Optimally isotropic Laplacian operator.

Laplacian operators used in the literature for digital image processing are not rotationally invariant. We examine the anisotropy of 3 x 3 Laplacian operators for images quantized in square pixels, and find the operator which has the minimum overall anisotropy.

Underwater imaging with a moving acoustic lens.

The acoustic lens is a high-resolution, forward-looking sonar for three dimensional (3-D) underwater imaging. We discuss processing the lens data for recreating and visualizing the scene. Acoustical imaging, compared to optical imaging, is sparse and low resolution. To achieve higher resolution, we obtain a denser sample by mounting the lens on a moving platform and passing over the scene. This introduces the problem of data fusion from multiple overlapping views for scene formation, which we discuss. We also discuss the improvements in object reconstruction by combining data from several passes over an object. We present algorithms for pass registration and show that this process can be done with enough accuracy to improve the image and provide greater detail about the object. The results of in-water experiments show the degree to which size and shape can be obtained under (nearly) ideal conditions.

Quantization error in regular grids: triangular pixels.

Quantization of the image plane into pixels results in the loss of the true location of features within pixels and introduces an error in any quantity computed from feature positions in the image. We derive closed-form, analytic expressions for the error distribution function, the mean absolute error (MAE), and the mean square error (MSE) due to triangular tessellation, for differentiable functions of an arbitrary number of independently quantized points, using a linear approximation of the function. These quantities are essential in examining the intrinsic sensitivity of image processing algorithms. Square and hexagonal pixels were treated in previous papers. An interesting result is that for all possible cases 0.99

Brain cholesterol and phospholipid levels in cyproheptadine treated albino rats.

Effect of different doses (2.5 mg, 5 mg, 10 mg and 40 mg/kg), s.c., for 2 weeks, of cyproheptadine (CYP) on brain cholesterol and phospholipid of albino rats was investigated. Cyp. 2.5 mg/kg, showed increase in brain cholesterol and phospholipid contents whereas other doses caused a decrease in phospholipid level.

[Extramammary carcinoid tumor metastatic to the breast. Apropos of a case]. / Les carcinoïdes d'origine extramammaire métastasiant au sein. A propos d'une observation.

We report the case of a 42-year-woman treated for an appendicular carcinoid tumor with bilateral ovary metastases and mesenteric node involvement. After a systematic mammography, an infraclinical lesion of the breast was detected. Mammographic and echographic images revealed nodular mass with possibly malignant features. Fine-needle aspiration biopsy indicated malignancy. The definitive diagnosis of breast metastasis of a carcinoid tumor was made by biopsy. This case is related to 14 previously published cases. The authors emphasize the importance of making a precise histological diagnosis to avoid overtreatment of a metastatic lesion.

[Cytologic diagnosis of breast angiosarcoma]. / Diagnostic cytologique d'angiosarcome mammaire.

Angiosarcomas of the breast are exceedingly rare tumors that are only infrequently seen by pathologists examining fine-needle biopsy specimens. We report two cases in two women aged 52 and 57 years. Cytologic features are analyzed and differential diagnosis is discussed.

[Diagnosis of bilateral secondary tumors of the kidney. Contribution of cytology. Apropos of 2 cases]. / Diagnostic des tumeurs secondaires bilatérales du rein. Apport de la cytologie. A propos de deux observations.

The authors report bilateral secondary tumors of the kidney in two patients: one previously treated for an epidermoid tumor, the other for an anaplastic bronchial tumor. In both patients, clinical and radiological features were those of a malignant process. Scan-guided percutaneous fine needle aspiration provided the material necessary to make a definitive cytological diagnosis; it was thus possible to assess the malignancy and recognize the histological type of lesions.

[Role of lymph node cytopuncture in the evaluation of cancers of the prostate and bladder]. / Place de la cyto-ponction ganglionnaire dans le bilan des cancers de la prostate et de la vessie.

Lack of reliability of lymphography and morbidity associated with lymphadenectomy lead authors to use lymph node puncture-cytology in assessment of the state of the pelvic nodes in evaluating carcinomas of the bladder and prostate. 38 patients were thus investigated (21 CA prostate and 17 bladder tumours). In 83% of cases the material collected was uninterpretable. Proof of a lymph node metastasis was obtained in 15 cases. 23 cases were further evaluated at surgery, confirming the absence of false positives. 3 false negatives would raise the question of the limitations of the method. The absence of complications would appear to justify this harmless method, with the potential of increasing its reliability by puncture of the majority of opacified nodes regardless of their radiological appearance.

Successful treatment of human non-24-hour sleep-wake syndrome.

The authors report a case in which a non-24-h (hypernychthemeral) sleep-wake cycle appeared as a late complication of a more fundamental disturbance in the quality of sleep (difficulty falling asleep, frequent awakenings, nonrefreshing sleep). The sleep disturbance began abruptly after a series of stressful events. The patient reported that he extended his hours of bedrest in the morning in order to increase his total sleep time and feel mor rested, and that he gradually extended his hours of activity in the late evening in order to increase his drowsiness and ability to fall asleep. At first this behavior, which was a deliberate attempt to compensate for inefficient nighttime sleep, led to a delayed sleep period, as also occurs in the delayed sleep phase syndrome. After several years in which sleep efficiency progressively deteriorated, this behavior led to a non-24-h free-running sleep-wake cycle. After the patient was treated with thyroxine for borderline hypothyroidism, and then flurazepam and finally vitamin B12, his sleep disturbance progressively improved and his sleep-wake cycle shortened. After B12 treatment he was able to advance the timing of ;his sleep period for the first time in nearly 10 years and to follow a normal 24-h sleep-wake regimen.

[Contribution of drill-biopsies to pre-treatment investigation of breast adenocarcinomas (author's transl)]. / Apport de la drill-biopsie dans le bilan préthérapeutique des adénocarcinomes mammaires.

The sensitivity of drill-biopsies (Rousseau's technique) was studied before using them routinely in pre-treatment investigation of breast adenocarcinomas. Results of histological examination, and estrogen (ER) and progesterone (PR) receptors levels obtained preoperatively by this technique, were compared with those from the corresponding mastectomy or tumourectomy specimens in 85 cases. Cytological examination of the various specimens, performed on prints, was used to compare their cellular density. Measurement of receptors included the determination of cytosolic and nuclear sites, and was performed by the single point dextran charcoal method. The limits of positivity established for ER and PR were 10 and 15 fM/mg protein respectively. The results showed sensitivity of 91.8 p. cent for pathology examinations; furthermore, the Scarff-Bloom-Richardson histoprognosis grading could be performed satisfactorily on drill-biopsy specimens. No significant difference was observed between the percentage of positivity for ER and PR from surgical and drill-biopsy specimens. Good correlation existed between values obtained from drill-biopsy and from surgery both for ER (r = 0.86, p less than 10(-5)) and PR (r = 0.86, p less than 10(-5)).

[Cytology in single "cold" thyroid nodules (author's transl)]. / La cytologie et les nodules thyroïdiens isolés et froids.

The authors report their own experience about 242 histocytologic correlations of single "cold" scintiscan thyroid nodules. That is to say 70,5% in malignancies and 91,8% in benign lesions.

[Broncho-alveolar spread in a case of juvenile laryngeal papillomatosis (author's transl)]. / Dissémination broncho-alvéolaire d'une papillomatose laryngée juvénile.

The authors report the case of a 30-year-old man suffering from juvenile laryngeal papillomatosis, recurrent since the age of 4. 23 years later, multiple round opacities were found in the lungs, progressing slowly to excavation. Bronchoscopy with broncho-aspiration provided histological confirmation of the diagnosis of broncho-alveolar spread of the papillomatosis, made on the basis of plain films and tomography.