Early response of quiescent cells to sv40 virus-infection

Infection of G(0) arrested NIH3T3 fibroblasts with SV40 induces quiescent cells to re-enter the cell cycle and to initiate cellular DNA synthesis. We analyzed the contribution of second messengers to the stimulation of cellular DNA synthesis by SV40 infection of quiescent cells. A rapid increase in the intracellular Ca2+ ion concentration and a decrease in the intracellular cAMP concentration was found. An elevated cAMP level is incompatible with the stimulation of cellular DNA synthesis by SV40 infection of quiescent cells. Thus, overcoming the cAMP sensitive restriction point seems to be an early event after SV40 infection of quiescent cells. These data demonstrate that signal transduction mechanisms are implicated in early response to SV40 infection of quiescent cells.     

Mini-swim-up: A new technique of sperm preparation for intracytoplasmic sperm injection

Purpose The male factor is nowadays one of the major problems in the treatment of infertility. New methods of assisted fertilization such as the intracytoplasmic sperm injection (ICSI) show better fertilization and pregnancy rates than classical IVF.Method In this study, we present a new technique of sperm preparation: the mini-swim-up.Conclusion This technique, used in conjunction with the ICSI procedure, improves pregnancy and fertility rates in cases of severe oligoasthenoteratozoospermia.     

Limitations in the use of tubulin polymerization assays as a screen for the identification of new antimitotic agents: The potent marine natural product curacin A as an example

Curacin A is a newly isolated lipid natural product that binds in the colchicine site of tubulin and inhibits mitosis. We have examined its effects on tubulin polymerization, studied by turbidimetry, under three reaction conditions. In 1.0 M glutamate + 1.0 mM MgCl₂, with a 37°C reaction temperature, we could find no concentration of curacin A that completely inhibited polymerization. A maximal inhibitory effect on turbidity development (about 50%) was observed with 5 m?M drug. Higher drug concentrations induced an abnormal polymerization reaction, which at 40 m?M differed little from the control reaction except for slightly delayed depolymerization in response to reducing the temperature to 0°C. In 0.8 M glutamate (no MgCl₂), with a 30°C reaction temperature, complete inhibition did occur at 3–5 m?M drug, but higher drug concentrations again induced an abnormal polymerization reaction. With 40 m?M curacin A this reaction was also similar to the control reaction, except that cold-induced depolymerization was slightly enhanced relative to the control. When polymerization was induced by microtubule-associated proteins, maximal inhibition of turbidity development (about 70%) occurred with 2 m?M drug, with higher curacin A concentrations inducing abnormal polymerization reactions that reached about 60% of the control turbidity readings. Under all three reaction conditions the polymer induced by high concentrations of curacin A consisted of large aggregates of tightly coiled spiral fibers that had a 2–3 filament substructure. The implications of these findings with curacin A are discussed in terms of the use of tubulin polymerization assays as a screen for identifying new antimitotic drugs. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

How expensive are unlimited substance abuse benefits under managed care?

Substance abuse (SA) care has been excluded from recent federal and state legislation mandating equal benefits for mental health and medical care (parity), largely because of cost concerns. This article studies how many patients are affected by SA coverage limits and the likely implications of limits on insurance payments, using 1996–97 claims from 25 managed care plans with unlimited SA benefits. Changing even stringent limits on annual SA benefits has a small absolute effect on overall insurance costs under managed care, even though a large percentage of SA patients are affected. Removing an annual limit of $10,000 per year on SA care is estimated to increase insurance payments by about 6 cents per member per year, removing a limit of $1,000 increases payments by about $3.40. As long as care is comprehensively managed, parity for SA in employer-sponsored health plans is not very costly.     

Positron Emission Tomography in Grading Soft Tissue Sarcomas

Soft tissue sarcomas present with varied radiological appearances. Positron imaging with [F-18] fluorodeoxyglucose (FDG PET) has recently made promising contributions to management of patients by providing a noninvasive means for evaluating tumor metabolism and providing important biological information about soft tissue malignant tumors. PET imaging not only gives quantitative data on metabolic rates of tumors but can also readily provide semiquantitative data of uptake of tumors by measuring uptake ratios. These values have been helpful for noninvasively grading tumors. This value is called the tumor standard uptake value (SUV). The tumor grades (low, intermediate, high) mean SUV values show a high level of significance in discrimination among tumor grade groups.     

Lateral transperitoneal laparoscopic adrenalectomy

Several laparoscopic approaches to the adrenal gland have been described. The lateral transperitoneal approach has several distinct advantages when contrasted with other techniques for laparoscopic adrenalectomy (LA). We present our technique and results obtained in 50 consecutive transperitoneal LAs. We review 50 consecutive laparoscopic adrenalectomies (28 female, 19 male) performed from 1993 to 1998. S.J. Shichman or R.E. Sosa was either the primary surgeon or the first assistant for all cases. The lateral transperitoneal approach described below was used in all cases. Indications for adrenalectomy included Cushing's syndrome (13), aldosteronoma (15), pheochromocytoma (7), nonfunctioning adenoma (11), hyperplasia (2), and 1 case each of Carney's syndrome and metastasis to the adrenal gland. We performed 5 bilateral, 22 left, and 18 right laparoscopic adrenalectomies. The average time needed for bilateral adrenalectomy was 503 min (range 298–690 min); for left adrenalectomy, 227 min (range 121–337 min); and for right LA, 210 min (range 135–355 min). We demonstrated a yearly trend in lower operative times. The largest adrenal gland removed measured 13.8 × 6.7 × 3.5 cm. Intraoperative blood loss was low. Only one patient received a blood transfusion. Conversion to open adrenalectomy was not required. Postoperative analgesic requirements were low. The average length of stay was 3.8 days for bilateral LA and 3 days for unilateral LA. Complications occurred in 5 patients (2 wound infections, 2 hematomas, and 1 pleural effusion). There was no mortality. Lateral transperitoneal adrenalectomy is a safe and efficient technique for the removal of functional and nonfunctional adrenal masses. This technique is associated with low morbidity, a minimal postoperative analgesic requirement, and a short hospital stay and, in our opinion, is more versatile than the retroperitoneal approach.     

A phase II study of Didemnin B (NSC 325319) in advanced malignant melanoma: an Eastern Cooperative Oncology Group study (PB687)

Purpose: Didemnin B is a novel marine natural product cyclic depsipeptide containing unusual amino acid moieties. This agent demonstrates promising preclinical antitumor activity, including activity against B16 melanoma and against melanoma isolates in the human tumor stem cell assay.Methods: We conducted a phase II study of Didemnin B, given in Cremophor, at a starting dose of 4.2 mg/m2/IV q 28 days. Patients with measurable metastatic or advanced malignant melanoma were eligible. All patients were previously untreated with chemotherapy and had performance status 0 or 1. Doses were escalated to 4.9 and 5.6 mg/m2 in cycles 2 and 3, respectively.Results: Nineteen patients were entered and treated with a median of one cycle per patient. Eight of these patients went off study for toxicity including 7 with anaphylactoid reactions in the first or second cycle. One patient went off study after 3 cycles with severe myopathy, a newly described toxicity. Two were not evaluable for response and five were considered stable, including one patient with a transient PR of soft tissue disease in the first cycle. Another patient had stable disease for twelve cycles before progressing and one went off study electively after 3 cycles, for a total of 7 patients with stable disease. One patient with a measurable partial remission (PR) and went off study after three cycles due to severe myopathy, a then newly-described toxicity. No hematologic toxicity was seen. Nausea and vomiting were controlled with anti-emetics.Conclusions: This study was indeterminate with respect to the activity of Didemnin B in melanoma. Signs of activity were seen, particularly in soft tissue masses, though a large number of patients could not be evaluated fully for activity due to the occurrence of anaphylactoid reactions. This study does not preclude a clinically important level of activity for Didemnin B.     

Clearance of thallium-201 from the peripheral blood: Comparison of immediate and standard thallium-201 reinjection

As several reinjection procedures have shown encouraging results in terms of imaging, we investigated whether the kinetics of thallium-201 would differ between the standard stress-redistribution-reinjection approach and the stress-immediate reinjection approach. In 53 consecutive patients with undiagnosed chest pain, 75 MBq (2 mCi)²⁰¹Tl was injected at maximal exercise. In 26 of these patients (group I), 37 MBq (1 mCi)²⁰¹Tl was reinjected immediately after completing the exercise images (the immediate reinjection procedure) and in 27 patients (group II), 37 MBq (1 mCi)²⁰¹Tl was reinjected after completing 3-h redistribution images (the standard reinjection procedure). Mean peak²⁰¹Tl blood activity after exercise was 17.7±12.5 kBq/ml (4.8±3.4 mCi/ml) for group I versus 16.4±9.2 kBq/ml (4.4±2.5 mCi/ml) for group II (NS). The relative increase in²⁰¹Tl blood activity after reinjection of half the initial dose [37 MBq (1 mCi)] exceeded 50% of the initial peak in both groups. The relative amount of²⁰¹Tl delivered to the myocardium was assessed by the area under the curve after both exercise and reinjection, and was 117%±72% for group I and 112%±73% for group II (NS). Blood clearance of²⁰¹Tl was at least biexponential. Mean early decay constants (₁) after exercise and reinjection were 0.30±0.18 min^–1 and 0.22±0.046 min^–1 respectively for group I (T _1/2 2.3 min and 3.2 min respectively, NS), and 0.30±0.12 min^–1 and 0.24±0.07 min^–1 respectively for group II (T _1/2 2.3 min and 2.9 min respectively, NS). For both procedures no significant differences were found between ₁ after exercise and ₁ after injection. The mean late clearance (₂) from the blood was 0.032±0.056 min^–1 and 0.012±0.012 min^–1 respectively for group I (T _1/2 21.6 min and 57.7 min respectively, NS), and 0.036±0.030 min^–1 and 0.014±0.014 min^–1 respectively for group II (T _1/2 19.3 min and 49.5 min respectively, NS). Also, no significant differences were found between ₂ after exercise for both groups and between ₂ after reinjection for both groups. We conclude that reinjection of 37 MBq (1 mCi)²⁰¹Tl (half the initial dose) results in a relative increase in the initial peak and a relative increase in the amount of²⁰¹Tl delivered to the myocardium of more than 50% for both the standard and the immediate reinjection procedure. The clearance of²⁰¹Tl from the blood was not influenced by exercise or by the time of reinjection. Based on²⁰¹Tl kinetics as measured in the peripheral blood, there is no reason to postpone reinjection until 3–4 h following exercise.     

Prevalence and prevention of mental health problems in an energy-affected community

Energy-impacted communities experience rapid population growth due to energy resource production. A high prevalence of psychological and social problems are frequently reported in such communities. The present research employed a standardized instrument and random sampling in a community needs assessment to document high prevalence of problems in an energy-impacted town that has attempted to plan for rapid growth. At least 35 percent of the men and 25 percent of the women randomly sampled in the community reported elevated levels of psychological distress; 48 percent of the men admitted to alcohol problems. How the local mental health center utilized the needs assessment results to improve services, obtain funding for needed programs, and generally promote the community's quality of life is described. Recommendations for social planning that go beyond the brick and mortar approach to community planning are provided; prevention services are recommended above traditional remedial mental health services for such circumstances.Tom Bougsty, Ph.D., and Prudy Marshall, Ph.D., are both at the SEW Mental Health Center in Cheyenne WY. Ernest Chavez, Ph.D., is at the Colorado State University at Fort Collins, CO. Requests for reprints should be directed to the first author at 118 W. 4th Ave., Cheyenne, WY 82001.     

Changes in inositol 1,4,5-trisphosphate mass in agonist-stimulated human neutrophils

Changes in the endogenous synthesis of inositol 1,4,5-trisphosphate (IP₃) mass have been quantitated in human peripheral neutrophils stimulated with FMLP, LTB₄ and PAF using a recently described, highly specific radioreceptor assay. Each agonist induced a concentration-dependent synthesis of IP₃ which was detectable within 10 seconds after stimulation. IP₃ production was short-lived, returning to basal levels within 90 seconds. The maximal stimulated level of IP₃ in response to FMLP and LTB₄ was 30–50 pmoles/10⁷ neutrophils. PAF was more effective (100 pmoles IP₃/10⁷ neutrophils). The response to FMLP was inhibited by pertussis toxin, but was unaffected by cholera toxin. Pretreatment with cytochalasin B did not enhance IP₃ synthesis. These findings are generally consistent with previous studies employing [³H]myo-inositol-prelabeled cells, and provide one of the first measurements of IP₃ synthesis by mass in agonist-stimulated human neutrophils.