METHYLATION STATUS OF BCL6 DISTINGUISHES DNA SAMPLES FROM BENIGN AND MALIGNANT LYMPHOPROLIFERATIVE DISORDERS

INTRODUCTION: Core biopsy of the breast has become the method of choice for tissue diagnosis of screen detected microcalcifications and some mass lesions in many breast assessment centres. Biopsy results are not available until the following day. Imprint cytology of fresh breast core samples allows same-day reporting and patient counselling.
AIM: To determine the accuracy of core imprint cytology when compared with core biopsy diagnosis when used in a breast assessment centre setting.
METHODS: Core imprints (CI) were prepared and reported on all fresh core biopsies (CB) performed at the Sir Charles Gairdner Hospital Breast Centre from May to December 2000. Fresh core samples were placed on a glass microscope slide. Core radiographs were taken for microcalcification lesions (MC). A laboratory technician gently and quickly rolled the cores on the slide with fine forceps. The cores were fixed in formalin, processed and reported next day. The imprint slide was air dried and stained with DiffQuik. CI were reported using four categories: Insufficient, Benign, Indeterminate and Malignant. Counselling and planning for management were possible on the same day in women with malignant diagnoses. Clinicians were advised not to discuss negative or indeterminate CI results with women and to defer to the final CB report.
RESULTS: Cores were performed on 381 lesions. There were 83 carcinomas (38 in MC and 45 in masses) and 56 were called malignant on CI (absolute sensitivity 67.5%; 78.9% for MC and 57.8% for masses). 3 malignancies on CB were negative on CI giving a false negative rate of 3.6%. There were no false positive diagnoses. The predictive value of a benign diagnosis was 95.3%. There were no adverse effects in the histology of CB.
CONCLUSION: CI was an accurate method of providing an immediate diagnosis of malignancy in two thirds of malignancies confirmed on CB.     

Capsaicin-sensitive afferents are involved in signalling transneuronal effects between cutaneous sensory nerves

The aim of the present study was to investigate changes in contralateral nerves associated with peripheral nerve injuries. Transection and subsequent regeneration of the saphenous nerve on one side caused a suppression of the ability of the contralateral saphenous nerve to produce a neurogenic plasma extravasation response. This effect was transient, and was first evident two weeks after injury, reaching its maximum at four weeks, but was no longer detectable at eight weeks. This change was paralleled by a decrease in the content of substance P, a neuropeptide involved in neurogenic plasma extravasation, in the contralateral nerve. The neurotoxin capsaicin was used to deplete the nerve of a subclass of C-fibres, namely the polymodal nociceptor afferents. Pretreatment of the nerve to be lesioned with capsaicin was sufficient to significantly attenuate the changes in the plasma extravasation response and substance P content observed on the contralateral side. The effectiveness of the capsaicin treatment was confirmed by histological examination. These results strongly suggest that changes observed at a site distant from the location of the nerve injury are dependent on the integrity of capsaicin-sensitive C-fibre afferents within the injured nerve. Furthermore, given that the contralateral nerve has commonly been used as the control for an injury conducted on the homologous nerve or muscle on the opposite side of the body, the underlying assumption being that the contralateral nerve remained unchanged, the present findings emphasize the need for separate groups of control animals which have undergone no surgical procedures.     

Affective modulation of the startle response in depression: influence of the severity of depression, anhedonia, and anxiety

BACKGROUND: The amplitude of the startle reflex response is known to be influenced by the concomitant presentation of affect-toned material--if it is positive affect-toned, the reflex is inhibited, and if it is negative affect-toned, the reflex is augmented. Abundant evidence demonstrates the utility of the affect-startle paradigm as a significant tool for measuring both positive and negative emotions. We applied this paradigm to study emotional reactivity in depression, particularly in relation to symptoms of depression, anhedonia, and anxiety. METHODS: Depressed patients (22) and controls (22) were shown a series of film clips, consisting of two clips with positive valence, two with negative valence, and two with relatively neutral valence. The startle response was measured in reaction to the acoustic startle-eliciting stimuli presented three times binaurally during each clip. RESULTS: Highly depressed and anhedonic patients, relative to controls, showed a reduced mood (self-ratings) and a lack of startle modulation in response to affective film clips whereas patients relatively low on depression/anhedonia displayed a reduced mood only with pleasant clips and a normal pattern of affective startle modulation. Anhedonia and depression were highly positively correlated but neither correlated with anxiety. Anxious patients displayed larger reflexes across all clips and showed a reduced mood modulation with pleasant, but not unpleasant, clips. LIMITATIONS: The large majority of patients was medicated with antidepressants which may have influenced the results. CONCLUSIONS. Reactivity to pleasant stimuli is diminished in patients suffering from low levels of depression and/or anhedonia, but reactivity even to unpleasant stimuli seems compromised at high levels of depression and/or anhedonia. Anxiety is associated with hyperstartle responding.     

Cloning and expression of the gene involved in Sanfilippo B syndrome (mucopolysaccharidosis III B)

Sanfilippo B syndrome is caused by a deficiency of alpha-N- acetylglucosaminidase, a lysosomal enzyme involved in the degradation of heparan sulphate. Accumulation of the substrate in lysosomes results in degeneration of the central nervous system with progressive dementia often combined with hyperactivity and aggressive behaviour. In order to clone the deficient gene, we purified the enzyme from human placenta and obtained amino acid sequence information. Alignment of one of the CNBr generated internal peptides to sequence from the database revealed the chromosomal location of the gene in the 5' upstream flanking region of the gene for 17-beta-hydroxysteroid-dehydrogenase at 17q21.1. The available DNA sequence was used to clone the cDNA coding for alpha-N- acetylglucosaminidase and analyse its gene structure. The gene is fully contained in the 5' upstream flanking region of the gene for 17-beta- hydroxysteroid-dehydrogenase and interrupted by five introns. The cDNA clone has a length of 2575 bp and encodes a protein of 743 amino acids. Chinese hamster ovary cells transfected with the cDNA construct show alpha-N-acetylglucosaminidase activity about 17-fold over background. This will allow correction studies with NAG deficient Sanfilippo B cell lines and facilitate the development of enzyme replacement therapy for these patients.      

Paramagnetic macrocyclic complexes as contrast agents for MR imaging: proton nuclear relaxation rate enhancement in aqueous solution and in rat tissues

Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA.     

海南省大劣按蚊实验室自然交配的驯化研究

目的 建立实验室大劣按蚊自然交配繁殖种群,为同类研究提供依据。方法 将野外捕捉并在实验室人工交配繁殖至第61代的大劣按蚊,按不同雌雄比例先后顺序置于大、中、小三种不同型号的蚊笼中喂养、驯化、观察产卵情况并计算产卵数和孵化率。结果 在大、中、小蚊笼内的分别驯化至第15、10和18代时成蚊卵的孵化率各达到82％、83．4％和80．7％,成功建立小蚊笼自然交配的大劣按蚊种群。结论 经实验室驯化的大劣按蚊能够自然交配、产卵、繁殖,有助于建立实验室自然种群。     

甲状腺机能亢进症危险因素病例对照研究

目的 探讨各危险因素与甲亢的关系。方法 对三亚地区110例甲亢采用1：2配比的病例对照研究,资料处理采用条件Logistic回归分析.结果 甲亢发病与下列5因素关系密切：家庭年收入(OR=2．055)、食用碘盐(OR=2．133)、喜食海产品(OR=2．183)、感染(OR=2．382)、家庭生活事件(OR=3．017) 结论 家庭生活事件、感染、喜食海产品、食用碘盐、家庭年收入增高等是甲亢的危险因素。     

海南省性罪错妇女11年性病感染情况调查分析

目的 通过对11年来性罪错人员性病感染情况的调查分析,掌握性病在性罪错妇女中流行的特点,为政府部门对性病防治政策的制定提供科学依据。方法 对1990年元月至2000年12月海南省妇女收容教育所被收教的性罪错妇女进行性病检查,统计其各种性病的发病人数,然后进行分析。结果 11年中共收教4780人,其中感染淋病、非淋菌性尿道炎(宫颈炎)、尖锐湿疣、梅毒、生殖器疱疹、HIV共2967例,阳性率为62．07％,其中非淋菌性尿道炎(宫颈炎)1826例(38．20％)、淋病469例(9、81％)、梅毒414例(8．7％)、尖锐湿疣246例(5．14％)、生殖器疱疹11例(0．23％)、HIV阳性1例(0．02%)。结论 性罪错妇女六种性病的患病率很高,达62．07％,其中非淋菌性尿道炎(宫颈炎)为其主要病种,淋病的患病率逐年下降,梅毒的患病率逐年上升,尖锐湿疣基本稳定,其流行特点值得我们重视。