Biomedical subjects

D Polyzos

Publications and source records attributed to D Polyzos.

10 recordsLinked to original sources

PubMed2004

An iterative effective medium approximation (IEMA) for wave dispersion and attenuation predictions in particulate composites, suspensions and emulsions.

In the present work we deal with the scattering dispersion and attenuation of elastic waves in different types of nonhomogeneous media. The iterative effective medium approximation based on a single scattering consideration, for the estimation of wave dispersion and attenuation, proposed in Tsinopoulos et al., [Adv. Compos. Lett. 9, 193-200 (2000)] is examined herein not only for solid components but for liquid suspensions as well. The iterations are conducted by means of the classical relation of Waterman and Truell, while the self-consistent condition proposed by Kim et al. [J. Acoust. Soc. Am. 97, 1380-1388 (1995)] is used for the convergence of the iterative procedure. The single scattering problem is solved using the Ying and Truell formulation, which with a minor modification can accommodate the solution of scattering on inclusions in liquid. Theoretical results for several different systems of particulates and suspensions are presented being in excellent agreement with experimental data taken from the literature.

Journal Article↗

PubMed2004

Uterine adnexal torsion: pathologic and gray-scale ultrasonographic findings.

INTRODUCTION: Uterine adnexal torsion is a rare and potentially lethal condition that may arise most unexpectedly in women of any age. It may be partial or complete, the later often resulting in necrosis, gangrene and peritonitis if untreated. The purpose of the study was to determine the spectrum of the histologic and gray-scale sonographic pictures in a series of surgically proven cases of uterine adnexal torsion. METHODS: The study population for the pathologic analysis of twisted uterine adnexa included 92 patients with surgical confirmation of torsion of the uterine adnexa; all the patients were treated radically. All the pathology records were reviewed retrospectively over a 10-year period (from 1992 to 2002) by the coding of ovarian, fallopian tube or adnexal torsion. The gray-scale sonographic findings were analysed in 20 patients who underwent sonographic examination before surgery and adnexal torsion was confirmed at surgery. RESULTS: Neoplasms constituted 46% (42/92) and cysts formed 48% (44/92) of all the twisted uterine adnexa. Normal-sized twisted adnexa were found in five patients (5%) while in one patient simultaneous torsion of both normal fallopian tubes was found (1%). The prevalence of the twisted neoplasms was 16 mature teratomas, nine serous cystadenomas, five mucinous cystadenomas, three serous borderline carcinomas, two fibroma/thecomas, two mucinous borderline carcinomas, two malignant granulosal-stromal cell tumours, one malignant dysgerminoma, one immature teratoma and one clear cell adenocarcinoma. The twisted cysts were 18 serous cysts, 11 paraovarian cysts, nine corpus luteum cysts, three hydrosalpinges, one mucinous cyst and one endometrioma. In one case the torsion of the right ovary was due to hyperstimulation of the ovaries with gonadotropin therapy for IVF treatment. Gray-scale sonographic examination demonstrated cystic lesions in 80% (16/20), solid masses in 5% (1/20) and normal adnexa in 15%; cul-de-sac fluid was present in 55% (11/20). Laparotomy revealed reactive cul-de-sac fluid in ten of these cases (50%) and haemoperitoneum in one (5%). CONCLUSION: Adnexal torsion is most commonly associated with benign processes (89%) and usually occurs in patients under 50 years old (80%). The spectrum of sonographic findings varies due to the adnexal pathology, the degree and the duration of adnexal torsion.

Adnexal Diseases↗

PubMed2004

Internal hemorrhage caused by a twisted malignant ovarian dysgerminoma: ultrasonographic findings of a rare case and review of the literature.

PURPOSE: Ovarian cancer presents as an acute abdomen very rarely. The purpose of the study is the description of a right ovarian malignant dysgerminoma presenting as an abdominal emergency. CASE: A 16-year-old white female presented with acute abdominal pain in the right iliac fossa. On physical examination the abdomen was acute and a mass in the right lower abdomen was palpated. The patient was sexually active and bimanual gynecological examination revealed the presence of a large lobulated solid tumor in the position of the right adnexa. Ultrasound examination showed the presence of a large, multilobulated, heterogeneous, predominantly solid pelvic mass. Color flow imaging showed intratumoral flow signals. The uterus and the left ovary had normal size and echo-texture. Fluid was found in the cul-de-sac and in Morisson's space. An immediate exploratory laparotomy exposed the presence of a twisted right ovarian mass and intraperitoneal hemorrhage. A superficial tumoral vessel actively bleeding was seen. Peritoneal fluid was obtained for cytology. The intra-abdominal hemorrhage ceased when the ovarian pedicle was clamped. The patient underwent right salpingo-oophorectomy and biopsy of the omentum. Pathologic analysis revealed a malignant dysgerminoma of the right ovary, expanding to the mesosalpinx. Cytology was positive for malignancy. Postoperative CT scan of the upper and lower abdomen was negative. The patient was assigned to FIGO Stage IIC and referred for platinum-based chemotherapy. CONCLUSION: Ovarian malignant dysgerminoma may present as an acute abdomen because of torsion, passive blood congestion, rupture of superficial tumoral vessels and subsequent intra-abdominal hemorrhage. Ovarian dysgerminoma should be part of the differential diagnosis in a young woman with acute surgical abdomen and a solid heterogeneous pelvic mass detected by ultrasonographic scan.

Abdomen, Acute↗

PubMed2003

Effects of tamoxifen on the human female genital tract: review of the literature.

Tamoxifen is a non-steroidal triphenylethylene derivate, with clear antioestrogenic effects on the breast, that is orally administrated for the treatment of breast cancer and its prevention in a high-risk population. This article analyzes the effects of tamoxifen on the adult human female genital tract and considers its carcinogenicity in the gynaecological reproductive organs. It has been found that tamoxifen causes oestrogenic changes of the vaginal and cervical squammous epithelium and increases the incidence of cervical and endometrial polyps. The action of tamoxifen on the human endometrium in postmenopausal women is connected with simple oestrogenic effects including hyperplasia, while in others with endometrial cystic atrophy. In cases where tamoxifen induces endometrial polyps and hyperplasia, the extensive fibrosis accounts for difficulties in obtaining endometrial biopsy or resecting the polyps. In premenopausal patients tamoxifen disrupts the menstrual cycles and causes ovarian cysts, while in postmenopausal patients it induces ovarian cystic tumors and endometriomas. Also, postmenopausal patients treated with tamoxifen may develop endometriosis, adenomyosis and leiomyomata. In addition, randomized trials have shown a link between tamoxifen use in breast cancer patients and the development of endometrial carcinomas. Moreover, of note is the fact that the association of tamoxifen therapy with uterine mesenchymal neoplasms is higher than expected. In conclusion, the most worrying gynaecological side-effect of tamoxifen is the well-known increased risk of endometrial carcinomas. Women with breast cancer treated with tamoxifen should undergo annual gynaecological examination, but endometrial sampling should be obtained only in the event of endometrial bleeding.

Administration, Oral↗

PubMed2003

Tubo-ovarian abscesses: spectrum of sonographic findings with surgical and pathological correlations.

OBJECTIVE: Pelvic inflammatory disease (PID) is a serious condition that can lead to abscess formation. The purpose of this study was to identify the different sonographic markers on gray scale and color Doppler sonography in tubo-ovarian abscesses. MATERIAL AND METHODS: The study group consisted of 25 women in whom the presence of tubo-ovarian abscess was confirmed by surgery and histopathology and their ultrasound records were analyzed retrospectively. RESULTS: Presence of a mass was found in all cases. The maximum diameter of the mass was 5 cm in two cases and between 5 cm and 10 cm in 23 cases. The mass was demonstrated at the anatomic position of the ovary in 21 cases (84%) and at the cul-de-sac in four cases (16%). The mass was a simple cyst in two cases (8%), in four cases it was cystic with diaphragms (16%), in four cases it was a thickened tube-shaped structure with multiple internal echoes (16%) and in 15 cases it was a mixture of cystic and solid elements (60%). Pyosalpinges with fluid-fluid levels were found in two cases. Fluid in the cul-de-sac was observed at a rate of 48%. Color Doppler sonography demonstrated abundant blood flow in the borders and the septa of the tuboovarian abscesses in 90% of the studied cases. CONCLUSION: The ultrasonographic findings of tubo-ovarian abscesses are not specific. The presence of a mass at the anatomic position of the ovary or at the cul-de-sac in combination with an increased number of white blood cells, elevated erythrocyte sedimentation rate and clinical findings are helpful for a correct diagnosis. Also, the color Doppler flow can further characterize the nature of the pelvic mass by detecting a significant rich blood flow in most cases of tuboovarian abscesses.

Abdominal Pain↗

PubMed2003

Clinical considerations and sonographic findings of a large nonpedunculated primary cervical leiomyoma complicated by heavy vaginal haemorrhage: a case report and review of the literature.

Leiomyomas of the uterine cervix are uncommon. Cervical leiomyomas in non-pregnant women rarely are of clinical significance and their complications include pressure effects on the bladder or urethra, degenerative phenomema and menorrhagia. We present a case of 46-year-old female, gravida 2, para 1 who was presented in the gynaecological emergency room with the chief complaint of profound vaginal bleeding over the previous three weeks with recent passage of clots. Pregnancy test was negative. She suffered from profound orthostatic hypotension and tachycardia. On examination, her abdomen was soft, non-tender, and without rebound, guarding or palpable masses. Bimanual examination was notable for the presence of a large firm mass fixed to the uterine cervix. The cervix was 8 cm dilated and the body of the uterus was felt separate from the mass. The sonographic findings were consistent with a large cervical leiomyoma. Subtotal hysterectomy with salpingo-oophorectomy was performed and the patient's postoperative course was uneventful. In conclusion, in the present case the cause of the heavy vaginal bleeding was a primary cervical fibroid as the uterus attempted to abort it.

Fallopian Tubes↗

PubMed2003

Torsion of a non-gravid leiomyomatous uterus in a patient with myotonic dystrophy complaining of acute urinary retention: anaesthetic management for total abdominal hysterectomy.

Torsion of a pregnant uterus is rare, but torsion of a non-pregnant uterus is extremely rare. Abdominal pain is the major symptom. Other symptoms include vaginal bleeding, urinary tract symptoms and gastro-intestinal manifestations. We present a case of a 37-year-old white nullipara who presented at the emergency room with acute urinary retention. Medical history revealed that the patient carried the disease of myotonic dystrophy, which was diagnosed two years before. Physical examination revealed a tender, distended bladder, which was easily catheterized, draining 900 ml of clear urine. The abdomen was soft with no muscle guarding or rebound tenderness. A palpable large dense mass occupying the cul-de-sac was found during bimanual examination. Abdominal ultrasound examination revealed a large intramural leiomyoma approximately 10 cm in diameter, in the posterior wall of the uterus, which repelled the bladder. In neurological examination the muscular tone and reflexes were reduced in the lower extremities. Myotonic phenomenon was not found. The patient was thought to suffer from myotonic dystrophy and therefore the possibilities for pulmonary and cardiac complications or malignant hyperthermia had to be kept in mind during the anaesthetic management. The patient underwent an exploratory laparotomy and the uterus was found to have undergone a 60 degrees rotation along the corpus and the cervix uteri transition line. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was perfomed. The intra- and postoperative course of the patient was uneventful. In conclusion, in this patient the uterine pathology (large leiomyoma) in combination with the disease of myotonic dystrophy seemed to be the predisposing factors for the torsion of the non-pregnant uterus. Also, the anaesthetic implications for total abdominal hysterectomy in myotonic dystrophy are discussed and the international literature is reviewed.

Adult↗

PubMed2003

Ruptured tubo-ovarian abscess as a complication of IVF treatment: clinical, ultrasonographic and histopathologic findings. A case report.

Tuboovarian abscess is a rare complication of IVF treatment, which can be lethal on rupture. Hereby, we present a case of a ruptured tubo-ovarian abscess, following transvaginal ultrasound-guided oocyte retrieval for IVF and transcervical embryo trasfer in a 38-year-old white female patient with five years of primary infertility who underwent aspiration of bilateral hydrosalpinges at the time of oocyte retrieval. This case suggests that the reactivation of latent pelvic infection due to a previous pelvic inflammatory disease (PID) was the possible route of infection after transvaginal ultrasound-directed follicle aspiration--transcervical embryo transfer. We conclude that physicians should consider the diagnosis of tubo-ovarian abscess in the differential diagnosis of abdominal pain, fever and leukocytosis after ovum retrieval and transcervical embryo transfer for IVF treatment. Preservation of the uterus and unaffected uterine adnexa should be attempted in such cases if future pregnancy is desired.

Abscess↗

PubMed2003

A voluminous twisted paraovarian cyst in a 74-year-old patient: case report and review of the literature.

Although paraovarian cysts rarely cause symptoms, they may be complicated due to massive size, torsion or internal haemorrhage from rupture. Moreover, benign or malignant neoplasms may occasionally develop in paraovarian cysts. The risks from voluminous ovarian or paraovarian cysts are due to severe cardiovascular, pulmonary, and circulatory problems including surgical and postoperative complications. We present a case of a 74-year-old patient who suffered from a twisted voluminous right paraovarian cyst. Her preoperative respiratory function required attention. The patient was treated surgically with good results and she showed notable improvement of her respiratory function, postoperatively. The maximum diameter of the mass was 26 cm and its total weight was 5,100 g. In addition, a simple cyst was found in the left ovary with a maximum diameter of 9.5 cm and total weight of 300 g. In conclusion, paraovarian cysts, even in elderly patients, can reach large sizes requiring awareness of the problems that these large masses may cause.

Abdominal Pain↗

PubMed2002

Ultrasonographic and computed tomography manifestations of intussusception secondary to primary non-Hodgkin's lymphoma diagnosed in puerperium: report of a case and review of the literature.

Non-Hodgkin's lymphoma is infrequently diagnosed during pregnancy and puerperium. A 21-year-old woman, para II, gravida II, on the seventh postpartum day arrived at the Emergency Gynaecologic Clinic complaining of colicky abdominal pain associated with bilious vomiting. A large tender mass of firm consistency was palpated in the midline towards the left hypochondrium. A CT scan of the upper abdomen showed thickened small bowel with halo, specifically at the junction of the jejunum with the ileum, resembling imaging of intussusception. Also, blocks of mesenteric and paraortic lymph nodes and multiple lymph nodes inducing enlargement of the anterior mediastinum were found. These findings rendered a picture of lymphoma in Stage at least III. Subsequent exploratory laparotomy confirmed our preoperative diagnosis. Histopathological examination of the lymph node biopsies established the diagnosis of a primary non-Hodgkin's lymphoma. Judging from the extent of the non-Hodgkin's lymphoma in our patient seven days after delivery the disease probably already existed during the last trimester of pregnancy. This study demonstrates a remarkable delay in diagnosis of non-Hodgkin's lymphoma in pregnancy. The diagnostic dilemmas of non-Hodgkin's lymphoma during pregnancy are emphasized and the literature is reviewed.

Abdominal Pain↗