Association between exposure to perfluoroalkyl substances and metabolic syndrome and related outcomes among older residents living near a Science Park in Taiwan

Perfluoroalkyl substances (PFASs) are an emerging class of artificial environmental chemicals that have multiple potentially harmful effects on health. The largest Science Park in Taiwan discharges wastewater containing PFASs into the Keya River, and a high concentration of PFASs has been found in this river and its aquatic creatures. We conducted a cross-sectional study from 2016 to 2017 of 397 subjects aged 55-75 years living near the river and evaluated the association of PFASs with metabolic syndrome and related outcomes. The results indicated that perfluorooctane sulfonate (PFOS) levels were positively associated with serum low-density lipoprotein (LDL) levels (P for trend = 0.03) and that perfluorononanoic acid (PFNA) and PFOS levels were positively correlated with uric acid levels (P for trend = 0.03 and 0.03). Perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA) levels were negatively associated with serum triglyceride levels (P for trend = 0.014 and < 0.01). After excluding lipid-lowering drug users, the association between certain PFAS levels and the LDL level was significantly enhanced, but the downward trends of serum triglyceride levels were weakened. When stratified by sex, PFNA (P for trend <0.01), perfluorohexanesulfonate (PFHxS) (P for trend <0.01), and PFOS (P for trend <0.01) showed positive associations with the uric acid level only among males. In conclusion, our results showed that associations were consistently null between PFASs and metabolic syndrome. PFAS levels were associated with serum lipids, and lipid-lowering drugs may interfere with this relationship. Certain PFASs were found to be positively associated with uric acid levels, especially in males. Further studies are warranted to clarify the causal relationships.

Drug-coated balloon versus conventional balloon angioplasty of hemodialysis arteriovenous fistula or graft: A systematic review and meta-analysis of randomized controlled trials

Background

Restenosis remains a significant problem in endovascular therapy for hemodialysis vascular access. Drug-coated balloon (DCB) angioplasty decreases restenosis in peripheral and coronary artery diseases. The aim of this systematic review and meta-analysis is to assess the patency outcomes following DCB angioplasty, as compared to conventional balloon (CB) angioplasty for the stenosis of hemodialysis vascular access.

Methods

A comprehensive search in the MEDLINE, EMBASE, and CENTRAL databases was conducted in order to identify eligible randomized controlled trials evaluating DCB angioplasty for hemodialysis vascular access dysfunction. The primary endpoint was the 6-month target lesion primary patency and the secondary endpoints were 12-month target lesion primary patency and procedure-related complications. Risk ratios (RR) were pooled and relevant subgroups were analyzed separately.

Results

Eleven randomized controlled trials comprised of 487 patients treated with DCB angioplasty and 489 patients treated with CB angioplasty were included. There were no significant differences in the target lesion primary patency at 6 months [RR, 0.75; 95% confidence interval (CI), 0.56, 1.01; p = 0.06] and at 12 months (RR 0.89; 95% CI, 0.79, 1.00; p = 0.06). The absence of benefit for the DCB group remained, even in the arteriovenous fistula subgroup or the subgroup of studies excluding central vein stenosis. The risk of procedure-related complication did not differ between the two groups (RR 1.00; 95% CI 0.98, 1.02; p = 0.95).

Conclusion

DCB angioplasty did not demonstrate significant patency benefit for the treatment of hemodialysis vascular access dysfunction. Wide variations in patency outcomes across studies were noted. Further studies focusing on specific types of access or lesions are warranted to clarify the value of DCB for hemodialysis vascular access. (PROSPERO Number CRD42019119938)

Cost-effectiveness analysis of universal influenza vaccination: Application of the susceptible-infectious-complication-recovery model

OBJECTIVES

Despite the fact that vaccination is an effective primary prevention strategy for the containment of influenza outbreaks, health policymakers have shown great concern over the enormous costs involved in universal immunization, particularly when resources are limited.

METHODS

A two-arm cost-effectiveness analysis (CEA) was conducted that took into account the aspect of herd immunity. The analysis used a study cohort of 100000 residents with a demographic make-up identical to that of the underlying population in Taipei County, Taiwan, during the epidemic influenza season of 2001-2002. The parameters embedded in the dynamic process of infection were estimated through the application of the newly proposed susceptible-infection-complication-recovery (SICR) model to the empirical data, in order to compute the number of deaths and complications averted due to universal vaccination compared to no vaccination. Incremental cost-effectiveness ratios (ICERs) and the cost-effectiveness acceptability curve (CEAC) given maximum amount of willingness-to-pay (WTP) were calculated to delineate the results of the two-arm CEA.

RESULTS

The incremental costs involved in the vaccinated group as compared to the unvaccinated group were $1195 to reduce one additional complication and $805 to avert one additional death, allowing for herd immunity. The corresponding figures were higher for the results without considering herd immunity. Given the ceiling ratio of WTP equal to $10000 (approximately two-thirds of GDP), the probability of the vaccination being cost-effective for averting death was 100% and for averting complications was 96.7%.

CONCLUSIONS

Universal vaccination against seasonal influenza was found to be very cost-effective, particularly when herd immunity is considered. The probability of being cost-effective was almost certain given the maximum amount of WTP within two-thirds of the GDP.

Helicobacter Pylori Infection is Positively Associated with Metabolic Syndrome in Taiwanese Adults: a Cross-Sectional Study

BACKGROUND

Helicobacter pylori infection and metabolic syndrome have been reported to be positively associated. However, only a few studies have focused on this issue, and H. pylori serum antigen was used to diagnose infection in most of them. We aimed to investigate the association between metabolic syndrome factors and H. pylori infection, as diagnosed via a (13)C-urea breath test.

MATERIALS AND METHODS

This cross-sectional study consisted of 3578 subjects (18-64 years old) enrolled from one health management center between 2008 and 2013. H. pylori infection was defined as a positive urea breath test. The risk of metabolic syndrome from H. pylori infection was assessed using a multiple logistic regression model.

RESULTS

The prevalence of the H. pylori was similar in both genders (20.6% in men and 19.7% in women). H. pylori -infected participants had significantly higher body mass index, fasting glucose, low-density lipoprotein, and triglycerides, and lower high-density lipoprotein (p < 0.05), than uninfected ones (p < 0.05). The prevalence of metabolic syndrome was higher in H. pylori -infected subjects than uninfected ones (men: 12.4% vs. 7.4%, p < 0.001; women: 7.4% vs. 2.5%, p < 0.001). Furthermore, H. pylori infection prevalence increased with metabolic score (P for trend <0.001, both sexes). Moreover, the association between metabolic syndrome and UBT positivity was significant in females (OR 1.91, 95% CI:1.03-3.53), but only borderline significant in males (OR 1.38, 95% CI: 0.97-1.95).

CONCLUSION

H. pylori infection is positively associated with metabolic syndrome, especially in females. The causal relationship between H. pylori infection and metabolic syndrome warrants further investigation.

Carbon dioxide insufflation can significantly reduce toilet use after colonoscopy: a double-blind randomized controlled trial

BACKGROUND AND STUDY AIMS

Carbon dioxide (CO2) insufflation during colonoscopy can significantly decrease abdominal pain and bloating after the procedure, but its impact on the frequency and duration of toilet use remains unknown. The aim of this study was to assess the impact of CO2 insufflation on toilet use after screening colonoscopy.

METHODS

From 138 average-risk individuals who underwent screening colonoscopy during March to August 2013, 120 were enrolled and randomized to receive either CO2 or air insufflation at colonoscopy. Both the colonoscopist and participant were blinded to the type of gas used. Abdominal pain and distension were assessed using a visual analog scoring system. The frequency and duration of toilet visits during a 2-hour postcolonoscopy period were recorded using a radiofrequency identification system.

RESULTS

Baseline characteristics were similar in both groups in terms of age, sex, and procedure time. In the 2 hours after colonoscopy, 50 participants (83 %) in the air group and 18 participants (30 %) in the CO2 group (P < 0.001) used the toilet at least once. The mean (± SD) duration of each toilet visit was 5.93 ± 4.65 minutes in the air group and 1.53 ± 2.84 minutes in the CO2 group (P < 0.001). The abdominal discomfort score was lower in the CO2 group than in the air group both at the end of the colonoscopy (P < 0.001) and 2 hours later (P < 0.001).

CONCLUSION

Insufflation with CO2 can significantly reduce abdominal discomfort and toilet use after colonoscopy. Use of this technique may help reduce patient burden and allow more efficient use of space in the endoscopy unit.

Prediction of lymph node metastasis in T1/T2 tongue squamous cell carcinoma

OBJECTIVES

In T1, T2, and clinically NO squamous cell carcinoma of the tongue, there is no reliable predictive variable to determine whether or not neck dissection is needed. Thus, we established a predictive score model based on tumour depth and other pathological variables.

METHODS

We retrospectively reviewed 115 patients with T1 and T2 stage squamous cell carcinoma of the tongue. Their pathological variables were used to construct a score model for predicting the risk of cervical lymph node metastasis.

RESULTS

A predictive score model was proposed using multivariate logistic regression analysis: Score = (2.694 x tumour depth (cm)) + (1.814 x lymphovascular invasion (yes = 1, no = 0)) + (1.175 x perineural invasion (yes = 1, no = 0)). The cutoff point was set at 2.7427. This predictive score model has a sensitivity of 91.2% and specificity of 65.4%.

CONCLUSION

A predictive score model was built and a two-stage surgical approach was suggested for T1 and T2 squamous cell carcinoma of the tongue.

Increased cancer mortality in Taiwanese inter-island migrants

Higher mortality due to various forms of cancer was observed in emigrants, who had moved from the isolated and impoverished Taiwanese island of Matsu to the more affluent main island. A total of 13,691 ethnic Matsunese aged 30 years and above were enrolled in a study comparing cumulative and standardised mortality rates between emigrants to the main island of Taiwan and those who stayed behind. Poisson regression modelling was used to analyse the effects of migration. For all causes of mortality, the adjusted relative risk was 1.24 with a confidence interval (CI) at the 95% level of 1.08-1.42 for emigrants compared to Matsunese non-emigrants. Deaths from cancer and diabetes in emigrants showed similar results, i.e. an adjusted relative risk of 1.25 (95% CI, 1.00-1.57) and 1.93 (95% CI, 1.20-3.11), respectively. Higher cumulative incidence rates for all cancers and the three leading cancer forms (hepatocellular carcinoma, gastric cancer and lung cancer) in emigrants were also observed. However, no significant difference in the survival time of most of the cancer forms was noted between the two groups. The finding that moving to a more affluent area paradoxically leads to incidence of cancer and higher mortality might be explained by adoption of various forms of unhealthy behaviour, psycho-social factors and the general risks related to life in urbanized environments.

Survivin SNP-carcinogen interactions in oral cancer

In Taiwan, oral cancer is causally associated with environmental carcinogens. Survivin is an anti-apoptotic protein and is generally considered a marker of malignancy. The current study explored the combined effect of survivin gene polymorphisms and environmental carcinogens on the risk and clinico-pathological development of oral cancer. Five single-nucleotide polymorphisms (SNPs) of survivin genes from 439 male patients with oral cancer and 424 male control participants (who did not have cancer) were analyzed. The survivin -31GG, +9194 GG, and +9809 TT homozygotes exhibited higher risk for oral cancer compared with the corresponding ancestral genotype, after adjustment for related confounders. The survivin -31, +9194, and +9809 SNPs combined with betel quid chewing and/or tobacco consumption could robustly elevate susceptibility to oral cancer. The distribution frequency of the -31 G: +9194 A: +9809 T haplotype was significantly higher in oral cancer patients than in control participants. These results suggest that survivin gene polymorphisms and their interactions with environmental carcinogens may increase susceptibility to oral cancer in Taiwanese men.

ABBREVIATIONS

AOR, adjusted odds ratio; CI, confidence intervals; PCR, polymerase chain-reaction; SNP, single-nucleotide polymorphisms.

Cost-effectiveness analysis for Pap smear screening and human papillomavirus DNA testing and vaccination

INTRODUCTION

As the effectiveness of cytology-based screening programme for cervical cancer in mortality reduction has reached a plateau, various preventive strategies have been considered, including intensive Pap smear screening and the supplemental use of human papillomavirus (HPV) DNA test or HPV vaccination. Cost and effectiveness of these various preventive strategies are therefore of great concern for health policy makers.

OBJECTIVE

We intended to assess whether the combination of HPV DNA testing or HPV vaccination with Pap smear screening programme or the sole annual Pap smear screening is more effective and cost-effective in prevention of cervical cancer than the existing triennial Pap smear screening programme.

METHODS

A Markov decision model was constructed to compare total costs and effectiveness between different preventive strategies (including annual Pap smear, HPV DNA testing or HPV vaccination together with Pap smear screening programme) as opposed to the triennial Pap smear screening alone (the comparator). Probabilistic cost-effectiveness (C-E) analysis was adopted to plot a series of simulated incremental C-E ratios scattered over C-E plane and also to yield the acceptability curve for different comparisons of strategies. The threshold of vaccine cost and the influence of attendance rate were also investigated.

RESULTS

Compared with triennial Pap smear screening programme, most of preventive strategies cost more but gain additional life years (quadrant I of C-E plane) except HPV DNA testing with Pap smear every 5 years dominated by triennial Pap smear screening programme. The most cost-effective strategy was annual Pap smear (incremental C-E ratio = $31 698), followed by HPV DNA testing with Pap smear every 3 years ($36 627), and vaccination programme with triennial Pap smear screening ($44 688) with the corresponding cost-effective probabilities by the acceptability curve being 65.52%, 52.08% and 35.84% given the threshold of $40 000 of willingness to pay. Vaccination combined with triennial Pap smear would be as cost-effective as annual Pap smear provided the cost of vaccination was lowered to $250 per full course of injection.

CONCLUSIONS

Among various preventive strategies annual Pap smear screening programme is still the most cost-effective and additional HPV DNA testing is a cost-effective choice under a reasonable threshold of willingness to pay. Vaccination programme in combination with triennial screening would be cost-effective if vaccine cost can be greatly reduced in a large economic scale.

Endoscope-assisted transoral excision of a huge parapharyngeal pleomorphic adenoma

The treatment of choice for a parapharyngeal pleomorphic adenoma is total surgical resection. We describe an endoscope-assisted transoral excision of a huge parapharyngeal pleomorphic adenoma, and discuss the benefits of this type of operation.

Metallothionein-1 genotypes in the risk of oral squamous cell carcinoma

BACKGROUND

We conducted an independent analysis of metallothionein 1 (MT-1) rs8052394, rs11076161, rs8052334, rs964372, rs7191779, and rs708274 in 587 individuals who were either healthy controls or subjects with oral squamous cell carcinoma (OSCC).

METHODS

All participants provided a nucleic acid sample (blood) as well as epidemiologic information on covariates or "risk factors" for OSCC, including tobacco, alcohol, and areca quid use. The genotyping result was used in a logistic regression model that examined main effects as well as statistical interactions while controlling for confounders.

RESULTS

MT-1 is involved in regulation of zinc and copper homeostasis. It also is a potent antioxidant and its polymorphisms correlate with the risk for OSCC. Rs11076161 A, rs964372 C, and rs7191779 C alleles were protective against OSCC (adjusted OR = 0.53, 0.49, 0.36, respectively; p < 0.05), whereas rs8052394 A alleles were associated with increased risk. Areca quid chewing and tobacco use were strong risk factors for developing the disease and were associated with 20- and 8-fold increases in adjusted risk (p < 0.05), respectively.

CONCLUSIONS

Controlling for the effects of age, gender, areca quid, tobacco, and alcohol use, individuals with inherited the MT-1 rs11076161 AA, rs964372 CC, and rs7191779 GC genotypes may experience significant protection against OSCC, whereas individuals carrying the MT-1 rs8052394 A allele seem exposed to higher risk.

A pre-paid newborn hearing screening programme: a community-based study

OBJECTIVES

To help obstetric hospitals and clinics to implement newborn hearing screening and to test the feasibility of a pre-paid model for screening.

PATIENTS AND METHODS

From July 2005 to August 2008, we organised a coordinated newborn hearing screening team with portable automated auditory brainstem response (AABR) to provide in-patient screening after delivery and out-patient re-screening at one month of age in birthing facilities throughout Changhua County, Taiwan. This was a community-based study organised by otolaryngologists at a tertiary referral centre.

RESULTS

Ten medical facilities participated in our screening programme. 7,139 out of 12,901 neonates delivered in these facilities during the period were screened for hearing loss. 105 (1.47%) babies who did not pass the in-patient screening were re-screened at one month old. Forty (0.56%) babies referred from the re-screening were sent for diagnostic work-up and six of them failed to show up. The overall follow-up rate was 94.3% (99/105). Eleven babies with bilateral hearing loss and eight babies with unilateral hearing loss were diagnosed. The incidence of bilateral hearing loss in our programme was 1.5/1000. The screening rate descended from medical centre to clinic (p < 0.0001). There was no significant difference between the referral rates for different levels of birthing facilities (p = 0.5611).

CONCLUSIONS

Our study demonstrates that a pre-paid model using AABR is feasible at all three levels of medical facilities. Pre-paid community-based screening might be an option for developing countries in the implementation of universal newborn hearing screening.

Is planned surgery important in sinonasal inverted papilloma?

OBJECTIVE

To evaluate which clinical characteristics of inverted papilloma (IP) can result easily in misdiagnosis by clinicians and to determine the recurrence rate of inverted papilloma depending on diagnosis confirmation pre-operatively, intra-operatively or post-operatively.

PATIENTS AND METHODS

Fifty-one patients were treated for IP and 47 patients attended regular post-operative follow-up appointments for at least one year (mean: 54 months).

RESULTS

The patients were assigned to 3 groups: group Ia, in which IP was not confirmed until the post-operative pathology findings; group Ib, in which IP was confirmed during the operation; and group II, in which IP was confirmed before the operation. There were nineteen (37%) patients in group Ia, nine patients (18%) in group Ib and twenty-three patients (45%) in group II. The recurrence rates for groups Ia, Ib and II were 33%, 11% and 5% respectively.

CONCLUSIONS

The initial presentation of bilateral sinonasal disease can easily lead the doctor into the misdiagnosis of IP. Bony erosion, remodelling, and a widening of the natural orifice of the sinuses on a CT scan are useful signs indicating IP. The correct diagnosis prior to surgery is a determinant of outcome. The use of frozen sections should, however, improve outcome as well. In this study we highlight the high prevalence and relatively low control rate of misdiagnosed IP (pathology undetermined pre-operatively) and hope to remind clinicians that early recognition of the tumour is most beneficial to patients.

Lethal sphenoid fungal sinusitis in an immunocompromised elderly patient

Sphenoid fungal balls are rare and typically indolent lesions, unless superinfected by bacteria or invasive to adjacent neurovascular structures. If the identification or treatment of underlying complications is delayed in an immunocompromised patient, a catastrophic outcome may result. We report the case of an elderly female patient with poorly controlled diabetes mellitus suffering from sphenoid fungal sinusitis that is complicated by cavernous sinus thrombophlebitis and carotid artery stenosis. In spite of reasonable diagnosis and therapy, the patient's general condition deteriorated and she eventually died. The clinical presentation, diagnosis, and treatment strategy are discussed.

Animal models for intestinal tissue engineering

Although total parenteral nutrition prevents patients with short bowel syndrome from dying of starvation, having short bowel remains a severely debilitating condition. The best current treatment for inadequate absorptive surface area is through intestinal transplantation. However, this therapy is associated with significant morbidity and patients suffer from consequences of long-term immunosuppression. Additionally, the numbers of organs are limited. A new frontier in medicine is the field of tissue engineering. We will review the progress of intestinal bioengineering with a focus on the use of animal models. Investigators initially used autologous tissue as a patch to study intestinal regeneration. Subsequent studies focused on the use of absorbable biomaterials as a patch for tissue ingrowth. The most novel methodology consists of seeding a resorbable scaffold and implanting this construct to observe the regeneration of neointestine. Successful creation of esophagus, stomach, small bowel and colon has been demonstrated. Although these studies are preliminary, the results suggest that tissue-engineered intestine will become a real therapeutic option in the not too distant future for patients with inadequate intestinal tissue.

Primary tumour volume delineation in nasopharyngeal carcinoma and correlation with 1997 AJCC tumour stage classification

OBJECTIVE

To investigate the variability in primary tumour volume in nasopharyngeal carcinoma and compare it with the tumour staging of the 1997 American Joint Committee on Cancer.

DESIGN

Prospective study.

SETTING

Tertiary care centre.

METHOD

A series of 33 newly diagnosed patients who were treated with high-dose radiotherapy participated in the study.

MAIN OUTCOME MEASURES

Using computed tomographic scans, primary tumour volumes were measured using the summation-of-areas technique, and the variability in tumour volume was determined. The Mann-Whitney test was used for statistical analysis.

RESULTS

A large variation in primary tumour volume was observed, especially in advanced-stage cases.

CONCLUSIONS

Nasopharyngeal carcinoma shows considerable variability in primary tumour volume. Incorporation of primary tumour volume may lead to further refinement of the 1997 tumour staging system.

Small bowel tissue engineering using small intestinal submucosa as a scaffold

BACKGROUND

Small intestinal submucosa (SIS) is an extracellular matrix used in tissue engineering studies to create de novo abdominal wall, urinary bladder, tendons, blood vessels, and dura mater. The purpose of this study is to evaluate the feasibility of using SIS as a scaffold for small bowel regeneration in an in situ xenograft model.

MATERIALS AND METHODS

Twenty-three dogs had a partial defect created on the small bowel wall which was repaired with a SIS patch. Four dogs underwent small bowel resection with placement of an interposed tube of SIS. The animals were followed 2 weeks to 1 year.

RESULTS

Three of the 23 dogs with SIS placed as a patch died shortly after surgery due to leakage from the site. The other 20 dogs survived up to time of elective necropsy with no evidence of intestinal dysfunction. At necropsy, the bowel circumference in the patched area had no stenosis. Histological evaluation showed the presence of a mucosal epithelial layer, varying amount of smooth muscle, sheets of collagen, and a serosal covering. Architecturally, the layers were not well organized in the submucosal region. An abundance of inflammatory cells was present in the early postoperative period but receded with time. All 4 dogs with a tubular segment of SIS interposed had significant problems. One had partial obstruction at 1 month, and 3 died in the early postoperative period due to leakage.

CONCLUSIONS

This preliminary study suggests that SIS patches can be used for small bowel regeneration. Tubular segmental replacement is not feasible at this time.

Expression and characterization of monocot rice cytosolic CuZnSOD protein in dicot Arabidopsis

Cytosolic CuZnSOD removes deleterious superoxides from plant cells. In order to understand its function better, we sought to express a monocot CuZnSOD gene in transgenic Arabidopsis. We constructed a transgene using the CaMV 35S promoter to express a rice cytosolic CuZnSOD gene in Arabidopsis and generated over 200 transformants. A 16 kD polypeptide, the same size as the native rice CuZnSOD polypeptide, was detected in the transgenic Arabidopsis. Interestingly, two forms of rice CuZnSOD, rSODI and rSODII, having the same dimeric size, were detected in the transgenic plants. rSODII protein was relatively abundant but had low specific activity. In contrast, rSODI protein was relatively rare and had high specific activity. Inter-conversion of rSODI and rSODII could be achieved by the addition and removal of copper ions into the purified recombinant SOD and to the leaf extract of transgenic plants. Our analysis indicates that rSODI most likely corresponds to native rice CuZnSOD that has incorporated the Cu and Zn ions required for full activity, whereas the less active rSODII form may not have properly incorporated the necessary copper ions.

VEGF is upregulated in a neuroblastoma and hepatocyte coculture model

BACKGROUND

We hypothesize that angiogenic factors are altered by the interaction between neuroblastoma cells and host tissues.

MATERIALS AND METHODS

Human Chang hepatocytes and human neuroblastoma cells are cultured separately and in a noncontact, coculture system. Immunostaining for VEGF is performed on the cells. ELISA is used to detect vascular endothelial growth factor (VEGF), basic fibroblast growth factor, and interleukin-8 in the conditioned media. Human umbilical vein endothelial cells (HUVEC) are cultured with standard medium (control) and hepatocyte, neuroblastoma, and coculture conditioned media. After 48 and 72 h, cells are counted to determine proliferation. Finally, VEGF-blocking antibody is added to the HUVEC cultures with the conditioned media.

RESULTS

VEGF is markedly elevated in the coculture medium compared to the media from hepatocytes or neuroblastoma grown alone [412.2 +/- 52 vs 235 +/- 35 or 74.5 +/- 28.5 (pg/10(6) cells), P < 0.05]. Other growth factors are almost undetectable in any of the media. Immunostaining for VEGF in the cocultured hepatocytes is decreased by almost 50%, but VEGF immunostaining is increased fourfold in the cocultured neuroblastoma cells. A significant increase in cell proliferation is seen at both 48 and 72 h when HUVEC are cultured with the coculture media. Cell proliferation is blocked with the addition of anti-VEGF antibody.

CONCLUSION

The interaction of neuroblastoma with hepatocytes results in an increased production of VEGF. It stimulates endothelial cell proliferation and may enhance the tumor's metastatic potential in an autocrine fashion.

Floral spray transformation can efficiently generate Arabidopsis transgenic plants

In this study, floral spray and floral dip were used to replace the vacuum step in the Agrobacterium-mediated transformation of a superoxide dismutase (SOD) gene into Arabidopsis. The transgene was constructed by using a CaMV 35S promoter to drive a rice cytosolic CuZnSOD coding sequence in Arabidopsis. The transgene construct was developed in binary vectors and mobilized into Agrobacterium. When Arabidopsis plants started to initiate flower buds, the primary inflorescence shoots were removed and then transformed by floral spray or floral dip. More than 300 transgenic plants were generated to assess the feasibility of floral spray used in the in planta transformation. The result indicates that the floral spray method of Agrobacterium can achieve rates of in planta transformation comparable to the vacuum-infiltration and floral dip methods. The floral spray method opens up the possibility of in planta transformation of plant species which are too large for dipping or vacuum infiltration.

Canal-wall-down tympanoplasty with mastoidectomy for advanced cholesteatoma

OBJECTIVE

The objective of this study was to review 8.5 years of the senior author's experience with canal-wall-down mastoid surgery for extensive cholesteatoma with high-grade atelectasis and severely destructed ossicles.

DESIGN

A retrospective review was conducted.

SETTING

The setting was a tertiary care medical centre.

METHODS

Available records consulted included 104 canal-wall-down mastoidectomy for advanced-stage cholesteatomas between July 1984 and December 1992.

MAIN OUTCOME MEASURES

Recurrence, hearing results, and dry ear rate were analyzed.

RESULTS

The recurrence rate was 4 of 104 (3.8%), and 9.6% of subjects suffered from recurrent otorrhea. Thirty-seven of 104 (35.6%) achieved the closure of air-bone gap within 20 dB. The availability of stapes suprastructure influenced the postoperative hearing level significantly (p < .001).

CONCLUSION

Even in treating advanced cholesteatoma, canal-wall-down mastoidectomy provides a low recurrence rate, establishes a high dry ear rate, and preserves adequate hearing when the stapes suprastructure is available for reconstruction.

Free fluid on abdominal computed tomography scan after blunt trauma does not mandate exploratory laparotomy in children

BACKGROUND/PURPOSE

The isolated finding of free intraperitoneal fluid on abdominal computed tomography (CT) scan after blunt trauma in adults is considered an indication for laparotomy by many trauma surgeons. The authors wished to determine if these guidelines are applicable to children.

METHODS

A retrospective chart review was conducted. The authors included all children (< or =12 years of age) sustaining blunt abdominal trauma who were admitted to our institution between January 1, 1994 and November 1, 1998.

RESULTS

There were 814 children admitted, and 437 had abdominal CT scans. Thirty-four studies showed free fluid associated with solid organ injuries, spine or pelvic fractures, or pneumoperitoneum, and were excluded. Thirty-two children had free fluid without associated injuries and formed the basis for the study. Five of these children underwent laparotomy based on the CT finding alone. The remaining 27 were observed with serial abdominal examinations and did not require surgical intervention. Only 1 of the 5 children who underwent surgery for the finding of isolated free fluid had a therapeutic laparotomy. In comparison, during the same period, 38 children underwent laparotomy after blunt injury based only on physical examination findings with a therapeutic laparotomy rate of 68%. The therapeutic laparotomy rate was significantly higher when the procedure was based solely on clinical examination as compared with the isolated finding or free fluid on the abdominal CT (26 of 38 v 1 of 5, P < .05).

CONCLUSION

In contrast to adults, finding isolated free fluid on abdominal CT scans in children after blunt trauma does not dictate immediate surgical exploration.

Neuroblastoma and hepatocyte coculture conditioned media alter apoptosis

BACKGROUND

Neuroblastoma is a childhood tumor that often displays unusual biological behavior. The tumor may present with widespread metastases that are unresponsive to aggressive treatment. At other times, both the metastases and the primary tumor may spontaneously regress without treatment. Apoptosis, or programmed cell death, is thought to play a role in the dichotomous behavior of neuroblastoma. We hypothesize that neuroblastoma cells will interact with host tissues to release mediators that affect apoptosis.

MATERIALS AND METHODS

Human neuroblastoma cells and human Chang hepatocytes are grown in a noncontact, coculture system. After incubation for 4 days, the medium from the coculture system is collected. Neuroblastoma cells and Chang hepatocytes are then plated separately with the conditioned medium and their own standard growth medium as controls. After 4 days, these cells are harvested and cytospins made for immunostaining. Tumor necrosis factor alpha (TNF-alpha), Fas ligand, and Bcl-2, are measured with immunohistochemistry. Apoptosis is detected with the TUNEL method. Immunostaining data are interpreted with computer image analysis and reported as stain index. TUNEL data are reported as percentage apoptotic cells. All data are reported as means +/- SEM. Statistical analysis is performed and P < 0.05 considered significant.

RESULTS

Chang hepatocytes grown in the coculture conditioned media have an increase in TNF-alpha and Fas ligand. The neuroblastoma cells have a significant decrease in Fas ligand. There is a significant increase in the number of apoptotic hepatocytes when they are cultured in the conditioned media. In contrast, the neuroblastoma cells grown in the coculture conditioned media show no increase in apoptosis. Finally, Bcl-2 is significantly increased in the neuroblastoma cells cultured in the conditioned media.

CONCLUSIONS

Neuroblastoma cells grown in coculture conditioned media show increased expression of Bcl-2 and decreased Fas ligand levels. These changes should diminish apoptosis activity in the tumor cells. In contrast, the conditioned media induce elevated levels of proapoptotic mediators in the Chang hepatocytes. A tumor's ability to successfully metastasize may be dependent on mediators generated in the tumor-host interaction, and may not be just an independent characteristic of the tumor itself.

Deep neck infections in diabetic patients

PURPOSE

Deep neck infections may be lethal if life-threatening complications occur, especially in immunocompromised hosts such as diabetic patients. This study was undertaken to better define the clinical features and prognosis of deep neck infections in the diabetic patients with special emphasis on the use of empirical antibiotics and the role and timing of surgical management.

PATIENTS AND METHODS

A retrospective analysis of 105 consecutive patients treated at a single institution during a 9-year period was conducted. Of these, 30 patients also presented with diabetes mellitus.

RESULTS

Compared with the nondiabetic patients, the unique features of deep neck infections in diabetic patients were as follows: (1) older age, (2) tendency of unclear infection source, (3) tendency to involve multiple spaces, (4) required more aggressive surgical intervention, (5) prolonged hospitalization, and (6) higher complication rate. The differences were statistically significant (P< .05). There were no significant differences in the complete blood count/ differential count positive findings and fever between the 2 groups (P> .05). Bacterial cultures showed that Klebsilla pneumoniae was the most common causative pathogen in diabetic patients.

CONCLUSIONS

In deep neck infection patients with diabetes mellitus, the clinical course is more severe and there is a poorer prognosis. Thus, in treating them, we should keep close observation, appropriately control the diabetes, detect the life-threatening complications early, perform aggressive surgical treatment if fluctuation or complication occurs, and take into account the preponderance of K pneumoniae when administering the empirical antibiotics.

Effects of radiotherapy for nasopharyngeal carcinoma on the paranasal sinuses: study based on computed tomography scanning

OBJECTIVE

The purpose of this study was to determine if radiotherapy for nasopharyngeal carcinoma causes mucosal disease of the paranasal sinuses.

DESIGN

This study was a retrospective study.

SETTING

This study was conducted at a tertiary care centre.

METHOD

A series of 69 newly diagnosed patients, without pre-existing sinus disease, who were treated with high-dose radiotherapy participated.

MAIN OUTCOME MEASURES

The prevalence, severity, and time course of mucosal abnormalities were analyzed, as judged by consecutive computed tomographies (CTs).

RESULTS

The CT study revealed that 58.8% of the postirradiation scans had mucosal disease of the sinuses. The maxillary sinus had the highest prevalence (42.3%) without statistical significance (p = .10). The difference by McNemar test for two follow-up scans was not significant (p = .48) and by Kappa test was significant (p = .04). The relationship between the prevalence and the time course post radiotherapy revealed that it remained a high prevalence until after the 4-year follow-up scans.

CONCLUSIONS

The results of this study confirm that chronic sinus disease is a common late complication of radiotherapy and it persists for years. Thus, aggressive treatment is indicated.

Prospective surveillance of children with invasive Haemophilus influenzae disease in Taiwan

During the 16 months from January 1, 1996 through April 30, 1997, forty-three cases of invasive Haemophilus influenzae disease were identified in residents younger than 14 years of age in Taiwan. H. influenzae serotyping was performed on all isolated specimens. There were 33 (76.7%) cases of type b disease; three (7.0%), non-type b, and seven (16.3%), nontypeable cases. Among these H. influenzae type b cases, there were 18 (54.5%) male patients and 15 (45.5%) female patients. With regard to age-distribution, nine (27.3%) patients were aged 2 to 5 years; nine (27.3%), between 1 to 2 years; fifteen (45.5%), younger than 1; and none were younger than 3 months old. Demographical study indicated that 13 patients (39.4%) located in northern Taiwan; 5 (15.2%), central Taiwan; 12 (36.4%), southern Taiwan; 3 (9.0%) from eastern Taiwan. Among the 33 H. influenzae type b cases, twenty-five (75.8%) patients had meningitis and 8 patients had other disease entities, i.e. pneumonia in 4 patients, bacteremia in 3, and cellulitis in 1. In terms of prognosis, three (9.1%) patients died, all of whom having meningitis or sepsis; 7 (21.2%) developed hydrocephalus; 2 (6.1%) had seizure disorder without hydrocephalus and 21 (63.6%) patients recovered completely without sequelae.

Analysis of the costs of surgery for Hirschsprung's disease: one-stage laparoscopic pull-through versus two-stage Duhamel procedure

The purpose of this report is to evaluate the cost-effectiveness of a single-stage laparoscopic pull-through for Hirschsprung's disease compared to the traditional two-stage Duhamel procedure. In this series of 33 children, the length of hospitalization (2.5 +/- 3.5 vs 10.6 +/- 3.9, p < 0.01), cost (19,088 +/- 13,075 vs 34,110 +/- 19,443, p < 0.05), and complications were all significantly less with the laparoscopic assisted pull-through compared to the more traditional open approach.

The effect of leukocyte infiltration on apoptosis in an in vitro thermal injury bioartificial living skin equivalent model

An in vitro bioartificial skin construct (BSC) model was studied to see how inflammatory infiltration affects apoptosis in skin that has been thermally injured. The BSC was used as a target organ. Control BSCs without leukocytes (CON) were burned (BCON) by scalding with phosphate-buffered saline heated to 70 degrees C for 6 seconds, and they were then cooled with room temperature phosphate-buffered saline for 15 seconds. Human alloimmunocytes were added to CON to create rejection cultures (REJ) and to BCON to create burned rejection cultures (BREJ). Slides were stained with hematoxylin and eosin and anti-Lewis antibody. In situ labeling of apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Those sections that were immunostained for Lewis Y were analyzed for intensity stain index (ISI = [sigma P0 x I0]/ total tissue area in pixels). TUNEL was quantified with the following equation: no. of total apoptotic cells / total tissue area. Necrosis and blister formation in the epidermal layer were evident in BCON and BREJ. Pyknosis and nuclear fragmentation-indicators of apoptosis-were also present. Phagocytosis of keratinocytes by leukocytes was seen in REJ and BREJ. Immunostaining showed greater expression of Lewis Y antigen, as determined by ISI, in REJ as opposed to CON (58.2+/-2.3 vs. 36.4+/-2.3, respectively, P<.001), but no significant difference was found between BCON and BREJ (55.0+/-5.7 vs. 60.5+/-3.4, respectively) and REJ and BREJ (58.3+/-2.3 vs. 60.5+/-3.4, respectively). TUNEL staining indicated the presence of apoptosis as follows: REJ versus CON (0.0015+/-0.0002 vs. 0.0003+/-0.0001, respectively, P<.001); BREJ versus BCON (0.0031+/-0.0006 vs. 0.0018+/-0.0004, respectively, P<.05); REJ versus BREJ (0.0015+/-0.0002 vs. 0.0031+/-0.0006, respectively, P = .007). The presence of leukocytes and thermal injury induces apoptosis in BSC. The combination of these two variables results in increased apoptosis as determined by TUNEL. These findings suggest that a common pathway for skin injury may include inappropriate regulation of apoptosis exacerbated by a mechanism that includes inflammatory cellular infiltration.

Varicella arthritis diagnosed by polymerase chain reaction

We report a 2-year-old girl who developed acute arthritis of the left knee 4 days after the onset of a typical varicella infection. She was first thought to have pyogenic arthritis caused by Staphylococcus aureus. Accordingly, oxacillin was administered upon hospitalization. On the third day after hospitalization, bacterial cultures of the synovial fluid and blood showed no growth and oxacillin was discontinued. Although a viral culture of the synovial fluid for varicella-zoster virus (VZV) was negative, varicella DNA was identified by means of polymerase chain reaction (PCR) with VZV-specific primers. The patient recovered spontaneously. To differentiate this condition from septic arthritis is important. PCR is a sensitive technique that can demonstrate the presence of VZV DNA in synovial fluid, even if viral cultures are negative.

Fas-mediated induction of hepatocyte apoptosis in a neuroblastoma and hepatocyte coculture model

BACKGROUND

We have previously demonstrated an increase in hepatocyte apoptosis when they are cocultured with neuroblastoma cells. Death receptors in the tumor necrosis factor (TNF) family such as TNFR1 and Fas have been identified as regulators of apoptosis and may be responsible for the altered regulation of apoptosis seen in our coculture model. To evaluate the effects of released factors and remove the potential alterations induced by direct contact, a noncontact coculture system was used to study the interaction between hepatocytes and neuroblastoma cells.

METHODS

Human Chang hepatocytes (HC) were plated onto Falcon cell culture inserts with 0.45-micrometer pores in the permeable membrane. Human neuroblastoma cells (NB-IMR-32) were seeded into wells of the Falcon companion plate. After 24 h, inserts containing HC were placed into wells containing NB cells and incubated for 4 days. This provided a coculture environment without actual cellular contact. Immunohistochemical staining for TNFalpha, Fas, and Fas ligand (Fas-L) was performed. Apoptosis was detected via the TUNEL method. Images were analyzed with ImagePro-Plus. Statistical analyses were done with significance determined at P < 0.05.

RESULTS

Chang hepatocytes demonstrated a significant increase in the levels of TNF, Fas, and Fas-L when cocultured with neuroblastoma cells (P < 0.005). In addition, the cocultured hepatocytes had a 20-fold increase in the apoptotic rate (P < 0.001). Neuroblastoma cells had no demonstrable level of Fas or TNF when grown alone and in cocultures. Neuroblastoma cells that were grown alone had an elevated level of Fas-L, but this level diminished by 44% when cocultured with hepatocytes (P < 0.001).

CONCLUSION

An upregulated TNF/Fas receptor-ligand system may be responsible for increased apoptosis in hepatocytes when cocultured with neuroblastoma. This upregulation may be due to release of neuroblastoma-derived Fas ligand into the media. Tumors may alter the regulation of apoptosis in surrounding tissues via the death receptors.

Induction of apoptosis in a neuroblastoma and hepatocyte coculture model

BACKGROUND

The dysregulation of apoptosis may alter the progression of tumor growth and explain the clinical dichotomy observed in children with neuroblastoma (NB). An overexpression of the bcl-2 proto-oncogene induces resistance to apoptosis and has been observed in unfavorable NB. We hypothesized that alterations in apoptosis may be a result of the interactions between NB and the tissues surrounding it.

MATERIALS AND METHODS

Human Chang liver cells (HCL, 10(4) cells/cm2) were plated in two-chamber slides for 3 days. Human NB cells (10(5) cells/cm2) were added to one of the chambers and incubated for 3 more days. Control NB were plated under identical conditions in its own medium and in the HCL medium with growth curves measured. DNA fragmentation was detected via the TUNEL method (TdT-mediated nick end-labeling) and bcl-2 expression was determined by immunostaining.

RESULTS

NB growth was unaltered by the change in medium. NB stained mildly positive for bcl-2 when plated alone but became markedly positive in coculture. Histologically, HCL and NB appeared healthy when plated alone, but a halo of apoptotic HCL was seen around NB in the coculture. When plated alone, both NB and HCL demonstrated minimal apoptotic activity as detected via the TUNEL method. In the coculture, a halo of HCL surrounding the NB exhibited markedly increased DNA fragmentation and this intensity diminished in cells distant from the NB.

CONCLUSIONS

The regulation of apoptosis was altered in this coculture model of NB and HCL. HCL stimulated NB to overexpress bcl-2 and presumably become resistant to apoptosis. Conversely, NB induced the surrounding HCL to undergo apoptosis. The interaction between the local tissue and NB induced alterations in apoptosis in both cell types and resulted in a survival advantage for NB.

Predisposing factors of life-threatening deep neck infection: logistic regression analysis of 214 cases

OBJECTIVE

In the era of antibiotics, most deep neck infections can be cured by conservative treatment, but some still result in life-threatening complications. In this study, we discuss whether or not there are predisposing factors of complicated deep neck infection.

DESIGN

A retrospective chart review of patients presenting between 1988 and 1996 was conducted.

METHOD

Among 214 deep neck infection patients, 18 cases resulted in lethal complications. We used the "dummy" variable with logistic regression as the statistical analysis method.

RESULTS

Patients with an underlying disease, neck swelling, and delay time had a positive correlation that was statistically significance (p < .05). Patients who were older, male, with complete blood count/differential count-positive finding and fever had positive correlation, but this was not statistically significant (p > .05).

CONCLUSION

Although complicated deep neck infection is a rapidly progressive disease with a high mortality, we can not thoroughly predict the prognosis or avoid it happening completely. But, if we can detect and pay more attention to the high-risk group of patients with use of aggressive therapy, the incidence of complicated deep neck infection may be reduced.

The secreted hepatitis B precore antigen can modulate the immune response to the nucleocapsid: a mechanism for persistence

The hepatitis B precore Ag (HBeAg) is a secreted nonparticulate version of the viral nucleocapsid hepatitis B core Ag (HBcAg), and its function is unknown. A proportion of HBeAg-specific Th cells evade deletion/anergy in HBeAg-transgenic (Tg) mice and mediate anti-HBe "autoantibody" (autoAb) production after in vivo activation with the appropriate Th cell peptide. This model system was used to determine how secretory HBeAg may effect deletion of Th cells in the periphery. For this purpose, HBeAg-Tg mice were bred with Fas and Fas ligand (FasL)-defective lpr/lpr and gld/gld mutant mice. Fas-FasL interactions mediate activation-induced apoptosis in the periphery. In HBeAg-Tg/+ mice, high-titrated anti-HBe autoAb was produced that was exclusively composed of the IgG1 isotype (i.e., Th2-like profile). In contrast, HBeAg-Tg/lpr and HBeAg-Tg/gld mice produced significantly less anti-HBe autoAb, and the IgG isotype patterns were broadened to include IgG2a, IgG2b and IgG3 as well as IgG1 (i.e., mixed Th1/Th2-like profile). These results suggest that HBeAg-specific Th1 cells are preferentially depleted by Fas-FasL-mediated interactions. The effect of circulating HBeAg on HBcAg-specific Th1 cells was also examined by transferring HBe/HBcAg-specific Th cells into dual HBeAg- and HBcAg-expressing Tg recipient mice. The presence of serum HBeAg ablated the expected Th1-mediated anti-HBc Ab response and shifted it toward a Th2 phenotype. These results suggest that in the context of a hepatitis B viral infection, circulating HBeAg has the potential to preferentially deplete inflammatory HBeAg- and HBcAg-specific Th1 cells that are necessary for viral clearance, thereby promoting hepatitis B virus persistence.

Infradiaphragmatic extralobar pulmonary sequestration masquerading as an intra-abdominal, suprarenal mass

Three infants were found to have infradiaphragmatic masses by prenatal ultrasound. Postnatal imaging studies confirmed the presence of these masses, which were suspected of being intra-abdominal malignancies (neuroblastoma). The other principal differential diagnosis was extralobar pulmonary sequestration (EPS). Intraoperative findings were consistent with EPS, which was confirmed by histologic examination. We present these three infants, review the literature, and discuss the evaluation and treatment of infradiaphragmatic EPS.

Perinatal management of enteric duplication cysts of the tongue

Intra-oral enteric duplication cysts are rare. We recently treated two infants with prenatally diagnosed large sublingual enteric duplication cysts. Antenatal aspiration of the cyst was attempted in one infant without success. Because of the potential for airway obstruction and respiratory distress at delivery, preparation for an immediate tracheostomy was made in case oral intubation was impossible. Fortunately, aspiration of the cyst provided adequate access to the oropharynx for intubation in both infants. The placental cord was not divided until the airway was secured to minimize the potential for anoxic injury. Complete excision of the cyst was subsequently done in one patient. The other infant had an initial marsupialization and laser ablation of the cyst mucosa but the cyst recurred. Cyst excision at 9 months of age resolved the problem. Pathological examination revealed columnar-lined mucosa consistent with enteric duplication cysts. An enteric duplication cyst may present as a large sublingual mass with potential for airway obstruction in the newborn infant. Antenatal diagnosis allows for the proper preparation of personnel and equipment in the management of these neonates during delivery. If the airway is compromised, aspiration of the cyst can be done to improve the access to the oropharynx for intubation. Preparation for emergent tracheostomy should be done before delivery in case oral intubation is not possible. Subsequent complete cyst excision is the treatment of choice.

Laparoscopic common duct exploration in a child with recurrent pancreatitis due to a primary fungus ball in the terminal common bile duct

We report on a case of a fungus ball obstructing the distal common bile duct and causing recurrent pancreatitis in an otherwise healthy 3-year-old boy. Laparoscopic exploration of the common bile duct was performed using a 10 french rigid fiberoptic cystoscope and a Dormia basket. This is the first example of a primary fungus ball in common bile duct presenting as a pancreatitis and treated laparoscopically.

Tracheal hamartoma: report of a child with a neck mass

Tracheal hamartoma represents an oddity in children. Only one case was found in the English literature as a distal tracheal intraluminal lesion causing obstructive symptoms. All other reported cases were in older patients, who were presumed to have asthma or chronic obstructive pulmonary disease. The authors report on a 21-month-old girl who presented with an anterior neck mass fixed to the trachea. Imaging studies showed a lesion (2.5 x 2.3 x 1.7 cm) anterior to the right lobe of the thyroid, extending to the trachea posteriorly and down to the thoracic inlet inferiorly. The mass had a mixture of soft tissue densities with a focus of calcification. Results of thyroid studies were normal, and there was no adenopathy. Neck exploration showed a white, firm, lobulated mass fixed to the trachea, which was resected completely. The postoperative course was unremarkable. Histological studies showed a mixture of mature cartilage, fat, fibroconnective tissue, and spindle cells with myxoid degeneration, consistent with tracheal hamartoma. Based on a literature search, this is the first reported case of extraluminal tracheal hamartoma presenting as a neck mass in a pediatric patient.

Laparoscopic evaluation and treatment of intestinal malrotation in infants

Infants with intestinal malrotation present with bilious emesis and the diagnosis is generally obtained by an upper gastrointestinal barium study. Malrotation is suspected if the ligament of Treitz is not positioned to the left of the vertebral body. Barium enema may also be used to detect malrotation by noting the abnormal position of the cecum from its usual placement in the right lower quadrant, but this study is not as reliable due to the mobility of the cecum. Some infants may not have classic radiographic findings for malrotation, yet the contrast studies are not entirely normal. We recently treated two infants with recurrent vomiting whose UGI studies suggested intestinal malrotation. Laparoscopic exploration confirmed the diagnosis of malrotation. Laparoscopic correction (Ladd's procedure) of malrotation was carried out in one infant. The second infant underwent a traditional Ladd's procedure. The technique of laparoscopic Ladd's procedure is described. Laparoscopy may be used for the diagnosis and treatment of infants with intestinal malrotation. It may be especially helpful to verify the diagnosis in patients who do not have classic radiographic findings. Whether laparoscopy should be used in patients with midgut volvulus is debatable. Laparoscopic derotation of the volvulus in a setting where the bowel is markedly distended may be difficult and dangerous.

Complications of minimal-access surgery in children

Minimal-access surgery (MAS) is rapidly becoming the surgical approach of choice for a variety of surgical disorders in adults, but its use in children remains a relative novelty. Most pediatric surgeons continue to harbor justifiable concerns about the morbidity of this modality owing to the cumbersome nature of the instruments and the technical difficulty associated with two-dimensional views. The purpose of this study was to determine the complication rate and the lessons learned from the use of MAS in performing a variety of procedures in a large series of children. To determine complications, the authors reviewed the medical records of all children (n = 636; age range, 1 month to 19 years) who underwent laparoscopy (LAP) or thoracoscopy (THO) during a 5-year period (January 1, 1990 through December 31, 1994). The follow-up ranged from 1 week to 45 months. THO was performed in 62 children. Conversion to thoracotomy occurred in eight children (13%), because of inability to localize the lesion (3), unresectibility (2), inadequate tissue sample (1), unsafe access (1), hypoxemia (1), or inadvertent esophagotomy (1). Postoperatively, two ventilator-dependent children had tension pneumothorax after lung resection and required chest tubes. LAP was performed on 574 children, with conversion to laparotomy occurring in 15 (2.6%), because of technical reasons (10) or intraoperative complications (5). The complication rate of LAP was 2% (12 of 574). Early in the experience, intraoperative complications that led to laparotomy included hemorrhage during appendectomy (2), cholecystectomy (1), and splenectomy (1); and esophagotomy during a fundoplication (1). Other technical problems in the postoperative period were a malpositioned Nissen fundoplication and a gastric volvulus after gastrostomy and Nissen fundoplication owing to improper gastrostomy tube position. In addition, two children had a hernia at the umbilical trocar site that had been used for contralateral inguinal exploration, and cellulitis developed in three patients when a gastrostomy tube was brought out through a trocar site. Other complications not specific to MAS included pelvic abscess after appendectomy (5); small bowel obstruction after jejunostomy catheter placement (1) and combined cholecystectomy/appendectomy (1); enterocolitis (1) and severe hyponatremia (1) after pull-through for Hirschsprung's disease; and pneumonia after splenectomy (1). The overall complication rate of MAS was 4% (26 of 626), and there were no deaths. The initial use of MAS was associated with technical errors, which decreased with experience. Based on this study, the authors recommend (1) routine placement of a thoracostomy tube in children after THO if they require postoperative ventilator support; (2) using the open hernia sac to place a 70 degrees telescope for contralateral inguinal exploration; and (3) not using a trocar site for gastrostomy tube placement in immune-suppressed patients. With appropriate training and experience, MAS can be used safely in children, for a wide variety of diseases, with minimal morbidity and mortality.

The use of minimal access surgery in pediatric trauma: a preliminary report

Minimal access surgery (MAS) is becoming an accepted modality in the management of adult trauma, but its use in children is rarely reported. Recently, we began using minimal access surgery to evaluate injured children. The purpose of this report is to review our preliminary experience with the use of laparoscopy and thoracoscopy in blunt and penetrating pediatric trauma. Eight children aged 2-14 years old were evaluated using MAS. Two children with blunt injuries had persistent abdominal pain despite normal radiologic studies. Laparoscopy documented a disrupted gallbladder and a small bowel perforation. Laparoscopy was also used to evaluate five hemodynamically stable children with penetrating wounds to the abdominal wall with potential peritoneal penetration. Only one child was converted to a laparotomy. Four were found to have either tangential penetrating wounds or nonbleeding solid organ injuries and were spared an open exploration. Two children with penetrating trauma with potential mediastinal injury were assessed with thoracoscopy. MAS was also used as a therapeutic modality in two children who had diaphragmatic lacerations repaired with an endoscopic "hernia" stapler. MAS accurately identified all injuries. All children were subsequently discharged without complications. We conclude that MAS is a safe and effective way to evaluate and manage hemodynamically stable children with both penetrating and blunt traumatic injuries.

Influence of progressive tumor growth on glutamine metabolism in skeletal muscle and kidney

OBJECTIVE

The effects of progressive malignant growth on glutamine metabolism in skeletal muscle and in kidney were investigated.

SUMMARY BACKGROUND DATA

Fast-growing tumors consume considerable quantities of glutamine and lead to a decrease in circulating glutamine concentrations.

METHODS

Experiments were performed at various stages of tumor growth in rats implanted subcutaneously with the non-metastasizing methylcholanthrene-induced (MCA) fibrosarcoma and in pair-fed non tumor-bearing controls.

RESULTS

Tumor growth stimulated a twofold increase in hindquarter (muscle) glutamine release, which was not due to an increase in blood flow, but rather to a doubling in the fractional release rate. Consequently, a progressive decrease in skeletal muscle glutamine concentrations was observed over time. Simultaneously, the activity of glutamine synthetase (GS), the principal enzyme of de novo glutamine biosynthesis, increased more than twofold. This increase in muscle GS activity was accompanied by an increase in GS mRNA but the augmentation in GS expression apparently could not match the increased rate of efflux since muscle depletion developed. In rats with large tumors and severe glutamine depletion, GS activity was not elevated. Glutamine feeding increased muscle glutamine concentrations and glutamine synthetase specific activity. Although tumor growth led to the development of mild systemic acidemia, the classic renal adaptations normally observed, i.e., elevated glutaminase activity and accelerated renal glutamine utilization, were not present in acidotic tumor-bearing rats. Instead, renal GS activity was increased in tumor-bearing animals and ammoniagenesis was enhanced, in spite of a reduction in net renal glutamine uptake.

CONCLUSIONS

These data suggest that marked alterations in muscle and renal glutamine handling occur in the host with cancer; the enhanced muscle glutamine release in conjunction with no increase in renal consumption is consistent with increased glutamine uptake in other organs, most likely the tumor itself and the liver.

Adaptive Regulation in Skeletal Muscle Glutamine Metabolism in Endotoxin-Treated Rats

The effects of a single dose of endotoxin (7.5 mg/kg BW) on skeletal muscle glutamine metabolism were studied in vivo in rats to gain further understanding of the altered glutamine metabolism that characterizes sepsis and other catabolic diseases. In endotoxin-treated animals the arterial glutamine concentration fell early initially and then increased compared with control values. Twelve hours after treatment, the arteriovenous concentration difference for glutamine across the hindquarter doubled, resulting in a significant increase in net muscle glutamine release in endotoxin-treated rats. As a consequence, the muscle glutamine concentration fell in the endotoxin-treated animals by 25%-40%, an event that was apparent as early as two hours after endotoxin treatment. Skeletal muscle glutaminase activity, the major enzyme of glutamine breakdown, was unchanged by endotoxemia, but expression of glutamine synthetase mRNA and glutamine synthetase specific activity increased in a time-dependent fashion. The glutamine depletion that develops in skeletal muscle during endotoxemia is caused by accelerated muscle glutamine release rather than an increase in intracellular degradation or a fall in intracellular biosynthesis. The adaptive increase in glutamine synthetase expression that occurs requires de novo RNA and protein synthesis and may be designed to prevent complete depletion of the intracellular glutamine pool.

Mechanisms of accelerated hepatic glutamine efflux in the tumour-bearing rat

The mechanisms potentially controlling the net release of glutamine by the liver that occurs in tumour-bearing rats were investigated. Studies were undertaken when the tumour comprised approximately 7% (15 +/- 2 g) of total body weight. Hepatic glutamine gradient ratios were calculated by dividing hepatic glutamine content by arterial blood glutamine concentration. Both sodium-dependent and sodium-independent hepatocyte carrier-mediated glutamine transport were evaluated employing hepatic plasma membrane vesicles (HPMVs). In TBR the hepatic glutamine gradient ratio doubled (P < 0.001) secondary to a 52% increase in hepatic content (P < 0.005) and a 16% decrease in circulating glutamine (P < 0.001). Sodium-dependent glutamine transport was increased in HPMVs from TBR secondary to a 24 +/- 4% increase in the maximal velocity of transport (Vmax; P < 0.01) without alteration in apparent transporter affinity (Km). Saturable sodium-independent carrier-mediated glutamine transport was increased in HPMVs from TBR over CONT to a much greater relative degree owing to a 2.7-fold increase in transport Vmax (P < 0.05) without a change in transport Km. The accelerated hepatic efflux of glutamine which characterizes malignant growth appears to be the result of both mass-action gradient phenomena and alterations at the level of hepatocyte membrane transport activity.

Cytokine regulation of intestinal glutamine utilization

The effects of cytokines on intestinal glutamine metabolism were studied to gain further insight into the regulation of altered glutamine metabolism that occurs during severe infection. One hundred thirteen adult rats were given a single dose of interleukin-1 (IL-1, 50 micrograms/kg), tumor necrosis factor (TNF, 50 micrograms/kg or 150 micrograms/kg), or saline (controls), and flux studies were performed 4 or 12 hours later. Intestinal blood flow was not different between control and cytokine-treated animals at either time point. At the 4-hour time point, arterial glutamine fell by 16% to 21% in the cytokine-treated animals (p less than 0.05); at the 12-hour time point, the arterial glutamine concentration had returned to normal. Intestinal glutamine extraction decreased in the animals treated with IL-1 at both time points (4 hours: 13% +/- 1.3% in IL-1 versus 20% +/- 1.6% in controls, p less than 0.05; and 12 hours: 9% +/- 2% in IL-1 versus 17% +/- 2% in controls, p less than 0.05). Consequently, net intestinal glutamine uptake fell in the animals treated with IL-1 at both time points (p less than 0.05). Similarly, the activity of mucosal glutaminase, the principal enzyme of glutamine hydrolysis in the gut, fell by 50% in the 4-hour study (6.1 +/- 0.6 mumol/h/mg protein in IL-1 versus 9.6 +/- 0.8 mumol/h/mg protein in controls, p less than 0.01) and by 40% in the 12-hour study (5.4 +/- 0.5 mumol/h/mg protein in IL-1 versus 8.8 +/- 0.4 mumol/h/mg protein in controls, p less than 0.05). Concomitant with the aforementioned decrease in gut glutamine metabolism was a 25% incidence of positive blood cultures for gram-negative organisms in IL-1 treated rats studied at the 12-hour time point (p = 0.05 versus controls). In the doses administered and at the time points studied, TNF had no effects on the parameters of gut glutamine metabolism examined. The results indicate that IL-1 is a potential mediator of the alterations in gut glutamine metabolism observed in sepsis and endotoxemia.