In Vitro Validation of Tissue Doppler Left Ventricular Regional Wall Velocities by Using a Novel Balloon Phantom

Velocity data from tissue Doppler imaging (TDI)can provide valuable information on regional leftventricular wallmotion. Validation of TDImyocardialvelocity measurements has been carried out indirectlyfrom gray- scale M- mode images,and discrepancieshave been reported.Mc Dicken[1] and Miyatake etal[2 ]have reported the accuracy and validity of the TDIsystem using a rotating sponge model.However theoverall motion of the heart should be considered.Inthe present study,we described a new TDI…     

A comparison of the effects on follicular development between clomiphene citrate, its two separate isomers and spontaneous cycles

An investigation of the effects on follicular development of clomiphene citrate and its two isomers En clomiphene and Zu clomiphene given separately was carried out on 19 normally cycling women being treated with donor insemination. All women received clomiphene citrate in the first cycle and, following a washout control cycle, were treated with either En clomiphene or Zu clomiphene alone. The number of follicles present, follicular phase oestrogen secretion and luteal phase pregnanediol excretion were not significantly different when Zu clomiphene cycles were compared with control cycles, but were significantly increased in En clomiphene and clomiphene citrate cycles. It is concluded that the En isomer, which has largely antioestrogenic properties, is the isomer active in inducing follicular development. The oestrogenic properties of Zu isomer did not appear to protect it from the possibly detrimental effects on sperm-cervical mucus interaction observed in both isomers and in the combined preparation.     

微乳液反应法制备磺胺嘧啶银均匀微晶及其质量评价

目的：应用微乳液反应法制备磺胺嘧啶银均匀微晶,并评价其质量。方法：利用磺胺嘧啶钠微乳和硝酸银微乳混合后反应的方法,制备磺胺嘧啶银均匀微晶,用透射电镜观察其形态和大小,以Ｘ－射线衍射分析、红外光谱、核磁共振、差热分析等手段检测磺胺嘧啶银均匀微晶各种理化特性。结果：磺胺嘧啶银均匀微晶的粒径大小约为２～４μｍ,均匀微晶的结晶性好,纯度高。体外抑菌实验表明该品比市售磺胺嘧啶银具有更好的抑菌效果。结论：用微乳液反应法能获得磺胺嘧啶银均匀微晶。     

Cement dermatitis in underground workers during construction of the Channel Tunnel

The construction of the Channel Tunnel is one of the largestcivil engineering projects ever undertaken. The British driveemployed 5900 underground workers, and a number developed dermatitisduring 1990/1991. As a result, the Translink Joint Venture (TLJV)Medical Centre set up a surveillance programme aiming to monitorand investigate the men working closely with cement as wellas other groups of workers with skin problems. Men attendedthe Medical Centre voluntarily and were assessed, includinghistory, examination and patch tests to a series of 15 testsubstances (from the European standard series) where indicated.A programme of education about the hazards of working with cementwas instituted, including leaflets, videos, local newspaperarticles and personal explanation by the Medical Centre staff.Between January 1990 and January 1992, 1138 men were seen atthe Medical Centre regarding their skin and 332 were diagnosedas having occupational dermatitis, past or present. Patch testswere performed on 180 men from all trades. Of the 800 grouters,466 (58 per cent) were assessed and 111 had a history of occupationaldermatitis at some time. Many gave a history of a single episodeof dermatitis during a particularly hot and wet phase of tunnelling.Patch tests performed on 86 grouters showed allergy to chromatein 56 (65 per cent). Of the 466 grouters assessed, 17 per centhad positive patch tests to chromate but men with no skin problemspast or present were not patch tested. Cobalt allergy was oftenfound with chromate allergy (50 out of 56). Allergy to epoxyresin was also found in 30 per cent of grouters who were patchtested. Only three men had to change their occupation becauseof their skin disease. Most cases of occupational dermatitisimproved with regular medical supervision, education and personalprotective measures, with relocation to less exposed work wherenecessary. Many cases cleared as the tunnel entered better terrain.The addition of ferrous sulfate has been shown to decrease thelevel of the allergenic hexavalent chromate in cement and itscompulsory use in Scandinavia has reduced the incidence of cementdermatitis in construction workers. The rest of Europe shouldnow follow the Scandinavian lead and consider legislation tomake cement less hazardous to workers' health.     

Randomized trial of radiation for age-related macular degeneration.

PURPOSE: To assess external beam radiation efficacy for subfoveal neovascularization associated with age-related macular degeneration. METHODS: All patients were evaluated in the same institution. In this prospective trial, 27 eyes (27 patients) with subfoveal neovascularization associated with age-related macular degeneration were randomized to either single fraction radiation (750 centigray) or observation. Endpoints were assessed by fluorescein angiography and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity. Examiners were masked to patient treatment status. Parametric and nonparametric statistical analyses were performed. RESULTS: Twenty-seven patients were entered into the trial with a mean age of 76 years (range, 64 to 89) and a mean follow-up of 17 months (range, 7 to 32). The visual acuity loss was slightly less in the irradiated group, a finding of borderline significance (P < .046). There was no significant difference in fluorescein angiographic evidence of subretinal neovascular membrane change in the control group vs the irradiated group. CONCLUSIONS: External beam radiation, at this dose and fractionation, did not appear harmful. There was slightly less visual loss in irradiated eyes. No difference in fluorescein angiographic characteristics of subfoveal neovascularization size or progression in eyes with age-related macular degeneration was noted.     

Cardiovascular changes during morphine administration and spontaneous withdrawal in the rat

Morphine maintenance doses of 10 mg kg(-1) day(-1), 20 mg kg(-1) day(-1) and 30 mg kg(-1) day(-1) were administered to three groups of rats via miniosmotic pumps for 7 days to induce physical dependence. They were then allowed to undergo spontaneous withdrawal. Radiotelemetric blood pressure measurements showed that morphine increased systolic and diastolic blood pressure on the first day of morphine treatment and produced a dose dependent decrease in heart rate, systolic and diastolic blood pressure thereafter. After the peak depressive effect, development of tolerance to morphine was observed in systolic and diastolic blood pressure, but not in the heart rate. During spontaneous withdrawal, both systolic and diastolic blood pressure increased beyond pre-morphine levels for all doses and there was a rebound increase in heart rate at the 30 mg kg(-1) day(-1) dose. These results suggest that the improved sensitivity of telemetric measures combined with the use of minipumps for morphine treatment provide an animal model of spontaneous opioid withdrawal.     

Economic costs of functional dyspepsia

Dyspepsia is defined as chronic or recurrent symptoms believed to originate in the upper gastrointestinal tract. When routine investigation results in no identifiable explanation for those symptoms patients are labelled as having functional dyspepsia. In community-based surveys, approximately 30% of the otherwise apparently healthy population report dyspeptic symptoms and the majority are believed to have functional dyspepsia. Although only 1 in 4 or 5 patients make use of healthcare resources, this patient category is one of the largest in ambulatory care (1.6 to 5% of all consultations in general practice). The annual frequency of consultations for functional dyspepsia in Sweden has been estimated at 47 per 1000 population. In consequence of its high prevalence and associated absenteeism, the total costs of functional dyspepsia are considerable. In Sweden in 1981, the costs were estimated at $US55 000 per 1000 population ($US113 630 in 1991 dollars). The most cost-effective management strategy remains to be defined. Evidence is accumulating that the traditional 'wait-and-see' policy with initial empirical therapeutic trials without investigation may not be the most cost conserving strategy.     

Involvement of the proliferating cell nuclear antigen (PCNA) in DNA repair induced by alkylating agents and oxidative damage in human fibroblasts

The involvement of the proliferating cell nuclear antigen (PCNA) in the process of DNA repair induced by alkylating agents or by oxidative damage was investigated in human quiescent fibroblasts by immunofluorescence and flow cytometry. Transition from soluble to the DNA-bound form of PCNA, was taken as the parameter to determine its involvement in repair DNA synthesis. Treatment with the alkylating agents methylmethane sulfonate and N-methyl-N'-nitro-N-nitrosoguanidine resulted in the rapid and dose-dependent increase in the nuclear binding of PCNA. Similar results were obtained with compounds such as hydrogen peroxide or tert-butyl hydroperoxide, which are known to induce oxidative DNA damage. Tert-butyl hydroperoxide may also generate malondialdehyde through a reaction of lipid peroxidation. This mutagenic and carcinogenic product has been previously shown to form adducts with DNA. Therefore, the possibility that tert-butyl hydroperoxide could induce DNA damage through this pathway was investigated by incubating cells directly in the presence of malondialdehyde. Such treatment resulted in an increase in immunofluorescence associated with nuclear-bound PCNA. The ability of oxidative and alkylating agents to induce the nuclear binding of PCNA was also assessed in proliferating cells. In these conditions, treatment with hydrogen peroxide or methylmethane sulfonate, resulted in an increase in nuclear-bound PCNA in the G1 and in the G2 + M compartments, but not in S phase. At longer times after treatment, PCNA immunostaining was reduced to basal levels, while an increase in nuclear binding of p21(waf1/cip1) protein was found in concomitance with cell-cycle arrest. These results indicate that agents inducing DNA base alterations in vivo, promote the nuclear binding of PCNA. These lines of evidence support the role of a PCNA-dependent reaction in the base excision repair system.      

Effect of the viable-yellow (A(vy)) agouti allele on skin tumorigenesis and humoral hypercalcemia in v-Ha-ras transgenic TGxAC mice

We previously reported that papillomas can arise from the follicular epithelium of v-Ha-ras transgenic TGxAC mice. Since the viable-yellow mutation (A(vy)) of the mouse agouti gene which regulates coat color pigmentation by acting within the micro-environment of the hair follicle has been shown to function as a tumor promoter in the liver, we hypothesized that it may also play a role in TGxAC skin tumorigenesis. Endogenous agouti protein product was detected in the outer root sheath of anagen hair follicles following plucking of the hair shaft, but not in the interfollicular epithelium, in TGxAC mice on an FVB/N genetic background. It was also detected in papillomas from these mice produced by 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment or plucking. Expression of the A(vy) allele in the v-Ha-ras transgenic TGxAC mouse line results in an approximately 2-fold increase in papilloma development compared with controls which did not carry the A(vy) allele following twice-weekly treatment with 1.25, 2.5 or 5.0 microg TPA. In addition, TPA-treated, papilloma-bearing F1 mice which carried the A(vy) allele, but not F1 mice which did not carry the A(vy) allele, exhibited a syndrome of humoral hypercalcemia mediated by parathyroid hormone-related protein (PTHrP) that led to weight loss, hypercalcemia and hypophosphatemia. Thus, we conclude that the A(vy) allele can influence the development of skin tumors and PTHrP-mediated humoral hypercalcemia in v-Ha-ras transgenic TGxAC mice.