Endometrial stromal sarcoma mimicking submucosal myoma protruding to the vagina: MRI findings

A 46-year-old woman complained of persistent abnormal vaginal bleeding over ten days. Her intrauterine device had been removed two years before. Soon after, she suffered from menorrhagia and metrorrhagia. An incidental finding of severe anemia was also noted. In this admission, our initial T2-weighted magnetic resonance imaging (MRI) revealed a well-demarcated mass predominantly in the uterine cavity. The mass was depicted by an isointense signal relative to the myometrium on T1-weighted images, high signal intensity on T2-weighted images, and slightly heterogeneous enhancement on post-contrast images. The patient refused surgery. After two years, follow-up MRI showed a pedunculated mass protruding into the upper third of the vagina with a stalk connecting to the posterior wall of the uterine cavity, simulating submucosal myoma. Histological diagnosis was compatible with low-grade endometrial stromal sarcoma.

Radical hysterectomy: past, present, and future

After an analysis of 3,441 radical hysterectomies performed in our department, we found, after modification of the operative technique in 1983, the more lateral the excision the less the recurrence rate. The recurrence rate for Stage 1b-2a and Stage 2b patients comparing the years before 1983 to the years after decreased to 12.4% from 15.7% (158/1,006 vs 268/2,163; p = 0.009) in Stage 1b-2a and 24.6% from 55.8% (38/68 vs 47/191; p = 0.0007) in Stage 2b, respectively. With the modern trend of aspiring for an easier lifestyle, most physicians practice earlier. Therefore only very few physicians study radical hysterectomy. As the skill of surgery needs a longer period of education and training, it may only interest physicians who work with medical professionals as part of a team at a medical center. In the future, we should provide gynecological residents not only with a training program using the classic textbooks, but also with different points of view on changes and developments in radical hysterectomy. We hope to promote an attitude of offering patients access to different choices and opportunities of therapy. Radical hysterectomy is in fact a treatment option for patients with bulky cervical lesions and Stage 2b in particular.

Cold perfluorochemical-induced hypothermia protects lung integrity in normal rabbits

To test the hypothesis that intrapulmonary perfluorochemical (PFC) liquid may induce hypothermia, and to compare the effects of internal (IC), external (EC), and combined cooling techniques (EC + IC), 14 juvenile rabbits were randomized to EC by a cold blanket (4 degrees C, n = 5), IC by intrapulmonary cold PFC liquid lavage (4 degrees C, n = 5), or combined IC with PFC and EC (n = 4). Arterial blood gas, blood pressure, and lung mechanics were monitored, and lung histology was examined by light microscopy. The results showed that cooling rates and the time needed to be cooled down to 30 degrees C were significantly faster in EC and EC + IC than IC (p < 0.05). Blood gas analysis and cardiopulmonary function were within the normal range in all groups. Histological assessment revealed varied atelectasis in all lung regions in EC, whereas PFC-filled lungs (IC and EC + IC) demonstrated more homogenous expansion and no evidence of atelectasis. The results indicate that intrapulmonary PFC may be an effective technique to induce and/or augment hypothermia while supporting gas exchange, lung volume and pulmonary architecture.

Sequential changes to clinical parameters and adhesion molecules following intravenous pulse cyclophosphamide and methylprednisolone treatment of refractory juvenile idiopathic arthritis

It is believed that the systemic subtype and the positive rheumatoid factor, polyarticular subtype of juvenile idiopathic arthritis (JIA) show the least favorable outcomes for therapy; patients with systemic JIA are often resistant to recommended therapeutic modalities. We report the sequential changes to clinical and laboratory findings from pulse therapy with monthly intravenous cyclophosphamide (0.5 g/m2 body surface area) administration combined with methylprednisolone (30 mg/kg; 1 gm maximum) for 6 months, following which the medication interval was elongated to 3 months for a total of from 7 to 12 courses. Among 4 children suffering from refractory systemic JIA, 3 demonstrated clinical improvement, 2 of whom achieved clinical remission. Furthermore, we also adminstered this therapy to a girl suffering from refractory polyarticular JIA, following which she revealed clinical remission subsequent to 9 courses of such therapy. From our experience, we suggest that patients afflicted with JIA that is unresponsive to traditional medication may experience benefit from this type of pulse therapy.

Yeast TOR signaling: a mechanism for metabolic regulation

Understanding how cell growth is regulated in response to environmental signals remains a challenging biological problem. Recent studies indicate the TOR (target of rapamycin) kinase acts within an intracellular regulatory network used by eukaryotic cells to regulate their growth according to nutrient availability. This network affects all aspects of gene expression, including transcription, translation, and protein stability, making TOR an excellent candidate as a global regulator of cellular activity. Here we review our recent studies of two specific transcriptional outputs controlled by TOR in the budding yeast, S. cerevisiae: (1) positive regulation of genes involved in ribosome biogenesis, and (2) negative regulation of genes required for de novo biosynthesis of glutamate and glutamine. These studies have raised the important issue as to how diverse nutritional cues can pass through a common signaling pathway and yet ultimately generate distinct transcriptional responses.

Modelling of signalling via G-protein coupled receptors: pathway-dependent agonist potency and efficacy

A mathematical model is constructed to study promiscuous coupling of receptors to G-proteins and to simulate events leading to the activation of multiple effector pathways within a cell. The model is directed at a better understanding of the factors that determine the efficacy and potency of a drug. Assuming that the receptors can exist in multiple conformational states, and allowing for agonist specific conformation, a system of ordinary differential equations is constructed and subsequently pathway-dependent agonist efficacy and potency order is predicted. A simple case of the compartmentalization of receptors and G-proteins is also given, using the current model to illustrate the effects of spatial heterogeneity on the predicted response.

Monthly Recurrent Herpes Simplex Virus Blepharitis in a Boy for More Than 10 Years

Ocular herpes simplex virus (HSV) infection is generally accepted to be a unilateral disease and simultaneous bilateral recurrent ocular HSV disease is uncommon. Recurrent ocular herpes was generally thought to be characterized by corneal involvement. We here report an 11-year-old boy with monthly bilateral recurrent HSV type 1 blepharitis for more than 10 years. He had a general normal immunological examination. Only supportive or topical acyclovir ointment treatment proved adequate for controlling the monthly recurrent disease without corneal involvement or other sequelae to date. The case highlights the unusual presentation, general normal immune function, clinical course and treatment opinion for recurrent HSV blepharitis.

Use of a new fluorescence immunoassay to detect anti-dsDNA antibodies is more correlated with disease activity and complement than the ELISA method in SLE patients

To determine whether the serum levels of anti-double strand DNA (anti-dsDNA) autoantibodies detected using a newly developed fluorescence immunoassay (FIA) in patients with systemic lupus erythematosus (SLE) correlated more with clinical parameters, such as SLE disease activity index (SLEDAI), complement and the occurrence of nephritis when compared with traditional enzyme-linked immunosorbent assay (ELISA), we prospectively collected 124 serum samples from 31 patients who had juvenile-onset SLE and were regularly monitored every 2 months at our outpatient clinic. At every visit, clinical manifestations and laboratory parameters were assessed and the SLEDAI was determined. Correlation analyses between the two different measurements of anti-dsDNA antibodies and SLEDAI, serum complement levels and the occurrence of nephritis were performed. The results showed that anti-dsDNA autoantibodies detected using both ELISA and FIA significantly correlated with SLEDAI, and significantly and inversely correlated with the serum levels of C3 and C4. FIA had significantly higher correlation with SLEDAI and C4 than did ELISA. The mean values of anti-dsDNA antibodies detected using FIA in patients with nephritis were significantly higher than in those without nephritis. In contrast, the values of anti-dsDNA antibodies detected using ELISA did not show significant differences between these two groups. We conclude that FIA had better correlation with SLEDAI, C4 and the occurrence of nephritis, and comparable correlations with C3 that were similar to the results found using ELISA. Thus, it is worthwhile developing the FIA method for clinical evaluation of disease activity in SLE patients.

Increasing relative prevalence of HSV-2 infection among men with genital ulcers from a mining community in South Africa

OBJECTIVES

To determine the aetiology of genital ulcer disease (GUD) and its association with HIV infection in the mining community of Carletonville, South Africa, from two cross sectional surveys of consecutive men presenting with genital lesions during October 1993 to January 1994 and July to November 1998.

METHODS

A multiplex polymerase chain reaction (M-PCR) assay combined with amplicon detection was used to identify DNA specific sequences of Treponema pallidum, herpes simplex virus (HSV), and Haemophilus ducreyi. A real time PCR assay was used to differentiate between HSV-1 and HSV-2.

RESULTS

M-PCR detected T pallidum, HSV, and H ducreyi in 10.3%, 17.2%, and 69.4% of 232 GUD patients during 1993-4 and in 12.4%, 36.0%, and 50.5% of 186 GUD patients in 1998. The proportion of patients with more than one agent increased significantly from 7.3% (17/232) in 1993-4 to 16.7% (31/186) in 1998 (p <0.01). HSV-2 was detected in a higher proportion of ulcer specimens from HIV infected patients than in specimens from HIV uninfected patients during both time periods (1993-4: 26.2% v 6.7%, p <0.001; 1998: 42.1% v 29.6%, p >0.09).

CONCLUSIONS

Based on two cross sectional surveys, 4 years apart, chancroid remained the leading cause of GUD in men who presented at the STD clinic with genital ulcers in the mining community of Carletonville, South Africa. The relative prevalence of primary syphilis has remained low. However, HSV-2 has emerged as a more significant cause of GUD and the proportion of GUD patients infected with more than one agent also increased significantly. HSV-2 DNA was detected in a significantly higher proportion of ulcer specimens from HIV positive patients than from HIV negative patients. No association was found between HIV infection status and the relative prevalence of chancroid or syphilis.

Implementation of a short-tip tapping-mode tuning fork near-field scanning optical microscope

We present the implementation of a short-tip tapping-mode tuning fork near-field scanning optical microscope. Tapping frequency dependences of the piezoelectric signal amplitudes for a bare tuning fork fixed on the ceramic plate, a short-tip tapping-mode tuning fork scheme and an ordinary tapping-mode tuning fork configuration with an 80-cm optical fibre attached are demonstrated and compared. Our experimental results show that this new short-tip tapping-mode tuning fork scheme provides a stable and high Q factor at the tapping frequency of the tuning fork and will be very helpful when long optical fibre probes have to be used in an experiment. Both collection and excitation modes of short-tip tapping-mode tuning fork near-field scanning optical microscope are applied to study the near-field optical properties of a single-mode telecommunication optical fibre and a green InGaN/GaN multiquantum well light-emitting diode.

Our experience with eclampsia in Singapore

AIM

To assess the incidence, epidemiological factors, preceding symptoms and signs, management regimens and obstetric outcomes of eclampsia in a tertiary care hospital in Singapore.

METHOD

A retrospective study of all obstetric patients who suffered one or more eclamptic seizures in our hospital between January 1994 and December 1999.

RESULT

There were 62 cases of eclampsia among 92,305 deliveries (6.7 per 10,000 deliveries). The incidence was highest among Indians. Those aged between 25 and 34 had the lowest incidence, while women younger than 25 or older than 34 had a significantly higher incidence. Forty (64.5%) patients had symptom or sign of impending eclampsia of which headache was the most common. Most of the patients (81.6%) who received antenatal care with us suffered their first eclamptic seizure in hospital, compared to 50% of the unbooked patients. There was one maternal death (mortality rate 1.6%), and 15 (24.2%) women had significant morbidity. There were 61 singleton pregnancies and one twin pregnancy. There were six intrauterine deaths and 57 livebirths. The perinatal mortality rate was 95.2 per 1,000 births.

CONCLUSION

Eclampsia is still a major cause of maternal and foetal mortality and morbidity in Singapore. Race and age appear to be risk factors for eclampsia with Indian women and those at the extremes of reproductive age at greater risk. Antenatal care is important in reducing perinatal mortality and possibly maternal complications.

Clinical comparison of high-dose interferon-alpha2b with or without ribavirin for treatment of interferon-relapsed chronic hepatitis C

BACKGROUND

Interferon a with ribavirin combination therapy is effective but still unsatisfactory in the treatment of patients with interferon-relapsed chronic hepatitis C.

AIMS

To compare, in a randomized, double blind, placebo-controlled study, high-dose interferon-alpha2b with or without ribavirin in the treatment for interferon-relapsers.

PATIENTS

A total of 52 patients with interferon-relapsed chronic hepatitis C were randomly assigned to receive 24-week treatment with interferon-alpha2b (6 MU three times per week) combined with either ribavirin (1,000 to 1,200 mg per day) or a matched placebo and then followed for an additional 24 weeks.

METHODS

Hepatitis C virus RNA was detected by reverse-transcription polymerase chain reaction. For determining viral concentration, the commercial bDNA Quantiplex hepatitis C virus-RNA 2.0 assay was used. Genotyping was performed by reverse hybridization assay

RESULTS

At the end of treatment, no detectable hepatitis C virus RNA levels were observed in 92% (24/26) of patients on interferon alpha2b/ribavirin and 81% (21/26) of patients on interferon alpha2b/placebo. At the end of the follow-up, a higher sustained virological response rate was seen in patients treated with interferon alpha2b/ribavirin than those treated with interferon alpha2b/placebo (69% vs 23%, p < 0.001). Patients with either initially high levels of viral concentration or with genotype 1 responded poorly. Patients who received interferon-alpha2b/ribavirin treatment and in whom no hepatitis C virus RNA was detected at 4th week after treatment had 90% chance to achieve sustained virological response.

CONCLUSIONS

High-dose interferon-alpha2b plus ribavirin treatment is highly effective in interferon-relapsed patients.

A preliminary study of chromium distribution in chromium-rich brewer's yeast cell by NAA

The purpose of this study was to assess the chromium (Cr) distribution in chromium-rich brewer's yeast cell. The chromium concentrations in the cell wall and protoplast fractions of the chromium-rich yeast were determined by neutron activation analysis (NAA). Moreover, the combined state of chromium and amino acid content in the Cr-rich brewer's yeasts was analyzed and measured. The experimental results indicate that the introduction of water-soluble chromium(III) salt as a component of the culture medium for yeasts results in a substantial amount of chromium absorbed through the cell wall by the yeast, among which 80.9% are accumulated in the protoplast. It implies that, under optimal conditions, yeasts are capable of accumulating large amounts of chromium and incorporating chromium into organic compounds.

Expression of apoptosis-regulating proteins p53, Bcl-2, and Bax in primary resected esophageal squamous cell carcinoma

Apoptosis plays a key role in the pathogenesis, aggressiveness, and therapy responsiveness of cancer. Proteins of the Bcl-2 family as well as p53 are important regulators of apoptosis. The present study retrospectively examines the expression of apoptosis-regulating proteins in primary resected esophageal squamous cell carcinoma (ESCC) and the correlation between the outcome of patients' treatment and the expression of the proteins. We used antibodies specific for the human p53, Bcl-2 and Bax proteins to examine the expression of these apoptosis-regulating proteins in 40 archival specimens of patients with primary resected esophageal squamous cell carcinoma. The overall expression of p53, Bcl-2, and Bax was 73%, 18%, and 100%, respectively. No significant correlations were found between the expression of p53, Bcl-2, and Bax. The expression of Bcl-2 had a negative influence on survival in this population of primary resected ESCC patients (p=0.03). But no differences in survival were observed in relation to the expression of p53 or Bax. In conclusion, Bcl-2 expression may provide additional and prognostic information for the clinical course of the disease and therefore to be developed as a prognostic indicator for primary resected esophageal squamous cell carcinoma.

Biological basket weaving: formation and function of clathrin-coated vesicles

There has recently been considerable progress in understanding the regulation of clathrin-coated vesicle (CCV) formation and function. These advances are due to the determination of the structure of a number of CCV coat components at molecular resolution and the identification of novel regulatory proteins that control CCV formation in the cell. In addition, pathways of (a) phosphorylation, (b) receptor signaling, and (c) lipid modification that influence CCV formation, as well as the interaction between the cytoskeleton and CCV transport pathways are becoming better defined. It is evident that although clathrin coat assembly drives CCV formation, this fundamental reaction is modified by different regulatory proteins, depending on where CCVs are forming in the cell. This regulatory difference likely reflects the distinct biological roles of CCVs at the plasma membrane and trans-Golgi network, as well as the distinct properties of these membranes themselves. Tissue-specific functions of CCVs require even more-specialized regulation and defects in these pathways can now be correlated with human diseases.

Molecular typing of Treponema pallidum in South Africa: cross-sectional studies

We evaluated a molecular subtyping system for Treponema pallidum for its ability to differentiate between strains obtained from male patients with primary syphilis in South Africa. Of 201 T. pallidum-positive specimens, 161 were typeable, revealing 35 subtypes. The unique subtypes identified in Durban, Cape Town, and Carletonville and the total number of subtypes suggested that the strain population was very diverse and varied geographically.

[Changes of serum soluble tumor necrosis factor receptor I in patients with rheumatic fever]

OBJECTIVE

To study the changes and the effects of soluble tumor necrosis factor receptor I (sT-NFR I) in patients with rheumatic fever, and to find out the laboratorial marker of clinic activity in patients with rheumatic fever.

METHODS

The serum concentrations of sTNFR I in 16 patients with ARF, 16 patients with chronic inactive rheumatic heart disease (CRHD) and 15 healthy controls were measured by methods of ELISA and the relationship between sTNFR I and ESR or CRP were studied.

RESULTS

The sTNFR I serum concentrations in patients with ARF (3.92 +/- 1.28) ng.ml-1 were significantly higher than those with CRHD (1.43 +/- 0.66) ng.ml-1 and healthy controls (1.06 +/- 0.42) ng.ml-1 (all P < 0.01). The serum concentrations of sTNFR I in patients with CRHD were almost the same with those in healthy controls (P > 0.05); Their positive correlation was significantly observed between sTNFR I and CRP(P < 0.001), and wasn't observed between sTNFR I and ESR.

CONCLUSION

The Patients with ARF have high serum levels of sTNFR I. It may be used as the laboratorial marker in the clinic assessment of activity in patients with rheumatic fever.

Reduction of subretinal fluid after preoperative immobilization of the eyes with rhegmatogenous retinal detachment

BACKGROUND

Bullous retinal detachment may be difficult to handle with higher operative complications. Preoperative immobilization of the eyes might reduce subretinal fluid and facilitate surgical procedures. Factors influencing subretinal fluid absorption were analyzed.

METHODS

Twenty-eight eyes with primary rhegmatogenous retinal detachment with preoperative binocular patching and complete bed rest for at least 12 hours were enrolled. Ultrasonography was performed before and after immobilization to estimate the reduction in subretinal fluid.

RESULTS

The amount of reduction diverged in cases with an average of a 17.1% decrease in the maximal height of detachment. Retinal detachments in patients with smaller breaks and without vitreal traction or chronicity showed more significant reduction of subretinal fluid than did those patients with larger breaks and with vitreal traction or chronicity. On the other hand, break shape, height of retinal detachment, age, and gender had no obvious effect on subretinal fluid change.

CONCLUSIONS

Preoperative immobilization of the eyes reduces the subretinal fluid in selected cases, which can decrease operative complications. Break size, vitreal traction, and chronicity are important factors affecting the absorption of subretinal fluid.

AU binding proteins recruit the exosome to degrade ARE-containing mRNAs

Inherently unstable mammalian mRNAs contain AU-rich elements (AREs) within their 3' untranslated regions. Although found 15 years ago, the mechanism by which AREs dictate rapid mRNA decay is not clear. In yeast, 3'-to-5' mRNA degradation is mediated by the exosome, a multisubunit particle. We have purified and characterized the human exosome by mass spectrometry and found its composition to be similar to its yeast counterpart. Using a cell-free RNA decay system, we demonstrate that the mammalian exosome is required for rapid degradation of ARE-containing RNAs but not for poly(A) shortening. The mammalian exosome does not recognize ARE-containing RNAs on its own. ARE recognition requires certain ARE binding proteins that can interact with the exosome and recruit it to unstable RNAs, thereby promoting their rapid degradation.

Paralytic shellfish poisoning toxins accumulation in purple clam Hiatula rostrata and toxic effect on milkfish Chanos chanos larval fish

In an attempt to feed purple clams (Hiatula rostrata) with dinoglagellate Alexandrium minutum, the maximal accumulation toxicity of paralytic shellfish poisoning (PSP) toxins reached 40.6 MU/g on day 5 of feeding. Subsequently, the toxicity increased no further, although purple clams ingested more toxic algae. Furthermore, when milkfish (Chanos chanos) larvae were treated with toxic, nontoxic A. minutum or PSP toxin-containing extract in the water medium, it was found that the mortality of fish increased with the increasing concentrations of toxic algae. PSP toxin-containing extract did not show any toxic effect on milkfish larvae.

Hypodipsic hypernatremia and diabetes insipidus following anterior communicating artery aneurysm clipping: diagnostic and therapeutic challenges in the amnestic rehabilitation patient

Hypodipsic hypernatremia (HH) represents a pathological increase in serum sodium due to a lack of thirst and defect in hypothalamic osmoreceptors. While 15% of patients with HH have a vascular aetiology, few cases have been described. Moreover, the presence of such abnormalities in the amnestic patient can have particularly threatening implications, as HH tends to recur unless the patient complies with a regimen of water intake. This study reports the case of a 46-year-old male admitted for rehabilitation of functional deficits following subarachnoid haemorrhage (SAH), with clipping of an anterior communicating artery (ACoA) aneurysm. Clinical examination was remarkable for profound short-term memory loss and inability to retain new information. Blood chemistry on admission showed a serum sodium level of 160 mEq/L, increasing to 167 mEq/L the following day. The patient denied thirst, and showed no clinical signs of dehydration. Neuroendocrine evaluation revealed diabetes insipidus (DI) and HH. Treatment initially included DDAVP and intravenous hydration, later supplemented with chlorpropramide. Stabilization of serum sodium and osmolality did not ensue until the treatment regimen included hydrochlorothiazide and supervision of enforced fluid intake. Endocrine abnormalities may be encountered among patients with vascular lesions adjacent to the hypothalamus. Rehabilitation interventions include establishing a structured medication regimen with fluid administration in the amnestic patient with hypothalamic dysfunction.

Clathrin hub expression dissociates the actin-binding protein Hip1R from coated pits and disrupts their alignment with the actin cytoskeleton

The actin cytoskeleton has been implicated in the maintenance of discrete sites for clathrin-coated pit formation during receptor-mediated endocytosis in mammalian cells, and its function is intimately linked to the endocytic pathway in yeast. Here we demonstrate that staining for mammalian endocytic clathrin-coated pits using a monoclonal antibody against the AP2 adaptor complex revealed a linear pattern that correlates with the organization of the actin cytoskeleton. This vesicle organization was disrupted by treatment of cells with cytochalasin D, which disassembles actin, or with 2,3-butanedione monoxime, which prevents myosin association with actin. The linear AP2 staining pattern was also disrupted in HeLa cells that were induced to express the Hub fragment of the clathrin heavy chain, which acts as a dominant-negative inhibitor of receptor-mediated endocytosis by direct interference with clathrin function. Additionally, Hub expression caused the actin-binding protein Hip1R to dissociate from coated pits. These findings indicate that proper function of clathrin is required for coated pit alignment with the actin cytoskeleton and suggest that the clathrin-Hip1R interaction is involved in the cytoskeletal organization of coated pits.

Practical asymmetric synthesis of a selective endothelin A receptor (ETA) antagonist

[structure: see text]. A practical, chromotography-free asymmetric synthesis was developed for the large scale preparation of an endothelin receptor antagonist 2. This synthesis includes a new efficient process for the preparation of 6-bromo-2,3-dihydrobenzofuran, a stereoselective conjugate addition of an aryllithium followed by stereospecific addition of the Grignard reagent of the top aryl bromide, and an aminophosphate-mediated sterospecific intramolecular enolate alkylation, which led to the formation of the five-membered ring bearing three contiguous asymmetric centers.

Different risks of symptomatic brain necrosis in NPC patients treated with different altered fractionated radiotherapy techniques

PURPOSE

To report our observation of excessive temporal lobe necrosis in nasopharyngeal carcinoma (NPC) patients treated with 160 cGy b.i.d. radiotherapy technique. During the same period, patients treated with 120 cGy b.i.d. have not shown a similar tendency. Our experience may be useful for designing unconventional radiotherapy regimens for NPC patients.

METHODS AND MATERIALS

During the period from October 1991 to January 1998, 81 M0, previously untreated NPC patients completed altered fractionated radiotherapy. Seventy patients were treated with the hyperfractionated technique, and 11 were treated using the accelerated-hyperfractionated scheme. Hyperfractionated radiotherapy was delivered using 120 cGy b.i.d. separated by 6-h intervals throughout the course. A minimum tumor dose of 8000 cGy was the standard dose over an 8-week period. With the accelerated-hyperfractionated scheme, 160 cGy was given twice daily, also with an interval of 6 h. The minimum tumor dose ranged between 6840 and 7640 cGy, with 7 of the 11 patients receiving 7000 cGy. The arrangement of portals was the same for both regimens. The follow-up period for patients alive was from 32 to 102 months with a median of 61 months for the hyperfractionated patients. For the accelerated-hyperfractionated group, it ranged from 67 to 82 months with a median of 72 months. No patient was lost to follow-up.

RESULTS

At the time of analysis, 49 of the 70 patients in the hyperfractionated group were alive. In the accelerated group, 8 of the 11 patients were alive. The estimated radiation dose to the temporal lobe for the hyperfractionated group was 6000-7440 cGy with a median of 7080 cGy. For the accelerated-hyperfractionated group, the dose range was 4480-6700 cGy with a median of 6400 cGy. Of the 70 patients treated with hyperfractionated radiotherapy, none developed symptomatic brain necrosis, despite the higher total dose to the temporal lobe in general. In contrast, 3 of the 11 (27%) patients irradiated using the accelerated-hyperfractionated regimen suffered from temporal lobe necrosis at 16, 19, and 40 months after completion of radiotherapy.

CONCLUSION

An excessive incidence of temporal lobe necrosis was noted when an accelerated-hyperfractionated regimen with 160 cGy b.i.d. was used in NPC patients with a median brain dose of 6400 cGy. There has been no such event in patients treated using a hyperfractionated regimen with 120 cGy and a median brain dose of 7000 cGy. The real causes of this discrepancy are not known. However, a high sensitivity of the human brain to a change in fraction size may play a role.

Time course of cerebral infarction in the middle cerebral arterial territory: deep watershed versus territorial subtypes on diffusion-weighted MR images

PURPOSE

To examine possible differences between the evolution of cerebral watershed infarction (WI) and that of territorial thromboembolic infarction (TI) by using diffusion-weighted (DW) and T2-weighted magnetic resonance (MR) images and apparent diffusion coefficient (ADC) maps.

MATERIALS AND METHODS

Fourteen patients with TI and nine with WI underwent MR imaging from the acute to chronic infarction stages. ADC maps were derived from DW images. Lesion-to-normal tissue signal intensity ratios on ADC maps (rADC), echo-planar T2-weighted images, and DW images were calculated. Lesion volumes at acute or early subacute infarction stages were measured on DW images, and final lesion volumes were estimated on fluid-attenuated inversion-recovery images.

RESULTS

Analysis of variance revealed a significant difference in temporal evolution patterns of rADC between WI and TI (P <.001). rADC pseudonormalization following TI began about 10 days after symptom onset, but that following WI did not occur until about 1 month after symptom onset. The Pearson correlation coefficient between final and initial infarct volumes was 0.9899 for both infarction subtypes, indicating that the initial ischemic injury volume measured at the acute or early subacute stage predicted the final lesion volume fairly well.

CONCLUSION

The evolution time of ADC is faster for TI than for WI. This difference, which likely originates from the different pathophysiologic and hemodynamic features of the two infarction types, might account for the relatively large range of ADC values reported for the time course of ischemic strokes.

Extended allergen exposure in asthmatic monkeys induces neuroplasticity in nucleus tractus solitarius

BACKGROUND

Extended exposure to allergen exacerbates asthma symptoms, in part via complex interactions between inflammatory cells and mediators. One consequence of these interactions is the triggering of local and central nervous system (CNS) neuronal activity that might further exacerbate the asthma-like symptoms by causing bronchoconstriction, mucous secretion, increased microvascular leak, and cough. One CNS region that might be particularly important is the caudomedial nucleus tractus solitarius (NTS). NTS neurons not only integrate primary afferent inputs from lung sensory nerve fibers but also have direct exposure to inhaled allergens and allergen-induced blood-borne inflammatory mediators via a deficient blood-brain barrier. Given the capacity of CNS neurons to undergo plasticity, allergen-induced changes in NTS neuronal properties could contribute to the exaggerated respiratory responses to extended allergen exposure.

OBJECTIVE

In a recently developed rhesus monkey model of allergic asthma, we tested the hypothesis that extended exposure to allergen increases the intrinsic excitability of NTS neurons.

METHODS

Three adult monkeys were sensitized and then repeatedly exposed to aerosols of house dust mite allergen; 4 monkeys served as controls. Whole-cell current-clamp recordings were made to measure 3 indices of excitability: resting membrane potential, input resistance, and number of action potentials evoked by current injections.

RESULTS

Extended allergen exposure depolarized the resting membrane potential by 14% and increased the number of action potentials evoked by current injections (5-fold).

CONCLUSION

The finding that NTS neurons in a primate model of allergic asthma undergo intrinsic increases in excitability suggests that CNS mechanisms might contribute to the exaggerated symptoms in asthmatic individuals exposed to allergen.

Imaging findings of intradiaphragmatic bronchogenic cyst: a case report

Isolated intradiaphragmatic bronchogenic cysts are extremely rare. Here, we report a case of intradiaphragmatic bronchogenic cyst with calcifications in a 34-year-old man presenting with no clinical symptoms. Imaging studies of the chest, including chest roentgenogram and computerized tomography (CT), revealed a left posterior mediastinal mass that abutted onto the left diaphragmatic crus with multiple calcifications and showed no enhancement after contrast administration on CT. The patient underwent surgical resection of the mass. Intradiaphragmatic bronchogenic cyst with calcifications was diagnosed by pathology. The patient was discharged 10 days after the operation, and no complication was found 3 months later at follow-up.

Experiences in thoracoscopic sympathectomy for axillary hyperhidrosis and osmidrosis: focusing on the extent of sympathectomy

HYPOTHESIS

A more selective sympathectomy can improve the outcome of axillary hyperhidrosis and osmidrosis and minimize the potential sequelae.

DESIGN

Retrospective cohort.

SETTING

Tertiary care center.

PATIENTS

Between July 1, 1996, and May 30, 2000, 171 patients with axillary hyperhidrosis and osmidrosis were studied.

INTERVENTIONS

T3-4 sympathectomies were performed in 40 patients (group 1), T4 sympathectomies were performed in 56 patients (group 2), and T4-5 sympathectomies were performed in 75 patients (group 3).

MAIN OUTCOME MEASURES

The surgical outcomes were evaluated by direct patient interview in the outpatient clinic or by telephone or mail questionnaires. The results were categorized as excellent (significant or complete disappearance of symptoms), good (>/=50% improvement), or poor (<50% improvement).

RESULTS

There were no surgical mortalities in this study. Twenty-eight group 1 patients (70%), 16 group 2 patients (29%), and 22 group 3 patients (29%) developed compensatory perspiration (P<.001). Six group 1 patients (15%), 1 group 2 patient (2%), and 1 group 3 patient (1%) developed dry hands (P =.02). In the group 1 patients, the surgical outcomes were excellent in 21 (52%), good in 6 (15%), and poor in 13 (32%). In the group 2 patients, the surgical outcomes were excellent in 29 (52%), good in 10 (18%), and poor in 17 (30%). In the group 3 patients, the surgical outcomes were excellent in 53 (71%), good in 11 (15%), and poor in 11(15%) (P =.04). (Percentages may not sum to 100 because of rounding.)

CONCLUSION

T4-5 sympathectomies provide higher patient satisfaction rates in treating axillary hyperhidrosis and osmidrosis, with fewer sequelae.

Versatile role for hnRNP D isoforms in the differential regulation of cytoplasmic mRNA turnover

An important emerging theme is that heterogeneous nuclear ribonucleoproteins (hnRNPs) not only function in the nucleus but also control the fates of mRNAs in the cytoplasm. Here, we show that hnRNP D plays a versatile role in cytoplasmic mRNA turnover by functioning as a negative regulator in an isoform-specific and cell-type-dependent manner. We found that hnRNP D discriminates among the three classes of AU-rich elements (AREs), most effectively blocking rapid decay directed by class II AREs found in mRNAs encoding cytokines. Our experiments identified the overlapping AUUUA motifs, one critical characteristic of class II AREs, to be the key feature recognized in vivo by hnRNP D for its negative effect on ARE-mediated mRNA decay. The four hnRNP D isoforms, while differing in their ability to block decay of ARE-containing mRNAs, all potently inhibited mRNA decay directed by another mRNA cis element that shares no sequence similarity with AREs, the purine-rich c-fos protein-coding region determinant of instability. Further experiments indicated that different mechanisms underlie the inhibitory effect of hnRNP D on the two distinct mRNA decay pathways. Our study identifies a potential mechanism by which cytoplasmic mRNA turnover can be differentially and selectively regulated by hnRNP D isoforms in mammalian cells. Our results support the notion that hnRNP D serves as a key factor broadly involved in general mRNA decay.

The influence of growth-induced stress from the surrounding medium on the development of multicell spheroids

A mathematical model is adapted to the description of the growth of an avascular tumour spheroid embedded in a deformable medium (gel). Attention is focused on the influence that the mechanical properties of the gel have on the tumour's growth dynamics. Following the work of Landman and Please (2000), the tumour is treated as a two phase material, whereby the tumour cells and the extracellular fluid form distinct phases. Its growth is modelled by combining mass conservation and force balances for each phase with the usual concepts of diffusion limited growth in response to an externally supplied nutrient. The mechanical properties of the gel are characterised by a strain energy function. The stress induced in the gel by the tumour's expansion is incorporated into the force balance equations, thereby linking it to the tumour's growth. Numerical simulations of the model equations show that as the stiffness of the gel increases, the tumour's growth rate and equilibrium size decrease and the time at which necrosis is initiated is delayed (if it occurs at all). Similar results are obtained when the initial size of the tumour is reduced whilst the mechanical properties of the surrounding gel are held fixed. Such results, which are in good qualitative agreement with available experimental data, suggest that mechanical interactions between a tumour and the tissue or medium in which it is located can significantly influence its growth dynamics.

Primitive neuroectodermal tumor of the kidney associated with Budd-Chiari syndrome in a 17-year-old girl

Renal primitive neuroectodermal tumor (PNET) is a rare and highly malignant neoplasm of the kidney. We report the case of a 17-year-old girl with renal PNET that was complicated by Budd-Chiari syndrome. She was admitted due to abrupt left flank pain and gross hematuria. Abdominal sonography and computerized tomography (CT) disclosed a large hemorrhagic left renal mass and thrombus in the inferior vena cava (IVC). Left radical nephrectomy was performed and renal PNET with tumor rupture and tumor invasion into the IVC was diagnosed based on operative findings and histologic features. Tumor cells were positive for neuronspecific enolase, chromogranin-A, and vimentin but negative for cytokeratin, leukocyte common antigen, CD3, and CD20. The thrombus in the IVC extended into the right atrium and caused obstruction of the right and middle hepatic venous outflow, which was evident on follow-up CT scan 5 months later. The patient died due to hepatic failure and progressive cardiovascular compromise 6 months after surgery. This case demonstrates that renal PNET can be life threatening when the tumor thrombus extends into the IVC and causes hepatic outflow obstruction.

Treatment of distal clavicle fracture using Kirschner wires and tension-band wires

BACKGROUND

Nonunion frequently follows distal clavicle fracture. Traditional pinning methods using the through acromioclavicular articulation may result in osteoarthritic changes or ankylosis. This study introduces a direct pinning technique in which the acromioclavicular joint is spared.

METHODS

Twelve patients with displaced distal clavicle fractures received open reduction and fixation with Kirschner wires (K-wires) and tension-band wires, from May 1996 to March 1997. The indication for surgery was type IIa fracture or fracture with displacement. Unrestricted passive and active range of motion was performed as soon as possible after the operation. Stretching and exertional exercises were permitted after radiographs showed an osseous union and after the implants were removed.

RESULTS

Eleven patients achieved osseous union with painless full motion. Union time ranged from 3 to 6 months. One patient suffered from more comminuted fracture because of a fall 2 months after operation. This patient received a revision surgery with distal clavicle resection and coracoclavicle reconstruction. Symptomless ossification around the coracoclavicle ligament was noted on radiographs in one patient. The ossification did not progress after the 9-month follow-up.

CONCLUSION

Edwards reported a rate of 45% delayed union and 30% nonunion in type II fractures. Several techniques had been described in the relevant literature. In our practice, fixation with Kirschner wires and tension-band wires has been successful in the treatment for displaced distal clavicle fracture.

Chronic hepatitis C virus infection associated with primary warm-type autoimmune hemolytic anemia

Autoimmune hematologic abnormalities are not well recognized in chronic hepatitis C virus infection. We demonstrate an unusual association between primary autoimmune hemolytic anemia and chronic hepatitis C virus infection. A 69-year-old woman who had a history of hepatitis C virus-related liver cirrhosis was found to have deteriorating anemia with reticulocytosis when admitted to the hospital. Laboratory work revealed both positive direct and indirect Coombs' tests, and warm-type immunoglobulin G against surface antigens of red blood cells. After prednisolone therapy, her anemia improved dramatically. To our knowledge, this is the first reported case of chronic hepatitis C virus infection linked with autoimmune hemolytic anemia in its natural course, not related to prior interferon treatment. Our report suggests that isolated autoimmune hemolytic anemia may be one of the unusual hematologic manifestations of chronic hepatitis C virus infection.

Applied potential tomography in liquid gastric emptying measurement: design, assembling, calibration, and clinical application

The present study aimed to validate the accuracy of a homemade applied potential tomography (APT) apparatus for liquid gastric emptying (GE). Twelve electrodes were placed in a circular array around the subjects. Ten electrodes in a rotated order recorded electrical current delivered from a driving pair of electrodes. Based on tomography, averaged signals of changed resistivity were constructed to display area changes. Six beakers were respectively placed into a saline-filled Perspex tank to measure their cross-sections. True beaker cross-sections are 2.01, 15.9, 18.8, 30.19, 38.48, and 63.61 cm2, respectively, whereas APT generated cross-sections were 7.9 +/- 2.9, 16.7 +/- 3.3, 22.4 +/- 4.9, 28 +/- 4.8, 48.7 +/- 7.6, 67 +/- 6.1 cm2, respectively (r = 0.98, P < 0.001). Twenty-four healthy males ingested 500-ml test solution to assess GE using both APT and scintigraphy. Only 20 (83.3%) subjects had a successful measurement. The APT half emptying time was 15.6 +/- 4.8 min, whereas scintigraphy was 21.9 +/- 6.3 min (r = 0.67, P < 0.01). In conclusion, our APT apparatus is a simple, noninvasive, and inexpensive way to assess liquid GE. Its clinical usefulness is confirmed using both phantom and human models.

The alkaloids of Artabotrys uncinatus

A novel type of alpha,beta-butenolide alkaloid, uncinine (1), two novel oxoaporphines, artabonatine C (2) and artabonatine D (3), a new oxazoloaporphine, artabonatine E (4), and a new 7,7'-bisdehydroaporphine, artabonatine F (5), along with 25 known alkaloids, were isolated from Artabotrys uncinatus. The structures of 1-5 were determined using NMR and mass spectral data. Atherospermidine and squamolone exhibited cytotoxicity against hepatocarcinoma cancer cell lines (Hep G(2) and 2,2,15), and the activity of some of the alkaloids in an antithrombin assay is also discussed.

Identification and characterization of a high-affinity zinc uptake system in Neisseria gonorrhoeae

A search of the gonococcal genome database using the known zinc-binding protein (znuA) sequences from Escherichia coli and Haemophilus influenzae identified an open reading frame encoding a putative gonococcal ZnuA. The consensus amino acid sequence of this open reading frame possessed a characteristic 30-amino acid histidine-rich metal-binding motif (repetitive HDH sequence) containing 43% histidine and 37% aspartic acid and glutamic acid. Subsequently, two adjacent open reading frames with homology to E. coli and H. influenzae znuB and znuC were located upstream of znuA. When partially purified from sonicated cell-free supernatants by CM-Sepharose chromatography, the mature gonococcal ZnuA had an estimated molecular mass of 38 kDa by SDS-PAGE. The presence of a DNA sequence encoding a 19-amino acid signal peptide and the solubility of the mature ZnuA suggested that this protein was located in the periplasm. Inactivation of the Neisseria gonorrhoeae F62 znuA by insertional mutagenesis resulted in a mutant that had a growth rate lower than that of the wild-type parent strain and that required high concentrations of ZnCl2 (> or = 200 microM) for optimal growth. Using a chemically defined agar medium, the gonococcal ZnuA mutant grew only in the presence of Zn(2+), whereas Mg(2+), Ca(2+), Ni(2+), Fe(2+), Cu(2+), Mn(2+) and Cd(2+) had either no effect or were growth inhibitory.

High-resolution cranial ultrasound in the shaken-baby syndrome

With limited near-field resolution and accessible acoustic windows, sonography has not been advocated for assessing central nervous system injuries in the shaken-baby syndrome. Our purpose was to correlate high-resolution ultrasonographic characteristics of central nervous system injuries in whiplash injuries and the shaken-baby-syndrome with MRI and CT. Ultrasonographic images of 13 infants, aged 2-12 months, with whiplash or shaking cranial trauma were reviewed and compared with MRI in 10 and CT in 10. Five patients had serial ultrasonography and MRI or CT follow-up from 1 to 4 months after the initial injury. With ultrasonography we identified 20 subdural haematomas. MRI and CT in 15 of these showed that four were hyperechoic in the acute stage, three were mildly echogenic in the subacute stage, and that one subacute and seven chronic lesions were echo-free. Five patients had acute focal or diffuse echogenic cortical oedema which evolved into subacute subcortical hyperechoic haemorrhage in four, and well-defined chronic sonolucent cystic or noncystic encephalomalacia was seen at follow-up in two. Using ultrasonography we were unable to detect two posterior cranial fossa subdural haematomas or subarachnoid haemorrhage in the basal cisterns in three cases, but did show blood in the interhemispheric cistern and convexity sulci in two. U1-trasonography has limitations in demonstrating abnormalities remote from the high cerebral convexities but may be a useful adjunct to CT and MRI in monitoring the progression of central nervous system injuries in infants receiving intensive care.

Removal of metal ions and humic acid from water by iron-coated filter media

Iron oxide is an excellent, regenerable adsorbent, and often controls free metals through adsorption reaction. The utilization of heating process for coating iron oxide on sand surface allowed the media to be used in a packed column. Iron-coated sand was investigated for adsorbing metal ions and natural organic matter from water by batch and column experiments. Chemical analysis (energy dispersive analysis of X-ray, EDAX) was used for characterizing the copper and lead adsorption sites on iron-coated sand. From the batch experiment results, the copper and lead ions could be removed simultaneously by the iron-coated sand in the competition adsorption system. The interaction between copper, lead ions and iron oxide on sand surface was primarily the chemical bonds. The maximum adsorption capacities of iron-coated sand for copper and lead were 0.259 mg Cu/g-sand and 1.211 mg Pb/g-sand, respectively. The presence of humic acid led to increase the adsorption of copper and lead. Results from column experiments indicated that the copper ions, lead ions and humic acid could be removed completely before the breakpoint. Consequently, the iron-coated sand may be applied for the adsorption/filtration of metal ions and natural organic matters from water.

Correlation of panic attacks and hostility in chronic schizophrenia

The aim of this study was to investigate the relationship between panic attacks and hostility in patients with chronic schizophrenia. Thirty-two patients with a minimum 2-year history of treatment for schizophrenia were interviewed. The patients took mood stablizers lithium, carbamazepine and valproate adjunctively for hostility and anger attacks. Panic attacks were defined by Structure Clinical Interview of DSM-IV. Severity of psychopathology was assessed by the Hamilton Depression Rating Scale (HDRS) and Brief Psychiatric Rating Scale (BPRS). Functional level was assessed by the Global Assessment of Functioning Scale (GAF). Eight (25%) patients met the diagnostic criteria for panic attacks (DSM-IV) with affective symptoms including hostility and sudden spells of anger. Their HDRS scores were significantly higher (P < 0.01), and GAF scores were significantly lower (P < 0.05) than those of patients without panic attacks. Patients with panic attacks displayed significantly higher hostility in the score of the BPRS (P = 0.01). Those who received higher doses of neuroleptics were more likely to be considered hostile. Multivariate analysis revealed that panic attacks were correlated with more severe depression, greater hostility and lower GAF scores. The results suggest that increased hostility and anger spells may be symptoms of panic attacks, which are overlooked by psychiatrists.

Lung C-fiber CNS reflex: role in the respiratory consequences of extended environmental tobacco smoke exposure in young guinea pigs

Environmental tobacco smoke (ETS) exposure harms the respiratory health of children and is associated with an increased risk of asthma and sudden infant death syndrome (SIDS). The mechanisms by which ETS causes these effects are not understood. We hypothesized that one mechanism is an upregulation of the lung C-fiber central nervous system (CNS) reflex responses, which would result in exaggerated reflex responses of apnea, bronchoconstriction, and mucous hypersecretion. The purpose of this work is to highlight evidence obtained in an animal model of postnatal ETS exposure supporting the hypothesis and present data suggesting that actions of the neuropeptide substance P in the nucleus tractus solitarius (NTS) may contribute. Exposing young guinea pigs to sidestream smoke, the surrogate for ETS, for 5 weeks during the equivalent of human childhood, increased the excitability of afferent lung C fibers and NTS neurons in the CNS reflex pathway and prolonged the expiratory apnea. The findings suggest that an increased excitability of NTS neurons that can augment reflex output may contribute to respiratory symptoms in children exposed to ETS. Besides ETS exposure, substance P can also excite NTS neurons and augment lung C-fiber CNS reflex responses. Others have shown that substance P synthesis in lung C fibers is upregulated by another environmental stimulant, allergen. Thus, an upregulation of the substance P system at NTS synapses could contribute to the increased NTS excitability and enhanced reflex responses to lung C-fiber stimulation, providing a potential mechanism to help explain the association of ETS exposure with respiratory symptoms and SIDS.

Failure of grommet insertion in post-irradiation otitis media with effusion

Nasopharyngeal carcinoma (NPC) survivors with post-irradiation otitis media with effusion (OME; 100 ears) were divided into 2 groups. One group underwent grommet insertion, and the other group was treated by repeated myringotomies plus aspiration to evaluate the outcome of the OME. Computed tomography, magnetic resonance imaging, audiometry, and local checks of the ear, nose, and nasopharyngeal fields were performed to evaluate the sinus and middle ear conditions over a long-term (more than 10 years) follow-up period. The results in these NPC survivors with OME indicated that the prevalence of middle ear complications in the myringotomized group (33%) was less than that in the grommeted group (90%). Grommets alone cannot eradicate inflammation outside the middle ear cavity, but rather, they can aggravate it by superinfection. We therefore recommend that controlling the radiation-induced inflammation in areas such as the ears, nose, sinuses, and nasopharynx is most important. In conclusion, post-irradiation OME should be treated in a different way from conventional OME. Restated, grommet insertion is contraindicated in post-irradiation OME.

Enhancement of the immunity to foot-and-mouth disease virus by DNA priming and protein boosting immunization

Subunit vaccination is effective in eliciting humoral responses to a variety of viral antigens, however, it has not generated persistent protective immunity to foot-and-mouth disease virus (FMDV). In this study, we observed that priming mice with a DNA plasmid encoding VP1 of the FMDV O/Taiwan/97 capsid protein followed by boosting with a VP1 peptide conjugate (P29-KLH) resulted in production of not only high titers of antibodies but also antibodies with FMDV neutralizing activities. Moreover, the mice immunized in this manner cleared the virus from their sera in FMDV challenge experiments. Mice subjected to DNA plasmid priming and P29-KLH protein boosting had relatively higher ratio of IgG2a/IgG1 than those primed and boosted with P29-KLH conjugate. Addition of an oligodeoxynucleotide (ODN) containing immunostimulatory cytosine-phosphate-guanosine (CpG) motifs to P29-KLH conjugate also induced a higher ratio of IgG2a/IgG1 and significantly higher titer of neutralizing antibodies. These results indicate that treating animals with DNA plasmids priming and FMDV antigen(s) boosting may elicit immunity to FMD and this immune response may be augmented by CpG ODN.

Ligand preorganization in metal ion complexation: molecular mechanics/dynamics, kinetics, and laser-excited luminescence studies of trivalent lanthanide complex formation with macrocyclic ligands TETA and DOTA

The molecular mechanics and dynamics calculations, kinetics, and laser-excited luminescence studies were carried out for trivalent lanthanide (Ln(3+)) complexes of macrocyclic polyaminopolycarboxylate ligands TETA and DOTA (where TETA is 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid and DOTA is 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) to further understand the observed thermodynamic, kinetic, and structural properties and to examine how ligand preorganization affects metal ion complexation. Excitation spectroscopy (emission monitored at 614.0 nm) of the (7)F(0) --> (5)D(0) transition of Eu(3+) was used to study the aqueous properties of the Eu(3+)-TETA system. A stopped-flow spectrophotometric method was used to study the formation kinetics of the aqueous Ce(3+)-TETA/DOTA systems in the pH range 6.1-6.7. Molecular mechanics calculation results are consistent with the proposed mechanism of Ln(DOTA)(-) formation, i.e., formation of a carboxylate O-bonded precursor, followed by metal ion moving into the preformed macrocyclic cavity. For Ln(TETA)(-) formation, at least two carboxylate O-bonded intermediates have been predicted and Ln(3+) ion assisted reorganization of the TETA ligand is present. The calculated bond distances and overall structures of Ln(DOTA)(-) and Ln(TETA)(-) were in agreement with the single-crystal and solution NMR structural data. The origin of the difference in thermodynamic stability of Ln(DOTA)(-) and Ln(TETA)(-) complexes and the corresponding formation intermediates is mainly due to the differences in water-occupancy energy (i.e., whether there is an apical coordinated water molecule), the ligand strain energy, and the cation-ligand interaction energy. Kinetic studies revealed that the formation rates of the Ce(TETA)(-) complex are smaller at lower pH and temperature but become greater at higher pH and temperature, as compared to those of the Ce(DOTA)(-) complex. This is attributed to the lanthanide ion and both mono- and di-hydroxide ion assisted TETA conformational reorganization and higher kinetic activation parameters. The presence of a di-hydroxide ion assisted intermediate rearrangement pathway could make the Ce(TETA)(-) complex formation rate faster at higher pH, and the higher activation barrier makes Ce(TETA)(-) complex formation rate slower at lower pH, as compared to those of the Ce(DOTA)(-) complex.

Hydrachine A, a novel alkaloid from the roots of Hydrangea chinensis

A novel alkaloid, hydrachine A (3), has been isolated, along with 15 known compounds, from the roots of Hydrangea chinensis. The structure and stereochemistry of the new alkaloid 3 was determined using extensive 2D NMR data.

Electrogastrographic characteristics in patients of stomach cancer

Using a homemade electrogastrography (EGG) system, we studied the characteristics of myoelectrical rhythm in gastric cancer (GC) patients. Based on a short-term Fourier transform, recorded slow waves could be automatically analyzed to obtain the following parameters: dominant frequency/power, percent of normal rhythm (2.4-3.7 cpm), power ratio, etc. Fifty histologically confirmed GC patients (34 men, 16 women) were enrolled before surgical intervention to measure their fasting and postprandial EGG parameters for 30 min. The cancerous parameters of GC patients were then obtained postoperatively. In addition, 46 healthy subjects were enrolled for comparison. When compared to controls, GC patients had the following characteristics: absence of postprandial increase in dominant frequency (GC: 3.04 +/- 0.47 vs 3.07 +/- 0.44 cpm, NS; controls: 3.02 +/- 0.31 vs 3.21 +/- 0.25 cpm, P < 0.001), marked power response after meal (P < 0.05), and obvious power ratio (4.58 +/- 7.38 vs 2.27 +/- 2.05, P < 0.05). Multivariate analysis indicated that advanced GC was the factor responsible for the obvious dominant power enhancement after meal (P < 0.05). Other demographic, clinical, and cancerous factors did not influence EGG parameters. We conclude that apparent arrhythmia is not encountered in GC patients, although they mainly exhibit obvious postprandial power response. Advanced GC is likely responsible for this power enhancement on EGG recording.

Accumulation and depuration of paralytic shellfish poisoning toxins by purple clam Hiatula rostrata Lighttoot

Purple clams (Hiatula rostrata Lighttoot) accumulated paralytic shellfish poisoning (PSP) toxins produced by a toxic strain of the dinoflagellate Alexandrium minutum Halim for subsequent study of toxin distribution during depuration (detoxification by a nontoxic microalgal diet or starvation). The results confirm the data in the literature concerning the high toxicity of the digestive gland, and the depuration efficiency between feed with nontoxic microalgae and starvation is similar. The toxin profile of the purple clams was similar with that of Alexandrium minutum at the end of the exposure period; GTX4 and GTX1 were dominant. However, at the end of the depuration period, GTX3 and GTX2 were dominant. The non-visceral tissues were toxic after feeding with toxic algae. The toxicity was low and the profile were also similar with that of the toxic algae. No PSP toxins other than GTX-1, 2, 3 and 4 were detected in the experimental period.