Phase transitions in electrorheological fluids using molecular dynamics simulations

A parametric study of the properties of electrorheological fluids is conducted using molecular dynamics (MD) simulations. The MD model is based on the solution of the Langevin equation for a number of suspended particles. The equations of motion include inertial effects, polarization forces, Stokes' drag, short range repulsion, and Brownian forces. Different polarization forces are considered to include the effect of enhancements at short range due to multipole moments induced by the suspended particles and other effects. The model is used to investigate the structural changes induced by external electric fields and by shear strains imposed on the system. The response times are studied as a function of two characteristic parameters describing the physical status of the system (temperature and external electric field). Finally, the stress-strain characteristics are studied and the yield stress is calculated as a function of the external electric field. The simulated response is compared with experimental findings.

Management of the abnormal papanicolaou smear during pregnancy: lessons for quality improvement

OBJECTIVE

Our goal in this study was to evaluate the management of pregnant patients with abnormal Papanicolaou smears.

MATERIALS AND METHODS

We reviewed the records of 292 patients undergoing colposcopy to evaluate abnormal cervical cytology during pregnancy.

RESULTS

A total of 32 (11%) of the subjects had Papanicolaou smears demonstrating atypical glandular cells of undetermined significance; 178 (61%) had low-grade squamous intraepithelial lesions; 69 (23.6%) had high-grade squamous intraepithelial lesions; and 2 (1%) had a malignancy. The first colposcopy was performed most commonly during gestational week 24. Colposcopy showed findings consistent with minor changes in 154 cases (53%) and with major changes in 61 (21%). Only 27 patients (9% of the total) underwent a colposcopically directed biopsy, and 51 (83.6%) of the 61 patients with a colposcopic impression of cervical intraepithelial neoplasia grade 2 or greater did not undergo biopsy. Only 24 (26%) of the 91 patients scheduled for follow-up colposcopy during pregnancy complied, and 123 of the 292 patients (42%) returned for follow-up examinations after delivery. Four patients had an invasive cervical carcinoma diagnosed in the 12 months immediately after delivery. Although the first intrapregnancy colposcopy in two of these patients noted findings consistent with cervical intraepithelial neoplasia grade 2 or greater, none of the four underwent biopsy during pregnancy.

CONCLUSIONS

Evaluation of cytological abnormalities is frequently suboptimal during pregnancy. The threshold for colposcopically directed biopsy is often modified during pregnancy in a way that may be harmful to the patient. Extra effort is needed to tailor follow-up to the patient's need and to improve patient compliance.

Our experience on the association of a new physical and medical therapy in patients suffering from induratio penis plastica

OBJECTIVES

To check the efficiency of shock waves in the treatment of induratio penis plastica. The Minilith SL1, successfully used in orthopedic or salivary stones because of its lithotriptic power, can be used to break plaques in Peyronie's disease.

METHODS

A total of 130 patients affected with Peyronie's disease were entered into a prospective trial. Patients with completely calcified plaques as determined by ultrasound evaluation were excluded. We divided the patients into three treatment groups: (A) shock waves alone in 21 patients; (B) a combination of shock waves and verapamil (perilesional injection) in 36 patients, and (C) verapamil alone in 73 patients. First, we treated all groups A and B patients 3 times, 20 min each time, with a Minilith SL1, and then only the patients of the second group received a complete cycle of twelve injections of verapamil (10 mg) every 2 weeks for 6 months. The group of 73 patients (group C) treated during the previous 2 years with a medical therapy (only injection of verapamil) was used as a control group.

RESULTS

Ultrasound evaluation showed a reduction of plaque in 11/21 group A patients and 7/36 group B patients. The treatment was tolerated very well and only 11 petechiae in some patients were noticed after ESW treatment.

CONCLUSIONS

The therapeutic association of shock waves with verapamil injection is an effective nonoperative treatment for the stabilization of Peyronie's disease.

Intralesional injection of triamcinolone in the treatment of lichen sclerosus

OBJECTIVE

To assess intralesional vulvar injections of triamcinolone as an alternative to using topical treatment.

STUDY DESIGN

This was an open trial, in eight patients, of intralesional injection of triamcinolone in patients with symptomatic lichen sclerosus who could not use primary topical treatments. The patients' pretreatment and posttreatment clinical symptoms and gross physical findings were reviewed. In some patients pretreatment and posttreatment biopsies were performed.

RESULTS

There was a decrease in severity scores in the categories of symptoms and physical findings. In four patients who consented to posttreatment biopsy, there was a decrease in severity scores on histopathologic findings.

CONCLUSION

Intralesional injection of triamcinolone hexacetonide into sites of vulvar lichen sclerosus seems to be an effective alternative to using topical agents.

Nutritional survey of children and adolescents with myelomeningocele (MMC): overweight associated with reduced energy intake

In patients affected by MMC both neurological and systemic dysfunctions may cause obesity and malnutrition. The aim of this study is a nutritional survey, with anthropometric assessment and dietary evaluation, of patients affected by MMC.

CLINICAL MATERIALS AND METHODS

Anthropometric assessment, dietary evaluation, and a comprehensive assessment of motor impairment degree (MID) were performed in 100 patients (54 males, 46 females) affected by MMC aged from 6 to 228 months (median 91 months).

RESULTS

Fifty-five/100 children and adolescents with MMC were classified as normal or wellnourished and 5 at risk of malnutrition or malnourished, while another 40/100 patients were classified as marked overweight (weight-for-height or BMI above the 95th percentile). Deficit in height-for-age was observed in 34/100 patients; 12 of these patients presented with obesity. Dietary assessment evidenced that the majority of wellnourished patients (48/55) were consuming less than 80% or between 80% to 100% of recommended daily allowances (RDA) of energy. Overweight patients had an energy intake lower than their own RDA: 5 below 80%, 25 between 80% to 100%, and only 10 over 100% of RDA of energy for age and sex. No statistical correlation was found between nutritional status and MID, while there was a statistically significant difference between nutritional status and dietary intake (p = 0.005).

DISCUSSION

Overweight is the most frequent nutritional disease in patients affected by MMC. Since in our experience on correlation with MID was found, we can speculate that childhood and adolescent obesity in patients with MMC occurs as a result of complex interactive factors, not strictly related to energy intake and MID. Nutritional surveillance and specific treatment programs for overweight MMC patients are essential to enhance their quality of life.

Pre-operative evaluation of cervical adenopathies in tumours of the upper aerodigestive tract

BACKGROUND

Carcinomas of the upper aerodigestive tract are characterized by a high incidence of local metastasis in the neck. The presence of lymph node metastasis represents the most unfavorable prognostic factor for these tumors. A diagnostic routine is needed in order to identify the highest number of neck metastasis, thereby optimizing the selection of patients eligible for surgical neck treatment and reduce costs and length of hospital stay.

MATERIALS AND METHODS

Our study analyzes the sensibility, specificity, and diagnostic accuracy of clinical examination, echography (US), computed tomography (CT) in cervical metastasis detection by comparing them with the histopathological examination of the neck dissection specimens (pN) in 53 patients suffering from carcinoma of the upper aerodigestive tract.

RESULTS

Clinical examination: sensibility 82.1%; specificity 80%; diagnostic accuracy 81.1%; US with a cut off point for minimal adenopathy diameter of 0.5 cm 92.8% sensibility, 60% specificity, 77.3% diagnostic accuracy; US with cut off point 1 cm 82.1% sensibility, 80% specificity, 81.1% diagnostic accuracy; US with cut off point 1 cm, also considering round shape or multiplicity of the adenopathy: 82.1 sensibility, 80% specificity, 81.1% diagnostic accuracy; CT with cut off point 0.5 cm: 92.8% sensibility, 32% specificity, 64.1% diagnostic accuracy; CT with cut off point 1 cm: 85.7% sensibility, 64% specificity, 75.4% diagnostic accuracy; CT with cut off point 1 cm, also considering central necrosis, extracapsular spread, multiplicity of the adenopathy 89.2 sensibility, 60% specificity, 75.5% diagnostic accuracy.

CONCLUSIONS

By relating the results obtained from preoperative methods to the anatomopathological analysis of the surgical specimens we can draw the following conclusions: a) a neck positive to palpation in a subject with carcinoma of the upper aero digestive tract must be submitted to neck dissection. Such patients have an 81.1% likelihood of having a metastasis. In these patients the use of radiologic studies of the neck must be restricted to cases with uncertain involvement of retropharingeal, mediastinic, paratracheal lymph nodes or in the follow-up after treatment; b) a neck negative to palpation in a subject with carcinoma of the upper aero digestive tract, must be further investigated. The US and the CT must use a cut-off point of 1 cm to consider a neck positive. Radiologic criteria for malignancy, i.e., multiplicity, roundish shape, central necrosis and capsular invasion do not significantly increase the diagnostic accuracy of the radiographic methods; c) the combined use of US and CT does not offer significant advantages in the detection of metastasis, in any case CT is preferable when primary tumor has to be evaluated; d) the assessment of patients that are negative to palpation and to US and to CT must consider the parameters linked with primary tumor, such as site and size, Broder's grading, Invasive Cell Grading, and thickness.

[Follow-up of testicular tumors in the metastatic diffusion phase. Current orientation]

Lymphadenectomy in germinal tumors of the testis, in spite of the immediate morbility (postoperative complications) and of the permanent morbility (unejaculation), is still, as regards the group of non-seminoma neoplasms, the most suitable for survival. However, groups of oncologists are seeking the possibility of avoiding this technique at stage I and II of the lesions, with the help, of course, of careful observation by CT, NMR, markers. The use of combined therapies (chemotherapy and radius therapy) has increased survival and the patients' life, allowing a highly satisfying percentage of recovery also in the non-initial stages.

Ketanserin plus prostaglandin E1 (PGE-1) as intracavernosal therapy for patients with erectile dysfunction unresponsive to PGE-1 alone

OBJECTIVE

To evaluate the treatment of patients with erectile dysfunction and who were unresponsive to intracavernosal injections of prostaglandin E-1 (PGE-1) alone with a combination of PGE-1 and ketanserin, a peripheral vasodilator antagonizing 5-hydroxytryptamine receptors and with mild alpha-blocking effects.

PATIENTS AND METHODS

The study comprised 98 men with erectile dysfunction all of whom received an intracavernosal injection of 5-40 micrograms of PGE-1. The 45 patients unresponsive to the maximum dose of 40 micrograms were selected for further treatment using a combined dose of 40 micrograms PGE-1 and 2-7 mg of ketanserin. Their erectile response was assessed both subjectively, by interviewing the patient and their partner, and objectively using the 'Rigiscan' monitor.

RESULTS

The combined therapy was effective in producing an erection sufficient for sexual intercourse in 34 (76%) of the patients. The combined dose was tolerated well and there were no adverse effects.

CONCLUSIONS

The results of this preliminary study suggest that the combination of PGE-1 and ketanserin may be a therapeutic alternative to the implantation of a prosthesis in patients unresponsive to PGE-1.

[Mepartricin 150.000 (40 mg) vs mepartricin 50.000 U (13 mg) in the treatment of BIP. Double blind clinical trial]

A group of 25 patients with uncomplicated BPH was treated mepartricin 150,000 U (40 mg) once in the evening for 60 days and the results were compared with those obtained in 25 patients treated with mepartricin 50,000 U (13 mg) t.d.s. Efficacy and tolerance of both treatment schemes were good. In the group treated with on single dose at night some symptoms such as nocturia and pollakiuria regressed more rapidly.

[Natural history of prostatic adenocarcinoma. Recent advances in prognostic parameters and biological behavior]

For many years diagnosis and management of prostatic adenocarcinoma were straightforward. However, with the advent of medical and less invasive therapies for the treatment of prostatic cancer, it has become necessary to know more about the etiology and pathophysiology of the disease. For example, hormonal factors, growth factors, stromal-epithelial interactions and aging have all been implicated in the etiology of the disease. The pathology of the disease demonstrates heterogeneity in the ratio of the stroma to the epithelium in any given patient, and the pathophysiology varies. Recognizing this heterogeneity in the disease, it is clear that no one form of medical or interventional therapy should be expected to result in a complete response.

Frequency and cause of aborted laparoscopic-assisted vaginal hysterectomy

STUDY OBJECTIVE

To evaluate the frequency and cause of aborted laparoscopic-assisted vaginal hysterectomies (LAVH) at two hospitals of a major obstetrics and gynecology training program.

DESIGN

Retrospective cohort study.

SETTING

A university hospital and a university-affiliated county hospital.

PATIENTS

Seventy-eight consecutive women who underwent LAVH at our institutions between June 1992 and February 1995.

INTERVENTIONS

Data on age, weight, indications for surgery, obstetric and surgical history, concomitant procedures performed, postoperative diagnosis, perioperative complications, operative time, estimated blood loss, uterine weight, and length of hospital stay were collected from patients' hospital records. Univariate analysis of variance to assess statistical significance was performed when appropriate.

MEASUREMENTS AND MAIN RESULTS

Eight (11.1%) of 78 procedures were converted to abdominal hysterectomy. The most frequent reason for conversion (5 cases, 6%) was large uterine size with limited mobility and associated inability to visualize the pelvic sidewall structures adequately. The other three procedures were converted because of massive intraperitoneal adhesions (2) and intraoperative severe bleeding (1). The mean uterine weight of these eight women (575 g, range 387-1030 g) was significantly higher than that of patients undergoing successful LAVH (230 g, range 35-612; p <0.03).

CONCLUSIONS

In our limited series of 78 patients, only one LAVH was converted to abdominal hysterectomy because of an intraoperative complication. A conversion rate of 11.1% may be appropriate so as to offer the potential benefits of the laparoscopic-assisted vaginal approach to the largest number of women who would otherwise undergo an abdominal hysterectomy.

The subacute levodopa test for evaluating long-duration response in Parkinson's disease

The clinical relevance of a long-duration response (LDR) to levodopa therapy in Parkinson's disease (PD) has not been widely recognized. In 25 patients with moderate PD, we measured LDR on motor function after short periods of treatment with levodopa (subacute tests). Each subacute test lasted 15 days and consisted of the oral administration of levodopa at various interdose intervals (IDIs) of 48, 24, 12, 8, 6, and 5 hours. The goal for a subacute test was to achieve a satisfactory antiparkinsonian effect before the last levodopa dose (day 15), i.e., an LDR greater than 50% of the maximal response following an acute levodopa test (LDR-endpoint). Twenty-one patients (84%) reached the LDR-endpoint. The IDI at which levodopa was administered clearly differentiated patients who were otherwise clinically indistinguishable when evaluated at baseline off medication or after an acute levodopa test. The IDI schedule that produced a satisfactory LDR was specific for each patient, since longer DIs failed to produce the required LDR, and a shorter IDI schedule (resulting in larger cumulative dosage of levodopa) did not significantly enhance the response. Also, the LDR decay rate after discontinuation of treatment was individual for each patient and independent of the cumulative amount of levodopa administered. Both the IDI schedule and the LDR decay rate may reflect the ability of nigrostriatal neurons to store and to release dopamine formed from the exogenous precursor. The assessment of the LDR to levodopa by subacute tests is useful for establishing the appropriate dose of the drug, as well as for developing levodopa sparing strategies in PD patients.

[Laparoscopic surgery in varicocele: description of the technique and preliminary data]

The aim of this work is to remark the scientific worth of the laparoscopic approach in patients with varicocele.

PATIENTS AND METHODS

From March 1993 to December of the same year 15 patients suffering from varicocele have been treated with a laparoscopic procedure. The technique is widely described in the next pages.

RESULTS

Twelve patients have completed the 3 months follow-up whereas five among them have reached the 6 months control. The results are really interesting specially under a functional point of view.

DISCUSSION

The noninvasive advantages provided by laparoscopy are always important, but is the worth of the results we have obtained under a functional point of view and the success in inducing pregnancy in some patients that lead us to remark the utility of this procedure comparing it, with the therapeutic proposals nowadays performed. They are: traditional surgery according to Ivanissevich or Palomo procedures percutaneous transvenous embolization under radiological guide varicocele vein ligation under local anesthesia.

CONCLUSIONS

Laparoscopic varicocelectomy represents according to us and some other authors a proposal with a better response if compared to traditional surgery, specially under a functional aspect. Under a costs-benefits evaluation it may be considered more convenient than the radiological approach.

[Bilateral varicocele: diagnostic implications]

If a varicocele is appreciated on the clinical examination, its presence may then be confirmed by Doppler examination. A pencil-probe Doppler stethoscope is utilized with ultrasonic conduction gel. The patient is examined in the upright position, and conducting medium is applied to the upper aspect of the scrotum. It is important that there is complete acoustic silence prior to having the patient perform the Valsalva maneuver. However, if a clinical varicocele is found on either the left or right side, the opposite side is evaluated for the presence of a "subclinical" varicocele by Doppler examination. When a "subclinical" varicocele is associated with a controlateral clinical varicocele, it is treated at the same time as the coexistent clinical varicocele. Venography is employed for the diagnosis of varicoceles only for patients in whom physical examination and Doppler studies are equivocal but highly suggestive of the presence of a varicocele. In that situation, rather than subjecting the patient to an unnecessary surgical procedure, venography may be employed to confirm the varicocele. Nowadays another diagnostic procedure is successfully used, that consists in a color ultrasound of the scrotum associated with Doppler velocimetry of the spermatic cord.

Slipped capital femoral epiphysis associated with Rubinstein-Taybi syndrome

The association of Rubinstein-Taybi syndrome (RTS) and slipped capital femoral epiphysis (SCFE) is described in a girl aged 9 years and 10 months. SCFE has never been reported associated with RTS, neither as an isolated anomaly, nor in a familial pedigree. However, a "stiff gait" is frequently described in RTS patients and, furthermore, obesity is a frequent feature of RTS patients. Some reports in the literature suggest the need for an early diagnosis of SCFE among adolescent relatives of patients with SCFE. Since many SCFEs are asymptomatic and an early diagnosis is essential for a favorable prognosis, we suggest an annual echotomographic or radiological examination of the hips in RTS patients.

Laparoscopic retrieval of a fractured infuse-a-cath catheter

The laparoscopic approach is being used in an increasing variety of surgical procedures which have traditionally been performed by the gynecologic oncologist in an open fashion. We here report the first published case of laparoscopic retrieval of a detached intraperitoneal catheter.

Verapamil prevents the acute hypertensive response to intracerebroventricular cadmium in conscious normotensive rats

Cadmium, a trace element from natural and industrial sources, may contribute to the pathogenesis of arterial hypertension. We evaluated the effect induced by acute intracerebroventricular (icv) administration of cadmium on mean blood pressure of normotensive conscious rats. Intracerebroventricular cadmium (1 to 10 micrograms) produced a dose-dependent, sustained increase in mean blood pressure. The hypertensive response to icv cadmium was significantly (P < .01) prevented by icv pretreatment with verapamil (10 to 100 micrograms). A preventive effect was exerted also by icv nifedipine (100 micrograms); however, this result was attributable, at least in part, to the antihypertensive action of the vehicle, polyethylene glycol. The hypertensive response to icv cadmium was blunted by icv administration of 10 ng clonidine, 10 micrograms vasopressin antagonist, or 10 micrograms bradykinin antagonist (P < .05), but it was not altered by icv enalaprilat (100 micrograms). These results indicate that brain calcium channels play a role in the hypertensive action induced by icv cadmium. Accumulation of cadmium in the brain caused by prolonged exposure to this heavy metal might lead to chronic arterial hypertension.

[Follicular cysts of the mandible. The diagnostic problems]

The authors describe a case of follicular cyst of the jaw diagnosed in a male infant who was 2 years and 4 months old. The authors discuss recent advances in the classification of this disorder and the difficulties that arise in performing differential diagnosis; some peculiar features of the described case are discussed.

Cranial computed tomography in the phakomatoses

The authors present the CT findings in their personal series of 77 cases of neurofibromatosis, 34 cases of tuberous sclerosis, and 16 cases of Sturge-Weber disease. These findings are extensively illustrated and compared with those reported in the literature.

The current potential of neuroradiology in the diagnosis of tuberous sclerosis

Computed tomography has proved very valuable in the diagnosis of central nervous system changes in tuberous sclerosis. A full analysis of the CT findings in 34 cases is presented. Intracranial calcifications--periventricular, corticosubcortical, within the white substance or in the posterior cranial fossa--were the most frequent finding, followed by parenchymal hypodensities and tumors. Hydrocephalus and atrophy, focal or diffuse, were rare.

Immediate and late effects of ventricular shunting in infantile hydrocephalus

This paper analyzes our findings in a series of 1900 CT examinations carried out on 950 children after ventricular drainage. Blood in the ventricles is a relatively frequent findings in the immediate postoperative course, and gliotic or poroencephalic phenomena are often found in the late course. Persistence of ventricular dilatation and periventricular lucency has been observed several times. Extracerebral collections and septic complications are not rare findings, but trapped fourth ventricle and choroidal-ependymal reactions are only rarely observed.

High resolution CT spinal scanning with Acta 0200 FS

The diagnostic features of CT images of the spine are constantly influenced by some limitations of the method because of the peculiar configuration of the human spine. Recent generations of CT scanners greatly improve the results but with the second generation (Acta 0200 FS Pfizer Scanner) we have been able to develop a modified scan reconstruction method to maintain the quality of our spinal images, thanks to the very flexible software of our CT scanner.

Cerebral damage following ventricular shunt for infantile hydrocephalus evaluated by computed tomography

The result of a late CT control of infantile hydrocephalus is reported with an analysis of effects of the catheter on the cerebral tissue in the immediate and late postoperative course. The most frequent finding is blood in the ventricle and/or subependymal or intraparenchymal along the catheter or near its tip.

Microencapsulation and dissolution parameters of undecenovanillylamide: a potential coyote deterrent

The microencapsulation and dissolution of undecenovanillylamide (I), a potential coyote-aversive agent for use on sheep, were studied. While I has been shown to protect sheep, its short duration of action makes it economically unfeasible. Compound I microcapsules were prepared, and optimum conditions for encapsulation via complex coacervation were determined. Microcapsules that were hardened for 0.5, 1, and 2 hr, as well as I powder, were characterized according to their dissolution. Longer hardening times resulted in slower release, with all encapsulated I forms being released slower than the powder. The dissolution t50 for unencapsulated powder was less than 3 min; for microcapsules hardened for 30 min, the dissolution t50 was 7.3 min; for those hardened 60 min, the t50 was 17.7 min; and for those hardened 120 min, the t50 was 28 min. The encapsulated I would have a longer field life and, therefore, might be a viable economic and ecologic answer to coyote protection for sheep.

Effect of dissolved oxygen levels on oxidative degradation of pyrogallol

Pyrogallol decomposition in aqueous systems with various dissolved oxygen levels was studied. The reduced dissolved oxygen levels were produced by deaeration via gas permeation. Dissolved oxygen levels were determined using a dropping mercury electrode polarograph. Degradation rates, T90, and relative protection indexes are discussed. Even at dissolved oxygen levels of less than 0.05 ppm, some decomposition of pyrogallol occurred, indicating nonoxidative pathways or the necessity of total removal of dissolved oxygen to afford complete protection. Apparently, reducing the level of dissolved oxygen is a viable alternative to stabilization of aqueous pyrogallol solutions, since the T90 was increased from 1.9 days in water with dissolved oxygen levels of 9.05 ppm to 114.4 days in water with dissolved oxygen levels of less than 0.05 ppm.

Role of computed tomography in the postoperative evaluation of infantile hydrocephalus

The value of CT for the diagnosis and followup of infantile hydrocephalus is discussed. The ventricular volume, subependymal periventricular hypodensity, sbudural hygroma or hematoma, position of catheter in the ventricles, ependymal inflammation and other occasional findings are considered.

[Extracranial angioma with dural participation]

Extracranial congenital arteriovenous malformations are often associated with dural and/or cerebral malformations. One case is presented. The angiography of the common carotid artery revealed no evidence of abnormal vessels into the internal or external carotid territory. The injection of contrast medium into an enlarged epicranial vein showed the extracranial malformation, well opacified; the phlebography revealed also a small dural malformation draining in the superior sagittal sinus. The Authors outline the importance of complete angiographic study in all the cases of extracranial vascular malformations even if the carotid angiography is apparently normal.