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Biomedical subjects

I Benjamin

Publications and source records attributed to I Benjamin.

At least 55 records · Page 3Linked to original sources
PubMed1994

OncoLink: a multimedia oncology information resource on the Internet.

This paper describes OncoLink, the first multimedia World-Wide-Web (WWW) and gopher server focusing on cancer information for both the health care professional and the patient. OncoLink provides an internetworked hypertext and multimedia resource linking people, computers and information together in an easy to use fashion. Our objective in developing OncoLink is to provide comprehensive and timely information about many aspects of oncology for both patients and healthcare providers. Specifically, OncoLink's purposes are: (1) the rapid dissemination of information relevant to treatment of cancer and concomitant problems; (2) education of health care personnel (at all levels) in the field; (3) education of patients and families of patients who have cancer; (4) posting of clinical trials and eligibility criteria; (5) the rapid collection and dissemination of quality, peer-reviewed information pertinent to oncology in general and specific subspecialties; (6) provide a well-organized, frequently updated hypertext system to access other quality cancer information resources on the Internet. OncoLink attempts to provide one-stop shopping for the patient, healthcare provider, researcher or Internet browser searching for cancer-related information. Since its inception on March 7, 1994, OncoLink has averaged more than 36,000 accesses per month from around the world. While also accessible by text-based gopher servers, preliminary observations infer increased use of multimedia and hypertext documents over traditional text-only resources. From the large following of users, it is clear that electronic dissemination of high quality, peer-reviewed cancer information is very popular. We conclude OncoLink is both useful and has wide interest in the international community.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Communication Networks↗
PubMed1994

Prompt diagnosis of ectopic pregnancy in an emergency department setting.

OBJECTIVE: To evaluate quantitative hCG measurements and transvaginal ultrasound in the diagnosis of ectopic pregnancy in patients presenting to the emergency department. METHODS: A discriminatory zone for detecting the presence or absence of an intrauterine pregnancy by transvaginal ultrasound was established prospectively. Women presenting to the emergency department were evaluated prospectively using a diagnostic algorithm consisting of clinical examination, quantitative serum hCG, and transvaginal ultrasound. Finally, ectopic pregnancies diagnosed over a 22-month period were evaluated prospectively. RESULTS: All viable intrauterine pregnancies were identified in those subjects with hCG levels of 1500 mIU/mL (First International Reference) or greater. One thousand two hundred sixty-three subjects were evaluated prospectively; 59.8% were diagnosed with intrauterine pregnancy, 26.8% with spontaneous abortion, and 7.8% with ectopic pregnancy. At presentation, 13.2% of intrauterine pregnancies were diagnosed by clinical examination, whereas 82.9% were diagnosed by transvaginal ultrasound. Only 4% of normal intrauterine pregnancies were not confirmed on initial visit. Of 205 ectopic pregnancies diagnosed, 81.5% were hemodynamically stable; of these, 49.1% were diagnosed on initial presentation. Of all ectopics, 59% never reached an hCG level of 1500 mIU/mL and 35.8% had an hCG lower than the level at presentation. This protocol diagnosed ectopic pregnancies with a sensitivity of 100% and a specificity of 99.9%. CONCLUSION: A protocol of quantitative hCG levels (available within hours of presentation to an emergency department) combined with transvaginal ultrasound is effective in diagnosing ectopic pregnancy.

Chorionic Gonadotropin↗
PubMed1994

Blood transfusion for radical hysterectomy before and after the discovery of transfusion-related human immunodeficiency virus infection.

OBJECTIVE: To compare the patterns of perioperative blood transfusion in patients undergoing radical hysterectomy in time periods before and after the discovery of transfusion-related human immunodeficiency virus (HIV) infection. METHODS: We reviewed the medical records of all patients who underwent radical hysterectomy and pelvic lymphadenectomy at Memorial Sloan-Kettering Cancer Center during two time periods, an early period (January 1, 1980 through December 31, 1993) and a late period (July 1, 1991 through June 30, 1993). The early period preceded and the late period coincided with the era of increased awareness of transfusion-related HIV infections. RESULTS: One hundred twenty-eight patients underwent radical hysterectomy in the early period and 71 in the late period. In the late period, markedly fewer units of blood were transfused per patient (0.62 versus 3.5). Most patients in the early period received at least one unit (117 of 128, 91%), compared with less than half (31 of 71, 44%) in the late period. For patients who received transfusions, notably fewer received homologous blood during the late (6 of 31, 19%) versus the early period (117 of 117, 100%). Using an unpaired t test and the 95% confidence interval (CI), we found that the patients in the late period had a shorter mean postoperative length of stay (11 versus 14 days, P < .0001, 95% CI +/- 1.3) and were discharged with a significantly lower mean hemoglobin level (9.7 versus 11.4 g/dL, P < .0001, 95% CI +/- 0.35). The mean estimated blood loss was lower in the late period (756 versus 1598 mL). We defined the transfusion index as the number of units transfused per 500 mL of estimated blood loss. The mean transfusion index was significantly lower during the late period (0.38 versus 1.1, P < .001, 95% CI +/- 0.19). CONCLUSIONS: During the perioperative period for radical hysterectomy and pelvic lymphadenectomy, the incidence of blood transfusion at our institution has markedly decreased over the past decade without immediate adverse effects on postoperative recovery. The reasons for this are probably multifactorial. However, the contribution of increased concern about transfusion-related HIV infections must be considered. Preoperative autologous donation can notably decrease the need for homologous transfusion.

Adult↗
PubMed1994

Management of early-stage epithelial ovarian cancer.

Because ovarian cancer is asymptomatic until the late stages of the disease and because accurate methods of early detection are lacking, only about 40% of these cancers present in stages I and II. As a result, ovarian carcinoma remains the leading cause of death from gynecologic malignancy in the United States. However, proper management of early cases may lead to a good prognosis for long-term survival and, in some cases, may even permit preservation of reproductive capacity. The appropriate management of these early cases includes meticulous and thorough staging at the time of the initial surgery. In women who do not desire further reproduction, total abdominal hysterectomy and bilateral salpingo-oophorectomy should be carried out. In those who eagerly wish to maintain reproductive potential, the uterus and contralateral ovary may be preserved, providing certain criteria have been met. Patients with stage Ia or Ib grade 1 disease can be followed-up without further therapy after definitive surgery; those with Ic or grade 3 tumors should receive adjuvant therapy. Patients with stage I epithelial ovarian cancer who are without evidence of disease after comprehensive staging surgery and primary adjuvant chemotherapy do not require second-look laparotomy. In the future, laparoscopy will play an increasingly important role in the diagnosis and management of early-stage epithelial ovarian cancer.

Combined Modality Therapy↗
PubMed1993

Isomerization reaction dynamics and equilibrium at the liquid-vapor interface of water. A molecular-dynamics study.

The gauche-trans isomerization reaction of 1,2-dichloroethane at the liquid-vapor interface of water is studied using molecular-dynamics computer simulations. The solvent bulk and surface effects on the torsional potential of mean force and on barrier recrossing dynamics are computed. The isomerization reaction involves a large change in the electric dipole moment, and as a result the trans/gauche ratio is considerably affected by the transition from the bulk solvent to the surface. Reactive flux correlation function calculations of the reaction rate reveal that deviation from the transition-state theory due to barrier recrossing is greater at the surface than in the bulk water. This suggests that the system exhibits non-Rice-Ramsperger-Kassel-Marcus behavior due to the weak solvent-solute coupling at the water liquid-vapor interface.

Carbon↗
PubMed1993

Structure and Energetics of model amphiphilic molecules at the water liquid-vapor interface. A molecular dynamics study.

A molecular dynamics study of adsorption of p-n-pentylphenol at infinite dilution at the water liquid-vapor interface is reported. The calculated free energy of adsorption is -8.8 +/- 0.7 kcal/mol, in good agreement with the experimental value of -7.3 kcal/mol. The transition between the interfacial region and the bulk solution is sharp and well-defined by energetic, conformational, and orientational criteria. At the water surface, the phenol head group is mostly immersed in aqueous solvent. The most frequent orientation of the hydrocarbon tail is parallel to the interface, due to dispersion interactions with the water surface. This arrangement of the phenol ring and the alkyl chain requires that the chain exhibits a kink. As the polar head group is being moved into the solvent, the chain length increases and the tail becomes increasingly aligned toward the surface normal, such that the nonpolar part of the molecule exposed to water is minimized. The same effect was achieved when phenol was replaced by a more polar head group, phenolate. This result underscores the difference between hydrophobic hydration at the surface and in the bulk solvent, when nonpolar molecular fragments adopt compact conformations.

Adsorption↗
PubMed1993

Surgery for malignant gynecologic disease.

The surgical management of malignant gynecologic disease continues to evolve as more is learned about the natural history and biology of these neoplasms. Whereas curing malignancies remains the ultimate goal of most surgical procedures for gynecologic cancers, the importance of quality of life cannot be ignored. Surgical procedures that enhance the quality of life without compromising cure continue to be explored. In vulvar cancer, the disfiguring classical radical vulvectomy is being replaced by more conservative procedures. As anesthetic techniques and postoperative care continue to improve, the role of radical surgery for invasive and recurrent cervical cancer has been extended to include older women. Ovarian cancer continues to be the most lethal of all gynecologic malignancies, and the role of aggressive primary and secondary cytoreduction continues to be defined. The new International Federation of Gynecology and Obstetrics staging system for endometrial cancer has generated controversy regarding the benefits and morbidity associated with surgical staging.

Female↗
PubMed1991

Molecular dynamics of phenol at the liquid-vapor interface of water.

Molecular dynamics results are presented for phenol at the water liquid-vapor interface at 300 K. The calculated excess free energy of phenol at the interface is -2.8 +/- 0.4 kcal/mol, in good agreement with the recent experimental results of Eisenthal and co-workers. The most probable orientation of the phenol molecule at the surface is such that the aromatic ring is perpendicular to the interface and the OH group is fully immersed in water. The hydroxyl substituent has a preferred orientation which is similar to the orientation of OH bonds of water at the pure water liquid-vapor interface. The transition between interfacial and bulk-like behavior of phenol is abrupt and occurs when the center of mass of the solute is located about 6 angstroms from the Gibbs surface of water. In this region the para carbon atom of the hydrophobic benzene ring can reach the interface and become partially dehydrated. This result suggests that the width of the interfacial region in which the behavior of a simple amphiphilic solute in water is influenced by the presence of the surface depends primarily on the size of its hydrophobic part. The role of the OH substituent was investigated by comparing phenol at the interface with two model systems: benzene with and without partial charges on carbon and hydrogen atoms. It is shown that in the absence of the hydrophilic substituent the solute is located further away from the liquid phase and is more likely to be oriented parallel to the interface. However, when the center of mass of the solute is moved into the interfacial region where the density of water approaches that of the bulk solvent, all three molecules become oriented perpendicularly to the surface. In this orientation the work of cavity formation needed to accommodate the hydrophobic ring in aqueous solvent is minimized.

Algorithms↗
PubMed1990

Database management for a gynecologic oncology service.

With the ready availability of powerful desktop computers, the ability to manage large clinical databases has become practical. A computer can enhance the capability of a gynecologic oncology service to catalog, recall, and analyze data about patients, tumors, and therapies. While commercially available database packages can be used for this purpose, we have developed a custom database for tracking the clinical activity of a busy gynecologic oncology service. The system catalogs data about patients, admissions, tumors, and therapeutic modalities and uses this information to generate several useful reports. The reports are used for daily patient care, fellow and resident case statistics, and clinical research. What is unique about the system is that it is optimized for ease of use. The development of this tumor registry, its user friendliness, and advantages over a manual recordkeeping system are described. Unlike other tumor registries, our system is utilized on a daily basis for patient care. Therefore, the data being entered have an immediate usefulness in addition to being simultaneously added to the tumor register for retrospective clinical research. One may hypothesize that it would be useful if all gynecologic oncology services used a common computerized tumor registry that could allow for the sharing of information on a national or global scale.

Database Management Systems↗
PubMed1989

Palliative surgery for intestinal obstruction in advanced ovarian cancer.

Intestinal obstruction in ovarian cancer patients is a major complication which frequently affects survival and quality of life. After a reasonable trial of conservative management fails, surgery is the only hope for relief of obstruction. In an effort to evaluate the success of such surgery we have reviewed the outcome of 54 operations (52 patients) for relief of intestinal obstruction performed over the 3-year period 1983-1985. Possible predictive factors for success and survival following surgery were analyzed. The sites of intestinal obstruction in the 54 procedures were as follows: small intestine 24 (44%); large intestine 18 (33%); combined small and large intestine 12 (22%). In 11 operations no surgical correction of the obstruction was possible. In 43, major intestinal procedures were performed, including 14 bypasses, 13 resections, and 20 colostomies. Of the 43 instances in which intestinal procedures were performed, 4 patients expired without leaving the hospital. At the time of discharge from the hospital the remaining 34 of these 43 patients were eating a regular or low-residue diet. Successful palliation of intestinal obstruction was thus achieved in 79% of the 43 instances in which a definitive procedure could be performed, and in 63% of the total of 54 operations. Mean survival following surgery was 6.8 months for the group undergoing a definitive procedure, and 1.8 months for the group undergoing exploration only. There was no significant difference between the two groups with regard to age, time from diagnosis, prior radiotherapy, number of prior laparotomies, site of obstruction, or use of total parenteral nutrition. None of the multiple clinical variables analyzed correlated with survival following definitive surgery. Most patients explored for intestinal obstruction due to advanced ovarian cancer can have their obstruction relieved and be discharged from the hospital. We were not able to define criteria that would allow selection of patients unlikely to benefit from surgery.

Adult↗
PubMed1989

Intestinal surgery in gynecologic oncology.

Intestinal surgery is frequently required in the management of patients with gynecologic malignancies. During a recent 3-year period 10.4% of all laparotomies performed on the Gynecology Service at Memorial Sloan-Kettering Cancer Center included major intestinal surgery. A total of 215 separate intestinal procedures were performed during 171 operations on 158 patients. The majority of operations were performed in patients with ovarian (42.7%), cervical (24%), and endometrial (12.3%) malignancies. Seventy-nine of 171 (46.2%) of operations were performed on previously irradiated patients. The most frequent indications for intestinal surgery were intestinal obstruction (43.2%) and intestinal fistula (21%). Procedures performed included 87 intestinal resections, 26 intestinal bypasses, 82 colostomies, and 20 intestinal conduit urinary diversions. Hand suturing was used in 71% of anastomoses; automatic stapling instruments were used in 29%. There was a single surgical mortality. Complications including infections, obstruction, and fistula formation were infrequent. These difficult intestinal procedures can be performed safely in the context of a fellowship training program. Since a significant proportion of all laparotomies done in gynecologic cancer patients will include major intestinal surgery, physicians managing patients with these diseases should have both the technical skills necessary to perform these procedures, as well as a thorough understanding of the diseases themselves.

Female↗
PubMed1988

Bypass of obstructing bile duct calculus by an endoprosthesis inserted via a T-tube track.

A surgically introduced biliary endoprosthesis in a patient with a cholangiocarcinoma prevented extraction of a calculus in the lower common bile duct through a T-tube track. The problem was solved by the introduction of a second endoprosthesis across the ampulla of Vater through the T-tube track in order to prevent obstruction of the common bile duct by the calculus.

Adenoma, Bile Duct↗
PubMed1983

Histiocytic lymphoma (reticulum-cell sarcoma) of the tongue manifesting as macroglossia.

A case of histiocytic lymphoma primarily involving the tongue in a 71-year-old black man is presented. The authors discuss the diagnostic problems in differentiation of such lesions from other small-cell tumors, primary or secondary, that might involve the tongue. Electron microscopic studies were utilized to confirm the diagnosis of histiocytic lymphoma.

Aged↗