Objective response detection in the frequency domain

Several different and related measures have been proposed for objective response detection in the frequency domain. We compared magnitude-squared coherence (MSC) to phase coherence (PC) using simulations with specified signal-to-noise ratios (SNRs) and varying numbers of subaverages; the performance measure was area unde a receiver operating characteristic (ROC) curve. MSC was superior to PC; test time required for equivalent performance is about 3 times greater PC than for MSC. MSC performance for a given final SNR increased with the number of subaverages, but reached a plateau at 16 subaverages. Simulations of noise non-stationarity (high-amplitude noise in some subaverages compared to the others) led to decreased performance advantage for MSC over PC. However, weighted averaging restored this advantage. MSC is shown to be a simple algebraic transform of Victor and Mast's (1991) “circular T²” statistic and of two earlier statistics; all have identical statistical power.     

A comparative study of Aldactone and Diane in the treatment of hirsutism

A comparative study has been performed in order to evaluate the relative potency of Diane and Aldactone in reducing hair growth as well as the effect on blood hormone concentrations. Thirty-six women participated in the study and depending on the desire for contraception, 22 were treated with Diane and 14 with Aldactone. The results show that Aldactone (50 mg per day) had little effect on hormone concentrations, only LH was significantly reduced after 12 months of treatment. Despite the lack of effect on hormone levels, all 14 women reported reduced hair growth and after 5 months of treatment, 58% also reported a decrease in the formation in new hair growth. In contrast to the Aldactone treated group, the women on Diane medication demonstrated a marked decrease in circulating hormone levels with a subsequent effect on the hair parameters. The clinical effects were, however, not quite of the same degree as those seen with Aldactone treatment. Approximately 20% exhibited no response for any of the 3 hair-parameters (reduced hair growth, formation of new hair and a change to softer hair). The response time before any effect was observed was also longer than that seen with the Aldactone group. The data suggest that, at the dosages employed, Aldactone has a better clinical effect on the hair parameters despite a lack of effect on circulating hormone levels. One should, however, be aware that Diane contains only 2 mg cyproterone acetate (CPA) and a better effect would most probably have been obtained using a higher dosage of CPA.     

Objective assessment of speech after surgical treatment for oral cancer: experience from 196 selected cases

In 1992, a personal computer-based workstation for speech-digitized analysis was developed in conjunction with Canniesburn Hospital and Edinburgh University to measure all dispersion in speech after surgery for oral cancer. The voices of 196 patients with tumor of the oral cavity were recorded preoperatively and postoperatively. Surgical resection was carefully mapped out on standard diagrams of the oral cavity. Patients' recordings were assessed for conversational understandability by two referees. Patients also self-scored their speech using the Functional Intraoral Glasgow Scale self-questionnaire. Many patients had similar if not identical resections; therefore, 12 homogeneous groups were identified. Functional outcome for speech was correlated with the site and size of resected tissue and with the reconstruction modalities. The original association of an objective, computer-based tool and two subjective assessment tools proved to be the most suitable investigation method for speech. The general pattern was for consistently better speech quality with smaller excisions. The reconstruction modalities did not seem to influence the overall speech quality, as it was related mainly to the extent of surgical demolition. The authors present a detailed correlation between site and size of excision and functional outcome using color multiple-view diagrams for immediate appreciation. Positive and negative prognostic factors were identified in surgery for oral cancer.     

Objective assessment of clonidine analgesia in man and influence of naloxone

Experimental data indicate that clonidine can induce marked analgesia. We characterized this effect in healthy volunteers and investigated possible links with the opioid peptide system by means of naloxone antagonism. According to a cross-over, double-blind, placebo-controlled design, 10 subjects received oral and i.v. placebo or clonidine (0.2 mg p.o.) or clonidine and naloxone (2.8 mg i.v. in 5 h). Analgesia was assessed by measurement of the subjective pain threshold (visual analog scale) and the objective nociceptive flexion reflex (R III) threshold after transcutaneous electrical stimulations. A correlation was observed between subjective and objective thresholds (r: 0.78). Oral clonidine alone or with naloxone increased subjective and objective pain thresholds for at least 4 hours (p less than 0.01, ANOVA). Naloxone tended to reinforce clonidine analgesia. Only moderate and well tolerated side-effects were observed.     

Plasma androgens in idiopathic hirsutism

The plasma concentrations of testosterone, androstenedione,5-androstene-3β, 17β-diol, 5α-dihydrotestosterone and 17β-hydroxy-androgens have been measured in normal women and in patients with idiopathic hirsutism. The mean levels of all the compounds studied were higher in the group of patients with hirsutism than in the controls and apart from dihydrotestosterone, this difference was statistically significant. The correlation between the plasma levels of the various steroids was examined. In the normal subjects, testosterone and androstenedione levels were well correlated, but in the hirsute patients, the correlation is poor. It is suggested that this is related to altered binding of testosterone to plasma proteins in these patients. No one of the steroid levels measured was consistently abnormal in hirsutism, but in 40% of the patients, plasma androstenedione levels were above the normal range.     

Objective assessment of antianginal treatment: a double-blind comparison of propranolol,nifedipine, and their combination.

In a double-blind clinical trial the antianginal effects of nifedipine (30 and 60 mg/day) and propranolol 240 and 480 mg/day) and a combination of both drugs were compared with those of placebo in 16 patients with severe exertional angina pectoris. Response to treatment was assessed by the objective criteria of 16-point precordial exercise mapping and 48-hour ambulatory electrocardiographic monitoring and subjectively by analysis of patients'' daily diaries of episodes of angina and consumption of glyceryl trintrate. The incidence of pain and consumption of glyceryl trinitrate were significantly decreased by each drug compared with placebo, and the combination produced a further significant improvement. Objectively the total area and amount of ST depression on the precordial exercise map and the total number of episodes of ST depression detected on ambulatory monitoring confirmed the efficacy of each treatment regimen; the combination was significantly better than either drug alone (p <0.005). The objective methods permitted greater separation of treatment efficacy and showed reliably that the combination of propranolol and nifedipine was significantly better than either drug alone. Thus this combination is a safe and effective form of treatment for angina.     

Objective assessment of low-contrast computed tomography images with iterative reconstruction

ObjectiveThis study aims to assess low-contrast image quality using a low-contrast object specific contrast-to-noise ratio (CNR_LO) analysis for iterative reconstruction (IR) computed tomography (CT) images.MethodsA phantom composed of low-contrast rods placed in a uniform material was used in this study. Images were reconstructed using filtered back projection (FBP) and IR (Adaptive Iterative Dose Reduction 3D). Scans were performed at six dose levels: 1.0, 1.8, 3.1, 4.6, 7.1 and 13.3 mGy. Objective image quality was assessed by comparing CNR_LO with CNR using a human observer test.ResultsCompared with FBP, IR yielded increased CNR at the same dose levels. The results of CNR_LO and observer tests showed similarities or only marginal differences between FBP and IR at the same dose levels. The coefficient of determination for CNR_LO was significantly better (R² = 0.86) than that of CNR (R² = 0.47).ConclusionFor IR, CNR_LO could potentially serve as an objective index reflective of a human observer assessment. The results of CNR_LO test indicated that the IR algorithm was not superior to FBP in terms of low-contrast detectability at the same radiation doses.     

Objective assessment of low contrast detectability in computed tomography with Channelized Hotelling Observer

PurposeIterative algorithms introduce new challenges in the field of image quality assessment. The purpose of this study is to use a mathematical model to evaluate objectively the low contrast detectability in CT.Materials and methodsA QRM 401 phantom containing 5 and 8 mm diameter spheres with a contrast level of 10 and 20 HU was used. The images were acquired at 120 kV with CTDI_vol equal to 5, 10, 15, 20 mGy and reconstructed using the filtered back-projection (FBP), adaptive statistical iterative reconstruction 50% (ASIR 50%) and model-based iterative reconstruction (MBIR) algorithms. The model observer used is the Channelized Hotelling Observer (CHO). The channels are dense difference of Gaussian channels (D-DOG). The CHO performances were compared to the outcomes of six human observers having performed four alternative forced choice (4-AFC) tests.ResultsFor the same CTDI_vol level and according to CHO model, the MBIR algorithm gives the higher detectability index. The outcomes of human observers and results of CHO are highly correlated whatever the dose levels, the signals considered and the algorithms used when some noise is added to the CHO model. The Pearson coefficient between the human observers and the CHO is 0.93 for FBP and 0.98 for MBIR.ConclusionThe human observers' performances can be predicted by the CHO model. This opens the way for proposing, in parallel to the standard dose report, the level of low contrast detectability expected. The introduction of iterative reconstruction requires such an approach to ensure that dose reduction does not impair diagnostics.     

Low-dose flutamide (125 mg/day) as maintenance therapy in the treatment of hirsutism

OBJECTIVE: To evaluate the safety and efficacy of a low dose of flutamide (125 mg/day) in maintaining the clinical results already obtained using a higher dose (250 mg/day), in women suffering from hirsutism. METHOD: Forty-three women suffering from hirsutism of varying origin received 250 mg/day of flutamide as an initial treatment for 12 months and, subsequently, 125 mg/day of flutamide for an additional 12 months as a maintenance treatment. Hirsutism was evaluated by the Ferriman-Gallwey score, and hair diameter and hair growth rate were determined by a special image analysis processor. Biochemical, clinical and hormonal parameters were evaluated in basal conditions and every 2-6 months. RESULTS: The significant decrease in the hirsutism score, hair diameter and hair growth rate during the initial treatment period was confirmed at the end of the maintenance treatment period. Androgen levels decreased up to the end of the initial treatment period and partially decreased during the maintenance treatment. During the initial treatment period, 4 subjects showed an increase of aspartate aminotransferase and alanine aminotransferase and dropped out. During the maintenance treatment period, no side effects or complications were observed. CONCLUSION: Satisfactory management of hirsutism with flutamide seems to be represented by an initial treatment period using 250 mg/day to achieve satisfactory results, followed by a long maintenance treatment period using 125 mg/day.     

Objective assessment of the cryoprotective effects of dimethylformamide for freezing goat semen

The aim of this work was to assess the cryoprotective effects of dimethylformamide (DMF) for freezing goat semen, using an objective analysis by computer-assisted sperm analysis (CASA). Twenty-one ejaculates (seven per animal) were collected from three stud bucks with the aid of an artificial vagina and immediately evaluated for gross and microscopic characteristics. The semen was diluted in two steps with a Tris–egg yolk extender containing 6% glycerol or 6% DMF, frozen in 0.50-mL straws, and stored in liquid nitrogen. Samples were accessed for sperm morphology, sperm membrane structural and functional integrity, and by CASA, immediately after thawing. There were differences (P < 0.05) between glycerol and DMF with regard to subjective progressive motility (23.9 ± 2.2% vs. 16.6 ± 2.0%), objective progressive motility (3.5 ± 0.4% vs. 1.8 ± 0.3%), linearity (53.9 ± 1.6% vs. 48.1 ± 1.4%) and amplitude of lateral head (2.3 ± 0.1 vs. 2.9 ± 0.1 mm), which confirmed the efficiency of glycerol. In conclusion, dimethylformamide could be used as an alternative cryoprotectant for goat semen freezing. However it was showed that no benefits were derived by using dimethylformamide to replace glycerol at an equal 6% concentration.     

Objective assessment of the cryoprotective effects of dimethylformamide for freezing goat semen

The aim of this work was to assess the cryoprotective effects of dimethylformamide (DMF) for freezing goat semen, using an objective analysis by computer-assisted sperm analysis (CASA). Twenty-one ejaculates (seven per animal) were collected from three stud bucks with the aid of an artificial vagina and immediately evaluated for gross and microscopic characteristics. The semen was diluted in two steps with a Tris–egg yolk extender containing 6% glycerol or 6% DMF, frozen in 0.50-mL straws, and stored in liquid nitrogen. Samples were accessed for sperm morphology, sperm membrane structural and functional integrity, and by CASA, immediately after thawing. There were differences (P < 0.05) between glycerol and DMF with regard to subjective progressive motility (23.9 ± 2.2% vs. 16.6 ± 2.0%), objective progressive motility (3.5 ± 0.4% vs. 1.8 ± 0.3%), linearity (53.9 ± 1.6% vs. 48.1 ± 1.4%) and amplitude of lateral head (2.3 ± 0.1 vs. 2.9 ± 0.1 mm), which confirmed the efficiency of glycerol. In conclusion, dimethylformamide could be used as an alternative cryoprotectant for goat semen freezing. However it was showed that no benefits were derived by using dimethylformamide to replace glycerol at an equal 6% concentration.     

Short‐term assessment of dung beetle response to carbosulfan treatment against desert locust in Sudan

The beneficial role of dung beetles (Coleoptera: Scarabaeidae) is well known. Potential risks to these beetles from the widespread use of insecticides against the desert locust, a significant plant pest in Africa, the Near East and South West Asia, have not been studied previously. Short‐term responses of dung beetles to carbamate carbosulfan (Marshal®, ultra low‐volume formulation, 100 g active ingredient ha^?1) were assessed during desert locust control operations at five sites within two major biotopes: Acacia tortilis shrubland and cultivated wetland; on the Red Sea Coast of Sudan. The study took place during January–February 2004. At each site, fresh dung from Zebu cows was placed in areas targeted for desert locust control. Dung pats were placed in plots in two areas and left for 24 h, before and after insecticide application. Beetles were extracted by floatation. There was a significant decrease in abundance between the pre‐ and post‐spray period in treated areas for the Scarabaeinae species Onthophagus margaritifer (a dark colour morph). In contrast, it was found that Aphodius lucidus and beetles at the subfamily level of Aphodiinae increased in numbers after insecticide treatment. Mortality and sublethal impacts as well as a repellent effect of the insecticide may explain the decrease in Onthophagus margaritifer, while the increase in Aphodiinae beetles could be an indirect response to lower numbers of Scarabaeinae beetles in competing for the same resource. These organisms and the applied methodology may be useful for environmental monitoring of desert locust control, thus further studies are suggested. The assessment also revealed a marked difference between the two biotopes with high abundance and species richness of dung beetles in A. tortilis shrubland, while these measures were low in the cultivated wetland. Five new species of dung beetles for Sudan were found in this study.     

Partial deficiency in 21-hydroxylase in certain forms of hirsutism

The ACTH test is important when hirsutism occurs in women with a slight 21-hydroxylase deficiency, and normal basal 17-OH Progesterone (17-OH-P/plasma levels). Extensive hormonal assays: LH, FSH, Prolactin, 17 beta-estradiol (E2), Estrone, 17OH-P, Androstenedione, Testosterone, Cortisol (C), Dehydroepiandrosterone-S (DEA-S) were carried out in 36 hirsute women. 13 of these presented hormone levels as found in polycystic ovary syndrome (PCOS), 6 women presented a slight 21-hydroxylase deficiency (increased plasma 17-OH-P and decreased C after ACTH test with significant, p less than 0.01, increase of 17-OH-P/C and 17 women presented idiopathic hirsutism (IH). The hormonal pattern, in the basal condition, is not different in IH or in slight 21-hydroxylase deficiency. The ACTH test is able to differentiate between IH and adrenal hirsutism.