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J Sarkissian

Publications and source records attributed to J Sarkissian.

10 recordsLinked to original sources
PubMed2001

A test of general relativity from the three-dimensional orbital geometry of a binary pulsar.

Binary pulsars provide an excellent system for testing general relativity because of their intrinsic rotational stability and the precision with which radio observations can be used to determine their orbital dynamics. Measurements of the rate of orbital decay of two pulsars have been shown to be consistent with the emission of gravitational waves as predicted by general relativity, but independent verification was not possible. Such verification can in principle be obtained by determining the orbital inclination in a binary pulsar system using only classical geometrical constraints. This would permit a measurement of the expected retardation of the pulse signal arising from the general relativistic curvature of space-time in the vicinity of the companion object (the 'Shapiro delay'). Here we report high-precision radio observations of the binary millisecond pulsar PSR J0437-4715, which establish the three-dimensional structure of its orbit. We see the Shapiro delay predicted by general relativity, and we determine the mass of the neutron star and its white dwarf companion. The determination of such masses is necessary in order to understand the origin and evolution of neutron stars.

Journal Article↗
PubMed1983

Intravesical instillation of mitomycin C in the prophylactic treatment of recurring superficial transitional cell carcinoma of the bladder.

Twenty-six patients with an elevated recurrence rate of stage O or A bladder tumours were treated prophylactically after transurethral resection (TUR) with short-term intravesical instillations of mitomycin C in a non-randomised study. The data before intravesical chemotherapy (IVC) were taken as the internal control for each patient. Mitomycin C was administered in one course of 10 daily doses of 40 mg, starting 24 to 48 hours after TUR. The average follow-up was 13.9 months before and 28.5 months after IVC. Before IVC, the average number of recurrences was 2.6, with an average recurrence rate of 1 every 5.3 months. After IVC there was no tumour recurrence in 4 patients, with a mean of 12.2 months' follow-up, but there was tumour recurrence in 22 patients. For 17 patients (77%) the free interval averaged 2.3 times longer than the mean interval of recurrence before IVC and for 18 patients (82%) the recurrence rate averaged 3.3 times less than the recurrence rate before IVC.

Aged↗
PubMed1981

[Transrectal ultrasonography of the prostate (author's transl)].

A French instrumentation for transrectal ultrasonography of the prostate by means of a rectal probe containing a rotative transducer is presented. Typical ultrasonographic images are shown. Accurate information on the size of the gland is obtained by this method and adenomas can easily be distinguished from adenocarcinomas. The method might eventually be of considerable value for the screening of asymptomatic subjects and early detection of prostatic cancer.

Adenocarcinoma↗
PubMed1981

Clitoroplasty in intersex: a new technique.

A new technique of reduction clitoroplasty is presented. The procedure consists of a subtotal resection of the shaft of the clitoris with preservation of the dorsal neurovascular bundle of the glans. The purpose is to preserve erogenous glans clitoris and the erection of the crura. The anatomical results in 8 patients were excellent; partial necrosis occurred in a 12-year-old patient. The functional result remains unknown since the children are still young. This technique of clitoroplasty is, as far as we know, the most conservative procedure to date.

Child↗
PubMed1981

[Hypospadias : single stage repair (author's transl)].

One stage hypospadias repair -- 66 cases. The authors used Devine and Horton's technique with some modifications : 1. If the meatus is located forward of the mid penile, a rectangular flap based on the urethral meatus is reflected anteriorly and sutured with the glans flap (Devine and Horton) but when the glans flap does not meet the hypospadic meatus a part of the new urethra, between the tip of the glans flap and the meatus, has a strip of skin as a roof, while the rest of the circumference is raw and unclosed. This strip will form a complete canal by epithelialization. 54 cases : 3 fistulas required further operation. 7 fistulas healed spontaneously, 2 meatal stenosis were treated by a single dilatation. The cosmetic result was excellent in 45 cases, good in 13 cases (the meatus remaining a little short of the tip of the penis). 2. Therefore the authors used a full-thickness skin graft tube only for the more posterior cases in which the meatus was behind the mid part of the penis. 9 cases : 1 good result - 8 fistulas.

Child↗
PubMed1981

[Acute idiopathic scrotal edema in young boy. A report of 16 cases (author's transl)].

Sixteen cases of acute idiopathic scrotal edema are reviewed over an eleven-year period. This clinical entity is fairly common and must be differentiated from testicular torsion and other causes of scrotal swelling, by a minimal pain and a normal testis and cord. The clinical course is short and benign without treatment and without sequela. The etiology for the moment, remains idiopathic perhaps is it a variant of angioneurotic oedema. When testicular torsion cannot be excluded with certainty, the scrotum must be explored; but, if characteristics findings on examination are noted by the surgeon, surgical exploration may be safely omitted.

Acute Disease↗
PubMed1981

[Management of the upper urinary tract in boys with posterior urethral valves (65 cases) (author's transl)].

The authors study the management of the upper tract in 65 boys with posterior urethral valves from 1965 through 1978. Their behaviour has changed with time. At the beginning of their experience they used systematically urinary cutaneous diversion (18 cases : 9 good results -- 4 deaths -- 5 poor results). In a second period they used extensive surgical reconstruction at the same time as with destruction of the valves according to H.W. Hendren. Results were very bad : 5 cases: 1 good result, 3 poor results -- 1 death. During the later years of this study (1973 to 1978) 42 boys were managed by primary destruction of the valves. 22 required only valve ablation and recovered with a good upper tract. 6 severely ill infants who did not respond to valve ablation alone were nephrostomy (2) or ureterostomy (4) diverted (4 good results). In 14 additional patients a ureteral reimplantation was required : 8 successes -- 6 failures. Our experience supports the thesis that after primary resection alone the severely dilated and tortuous ureters usually improve strikingly with time. A period of watchful waiting before undertaking ureteral reimplantation is recommended. Measurements of ureteral pressure also are beneficial in determining the need for surgical intervention (Whitaker). Temporary ureteral diversion has a place in the severely ill patient who has not responded to valve resection.

Child↗