Effect of Fumigation on Rotylenchulus reniformis Population Density Through Subsurface Drip Irrigation Located Every Other Furrow

Plots naturally infested with Rotylenchulus reniformis were sampled in the spring of 2006 and 2007 at depths of 15 and 30 cm in the bed, furrow over the drip tape, and "dry" furrow, and at approximately 40 to 45 cm depth in the bed and dry furrow. Then, 1,3-dichloropropene (Telone EC) was injected into the subsurface drip irrigation at 46 kg a.i./ha, and 3 to 4 weeks later the plots were resampled and assayed for nematodes. The transformed values for nematode population density (IvLRr) before fumigation were higher at 30 and 40 cm depths than at a 15 cm depth. IvLRr before fumigation was higher in the soil over the drip lines than in the bed or dry furrow and was higher in the bed than the dry furrow. IvLRr was higher in the plots to be fumigated than the plots that were not to be fumigated for all depths and locations except at a 15 cm depth over the drip lines, where the values were similar. However, after fumigation, IvLRr was lower over the drip lines at a 30 cm depth in plots that were fumigated compared to samples in a similar location and depth that were not fumigated. There were no other location/depth combinations where the fumigation reduced IvLRr below that in the nonfumigated plots. Yield in 2006, which was a very hot and dry year, was predicted adequately (R(2) = 0.67) by a linear model based on the preplant population density of R. reniformis, with a very steep slope (-2.8 kg lint/ha per R. reniformis/100 cm(3) soil). However, no relationship between nematode density and yield was seen in 2007, which had cooler weather for most of the season. Yield was not significantly improved by fumigation through the drip irrigation system in either year compared to plots treated only with aldicarb (0.84 kg a.i./ha), indicating that the level of control with fumigation did not kill enough R. reniformis to be successful.

Association between polymorphisms of the GPX1 gene and second primary tumours after index squamous cell cancer of the head and neck

We investigated the association between genetic polymorphisms in GPX1 gene amongst patients who had index squamous cell carcinoma (SCCHN) and a second primary tumour (SPT) after a primary SCCHN in a case-control study. GPX1 genotypes were determined for 61 patients with SPT and for 259 control subjects by a PCR technique using a fluorescent-labelled primer. Analysis was by an ABI automated fluorescent sequencer. The associations between specific genotypes and the development of SPT were examined by logistic regression. A significant difference was found between the control group and the SPT cases in allele frequencies of GPX1 ALA( *)6 and ALA( *)7 (p(trend)=0.04). These results suggest that polymorphisms in the GPX1 gene may be a marker for SPT development and further studies are indicated.

Tumour thickness predicts cervical nodal metastases and survival in early oral tongue cancer

Squamous cell carcinoma (SCC) of the oral tongue is characterized by a high propensity for cervical nodal metastasis, which affects the probability of regional control and survival. Until now, elective treatment of the clinically negative neck in early lesions (T(1-2)) of the oral tongue cancer remains controversial. This study attempted to identify predictive factor(s) for cervical nodal metastasis and treatment outcomes in patients with early stage SCC of the oral tongue treated primarily by surgery. Fifty patients with previously untreated Stage I/II primary tongue carcinomas with available archival specimens treated at the Royal Marsden Hospital between 1981 and 1998 were reviewed. Clinico-pathological features including age, gender, alcohol and tobacco consumption, tumour location, histological grade, tumour-stromal border, growth pattern, tumour thickness, and clinical stage were evaluated and the correlations with cervical metastases and outcome analysis were determined. The overall occult nodal metastatic rate was 40% (20/50). Tumour thickness exceeding 5 mm was statistically significantly correlated with cervical metastases (P = 0.003; relative risk = 2.429). No statistical correlation was observed between other clinico-pathological parameters and nodal metastasis. With a median follow-up of 98 months, 5-year actuarial overall, disease-specific (DSS), and relapse-free survival were 65.71, 67.77, and 68.18%, respectively. Univariate analysis for DSS showed poorer outcomes for patients with age > 60 years (P = 0.0423) and tumour thickness > 5 mm (P = 0.0067). The effect of tumour thickness was maintained (P = 0.005) on multivariate analysis. The present study indicates that the thickness of primary tumour has a strong predictive value for occult cervical metastasis and poor outcomes in patients with Stage I/II oral tongue SCC. Thus, elective neck treatment (surgery or irradiation) is indicated for tumours exceeding 5 mm thickness.

Mucosal malignant melanoma of the head and neck: the Marsden experience over half a century

We reviewed patients treated at The Royal Marsden Hospital for mucosal malignant melanoma of the head and neck between 1945 and 1996. The analysis included 89 patients, and this study is the largest so far reported from a single institution in the literature. The overall 5-year survival rate for the patient population was 23% (95% confidence interval: 14-33) and the 10-year survival rate was 12%, (6-21%). The only significant predictor of survival was the tumour stage at presentation. Radical local excision was the only treatment that provided a chance of cure. Adding radiotherapy to surgery in tumours that could be radically excised did not confer any statistically significant advantage in reducing local recurrence or improving survival.

Factors affecting microbial formation of nitrate-nitrogen in soil and their effects on fertilizer nitrogen use efficiency

Mineralization of soil organic matter is governed by predictable factors with nitrate-N as the end product. Crop production interrupts the natural balance, accelerates mineralization of N, and elevates levels of nitrate-N in soil. Six factors determine nitrate-N levels in soils: soil clay content, bulk density, organic matter content, pH, temperature, and rainfall. Maximal rates of N mineralization require an optimal level of air-filled pore space. Optimal air-filled pore space depends on soil clay content, soil organic matter content, soil bulk density, and rainfall. Pore space is partitioned into water- and air-filled space. A maximal rate of nitrate formation occurs at a pH of 6.7 and rather modest mineralization rates occur at pH 5.0 and 8.0. Predictions of the soil nitrate-N concentrations with a relative precision of 1 to 4 microg N g(-1) of soil were obtained with a computerized N fertilizer decision aid. Grain yields obtained using the N fertilizer decision aid were not measurably different from those using adjacent farmer practices, but N fertilizer use was reduced by >10%. Predicting mineralization in this manner allows optimal N applications to be determined for site-specific soil and weather conditions.

Silicone oil-intraocular lens interaction: which lens to use?

AIM

To determine a suitable intraocular lens for implantation in patients at high risk of lens exposure to silicone oil in their lifetime.

METHODS

PMMA, AcrySof, AR40, AQUA-Sense, and Raysoft lenses were examined. Each lens was immersed for 5 minute intervals in balanced salt solution (BSS), in stained silicone oil, and again in BSS before being photographed in air and in BSS. Percentage silicone oil coverage of the lens optic was determined.

RESULTS

The mean percentage coating (MPC) for the lens biomaterials ranged from 5.2% to 21.5%. The Raysoft lens had significantly less oil coverage when statistically compared with the other lens types (p < 0.001).

CONCLUSION

A Raysoft (Rayner) lens is a suitable lens for implantation in patients who are at risk of severe vitreoretinal disease.

Alcohol oxidase is a novel pathogenicity factor for Cladosporium fulvum, but aldehyde dehydrogenase is dispensable

Cladosporiumfulvum is a mitosporic ascomycete pathogen of tomato. A study of fungal genes expressed during carbon starvation in vitro identified several genes that were up regulated during growth in planta. These included genes predicted to encode acetaldehyde dehydrogenase (Aldh1) and alcohol oxidase (Aox1). An Aldh1 deletion mutant was constructed. This mutant lacked all detectable ALDH activity, had lost the ability to grow with ethanol as a carbon source, but was unaffected in pathogenicity. Aox1 expression was induced by carbon starvation and during the later stages of infection. The alcohol oxidase enzyme activity has broadly similar properties (Km values, substrate specificity, pH, and heat stability) to yeast enzymes. Antibodies raised to Hansenula polymorpha alcohol oxidase (AOX) detected antigens in Western blots of starved C. fulvum mycelium and infected plant material. Antigen reacting with the antibodies was localized to organelles resembling peroxisomes in starved mycelium and infected plants. Disruption mutants of Aox1 lacked detectable AOX activity and had markedly reduced pathogenicity as assayed by two different measures of fungal growth. These results identify alcohol oxidase as a novel pathogenicity factor and are discussed in relation to peroxisomal metabolism of fungal pathogens during growth in planta.

A randomized comparison of the effects on vaginal and cervical epithelium of a placebo vaginal ring with non-use of a ring

Little is known about the effects of contraceptive vaginal rings on the vaginal surface epithelium, although most studies have not demonstrated any significant deleterious effect. However, one study found that some medium-to-long-term levonorgestrel-releasing ring users developed chronic erythematous and ulcerative lesions in the posterior vaginal fornix. Subsequently, this ring was completely redesigned (IVR-2) with different dimensions and much greater flexibility. The first version of IVR-2 was designed as a placebo ring to explore effects on the vagina and cervix without addition of a progestogen. One-hundred-sixty-six healthy sexually active women volunteers were recruited in four centers and randomly assigned for 6 months to either placebo ring use or control (non-use) using a predetermined randomization code generated by WHO in a 2:1 ratio. Careful inspections of the vaginal and cervical epithelium were performed with a colposcope at admission and at 2-month intervals. No clinically significant lesions were detected in any center either among ring users or controls. However, a number of minor changes in appearance of the vaginal and cervical epithelium (erythema, petechiae, ecchymosis, and minor aceto-white changes) were described from the Sydney Center, some of which were present on admission and some of which were found on subsequent examination. Ten of eleven "red" changes on the cervix and vagina were noted in IVR-2 users, and only one in the controls, suggesting a contribution by the IVR-2 to minor epithelial surface changes. Five of ten resolved completely with continued ring use. There was no correlation in this study between epithelial changes and cigarette smoking or frequency of intercourse in the 14 days prior to colposcopic examination but a significant relationship between tampon use in the last 7 days and all epithelial changes (p = 0.05) and especially red changes (p = 0. 027) was noted. Red changes were significantly less likely to be found among condom users (p = 0.007). The IVR-2 placebo ring did not produce clinically significant changes in the vaginal epithelium and cervical mucosa and a carefully controlled and randomized study should be considered to compare the epithelial appearances in women using a placebo IVR-2 and one releasing 20 microg levonorgestrel.

Plant low-molecular-weight phospholipase A2S (PLA2s) are structurally related to the animal secretory PLA2s and are present as a family of isoforms in rice (Oryza sativa)

Recently, we purified to homogeneity and characterized a low-molecular-weight calcium-dependent phospholipase A2 (PLA2) from developing elm seed endosperm. This represented the first purified and characterized PLA2 from a plant tissue. The full sequences of two distinct but homologous rice (Oryza sativa) cDNAs are given here. These encode mature proteins of 1 19 amino acids (PLA2-I, preceded by a 19 amino acid signal peptide) and 128 amino acids (PLA2-II. preceded by a 25 amino acid signal peptide), and were derived from four expressed sequence tag (EST) clones. Both proteins were homologous to the N-terminal amino acid sequence of the elm PLA2. They contained twelve conserved cysteine residues and sequences that are likely to represent the Ca(2+)-binding loop and active-site motif, which are characteristic of animal secretory PLA2s. A soluble PLA2s activity was purified 145 000-fold from green rice shoots. This had the same biochemical characteristics as the elm and animal secretory PLA2s. The purified rice PLA2 consisted of two proteins, with a molecular weight of 12 440 and 12 920, that had identical N-terminal amino acid sequences. This sequence was different from but homologous to the PLA2-I and PLA2-II sequences. Taken together, the results suggest that at least three different low-molecular-weight PLA2s are expressed in green rice shoots. Southern blot analysis suggested that multiple copies of such genes are likely to occur in the rice and in other plant genomes.

Comparison of 0.25 mg and 0.1 mg intrathecal morphine for analgesia after Cesarean section

PURPOSE

To test the hypothesis that 0.1 mg intrathecal morphine plus NSAIDs provides satisfactory analgesia post-Cesarean section with fewer side effects than 0.25 mg intrathecal morphine.

METHODS

Sixty women, scheduled for elective Cesarean section under spinal anesthesia, were randomized to receive either 0.1 mg or 0.25 mg intrathecal morphine combined with hyperbaric bupivacaine 0.75% and 20 microg fentanyl. All patients received a 100 mg indomethacin suppository at the end of surgery and 500 mg naproxen p.o. b.i.d. was started the evening of surgery and continued until discharge. A blinded researcher recorded the pain, pruritus, and nausea scores, the time to first request for additional analgesics, a visual analogue scale (VAS) satisfaction score, and the use of additional opioids, antipruritics, and/or antiemetics.

RESULTS

Of the 60 patients enrolled, two were not included in the data analysis because of protocol violations leaving 30 patients in the 0.1 mg group and 28 in the 0.25 mg group. There were no differences in the VAS pain scores or the number of women requesting an opioid other than codeine between the two groups. The VAS pruritus scores in the 0.1 mg group were lower throughout the 24 hr (P < 0.001). Fewer women in the 0.1 mg group (4/30 vs 12/28) requested nalbuphine to treat itching (P = 0.018). Nausea scores were lower in the 0.1 mg group (P < 0.001).

CONCLUSION

The use of 0.1 mg intrathecal morphine plus NSAIDs provides analgesia of similar quality to 0.25 mg but with fewer undesirable side effects following Cesarean section.

Geochemical consequences of increased atmospheric carbon dioxide on coral reefs

A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Medicare choices

There are new choices for Medicare beneficiaries, and individuals may be confused about what is available to them. Home care providers who understand these choices can be valuable resources to clients as well as to colleagues.