles with clinical features. The pathologic findings in diseased muscles from patients who underwent surgical intervention were also evaluated.

RESULTS

Muscle abnormalities were identified ultrasonographically in 218 CMT patients (85%) and were classified into four types: a fibrotic mass in the involved muscle (type I, 15%); diffuse fibrosis mixing with normal muscle (type II, 77%) and without normal muscle in the involved muscle (type III, 5%); and a fibrotic cord in the involved muscle (type IV, 3%). Compared with type I patients, type IV patients were more likely to undergo surgical treatment (odds ratio = 31.54, p = .0196). Type III patients were more likely to undergo surgical treatment, although this tendency was not statistically significant.

CONCLUSION

Ultrasonography can precisely identify pathologic changes in the involved SCM muscle of CMT patients. Type III and IV patients are more likely to require surgical intervention.

Involvement of farnesyl protein transferase (FPTase) in FcarepsilonRI-induced activation of RBL-2H3 mast cells

Changes in farnesyl protein transferase (FPTase) activity and FPTase beta-subunit protein levels were determined in IgE-sensitized RBL-2H3 mast cells in response to polyvalent antigen administration. Ten minutes after the addition of DNP modified BSA to mast cells, whose high affinity receptor for IgE (FcvarepsilonRI) contained bound anti-DNP IgE, FPTase specific activity increased by 54 +/- 28%. Time course studies showed FPTase specific activity doubled during a 20- to 30-min period after antigen-induced cell aggregation. Also, an increase in FPTase beta-subunit protein during this time ( approximately 30%) was observed; this protein increase was not accompanied by a similar increase in FPTase beta-subunit m-RNA levels. The FcvarepsilonRI aggregation had no significant effect on the activities of other enzymes involved with farnesyl diphosphate (FPP) metabolism: FPP synthase, isopentenyl diphosphate isomerase, geranylgeranyl protein transferase, and squalene synthase. Specific inhibition of FPTase activity by manumycin was studied to determine what role FPTase plays in mast cell activation. Manumycin profoundly inhibited hexosaminidase release in activated cells, indicating FPTase is required for signal transduction involved with protein exocytosis from RBL-2H3 mast cells.

Regulation of bovine interleukin-1 receptors

Interleukin-1 is a key player in inflammation and the immune response. The interleukin-1 family consists of three ligands (IL-1 alpha, IL-1 beta, and the IL-1 receptor antagonist) and two receptors (IL-1RI and IL-1RII). Previous studies suggest a dynamic relationship among these receptors and ligands that regulates the magnitude and extent of IL-1 mediated activities. Our laboratory has cloned and sequenced the bovine type I and II interleukin-1 receptors, and has begun to investigate their regulation in bovine leukocytes in vitro and in vivo. IL-1RI and IL-1RII mRNA levels were upregulated in vitro by various mediators, including dexamethasone, rBoIL-4, rBoGM-CSF, and rHuTNF alpha. Conversely, IL-1RI mRNA levels were down-regulated by IFN-gamma. An in vivo study indicated that IL-1RII mRNA levels increased earlier than IL-1RI mRNA levels in dexamethasone-treated cattle. These findings suggest that early upregulation of IL-1RII, which is a decoy receptor, may be part of the anti-inflammatory action of glucocorticoids. Our investigations suggest that anti-inflammatory agents increase expression of the biologically inactive IL-1RII, as compared with the biologically active IL-1RI, in bovine leukocytes.

Growth hormone receptor and regulation of gene expression in fetal lymphoid cells

The role of growth hormone (GH) in modulating the adult immune response is receiving increased attention; however, its role in the development of immune competence in the fetus has not been defined. In order to begin to address the role of GH in the ontogeny of the immune response. cells from bovine fetal spleen and thymus were examined for GH receptor and responsiveness to GH. Northern analysis and ligand binding studies showed that growth hormone receptor (GHR) was readily detected in early- and mid-gestational fetal thymocytes, but it was less readily detected in thymocytes from older fetuses. In contrast, GHR was easily detected in splenocytes at all fetal ages. Thymocytes and splenocytes from mid-gestational fetuses expressed low levels of cell surface GHR by flow cytofluorometric analysis, and CD4+ and CD8 (single positive) thymocyte subsets were positive. Northern analyses were employed to determine the effects of in vitro GH treatment on expression of several proto-oncogenes, cytokines, and GHR in thymocytes from fetuses at approximately mid-gestation. GH treatment for 30 min down-regulated c-jun and c-fos mRNA approximately 2- and 2.8-fold, respectively. After 6 h treatment, GH increased transcript levels for interleukin (IL)-1alpha, IL-1beta, IL-6, and GM-CSF about 2.5-, 2.2-, 3-, and 2-fold, respectively. GH also down-regulated the expression of its own receptor about 3.2-fold after 8 h of incubation. The presence of GHR in fetal lymphoid cells and its temporal and spatial regulation suggest a potential role for GH in the development and or function of the fetal bovine immune system. Although the mechanism(s) is unclear, our results suggest that GH is intimately involved in lymphocyte function and expression of certain cytokines during a critical period of fetal immune development.

Growth hormone and Pit-1 expression in bovine fetal lymphoid cells

Bovine fetal lymphoid cells were examined for growth hormone (GH) and the transcription factor Pit-1/GHF-1 mRNA. GH and Pit-1/GHF-1 transcripts were detected in thymocytes and splenocytes from fetuses at 60, 90, 120, and 270 d of gestation using reverse transcription-polymerase chain reaction (RT-PCR). Northern analysis indicated that the lymphoid GH mRNA was approximately 350 nucleotides larger than in the pituitary. RT-PCR analysis demonstrated that the coding regions as well as 3' untranslated region of the lymphocyte GH and pituitary transcripts were the same. Analysis of the 5'-untranslated region of the lymphocyte GH mRNA showed that transcription began upstream from the start site in the pituitary gland, suggesting differences in regulation in these tissues. Fetal thymocytes and splenocytes expressed Pit-1/GHF-1 mRNA; however, they contained only the 2.5-kb transcript. The GH and Pit-1/GHF-1 mRNA in fetal lymphoid cells supports the hypothesis that lymphocyte-derived GH may function as an autocrine and/or paracrine factor during the development and maturation of the bovine fetal immune system.

Free tissue transfer for leg reconstruction in children

Twenty-five free tissue transfers for reconstruction after lower limb trauma or release of scar contractures were performed in 23 children over an 8-year period. The ages ranged from 2 to 14 years (mean 7.1 years). Fourteen (61%) patients had major associated injuries. The reconstruction sites were all in the distal leg. The overall vascular success rate was 96%. Three patients underwent re-explorations because of vascular insufficiency. One flap failed and two were salvaged. The causes of vascular complications were considered to be inadequate debridement of an avulsed vessel, venous kinking and inadequate protection of the vascular pedicle. The three cases with vascular insufficiency were children with associated injuries on the ipsilateral leg proximally. Postoperative complications were not uncommon (28%). Six of the seven complications occurred in patients with major associated injuries. The mean follow-up was 57 months. Long-term problems such as a limping gait, frequent flap ulcers, toe contracture or a bulky flap were common. Our results suggest that free tissue transfer is reliable and safe for the reconstruction of major leg injuries in children. Associated injuries proximal to the reconstructed defects on the ipsilateral leg predispose to more vascular complications. Since postoperative complications and long-term morbidity are common in children, special precautions should be taken with the preoperative assessment, planning, execution of surgery and postoperative care to achieve better results.

Molecular characterization of the bovine type II IL-1 receptor

The purpose of this study was to clone and characterize the bovine IL-1rII. Using a human IL-1rII probe, three putative exons of the bovine IL-1rII were identified from a bovine genomic library. The full length cDNA for bovine IL-1rII was cloned from a bovine endometrial cDNA library using oligonucleotides designed from those exons. The nucleotide sequence of the bovine IL-1rII cDNA has 79, 69 and 69% identity with those of human, mouse, and rat IL-1rII, respectively. The bovine IL-1rII cDNA contains an open reading frame encoding 400 amino acids with a predicted amino acid sequence of 71, 58, and 59% identity with those of human, mouse and rat IL-1rII, respectively. Transient transfection of COS cells with the cloned bovine IL-1rII cDNA resulted in specific binding of bovine IL-1 beta, with a Kd of 1.82 x 10(-10) M. At least two transcripts of bovine IL-1rII were identified from bovine peripheral blood mononuclear cells (PBMCs), liver, and fetal thymocytes by Northern blot analysis. The relative proportion of these transcripts varied with cell type. In addition, bovine IL-1rII transcripts were detected by RT-PCR in stimulated and unstimulated neutrophils, fibroblasts, and splenocytes. The results of this study provide the first characterization of bovine IL-1rII at a molecular level.

Rabbit DQ52 and DH gene expression in early B-cell development

Rabbits predominantly rearrange the most 3'VH gene (VH1); thus combinatorial diversity is very limited. In man and mouse, the most 3'DH gene, DQ52, is preferentially rearranged early in B-cell development. To test whether this preference for rearranging a DH gene segment based on 3' end proximity exists in rabbit, we cloned and sequenced the rabbit DQ52 gene. The 11 base pair coding region sequence is identical to a published mouse DQ52, and 81.8% similar to the human sequence. It is localized approximately 805 bp upstream of the JH1 gene. However, the 3' recombination signal sequence has an atypical nonamer. We prepared mRNA from 15- to 28-day fetal rabbits and amplified expressed VDJ sequences of mu mRNA by RT-PCR. The PCR products with VDJ rearrangements were cloned and sequenced. As expected, 44 of 45 VDJ sequences reflected use of the 3' VH1a2 gene, but the DQ52 gene was utilized very infrequently, if at all. We found only one VDJ sequence from 28-day fetal liver B-cells with 8 bp that matched the germline DQ52 sequence. Instead of expressing DQ52, another DH gene, Df was frequently expressed. We cloned the genomic Df gene and localized it about 32 kb upstream of the JH region. Thus, in contrast to man and mouse, rabbits preferentially express a DH gene located in the middle of the DH region early in B cell ontogeny. This may correlate with more frequent initial rearrangement of VH to DH in rabbit B cells.

The salvage of a degloved hand skin flap by arteriovenous shunting

Nine cases of hand degloving injuries were treated successfully with arteriovenous shunting technique. Of these nine cases, four were degloved from the wrist level and one from the forearm, three were degloved at the palm and one at the dorsum of the hand. All injuries resulted in distally based skin flaps, which were either superficial to the palmar fascia or within the subcutaneous layer. Lack of active bleeding from the periphery of the avulsed flaps substantiated circulatory compromise before revascularization. Survival of the avulsed flaps was achieved by directing the proximal arterial flow into the venous channel within the avulsed skin flaps. The post-operative care and rehabilitation were straightforward, and functional results were satisfactory.

Effect of ionizing radiation on in vivo striatal release of dopamine in the rat

The time-course effect of ionizing radiation on the levels of basal and KCl-stimulated striatal release of dopamine (DA) was examined in vivo using microdialysis techniques. The basal level of extracellular DA in sham-irradiated controls was 0.172 +/- 0.042 pmol/sample (n = 9), and it increased 7.1-fold after the stimulation by 30 mM KCl (20microliters). However, the release of dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), two metabolites of DA, was reduced significantly by 30 mM KCl (P < 0.05). In the presence of 10 microM forskolin, an activator of adenylate cyclase, a second stimulation by 30 mM KCl increased the release of DA 6.9-fold. Radiation exposure, at a dose of 10 Gy at 10 Gy/min, had no significant effect on the levels of either basal or KCl-stimulated release of DA or on the release of DOPAC and HVA. Striatal DA release increased in response to two consecutive challenges of KCl. However, the release of DA in response to the second challenge of KCl was significantly smaller than that after the first challenge (543 +/- 110% compared to 794 +/- 164%, P < 0.05; Student's paired t test). Pretreatment with 10 muM forskolin, which by itself had no significant effect on the level of basal release of DA, prevented the decreased response of DA to the second challenge of KCl. Our results suggest that radiation exposure at the dose we used has no significant effect on the level of the basal release of DA or the release of DA stimulated by 30mM KCl in the rat striatum, and that a reduced release of DA in response to repeated KCl stimulation might involve the cAMP effector system.

Effect of chloral hydrate on in vivo KCl-induced striatal dopamine release in the rat

The release of striatal dopamine (DA) and its metabolites in response to locally-induced K+ depolarization was investigated in vivo in chloral hydrate-anesthetized and freely moving rats. KCl at concentrations of 30, 50, and 100 mM induced significant dose-dependent increases in extracellular DA overflow in both chloral hydrate-anesthetized and freely moving rats (P < 0.05). Extracellular levels of dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were decreased. The DA overflow in response to 30 mM KCl stimulation in anesthetized rats was significantly greater than that in freely moving rats (P < 0.05). In addition, chloral hydrate anesthesia resulted in a significant decrease in extracellular levels of DOPAC and significant increases in extracellular levels of HVA and 5-HIAA in comparison with freely moving rats (P < 0.05). Furthermore, the basal level of extracellular HVA in chloral hydrate-anesthetized rats was significantly higher than that in freely moving rats. These results suggest that chloral hydrate anesthesia could have significant effects on the pharmacological response of the striatal dopaminergic neurons.