Development and Pollination Regulated Accumulation and Glycosylation of a Stylar Transmitting Tissue-Specific Proline-Rich Protein.

The extracellular matrix of stylar transmitting tissues of many angiosperms is enriched in secretory materials that are believed to be important for interactions with pollen tubes. We have previously characterized two related cDNAs (TTS-1 and TTS-2) for stylar transmitting tissue-specific proline-rich proteins (TTS proteins) from Nicotiana tabacum. We show here that TTS proteins are highly glycosylated proteins with apparent molecular masses ranging between 50 and 100 kD. Results from chemical and enzymatic deglycosylation suggest that TTS proteins have N-linked glycosyl groups, and the extensive glycosylation most probably has resulted from modifications at the proline residues. TTS proteins are localized to the intercellular regions between neighboring transmitting tissue cells, the space in which pollen tubes elongate as they migrate from the stigma toward the ovary. TTS mRNA and protein levels are regulated during pistil development and by pollination. The levels of TTS mRNAs and proteins increase with flower development and reach the maximal levels as flowers approach anthesis. These maximal levels are maintained in the styles for at least 3 to 4 days after pollination, during which time pollen tubes elongate and reach the ovary. Spatially, TTS mRNAs and proteins accumulate first in the stigmatic end of young styles, and their levels progressively increase toward the basal end as pistils mature. Pollination stimulates the levels of TTS mRNAs and proteins in hand-pollinated young styles, which normally accumulate relatively low levels of these TTS gene products. Pollination also qualitatively affects TTS mRNAs and proteins. In pollinated styles, TTS mRNAs are shorter than those in unpollinated styles and underglycosylated TTS protein species begin to accumulate. The elaborate regulatory mechanisms governing TTS mRNAs and proteins during development and by pollination strongly suggest that these proteins may play a functional role in the process of pollination.

Deep local hyperthermia for cancer therapy: external electromagnetic and ultrasound techniques.

External heating techniques for delivery of localized hyperthermia in patients are reviewed. This paper covers microwaves, radiofrequency, and ultrasound methods. Fundamental principles governing tissue absorption, guidelines for applicator selection and design, and restrictions of each heating approach are discussed. Innovative techniques utilizing multiple applicators to achieve better heating uniformity are also presented. The advantages and disadvantages of electromagnetic versus ultrasound heating techniques are compared as a conclusion to this review.

Maintenance of Chloroplast Components during Chromoplast Differentiation in the Tomato Mutant Green Flesh.

During ripening of tomato (Lycopersicon esculentum) fruit, chloroplasts develop into chromoplasts. The chloroplast-chromoplast transition is marked by the accumulation of carotenoids and the disappearance of chlorophyll, the degradation of the highly structured thylakoid membrane system, and a reduction in the levels of proteins and mRNAs associated with photosynthesis. In the tomato mutant green flesh (gf), detectable amounts of chlorophyll remain in the ripe, mutant fruit, giving rise to a rusty red fruit color and suggesting that at least chlorophyll degradation is defective in the mutant. We show here that the ultrastructure of the plastids in the ripe gf fruit maintained significant amouonts of the chloroplast thylakoid grana along with structures characteristic of tomato chromoplasts. The maintenance of chloroplast structure in the gf ripe fruit was paralleled on the molecular level by the retention of plastid photosynthetic components that normally decline significantly in ripening tomato fruits. These included the light-harvesting chlorophyll a/b-binding proteins of photosystem II, the second electron accepting plastoquinone of photosystem II binding protein, the large and small subunits of ribulose bisphosphate carboxylase/oxygenase, the 33-kD oxygen evolution protein, and cytochrome b559. Similarly, photosynthetic transcripts, cab, psbA, rbcL, rbcS, and psbE mRNAs, also accumulated to higher levels in ripening gf fruit than wild type. It is interesting that the levels of some of these transcripts, especially cab mRNA, were noticeably higher in the mature gf green fruit than in the corresponding wild-type fruit. This suggests that the onset of the effect from the gf mutation might be earlier than fruit ripening. We also observed that when chloroplast formation was blocked during the development and ripening of gf fruit, these mutant fruits were bright red and their chromoplasts were indistinguishable from those found in wild-type ripe fruits grown and ripened either in the dark or in the light. These results suggest that the lesion in gf may alleviate conditions associated with chloroplast deterioration during the chloroplast-chromoplast transition in tomato ripening but has no direct effect on chromoplast differentiation per se. The ultrastructure of gf provides unequivocal evidence that, in ripening tomato, chromoplasts indeed differentiate from preexisting chloroplasts; on the other hand, chromoplast differentiation in the dark-matured and -ripened tomato fruits indicates that chromoplast development can be a process entirely independent of the chloroplasts.

Systematic review: treatment of chronic hepatitis B virus infection by pegylated interferon.

BACKGROUND: Pegylated interferon-alpha has been shown to be more efficacious than conventional interferon in treating chronic hepatitis C. The use of peginterferon in chronic hepatitis B virus infection with positive hepatitis B e antigen has also been tested in a number of trials since 2003. AIM: To systematically summarize and compare the results of these studies. METHODS: Four studies were identified from PubMed, Medline and reference lists. Data from the trials were extracted and analysed. Where appropriate, combined odds ratio of different trials was calculated. Safety data including serious adverse events and emergence of drug-resistant mutants were recorded. RESULTS: Three of the four trials contained predominantly Asian patients. Peginterferon is found to be superior to lamivudine monotherapy and induced sustained biochemical and virological responses in about one-thirds of patients after 12 months of therapy. Coadministration of lamivudine did not result in improvement in viral suppression. Peginterferon appears to reduce the emergence of YMDD mutation in the combination treatment groups. It was well tolerated with serious adverse events reported in <10% of patients in most trials. CONCLUSIONS: Peginterferon-alpha treatment of at least 6 months should be considered as one of the first-line therapeutic options for hepatitis B virus infection.

Effects of a sonographic technique for determining chest wall thickness in treatment planning for breast carcinoma.

This study investigated the use of a sonographic technique of determining chest wall thickness and the impact of dosimetric correction for lung inhomogeneity on treatment planning for breast irradiation after lumpectomy or partial mastectomy. The thickness of the chest wall in three planes of the radiation field was obtained using a B-mode ultrasound scanner and the location of the pleura-lung interface was marked on the contour of the chest wall in each plane. Treatment plans for 88 patients were developed with and without correction for the lung tissue included in the radiation volume. All patients were irradiated with an opposing pair of tangential fields to the breast with a 6 MV X ray beam using an isocentric set-up. Within the treatment volume, dose variation of +/- 5% of the prescribed tumor dose was aimed for in the treatment planning. With correction for lung tissue, the proportion of treatments given with a wedge filter was found to be on the average 20% less than it would be without lung correction. The described sonographic technique is simple to perform and reproducible. It improves the accuracy of dosimetry in treatment planning for breast carcinoma.

Radiotherapy for primary carcinoma of the trachea.

Between 1940 and 1985, 24 cases of primary carcinoma of the trachea were registered at the London Regional Cancer Centre. The most common presenting symptoms were hoarseness, haemoptysis and cough. Twenty patients had epidermoid carcinoma and four had adenoid cystic carcinoma. Because of different clinical behaviours, the two histologies were separately analyzed. Of the 20 patients with epidermoid carcinoma, 19 received radiotherapy as primary treatment and one patient did not receive radiotherapy because of advanced disease. Radiation doses ranged from 4000 to 6000 cGy and most patients had megavoltage irradiation. Treatment result was disappointing. Only one patient remained disease-free at 15-month follow-up and all other patients had persistent or recurrent tracheal tumour. Median survival for all 20 patients was 5 months (range 1 to 19 months). Of the four patients with adenoid cystic carcinoma, two had primary surgery and postoperative radiotherapy and two had primary radiotherapy. Two patients died of disease, at 5 months and 8 years from diagnosis. Two surviving patients had 15-month follow-up: one had persistent disease and the other was free from recurrence. In this study, radiotherapy within the range of doses given was found to be an ineffective primary treatment for tracheal carcinoma.

Haematopoietic stem cell transplantation for thalassaemia major in Hong Kong: prognostic factors and outcome.

From August 1992 to August 1999, 44 patients received allogeneic haematopoietic stem cell transplantation in a single institution. The donors were HLA-identical siblings except for one who was a phenotypically matched father. Thirty-eight patients received bone marrow stem cells and the others received peripheral blood stem cells or umbilical cord blood (UCB). The mean age at transplant was 10.7+/-5.1 years, ranging from 1.8 to 21 years. Patients received busulphan (16 mg/kg) and cyclophosphamide (150 to 200 mg/kg) as conditioning, and antithymocyte globulin was given to 42 patients to prevent graft rejection. All had engraftment except a patient who received a UCB transplant. Four patients died from early treatment-related mortality, and one died from interstitial pneumonitis 3 months after transplant. Two patients developed secondary graft rejection and both received a second transplant. Thirty-eight patients survived and all except one were transfusion independent. The 5-year overall and event-free survival rates were 86% and 82%, respectively. By multivariate stepwise Cox proportional hazard analyses, severe veno-occlusive disease (VOD) of liver and Pesaro class 3 features were the significant factors associated with survival. Patients aged more than 11 years were more inclined to develop VOD. In conclusion, haematopoietic stem cell transplantation should be performed early if an HLA identical sibling is available.

Vitamin K-dependent carboxylase: partial purification of the enzyme by antibody affinity techniques.

The vitamin K-dependent carboxylase activity of bovine liver microsomes has been purified 500-fold by adsorption to an antiprothrombin column and elution with a dodeca peptide which competes with a prothrombin precursor enzyme recognition site. The purified enzyme is devoid of bound precursors, and has the same ratio of vitamin K epoxidase activity to carboxylase activity as the crude microsomal preparation.

Correction of microwave-induced thermistor sensor errors.

Accurate and reliable thermometry is essential in the development of microwave-induced hyperthermal cancer therapy. While temperature measurements in strong electromagnetic fields usually require special sensors, this does not hold true for interstitial radiator/sensor systems. Miniature thermistors (with metallic leads) bonded to invasive microwave applicators exhibit a sensor error linearly related to the radiator's transmitted power. This relationship permits thermistor sensor error correction and temperature measurements to within +/- 0.1 degrees C or better. The instrumental methods and empirical validation are presented.

Tuberculoma of the liver presenting as a hyperechoic mass on ultrasound.

An unusual case of hepatic macronodular tuberculoma is presented. As demonstrated by CT, the tuberculoma replaced the entire lateral segment of the left lobe of liver and resembled an infiltrative tumour. On ultrasound, the tuberculoma presented as a hyperechoic lesion, in contrast to a round hypoechoic mass which is usually seen in this condition. Hepatic macronodular tuberculomas are not uncommonly misdiagnosed as primary or secondary liver tumours by imaging studies, and the definite diagnosis is usually established by liver biopsy. The prognosis of hepatic macronodular tuberculoma is usually very good with effective treatment.

Metastatic adenocarcinoma of the uterine cervix to the thyroid gland.

Clinically diagnosed metastasis to the thyroid gland is rare. The authors present the first reported case of metastasis to the thyroid gland from a primary adenocarcinoma of the uterine cervix.

The effect of vertebral rotation of the lumbar spine on dual energy X-ray absorptiometry measurements: observational study.

OBJECTIVE: To estimate how axial rotation of lumbar vertebrae quantitatively affects bone mineral density, as measured by dual energy X-ray absorptiometry in the anteroposterior plane. DESIGN: Observational study. SETTING: University teaching hospital, Hong Kong. PATIENTS: Cadaver lumbar vertebrae (L2 to L4) were removed from four adults. MAIN OUTCOME MEASURES: Using dual energy X-ray absorptiometry, the bone mineral content, bone area, and bone mineral density were measured in the neutral position and with vertebral axial rotation in increments of 7.5 degrees, up to a maximum of 45 degrees. RESULTS: Correlation analysis showed a significant positive correlation between the degree of rotation and measured bone area, a significant negative correlation between degree of rotation and bone mineral density measurements, but no significant correlation between degree of rotation and measured bone mineral content. The measured bone area increased approximately 24% and the bone mineral density decreased approximately 19% when the vertebrae were rotated by 45 degrees. CONCLUSIONS: These results suggest that for patients with rotational deformity of the spine, such as scoliosis, measurements of lumbar spine bone mineral content by dual energy X-ray absorptiometry is not affected, while bone mineral density measurements are not reliable.

Longer term follow up of aerobic capacity in children affected by severe acute respiratory syndrome (SARS).

BACKGROUND: A study was undertaken to investigate the aerobic capacity and pulmonary function of children 6 and 15 months after the diagnosis of severe acute respiratory syndrome (SARS). METHODS: Thirty four patients of mean age 14.7 years completed both pulmonary function and maximal aerobic capacity tests at 6 months. All had normal clinical examination and were asymptomatic. Their exercise responses were compared with a group of healthy controls. Complete data were collected on 27 of the original 34 cases at 15 months. RESULTS: Compared with normal controls, the patient group had significantly lower absolute and mass related peak oxygen consumption (peak V o(2) (p<0.01)), higher ventilatory equivalent for oxygen (p<0.01), lower oxygen pulse (p<0.01), and a lower oxygen uptake efficiency slope (p<0.01) at 6 months. This impairment was unexpected and out of proportion with the degree of lung function abnormality. Residual high resolution computed tomography of thorax (HRCT) abnormalities were present in 14 patients. Those with abnormal HRCT findings had significantly lower mass related peak V o(2) than subjects with normal radiology (p<0.01). Absolute and mass related peak V o(2) in the patient group remained impaired at 15 months despite normalisation of lung function in all patients. CONCLUSIONS: The mechanism for the reduced aerobic capacity in children following SARS is not fully understood, but it is probably a consequence of impaired perfusion to the lungs at peak exercise and deconditioning.

Salvage radiotherapy for carcinoma of the ovary following chemotherapy.

Following single-agent or combination chemotherapy, 9 patients with epithelial carcinoma of the ovary had elective second-look laparotomy. Macroscopic intraperitoneal disease was resected in 4 patients. Therefore, after the laparotomy, all 9 patients had only biopsy-proven, microscopic residual disease, and they received whole abdominopelvic irradiation. Hematological tolerance was satisfactory, with only 2 patients developing asymptomatic thrombocytopenia. Mild gastrointestinal reactions, while frequent during radiotherapy, did not interrupt treatment in any patient. After follow-up from 12 to 34 months (median 16 months) [corrected], 2 patients died of cancer, 2 were alive with cancer, 3 were alive without clinical recurrence, and 2 were alive without biopsy-proven recurrence. Bowel complication occurred in 4 patients: 2 developed intestinal obstruction due to recurrent tumor, 1 developed subacute bowel obstruction which spontaneously resolved, and 1 patient required bowel resection because of a radiation complication. This study indicated that after single- or multiple-drug chemotherapy, most patients could complete the course of whole abdominopelvic irradiation. Gastrointestinal complications could be secondary to radiation damage or to recurrent tumor. While whole abdominopelvic irradiation was not an effective second-line treatment, some long-term survivors could still be expected.

Prognostic significance of negative hysterectomy specimen following intracavitary irradiation in stage I endometrial carcinoma.

Clinical stage I endometrial carcinoma in 353 women was treated by pre-operative intracavitary irradiation with radium and total abdominal hysterectomy with bilateral salpingo-oophorectomy. No residual tumour was found in 36 per cent of uterine specimens obtained from hysterectomies performed within two weeks compared to 59 per cent of those removed later than eight weeks after the intracavitary irradiation. A negative hysterectomy specimen was a favourable prognostic index. Patients with no residual tumour in the hysterectomy specimens had a significantly lower five-years relapse rate (3.8 per cent) than those with residual tumour (19.2 per cent).

Microwave and radiofrequency techniques for clinical hyperthermia.

Biological and practical constraints on the use of clinical hyperthermia for the management of cancer are discussed. Commonly used electromagnetic techniques for producing clinical hyperthermia are reviewed and compared. Innovative engineering designs leading to the realization of an integrated, safe and reliable clinical hyperthermia system are also presented.

Molecular analysis of an aurea photosynthetic mutant (Su/Su) in tobacco: LHCP depletion leads to pleiotropic mutant phenotypes.

Su is a nuclear encoded, semi-dominant aurea mutation in Nicotiana tabacum L. The homozygous plants (Su/Su) are pale yellow and non-photosynthetic while the heterozygous (Su/+) are photosynthetically competent and have a yellow-green phenotype which is distinct from that of green wild-type plants (+/+). We have examined the RNA and protein levels for a number of nuclear and plastid encoded chloroplast proteins under high and low light plant growth conditions. Under high light conditions, the light-harvesting chlorophyll a/b binding proteins (LHCP) were undetectable in the homozygous Su/Su plants, and the large subunit (LSu) and the small subunit (SSu) of ribulose bisphosphate carboxylase (Rubisco) and cytochrome b559 were severely deficient. However, only the nuclear encoded cab and plastid encoded psbE mRNA (encoding LHCP and cytochrome b559 respectively) were reduced significantly. In heterozygous Su/+ plants, the level of LHCP was reduced to 25% of that in wild-type plants while cab and psbE mRNA, LSu, SSu and cytochrome b559 remained at normal levels, suggesting that LCHP is more immediately affected by the Su mutant gene product than the rest of the photosynthetic proteins and mRNA examined. Under low light conditions, the levels of cab and psbE mRNA, LSu, SSu and cytochrome b559 in homozygous Su/Su plants were equivalent to those in wild-type plants except LHCP which remained undetectable. Similarly, the LHCP level in low light grown Su/+ plants still remained at 25% of wild-type level. These results indicate that the decrease in LHCP is independent of light conditions and has not resulted from photooxidation, whereas the depletion of other proteins and mRNA examined under high light growth conditions is a consequence of photooxidative damage to Su/Su plastids. Furthermore, transgenic Su/Su and Su/+ plants with a cauliflower mosaic virus 35S (CaMV 35S)-cab construct constitutively maintained high levels of cab mRNA but displayed the same pattern of diminished LHCP accumulation as their non-transformed counterparts when grown under both high and low light conditions. These results indicate that the Su mutation primarily causes depletion of LHCP. The depletion of LHCP leads to photooxidative damage which results in decreased cab mRNA levels and other pleiotropic lesions in Su/Su plants.